Archive for the ‘FAQ’ Category

What file types are used for PCB design?

Monday, September 2nd, 2024

What file type is used for pcb designs?Generally, PCB boards require Gerber files, drilling files, bill of materials (BOM), manufacturing drawings and assembly drawings. The Gerber file suffix is .gbr, the drilling file suffix is (.drl), and the PCB schematic file suffix is .schdoc. The drilling file is usually in Excellon format (.xin). The center coordinate file is also called the pick and place file, which is provided in CSV (comma separated value) format.

Ｗhether it is an individual or a company making PCB boards, PCB boards generally require Gerber files, drilling files, bill of materials (BOM), manufacturing drawings and assembly drawings. Among them, Gerber files are a set of files, which are the most important and contain information about each layer of the PCB to be used in production.

What files do I need to make a PCB?

Making PCBs (printed circuit boards) requires a series of files to ensure the smooth progress of the manufacturing process and the quality of the product.

‌Gerber file‌: This is the most common and crucial file in PCB manufacturing. It contains the geometric information of each layer of the PCB, such as copper lines, pads, solder mask layers and silk screen layers, and also includes separate files for each PCB layer, such as top copper, bottom copper, solder mask, silk screen layer, etc. ‌

What file types are used for PCB design?

‌Drill file‌: Provides drilling coordinates and size information for PCBs, and specifies the aperture size of components, vias and mounting holes. Drill files are usually generated in Excellon format or as separate ASCII files‌.

‌Bill of Materials (BOM): A BOM is a detailed list of all components used in a PCB design, including information such as part number, component value, description, and quantity, which helps ensure that all required components are correctly sourced and placed on the PCB.

‌Center Coordinate File: Also known as a pick and place file, it provides coordinate and orientation information for each component on the PCB and is essential for the automated assembly process. Center coordinate files are usually provided in CSV format.

‌Fabrication Drawing: This is an engineering drawing that includes key information about the PCB, such as board dimensions, drill hole dimensions, layer stackup, tolerances, surface finish, and other manufacturing-related details, which serves as a reference for PCB manufacturers during the production process.

‌Assembly Drawing: Provides additional information for the PCB assembly process, including component placement details, reference numbers, orientation, and any special instructions for assembly technicians.

In addition, depending on the specific design and production needs, other documents may also be required, such as circuit diagrams, special layer files, installation instructions and precautions, etc. ‌ The preparation and provision of these documents is a key step in ensuring a smooth PCB production process.

What are Gerber files? What information do they contain?

Gerber files are a series of ASCII vector format files that define PCB design specifications. They are generated using electronic design automation (EDA) or computer-aided design (CAD) tools and provide information such as board configuration parameters, aperture descriptions, XY coordinate locations, and drawing instructions.

Configuration details include the size and shape of the PCB to be manufactured. Each layer of the board information is recorded in a different file to define components such as copper traces, pads, vias, solder mask, silk screen, and logos. The Gerber file indicates the XY coordinate location of each geometric shape and uses instructions to draw these shapes on the physical board.

The basic components of the Gerber file include: board size, shape, top assembly, top silk screen, top solder mask, top paste, top copper, internal signals, inner layers, bottom copper, bottom paste, bottom solder mask, bottom silk screen, bottom assembly, and manufacturing information (providing stackup, drilling details, cutting, etc.).

Gerber files generated by computer-aided manufacturing (CAM) tools have user-selected extensions, usually using project naming such as “.TOP” for top layer, “.BOT” for bottom layer, and “.drl” for drill data.

How is a PCB designed?

PCB design is a complex process that involves multiple steps and considerations to ensure the functionality and reliability of the final product.

‌Schematic Design‌: First, you need to prepare a schematic and component library. The schematic is the blueprint of the circuit design, while the component library contains information about the various components used in the circuit.

‌Component Symbols and Packages‌: The symbol of the component is used to represent the component in the schematic, while the package defines the physical form of the component on the PCB. The component symbol is used in the schematic design stage, while the package is used in the PCB layout and routing stages.

How is a PCB designed?

‌PCB Layout‌: The layout stage involves placing electronic components on the PCB, and factors that need to be considered include the orientation, size, and relative position of the components.

‌Routing‌: After the layout is completed, the next step is the routing stage, which is to connect the various components according to the needs of the circuit.

‌DRC Check‌: Design rule checking (DRC) is performed during the design process to ensure that the design complies with predetermined electrical and physical rules. This includes checking for shorts, open circuits, and other possible design errors.

‌Solder mask and solder paste layer‌: The solder mask is used to prevent unnecessary soldering, while the solder paste layer is used to specify solder joints. The correct design of these layers is critical to ensuring the reliability and manufacturability of the circuit board.

‌Network and DRC Check‌: In the final stage of design, network checks are performed to ensure that all components are properly connected, while DRC checks are performed to verify that the design complies with all electrical and physical rules.

‌Through the above steps, designers are able to transform the circuit design in the schematic into an actual, manufacturable PCB. This process requires comprehensive consideration of multiple factors such as the functionality, reliability, and manufacturing cost of the circuit.

‌What is the schematic file for PCB?

‌PCB schematic files are the main files used for circuit design, analysis, and debugging. They mainly show the electrical connection relationship between electronic components, but do not reflect the actual physical location of these components on the PCB board. ‌

Schematic Diagram is the basis of circuit design. It uses symbols and lines to express the connection and working principle of the circuit in a concise and clear manner, and pays more attention to the functional expression of the circuit.

Schematic diagram does not involve the specific layout and wiring of electronic components on the PCB board, so it focuses on the logical representation of the circuit rather than the physical implementation. ‌

In contrast, PCB design files plan the precise location and wiring of electronic components on the PCB board in detail, taking into account the connectivity of the circuit, and also comprehensively considering factors such as signal integrity, power distribution, thermal design, and mechanical strength. ‌

These design files are the main files used to manufacture actual electronic devices, including PCB layout and PCB wiring. The layout determines the location of electronic components on the circuit board, while the wiring involves the electrical connection between components. ‌

In general, schematic files and PCB design files play different roles in the design and manufacturing process of electronic products. The former focuses on the expression of circuit logic and function, while the latter focuses on converting this logic into actual physical implementation, including the specific location and connection method of components. ‌

What is the difference between PCB design and schematic design?

The main difference between PCB design and schematic design lies in their purpose, content and application scenarios. ‌

‌Purpose and content‌:

Schematic design focuses on describing the logical relationship and electrical performance of the circuit, using graphic symbols to display power, components and connections, and can clearly show the logical relationship of the internal circuit of the electronic device. It is mainly used for circuit analysis and design, helping to understand the working principle of the equipment and perform fault diagnosis‌.

PCB design focuses on describing the actual physical size, position and wiring of components, and is the actual circuit board layout and wiring design based on the schematic diagram. It is mainly used to guide the manufacture and assembly of PCBs, reflecting the actual layout and wiring of electronic equipment‌.

‌Application scenarios‌:

Schematic design plays an important role in the process of R&D, debugging and maintenance, and is a key tool for understanding the working principle of the equipment and performing fault diagnosis‌.

PCB design files are an important basis for the actual PCB board manufacturing and subsequent assembly, debugging and other processes‌.

In short, schematic design is the basis of electronic product development. It provides information such as the logical relationship and electrical performance of the circuit, while PCB design is the key link to convert the schematic into an actual circuit board. It is necessary to design components layout and wiring according to the requirements of the schematic.

What is a PCB stencil file?

A PCB stencil file is a pre-designed file template used to quickly generate PCB design files containing specific information.

These template files usually contain basic information such as board size, board layer settings, grid settings, and title bar settings. Users can quickly generate new PCB design files based on these templates, thereby speeding up the design process.

By using these templates, designers can avoid designing these basic settings from scratch, saving time and energy, and focusing on more complex circuit design details.

Conclusion:

There are many types of PCB design files, among which Gerber files are the most important. The information they contain is the most and the most important. The final quality of the PCB circuit board depends on the first step of design. BEST Technology has very professional PCB designers who have many years of industry experience and can meet all your needs.

Tags:PCB, pcb design, PCBA, printed circuit board
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What is BGA? What is its use?

Friday, August 30th, 2024

Ball grid array (BGA) is a surface mount package for integrated circuits. Its ability to accommodate a large number of pins while maintaining a small footprint makes it ideal for modern electronic devices with limited space. BGA packages are used in a variety of applications, from consumer electronics such as smartphones and laptops to industrial equipment and automotive systems.

What is BGA?

Ball grid array (BGA) is a common surface mount package that is derived from pin grid array (PGA) technology. It uses a grid of solder balls or leads to conduct electrical signals from the integrated circuit board. Instead of using pins like PGA, BGA uses solder balls placed on a printed circuit board (PCB). By using conductive printed wires, PCBs support and connect electronic components.

Unlike PGA, which has hundreds of pins and is difficult to solder, BGA solder balls can be evenly distributed without accidentally connecting them together. Solder balls are first placed in a grid pattern on the bottom of the package and then heated. By using surface tension when melting the solder balls, the package can be aligned with the circuit board. The solder balls cool and solidify, with accurate and consistent distances between each other.

What does a BGA do?

The main role of BGA (Ball Grid Array) packaging technology includes providing high-density, high-performance packaging solutions for microprocessors, ASICs, DSPs, PDAs, PLDs and other devices. This technology achieves surface mounting by making array solder balls on the bottom of the package substrate as the I/O end of the circuit to interconnect with the printed circuit board (PCB).

BGA packaging technology is small, light, and high-performance. It can provide more pins than other packaging technologies such as dual in-line package (DIP) or quad flat package (QFP). The entire bottom surface of the device can be used as pins instead of only the periphery.

This allows BGA packages to have shorter average wire lengths than periphery-limited package types, thereby providing better high-speed performance.

The advantages of BGA packaging are not only its high density and high performance, but also its less stringent requirements for welding accuracy. Even during the soldering reflow process, even if the solder ball is offset from the pad, the device position can be automatically corrected due to the surface tension of the solder.

What are the disadvantages of BGA?

The disadvantages of BGA packaging technology mainly include difficulty in detection, high difficulty in repair, relatively high production cost, stricter requirements on the reliability of solder joints, and sensitivity to temperature and humidity. ‌

1. Difficulty in detection: Since the solder ball is located at the bottom of the chip, the traditional optical inspection method cannot effectively detect the welding quality, and X-ray detection and other equipment must be used, which increases the cost and time of detection. ‌

2. High difficulty in repair: If there is a welding problem, the BGA packaged device needs to be disassembled and reassembled. This process has high technical requirements and certain risks. ‌

3. Relatively high production cost: Compared with QFP packaging, BGA packaging has higher material, production and inspection costs. ‌

4. More stringent requirements on the reliability of solder joints: Due to its small size, the BGA packaging method has very high requirements on solder joints. If there are problems such as empty solder joints and cold solder joints in the solder joints, the BGA package will fail.

5. Sensitive to temperature and humidity: BGA packaged components are very sensitive to temperature and humidity and need to be stored under constant temperature and dry conditions.

These shortcomings have limited the widespread application of BGA packaging technology to a certain extent, especially in application scenarios with high requirements for cost, reliability and environmental adaptability.

How is BGA made?

The production process of BGA (ball grid array package) mainly includes several key steps, which ensure the high quality and high reliability of BGA package. ‌

1. Wire bonding PBGA packaging process flow:

Substrate preparation: extremely thin copper foil is laminated on both sides of the BT resin/glass core board, and then drilling and through-hole metallization are performed.

‌Graphic production: Use conventional PCB processing technology to make graphics on both sides of the substrate.

‌Solder mask production: Add solder mask and make graphics to expose electrodes and welding areas to improve production efficiency. A substrate usually contains multiple PBGA substrates.

2. ‌BGA area via plugging‌:

The vias in the BGA pad area generally need to be plugged to prevent foreign matter in the hole or to protect the service life of the via, and to prevent the via from tinning during the reflow soldering of the SMT patch, causing a short circuit on the other side.

3. ‌Via in the plate, HDI design‌:

For BGA chips with small pin spacing, when the pin pad cannot be connected due to the process, it is recommended to directly design the via in the plate, and use the HDI blind buried hole wiring method to design the PCB, punch the via in the plate on the BGA pad, punch the buried hole in the inner layer, and conduct the wiring in the inner layer.

4. ‌BGA welding process‌:

‌Printing solder paste‌: Apply an appropriate amount of solder paste evenly on the PCB pad to ensure that the patch components and the corresponding pads on the PCB achieve good electrical connection and sufficient mechanical strength during reflow soldering.

‌Device placement‌: Use a placement machine to accurately mount the chip components to the corresponding position on the PCB surface printed with solder paste or patch glue.

5. Special size design and automated production:

BGA features include high pinhole density, easy automated production, high reliability, and the ability to design special sizes to achieve a more compact chip layout.

What is the difference between PCB and BGA?

The main differences between PCB and BGA are their structure, function, and application scenarios. ‌

1. Structure:

PCB (printed circuit board) is a basic electronic component that provides an electrical connection path between components. BGA (ball grid array package) is an advanced packaging method that connects components to PCB through a spherical pad array, with the advantages of high density and high reliability.

The pins of BGA are spherical and are generally directly soldered on the PCB board. Desoldering requires a special BGA rework station, and individuals cannot desolder; while the pins of PGA (pin grid array package) are pin-shaped. When installing, the PGA can be inserted into a special PGA socket for easy disassembly.

2. Functions and application scenarios:

BGA packaging effectively uses PCB space, which helps save enough space for customization in PCB and improve its efficacy. The size of BGA package is very small, so these PCBs have less heat dissipation and are easy to achieve the dissipation process.

There are no bendable or fragile pins in BGA package, so the durability of these PCBs is increased, and good electrical performance is also ensured. The pads of BGA package are large enough to make it easy to solder and easy to operate, so easy soldering and handling make it very fast to manufacture.

In summary, BGA, as an advanced packaging technology, has been widely used in high-performance electronic products through its unique ball grid array structure and high density and high reliability characteristics. Traditional PCBs provide basic electrical connection paths and are the basic components of electronic devices.

How many types of BGA are there?

There are many types of BGA, mainly including:

1. PBGA (plastic package BGA): This is the most commonly used BGA packaging form, made of plastic materials and plastic processes.

2. CBGA (ceramic BGA): This packaging type uses a multi-layer substrate with precious metal interconnect circuits.

3. CCGA (ceramic solder column array)

4. TBGA (BGA with tape)

5. MBGA (metal BGA)

6. FCBGA (flip chip BGA)

7. EBGA (BGA with heat sink)

In addition, BGA can be divided into staggered type, full array type, and peripheral type according to the arrangement of solder balls.

Conclusion:

Ball grid array (BGA) packaging is a key technology in modern electronic products. It makes it possible to develop more powerful and compact devices. BGA has become the first choice for applications that require high performance, reliability and miniaturization.

BGA packaging is famous for its advanced packaging technology. BEST Technology is recognized as the most trusted one-stop electronic circuit solution provider in the world, and BGA production is one of its most important projects. We specialize in the production and assembly of PCBs containing BGA packaging.

Tags:BGA
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What is the use of relay in power system?

Friday, August 30th, 2024

Relays in power systems are important components that play a vital role in controlling circuits. The core of a relay is an electric switch that can automatically or manually open or close a circuit according to the design. Relays are commonly used in a variety of applications, from small electronic devices to large power systems, and they provide a reliable way to control high-power circuits using low-power signals.

What is relay?

Relay refers to a transfer device in a circuit that controls the switch through the electromagnetic principle to achieve the purpose of automatic control. In power systems, relays can control the switch of circuits by detecting changes in parameters such as current and voltage to achieve protection and control of the system.

What is the use of relay in power system?

The basic working principle of a relay is to use the electromagnetic effect to control the on and off of mechanical contacts. When the coil with an iron core is energized, the coil current generates a magnetic field, which attracts the armature to move, thereby opening and closing the contacts.

Why would you need a relay?

The reasons for needing a relay mainly include safety isolation, remote control, timing or delay control, protection equipment, signal conversion, etc. ‌

1. ‌Safety isolation‌: When a low-voltage device (such as a microcontroller or sensor) is used to control a high-voltage device, the relay can act as an isolation layer to ensure safe operation.

2. ‌Remote control‌: When a device needs to be controlled at a longer distance or in a longer environment, the relay can transmit and amplify the signal to achieve remote control.

3. ‌Timing or delay control‌: When a device needs to be started or shut down at a specific time or after a delay, the relay can achieve timing or delay control.

4. ‌Protective device‌: As a protective device, the relay can prevent the device from being affected by faults such as overload and short circuit.

5. ‌Signal conversion‌: When one signal needs to be converted to another, the relay can perform signal conversion, such as converting an analog signal to a digital signal, or converting a wireless signal to a wired signal.

In addition, relays have the advantages of high reliability, long life, and low power consumption, which can improve the safety and stability of the equipment. Therefore, relays are indispensable and important components in automated control circuits, remote control, telemetry, communication, automatic control, mechatronics and power electronic equipment.

What is the main function of a relay?

The main functions of relays include amplifying signals, realizing remote control, protecting circuits, realizing logical control and improving system reliability and stability. ‌

‌Amplifying signals‌: Relays can convert weak control signals into stronger control signals. Because the contact capacity of relays is large, they can control loads with large currents and high voltages.

‌Remote control‌: Through input signals, relays can control the switch state of load equipment at a distance and realize the function of remote control.

‌Protect circuit‌: Relays have overload protection and short-circuit protection functions. When abnormal conditions occur in the circuit, such as overload, short circuit, etc., the relay can automatically cut off the power supply to prevent the fault from expanding and protect the safety of circuits and equipment.

‌Realize logical control‌: Relays can realize complex logical control through multiple sets of normally open and normally closed contacts, and are widely used in automation control systems, industrial control and other fields.

‌Improve the reliability and stability of the system ‌: Relays have high stability and reliability, which can reduce the failure rate in the system and improve the stability and reliability of the entire system.

In addition, relays also have isolation functions, which can protect the control circuit from the influence of the external environment and prevent electric shock accidents, which is very useful in some occasions with high safety requirements. ‌

What is the difference between a switch and a relay?

Switches and relays have significant differences in function, application, structure and usage scenarios. ‌

1. ‌Function and application‌

Switches are mainly used to connect and disconnect circuits, while relays are mainly used to control the on and off of circuits to achieve protection and control of circuits.

Switches can be regarded as a basic electrical component used to simply connect or disconnect circuits, while relays control the on and off of large currents by controlling small currents in the circuit to achieve remote control or automatic control‌.

2. ‌Structure and design‌

The contacts of switches may be small and are generally used to control small currents. In contrast, the contact switches of relays are larger and can be used to drive larger loads.

Contactors generally have arc extinguishing devices, while relays do not. This shows that relays and switches are different in design and application. Relays are more suitable for use in control circuits, while switches are used in main circuits.

3. Use scenarios

Switches are usually used to directly control the on and off of the main circuit, such as motor start-up, shutdown control, etc. Relays are more used in auxiliary circuits, such as the on and off of the control circuit, or after power is on or off, the on and off of the circuit is controlled by the change of position state, or the output node is given to other circuits.

Although switches and relays both play important roles in electrical systems, they have obvious differences in design, function and purpose. Switches are mainly used for simple circuit on and off operations, while relays are more used for the protection and control of control circuits, controlling the on and off of large currents by small currents, and realizing remote control or automatic control.

What is a relay vs fuse?

Fuses and relays play different roles in automotive circuits and have obvious differences. ‌

‌Fuse‌ is a non-resettable one-time thermal protection device, mainly used for overload protection. When a circuit fails or is abnormal, the current continues to increase. The increased current may damage some important components in the circuit, burn the circuit, or even cause a fire.

The function of the fuse is to disconnect the power supply of the electrical equipment on the vehicle when a short circuit or overload occurs, so as to protect other electrical appliances and lines.

The relay is an automatic control device. When the input (electricity, magnetism, sound, light, heat) reaches a certain value, the output will change in a jump-like manner. Relays are mainly used for overload protection. They control larger currents with smaller currents, and play the role of automatic adjustment, safety protection, and circuit conversion.

The working principle of the relay is to generate a magnetic field through the electromagnet coil, magnetize the iron core, attract it to the magnetic pole of the electromagnet, and then drive the contacts to close or open, so as to realize the switch control of the circuit.

In short, the function of the fuse is to cut off the current automatically when the current abnormally rises to a certain height and heats up, so as to protect the safe operation of the circuit; while the relay protects the circuit and electrical equipment from the influence of overload, short circuit and other faults by controlling the circuit, and at the same time improves the reliability of the circuit operation.

Conclusion:

As technology continues to evolve, relays become more sophisticated and in a world where the demand for power is increasing and the need for reliable power systems is more important than ever, relays will continue to play a vital role in ensuring our power systems remain safe, efficient, and more.

Tags:power supply circuit, relay
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What are the advantages and disadvantages of PCB board?

Friday, August 30th, 2024

PCB is an important component of electronic equipment and comes in many types. Before the advent of printed circuits, electronic components were soldered together by hand, which led to manufacturing errors and resulted in bulky products with complex internal connections due to the large number of wires required.

Developments in printed circuit technology have facilitated more efficient and reliable design and manufacturing of electronic products, allowing for the precise arrangement of electronic components on small, compact circuit boards.

What are the advantages of PCB?

‌Miniaturization and lightweight‌: As consumer electronics products increasingly pursue portability and compact design, thin PCBs have become a key factor in achieving device miniaturization, which can significantly reduce the thickness and weight of the device, making the product more in line with modern aesthetics and use. Habit.

‌Improved heat dissipation performance‌: Thin PCB has a smaller heat capacity, which helps to quickly dissipate the heat generated by electronic components, thus improving the overall heat dissipation efficiency of the device‌.

‌Reduced production costs‌: Thin PCBs require relatively less raw materials during the manufacturing process, and coupled with the possible reduction in the number of assembly layers, the material cost per unit area is reduced.

‌Adapt to high-speed signal transmission‌: Due to its low dielectric loss, thin PCB can effectively reduce signal transmission delay, improve signal integrity, and meet the needs of high-speed data transmission‌.

What are the advantages and disadvantages of PCB board?

‌High-density integration capability‌: PCB multi-layer boards allow for higher-density circuit layouts in a limited space. By arranging conductive paths and components between multiple layers, the size of the circuit board can be greatly reduced and electronic equipment can be improved. overall performance‌.

What are the disadvantages of PCB?

‌Mechanical strength problem‌: The mechanical properties of thin PCB are relatively weak, and it is easy to deform or break due to improper stress during assembly, transportation and even daily use‌.

‌Increased processing difficulty‌: Thin PCBs place higher requirements on the production process. Processes such as drilling, etching, and lamination need to be precisely controlled to prevent problems such as warping and breakage of thin plates‌.

‌Electromagnetic compatibility challenges‌: Thin PCB may increase parasitic capacitance and inductance, affecting the electromagnetic compatibility of the circuit‌.

‌Higher manufacturing costs‌: The manufacturing process of multi-layer boards involves complex processes such as multiple laminations, drilling, and electroplating, resulting in relatively high production costs.

Long production cycle: Due to the complex production process of multi-layer boards, the production cycle is usually longer than that of single-layer or double-layer boards, which may affect the product’s time to market and market competitiveness.

As an indispensable basic material in electronic manufacturing, PCB has the advantages of high reliability, high precision, and small size, but it also has disadvantages such as design and cost restrictions. When choosing to use PCB, you need to comprehensively consider its advantages and disadvantages as well as specific application scenarios.

What are the limitations of PCB?

The limitations of PCB (Printed Circuit Board) mainly include the difficulty of design and manufacturing, complex testing and troubleshooting, and environmental impact. ‌

‌Design and manufacturing are difficult‌: Designing multi-layer PCBs requires highly specialized knowledge and software tools to ensure signal integrity and optimization of power distribution.

‌Complex testing and troubleshooting‌: Due to the complexity of the multi-layer structure, once a failure occurs, it becomes more difficult and time-consuming to locate and repair the problem.

‌Environmental impact‌: Special chemicals and precious metals may be used in the production process of high-end multi-layer PCBs. If not handled properly, they may have a certain impact on the environment.

These limitations have put forward higher requirements for the design, manufacturing, testing and use environment of PCB, which require comprehensive consideration and optimization in terms of technology, cost, environmental protection and other aspects.

Why do PCB boards fail?

1. ‌Improper design‌

Including unreasonable PCB board design, improper part orientation design, automatic plug-in bent legs, etc. These problems may lead to short circuit faults, and the part orientation or design needs to be modified to avoid short circuits.

2. ‌Poor manufacturing‌

Problems during the manufacturing process, such as solder joint problems, damaged pads, improper installation of components, etc. These problems will affect the reliability of the welding and cause the circuit board to deform or crack.

3. Poor usage environment

PCB boards are affected by the environment, such as extreme temperature changes, excessive humidity, high-intensity vibration, etc., which may cause damage to the PCB board and affect its performance and reliability.

4. ‌Other reasons

It also includes circuit board aging, design defects, manufacturing process problems, etc., such as metal components on the circuit board reacting with oxygen, causing oxidation, or assembly deviations during the manufacturing process causing component position deviation, etc.

What can damage a PCB?

Factors that damage PCB (Printed Circuit Board) mainly include physical damage, chemical corrosion, electrochemical corrosion, electrostatic discharge, humidity and moisture, temperature changes, etc. ‌

1. ‌Physical damage‌: including vibration, falling, hitting, and stacking, which may cause PCB deformation and cracks, leading to circuit breakage or short circuit‌.

2. Chemical corrosion: The PCB surface may be exposed to chemicals, such as acids, alkalis or other corrosive solutions, causing corrosion.

3. ‌Electrochemical corrosion‌: When there is a potential difference between different metal components, a battery is formed in a humid environment, which accelerates the corrosion of one of the metals. This is called electrochemical corrosion‌.

4. ‌Electrostatic discharge‌: Electrostatic discharge is the invisible killer of PCB. It can generate thousands of volts in an instant, which is enough to damage the components on the PCB‌.

5. Humidity and moisture: Extreme temperatures or temperature changes, as well as moisture in the air, can cause PCB board damage, such as deformation, short circuit, corrosion and other problems.

6. ‌Temperature changes‌: Temperature changes can also cause solder joints, substrate materials and even casings to crack. If the circuit is going to be exposed to high temperatures, you may need to choose components that can withstand higher temperatures‌.

What is the lifespan of a PCB?

There is no fixed international standard for the service life of PCB, and its specific life span depends on many factors. ‌

‌Materials and manufacturing processes‌: The materials and manufacturing processes of the PCB board have a decisive impact on its service life. PCB boards made of different materials and processes have different service lives.

‌Normal use and maintenance‌: Under normal use and no damage, the life of the circuit board itself is quite long. Manufacturers usually give a lifespan indicator of about 5 years, but this does not mean that the circuit board cannot be used after 5 years. In fact, as long as a circuit board is properly maintained and maintained, it can last for decades‌.

‌Lifetime under specific conditions‌: For PCBs containing OSP parts, the vacuum seal is valid for up to 3 months. For non-OSP PCBs, if the storage period exceeds 6 months but is less than one year, the chip factory will bake them before producing them; if the storage period exceeds one year, they will be scrapped. Boards opened during production should be used within 24 hours.

The service life of PCB is not a fixed value, but depends on the specific situation. With proper design, manufacturing, use and maintenance, the life of a PCB can be significantly extended‌.

What are the dangers of PCB?

The wastewater generated during the PCB manufacturing process contains heavy metals (such as copper, nickel, lead, etc.) and organic matter. If these pollutants are discharged without proper treatment, they will cause serious pollution to the environment.

In electronic products, common defects in PCB boards include open circuits, short circuits, false soldering, solder beads, and substrate warping. These defects can cause electronic products to fail to work properly or even fail completely.

PCB circuit boards play a vital role in the manufacture of modern electronic devices. They are widely adopted for their high reliability, compactness, and high scalability. When choosing to use PCB circuit boards, you need to consider their advantages and disadvantages and make a wise decision based on the needs of the specific project.

BEST Technology has been deeply involved in the circuit board industry for many years and has many solutions for various PCB problems. You can find us for all your PCB problems.

Tags:PCB, PCBA
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What is solder paste? What is its function?

Thursday, August 29th, 2024

What is the role of solder paste? Electronic devices have been deeply integrated into our daily lives. Whether it is mobile phones, tablets or household appliances, they are inseparable from electronic components. How are these components accurately soldered to the circuit board? The answer lies in surface mount technology (SMT) and the important material it uses – solder paste.

In the process of SMT patch processing, solder paste is an indispensable and important material. The quality and use method of solder paste directly affect the welding effect and the performance of the final product.

What is the composition of solder paste?

Solder paste is a complex mixture of multiple components, and its main components include metal powder, flux and solvent.

What is solder paste? What is its function?

The metal powder in solder paste is usually composed of metal alloys such as tin, silver and copper. The particle size and distribution of metal powder have a direct impact on the welding effect. The smaller the particle size, the more uniform the distribution, and the better the welding effect.

At the same time, the composition of the metal alloy also determines the mechanical strength and electrical properties of the solder joint.

Flux is another important component in solder paste. Its main function is to remove oxides on the welding surface and improve the wettability and reliability of welding.

The type and formula of flux directly affect the melting state and solder joint quality during the welding process. Common fluxes include rosin-based flux, organic acid flux and halogen-free flux.

Solvents are used to adjust the viscosity and printing performance of solder paste. Appropriate viscosity can ensure that the solder paste is evenly distributed during the printing process without problems such as drawing and collapse. The evaporation rate of the solvent will also affect the drying time and welding performance of the solder paste.

What is the role of solder paste in SMT patches?

In the SMT (surface mount technology) patch processing process, solder paste plays a vital role. It is not only used to bond components, but also the key to ensure the quality of electrical connections and mechanical strength.

1. Bonding components

One of the main functions of solder paste is to bond components. After the solder paste is accurately printed on the pads of the PCB (printed circuit board), the pins or contact points of the electronic components will be placed on the solder paste. The solder paste melts during the reflow soldering process to form a strong bond, ensuring that the components are stably attached to the PCB.

2. Provide electrical connection

Solder paste melts during the reflow soldering process and forms metal solder joints, which not only bond components but also provide electrical connections. Good electrical connections ensure the effective transmission of electrical signals on the PCB, which is the basis for ensuring the normal operation of electronic equipment.

The solder joints formed by the metal components (such as tin, silver, and copper) in the solder paste after melting have excellent conductivity, ensuring the reliability and stability of electrical connections.

3. Ensure mechanical strength

The mechanical strength of the solder joints is the key to ensuring the stable operation of electronic components in various environments. The solder joints formed by the solder paste after reflow soldering have sufficient mechanical strength to resist external stresses such as vibration, impact, and thermal expansion and contraction. This not only protects the components and PCB, but also improves the reliability and service life of the entire electronic equipment.

Is solder paste the same as flux?

Solder paste and flux are not the same. ‌

Although both solder paste and flux are materials used in the welding process, their functions and uses are different.

Solder paste is a paste-like viscous body, the main components of which include metal powder, rosin, organic acid, thixotropic agent, and activator, and is used for welding in SMT automatic mounting process.

Flux is a liquid, a mixture with rosin as the main component, which is used to remove oxides on the surface of solder and the base material to be welded, so that the metal surface reaches the necessary cleanliness, prevents the surface from re-oxidation during welding, reduces the surface tension of the solder, and improves welding performance.

In general, although both solder paste and flux are indispensable materials in the welding process, they have obvious differences in form, function, and usage.‌

What is the storage method of solder paste?

The correct storage method can extend the service life of the solder paste and ensure its stable performance.

1. Temperature control

Solder paste should be stored in a low temperature environment, usually 0-10℃. Excessive temperature will cause the solvent in the solder paste to volatilize, affecting its viscosity and printing performance. Avoid direct sunlight and high temperature environment during storage to prevent the solder paste from deteriorating.

2. Humidity control

Humidity has a great impact on solder paste. Excessive humidity will cause the solder paste to absorb moisture, affecting its printing performance and welding quality. The relative humidity of the storage environment should be controlled below 50% to ensure the stability of the solder paste.

3. Sealed storage

The solder paste should be stored in a sealed container to prevent oxygen and moisture from entering the air. The solder paste after opening should be used up as soon as possible, and the unused solder paste should be resealed and stored in a low temperature environment.

How to use solder paste correctly?

1. Reheating treatment

The solder paste stored in a low temperature environment should be reheated before use. The reheating time is usually 4-8 hours. During the reheating process, it should be avoided to be directly exposed to a high temperature environment to prevent the solvent in the solder paste from volatilizing. The solder paste after reheating should be fully stirred to ensure that the metal powder and flux are evenly distributed.

2. Printing process

Solder paste printing is a key process in SMT patch processing. During the printing process, the scraper pressure, printing speed and template opening size should be controlled to ensure that the solder paste is evenly distributed on the pad. The printed solder paste should have a good shape and should not have problems such as drawing and collapse.

3. Solder paste reflow

The solder paste reflow process is the process of melting the solder paste and forming a firm solder joint with the pad and component pin. The temperature curve should be controlled during the reflow soldering process to ensure that the solder paste melts at an appropriate temperature and fully wets the pad and pin. Too high or too low reflow temperature will affect the welding quality.

4. Solder joint detection

The quality of the solder joint is an important indicator for evaluating the welding effect. After the welding is completed, the solder joint detection should be carried out to check the shape, size and wettability of the solder joint. Qualified solder joints should have a smooth and complete surface without defects such as solder balls and cold solder joints.

Conclusion:

Solder paste plays a vital role in SMT patch processing. Its composition, selection, storage and use methods directly affect the welding quality and the performance of the final product. By understanding and mastering the relevant knowledge of solder paste, the quality of SMT patch processing can be effectively improved, and defects and rework rates can be reduced.

BEST Technology has rich experience and strict control standards in the selection and use of solder paste, and can provide customers with high-quality SMT patch processing services. If you have any questions about our products or services, please feel free to contact us. Choose BEST Technology , choose quality assurance.

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What is a resistor? Does it have polarity?

Wednesday, August 28th, 2024

In circuits, resistor act as voltage dividers. When different voltage levels need to be obtained from a power supply, voltage distribution can be achieved by connecting resistors in series. Specifically, the magnitude of the voltage will be distributed in proportion to the magnitude of the resistors. And resistors have no polarity. Resistors are passive electronic components. Their purpose is to provide fixed or variable resistance to the flow of current, regardless of the direction of the current.

What is a resistor?

A resistor is a current-limiting element that is used to limit the magnitude of the current through the branch to which it is connected. ‌

Resistors are a basic electronic component whose function is to hinder the flow of current. The resistance value of a resistor is fixed and generally consists of two pins. It is used to divide voltage, adjust signals, stabilize and adjust current and voltage in circuits.

Depending on whether the resistance value is variable, resistors can be divided into fixed resistors and variable resistors (potentiometers). The resistance value of a fixed resistor cannot be changed, while the resistance value of a variable resistor can be changed by adjusting the contact position. An ideal resistor is linear, that is, the instantaneous current through the resistor is proportional to the applied instantaneous voltage.

Resistors play an important role in circuits, whether as voltage dividers, current limiters, or in regulating the voltage and current in circuits.

How to identify resistor polarity?

Resistors are generally non-polar. Resistors are mainly used in circuits to limit current, divide voltage, shunt, etc. Their physical properties are completely determined by the materials used inside. Their main functions are voltage division, current shunting, current limiting, voltage reduction, impedance matching, etc. They do not care about how they are placed, so any type of basic resistor is non-polar.

Although in electrical analysis, people may assume that resistors have polarity to more intuitively understand the flow of current, this does not mean that resistors themselves have polarity. In fact, resistors can be regarded as a kind of extremely powerful wire with a specific power rating and resistance, and its function is to hinder or reduce current in both directions.

When identifying resistors, it is usually not necessary to consider their polarity because resistors do not have a fixed positive or negative pole. If you need to determine the direction of the current, you can judge it by the circuit symbol or other identification, but this has nothing to do with the polarity of the resistor itself.

Do any resistors have polarity?

Not all resistors have polarity. ‌

A resistor is an electronic component whose main function is to block the flow of electric current. In most cases, resistors themselves have no polarity, which means that both ends of the resistor can be considered as positive or negative potential. There are many types of resistors, including fixed resistors, adjustable resistors, and various sensitive resistors, but they do not have positive and negative polarity.

However, there are some special types of resistors, such as type A in the resistor array, which are polarized. But this does not mean that all resistors have polarity, because most resistors are non-polar. For example, type B in the resistor array has no polarity, and other types of resistors (such as C, D, E, F, etc.) have different internal resistor arrangements, but because they are not often used, the resistors usually referred to are generally non-polarized. ‌

In summary, although there are some special types of resistors that may have polarity, in most cases, resistors are electronic components without polarity. ‌

Do resistors have a positive and negative side?

Resistors have no positive and negative poles. ‌Resistors are passive electronic components whose main function is to block the flow of electric current without caring about the direction of the current. In the circuit, the direction of the current is indicated by an arrow, and the resistor itself does not change its impedance characteristics due to the change of the current direction.

Whether it is a fixed resistor, an adjustable resistor or a sensitive resistor, there is no distinction between positive and negative polarity. In AC circuits, there is no need to distinguish between positive and negative poles. In DC circuits, although the variable resistor is composed of a carbon film and a metal contact, it is necessary to clarify the direction of the current, but this does not mean that the resistor itself has positive and negative poles, but it means that the direction of the current needs to be clarified in DC circuits.

The concept of positive and negative poles is usually used for power supplies, batteries and certain specific components, where the positive pole is usually connected to a high potential and the negative pole is connected to a low potential. Power supplies and batteries have a positive and negative pole because of the potential difference, while resistors, as a passive component, have no potential difference, so there is no distinction between positive and negative poles.

In a circuit, when the power supply is connected, the current flows out from the positive pole, passes through the resistor, and finally returns to the negative pole, forming a current cycle, but this does not change the nature of the resistor itself, but is only part of the current path.

Can a resistor be connected in any direction?

Resistors can be connected in any direction. ‌Resistors are passive devices that do not distinguish polarity, so they can be installed at will without affecting their normal operation.

This characteristic of resistors makes the connection direction of resistors in the circuit very flexible. In addition, the connection direction of resistors is not affected by the direction of current, and even if the current direction changes, the performance and resistance of resistors will not change. Therefore, in practical applications, the connection direction of resistors can be freely selected as needed to meet specific circuit requirements.

Is there a wrong way to install a resistor?

If the welding is not firm or there are problems such as cold welding and short circuit, the resistor will lose connection or become abnormal, which will cause the circuit to work abnormally.

When installing the ground wire, if the grounding resistor is not installed correctly, and the appropriate time and conditions are not selected when measuring the grounding resistance, or the connection wire with the equipment is not disconnected when measuring the protective grounding resistance of the electrical equipment, the measurement results may be inaccurate.

In order to avoid these errors, it is very important to install and test the resistor correctly. When installing the resistor, ensure the welding quality, correctly measure the grounding resistance, and follow the correct installation steps and testing methods to ensure that the resistor can work properly.

How to wire a resistor to an LED?

When connecting a resistor to an LED, the resistor can be connected to the positive or negative terminal of the LED, as long as the polarity of the power supply is connected correctly. ‌

When using a resistor with an LED, the main function of the resistor is to limit the current to protect the LED from excessive current damage. Whether the resistor is connected to the positive or negative terminal of the LED, the key is to ensure that the current limit of the entire circuit is within the range that both the LED and the resistor can safely withstand. Specifically:

‌Connected to the positive terminal of the LED‌: In this configuration, the resistor is connected to the positive terminal of the LED, and the voltage applied to the two terminals of the LED is limited by controlling the current flowing through the resistor, thereby protecting the LED. This configuration is suitable for a variety of power supply voltages and LED types. As long as the polarity of the power supply is connected correctly, the position of the resistor (positive or negative) has little effect on the normal operation of the LED.

‌Connected to the negative terminal of the LED‌: Connecting the resistor to the negative terminal of the LED can also achieve the purpose of current limiting. This configuration also requires that the polarity of the power supply is connected correctly to ensure the safety of the circuit and the normal operation of the LED.

In practical applications, if you encounter the problem of frequent LED damage, it may be due to the quality problem of the LED itself or the circuit design defect.

In short, when connecting a resistor to an LED, the key is to ensure the safety of the entire circuit and the normal operation of the LED. By correctly selecting the position and value of the resistor and ensuring that the polarity of the power supply is correctly connected, the LED can be effectively protected from damage.

Conclusion:

Resistors play a vital role in circuits. They can protect various components of the circuit by controlling the magnitude of the current. With the evolution of products, various types of resistors have been generated, which can change their resistance values according to changes in the environment. Therefore, resistors are still very important until now. Understanding the role and use of resistors will help us understand circuits.

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What is PCB test and What is Tested?

Wednesday, August 28th, 2024

PCB test is a method of performing operational and functional tests on a circuit board and layout optimization. PCB test identifies any shorts, opens, incorrect component placement, or faulty components.

The purpose of PCB test and inspection is to check if the PCB meets the performance of a standard printed circuit board. It ensures that all PCB manufacturing processes are operating properly and without any defects as per the project specifications.

A PCB consists of different elements and components, each of which affects the overall performance of the electronic circuit. These components are analyzed in detail to ensure the quality of the PCB.

What is a PCB test?

PCB test is a technique that uses electronic testing instruments to detect the performance and quality of PCB (Printed Circuit Board) circuit boards. It is widely used in the electronics manufacturing industry to help manufacturers improve product quality and production efficiency.

The main purpose of PCB test is to ensure that all parts on the circuit board are properly connected and can still work properly under high voltage environments, while verifying whether the function of the circuit board is normal. Test methods include connectivity testing, withstand voltage testing, and functional testing, while inspection standards involve appearance inspection, size inspection, and performance inspection. In addition, PCB test also involves a series of professional techniques and methods, such as flying probe test, ICT test, FCT test, AOI test, etc., to ensure the electrical performance and structural integrity of the circuit board.

How to Test PCB?

PCB contains different components that affect the overall performance of electronic circuits. Tests are performed to check and optimize the status of these components using computerized machine software, simple electronic test equipment and tools, and even basic manual inspections.

1. Electrical test

2. Hole wall quality

3. Mechanical resistance test

4. Soldering quality

5. Cleanliness inspection, considering weather resistance, humidity and corrosion

6. Lamination, testing the ability of laminates to resist or heat peeling

Environmental testing is particularly necessary for PCBs used in humid environments.

What are the benefits of PCB test?

Error identification: The main benefit of PCB test is that it helps identify problems in PCBs. Whether the problem lies in functionality, manufacturability or other aspects, PCB test can identify problems in PCB design and layout.

Save time: Performing PCB test early helps save time in the long run by allowing designers to identify major issues during the prototyping phase. Comprehensive testing allows designers to quickly and easily identify the root cause of each issue and make adjustments so that they can move to production at a faster pace and reduce product lead times.

Reduce costs: PCB test avoids the waste of producing defective products by testing products using prototypes and small-scale components. By completing comprehensive testing early in the design process, designers can avoid the waste of producing defective PCBs, ensuring that the design is as perfect as possible before going into production.

Reduced returns: When PCB test is performed, the likelihood of selling defective products or products that do not meet performance standards is reduced, reducing the costs associated with refunding customers and handling defective goods.

Improved safety: Defective PCBs can cause fires, which can endanger people nearby. Pre-manufacturing testing also ensures that machines and workers are not damaged or injured due to poor design during the production process.

What are the types of PCB test?

1. In-circuit testing

In-circuit testing (ICT) is the most reliable type of PCB test available today. The high price reflects this – tens of thousands of dollars, although the cost depends on factors such as board and fixture size.

Also known as bed of nails testing, ICT fires and activates individual circuits on a board. In most cases, the test is designed to achieve 100% coverage, but actual coverage will be closer to 85-90%.

The test involves the use of fixed probes, whose layout matches the PCB design. The probes check the integrity of the soldered connections. A bed of nails tester simply pushes the board onto the probe bed to begin testing. Access points are pre-designed on the board to allow the ICT test probes to establish a connection with the circuit.

2. Flying probe testing

Flying probe testing is a tried and tested method that is cheaper than in-circuit testing. It is a non-powered test that checks for shorts, capacitance, inductance, diodes, and other problems.

The flying probe tester works by using needles connected to probes on an xy grid obtained from basic CAD. The ECM program coordinates to match the board and then runs the program connected to these test points.

In some cases, ICT makes flying probe testing unnecessary, but the PCB must be designed to fit the test fixture – which means a higher initial cost. ICT is faster and less error-prone than flying probe testing, and while flying probe testing may be cheaper initially, it may not actually be cost-effective for large orders. Finally, it is important to note that PCB flying probe testing does not power the board.

3. Automated Optical Inspection (AOl)

AOI is a contact-free visual inspection of printed circuit boards. AOI uses a camera and microscope to take photos of the PCB. The software then looks for inconsistencies between these photos and the board schematic. Technicians can thoroughly check each board and find any problems through this procedure.

The board is not powered during AOI, and it may not cover all part types. Due to these deficiencies, it should be used in conjunction with another test technology such as functional testing, flying probe testing, or ICT.

4. X-ray Inspection

As the name suggests, this type of test is essentially an inspection tool. It is also known as AXI. During this testing, X-ray technicians can detect defects early in the production process by carefully inspecting solder connections, internal traces, and barrels. Using X-ray inspection, invisible components can be inspected.

Due to the high density of SMT technology and the difficulty in locating connections in BGA and CSP (chip scale packages), more precise inspection techniques, such as those based on X-ray technology, are needed. Solder joints can be clearly seen in radiographs because they are made of materials with a higher atomic weight than other components on the board.

The main benefit of AXI technology is that it can identify every connection and solder joint, including those hidden by the package. In addition, solder joints can be inspected, highlighting any potential bubbles.

What are the difficulties in PCB test?

Increasing complexity: PCB designs are becoming more complex, with higher component density and smaller size, which makes it more difficult to access test points and increases the risk of undetected defects.

Cost: High-end test equipment such as X-ray inspection systems can be expensive to purchase and maintain. Testing also increases production costs, especially when test failures require rework.

Accuracy: Although the test equipment is designed precisely, errors may still occur due to calibration problems, software errors or human errors.

Conclusion:

PCB test is very important to the quality of the product. It ensures that the PCB, which forms the backbone of all electronic devices, operates normally and meets the required quality standards, effectively avoiding the impact of poor products, improving the quality of the finished product, and preventing problems when the product is used.

BEST Technology has a complete set of PCB test equipment and has very complete testing standards to ensure that each PCB finished product has extremely high quality. Choosing us, you will not need to worry about any PCB quality issues.

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How to use solder flux?

Tuesday, August 27th, 2024

In the manufacturing process of printed circuit boards, it is very necessary to apply a proper amount of flux. The soldering pads, copper bars of components and the surface of solder paste are the places where flux should be applied, which can improve the firmness of the soldering points and the quality of printed circuit boards.

What is flux?

Flux: A chemical substance that can help and promote the soldering process in the soldering process, and at the same time has a protective effect and prevents oxidation reactions. Flux can be divided into solid, liquid and gas.

There are mainly several aspects such as “assisting heat conduction”, “removing oxides”, “reducing the surface tension of the material to be soldered”, “removing oil stains on the surface of the material to be soldered, increasing the soldering area”, and “preventing re-oxidation”. Among these aspects, the two most critical functions are: “removing oxides” and “reducing the surface tension of the material to be soldered”.

Do you apply flux before or after soldering?

Use flux before soldering printed circuit boards. ‌

During the soldering process of printed circuit boards, the main purpose of using flux is to improve soldering performance and help the metal avoid the formation of an oxide film that hinders solder wetting when heated, thereby promoting the formation of solder-metal alloys and avoiding the occurrence of cold soldering and false soldering.

Flux can be applied to the printed circuit board before soldering, or it can be used as part of the solder during the soldering process, such as solder paste or solder oil. When tinning the pins of components, rosin should be used as the flux, and if the printed circuit board is already coated with rosin solution, then no additional flux is required during soldering.

After using flux, make sure to wipe off the residual flux at the soldering site after soldering to avoid potential damage to electronic components and circuit boards.

In addition, the preparation work before soldering includes thoroughly cleaning the copper foil surface and then applying rosin water to protect the copper foil and help soldering. This step is performed before soldering to ensure the smooth progress of the soldering process. Therefore, the correct approach is to use flux before soldering printed circuit boards to ensure the quality and reliability of soldering.

How much flux to use when soldering?

When soldering printed circuit boards, the amount of flux used needs to be determined according to the specific soldering method and the type of flux. For wave soldering flux, when using brushing and foaming methods, the specific gravity of the flux should be controlled between 0.82-0.84 (specific gravity of liquid rosin flux stock solution).

During the soldering process, the specific gravity of the flux needs to be measured regularly. If the specific gravity is found to increase, it should be adjusted to the normal range with diluent in time, but the diluent should not be added too much to avoid affecting the soldering quality.

For the quantitative spraying method, the key is that the nozzle can control the spray volume. The nozzle should be cleaned frequently to ensure that the spray hole is not blocked. The spray pressure should be controlled at 0.2-0.3Mpa, the flux pressure should be controlled at 0.4±0.05Mpa, and the spray flow rate should be controlled at 20-35ml/min.

In addition, different types of flux formulas are also different. For example, rosin liquid can be made by mixing rosin blocks and alcohol in a ratio of 1:3. For the flux of printed circuit boards, you can directly use rosin water, and apply the prepared rosin water directly on the surface of the printed circuit board or the solder joints.

When using flux, you should also pay attention to the following points:

Put the bottle cap on immediately after use to prevent the flux from being in contact with air for a long time and causing oxidation reaction or absorbing water vapor in the air to cause the concentration to decrease.

Regularly replace the flux that has been stored for too long, because long-term storage will cause the flux composition to change and the activation performance to deteriorate, affecting the welding quality.

Clean it after welding, because the insulation performance of the flux will drop sharply at high temperature, and the residue may affect the heating components, and in severe cases may cause short circuits.

In summary, the amount of flux used in printed circuit board welding needs to be determined according to the specific welding method and flux type, and pay attention to the use and storage conditions of the flux to ensure welding quality and safety.

What happens if you use too much flux when soldering?

First, the main functions of flux include assisting heat conduction, removing oxides, reducing the surface tension of the material being soldered, removing oil stains on the surface of the material being soldered, increasing the soldering area, and preventing reoxidation.

However, excessive use of flux can lead to corrosion and electromigration. This is because improper use of flux, such as excessive use, can create more favorable conditions for potential chemical corrosion reactions.

In addition, if the flux used is not well controlled, resulting in excessive use of flux, more flux residue will be left, which creates more favorable conditions for potential chemical corrosion reactions.

Therefore, it is very important to control the amount of flux used to avoid negative effects on soldering quality and reliability.

What happens if I don’t use flux?

If flux is not used on printed circuit boards, it may lead to reduced soldering quality, increased soldering difficulty, and affect the performance and reliability of the circuit.

1. Increased soldering difficulty: Without flux, the solder may be difficult to flow to the soldering point, resulting in loose soldering, prone to cold soldering or poor soldering.

2. Reduce welding quality: Without the help of flux, the soldering point may not be smooth enough, with burrs or unevenness, which may affect the normal operation of the circuit.

3. Affect circuit performance and reliability: Flux can reduce the resistance of the soldering point and improve the conductivity of the circuit. Without flux, the resistance of the soldering point may increase, affecting the performance and stability of the circuit.

In addition, the flux can also prevent oxidation to a certain extent, protect the soldering point from the influence of the external environment, thereby improving the life of the circuit. Therefore, in the soldering process of printed circuit boards, it is very important to use the soldering flux correctly.

What is an alternative to soldering flux?

Alternatives to printed circuit board soldering flux include no-clean soldering flux, special solder resist for printed circuit boards, water-based cleaning agents and dry ice cleaning technology. ‌

1. No-clean soldering flux is a new type of soldering flux that does not contain halide activators. It does not need to be cleaned after use, which can save investment in cleaning equipment and cleaning solvents, while reducing the emission of waste gas and wastewater, and the pollution to the environment is also reduced accordingly.

2. The main function of the ‌PCB solder mask‌ is to prevent “wiring” and short circuits during wave soldering and protect the PCB permanently. In addition, it can save solder, reduce the weight of the PCB, and reduce costs.

3. As a new type of cleaning medium, the ‌water-based cleaning agent‌ achieves cleaning through the wetting, dissolution, emulsification, saponification, chelation and other effects of the surfactants, emulsifiers, penetrants, etc.

4. The ‌dry ice cleaning technology‌ uses extremely low-temperature dry ice particles to spray onto the treated object under the action of compressed air, so that the dirt is rapidly frozen to brittleness and burst, and then vaporized to take away the dirt.

These substitutes have their own characteristics and are suitable for different application scenarios and technical requirements. When choosing, specific process requirements and cost-effectiveness must be considered.

What does rosin do when soldering?

In the process of printed circuit board soldering, rosin plays a vital role. It is mainly used as a flux to help the soldering process be smoother and more efficient. The role of rosin is reflected in the following aspects:

‌Removing oxide film‌: Rosin can remove the oxide film formed on the copper surface due to contact with air. These oxide films will prevent the tin from wetting the copper wire, thus affecting the quality of welding.

‌Preventing re-oxidation‌: Rosin can not only remove the oxide film, but also prevent the soldering surface from re-oxidizing during the welding process, which helps to maintain the stability and reliability of the welding point.

‌Isolating air‌: Under high temperature conditions of welding, rosin can isolate the air and prevent oxidation of the metal surface.

In summary, rosin plays an important role in the soldering process of printed circuit boards. Through its fluxing effect, it improves the quality and reliability of soldering and is one of the indispensable materials in electronic manufacturing‌.

Conclusion:

Flux is a key part of the soldering process. Without it, your solder will not flow smoothly through the joint and the solder will not adhere properly to the various components on the circuit board. High-quality flux is necessary to produce good solder joints.

BEST Technology is a professional PCB circuit board manufacturer with many years of experience in PCB circuit board welding. The circuit boards it produces are of extremely high quality. We have the most extensive experience to deal with all aspects of PCB welding issues.

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What are the types of PCB boards?

Monday, August 26th, 2024

PCB (Printed Circuit Board) boards can be classified according to their constituent materials and characteristics. PCBs are classified into single-sided boards, double-sided boards, and multi-layer boards according to board applications. They are classified into flexible PCB boards (flexible boards), rigid PCB boards, rigid-flexible PCB boards (rigid-flexible boards) according to materials, etc.

PCB is an important electronic component, a support for electronic components, and a provider of electrical connections for electronic components. Since it is made using electronic printing technology, it is also called a printed circuit board. PCB is simply a thin board with integrated circuits and other electronic components.

1. Single-sided board:

On the most basic printed circuit board, parts are concentrated on one side and wires are concentrated on the other side. Because wires only appear on one side, this type of printed circuit board is called a single-sided board. Because single-sided boards have many strict restrictions on designing circuits (because there is only one side, wiring cannot cross and must go around a separate path), early circuits used this type of circuit board.

2. Double-sided board

This type of circuit board has wiring on both sides. In order to connect the wires on both sides, there must be a proper circuit connection between the two sides. This connection between the circuits is called a guide hole. A guide hole is a small hole filled or coated with metal on a printed circuit board, which can be connected to the wires on both sides. Because the area of a double-sided board is doubled that of a single-sided board, and the wiring can be interlaced (can go around to the other side), double-sided boards can be used on more complex circuits than single-sided boards.

3. Multilayer board:

In order to increase the area that can be wired, multilayer boards use more single- or double-sided wiring boards. Multilayer boards use several double-sided boards, and put an insulating layer between each layer of boards and glue them firmly. The number of layers of the circuit board represents how many independent wiring layers there are, usually an even number of layers, and includes the two outermost layers.

4. Flexible PCB board

Flexible PCB board is a printed circuit board made of a flexible substrate. Its advantage is that it can be bent, which is convenient for the assembly of electrical components. Flexible circuit board, flexible PCB, flexible circuit and multi-function printed circuit are other names for these circuit boards. These printed circuit boards are made using the same components as rigid printed circuit boards. The main difference is that the circuit board is designed to bend to the desired shape throughout the application process. These PCBs are available in single-sided, double-sided, and multi-layer configurations. This helps reduce the complexity of unit assembly.

5. Rigid PCB Board

Rigid PCB is a circuit board that cannot be twisted or folded. The base material of the board is a rigid substrate, which gives the board rigidity and strength. They are composed of multiple layers, including substrate layers, copper layers, solder mask layers, and silk screen layers, which are bonded together by adhesives and heat. While some circuit boards are single-sided, double-sided, or multi-layered, rigid PCBs can be any of these as needed. However, once made, they cannot be modified or changed.

6. Rigid-Flex Board

Rigid-Flex Board is a hybrid circuit board that combines elements of flexible and rigid circuit boards to form a foldable or continuously bendable circuit board, which is usually molded into a curved shape or curve during the manufacturing process.

The flexible portion of the circuit board is often used for interconnections between rigid circuit boards, allowing narrower wires to take up less space, thereby reducing the size of the circuit board. Using flexible PCBs for interconnections often eliminates the need for bulky and heavy connectors, making rigid-flex boards lighter. The design of rigid-flex boards is slightly more complicated because these boards are 3D constructed, allowing the board to be folded or twisted to produce the shape required for the product.

7. High-frequency PCB board

High-frequency circuits refer to the overall circuit board design, not the other types of circuit board structures we described earlier. These PCBs are designed to conduct signals over 1 GHz.

High-frequency boards mostly use FR4-grade glass-reinforced epoxy boards, polyphenylene ether (PPO) resins, and Teflon, but Teflon has a low and stable Dk value, low dielectric loss, low hygroscopicity, and is slightly more expensive.

When designing high-frequency circuits, various factors must be considered, such as Dk value, dissipative loss, and dielectric thickness. The DK value of the substrate is an important factor to remember. Substrates with a higher probability of Dk value changes usually experience impedance changes, which affects the harmonics that make up the electrical signal, resulting in poor signal integrity.

8. Copper substrate

Copper substrate is a metal substrate with high thermal conductivity, suitable for high-frequency circuits and areas with large high and low temperature changes and heat dissipation and architectural decoration industries for precision communication equipment.

The copper substrate circuit layer requires a large current carrying capacity, and a thicker copper foil should be used, with a thickness of generally 35μm~280μm. The thermal conductive insulation layer is the core technology of the copper substrate. It is composed of core thermal conductive components and high molecular polymers, with low thermal resistance (0.15), excellent viscoelastic properties, resistance to thermal aging, and the ability to withstand mechanical and thermal stress.

The copper substrate metal base is the supporting member of the copper substrate, which is required to have high thermal conductivity. It is generally a copper plate, and a copper plate can also be used (where the copper plate can provide better thermal conductivity). It is suitable for conventional mechanical processing such as drilling, punching and cutting.

9. Aluminum-based PCB board

The design of aluminum-based PCB circuits is similar to that of copper-based PCBs, but the substrate material of aluminum-based PCBs is aluminum metal, rather than the standard glass fiber used in most circuits.

The aluminum layer is reinforced with the least heat-resistant insulation material, which means less heat is transferred from the insulation material to the backing. After applying the insulation layer, another layer of copper is required.

10. High Density Interconnect (HDI) PCB

Among the many types of PCBs, HDI PCB is a circuit with multiple interconnections that takes up very little space. HDI components are mounted close to each other, minimizing PCB space while maintaining high functionality. Boards containing 120-160 pins per square inch are classified as HDI PCBs.

HDI designs integrate dense device mounting and multi-purpose wiring. With the help of microvias, buried vias, and blind vias, compact circuits can be made, minimizing drilling to copper. For the electrical requirements of high-speed signals, HDI PCBs must have high-frequency conduction capabilities, impedance control, and minimal redundant radiation.

11. Thick Copper PCB

Thick copper PCB is also called heavy copper PCB. Basically, it contains more than 2 ounces of copper in the inner and outer layers of the board. Heavy copper transmitters significantly increase the overall thickness of the board; thick copper boards are known for supporting high currents, high temperatures, and cyclical thermal cycles.

12. High TG PCB

Among various types of PCBs, high Tg PCBs are circuit boards designed to work at high temperatures. Glass transition temperature (Tg) is an essential element of any epoxy resin. It is basically the temperature point at which the polymer changes from a hard glass substrate to a soft rubber substrate. The substrates used to make high Tg circuit boards must be flame retardant, which means that they soften instead of burning at the glass transition point (Tg).

The higher the Tg value, the higher the temperature requirement during lamination. Under such conditions, the PCB will become hard and brittle, affecting the aperture size and related electrical properties. Standard boards will soften, deform and melt under such conditions, and their mechanical and electrical properties will be significantly reduced.

Standard FR-4 Tg is between 130-1400C, medium Tg is between 150-1600C, and high Tg is above 1700C. The higher the Tg value, the better the board’s heat, moisture and chemical resistance.

Conclusion:

PCB board types are updated and iterated with the rapid development of the industry, and various types of PCB boards have gradually evolved to cope with various application scenarios, adding corresponding materials according to the required performance. BEST Technology has various PCB types of manufacturing technology, which can meet your any type of PCB needs.

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What is the surface mount technology?

Friday, August 23rd, 2024

Surface mount technology (SMT) is a widely used surface assembly method in the electronic assembly industry. It mainly uses automated production equipment to directly solder surface mount components (SMD) to the pads on the surface of the printed circuit board (PCB). SMT has the advantages of high production efficiency, high space utilization, high density and miniaturization. However, it has high requirements for production equipment, processes and operating skills.

What is the surface mount technology process?

The process of surface mount technology (SMT) mainly includes the following steps:

1. Printed circuit board preparation: Before surface mounting, the printed circuit board needs to be prepared first, including cleaning the circuit board, removing the surface oxide layer, and applying solder paste.

2. Component mounting: Use appropriate equipment to accurately mount various electronic components on the printed circuit board.

3. Soldering: After the components are mounted, the solder paste is heated to melt it to form a reliable welding connection.

4. Inspection: After welding, use AOI for automatic inspection to ensure the correct mounting and welding quality of components.

5. Testing and debugging: Test and debug the mounted circuit board, and verify whether the function and performance of the circuit board meet the requirements through specific test equipment and procedures.

Each step needs to be carried out carefully to ensure that the mounted circuit board has good quality and reliability. In addition, surface mount technology is suitable for circuit board assembly, with the characteristics of compact structure and small size, and is widely used in the manufacture of electronic products.

What are the roles of surface mount?

The role of surface mount technology (SMT) is mainly reflected in improving the performance, reliability and production efficiency of electronic products, while reducing the volume and weight of products.

Surface mount technology (SMT) has the following significant effects:

Increase assembly density and reduce product volume: By using surface mount technology, the volume of electronic products can be reduced by 40%~60% and the weight can be reduced by 60%~80%.

‌Improve reliability: SMT has high reliability, low solder joint defect rate and strong vibration resistance.

Optimize high-frequency characteristics: SMT reduces electromagnetic and radio frequency interference and optimizes the high-frequency characteristics of the circuit.

Automated production: SMT is easy to automate, thereby improving production efficiency.

Enhanced compactness: Using small surface-mounted components can save a lot of space on the printed circuit board, and circuit assembly is easier to automate.

Adapt to a wide range of fields: As a new generation of electronic assembly technology, SMT has penetrated into various fields, including but not limited to computers, communication equipment, consumer electronics, etc.

In summary, surface mounting technology has significantly improved the comprehensive performance and production efficiency of modern electronic products by increasing assembly density, optimizing circuit performance, enhancing product reliability, and realizing automated production.

What is the advantage of surface mount?

The advantages of surface mounting mainly include:

High assembly density: Surface mounting technology (SMT) allows more electronic components to be installed in a limited space.

Small size and light weight of electronic products: By using SMT, smaller and lighter electronic products can be manufactured.

‌High reliability‌: SMT has a low solder joint defect rate, which improves the reliability of the product‌.

‌Easy to automate‌: SMT technology is very suitable for automated production and can greatly improve production efficiency‌.

‌Design flexibility‌: SMT allows different components to be used on the same circuit board, providing design flexibility‌.

‌EMC compliance‌: SMT technology helps meet electromagnetic compatibility (EMC) requirements and ensure the safety and performance of the equipment‌.

‌Selective soldering‌: SMT supports selective soldering, which increases the customizability of the product‌.

In addition, SMT technology is cost-effective because the packaging size of components is generally standardized and can be quickly and accurately installed using automated equipment, thereby reducing production costs‌. At the same time, SMT reduces human errors and improves product quality because the placement of components is very consistent, reducing errors or the need for rework.

What are the disadvantages of surface mount?

‌The disadvantages of surface mount technology (SMT) mainly include incompatibility with certain components, the possibility of soldering defects, and high equipment costs. ‌

‌Incompatibility with certain components‌: SMT technology is not suitable for all types of components.

‌Possibility of soldering defects‌: Although SMT technology reduces the need for drilling and shortens setup time, it is not a zero-defect soldering process. In actual applications, SMT may encounter various soldering defects.

‌Higher equipment cost‌: Although SMT technology can improve production efficiency and circuit density, it requires expensive special equipment and professional technicians.

In summary, although SMT technology has many advantages, such as reducing drilling, shortening setup time, and improving production efficiency, it also has some disadvantages, especially in terms of incompatibility with certain components, possible soldering defects, and high equipment costs.

What does SMD stand for in surface mount?

SMD stands for Surface Mounted Devices. ‌

SMD is a type of component in surface mount technology (SMT), which is characterized by small size, high power, stable performance, and easy automated assembly.

SMD packaging technology can maximize the space utilization on the circuit board, especially for the design of dense circuit boards. SMD packaging usually adopts metal oxide semiconductor (MOS) technology, and its packaging methods are diverse, including COB, QFN, LCC, BGA, etc.

In practical applications, the appearance inspection of SMD devices includes visual inspection or use of a magnifying glass to check whether the solder end or pin surface is oxidized or has contaminants, and to ensure that the nominal value, specification, model, accuracy, and external dimensions of the components are consistent with the product process requirements. To ensure the performance and reliability of the device.

The wide application of SMD technology not only improves the performance of electronic products, but also promotes the automation and efficiency improvement of the electronics manufacturing industry. It is an indispensable part of the modern electronics manufacturing industry, especially in applications that require high integration and high reliability.

What is the application of surface mount?

The application of surface mount technology is mainly reflected in improving production efficiency, reducing product volume and weight, and meeting the market demand for miniaturized, lightweight, and high-performance electronic products. This technology is mainly used to mount electronic components on printed circuit boards (PCBs) to achieve circuit connection and system integration.

Surface mount technology can replace traditional through-hole insertion technology, thereby improving product reliability and performance and reducing costs. The technology has a wide range of applications, including but not limited to consumer electronics, military cutting-edge electronics, and fire detectors, manual alarms, and various electronic modules.

In the manufacture of electronic products, surface mount technology has become a revolutionary change, dominating the development of electronic equipment and bringing about major changes in electronic products.

Conclusion:

Usually, the electronic products we use are designed by PCB plus various capacitors, resistors and other electronic components according to the designed circuit diagram, so most electrical appliances require various SMT (patch) processing technologies to process.

BEST Technology focuses on the procurement and processing of various electronic products and processing services for incoming materials, including but not limited to SMT patches, DIP plug-ins, welding, functional testing and maintenance, and assembly proofing and batch production. We can provide proofing, small batch and batch SMT mounting, and can also purchase electronic components and make PCBs.

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