The customs code for printed circuit boards is 8534-0000. 8534 is the classification code for this item, and 0000 represents the sub-classification code under this item. In the actual customs declaration process, it is necessary to select the corresponding sub-classification code according to the specific classification standard of printed circuit boards.
hs code printed circuit board：85340000 PCBs made of FR-4 material (i.e. silicon tetrachloride fiberglass board) are classified under HS code 8534.00.00 hs code printed circuits with more than six layers：85340010 hs code printed circuits with four layers or less:85340090 The HS code for PCB (printed circuit board) is 8534001000. HS code of PCBA is 8543709990
How do you classify printed circuit boards?
According to different classification standards, printed circuit boards can be divided into many types, such as single-sided boards, double-sided boards, multi-layer boards, rigid boards, flexible boards, etc.
The role of HS codes for printed circuit boards
HS codes are a way for customs to classify goods, and are also an important basis for import and export statistics. As an electronic component, printed circuit boards also need to be HS coded so that customs can accurately classify and manage them.
Types of HS codes for printed circuit boards
There are two main HS codes for printed circuit boards: 85340010 and 85340090. Among them, 85340010 is mainly used for printed circuits with more than six layers, while 85340090 is mainly used for printed circuits with four layers or less. The difference between the two codes lies in the number of layers of the printed circuit board, because printed circuits with more than six layers require higher technical requirements and more complex production processes.
How to choose the correct HS code
The specific HS code may vary depending on product specifications, materials and other factors. Therefore, in actual operation, it is recommended to consult relevant departments or professionals according to the specific situation to ensure accuracy. If you are not sure which HS code to choose, you can consult the printed circuit board manufacturer or relevant industry associations for more professional advice.
How do I do a customs declaration?
Declare the code accurately. Select the sub-classification number corresponding to the printed circuit board according to the actual situation to avoid penalties or detention caused by coding errors.
Provide a complete production process. The production process of the printed circuit board needs to be provided in the customs declaration, including the procurement, production, processing, testing and other links of the materials, so as to facilitate the customs inspection of the printed circuit board.
Declare accurate materials and technical parameters. The technical parameters such as the substrate, copper foil thickness, board thickness, drilling diameter, line width, line spacing, etc. used in the printed circuit board need to be accurately declared in the customs declaration.
Re-declaration is required if the dominant production process is changed. If the dominant production process is changed, it is necessary to re-declare to the customs and re-make the customs declaration.
Comply with relevant national quality standards. Printed circuit boards need to meet relevant national quality standards, such as ISO, UL, etc.
hs code electronic,How do I find an HS code?The HS code for PCB (printed circuit board) is 8534001000. PCBs made of FR-4 material (i.e. silicon tetrachloride fiberglass board) are classified under HS code 8534.00.00
Copper weight refers to the amount of copper per square foot of the PCB surface, measured in ounces per square foot (oz/ft²). However, the term “copper thickness” is also commonly used. So, how do copper weight and thickness relate to each other?
Copper thickness is determined by rolling a specific weight of copper over a 1 square foot area. For instance, if 1 ounce of copper is spread out over an area of 1 square foot, the resulting thickness of the copper foil is approximately 1.37mils or 0.0348mm.
What is the Standard Copper Weight for PCB?
The standard copper weight in PCBs typically ranges from 1 oz/ft² to 3 oz/ft². This measurement refers to the weight of copper per square foot. In metric terms, it translates to approximately 35 µm to 105 µm thickness. The choice of copper weight depends on the application and the current-carrying requirements of the PCB. For standard consumer electronics, 1 oz/ft² is often sufficient. However, power electronics and high-current applications may require heavier copper.
What is Copper Thickness in PCB?
PCB typically feature a layer of copper foil bonded to a glass epoxy substrate. Common copper foil thicknesses are 18μm, 35μm, 55μm, and 70μm. The most frequently used thickness is 35μm. In practice, copper foil thicknesses used domestically generally range from 35μm to 50μm, with thinner options like 10μm or 18μm and thicker options like 70μm also available.
For substrates that are 1mm to 3mm thick, the copper foil is typically 35μm thick. On substrates less than 1mm thick, the copper foil is about 18μm thick, while on substrates thicker than 5mm, the copper foil is around 55μm thick.
If a PCB has a copper foil thickness of 35μm and a trace width of 1mm, the resistance per 10mm length of the trace is approximately 5mΩ, and the inductance is about 4nH. When a digital integrated circuit on the PCB operates with a di/dt of 6mA/ns and a current of 30mA, the estimated noise voltage generated in the circuit due to resistance and inductance for every 10mm length of the trace is 0.15mV and 24mV.
Copper Weight vs. Copper Thickness
Here’s a chart illustrating the relationship between copper weight, copper thickness in mils, and copper thickness in millimeters (mm).
Copper Weight (oz/ft²)
Copper Thickness (mils)
Copper Thickness (mm)
0.5
0.7
0.018
1
1.4
0.035
2
2.8
0.070
3
4.2
0.105
4
5.6
0.140
5
7.0
0.175
3
8.4
0.210
How Do You Calculate Copper Weight in PCB?
Calculating copper weight involves determining the thickness of the copper layer. Here’s a simple method:
Measure the thickness of the copper in micrometers (µm).
Use the conversion factor: 1 oz/ft² equals 35.56 µm.
Multiply the thickness by the conversion factor to get the weight in oz/ft².
For example, if the copper thickness is 70 µm, the calculation is:
Copper weight (oz/ft²)=70um/35.56um/oz≈2oz/ft2
You can use a PCB weight calculator to simplify this process, like PCBWay Calculator, Altium PCB Layout Weight Calculator.
How Much Copper is in a PCB?
The amount of copper in a PCB varies depending on the copper weight and the size of the board. For instance, a 10 cm x 10 cm PCB with a copper weight of 1 oz/ft² will have less copper than the same size board with 3 oz/ft² copper weight. To estimate the total copper, you need to know the board area and the copper thickness.
Total copper (grams)=Area (cm²)×Copper thickness (µm)×8.96×10-3
The factor 8.96 x 10^-3 converts the volume to weight, considering copper’s density.
What is the Density of Copper in PCB?
Copper’s density is a constant value of 8.96 g/cm³. This density is crucial for calculating the weight of copper in a PCB. Knowing the density helps in accurately estimating the amount of copper in your PCB, which is essential for both design and manufacturing processes. The density remains constant regardless of the copper weight or thickness, providing a reliable basis for various calculations in PCB design.
Why Copper Thickness is Important for PCB?
In the PCB manufacturing process, copper thickness is a very important factor. The correct copper thickness can ensure the quality and performance of the circuit board, but also ensure the reliability and stability of electronic products. We have listed the following points to show why copper thickness is so important for PCBs.
1. Electrical conductivity
Copper thickness determines the electrical conductivity of the circuit board. As you know, copper is an excellent conductive material, and its thickness directly affects the conductive effect of the circuit board. Thinner copper layer may reduce the electrical conductivity of PCB, and resulting in attenuation of signal transmission or instability of current. And if the copper layer is too thick, although the electrical conductivity will be very good, but will increase the cost and weight of the circuit board. Additionally, thicker copper thickness is easy to lead to serious glue flow, the medium layer is too thin, and increase the manufacturing process difficulty. Therefore, for normal PCB, the copper thickness is generally not recommended to do 2oz copper thick, otherwise you can choose Heavy Copper PCB.
2. Heat dissipation
Copper thickness also has an important impact on the heat dissipation performance of the circuit board. The copper layer is the thermal conductivity layer of the circuit board, and its thickness determines the heat dissipation effect. If the copper layer is too thin, it may cause heat to be unable to conduct and dissipate effectively, increasing the risk of overheating of components. Therefore, the copper thickness of the PCB cannot be too thin, in the PCB design process, we can also lay copper in the blank area to assist the heat dissipation of the PCB board.
3. Improve reliability
Copper thickness also has an important impact on the reliability and stability of the circuit board. The copper layer not only acts as the conductive layer and thermal layer, but also the support and connection layer of the circuit board. The appropriate copper thickness provides sufficient mechanical strength to prevent the board from bending, breaking, or opening welding during use. At the same time, the appropriate copper thickness can ensure the welding quality of the circuit board and other components, reducing the risk of welding defects and failures.
How to Select Suitable Copper Weight for PCB?
Selecting the suitable copper weight depends on several factors:
Current Carrying Capacity
Higher currents require thicker copper to prevent overheating. Calculate the required trace width and copper thickness based on the maximum current your PCB will carry.
Thermal Management
Thicker copper improves heat dissipation, essential for high-power applications. Consider the thermal requirements of your components and ensure the PCB can manage the heat effectively.
Mechanical Strength
Heavier copper can enhance the board’s structural integrity. For applications where the PCB will face mechanical stress or flexing, thicker copper provides added durability.
Cost Considerations
Thicker copper increases material costs, so balance performance needs with budget constraints. While thicker copper offers many benefits, it also comes with higher manufacturing costs. Evaluate whether the additional expense is justified for your specific application.
Signal Integrity
For high-frequency applications, maintaining signal integrity is crucial. Thicker copper can help reduce resistance and signal loss, improving overall performance.
Environmental Factors
Consider the operating environment of the PCB. For harsh conditions, thicker copper may offer better protection against corrosion and environmental stressors.
For most applications, 1 oz/ft² copper is adequate. For power electronics or where higher currents are involved, consider 2 oz/ft² or more. Consult with your PCB manufacturer for recommendations based on your specific use case. They can provide insights into the optimal copper weight for your design, considering both performance and cost-effectiveness.
How to read circuit boards and schematics is a basic skill for anyone interested in electronics. Whether you’re a beginner or a technician, knowing how to read these diagrams is crucial. In this blog, we would like to share the key points and components symbols in the PCB schematics.
How to Understand a PCB Board?
A printed circuit board is a basic of electronic components interconnected via conductive paths printed on a baseboard. We can see it everywhere. They connect and support various components using conductive tracks, pads, and other features. To understand a PCB, start by identifying its main sections: power supply, signal paths, and grounding. Look for the layout patterns, which often follow a logical flow.
Special Types of Circuit Boards
Circuit boards come in various types, each designed for specific applications and processes. Apart from the standard FR4 PCB, metal core PCB, ceramic PCB, rigid-flex PCB, there are some other special PCB uses different process. Here, we’ll explore them based on their unique manufacturing processes, including HDI, busbar, extra thin, IC substrate, high Tg, heavy copper, RF, and impedance control PCBs.
High-Density Interconnect (HDI) PCB
HDI PCBs are designed for compact and complex electronic devices. They feature higher wiring density per unit area compared to traditional PCBs. The process involves microvias, buried vias, and blind vias to create intricate pathways. HDI technology allows for more components on a smaller board, enhancing performance and reducing size. This type of PCB is commonly used in smartphones, tablets, and other high-tech gadgets. The HDI PCBs that Best Technology can make is:
1+N+1
2+N+2
3+N+3
Busbar PCB
Busbar PCBs are specialized boards that handle high current loads efficiently. It belongs to the heavy copper PCB. They use thick copper layers to conduct electricity with minimal resistance. The busbar process involves integrating these thick copper bars within the PCB to distribute power uniformly. They are mainly used in the electric vehicles, power supplies and industrial machinery.
Extra Thin PCB
Extra thin PCBs are designed for applications where space and weight are critical constraints. These boards can be as thin as 0.2mm, allowing them to fit into slim devices like wearables and medical implants. The manufacturing process focuses on using thinner materials and precision etching techniques to achieve the desired thickness without compromising functionality.
IC Substrate PCB
IC substrate PCBs act as the base for integrated circuits (IC). They provide interconnections between the IC and the PCB. These PCBs are crucial in devices like processors, memory modules, and graphic cards, where precision and reliability are paramount.
High Tg PCB
High Tg (glass transition temperature) PCBs are designed to withstand higher temperatures. The Tg value indicates the temperature at which the PCB material transitions from a rigid to a soft state. High Tg PCBs use materials that has over 170 Tg value. So, they are widely used in automotive, aerospace, and industrial applications.
Heavy Copper PCB
Heavy copper PCBs feature significantly thicker copper layers compared to standard PCBs. The process involves plating additional copper to achieve thicknesses of 3oz/ft² or more. These boards handle high currents and thermal cycles, making them ideal for power electronics, motor controllers, and high-power distribution systems.
Radio Frequency (RF) PCB
RF PCBs are designed for high-frequency applications. They use special materials like PTFE (Teflon) to minimize signal loss and interference. This kind of PCB always requires precise control over dielectric thickness and conductor widths to make sure optimal signal integrity. RF PCBs are essential in communication devices, radar systems, and microwave equipment.
What Do the Numbers on a Circuit Boards Mean?
Numbers and letters on a circuit board represent component values, reference designators, and sometimes manufacturing codes. Reference designators (like R for resistors, C for capacitors) help identify each component. The numbers often indicate the order of placement or specific values (e.g., R1, R2 for the first and second resistors).
In addition, some designers prefer to design series number on the PCB board, like 202400001…202400002. For this kind of numbers, they are always aim to easy identification during the assembly or testing.
How to Read Circuit Boards?
Reading a circuit board involves several steps. First, familiarize yourself with the board’s layout and components. Identify key parts such as the microcontroller, resistors, capacitors, and connectors. Trace the pathways or traces to understand the connections. Use the reference designators to match components with their schematic symbols.
Electronic symbols follow standardized guidelines to ensure consistency. The most common standards include IEEE, IEC, and ANSI. These symbols represent various components like resistors, capacitors, diodes, and transistors.
VCC – the positive power supply.
GND – ground or negative power supply.
R – resistor.
C – capacitor.
L – inductor.
Q – transistor or field-effect transistor (FET).
JP – connector or plug/socket.
IC – integrated circuit or chip.
+ / – – input/output terminals of a signal.
NC – no connection or an unused pin.
How Do You Read a Circuit Schematic for Beginners?
Read circuit diagram drawings can be consulted by experienced masters. Generally, the first look when reading a circuit schematic is look at the main loop. And then look at the control loop, the control loop requirements are from top to bottom or from left to right. The circuit diagram mainly consists of four parts: component symbol, connection, node and comment/note.
1. Component Symbols
These represent the actual components in the circuit. Their shapes may not resemble the actual components and can even be completely different. However, they generally indicate the characteristics of the components, and the number of pins matches the actual components.
2. Connections
These represent the wires in the actual circuit. While they appear as lines in the schematic, they are often not lines but various shapes of copper foil blocks on commonly used printed circuit boards (PCBs). For example, many connections in a radio schematic may not be line-shaped on the PCB but rather in specific shapes of copper film.
3. Nodes
These indicate the connections between multiple component pins or wires. All component pins and wires connected to a node are conductive, regardless of the number.
4. Comment/note
These are very important in a schematic. All the text in the schematic can be classified as notes. A close look at the schematics reveals annotations everywhere, used to indicate component models, names, and other information.
Best Technology offer top-quality advanced PCB boards, from prototypes to mass production. Our range includes FR4 PCBs of any Tg, FPC, ceramic PCBs, aluminum PCBs, Teflon PCBs, and copper-base PCBs. Every product and service is traceable and verified with ISO, IATF, RoHS, UL, and REACH certifications. Enjoy free samples for bulk orders, complimentary functional testing, and fast delivery.
TDA7294 is a class AB monolithic audio amplifier integrated circuit launched by SGS-THOMSON Microelectronics in the 1990s. It swept away the raw, cold and hard sound of previous linear integrated amplifiers and thick film integrated amplifiers, and is widely used in HiFi fields, such as home theaters, active speakers, high-performance TVs and other fields.
The chip adopts a 15-pin dual-row asymmetric plug-in package, the differential input stage is composed of bipolar transistors, and the driver stage and power output stage use DMOS field-effect transistor semiconductor technology. This hybrid semiconductor manufacturing process allows TDA7294 to take into account the advantages of bipolar signal processing circuits and MOS power tubes, and the playback sound is very friendly (it is praised by audiophiles as a “tube-flavored amplifier”); the built-in silent standby function, short-circuit current and overheating protection functions make its performance more perfect. It can be used in HiFi home audio, active audio, high-performance TVs and other fields.
Tda7294 amplifier board
tda7294 amplifier board PCBA
This circuit is an official standard circuit, stable and reliable.
The filter uses a large electrolytic capacitor with a withstand voltage of 50V and a capacity of 2200uf.
Power supply voltage: dual 12-36V ring transformer, dual 32V ring transformer is recommended
Output power: 85W*1 undistorted rated power, peak power 100W
Can easily drive speakers above 100W, speaker impedance: 4-8 ohms
PCB size: 50*50mm
Basic parameters: Power supply: dual 18-28V AC Power: 2X80W+160W subwoofer Circuit board size: 218x98MM Potentiometer function: low frequency frequency adjustment, subwoofer volume. Left and right channel volume, treble, bass.
Adopting the new laser dark word TDA7294 The power filter uses 6 63V3300UF capacitors, and the rectifier uses a 25A imported rectifier flat bridge. PCB uses 1.6mm thick double-sided board, 2.0 ounces copper thickness, and full tin spraying process to ensure good passing performance of large and small currents. Fever component assembly, the subwoofer part consists of two new TDA7294 BTL output, The low-pass filter is designed according to the frequency adjustable design of home theater style (50-150HZ), with strong power! The left and right channels are served by two TDA7294 respectively, and the input coupling capacitor uses the German imported WIMA 2.2UF coupling capacitor, which makes the sound sweeter! The signal-to-noise ratio of the board is also very high, and even if you put your ear close to the speaker, you can’t hear the AC noise! It is the best choice for upgrading 2.1 amplifiers!
TDA7294 datasheet
TDA7294 Main Features
Wide supply voltage range: ±10V ~±40V High output power: 70W (up to 100W) Standby and mute functions Noiseless ON/OFF switch Low noise and low distortion Short circuit protection and overheat protection
TDA7294
Pin function Pin 1 is the standby terminal; Pin 2 is the inverting input terminal; Pin 3 is the positive input terminal; Pin 4 is grounded; Pins 5, 11, and 12 are empty pins; Pin 6 is the bootstrap terminal; Pin 7 is +Vs (signal processing part); Pin 8 is -Vs (signal processing part); Pin 9 is the standby pin; Pin 10 is the mute pin; Pin 13 is +Vs (final stage); Pin 14 is the output terminal; Pin 15 is -Vs (final stage)
DIY Production
1) The first step is to get the PCB. Here you can make the PCB yourself by DIY ironing method. Since the PCB is easy to make, the PCB design is kept single layer only, or you can get ready-made quality PCB from best.or custom tda7294 amplifier board. 2) After the PCB is completed, carefully mount all small components like jumpers, resistors, diodes, etc. to the PCB and trim their terminals, then solder them to the PCB first, because there are many components on this board, so it is better to solder them one by one 3) After installing the small components, install the large components like capacitors, fuse holders, rectifiers to the PCB and solder them. (Don’t install the power filter capacitor, 22000uF capacitor for now. Completed in the following steps) 4) After that, it’s time to mount all 7 ICs to the PCB and solder them. 5) Now properly mount the heat sink on the IC using insulating MICA and insulating plastic shoulder washers. Remember to use good quality thermal paste between the heat sink and IC. 6) After mounting the IC on the heat sink. Check the continuity between the heat sink and the IC back plate using a multimeter. There should not be any continuity between them. Please note the heat sink isolation 7) Now mount the cooling fan to the PCB using cable ties or any other suitable method. The board assembly is now complete. Clean the track side of the board using IPA (Isopropyl Alcohol) or cleaning flux and then power the board using a 20-0-20 VAC transformer or a 24-0-24 VAC transformer.
Which one has better sound quality, TDA7294 or LM3886? Voltage AC 28v
LM3886 has better bass because its maximum current can reach 10A, which means it can drive a 2-ohm box without any problems. From the parameters alone, LM3886 is worse than 7294. And it is true in practice, especially for bass. If the transformer is OK, it feels very powerful. 7294 is not as good as 3886 in bass. The current is large when it comes to bass. 7294 itself has overcurrent protection. When the current reaches a certain level, it starts to limit the output current. However, 7294 is better in treble.
A 5.1 amplifier boardis a sound amplifier that can expand the current and voltage of an audio signal to make the sound louder. In addition, a 5.1 amplifier board also has a multi-channel processing function, which can output audio signals through multiple channels to enhance the sound field effect, making listening to music, watching movies, etc. more three-dimensional and realistic. Compared with traditional 0 and 1 amplifiers, in addition to being able to connect two front speakers and two rear speakers, a 5.1 amplifier board can also connect a center speaker and a subwoofer, making the bass of music or movies more prominent and the sound deeper. 5.1 amplifiers are widely used in home theater systems. By combining with projectors, TVs and other equipment, a theater environment with excellent audio-visual effects can be created. In addition, for music lovers, a 5.1 amplifier board is also an indispensable device that can not only maximize the effect of music, but also allow people to experience the charm of music in an immersive way.
5.1 Basic parameters of the amplifier board
Working mode: Class D Quiescent current: 50mA Working efficiency: 90% Rated output power: 2200W+400W Frequency response: 20Hz to 20KHz Working voltage: DC24V-42V( Recommended voltage: DC42V Maximum output current: 10A PCB size: 114109MM Potentiometer center distance: 21.5MM 21.5MM 21.5MM from left to right Original TPA3223 is used
TPA3223 2.1 Digital Bluetooth 5.1 3034 Amplifier Board
1.The front input capacitor and interstage coupling capacitor use ELNA BP capacitor 10UF, the electrolytic capacitor signal main circuit uses Taiwan famous brand, and the main filter capacitor uses imported electrolytic capacitor 1000UF , ensuring strong and continuous power support. 2.The resistors are made of high-precision chip resistors, and the main circuit uses a five-ring metal film resistor with an accuracy of ±1%, which ensures a good signal-to-noise ratio for the whole machine. 3.The PCB uses a 1.6mm thick double-sided board, 2.0 ounces of copper thickness, and a full tin-spraying process to ensure good passing performance of large and small currents. 4.The fully enclosed dust-proof potentiometer is used, which has more stable performance and is more durable than ordinary potentiometers. 5.The red-gray ring high-current inductor and the fully shielded audio-specific output inductor are used to ensure a crisp and powerful sound. The Bluetooth uses Qualcomm QCC3034 5.1 version Bluetooth module
5.1 amplifier board of working principle
The core function of the amplifier board is to increase the amplification factor of the signal while protecting the circuit from damage. The amplifier board is usually used for isolation and current amplification between the programmable logic controller (PLC) and the input device or output device to improve the load capacity of the PLC and protect the PLC from faults such as overvoltage, overload, and load short circuit.
The working principle of the amplifier board is based on the amplifier circuit, using electronic components with amplification characteristics, such as transistors. When the tiny current at the input end changes, a large current change will occur at the output end, and the change at the output end is several to hundreds of times greater than the change at the input end. The characteristic of this amplifier circuit is that only one potential point is amplified, and the other potential point is grounded by default. In addition, the integrated circuit (IC) is also an important part of the amplifier board. It integrates many transistors, resistors, capacitors and other components on a small piece of semiconductor silicon single crystal, and uses isolation technology to insulate them from each other in electrical properties, thereby realizing signal amplification and processing.
For example, an analog signal amplifier board can connect multiple sensors, collect differential signals and amplify them to the required multiples through an amplifier circuit. The board can work normally in the temperature range of -15℃ to 70℃, and the humidity can reach 90%, which is suitable for various harsh environments. This amplifier board is widely used in industrial automation, smart home, medical equipment and other fields to ensure stable signal transmission and processing
The role of the amplifier board
The main functions of the amplifier board:
This is because some process control equipment such as proportional valves can only receive analog voltage or current signals. Therefore, in order to ensure that these devices can correctly receive and respond to the signals sent by the PLC, an intermediate amplification link, namely the amplifier board, is required. It can properly amplify the signal output by the PLC D/A module to make the proportional valve work normally.
The amplifier board is also called the IO relay board. Its main functions include isolation, current amplification, and providing additional I/O channels. It can improve the load capacity and reliability of the PLC system and prevent the PLC host from being damaged due to overvoltage, overload or load short circuit.
The amplifier board is widely used in the field of industrial automation. It can not only improve the load capacity and reliability of the PLC system, but also protect the output or input points of the PLC.
The amplifier board can save cabinet space, increase installation speed, facilitate maintenance and replacement, and has protection circuits and built-in insurance, which makes it difficult to damage the amplifier board itself and the load.
The amplifier board can also play the role of amplifying interference, because its input and output are photoelectrically isolated, and the PLC will not be burned out due to high-voltage impact load. These features make the amplifier board play a vital role in industrial automation systems.
Application of 5.1 amplifier board
5.1 channel amplifiers are mainly used in home theater systems to provide surround sound audio output and an immersive listening experience for the audience. 5.1 channel amplifiers are an indispensable component of home theater systems. They can provide five full-band channels and one low-frequency effect channel. Through carefully designed audio processing, the audience can feel the sound from different directions, thereby enhancing the immersion of movies or concerts.
In addition to home theater applications, 5.1 channel amplifiers are also suitable for professional audio systems, such as conference rooms, performance venues, etc., where high-quality audio output is required. In these occasions, 5.1 channel amplifiers can ensure stable signal transmission and high-quality restoration to meet professional-level audio needs.
In short, the 5.1 channel amplifier board provides multi-channel audio output, bringing a more realistic and three-dimensional sound experience to viewers or listeners, playing an important role in both home entertainment and professional applications.
FAQs About 5.1 amplifier board
Does the 5.1 amplifier front panel consist of 6 front panels?
A true 5.1 should have 6 input interfaces (marked as: 5.1IN) and 6 speakers including a subwoofer.
5.1 is an independent 6-channel amplification and 6-channel speaker restoration, and of course an independent 5.1-channel sound source is required.
The 5.1 speaker requires the amplifier to have an independent 6-channel amplifier. Virtual ring. Winding into multiple channels
How many power amplifiers are there in a 5.1 channel amplifier? Two situations, the first is 5.1 full-channel power amplification, that is, 6 channels, but in this case the power of the bass channel is small, which can drive 6~8-inch bass, but it can’t drive large ones. The second is 5-channel power amplification, except for the bass channel, the other channels are power amplified, the bass channel only provides a level signal, and the signal enters the active subwoofer amplifier board to drive the subwoofer, which is more common.
Can the 5.1 channel amplifier board use dual DC?
Ordinary transistor power amplifiers use DC. What do you mean by “using dual DC power”? Does it mean using a backup power supply? … Using a backup power supply is completely possible.
In addition, there are power amplifiers that are powered by [positive and negative symmetrical power supplies]. Such power amplifiers must use DC positive and negative symmetrical power supplies.
Can I make a 5.1 with two 2.1 amplifier boards?
One of them is used for 2.1 (the analog subwoofer circuit is removed as bass amplification), and the other is used for surround channels (remove the subwoofer circuit and change to center). After merging, it is 5.1. The 6 amplification channels must be connected to the 5.1 decoding output.
Can a 5.1 pre-stage board be used with a 2.0 amplifier? It can definitely be used. The pre-stage board only plays the role of audio adjustment and does not perform power amplification. The input audio signal can be connected to the amplifier after being adjusted and output by the pre-stage board. For the 5.1 channel, just select 2 of the output signals.
When communicate with clients, they always ask why the PCB board are so expensive? Is there any basis for that? Actually, the price of PCBs are made specifically according to its manufacturing process, layers, complexities and so on. Today, Best Technology is deeply sharing the composition of PCB cost. Welcome to keep reading.
Why is PCB Board So Expensive?
The cost of a PCB can sometimes seem high due to several reasons. Firstly, the complexity of the design plays a significant role. High-density interconnect (HDI) PCBs, multi-layer PCBs, and those requiring advanced materials or special finishes can drive up the cost. Additionally, stringent quality control measures and the need for precise manufacturing processes add to the expense.
Another factor is the cost of raw materials. Copper, laminates, and specialty substrates can vary in price, affecting the overall cost of the PCB. Furthermore, labor costs in the region where the PCB is manufactured, along with overhead costs such as utilities and facility maintenance, contribute to the final price.
What Factors Affect the PCB Board Cost?
PCB board can cost from $10 to $500 to produce. Buyers are always amazing that why PCB cost so high? But they don’t know there are numerous factors a manufacturer considers in determining PCB costs. If you are in the market to design a PCB, this guide provides factors to consider that could increase or decrease the cost of circuit boards.
Manufacture technology
The specific technology used in the PCB can significantly impact the cost. Advanced technologies such as HDI (High-Density Interconnect), embedded busbar or flexible PCBs often require more complex manufacturing processes, which can increase the cost.
Material Type
The type of materials used for the PCB, such as standard FR4, high-frequency laminates, or other specialty substrates, can influence the cost. Higher quality or specialized materials typically cost more.
IPC Grade
The IPC standards and grades indicate the quality and reliability requirements of the PCB. In electronics manufacturing, printed circuit boards are divided into three levels: level 1, level 2 and level 3. These grades reflect the quality level of each board type, from the lowest (Level 1 standard) to the highest (Level 3 standard). This classification system was developed and defined by IPC and is specified in the IPC-6011 series.
Circuit Design
The complexity of the circuit design, including the number of layers, trace width, and spacing, affects the cost. More intricate designs require more precision and advanced techniques, leading to increased expenses.
PCB Size & Yield
The physical dimensions of the PCB and the yield rate during production play a role in the overall cost. Larger boards or designs with lower yield rates (more defects) will typically cost more to produce.
Material Thickness
The thickness of the materials used in the PCB construction, such as the substrate and copper layers, can impact the cost. Thicker materials may be more expensive and require more resources to process.
Copper Thickness
The thickness of the copper used in the PCB, measured in ounces per square foot, can affect the cost. Thicker copper layers provide better electrical performance but are more expensive.
Stack-up
The method of layering and stacking the materials in the PCB, known as the stack-up configuration, can influence the cost. Complex stack-ups with multiple layers and specific arrangements can be more costly to manufacture. Read our another post of How Can I Reduce and Optimize the Cost of My PCB in A Best Way?
Manufacturing Process of A Standard PCB
PCB Design and Layout
The manufacturing process begins with the design phase, where engineers use CAD (Computer-Aided Design) software to create the PCB layout. This includes defining the circuit paths, components, and layers, ensuring the design meets the electrical and mechanical requirements.
Once the design is finalized, a photomask is created, which is a transparent film with the PCB design printed on it. The PCB substrate, typically made of FR4, is then coated with a light-sensitive material called photoresist.
Drilling
Precise holes are drilled into the board for through-hole components and vias using computer-controlled drilling machines. The board is cleaned and deburred to remove any rough edges or debris from the drilling process.
Plating and Copper Deposition
A thin layer of copper is deposited on the surface of the board and inside the drilled holes through an electroless plating process, providing a conductive base. Additional copper is electroplated onto the board, building up the thickness of the copper traces and plated through-holes.
Pattern Transfer
The photomask is placed over the photoresist-coated substrate and exposed to ultraviolet (UV) light. The UV light hardens the photoresist where the design allows light to pass through, and the board is then developed to wash away the unhardened photoresist, leaving behind the desired circuit pattern.
Etching
The PCB undergoes an etching process using a chemical solution to remove unwanted copper, leaving only the copper traces that form the circuits. The remaining hardened photoresist is then stripped away to reveal the clean copper pattern.
Applying Solder Mask
A layer of solder mask is applied to the board to protect the copper traces from oxidation and prevent solder bridges during assembly. The solder mask is cured using UV light, hardening it and making it durable.
Surface Finish/Surface Treatment
A surface finish is applied to the exposed copper areas to protect them and facilitate soldering. Common finishes include HASL (Hot Air Solder Leveling), ENIG (Electroless Nickel Immersion Gold), and OSP (Organic Solderability Preservatives).
Outline Routing
One the surface treatment finish, it will be routed according to the manufacturing file by CNC machine. And then individual PCBs are cut from the larger panel using routing or V-scoring, depending on the board design and requirements.
Electrical Testing & FQC
The PCB undergoes electrical testing to check for short circuits, open circuits, and other defects. This is typically done using a flying probe tester or a bed-of-nails tester. Then the board is visually inspected for any cosmetic defects or anomalies, and further tests and inspections are performed to ensure the PCB meets all specified requirements and standards. Below you can see the full manufacturing process video of a PCB:
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Common PCB failures are mainly concentrated on components such as capacitors, resistors, inductors, diodes, transistors, MOSFETs, integrated chips (IC), and crystals. Some obvious damages can be visually detected, while others require the use of tools. Today, let’s learn how to troubleshoot PCB faults using a multimeter.
How Will You Diagnose a Faulty PCB By Visually?
For some printed circuit boards, we can check by our naked eyes. Here are some common ways to follow:
1. Check the condition of components
When you get a faulty PCB, first observe if there are any obvious component damages, such as burnt or swollen electrolytic capacitors, burnt resistors, and damaged power devices.
2. Inspect the soldering of the PCB
Check if the printed circuit board (PCB) is deformed or warped; if there are any loose or poorly soldered joints; if the copper cladding on the PCB is lifted, burnt, or blackened.
3. Examine the component plug-ins
Ensure the correct orientation of integrated circuits, diodes, and the PCB power transformer.
How to Check PCB with a Multimeter?
Before you start testing your PCB, ensure you have the right tools and environment. Here’s a checklist to get you started:
1. Safety First: Wear anti-static gloves and ensure you are working on an anti-static mat to prevent damage to the PCB.
2. Multimeter Selection: Choose a multimeter with the ability to measure voltage, resistance, and continuity. A digital multimeter is preferred for accuracy.
3. Visual Inspection: Examine the PCB for visible signs of damage such as burnt components, broken traces, or solder bridges.
4. Power Off the Board: Always test the PCB with the power off to avoid any electrical hazards and damage to the multimeter.
How Do You Test Individual Components on a PCB?
Testing individual components like resistors, capacitors, and diodes can pinpoint the exact failure. Here’s a general approach:
Diode
Transistor
MOSFET
Electrolytic Capacitors
How to Test Diodes?
1. Set the MF47-type multimeter to measure resistance.
2. Place the red and black probes on the two ends of the diode and read the value.
3. Swap the probes and measure again.
4. Judge based on the two measurements: the forward resistance of small power germanium diodes is 300-500Ω, silicon diodes are about 1kΩ or larger. The reverse resistance of germanium diodes is tens of kilo-ohms, and silicon diodes are above 500kΩ (values are much smaller for high-power diodes). A good diode has low forward resistance and high reverse resistance, and the larger the difference, the better.
5. If both forward and reverse resistances are very low, the diode is short-circuited; if both are very high or infinite, the diode is open-circuited and needs to be discarded.
How to Test Transistors?
1. Set the digital multimeter to the diode mode.
2. Measure the PN junction with the probes. If it conducts forward, the displayed value is the forward voltage drop of the PN junction.
3. Determine the collector and emitter: measure the forward voltage drop of the two PN junctions, the larger drop is the emitter (e), and the smaller drop is the collector (c). If the red probe is connected to the common terminal, the transistor is NPN type, and the common terminal is the base (b); if the black probe is connected to the common terminal, the transistor is PNP type, and the common terminal is the base (b).
4. For in-circuit testing, measure the forward and reverse resistance of the PN junction to determine if the transistor is damaged. If the branch resistance is larger than the forward resistance of the PN junction, there should be a clear difference between the forward and reverse resistances, otherwise, the PN junction is damaged.
The Way to Test MOSFETs?
1. Connect the black probe to the drain (D) and the red probe to the source (S), the resistance should be 500-600.
2. Without moving the black probe, touch the gate (G) with the red probe, then measure the source (S) again; it should conduct.
3. Connect the red probe to the drain (D), touch the gate (G) with the black probe, then measure the source (S); the resistance should be the same as the first measurement, indicating the MOSFET is working normally.
How to Test Electrolytic Capacitors?
1. Select the appropriate range on the MF47-type multimeter based on the capacitor’s capacity. Use R×1K range for capacitors below 47μF, and R×100 range for those above 47μF.
2. Connect the red probe to the negative lead and the black probe to the positive lead of the capacitor.
3. On initial contact, the multimeter needle will deflect right and then gradually return to the left until it stops at a certain position (close to infinity). This value is the capacitor’s forward leakage resistance; the larger the value, the better the capacitor’s performance.
4. Swap the probes and repeat the process. The measured value will be the reverse leakage resistance, slightly smaller than the forward leakage resistance.
5. If no charging phenomenon occurs (the needle doesn’t move), the capacitor is either open or short-circuited internally. If the resistance is very small or zero, the capacitor is leaky or has broken down and cannot be used.
This is the end of this article, if you want to know more about it, welcome to contact us.
hs code electronic (HS codes) for electronic products involve multiple categories and specific commodities, including but not limited to laptops, tablets, portable devices, phones, electronic watches, smartphones, electronic game consoles, electric toys, electronic cigarettes, etc. The HS codes for these commodities are as follows:
The HS code for laptops and tablets is 8471301000. The HS code for portable devices is 8471309000. The HS code for phones is 8517129000. The HS code for electronic watches is 9102190000. The HS code for smartphones is 8517130000. The HS code for electronic game consoles is 9504901000. The HS code for electric toys is 8501101000. The HS code for electronic cigarettes is 8516799000. The HS code for PCB (printed circuit board) is 8534001000. PCBs made of FR-4 material (i.e. silicon tetrachloride fiberglass board) are classified under HS code 8534.00.00 HS code for integrated circuit and microelectronic component parts is 8542900000 Electronic circuit boards: HS code is 8534.00.00 Capacitors: HS code is 8532.10.00 Resistors: HS code is 8533.10.00 Transistors: HS code is 8541.10.00 Integrated circuits: HS code is 8542.31.00 Connectors: HS code is 8536.69.00
These HS codes are the standards used by customs to classify and count goods in international trade. Each commodity has a specific HS code to facilitate customs management and statistics of imported and exported goods. Knowing these codes is very important for companies and individuals engaged in international trade, as it can help them declare goods correctly and avoid mistakes in tariffs or customs declarations.
How do I find an HS code?
You’ll often find HS codes on invoices and shipping documents around the world. HTS codes are like Schedule B numbers, but for importing goods into the United States instead. They’re also made up of 10 digits, and they help the US government to track imports and apply the right tariffs to different products.
HS code is a coding system consisting of six digits, each of which represents specific information in order to accurately define and classify goods. The following is the basic structure of HS code:
The first digit (chapter): represents the major category of goods, usually describing the general nature of the goods, such as raw materials, machinery and equipment, electronic products, etc.
The second digit (section): further subdivides the major category of the first digit to provide more specific information.
The third digit (subsection): continues to refine the classification of goods, usually including the materials and uses of goods.
The fourth digit (group): describes the specific characteristics and attributes of the goods.
The fifth digit (subgroup): provides more specific information related to the characteristics of the goods.
The sixth digit (item): the most specific code, used to identify specific goods.
What is the HS code for circuit boards?
he HS code for circuit boards is a standard international commodity code, the full name of which is “HS code for printed circuit boards”, which is part of the customs coding system. The coding system was formulated by the World Customs Organization (WCO) to uniformly identify the classification and classification of international goods.
The role of the HS code for circuit boards
The HS code for circuit boards is an important voucher in international trade, which can help customs to quickly and accurately count and classify imported or exported goods. At the same time, it is also an important basis for customs to determine tariff rates, levy import tariffs, supervise trade measures, and implement regional protectionist policies.
Classification of HS codes for circuit boards
According to WCO regulations, the HS code for circuit boards is divided into 16 chapters, Chapters 1 to 5 are industrial product codes, Chapters 6 to 14 are agricultural product codes, Chapter 15 is unlisted commodity codes, and Chapter 16 is supplementary codes for machinery and equipment. Among them, the HS code classification of circuit boards is in Chapter 85, which belongs to machinery and electrical equipment.
Application of HS code of circuit boards
HS code of circuit boards is one of the key points in international trade. Reasonable coding will have an important impact on trade costs and trade efficiency. When conducting import and export trade activities of circuit boards, relevant HS codes must be correctly declared, otherwise they may face customs control, return, fines and other consequences. Therefore, the correct understanding and application of HS code of circuit boards is of great significance to the commercial success of enterprises.
As a basic work in international trade, HS code of circuit boards not only plays an important role in facilitating and smooth trade, saving costs and improving efficiency, but also is a key link in the import and export trade of circuit boards. Therefore, enterprises should attach great importance to the correct understanding and application of HS code of circuit boards, making it a powerful tool to promote the development of enterprises.
led ring light pcb leads the development of lighting industry with its innovative design, high efficiency and flexibility, bringing more intelligent and comfortable lighting experience to our life.
It is not only an integrated platform of electronic components, but also a perfect combination of modern technology and aesthetics, and is the focus of future lighting trends.
led ring light pcb, like a magic wand on the electronic stage, uses precise SMT technology to lightly attach LED components to it. Whether it is a warm small lamp for home decoration, efficient lighting in commercial space, or smart display inside the car, it is indispensable.
Its core structure includes efficient LED lamp beads, power cords that provide electricity, and intelligent controllers that adjust light effects, which together build an excellent lighting solution.
What Is led ring light pcb
Why use mcpcb for led ring light pcb
With the continuous development of LED technology, the heat generated by LEDs has gradually increased. The traditional FR4 printed circuit board (PCB) has been unable to meet the heat dissipation requirements due to its low thermal conductivity (only 0.36W/m.K). In order to solve this problem, the metal core printed circuit board (MCPCB) was proposed. It attaches the original printed circuit board to a metal with better thermal conductivity (such as aluminum and copper) to enhance the heat dissipation effect. The thermal conductivity efficiency of MCPCB is higher than that of traditional FR4 PCB, reaching 1W/m.K to 2.2W/m.K, which effectively improves the heat dissipation performance of LED PCB.
In addition, the use of MCPCB can also reduce the number of LEDs required to generate lighting, making it an ideal choice for street lights, automotive LED applications, and backlight unit applications. The use of metal substrates has practical advantages in heat dissipation, thermal conductivity, reliability, and electrical insulation, especially in harsh environments, and can also achieve reliable operation of LEDs. For example, using a metal substrate can reduce the LED junction temperature by 20-30°C, improve light output and enhance the overall performance of the product, ensure consistent UV light generation, and expand the possibilities of UV applications in various industries.
Unveiling the Components of LED PCBs
LED Chips: The heart of the LED PCB, these semiconductor chips emit light when current passes through them.
Substrate Material: The base layer of the PCB provides mechanical support and thermal conductivity.
Copper Traces: These conductive pathways connect the LEDs and other components, allowing current to flow through the circuit.
Solder Mask: A protective layer that covers the copper traces, safeguarding them from external factors and preventing short circuits.
Silkscreen: This layer contains markings and labels, providing important information about the PCB’s components and assembly.
Advantages of led ring light pcb?
Thermal performance advantages of metal substrate PCB
High thermal conductivity: The thermal conductivity of metal substrate PCB is much better than that of traditional plastic substrates such as FR4. It can effectively conduct the heat generated by components, reduce the operating temperature of components, and improve the reliability and life of circuit boards.
Good thermal stability: Metal substrate PCB can maintain good dimensional stability and electrical performance in high temperature environment, and is suitable for high temperature working environment.
Mechanical performance advantages of metal substrate PCB
High strength: Metal substrate PCB has high mechanical strength and rigidity, is not easy to deform and break, and can withstand large external forces and vibrations.
Good processability: Metal substrate PCB can be processed by conventional mechanical processing methods such as drilling and cutting, which is convenient for the production of circuit boards with complex shapes and sizes.
Electrical performance advantages of metal substrate PCB Excellent electrical insulation performance: Metal substrate PCB has a special insulation layer design to ensure good electrical insulation performance and avoid electrical short circuits between components.
Low impedance: The conductive layer of metal substrate PCB is made of metal material, which has low impedance, which is conducive to signal transmission and processing.
How does led ring light pcb dissipate heat?
The power device is mounted on the circuit layer. The heat generated by the device during operation is quickly transferred to the metal base layer through the insulating layer, and then the metal base layer transfers the heat to achieve heat dissipation of the device.
Compared with the traditional FR-4, the aluminum substrate can reduce the thermal resistance to the minimum, making the aluminum substrate have excellent thermal conductivity; compared with the thick film ceramic circuit, its mechanical properties are extremely good.
In the circuit design scheme, the heat diffusion is handled very effectively, thereby reducing the module operating temperature, extending the service life, and improving the power density and reliability; reducing the assembly of the heat sink and other hardware (including thermal interface materials), reducing the product volume, and reducing the hardware and assembly costs; combining the power circuit and the control circuit
How to make a LED light circuit board?
Step 1: Design Your LED PCB: Using PCB design software, create a schematic for your LED circuit and design the PCB layout, considering component placement and signal flow.
Step 2: Choose the Materials: Select a suitable substrate material and copper-clad board based on your project requirements.
Step 3: Transfer the Design: Print your PCB layout onto a special transfer paper and transfer it onto the copper-clad board using a heat press.
Step 4: Etch the Board: Immerse the board in an etching solution to remove the excess copper and reveal the copper traces.
Step 5: Drill Holes: Drill holes on the board to accommodate the LED chips and other components.
Step 6: Solder the Components: Carefully solder the LED chips and other components onto the board, ensuring secure connections.
Step 7: Test Your LED PCB: Connect your LED PCB to a power source and test the LEDs to ensure they light up correctly.
How to make a LED light circuit board?
Capabilities of led ring light pcb?
Item
Capabilities
Layer Count
1 – 10 Layers
Max Board Dimension
24*64″(610*1625mm)
Min Board Thickness
0.6mm
Max Board Thickness
4.0mm
Conductor Thickness
0.5oz – 10oz
Min Line Width/Line Space
4/4mil (0.10/0.10mm)
Min Hole Diameter
10mil (0.25mm)
Min Punch Hole Dia
0.12″ (3.0mm)
Min Hole Spacing
16mil (0.4mm)
Min PAD Ring(Single)
3mil (0.075mm)
PTH Wall Thickness
Normal: 0.59mil (15um); HDI: 0.48mil (12um)
Min Solder PAD Dia
14mil (0.35mm)
Min Soldermask Bridge
8mil (0.20mm)
Min BAG PAD Margin
5mil (0.125mm)
PTH/NPTH Dia Tolerance
PTH: ±3 mil (0.075mm); NPTH: ±2mil (0.05mm)
Hole Position Deviation
±3mil (0.075mm)
Outline Tolerance
CNC: ±6 mil (0.15mm); Die Punch: ±6 mil (0.1mm)
Max Aspect Ratio
10:01
Surface Treatment
ENIG, Flash Gold, Hard Gold Finger, Gold Plating(50mil), Gold finger,
Application in medical equipment The rapid progress of medicine is closely related to the rapid development of the electronics industry. Many medical devices are made of basic PCBs alone, such as pH meters, heart rate sensors, temperature measurements, electrocardiographs, electroencephalographs, MRIs, X-ray machines, CT scanners, blood pressure machines, blood sugar level measuring equipment, etc.
Application in industrial equipment PCBs are widely used in manufacturing, especially in industries with high-power mechanical equipment; these devices run on high power and require high current circuit drive. Such as arc welding, large servo motor drives, lead-acid battery chargers, clothing cotton machines, etc.
Application in lighting LED lights and high-intensity LEDs are mounted on PCBs based on aluminum substrates; aluminum has the property of absorbing heat and dissipating it in the air.
Application in the automotive and aerospace industries Flexible PCBs are lightweight but can withstand high vibrations. Because of their light weight, they can reduce the total weight of spacecraft; flexible PCBs can be adjusted even in narrow spaces. These flexible PCBs are used as connectors, interfaces, and can be assembled even in compact spaces
FAQs About led ring light pcb
What is the thermal conductivities and withstanding voltages of BT/FR4 layer and Dielectric layer? The SinkPAD conducts heat primarily through the copper base (400W/m.K), the withstanding voltages of Dielectric layer is around 4KV.
What is the placement accuracy for the SMT components? +/-0.05mm is our SMT accuracy tolerance. You are welcome to come to our SMT factory in Shenzhen China and Vietnam.
Can the aluminum be made as the base of sinkpad MCPCB?
Actually, the sinkpad can only use copper as the base. As you can see the below manufacturing steps, the SinkPad will etch the copper base into convex platform with Copper Etching Solution, then hollow out the Double Layer FR4 PCB, and do lamination with the convex platform. However, regarding of current technical conditions, since aluminum or aluminum alloy cannot directly react with acid, the reaction process is too complex and difficult to control, which will increase the difficulty of etching the LED pad platform. Considering the scrap rate, the process of etching LED pad platform with aluminum is more complex and the overall cost is higher.
Can I plated copper in mcpcb via holes? Generally speaking, copper plating through holes requires hole rings, otherwise the copper in the hole wall will easily fall off.
In addition, if it is a copper substrate, through the hole first to resin plug before copper plating.
Otherwise there’s no chemical reaction between copper and copper. And if the copper layer is connected to each copper layer, it is easy to short circuit.
Are you UL certified led pcb manufacturer?
Yes, we are UL certified manufacturer, our UL is E475635. We have already passed UL certificated. Meanwhile, we are passed ISO9001, ISO13485 and IATF16949 certifications.
Our LED pcbs are manufactured under highly monitored by these quality system controls.
How does the conveity of sinkpad manufactured?
Actually the sinkpad can only use copper as the base.
As you can see the below manufacturing steps, the SinkPad will etch the copper base into convex platform with Copper Etching Solution, then hollow out the Double Layer FR4 PCB, and do lamination with the convex platform.However, regarding of current technical conditions, since aluminum or aluminum alloy cannot directly react with acid, the reaction process is too complex and difficult to control, which will increase the difficulty of etching.
Nowadays, PCBs became more and more important and you can see it in every electronic device. The PCB plays a critical role in our daily life. With circuit board, the device can power on and help to transmit signals, manage heat and perform electricity. A good PCB can help to improve the overall of your device. However, not all the PCBs are work good and within your expectable, you must know how to test it and ensure it enables a good performance. As an experienced PCB manufacturers in Asia, today we want to share with you how we test a PCB, and we try to use simple words to make you sense.
What is a printed circuit board?
Before knowing the methods of testing circuit board, let’s understand the definition of PCB. A PCB is a flat board made from insulating materials like fiber glasses with conductive pathways etched onto its surface. The pathways we called circuit or traces. These pathways connect different electronic components, so that they can communicate and function together. PCBs come in various materials, shapes and sizes, which always is customized to meet specific applications and performance requirements.
PCBs can be divided into different types according to substrate material used. They are – normal FR4 PCB, polyimide flexible PCB, metal core PCB, ceramic PCB, rogers PCB. Different has its own properties and advantages. The choice of materials and the design of the PCB significantly impact the performance and reliability of the final product. Understanding the materials used in PCBs is crucial for anyone involved in electronics, from hobbyists to professional engineers/designers.
Common PCB Circuit Board Issues
Though PCB has a strong construction, they are easy to be broken or failure since they always encounter a range of issues. These problems can stem from manufacturing defects, wear and tear, or improper handling. Identifying and diagnosing these issues promptly is crucial for maintaining the reliability and performance of electronic devices. Common issues we faced are including:
Open Circuits: These occur when a break in the circuits prevents current flow normally. Open circuits can result from physical damage or manufacturing errors.
Short Circuits: Due to improper soldering, unreasonable circuit design and other reasons, resulting in a short circuit between two or more points in the circuit that should not be connected. This can cause excessive current flow, potentially damaging components.
Grounding: The unreasonable design of ground area leads to interference signals on the grounding, which affects the normal operation of the circuit.
Signal: The signal circuit design is not reasonable, resulting in interference signals on the signal.
Component Failures: Individual components on a PCB can fail due to aging, overheating, or electrical stress breakdown. And incorrect orientation will lead to the failure of PCB.
Soldering Issues: Poor soldering can lead to weak connections, causing intermittent faults or complete circuit failure. This including the dents in the solder joints, this also can make the PCB failure.
Corrosion: PCB exposure to moisture and contaminants for a long time can cause corrosion, degrading the conductive pathways and component leads.
How to check a PCB?
In generally, there are four common ways to check whether if your PCB are good or failure.
1. Visual inspection
The easiest way is visual inspection. Through naked eye observation, check whether the solder joint on the PCB circuit board is firm, whether there is short circuit, open circuit and other phenomena. And look for burnt components, discolored areas, or broken traces, such as somewhere became black or be burned obviously. These are clear indicators of damage.
2. Use a multimeter
Multimeter is a common tool used for measuring PCB. Multimeter is versatility and it has multiplied modes. Select the appropriate mode on the multimeter, such as continuity, voltage, or resistance mode, depending on what you are testing. Before testing, make sure probes are in good condition and properly connected to the multimeter, with the red probe typically being positive and the black probe negative or ground. Click here to read What is the PCB flying probe test?
3. E-tester
E-tester is a good way to test short or open circuit when it is a mass production. If you just want to test one piece PCB, multimeter is much better.
4. Use oscilloscope
An oscilloscope is a powerful diagnostic tool used to observe the waveform of electrical signals in a circuit. Connect the oscilloscope probes to the test points on the PCB, it can capture the waveform. By observing the waveform, determine whether the circuit is working normally.
5. Use a thermal imager
A thermal imager also is a effective way to check the condition of PCB. It can capture the temperature distribution on the PCB. It helps identify areas with excessive heat, which can indicate potential issues.
How to Test a Circuit Board with a Multimeter Effectively?
Testing a circuit board with a multimeter is essential for diagnosing and fixing electronic issues. A multimeter can measure voltage, current, and resistance, helping you identify problems with the PCB. The main way to test a PCB with a multimeter is to measure voltage, resistance, and ground.
Measuring voltage
By measuring the voltage on the circuit board, can quickly test whether the circuit is working properly. Use the voltage gear of the multimeter, select the appropriate range, then measure the input and output of the power supply on the circuit board respectively, to check whether the voltage is within the normal range. If the voltage is abnormal, may indicate that the circuit is open or short.
Measuring resistance value
By measuring the resistance value on the circuit board, can detect whether the circuit is smooth. Use the resistance level of the multimeter, select the appropriate range, then measure the key nodes on the circuit board, check whether the resistance value is within the normal range. If the resistance value is abnormal, may indicate that the circuit is open or short.
Check the grounding
Grounding is critical to the proper operation of the circuit board. Use the multimeter’s ground test function, to check that key points on the board are properly grounded, this helps to spot potential electrical connection problems.
In addition, for industrial-grade PCB measurement, the use of higher-precision multimeters and special pens can improve the accuracy and efficiency of the measurement. For example, the Fluke 17B Max multimeter is equipped with an extra-pointed stylus, enables more accurate measurement of patch components and pins, and improves measurement fineness and accuracy.
Generally speaking, using a multimeter to test the PCB board needs to master the correct measurement methods and skills. At the same time according to the complexity of the circuit board to choose the appropriate measurement tools, to ensure the accuracy and efficiency of the test.
How to Tell if a Circuit Board is Bad?
Identifying a bad circuit board requires a combination of visual inspection and multimeter testing. Here are some signs and methods to determine if a PCB is faulty:
Visual Signs
Look for burnt components, discolored areas, or broken traces, such as somewhere became black or be burned obviously. These are clear indicators of damage.
Component Testing
Use the multimeter to test individual components. A component that doesn’t show the expected resistance or voltage is likely faulty.
Continuity Testin
Check for open circuits. Lack of continuity in a path indicates a broken trace or solder joint.
Short Circuit Detection
Identify any unintended connections between different paths. This can be done by checking for continuity where there should be none.
Functionality Testing
Test the circuit board in its intended application. If the device does not function correctly, there may be an issue with the PCB.
Why Choose Best Technology?
By reading this post, you may know how to test a PCB by multimeter already and other methods to identify them. Best Technology has engaging in the PCB manufacturing for more than 18 years, we have served over 2000+ customers all around the world. We have strong R&D team and equipped with advanced equipment to improve the yield and product quality.
At Best Technology, we provide various PCB manufacturing, including metal core PCBs, ceramic PCBs, rigid-flex PCBs and some other special PCBs like HDI PCB, busbar PCB, heavy copper PCB. If you have similiar projects, you are welcome to contact us.
