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What is a PCB Board? – Best Technology
Saturday, July 13th, 2024

In our daily life, the electronics has been gradually infiltrated our lives. Between them, the PCB board plays an important role in it, and we must say, PCB is the foundational element of electronics. From the simplest gadgets to the most complex machinery, PCBs play a crucial role.

What is a PCB Board?

A printed circuit board (PCB) is an electronic that uses metal conductors to create electrical connections between components. Generally, a PCB is a flat, laminated composite made of non-conductive substrate materials with conductive pathways etched or printed onto it. These pathways, also known as traces, enable the electronic components mounted on the board to communicate with each other.

What is a PCB Board?

PCBs are designed to support and electrically connect various components such as resistors, capacitors, diodes, and integrated circuits. The intricate network of copper tracks forms circuits that dictate the device’s functionality. PCBs can range from simple single-sided boards used in basic electronics to complex multi-layered structures found in advanced applications.

Common PCB Structure

A PCB’s structure is composed of several key layers, each serving a distinct purpose. Here is a detailed breakdown of these layers:

Substrate (Base Material)

The substrate, usually made of fiberglass (FR4), provides the board with its rigidity and thickness. It is the foundational layer upon which all other materials are built.

Copper Layer

This conductive layer is typically made of copper foil. For single-sided PCBs, the copper layer is only on one side of the substrate, whereas double-sided and multi-layer PCBs have copper layers on both sides or between multiple layers of substrate.

Solder Mask

The solder mask is a protective layer applied over the copper traces to prevent oxidation and accidental short-circuiting. It insulates the copper traces and leaves the component pads exposed for soldering. The green color commonly associated with PCBs comes from this layer, though it can also be found in other colors like red, blue, black, and white.


The silkscreen layer is used to add labels, symbols, logos, and other markings to the PCB. This layer helps in identifying component locations and orientations during assembly and troubleshooting.

Components and Connectors (PCBA)

Components such as resistors, capacitors, diodes, and integrated circuits are soldered onto the PCB. Connectors allow the PCB to interface with other boards, power supplies, and external devices.

What is a PCB Board?

How Many Types of PCB?

Single-Sided PCBs

These are the simplest types of PCBs, with copper on only one side of the board. You’ll find them in basic, low-cost electronics like calculators, radios, and power supplies. They’re easy to design and manufacture, which keeps costs down and makes them great for straightforward applications.

Double-Sided PCBs

These boards have copper layers on both sides, allowing for more complex circuits. They’re common in more sophisticated electronics like amplifiers, power monitoring systems, and HVAC systems. With increased circuit density and flexible design options, they can handle more complex tasks.

Multi-Layer PCBs

When you need to pack in a lot of circuits, multi-layer PCBs are the way to go. They consist of three or more layers of copper, separated by insulating layers. You’ll see these in high-tech devices like computers, servers, medical equipment, and aerospace electronics. They offer high circuit density, reduced size and weight, and better signal integrity.

Rigid PCBs

Made from solid, inflexible materials like fiberglass, rigid PCBs keep their shape and provide strong support for components. They’re durable and used in everything from simple toys to complex industrial equipment.

Flexible PCBs

These are made from flexible plastic materials like polyimide, allowing them to bend and flex. Perfect for wearable electronics, flexible displays, and compact devices where space is tight. They’re lightweight, can fit into small, irregular spaces, and can handle being bent repeatedly.

Rigid-Flex PCBs

Combining the best of both rigid and flexible PCBs, these are great for devices that need both stability and flexibility, like smartphones, cameras, and medical devices. They save space, reduce the need for connectors and interconnections, and improve reliability.

High-Frequency PCBs

Designed to operate at frequencies above 1 GHz, these are used in communication systems, microwave technology, and high-speed devices. They provide low signal loss and high performance, making them crucial for advanced communication technologies.

Ceramic PCBs

Using ceramic as the substrate material, these PCBs offer excellent thermal conductivity and stability. They’re perfect for high-power applications and environments with extreme temperatures, like LED lighting, power electronics, and aerospace systems. Ceramic PCBs ensure reliable performance in harsh conditions.

Metal Core PCBs

Featuring a metal core, usually aluminum or copper, these PCBs improve heat dissipation. They’re used in high-power applications where efficient thermal management is crucial, such as LED lighting, power supplies, and automotive electronics.

Special PCBs

Bus Bar PCBs

These integrate bus bars for high-current applications, ensuring efficient power distribution and minimal voltage drop. They’re used in heavy-duty power supplies, electric vehicles, and industrial machinery. Bus bar PCBs provide robust and reliable connections for high-power systems.

What is a PCB Board?

Heavy Copper PCBs

With thicker copper layers, typically 3 ounces per square foot or more, these PCBs can handle higher currents and enhance thermal management. They’re used in power distribution, automotive, and industrial applications where durability and performance are critical. Heavy copper PCBs ensure reliable operation under high-stress conditions.

What is a PCB Board?

HDI (High-Density Interconnect) PCBs

These feature finer lines and spaces, smaller vias, and higher connection pad density. They’re used in advanced electronics like smartphones, tablets, and medical devices where space and performance are paramount. HDI PCBs enable miniaturization and improved electrical performance.

Extra Thin PCBs

Designed with minimal thickness, these PCBs are perfect for fitting into compact and lightweight devices. You’ll find them in flexible displays, wearables, and miniaturized electronic gadgets. Extra thin PCBs allow for innovative design solutions and space-saving configurations.

What is a PCB Board?

RF (Radio Frequency) PCBs

Optimized for high-frequency signals, these are used in communication devices, antennas, and microwave applications. They’re designed to minimize signal loss and interference, ensuring optimal performance in wireless communication systems.

High Tg PCBs

These have a high glass transition temperature, making them suitable for high-temperature environments. Used in automotive, aerospace, and industrial applications, high Tg PCBs maintain structural integrity and performance at elevated temperatures.

Impedance Control PCBs

These are designed to maintain consistent impedance for high-speed signal transmission. They’re used in communication devices, high-speed digital circuits, and advanced computing systems. Impedance control PCBs ensure signal integrity and reduce signal loss and reflection.

What is a PCB Board?

Why Are PCB Boards So Expensive?

Material Quality

High-grade materials like FR4 (fiberglass), ceramics, and high-quality copper foil are used to ensure durability and performance. These materials are essential for withstanding environmental stress and ensuring reliable operation, but they are expensive. For example, ceramic substrates can cost up to 10 times more than standard FR4 materials due to their superior thermal conductivity and electrical properties.

Complexity of Design

Multi-layer PCBs and advanced designs such as HDI (High-Density Interconnect) boards require complex manufacturing processes. The process involves precise alignment of layers and sophisticated techniques like laser drilling for micro-vias. The added complexity increases the production costs significantly. For instance, a standard 4-layer PCB might cost $50 per square meter, while a 12-layer HDI PCB could cost over $200 per square meter.

Precision and Technology

Manufacturing high-precision PCBs involves advanced machinery for etching, drilling, and plating. This machinery requires significant investment, and the skilled labor needed to operate it adds to the cost. The precision required in the production process ensures that the PCBs meet exacting standards, crucial for high-performance applications. A single advanced PCB drilling machine can cost upwards of $500,000.

Volume of Production

Smaller production runs generally have higher costs per unit because the setup and tooling expenses are spread over fewer units. For example, a low-volume production run of 10 PCBs might cost $100 per board, whereas a high-volume run of 10,000 boards might reduce the cost to $10 per board due to economies of scale.

Testing and Quality Assurance

Rigorous testing, including electrical, thermal, and functional tests, ensures that the PCBs meet strict performance standards. This testing process is vital to ensure reliability, especially in critical applications like medical devices and aerospace. Quality assurance processes can add 20-30% to the overall production cost, but they are essential for maintaining high standards.

What is the Difference Between PCBA and PCB Board?

The terms PCB and PCBA are often used interchangeably, but they refer to different stages of the board’s life cycle. The PCB is the bare board itself, with no electronic components attached. It consists of a non-conductive substrate, copper traces, solder mask, and silkscreen. A PCB serves as the foundation for assembling electronic components.

On the other hand, a PCBA (Printed Circuit Board Assembly) is a PCB that has undergone the assembly process, where all necessary electronic components like resistors, capacitors, diodes, and integrated circuits are soldered onto the board. Essentially, a PCBA is a functional circuit board ready for use in electronic devices. The transition from a PCB to a PCBA involves component placement, soldering, and quality testing, transforming the bare board into an operational assembly. Below is a typical PCBA product for your reference.

What is a PCB Board?

What is PCB Board Common Use?

PCB boards are existing in everywhere what we live, for example, the global smartphone market, which relies heavily on PCBs, was valued at approximately $520 billion in 2020. Here are some common applications that PCB used in:

Automotive Industry

In the automotive sector, PCBs are used in engine control units, infotainment systems, and advanced driver-assistance systems (ADAS). These applications enhance vehicle performance, safety, and connectivity.

Medical Devices

PCBs are integral to medical devices such as diagnostic equipment, patient monitoring systems, and implantable devices. They ensure precise and reliable operation, which is critical for patient safety and effective treatment.

Industrial Applications

PCBs are used in control systems, machinery, and power distribution units in industrial settings. They provide robust and durable solutions capable of withstanding harsh conditions and continuous operation.


In telecommunications, PCBs are essential in routers, switches, and communication devices, ensuring efficient and reliable data transmission. As the demand for faster and more reliable communication networks grows, so does the need for high-quality PCBs.

Why Are Circuit Boards Green?

The characteristic green color of most PCBs comes from the solder mask, a protective layer applied over the copper traces to prevent oxidation, short-circuiting, and to protect the board during soldering.

The green color is traditional, largely due to historical reasons and practical benefits. Green solder mask provides a good contrast against the white silkscreen and the shiny copper traces, making it easier for technicians to inspect and identify components during assembly and troubleshooting. Additionally, green solder mask was one of the first colors to be developed and standardized in the industry, leading to its widespread adoption. However, PCBs are not limited to green; they can also be found in other colors such as red, blue, black, and white, depending on the specific requirements and aesthetic preferences of the project. The choice of solder mask color does not affect the performance of the PCB, but green remains popular due to its well-established manufacturing process and visual advantages.

How to Get Started with Best Technology?

Here at Best Technology, we are experienced in designing all types of PCBs, including standard rigid PCBs, special PCBs, and irregular PCBs. We can design and develop PCBs according to customer specification and offer suggestions on the right materials for your project.

We provide the full series of PCB manufacturing, from the initial PCB design, PCB layout, to custom PCB fabricate, PCB assembly, box building and so forth. By the way, we have our own factory in Vietnam, that means we can ship out the PCBs directly from Vietnam.

Welcome to contact us when you want to get a quote!

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What is FR4 material in PCB? – Best Technology
Friday, July 12th, 2024

FR4 is a commonly used material in the printed circuit boards (PCBs) manufacturing. If you’re in the electronics field, you’ve likely heard of it. It is the footstone of a circuit board, provides good mechanical strengthen and electrical insulation properties. Today, we will share informational about FR4 material, its types, advantages and alternatives. Keep reading if you are interested in.

What is FR4 material in PCB? - Best Technology

What does FR4 stand for?

FR4 stands for “Flame Retardant 4”, also called FR-4 Epoxy Glass Cloth by PCB manufacturers. It is not a material name, but a material grade, so there are many types of FR-4 grade materials used in general circuit boards. But most are composites made with so-called Tera-Function epoxy resins plus fillers and glass fibers. FR4 is made from woven glass-reinforced epoxy resin. The typical composition of FR4 includes approximately 60% glass fabric and 40% epoxy resin by weight.

What is FR4 material in PCB? - Best Technology

This composite material is known for its high mechanical strength and flame-retardant properties. The “4” in FR4 signifies the level of flame retardancy. It means the material is resistant to catching fire, which is critical in preventing electrical fires in electronic devices.

What are the classifications of FR4 materials?

FR4 materials are classified based on various properties and specifications to cater to different applications and requirements. These classifications help in selecting the right type of FR4 material for specific PCB needs. Here are the primary classifications of FR4 materials:

1. Standard FR4

Standard FR4 is the most commonly used classification. It offers a good balance of electrical insulation, mechanical strength, flame retardancy, and cost-effectiveness. Standard FR4 materials have a glass transition temperature (Tg) typically around 130°C to 140°C. They are suitable for general-purpose PCBs used in consumer electronics, industrial controls, and telecommunications equipment.

2. High Tg FR4

High Tg FR4 materials are designed for applications requiring higher thermal performance. These materials have a higher glass transition temperature, usually above 170°C. High Tg FR4 is used in applications where the PCB is exposed to higher temperatures, such as automotive electronics, aerospace, and high-power devices. The increased Tg provides better stability and performance at elevated temperatures. This is the high Tg FR4 PCB that we made before.

3. Low Dk FR4

Low Dk (Dielectric Constant) FR4 materials are used in high-frequency applications where signal integrity is crucial. So, we called it as “High-frequency FR4”. These materials have a lower dielectric constant, which reduces signal loss and improves signal transmission. Low Dk FR4 is often used in RF and microwave circuits, where maintaining signal integrity is essential.

4. High CTI FR4

High CTI (Comparative Tracking Index) FR4 materials have an improved resistance to electrical tracking. These materials are used in applications where the PCB is exposed to high voltages and harsh environments. High CTI FR4 provides better insulation and reduces the risk of electrical failure due to tracking.

5. Halogen-Free FR4

Halogen-free FR4 materials are designed to meet environmental and safety requirements by eliminating halogens. Which can be harmful if released during PCB manufacturing or disposal. These materials are used in applications where reducing environmental impact is a priority. Halogen-free FR4 offers similar performance to standard FR4 but without the use of halogenated flame retardants.

Benefits of using FR4 as PCB material

  • Excellent Electrical Insulation
  • High Mechanical Strength
  • Flame Retardancy
  • Moisture Resistance
  • Cost-Effectiveness
  • Thermal Stability
  • Ease of Fabrication

Properties of FR4 material

Vertical flexural strengthNormal State: E-1/150, 150±5℃≥340Mpa
Parallel layer impact strength≥230KJ/m
Insulation resistance after water immersion (d-24/23)≥5.0×108Ω
Vertical electrical strength≥14.2MV/m
Parallel layer breakdown≥40KV
Relative Dielectric Constant (50hz)≤5.5
Relative Dielectric Constant (1mhz)≤5.5
Dielectric Loss Factor (50hz)≤0.04
Dielectric Loss Factor (1mhz)≤0.04
Water Absorption (D-24/23, 1.6mm Thickness)≤19mg

What is the Difference Between IMS and FR4 PCB?

IMS (Insulated Metal Substrate) and FR4 PCBs serve different purposes. IMS PCBs are designed for applications requiring efficient heat dissipation. They have a metal base layer that helps manage heat more effectively than FR4. This makes IMS ideal for high-power applications like LED lighting.

IMS insulated metal substrate PCB

On the other hand, FR4 PCBs are used in general electronic applications due to their balance of performance and cost. While IMS excels in thermal management, FR4 is preferred for its electrical properties and versatility.

What is the Cost of FR4 PCB Per Square Inch?

The cost of an FR4 PCB can vary based on several factors. These include the board’s thickness, the number of layers, and the complexity of the design. On average, the cost per square inch of FR4 PCB ranges from $0.10 to $0.50. However, this is a rough estimate. For a precise quote, it’s best to contact PCB manufacturers with your specific requirements. If you are searching for a PCB supplier, Best Technology is here to waiting for you.

Why is Rogers Better Than FR4 Material?

Rogers material is often considered superior to FR4 in high-frequency applications. Here are some key reasons why Rogers might be chosen over FR4.

  1. Lower Dielectric Loss
  2. Higher Thermal Conductivity
  3. Improved Dimensional Stability
  4. Consistent Dielectric Constant
  5. Superior Performance in High-Frequency Applications
  6. Compliance with Stringent Industry Standards

What Material is Similar to FR4?

Several materials are similar to FR4 and can be used as alternatives. One such material is CEM-1, which is also a composite material made from epoxy and fiberglass. It offers good mechanical strength and electrical properties but is less flame retardant than FR4.

Another alternative is polyimide, known for its excellent thermal stability and flexibility. It is often used in applications requiring high-temperature resistance. However, polyimide is more expensive than FR4. For specific applications, materials like PTFE (Teflon) can also be considered, especially in high-frequency applications.


1. Can FR4 be used in high-temperature applications?

FR4 can withstand moderate temperatures, but for high-temperature applications, materials like polyimide are preferred.

2. Is FR4 environmentally friendly?

FR4 is not biodegradable but can be recycled to some extent. Proper disposal and recycling methods should be followed.

3. How does the thickness of FR4 affect PCB performance?

The thickness of FR4 can impact the board’s mechanical strength and thermal dissipation. Thicker boards offer more durability but may also increase the cost.

4. Are there any disadvantages to using FR4?

FR4 has limitations in high-frequency and high-temperature applications. It is also less effective in thermal management compared to materials like IMS.

5. Can FR4 PCBs be used in flexible circuits?

FR4 is rigid and not suitable for flexible circuits. For flexible applications, materials like polyimide are used. But recently, Best Technology developed a new product called “semi-flexible FR4 PCB”, its flex area is made by FR4 material.

  • Is FR4 RoHS Compliant?

Yes, FR4 is RoHS compliant. This means that it meets the regulations set by the European Union to limit the use of specific hazardous materials found in electrical and electronic products.

  • What is FR4 Tg?

The glass transition temperature (Tg) of FR4 is a critical property that indicates the temperature at which the material transitions from a hard, glassy state to a soft, rubbery state.

Best Technology excels not only in PCB and assembly manufacturing, but also in offering top-quality PCB design services. Our professional engineering team is ready to support your innovation across various industries, including communications, healthcare, industrial, and consumer electronics. We welcome all the questions or inquiries from you.

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How to Make a BOM?
Thursday, July 11th, 2024

If you are familiar with SMT or PCB assembly process, you may know BOM file. It is an important element in the SMT process. Creating BOM is a crucial step in the manufacturing process, especially for PCBs. A BOM serves as a comprehensive list of all the parts, components, and materials needed to build your product. It ensures that everyone involved in the production process is on the same page, reducing the risk of errors and delays. Today, Best Technology would like to introduce BOM and giving you a guide to create a BOM file step by step.

How to Make a BOM?

What is a Bill of Materials (BOM)?

A Bill of Materials (BOM) is a detailed list of all the parts, components, and materials needed to manufacture a product. In PCB manufacturing, a BOM outlines every item required to assemble a PCB, including quantities, part numbers, and descriptions. It serves as a guide to ensure that the manufacturing process runs smoothly and that no crucial components are missing.

Types of Bill of Materials

There are several types of BOMs used in different stages of production. Each type serves a specific purpose and provides unique details to streamline processes and ensure accuracy. Here are the primary types of BOMs:

  • Engineering BOM

This type of BOM is creating during the design phase. It lists all the parts and components designed by the engineering team, including specifications and relationships as intended in the final product. And of course, it mainly used by design engineers to communicate the product structure and details to manufacturing teams.

  • Manufacturing BOM (Formal)

It is a formal BOM files that used in the assembly phase. Different with engineering BOM, it includes additional details necessary for manufacturing, such as packaging, handling instructions and assembly details. And some special instructions.

  • Sales BOM

Sales BOM is used by sales teams and includes information relevant to the sales process, such as pricing and availability. It helps in providing accurate quotes, managing customer expectations, and handling sales orders efficiently.

What Should Include in an Effective Bill of Materials?

An effective BOM should be detailed, accurate, and easy to understand. It should include all the details of components and indicated revisions. As a 18 years expertise in PCBA production, we summarized the key elements that should be included in the BOM.

  • Component details

It should include all the components and their detailed information, such as names, part numbers (PN), and descriptions for each part.

  • Quantity (QTY)

The exact quantity of each component required for the product. Accurate quantities can prevent shortages and overstocking.

  • Foot print

It is the package of each component, helping to ensure the correction of part.

  • Reference Designators

Unique identifiers that match each component to its specific location on the product layout. These are essential for assembly and troubleshooting.

  • Manufacturer Information

Manufacturer information, including the manufacturer name of components and manufacturer part number. It helps to ensure correct parts are sourced. And convenient for alternative part sourcing if it is shortage.

  • Supplier information (Optional)

It means the name of the supplier or distributor. The part number used by the supplier, which may differ from the manufacturer’s part number.

  • Assembly instructions

Any special notes for assembly such as DNF remark, and version control to track revisions should also be included. Additionally, cost information helps in budgeting, and lifecycle status information helps plan for component availability and avoid discontinued parts.

How to Make a PCB Bill of Materials (BOM)?

Creating a PCB BOM is a systematic process that involves compiling all the necessary information about each component required for the assembly of the PCB. Here’s a detailed guide on how to create a PCB BOM:

  • Open a Blank Spreadsheet

Use software like Microsoft Excel or Google Sheets to start with a blank spreadsheet. They are common to use, offering flexibility and ease of use for creating and managing BOMs.

  • Define Columns

Set up your spreadsheet with appropriate column headers. Common headers include:

  • Part Number
  • Component Name
  • Quantity
  • Reference Designator
  • Manufacturer
  • Manufacturer Part Number
  • Supplier
  • Supplier Part Number
  • Description
  • Package Type
  • Cost
  • Notes
  • Input Data

Enter the required details for each component under the appropriate headers. Please be make sure that all information is accurate and complete. This may involve referencing design files, datasheets, and supplier catalogs. If it is incorrect, then it needs a lot of time to find out and revise the errors, resulting in schedule delay.

  • Use Formulas

Utilize Excel formulas to automate calculations, such as summing total quantities or calculating costs. This helps in reducing manual errors and saves time.

  • Format for Clarity

Use cell formatting options to highlight important information and ensure the spreadsheet is easy to read. For example, you can use bold text for column headers, color coding for different component types, and borders to separate sections.

  • Include Version Control

Add a version control section to your BOM to track revisions and updates. This can be a simple row at the top or bottom of the spreadsheet, indicating the version number, date of revision, and a brief description of changes.

How to Make a BOM?
(BOM file reference)
  • Save and Update

Save your BOM and update it regularly to reflect any changes in the design or component availability. Regular updates ensure that the BOM remains accurate and up-to-date, preventing issues during production.

  • Review and Verify

Have multiple team members review the BOM for accuracy. Cross-check all component details, quantities, and part numbers against the design files. Verification helps catch errors early and ensures the BOM is reliable.

  • Communicate with Suppliers:

Maintain open communication with suppliers to confirm component details and availability. This ensures that you can source the correct parts and avoid delays in the production process.

How Can I Optimize My BOM for PCB Assembly?

Sometimes, a simple BOM is not good to process PCB assembly process, and manufacturers may need to spend a lot of time to optimize it, make into convenient for manufacturing. If you are a layman, here are some steps to help you in optimizing your BOM file.

First, it’s a good idea to standardize components where possible. Using standard parts that are readily available from multiple suppliers can simplify procurement and reduce costs. This approach minimizes the risk of shortages and ensures you can get parts quickly and affordably. Also, make sure all entries in your BOM are clear and concise to avoid confusion during assembly. Double-checking part numbers and quantities against design files is crucial to prevent errors that could lead to rework or delays.

Building strong relationships with your suppliers is another key factor. Good communication with suppliers helps ensure reliable component availability and keeps you informed about any changes in lead times or part availability. Regularly updating your BOM to reflect any design changes or component availability issues is essential. Keeping your BOM current and accurate prevents last-minute surprises during assembly.

How to Make a BOM?

What Common Mistakes Should I Avoid When Creating a PCB BOM?

Avoiding common mistakes in BOM creation can save time and reduce errors. Here are some pitfalls to watch out for:

  • Incomplete information – ensure all necessary details are included for each component.
  • Incorrect quantities – double-check quantities to avoid shortages or excess inventory.
  • Outdated data – keep the BOM updated with the latest design changes and component information.
  • Ambiguous descriptions – provide clear and precise descriptions to prevent confusion.
  • Lack of version information – implement version control to track changes and ensure the correct BOM version is used.

Creating an effective and accurate PCB BOM is essential for smooth manufacturing and assembly. By following best practices and using the right tools, you can ensure your BOM is comprehensive, clear, and up-to-date, ultimately leading to a successful PCB production process.

Best Technology is an expert in SMT and PCB assembly, we have more than 18 years in this industry, that can offer you a best experience of PCBA solution. In our facotry, we have advanced equipment like full auto pick and place machine, online dual AOI, X-ray, 3D SPI, nitride reflow oven and three-proof paint machine. So that we can ensure the fast lead time and high quality of your PCBA products. Reach us to get a instant quote!

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What is Tg meaning in FR4 PCB? – Best Technology
Wednesday, July 10th, 2024

In the world of printed circuit boards (PCBs), understanding material properties is crucial. One such property is Tg, or glass transition temperature. For FR4 PCBs, knowing what Tg means can significantly impact design and performance. In this blog, we’ll explore what Tg is, how it’s measured, its importance, and other related questions.

What Does Tg Mean in PCB Manufacturing?

Tg stands for glass transition temperature. It refers to the temperature at which a polymer material, such as the resin in a PCB substrate, transitions from a hard, glassy state to a softer, rubbery state.

For the circuit board, the ‌Tg value reflects the highest temperature it can withstand. When the temperature exceeds Tg values, ‌ the molecular structure of the circuit board material will be changed, ‌ lead to changes in its physical properties. Such as mechanical strength, size stability, adhesive, water imbibition, thermal expansion, etc. ‌Therefore, the level of TG value of the PCB directly affects the stability and high temperature resistance of the circuit board.

What is Tg meaning in FR4 PCB? - Best Technology

In the high temperature environment, if the TG value of the circuit board is too low, it is easy to cause PCB deformation, fracture, cracking and other problems, affecting the reliability and life of the printed circuit board. If the TG value of the circuit board is too high, the PCB is easy to become hard and brittle, affecting the processability and flexibility of the circuit board.

How is Tg Measured in FR4 Materials?

Accurate measurement of Tg is crucial for ensuring the performance and reliability of FR4 PCBs. Knowing the exact Tg helps in selecting the appropriate material for specific applications, particularly those involving high temperatures and thermal cycling. Using materials with a Tg well above the operating temperature ensures the PCB will maintain its mechanical and electrical properties under expected conditions.

The primary method for measuring Tg in FR4 materials is by differential scanning calorimetry (DSC). It involves heating a small sample of the material at a controlled rate, typically between 10°C to 20°C/min. As the sample heats, the DSC measures the heat flow into the material and records it as a thermogram. The Tg is identified as the temperature where there is a noticeable change in heat capacity, appearing as a step or inflection point on the thermogram. DSC is widely used because it provides precise and reliable Tg measurements.

What is Tg meaning in FR4 PCB? - Best Technology

Additionally, Dynamic Mechanical Analysis (DMA) and Thermomechanical Analysis (TMA) also can be used to measure the Tg value.

Why is Glass Transition Temperature Critical in PCBs?

Glass transition temperature is critical because it affects the thermal and mechanical properties of the PCB. If a PCB operates near or above its Tg, it can experience issues like delamination, warping, and electrical failure. Here are some benefits of Tg.

  • Thermal stability

One of the main reasons is its role in determining thermal stability. During operation, PCBs are subjected to varying temperatures due to power dissipation from electronic components and environmental conditions. Make sure the Tg of the PCB material is well above the maximum operating temperature, it helps maintain mechanical stability and reliable performance under thermal stress.

  • Mechanical Strength

The Tg value also affects the mechanical strength and durability of the PCB. Below the Tg, the material is rigid and can withstand mechanical stress without significant deformation. This rigidity is essential for maintaining the structural integrity of the PCB, especially during assembly processes like soldering, where the board is subjected to mechanical and thermal stresses.

  • Thermal Management

Thermal management is very important to electronics, especially for those miniaturized electronic devices. If the PCB itself has good thermal management, then designers no need to install heatsink or coolers. Materials with higher Tg values exhibit lower coefficients of thermal expansion (CTE), meaning less expansion and contraction with temperature changes. 

  • Application-specific requirements

Different applications have varying thermal and mechanical requirements. High-performance computing, automotive, aerospace, and industrial electronics often operate in environments with high temperatures and thermal cycling. For these applications, using PCB materials with appropriate Tg values is crucial.

What is the Typical Tg Value for Standard FR4 PCBs?

Standard FR4 materials generally have Tg values in the range of 130°C to 140°C. For high-performance applications, materials with higher Tg values are necessary. The table below lists some common high Tg materials used in PCB manufacturing, along with their Tg values and characteristics.

MaterialTg Value (°C)CharacteristicsApplications
ISOLA IS410180Excellent thermal and mechanical propertiesHigh-reliability applications
Nanya NP-175175High thermal stability, good mechanical strengthAutomotive, industrial electronics
Shengyi S1000H170Cost-effective, widely usedConsumer electronics, industrial applications
Ventec VT-47170High Tg and low CTEHigh-density interconnect (HDI) PCBs
Rogers 4350B280Extremely high Tg, excellent thermal stabilityRF and microwave applications
(Common used high Tg materials)

Can You Explain the Difference Between Tg and Td in PCBs?

Tg and Td (decomposition temperature) are two different thermal properties. Unlike the reversible physical change associated with Tg, decomposition is an irreversible chemical process. At Td, the polymer chains in the material break down, leading to a loss of structural integrity and release of volatile compounds. Key points about Td include:

1. Chemical Stability

Td represents the upper thermal limit of a material’s chemical stability. Exceeding Td results in the breakdown of the polymer structure, rendering the material unsuitable for further use.

2. Material Selection

Knowing the Td helps in selecting materials for high-temperature applications. A material’s Td should be well above the maximum operating temperature to prevent degradation.

What is Tg meaning in FR4 PCB? - Best Technology

3. Safety and Reliability

Operating a PCB above its Td can result in catastrophic failure, including charring, delamination, and loss of electrical performance. The operating temperature remains below Td is critical for safety and reliability.

How Do You Choose the Right Tg Value for Your PCB Design?

Choosing the right Tg value depends on the operating environment and thermal demands of your application. Consider factors such as the maximum operating temperature, the thermal cycling the PCB will undergo, and the mechanical stresses it will face. Consulting with material suppliers and using simulation tools can help make an informed decision. According to our 18 years experience in PCB, we summarized a recommend Tg value for each application. Hope this is useful for you guys.

  • Consumer electronics

If your PCB will be used in standard consumer electronics, just like smartphones and tablets, a Tg value of around 130°C to 140°C is typically sufficient. These devices generally do not encounter extreme temperatures or thermal cycling.

  • Automotive applications

Automotive PCBs are always exposed to high temperatures and significant thermal cycling. A Tg value of 170°C or higher is recommended to ensure reliability and performance under the hood. So, Rogers material is good for this kind of PCB.

  • Aerospace and defense

Applications in aerospace and defense require materials that can withstand extreme temperatures and harsh environments. High Tg materials with values of 180°C or more are often used to meet these stringent requirements.

  • Industrial Electronics

Industrial environments can vary widely, but generally, high Tg materials are preferred due to the exposure to high temperatures and mechanical stress. A Tg value of at least 150°C to 170°C is advisable.

Best Technology is a well-known PCB and PCBA assembly provider in Asia and Vietnam. We have a large facility for handling low-medium to mass production PCBs, and supporting for various kinds of custom PCBs. Some special PCBs are available here, like bus bar PCB for new energy vehicles, heavy copper PCB for high power and high current PCBs, ceramic PCBs for harsh environments, extra thin PCB, RF PCB, microwaves PCB, IC substrate PCB and so on.

For more information, please do not hesitate to contact us.

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India Customer Visit in Best Technology
Thursday, July 4th, 2024

On July 3rd, 2024, we had India customers visit our office and factory. All our staff of our customer warmly welcome the guest from afar.

Our sales manager Peter, along with Connie and Marina, gave a detailed introduction to our main business and product expertise. They talked about our strict quality control, careful selection of PCB board materials, advanced production equipment, and mature manufacturing processes. Our guests seemed quite impressed with how thorough we are in ensuring top-notch quality.

PCB product introduction

Actually, we’ve been working with this customer for several years now, and it’s been a fantastic journey of building trust and collaboration. This visit was a great chance to dive into a new PCB project and show off our latest innovations, including electric heating films, ceramic PCBs, and bendable aluminum PCBs.

When checking the sample books, the customers specially mentioned the blind vias and checked the related products for many times. It looks like they are extremely interested in this technology.  You know, blind vias, buried vias, through hole vias, micro vias and thermal vias are always our strengthens.

PCB samples sharing

Next day, Connie will be taking our guests on a tour of our metal dome and dome array factory. It’s always exciting to show our partners the heart of our operations and let them see firsthand the dedication and precision that goes into our work.

Metal dome project talking

Best Technology is a one-stop PCB and PCBA service provider in China and Vietnam. “High mix, Low-Middle Volume, High Quality and Fast Delivery” is our advantages. Custom PCBs available in our company as well. You can get high-quality PCB board and PCBA at a very transparent price. For more information, feel free to contact us at any time.

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PWB Vs. PCB: What Are the Manufacturing Process Differences?
Thursday, July 4th, 2024

In our daily life, electronic devices are existing everywhere. And there are many people know the “PCB” nowadays, while very less people know the “PWB”. Unless you’ve been in the PCB business for more than 20 years.

Actually, PWB is another term of circuit board, and it was used commonly before the year 1999. But with the development of electronics, it was replaced by PCB gradually. You want to know more about it? In this article, we will answer it for you. Deeply explain their definitions, manufacturing process, applications and the key differences between PCB and PWB.

PWB Vs. PCB: What Are the Manufacturing Process Differences?

What is A Printed Circuit Board (PCB)?

A Printed Circuit Board is a fundamental component in modern electronics, providing the physical and electrical connections for various electronic components. It consists of multiple compositions, including a non-conductive substrate, conductive pathways, and insulating layers, which facilitate the complex circuitry required in contemporary devices. A PCB can be made into single sided PCB, double sided PCB and multilayer PCB.

PCBs are integral to the functionality of a wide range of electronic products, from consumer gadgets like smartphones and computers to industrial machinery, medical devices, and aerospace systems. The advanced design and manufacturing processes involved in PCB production ensure high reliability and performance, making them essential in virtually all electronic applications.

PWB Vs. PCB: What Are the Manufacturing Process Differences?

Basic manufacturing process of PCB

Design and Layout

PCBs are designed using sophisticated computer-aided design (CAD) software. Designers create detailed layouts, specifying the placement of components, conductive pathways, and vias (interlayer connections). The design is converted into Gerber files, a standard format for PCB fabrication that contains all the necessary information for manufacturing. These files are essential for ensuring precision and accuracy during the manufacturing process.

Material Preparation

The substrate, typically FR4 (fiberglass epoxy laminate), is prepared. FR4 is known for its excellent mechanical strength and thermal stability, making it an ideal base material for PCBs. Copper sheets are laminated onto the substrate, which will form the conductive pathways after the etching process. This preparation stage is crucial for creating a reliable foundation for the PCB.

Printing the Circuit Pattern

A photoresist, a light-sensitive material, is applied to the copper-clad substrate. The board is exposed to ultraviolet (UV) light through a mask that defines the circuit pattern. The UV light hardens the photoresist in the exposed areas. The board is then developed in a chemical solution that removes the unexposed photoresist, revealing the copper to be etched away. This step accurately transfers the circuit design onto the board.


The board is immersed in an etching solution, commonly ferric chloride or ammonium persulfate, which removes the unprotected copper, leaving only the desired circuit pattern. This etching process is crucial for defining the conductive pathways on the PCB, ensuring that the correct connections are made according to the design specifications.


Precision drilling machines are used to create holes for through-hole components and vias. These holes are then cleaned to remove any debris that could affect electrical connectivity. Drilling is a critical step in the PCB manufacturing process as it ensures proper placement and connection of components across different layers of the board.


The drilled holes are plated with copper to create electrical connections between the layers, which is especially important for multilayer PCBs. Additional layers of plating, such as nickel or gold, may be applied to improve conductivity and protect against oxidation. This plating process enhances the durability and performance of the PCB.

Solder Mask Applying

A solder mask is applied to protect the copper traces from oxidation and prevent solder bridges between closely spaced solder pads. The solder mask is exposed to UV light and then developed to reveal the solder pads. This layer not only protects the PCB but also improves its appearance and reliability.

Silkscreen Printing

A silkscreen layer is printed on the board to add text, component labels, and other identifiers. This layer helps in the identification and assembly of components, making it easier for technicians to work with the PCB during the manufacturing and repair processes.

Surface Finishing

Generally, a layer of surface finishing is coated on the PCB to protect its surface, it also called surface treatment. The common surface treatments are HASL-LF, ENIG, ENEPIG, OSP, Immersion Silver/Tin. Of course, different treatment offers different function, like OSP is to protect surface from oxidation, HASL-LF provides a good solderability, ENEPIG make sure the chemistry corrosion. Choose a suitable one according to your specific demands.

Assembly and Testing

Components are placed on the board using automated pick-and-place machines, and soldered using techniques like reflow soldering for surface-mount devices (SMD) and wave soldering for through-hole components. The finished PCB undergoes various tests, such as automated optical inspection (AOI), electrical testing, and functional testing, to ensure quality and performance. Want see the whole manufacturing process of a multilayer PCB, click here: Manufacturing Process of Multi-layer PCB.

PWB Vs. PCB: What Are the Manufacturing Process Differences?

What is the definition of Printed Wiring Board (PWB)?

A Printed Wiring Board is a term historically used to describe a type of circuit board that focuses primarily on the layout and wiring of electronic connections rather than the overall circuit functionality. PWBs emphasize the physical arrangement of conductive paths to connect various components but do not necessarily include all the integrated features found in modern PCBs.

PWB Vs. PCB: What Are the Manufacturing Process Differences?

This term was more prevalent during the earlier stages of electronic development, where the primary concern was establishing reliable electrical connections. As technology advanced, the term PCB became more common, reflecting the expanded capabilities and comprehensive role of these boards in forming complete electronic circuits. Despite being less common today, understanding the term PWB is crucial for historical context and certain niche applications.

How to Manufacture A Printed Wiring Board (PWB)?

Design and Layout

PWBs typically have simpler designs focused on wiring patterns rather than complex circuitry. In some cases, the layout may be done manually or using basic design software.

Material Preparation

Simpler substrates such as phenolic or epoxy resins may be used for PWBs. Copper sheets are laminated onto the substrate to form the conductive pathways. These materials are cost-effective and suitable for applications where advanced performance characteristics are not required.

Printing the Wiring Pattern

Similar to PCBs, a photoresist is applied to the copper-clad substrate. The board is then exposed to UV light through a mask and developed to reveal the copper to be etched away. This process creates the wiring pattern necessary for connecting electronic components.


The board is immersed in an etching solution to create the wiring pattern. This step is straightforward compared to the more intricate etching processes used in PCB manufacturing, reflecting the simpler requirements of PWBs.


Holes for through-hole components are drilled, but the process may not require the precision needed for complex PCBs. This basic drilling process is adequate for the less demanding applications of PWBs.

Plating (if necessary)

Plating is done to ensure electrical connectivity but may not involve advanced techniques like those used for multilayer PCBs. It suffices for the simpler construction of PWBs.

Solder Mask Application

A basic solder mask may be applied to protect the wiring pattern. This layer provides sufficient protection for the relatively simple designs of PWBs, preventing short circuits and oxidation.

Silkscreen Printing

A simple silkscreen layer may be added for component identification. This helps in the assembly process but does not require the detailed labeling often necessary for PCBs.

Assembly and Testing

Components are manually or semi-automatically placed on PWBs and soldered using standard techniques. Basic electrical testing is conducted to ensure functionality. This simpler assembly and testing process aligns with the less complex nature of PWBs.

pcb assembly

Which Kind of Materials used in PCB and PWB?

Substrate Materials

FR4 (fiberglass epoxy laminate) is the most common substrate material for PCBs due to its excellent mechanical strength and thermal stability. Phenolic resin, used in PWBs for simpler applications, is less durable and has lower thermal stability compared to FR4, but it is cost-effective and suitable for basic electronic devices. Polyimide is used for flexible PCBs due to its high flexibility and thermal resistance, making it ideal for applications requiring bending and flexing, such as wearable electronics and flexible displays.

Conductive Materials

Copper is the primary conductive material for both PCBs and PWBs. It is used to create the conductive pathways and pads, providing excellent electrical conductivity and reliability. Gold, nickel, and silver are used for plating to enhance conductivity and protect against oxidation, primarily in PCBs. These materials improve the durability and performance of the PCB by providing a reliable contact surface for soldering and component connections.

Insulating Materials

Prepreg, a fiberglass cloth impregnated with resin, is used in multilayer PCBs to bond the layers together. Prepreg provides mechanical strength and electrical insulation between the layers. Dielectric materials are used between layers in multilayer PCBs to provide electrical insulation, maintaining signal integrity and preventing short circuits.

Solder Mask Materials

Liquid Photo Imageable (LPI) solder mask is the most common type used in PCBs, providing excellent protection and durability. LPI solder masks are applied using a photolithographic process, ensuring precise coverage and protection. Dry film solder mask is used for simpler applications and PWBs. This type of solder mask is less expensive and easier to apply but may not offer the same level of protection as LPI solder masks.

Key differences between PCB and PWB

FeaturePCB (Printed Circuit Board)PWB (Printed Wiring Board)
Design and LayoutDesigned using sophisticated CAD tools for complex circuitry, including detailed simulation and optimization.Simpler designs focused on wiring patterns, often done manually or with basic software.
Layer CountCan have multiple layers (e.g., double-sided, multilayer) to support intricate circuit designs.Generally single or double-sided, less commonly multilayer.
Component TypesSupports surface-mount technology (SMT) and through-hole technology (THT) components.Primarily supports through-hole technology (THT) components.
Signal IntegrityDesigned to maintain high signal integrity, minimizing electrical noise and interference.Basic signal integrity management, sufficient for simple applications.
Flexibility and RigidityIncludes both rigid and flexible PCBs, allowing for a wide range of applications.Typically rigid, not commonly used in flexible applications.
Terminology and UsageUniversally used in the industry to refer to boards that integrate all necessary components to form complete circuits. Also called “bare board”.Universally used in the industry to refer to boards that integrate all necessary components to form complete circuits.
Industry StandardsRecognized by standards organizations like IPC, IEC, and ANSI with specific performance and quality criteria.Covered under broader standards but with fewer specific guidelines due to limited modern use.
Cost and EfficiencyHigher cost due to advanced materials and processes, offering superior performance and reliability.More cost-effective for simple applications, but with limited performance and reliability.
ApplicationsUsed in consumer electronics, industrial equipment, medical devices, aerospace, and defense.Historically used in simpler electronic devices and early computers, still relevant in niche applications.
(Summary Differences: PCB VS PWB)

Other Terms Related to PWB and PCB

Based on the PCB and PWB, you may still hear about CCA, PCA, PWA during the PCB working. These terms are also related to printed circuit board. Here is a detailed explanation of each:

Printed Wiring Assembly (PWA)

PWA is the abbreviation for printed wiring assembly. This is an archaic term that was once used to describe what we now refer to as PCB assembly or PCBA. Although it is less common today, understanding this term is useful for historical context and when dealing with older documentation.

Circuit Card Assembly (CCA)

CCA stands for circuit card assembly. It is essentially the same thing as PCBA, where the PCB is assembled with all necessary components to create a functional unit. CCA is a less frequently used term compared to PCBA but is still recognized in certain industries and contexts.

Printed Circuit Board Assembly (PCBA)

PCBA is the abbreviation for printed circuit board assembly. When the PCB is assembled with all its electronic components by SMT technology, it is called PCBA or PCB assembly. Since a change in terminology in 1999, PCBA has become the standard term used for all assembled circuit boards. From users to technical committees, PCBA is the preferred term for referring to assembled boards. The assembly process involves placing and soldering components onto the PCB, making it a functional electronic circuit.

Printed Circuit Assembly (PCA)

PCA stands for printed circuit assembly, which is another term for PCBA. Like CCA, PCA is not commonly used in modern terminology but refers to the same concept of an assembled printed circuit board.

aging test of PWB boards

In a word, whatever for PWB, PCB, or circuit cards, they are refer to bare printed circuit boards (bare boards). While PCA, CCA, PWA, and PCBA refer to assembled circuit boards. Among these terms, PCB and PCBA are the most widely used in both industry and technical documentation.

This is the end of this introduction of PWB and PCB, welcome to contact us if you want more about PCB knowledge.

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What Are the Differences Between Active and Passive Components?
Wednesday, July 3rd, 2024

In PCB electronics, components are classified into two main categories: active and passive components. Understanding these differences is crucial for anyone working with electronic circuits. Active components control electricity flow and require an external power source. Passive components do not control electricity and do not need an external power source.

What are active and passive components meaning?

Active and passive components, simply say, the device that needs an energy (electrical) source is called an active device, and the device that does not need an energy source is a passive device. Active components, such as transistors and diodes, require external power to function. They can control the flow of electricity. Passive components, like resistors and capacitors, do not need external power. They cannot control electrical flow but can store, resist, or filter energy. Both passive and active components are common useful in PCB assembly and SMT technology.

Active components play a dynamic role in circuits. They can amplify signals, switch currents, and perform various complex functions. These components rely on an external power source to operate and influence the behavior of the circuit. For instance, a transistor can amplify a weak signal, making it stronger and more useful for further processing.

What Are the Differences Between Active and Passive Components?

Passive components, on the other hand, are more static in nature. They cannot amplify signals or control current flow but are essential for other functions like energy storage and signal filtering. Resistors, capacitors, inductors, and transformers are common examples. Each of these components has a specific role in maintaining the stability and functionality of an electronic circuit.

What are the key differences between active and passive components?

The main difference between active and passive components is their ability to control electricity. Active components can amplify signals and perform complex tasks. Passive components can only store, resist, or filter energy. They cannot amplify signals or control current.

Active components are energy-dependent. They require an external source of power to function and can influence the flow of electricity within the circuit. For example, an integrated circuit (IC) can perform multiple functions like amplification, switching, and signal modulation, all of which require external power.

Passive components, in contrast, do not require an external power source. They can only perform their functions passively. For instance, a resistor can limit the current flowing through a circuit without needing additional power. Similarly, a capacitor can store electrical energy and release it when needed, all without external energy input.

Common active components in electronics

Active devices are the main components of electronic circuits. From the physical structure, circuit function and engineering parameters, active devices can be divided into discrete devices and integrated circuits.

1. Discrete devices

  • Bipolar transistor, generally referred to as transistor or BJT
  • Field effective transistor
  • Thyristor
  • Semiconductor resistors and capacitors – resistors and capacitors manufactured by integrated technology are used in integrated circuits.

2. Integrated circuit

Integrated circuit can be divided into analog IC and digital IC. Analog integrated circuits mainly deal with continuous analog signals, such as sound, light, temperature, etc., and retain the continuity and accuracy of the signal through amplification, filtering, mixing and other operations. In contrast, digital integrated circuits are used to process discrete time digital signals, convert the signal into binary digital form, and then perform logical operations and processing.

Basic analog integrated circuit devices generally include:

  • Integrated operational amplifier (operation amplifier)
  • Comparator
  • Logarithmic and exponential amplifiers
  • Multiplier/divider
  • Analog switching circuit (analog switch)
  • Phase lock loop
  • Integrated voltage regulator
  • Reference source
  • Wave-form generator
  • Power amplifier

Digital integrated circuit including:

  • Logic gate circuit
  • Flip-flop
  • Register
  • Decoder
  • Data comparator
  • Driver
  • Counter
  • Shaping circuit
  • Programmable Logic Device (PLD)
  • Microprocessor (MPU)
  • Microcontroller (MCU)
  • Digital signal processor (DSP)

Common passive components in electronics

Passive devices in electronic systems can be divided into circuit components and connection components according to the circuit functions they play. These components are essential for functions like energy storage, filtering, and impedance matching in electronic circuits. The common passive components are including:

Circuit components

  1. Diode
  2. Resistor
  3. Resistor network
  4. Capacitor
  5. Inductor
  6. Transformer
  7. Relay
  8. Key
  9. Speaker
  10. Switch

Connection components

  • Connector
  • Socket
  • Cable
  • PCB (printed circuit board)

Why are active components crucial in modern electronics?

The ability of active components to control and manipulate electrical signals makes them indispensable in a wide range of applications.

In computers, for example, active components such as processors and memory chips perform complex calculations and store large amounts of data. In communication systems, active components amplify weak signals, making long-distance transmission possible. Without these amplifiers, the signal would decay with distance, leading to a decline in communication quality. Power electronics, another key area of modern development, relies heavily on active components. Devices like power converters, inverters, and motor controllers use transistors and integrated circuits to efficiently convert and control electrical energy. This efficiency is crucial for applications ranging from renewable energy systems to electric vehicles.

It’s fair to say that without active components, devices like computers, smartphones, and TVS wouldn’t function the way they do today, and our era of big data wouldn’t be moving as fast as it is today.

How do passive components complement active components?

Both active and passive components are indispensable in a circuit. They depend on each other and complement each other. Without active components, the circuit cannot be activated or perform a specific work. Without passive components, the circuit cannot be controlled and adjusted, nor can it achieve a stable operating state. Such a relationship between the two is like the relationship between the “dynamic” and the “static” of a circuit.

What Are the Differences Between Active and Passive Components?

For example, in an audio amplifier circuit, the power supply and amplifier are the active components, and the load and resistance are the passive components. The power supply provides energy, the amplifier amplifies the signal, and controls and limits it through load and resistance, and finally realizes the amplification and regulation of the audio signal. In signal processing, inductors filter out high-frequency noise and protect sensitive active components from interference. Transformers, on the other hand, enable efficient power transfer between different parts of the circuit, allowing active components to operate within their optimal voltage range.

Comparing the Energy Requirements of Active and Passive Elements

Active components need an external power source to function. They consume energy during operation. Passive components do not need external power and generally do not consume energy, except for minor resistive losses. This difference impacts the design and efficiency of electronic circuits.

Active components, such as transistors and integrated circuits, rely on external power to operate. This power requirement means that active components consume energy during their operation. The amount of energy consumed depends on the specific component and its application. For instance, a power amplifier consumes more energy than a simple transistor switch.

Passive components, in contrast, do not need external power to function. They operate solely based on the electrical energy present in the circuit. Resistors, capacitors, and inductors do not consume significant energy, except for minor resistive losses in resistors. This low energy requirement makes passive components more efficient in certain applications.

What Are the Differences Between Active and Passive Components?

The difference in energy requirements between active and passive components impacts the overall efficiency of electronic circuits. Designers must carefully balance the use of active and passive components to achieve optimal performance and energy efficiency. For example, using passive filters instead of active ones can save energy in low-power applications.

Active and Passive Component Images and Symbols

Recognizing symbols are essential for reading and designing circuit diagrams. They provide a visual representation of the components and their functions, helping designers understand the overall structure and operation of the circuit. Recognizing these symbols is a fundamental skill for anyone involved in electronics. Here is a detailed images and symbols listing of common active and passive components.

Above all is the introduction to passive and active components, hope it is useful for every engineers. Best Technology is a professional PCB and PCBA manufacturer in Asia. We have our own factory in China and Vetnam. Welcome to contact us if you have any questions about components and PCB assembly.

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Industrial Motherboard Design, Industrial PCB Case Sharing
Monday, June 24th, 2024

Best technology engaging in the PCB manufacturing and PCB design for more than 17 years. With a strong R&D team, we can provide customers with fast and valued PCB design solutions. Here is one of our industrial motherboard design & industrial PCB case sharing for your reference. If you want to get your own industrial PCB design, welcome to contact us.

A mITX architecture industrial control motherboard

[1] Intel Xeon E3, Core™ i7/i5, Celeron G3900E processors

[2]:2x DDR4 SODIMM 2133 MHz (up to 32 GByte)

[3]:4x SATA Gen 3.0

[4]:1x PCIe x16 (Gen 3)

[5]:2x USB 3.0 (Internal) + 1x USB 3.0 (Client) + 2x USB 3.0 (Rear I/O) + 2x USB 2.0 (Rear I/O) +

2x USB 2.0 (Front Header) + 1x USB 2.0 (mPCIe)

Industrial PCB Design Considerations

  • Control the length of the circuit: Minimize the length of the circuit, especially the key signal lines, to reduce signal attenuation and delay.
  • Avoid sharp angles and right angles: Right angles and sharp angles should be avoided when wiring, and rounded or 45 degree angles should be used as far as possible to reduce signal reflection and impedance discontinuity.
  • Line width: Determine the line width according to the current size and thermal requirements to ensure the reliability and stability of the circuit.
  • Inter-layer wiring: Rational use of multi-layer PCB inter-layer wiring, such as the signal line on the inner layer, power and ground wire on the outer layer.
  • Impedance control: For high-speed signals, it is necessary to control the line impedance to ensure signal integrity, and carry out impedance matching design if necessary.
  • Avoid cross and parallel wiring: Try to avoid cross and parallel wiring of signal lines to reduce crosstalk and electromagnetic interference.

Contact us if you have any questions and inquiry about industrial PCB design projects.

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Why is FR4 Material the Most Commonly Used PCB Material?
Wednesday, June 5th, 2024

FR4 material is a highly popular and widely used substrate in the PCB industry due to its exceptional mechanical strength, electrical insulation, and flame retardant properties. It has become the standard for PCB fabrication.

What is FR4 Material and Why is it Used in PCBs?

FR4 is a type of fiberglass-reinforced epoxy laminate. The term “FR4” comes from its flame-retardant properties, meeting the UL94V-0 standard. It is made from woven fiberglass cloth and epoxy resin, which together provide great strength and durability.

Electrical engineers and designers prefer FR4 because of its many benefits, such as:

  • Low cost
  • High dielectric strength
  • Excellent strength-to-weight ratio
  • Moisture resistance
  • Temperature endurance
  • Good electric loss characteristics
  • Flame retardance and self-extinguishing capabilities
  • Mechanical robustness
  • Insulating properties

FR4 is also suitable for marine PCBs because it absorbs very little water. In a standard FR4 PCB, a layer of FR4 is placed between two thin layers of laminated copper.

FR4 material pcb

What are the Key Performances of FR4 Material?

FR4 material, also recognized as flame retardant 4, is a composite of glass fabric and epoxy resin, predominantly utilized as a foundational material for printed circuit boards. Familiarity with the specifications of FR4 is crucial for selecting the appropriate substrate for PCB manufacturing. Key specifications include:

1. The thickness of FR4 sheet is usually 0.2 mm to 3.2 mm, and other special thickness also available.

2. The specific gravity of FR4 material is about 1.85g/cm3, which means that it is heavier than water.

3. Coefficient of thermal expansion of FR4 is about 1.0×10^-5cm/cm/℃, which means that its length or width will expand slightly when the temperature changes.

4. The thermal decomposition temperature of FR4 materials is usually between 280C and 320C, which makes it able to withstand high temperature applications.

5. FR4 material has a dielectric constant around 4.0-4.8, which makes it an ideal material for circuit board manufacturing.

6. FR4 has good arc resistance, which means that in the case of high voltage, it can effectively prevent arc discharge.

7. FR4 material good hydrolysis resistance and can maintain good performance even in a humid environment.


What are the Types of PCB Materials in the Industry?

PCB materials can be broadly categorized based on their composition and intended application. Nowadays, the commonly used are including FR4, polyimide (PI), Metal material (copper or aluminum), ceramic substrate like Al2O3, AlN, Si3N4, and so on. Different materials have its unique functions and well-suited in specific environment. Here we introduce their properties and suited applications simply.

FR4 (Fiberglass Epoxy Laminate)

At present, almost of PCB you seen in the market or electronics used the FR4 material. It widely used because of its superb equilibrium of mechanical strength, electrical insulation, and cost-efficiency. Actually, according to the different reinforcement materials, the circuit board is mainly classified into the following types:

1) FR-4

2) FR-1, FR-2, etc.

3) CEM series: Composite substrate

FR-4 used frequently because of its high fire resistance rating.

High Tg FR4

Though normal FR4 material has good electrical insulation, it is not an ideal option for high frequency circuit board. And then, high Tg FR4 stands out by using an advanced technology. “Tg” refers to glass transition temperature, the juncture at which the material transitions from a rigid, glassy state to a pliable, rubbery state. High Tg FR4 boasts a Tg of 170°C or higher.

Polyimide (PI)

Polyimide materials are renowned for their excellent flexibility, superior thermal stability and chemical resistance. It is always used as raw material of flex circuits, rigid flex circuit boards or membrane switches. Due to the good chemistry properties, they can endure temperatures up to 260°C and are highly flexible, making them ideal for those small and limited PCB designs.

polyimide pcb

Metal base material

Metal materials always used in metal core PCBs (MCPCB), usually used aluminum core or copper core. The metal base has great thermal conductivity to enhance the thermal management of the device, buy using metal core, the device can dissipate heat away from the critical component such as LED chips, ICs, BGAs, to remain the reliability and performance of the PCB.

metal core pcb

Ceramic substrate

Ceramic PCB substrate offers excellent thermal conductivity and stability than that metal core PCBs, making them suitable for high-power and high-frequency applications. But due to the high cost and complex manufacturing, the ceramic PCB is much expensive than metal core PCB, therefore, they are always be used in high-end applications, such as the military, defense, aerospace and some special fields where requires excellent thermal management.

ceramic pcb

Understanding these materials enable to help engineers and designers in selecting the most appropriate substrate for their projects, ensuring optimal performance and cost-efficiency. Best Technology provides a comprehensive array of PCB materials, guaranteeing high-quality solutions for all your electronic needs.

What are the Applications of FR4 PCB Material in Various Industries?

FR4 material is versatile and finds applications in numerous industries, including:

  • Consumer Electronics like smartphones, laptops, and other personal electronic devices.
  • Applied in vehicle electronics for infotainment systems, engine control units, and more.
  • Industrial Equipment such as control systems, power supplies, and industrial automation.
  • Essential for telecommunications, network devices, routers, and communication infrastructure.
  • Medical instrumentation and diagnostic equipment.
  • Aerospace and defense in avionics, radar systems, and defense electronics.

This is all of this sharing, thanks for your reading. Welcome to contact us if you have other questions about FR4 or other raw materials of PCB. Best Technology engaging in the PCB manufacturing about 18 years, we are one of the leading PCB manufacturers in China. And we have such confidence to provide with you the best PCB and PCBA fast solution for your projects.

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What Is the Role of Electronic Parts on the Circuit Boards?
Tuesday, December 19th, 2023

A circuit board is an independent part of modern electronic devices, equipped with various components that play different roles and functions on the board such as connecting, signal transmission, power distribution, and signal conversion. Theoretically speaking, electronic components are the fundamental units in the devices, and printed circuit board (PCB) serves as a carrier for mounting components, connecting them to completing the functions of electronic systems. Here, we will introduce some common circuit board components and their functions.


What Are Electronic Components?

Electronic components are fundamental building blocks used in the construction of electronic circuits and systems. These components manipulate electrical signals to perform specific functions in electronic devices. Based on their purpose and functionality, electronic components can be categorized into two major types: passive components and active components.

Passive electronic components mainly include resistors, capacitors, inductors, power filters, and so on. They do not have active operational functions such as amplification or signal control. Instead, passive components can only consume or store electrical energy. In electronic systems, their main roles include signal transmission, distribution, filtering, isolation, and other similar functions.

Active electronic components, on the other hand, include transistors, field-effect transistors (FETs), integrated circuits (ICs). Unlike passive components, active components have the ability to actively amplify, control, and manipulate signals related to current, voltage, frequency, and more. They play a crucial role in electronic systems, enabling active operations and functionalities.


What Is the Functionality of Common Components on PCB?

On an assembled circuit board (PCBA), we can see various of components on its surface. Different components play its unique role and have different function. Here we will introduce the function of common components.

  • Resistor

A resistor is a component used to restrict the flow of electric current. Its purpose is to control the magnitude of current by adjusting its resistance value, ensuring appropriate current adjustment within the circuit.

  • Capacitor

The capacitor has the ability to store charge and release it when needed. Its function is to smooth power supply voltage, stabilize current, and in some cases, perform signal filtering to accomplish signal conditioning. Resistors and capacitors are two common types of electronic components.

  • Diode

Diode is a type of component with unidirectional conductivity. The uses of diode enable to allow current to flow in one direction while blocking reverse current. It is commonly used in power supplies, rectifiers, and other circuits.

  • Transistor

A transistor functions in amplification and switching in a printed circuit board. Its role is to amplify electronic signals, control the flow of current, and it is widely used in circuits such as amplifiers and logic gates.

  • Integrated Circuit (IC)

Integrated circuit is a very important components in those small size circuits, because it can integrate multiple functional circuits onto a single chip. That means it can save space if your design has limited space, enhance system performance and reliability of devices. Integrated circuits find widespread applications in areas such as computers, communication systems, and embedded systems.

  • Inductor

The working principle of inductor is similar to a capacitor, but the different is an inductor has the ability to store and release energy while capacitor is to store and release charge. Its main function is to accomplish energy conversion and distribution in a circuit. Inductors are commonly used in circuits for filtering, power supplies, and more.

  • Variable Resistor

A variable resistor allows for the adjustment of resistance and it always used for modifying circuit characteristics by changing the resistance value. Variable resistors are commonly used in circuits for functions like volume control, light intensity adjustment and some other devices that need to adjust the resistance.

  • Light Emitting Diode (LED)

LED chips is a component that we can see everywhere need to light up. It converts electrical energy into light energy. Its function includes emitting light for indicators, illumination, and it is widely used in circuits such as display screens and indicator lights.

  • Power Module

Power module is always designed to provide the electrical energy required by a circuit. Using power to stabilize output voltage and current, protecting the circuit from external power fluctuations.

  •  Sensor

A sensor can perceive physical quantities or signals in the surrounding environment and convert them into electrical signals. Its function is to enable interaction between the circuit and the external environment. Sensors find wide applications in areas such as automatic control, the Internet of Things (IoT), and more.


In summary, the various components on a circuit board have their specific roles, work in conjunction with each other, and collectively achieve the functionality and objectives of the circuit. Understanding the functions of these components allows for a better grasp of the working principles of circuit boards, providing reference and guidance for the design and maintenance of electronic products.

However, for some reasons, inspect the components before PCB assembly is the main method that ensures the reliability of a PCBA. In our next post, we will share how to make the incoming inspection for electronic components, leave your messages if you are interested in it.

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