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What is the density of FR4?

December 24th, 2024

What is the density of FR4?The density of FR4 generally ranges from 1.9g/cm³ to 2.2g/cm³. FR4 is a glass fiber epoxy laminate commonly used in PCB manufacturing. It has high mechanical strength, good heat resistance and excellent electrical properties, so it is widely used in the manufacture of electronic products.

How much does FR4 weigh?

The weight of FR4 varies depending on the thickness and size of the board. It is an epoxy glass fiber cloth laminate, and its weight mainly depends on its volume and density.

What is the density of FR4?

The formula for calculating weight (W) is W = ρ*V, where (V) is volume and (ρ) is density.

Therefore, the weight of FR4 depends on its volume (determined by length, width, and thickness) and density. After knowing the specific size and density, the weight can be accurately calculated.

What is the raw material of FR4?

The raw materials of FR4 mainly include glass fiber and epoxy resin.

FR4 is a composite material made of glass fiber cloth impregnated with epoxy resin and then formed under high temperature and high pressure.

Specifically, FR4 is an epoxy board with a flame retardant grade of 4. Its raw materials include epoxy resin, an organic polymer compound, and glass fiber. This material has excellent insulation, mechanical strength and heat resistance, and is widely used in the electronics industry.

How thick is FR4 PCB material?

The common thickness range of FR4 PCB material is 0.2mm to 3.2mm, of which the most common thickness is 1.6mm.

Specific common thicknesses include 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, 1.6mm, 1.8mm, 2.0mm, etc.

What is the density of FR4?

In addition, the common thickness of FR4 rigid board is 0.8-3.2mm, while the common thickness of thin board is less than 0.78mm.

What are the properties of FR4 material?

The main properties of FR4 material include flame retardancy, mechanical properties, electrical properties, heat resistance, chemical resistance and environmental protection.

  • Flame retardancy: The “FR” in FR4 material stands for “Flame-Retardant”, which means flame retardant. It contains special chemicals that can slow down the spread of fire when a fire occurs and protect electronic equipment from damage.
  • Mechanical properties: FR4 has high strength and stiffness, with tensile strength and compressive strength of up to 65,000 psi and 38,000 psi respectively, which makes it perform well when subjected to mechanical stress.
  • Electrical properties: FR4 maintains good insulation properties in both dry and humid environments. Its dielectric constant is 4.2-4.7, and the dielectric constant changes with temperature, but it does not change much in the temperature range of 0-70 degrees.
  • Heat resistance: The heat resistance of FR4 is represented by the glass transition temperature (Tg), which is usually 130°C, 140°C, 150°C or 170°C. It will not deform or melt when used at 160°C, ensuring the stability and service life of the material.
  • Chemical resistance: FR4 has good chemical resistance and can resist erosion in corrosive environments such as acids and alkalis.
  • Environmental protection: With the increasing awareness of environmental protection, the environmental protection characteristics of FR4 are also valued. Its flame retardant rating reaches 94V-0, and it produces almost no harmful gases when burning, which is more friendly to the environment and human health.

What does the 4 stand for in FR4?

The “4” in FR4 represents its material grade and specific chemical composition.

FR4 is a flame-retardant glass fiber reinforced epoxy laminate, where “FR” stands for “Flame Retardant” and the number “4” indicates the specific grade of this material.

Specifically, FR4 is a double-sided copper-clad PCB board made of epoxy resin and glass fiber cloth, which has excellent mechanical strength, electrical insulation, heat resistance and flame retardancy.

What is the density of FR4?

FR4 has a flame retardant rating of UL94 V-0, which means that it can quickly self-extinguish when burning, greatly improving the safety of electronic products. In addition, FR4 also has excellent mechanical properties, can withstand high temperatures and physical stress, and has good electrical insulation and low moisture absorption, making it suitable for a variety of electronic devices.

What is high Tg FR4 material?

High Tg FR4 material is a special printed circuit board material with a high glass transition temperature (Tg), usually above 170°C. High Tg FR4 material can maintain stable performance and shape in high temperature environments, so it is widely used in electronic devices that need to withstand high temperature and high stress environments.

Advantages and application areas of high Tg FR4 material

  • High temperature resistance: High Tg FR4 material can maintain the stability of shape and performance in high temperature environments, and is suitable for high temperature electronic equipment, automotive electronics, aerospace and communication equipment and other fields.
  • Good electrical properties: Even at high temperatures, high Tg FR4 material can still maintain good electrical properties to ensure the stable operation of the circuit.
  • Stable mechanical properties: High Tg FR4 material has a low coefficient of thermal expansion and can maintain its shape at high temperatures, avoiding curling and deformation.

Why is FR4 used in PCB?

There are several reasons why FR4 material is widely used in PCB:

  • Good insulation: In a circuit, it is crucial to prevent current from flowing in unintended paths. FR4 material is an excellent insulator that can effectively isolate different conductive lines, avoid short circuits, and ensure the normal operation of the circuit.
  • Stable dielectric constant: The dielectric constant of FR4 is relatively stable, which is very critical for the transmission of high-frequency signals. A stable dielectric constant can reduce signal delays and distortion during transmission and ensure signal integrity.
  • Good dimensional stability: FR4 has a low coefficient of thermal expansion, and its dimensional changes are small when the temperature changes, which can keep the PCB size relatively stable and ensure that the connection between electronic components will not loosen or be damaged due to thermal expansion and contraction.
What is the density of FR4?
  • Chemical corrosion resistance: FR4 material has good tolerance to many common chemicals and can resist corrosion from chemicals such as acids, alkalis, and salts, thereby protecting the internal structure and electrical performance of the PCB from damage.
  • Good moisture resistance: Moisture is one of the biggest enemies of electronic equipment, which may cause circuit short circuits, component damage and other problems. FR4 material has a certain moisture resistance, which can prevent the intrusion of moisture and reduce the risk of PCB failure in a humid environment.
  • Easy to process and shape: FR4 material can be easily made into PCBs of various shapes and sizes through a variety of processing techniques. It is suitable for conventional PCB manufacturing processes such as drilling, cutting, and etching, and can ensure high processing accuracy and quality.
  • Relatively low cost: Compared with some high-end special materials, the cost of FR4 material is more reasonable. While meeting the performance requirements of most electronic devices for PCBs, it can effectively control production costs.

In short, the density of FR4 is determined by raw materials and processes. This density has a significant impact on the mechanical properties, electrical properties, and processing technology of the PCB. In production, rigorous measurement and quality control are used to ensure that the density meets the standards. As a professional PCB manufacturer, BEST Technology is well aware of the key role of FR4 density. From material selection to processing, it strictly follows the standards and relies on exquisite craftsmanship to create PCBs with excellent performance for customers to meet diverse electronic needs.

How to read a pcb board?

December 24th, 2024

How to read a pcb board? When reading a PCB board, you need to pay attention to several aspects: First, the substrate, such as FR4, is green or brown, the ceramic substrate is white and brittle, and the aluminum substrate has a metallic texture, and their characteristics are different.

Second, identify the components. Resistors are mostly small cylinders with two pins, marked with resistance values, and play the role of current limiting and voltage dividing; capacitors have various shapes, electrolytic capacitors have polarity for filtering, and ceramic capacitors have no polarity for coupling; integrated circuits are multi-pin black chips, and their functions are known by model; transistors have three pins and can amplify or switch signals.

How to read a pcb board?

Finally, pay attention to solder joints, vias, test points and markings. The solder joints should be good, vias connect multi-layer lines, test points help detection, and markings help track circuits and understand component parameters and areas, so that you can understand the PCB board.

How to read PCB for beginners?

The steps and methods for beginners to read PCB are as follows:

  • Observe the overall structure: First, carefully observe the overall structure of the circuit board, pay attention to the shape, size and color of the circuit board, as well as the markings and labels on it.
  • Identify electronic components: Try to identify various electronic components on the circuit board, such as resistors, capacitors, inductors, diodes, transistors, integrated circuits, etc.
  • Trace the circuit path: Trace the wire path on the circuit board and understand how the circuit is connected. Pay attention to the direction and connection of the wires, and try to trace the circuit path from one component to another and the connections between them.
  • Analyze the circuit board hierarchy: A complex circuit board usually consists of multiple layers. By observing the structure and hierarchy of the circuit board, you can infer the function and design of the circuit board.
  • Read the circuit board markings: There are usually markings, labels, printed text or icons on the circuit board to indicate components, connections or other important information.
  • Reference circuit diagrams and documents: Get the circuit diagram or related documents of the circuit board. The circuit diagram is a graphical representation of the circuit on the circuit board, which can provide more detailed information.
  • Learn basic circuit knowledge: In order to better understand the circuit board, it is recommended to learn some basic circuit knowledge. Understand the basic concepts such as current, voltage, resistance, capacitance in the circuit, as well as common circuit topologies and circuit analysis methods.

How do you analyse a PCB board?

Analysis of PCB boards can be carried out from the following aspects:

  • Check the ink quality: high-quality PCB boards usually use well-known brands of ink, and the printing and baking process is exquisite. Excellent ink has better gloss and thickness.
  • Observe the silk-screen text: the silk-screen text of high-quality PCB boards is clear and three-dimensional, and it is difficult to find the roughness of the edges of the handwriting even under a magnifying glass.
  • Check the smoothness of the V-cut: high-quality PCB boards are more delicate in V-cut processing, and the edges are smooth and free of burrs.
  • Evaluate the color of the board: the color of the board is uniform and there is no obvious color difference, indicating that the production process is stable and the quality is more guaranteed.
  • Check the packaging material: high-quality packaging materials can usually better protect the PCB board and prevent damage during transportation.

How do I identify parts of a PCB?

Identifying the various parts of a PCB (printed circuit board) requires understanding its basic structure and common components.

1. Basic structure

  • Substrate: FR4 (mostly green or brown) is common, as well as ceramic and aluminum substrates. It mainly plays a supporting and insulating role.
  • Copper foil circuit: observe the direction of the circuit, the thicker one carries large current, and the thinner one carries signals; multilayer boards should distinguish between the power layer and the signal layer.
How to read a pcb board?

2. Common components

  • Resistors: small cylinders with two pins, you can see the markings to identify the resistance value. Used for current limiting and voltage division.
  • Capacitors: various shapes, electrolytic capacitors have polarity, and ceramic capacitors have no polarity. Used for storing charge, filtering, etc.
  • Integrated circuits (ICs): black rectangular chips, multiple pins, and model identification, which are the core of realizing complex functions.
  • Transistors: bipolar and field effect types, three pins, used to amplify signals or as switches.

3. Others

  • Solder points and vias: Solder points connect components and circuits, and should be full and smooth; vias are used to connect different layers of circuits.
  • Test points and logos: Test points are used for electrical testing, and logos contain information such as component numbers and values ​​to help understand circuits.

How do you identify PCB material?

To identify PCB (printed circuit board) materials, you can start from the following aspects:

1. Observe the appearance

  • Color: green or brown may be FR4; white and hard and brittle may be a ceramic substrate; silver with a metallic texture may be an aluminum substrate. Color sometimes also implies performance, such as black PCB may have a special design to resist electromagnetic interference.
  • Texture and thickness: touch it with your hand, FR4 is harder and tougher, ceramic is hard and brittle, and aluminum substrate has a metallic texture. The thickness of PCBs for different devices is different, simple devices are thinner, and complex devices are thicker.

2. Reference environment and scenario

  • High temperature environment: Ceramic or metal substrates may be used in high temperature environments, such as automobile engines and industrial furnace control circuits, and aluminum substrates are often used in electric vehicle motor controllers.
  • High humidity environment: High humidity environment requires materials to be moisture-proof. FR4 has a certain moisture-proof ability. Some PCBs that have been specially treated or coated with moisture-proof paint can better resist moisture.
  • High-frequency circuit application: The key to high-frequency circuits is dielectric constant and loss factor. For example, 5G communication equipment and radar systems may use special materials such as polytetrafluoroethylene boards, such as 5G base station antenna boards.

3. Check markings and documents

  • PCB surface markings: Check whether there are manufacturer markings, material types, certification marks, etc. on the surface, such as UL and RoHS certification, to obtain material clues.
  • Product documents and specifications: Find keywords such as “Board Material” in product manuals, technical documents or PCB specifications to determine the material.

How do you find the number of layers in a PCB?

To determine the number of layers of a circuit board (PCB), you can use the following methods to identify it:

  • 1. Check the edge: Observe the edge of the PCB. If you can see multiple layers of copper foil or laminated boards, then this may be a multi-layer PCB. Each copper foil represents a separate PCB layer.
  • 2. Number of holes: Multi-layer PCBs usually have more connection holes. Observe the solder holes on the surface and bottom of the PCB. If there are many holes arranged at intervals, it is likely a multi-layer PCB.
  • 3. Solder mask color: Different layers of a multi-layer PCB are usually distinguished by solder mask of different colors. Check the surface of the PCB to see if there are areas of different colors, which may indicate differences between the layers.
  • 4. Printed markings: PCB manufacturers usually mark the number of layers on the PCB. Check if there are printed markings or labels on the PCB, which may show the number of layers of the PCB.
  • 5. Through the light source: If you have a light source, you can try to illuminate the PCB in a transparent way. Through the PCB, you may be able to see the layout of the internal layers, which can be used to infer the number of layers of the PCB.

What do the numbers on a PCB mean?

The numbers on the PCB board are usually used to identify the category, function number and serial number of electronic components on the circuit board. Specifically, the letter before the number indicates the category of the component, such as R for resistors, C for capacitors, D for diodes, etc.

The number after the number indicates the serial number or function number of the component on the circuit board. For example, R107 means that the serial number of the first resistor is 107, and C118 means that the serial number of the first capacitor is 11812.

How to read a pcb board?

In addition, the number can also represent the functional area or module of the circuit. For example, “1” may represent the motherboard circuit, “2” may represent the power supply circuit, etc., which are determined by the circuit designer.

In some cases, the combination of letters and numbers before the number can also represent specific functions or interfaces, such as SW for switch, LED for light-emitting diode, etc.

What does f stand for on a circuit board?

The “F” on the circuit board usually stands for fuse. In the circuit diagram, the single letter “F” usually represents lightning arrester, while the combination of letters has different meanings, such as “FU” for fuse and “FR” for thermal relay. This is a common representation method in electronic components.

To read the PCB board, you must first identify the substrate material, and then identify various electronic components, such as resistors, capacitors, integrated circuits, transistors, etc., understand their appearance characteristics and functional roles, so as to clarify the circuit connection and signal direction, and thus understand the circuit logic of the PCB board.

Alumina Ceramic PCB: A Comprehensive Guide

December 24th, 2024

Alumina ceramic PCB (Printed Circuit Board) have gained significant attention in industries that demand high performance, such as electronics, medical devices, and automotive systems. Known for their excellent electrical insulation, thermal conductivity, and mechanical strength, alumina ceramics are widely used in applications that require precision and reliability. In this article, we will explore various aspects of alumina ceramics, focusing on their properties, uses, and potential benefits and drawbacks, especially in the context of PCB manufacturing.

What is Alumina Ceramic?

Alumina ceramics are produced by heating aluminum powder in a controlled environment to form a ceramic compound. The material is then used in various applications, such as semiconductors, sensors, and high-performance PCBs.

One of the reasons alumina ceramics is so popular in the electronics industry is its ability to function in harsh environments. It can withstand high temperatures and pressure without degrading, making it perfect for critical applications that require both durability and efficiency.

Can Alumina Ceramic be Machined?

Yes, alumina ceramic can be machined, but it requires specialized tools and techniques. While alumina is a hard material, it is brittle, which means it can crack or shatter if not handled carefully. Precision machining methods like laser cutting, diamond grinding, and CNC milling are commonly used to shape alumina ceramic substrates for PCBs.

Manufacturers can produce alumina ceramic PCBs with fine features, such as microvias or intricate patterns, by using these advanced machining techniques. However, the machining process can be slow and expensive due to the material’s hardness. Despite these challenges, the benefits of alumina ceramics, like their excellent insulation and heat resistance, often outweigh the machining difficulties. At Best Technology, we pride ourselves on delivering multiple types of alumina ceramic PCB products that meet your high-quality standards while maintaining fast delivery times.

What is the Temperature Rating of Alumina Ceramic?

Alumina ceramic has a high-temperature resistance, making it ideal for environments that experience heat stress. Depending on the purity and grade of alumina, its temperature rating can vary, but most alumina ceramics can withstand temperatures ranging from 1600°C to 1900°C. This makes it suitable for applications in power electronics, automotive sensors, and even space exploration.

For PCB applications, the high thermal conductivity of alumina ensures that heat generated by electronic components is efficiently dissipated, preventing damage to sensitive circuits. This property is particularly valuable in power electronics, where overheating can lead to system failures.

Is Alumina Ceramic Magnetic?

No, alumina ceramic is not magnetic. It is a non-metallic material, meaning it does not exhibit magnetic properties. This characteristic makes alumina ceramics ideal for use in electronic components that require isolation from magnetic fields. For instance, in medical devices like MRI machines, non-magnetic ceramics like alumina help avoid interference with the equipment’s functioning.

The absence of magnetic properties in alumina ceramics makes it a preferred material for PCBs used in sensitive electronic applications where magnetic interference could disrupt performance.

Is Alumina Ceramic Safe?

Yes, alumina ceramic is safe to use in a wide range of applications. As a non-toxic and stable material, it poses no significant health risks when handled properly. In fact, it is often used in medical devices, including implants and prosthetics, due to its biocompatibility.

However, like any material, alumina ceramics should be handled with care during manufacturing. Dust or particles generated from machining can be hazardous if inhaled, so it’s important to follow proper safety protocols, such as wearing protective gear and working in well-ventilated areas. Overall, alumina is a safe and reliable material in many high-performance applications.

How Strong is Alumina Ceramic?

Alumina ceramic is known for its impressive mechanical strength. It ranks among the hardest materials available, which is second only to diamond. Alumina’s compressive strength is particularly remarkable, making it highly resistant to wear, abrasion, and pressure. This makes it ideal for applications that require robust components, such as PCB substrates in electronic devices.

The material’s strength also contributes to its durability in extreme environments. For example, in high-frequency communication circuits or power electronic systems, alumina ceramics maintain their structural integrity despite thermal and mechanical stresses.

What is the Advantage of Using Alumina as a Biomaterial?

Alumina has several advantages when used as a biomaterial. Its biocompatibility makes it suitable for medical implants, such as hip replacements and dental implants. The material does not cause allergic reactions or adverse immune responses, which is crucial when used in long-term implants within the human body.

Moreover, alumina’s resistance to wear and corrosion means that it can withstand the mechanical stresses and chemical environments found in the human body. As a result, it has become a popular choice for medical devices and prosthetics. Additionally, alumina ceramics are used in various healthcare technologies like surgical tools and diagnostic devices, benefiting from their precision, durability, and sterilization capabilities.

What are the Disadvantages of Alumina Ceramic?

While alumina ceramics offer many benefits, they do have some disadvantages. One of the main drawbacks is their brittleness. Although alumina is hard, it is also prone to cracking or breaking under sudden stress or impact. This is why it is important to handle alumina ceramics carefully during manufacturing and in application.

Additionally, alumina ceramic processing can be costly. Machining this material requires specialized equipment and skills, which can make it more expensive than other materials, particularly for custom or small-batch productions. Despite these challenges, the benefits of alumina ceramics often outweigh the negatives, particularly in applications that require high performance and reliability.

In brief, alumina ceramic PCBs offer a combination of high thermal conductivity, electrical insulation, and mechanical strength, making them an excellent choice for demanding applications. Whether in high-power electronics, medical devices, or aerospace systems, alumina ceramics provide the reliability and performance needed for modern technologies.

By understanding the properties, uses, and potential drawbacks of alumina ceramic, businesses can make informed decisions about using this material in their products. Despite the machining challenges and brittleness, the advantages of alumina—such as its heat resistance, safety, and mechanical strength—make it a preferred choice in various industries.

Choosing the right material for PCB manufacturing can be complex, but alumina ceramic continues to be a top contender for those seeking durable, high-performance substrates. If you are looking for reliable PCB solutions, alumina ceramic offers the performance you need to ensure your devices operate efficiently and effectively. As a qualified alumina ceramic pcb manufacturer, Best Technology is striving to provide multiple types of PCB products without MOQ requirement for our customers. Just feel free to reach out to us via sales@bestpcbs.com to get the personalized service.

What is copper oxydation pcb?

December 23rd, 2024

What is copper oxydation pcb?Copper oxidation is the process of copper reacting chemically with oxygen in the air to form copper oxide. When PCB is exposed to humid air, moisture will be adsorbed on the copper surface. In the early stage of this oxidation process, only a very fine and imperceptible discoloration layer may be formed on the copper surface, but with the passage of time and the continuous action of oxidation conditions, the oxide layer will gradually thicken.

What is PCB Oxidation?

PCB oxidation refers to the phenomenon that the metal wire or pad surface on the PCB board reacts chemically with oxygen to form an oxide layer. This oxide layer is usually formed by oxides on copper materials, mainly including copper oxide (CuO) or cuprous oxide (Cu2O).

What is copper oxydation pcb?

The reasons for PCB oxidation are varied, mainly including the following points:

  • Environmental factors: high temperature and humidity, high pH or pollutant-containing environments will accelerate the oxidation process of PCB boards.
  • Manufacturing and storage conditions: During the manufacturing and storage process, if the appropriate temperature and humidity are not maintained, or if the packaging is improper, causing the PCB to be exposed to moisture and corrosive gases, oxidation is likely to occur.
  • Chemical reaction: The metal part on the PCB reacts with moisture and chemicals in the surrounding environment, which is also an important cause of oxidation.

What are the effects of PCB oxidation?

PCB oxidation will have many effects on the performance and reliability of electronic products. First, oxidation will lead to a decrease in conductivity, making the circuit board prone to poor contact, cross-connection and short circuit problems, thereby affecting the use effect and performance of electronic products.

Second, oxidation may cause short circuits and fires, because the oxide layer will form a conductive rust layer, which may cause safety accidents once a short circuit occurs. In addition, oxidation will also reduce the stability and reliability of the circuit board, because the oxide layer reduces the protective layer on the surface of the circuit board, making it more susceptible to interference and fluctuations during long-term operation.

To prevent PCB oxidation, the following measures can be taken:

  • Control humidity and temperature: Store the PCB in a dry and ventilated environment, avoiding humidity and high temperature environments.
  • Use high-quality materials: Choose a circuit board with a copper-plated protective layer, which can effectively reduce the degree of oxidation.
  • Moisture-proof treatment: Use a moisture-proof treatment agent to treat the PCB with moisture to enhance its stability.
  • Daily maintenance: Regularly inspect and maintain the PCB to detect and deal with surface corrosion in a timely manner.

What are the types of PCB corrosion?

The types of PCB corrosion mainly include the following:

  • Atmospheric corrosion: This is the most common type of corrosion, usually caused by a chemical reaction between oxygen and moisture in the air and copper, resulting in the formation of copper oxide on the copper surface, reducing the conductivity of the circuit board, but the mechanical properties remain unchanged.
What is copper oxydation pcb?
  • Local corrosion: This type of corrosion mainly affects a limited or small area, usually due to exposure to an environment with excessive humidity. Local corrosion includes filiform corrosion, crevice corrosion, and pitting corrosion.
  • Galvanic corrosion: occurs when two different metals (such as copper and another metal) are coupled in a corrosive electrolyte. Galvanic corrosion causes one metal to corrode faster than the other, usually when one end of the wire/cable is connected to the positive electrode and the other end is connected to the negative electrode.
  • Electrolytic corrosion: occurs when an ionized substance (electrolyte) comes into contact with two electrodes and current passes through the PCB. The electrolyte speeds up the rate of electrochemical reactions, causing the corrosion process to accelerate.
  • Fretting corrosion: Electrochemical corrosion occurs when two metal surfaces come into contact with each other and one of the metals is in a corrosive environment. Fretting corrosion usually occurs between two different metals, such as copper and steel or copper and aluminum, causing current to flow from copper to steel or aluminum, forming copper oxide.
  • Electrolytic dendrite formation: When there is ion contamination in the moisture, dendrites are formed on the copper traces, causing short circuits between traces. This deformation causes metal strips to grow from adjacent copper traces with different voltages, ultimately leading to a short circuit.

How to remove oxidation from PCB?

The methods for removing oxides from PCBs mainly include physical removal, chemical reduction, surface treatment, and environmental control.

1. Physical removal method:

  • Fine sandpaper wiping: For mild oxidation, fine sandpaper (non-iron sandpaper) can be used to gently wipe the oxide layer until the metallic luster is restored.
  • Diluted acid soaking: For more serious oxidation, you can soak the circuit board in diluted sulfuric acid, hydrochloric acid or white vinegar (acetic acid). After the oxide layer is corroded, clean it with alcohol.

2. Chemical reduction method:

  • Dimethyl borane alkaline solution: Use alkaline solution mainly composed of dimethyl borane to reduce the oxidized surface of the inner layer copper foil to enhance acid resistance and adhesion.
  • Sodium thiosulfate reduction solution: Use sodium thiosulfate reduction solution with a pH value of 3-3.5 to treat copper surface whiskers to form a coating layer of copper and cuprous oxide mixture to improve antioxidant capacity.

3. Surface treatment method:

  • Tin plating: Tin plating on the surface of the PCB to form a protective layer, which effectively prevents oxidation and has a low cost.
  • Gold plating: Gold plating can provide higher corrosion resistance, but the cost is higher.
  • Coating anti-oxidation coating: Use anti-oxidation coating to form a strong, corrosion-resistant protective layer to isolate the PCB surface from contact with air.

4. Environmental control method:

  • Control the ambient temperature and humidity: During the manufacturing, storage and transportation of PCBs, strictly control the temperature and humidity of the environment to avoid exposing the PCB to high temperature, high humidity or pollutant-containing environments.
  • Choose appropriate packaging materials: such as moisture-proof bags, foam boxes, etc. to ensure the integrity and quality of the PCB.

How to protect PCB from oxidation?

The methods to protect PCBs from oxidation include the following aspects:

  • Choose high-quality substrates: Select substrates with strong antioxidant properties, such as FR-4, high TG boards or aluminum substrates.
  • Control the ambient humidity: During the manufacturing and storage process, maintain a low humidity environment to reduce the risk of oxidation, because high humidity will accelerate the occurrence of oxidation reactions.
What is copper oxydation pcb?
  • Use antioxidants: During the manufacturing or assembly of PCBs, antioxidants are applied to protect the circuit layer from oxidation, which can be implemented during the packaging and coating process.
  • Surface treatment process: The use of metal plating with strong antioxidant properties, such as gold plating, silver plating, tin plating, etc., can form a protective film on the surface of the metal circuit to prevent the occurrence of oxidation reactions.
  • Regular cleaning and maintenance: Use appropriate cleaning agents and regular cleaning methods to remove possible dirt and oxides and keep the PCB surface clean.
  • Reasonable storage and use environment: Avoid exposure to humid, high temperature, and highly polluted environments. It is best to use sealed packaging and place it in a dry and cool place. During use, pay attention to keeping the electronic equipment clean and prevent dust, moisture and other pollutants from entering the PCB.

What chemical is used to clean PCB?

Common chemicals for cleaning PCBs include water-based cleaning agents, hydrocarbon cleaning agents, and organic solvents.

Water-based cleaning agents use water as the cleaning medium and improve the cleaning effect by adding a small amount of surfactants, detergent aids, and corrosion inhibitors. This cleaning agent has a good dissolving effect on water-soluble dirt and is suitable for batch cleaning.

Hydrocarbon cleaning agents are suitable for manual scrubbing and local surface treatment wiping, but the air in the working environment must be unobstructed. Hydrocarbon cleaning agents have weak cleaning power and are flammable and explosive safety risks.

The organic solvent cleaning process is relatively simple, and only the same solvent needs to be used for cleaning and rinsing. Common organic solvents include trichloroethylene, carbon tetrachloride, etc. These solvents have a good dissolving effect on dirt, but attention should be paid to their volatility and safety.

Copper oxidation PCB involves many links in electronic manufacturing, from design to manufacturing, from use to maintenance, and negligence at each stage may lead to this problem, thereby damaging the performance of the PCB. As a professional PCB manufacturer, BEST Technology blocks oxidation factors from cleaning to packaging. Once an oxidation problem occurs, special cleaning agents are used for minor treatments, and professional processes such as micro-etching and electroplating are used for repair.

Let you know about refrigerator pcb

December 23rd, 2024

What is a refrigerator pcb? Refrigerator PCB is usually composed of insulating substrate, copper foil circuit and various electronic components. Insulating substrate provides support for circuits and components. Common materials include epoxy glass fiber board, which has good insulation performance, mechanical strength and stability, and can adapt to the complex environment inside the refrigerator.

Do refrigerators have PCBs?

There are PCBs inside refrigerators. The PCB of a refrigerator is one of the core control components of the refrigerator, usually called the computer version or control board of the refrigerator. It is responsible for controlling various functions of the refrigerator, such as refrigeration, preservation, energy saving, etc. It monitors and adjusts the operating status of the refrigerator in real time through sensors and control systems to ensure that the refrigerator can work efficiently and stably.

Let you know about refrigerator pcb

What is a PCB in a fridge?

The PCB in a refrigerator is an important part of the refrigerator control system. The role of PCB in a refrigerator mainly includes the following aspects:

  • Connection and control: As the core of the refrigerator control system, PCB controls the switch and operation of the refrigerator by connecting various sensors and other electrical components. It integrates various sensors, such as temperature sensors and humidity sensors, to provide real-time feedback on the temperature and humidity conditions in the refrigerator, thereby achieving automatic control.
  • Interactive function: PCB can interact with users through alarm lights, buzzers and displays to control various functions of the refrigerator, such as constant temperature, refrigeration and thawing.
  • Intelligent function: For high-end refrigerators, PCB can also achieve more functions and information feedback by connecting to the Internet. For example, users can remotely control the refrigerator through mobile phone APP, set the laundry program in advance or let the sweeping robot start working, etc.
  • Maintenance: In order to ensure the normal operation of PCB, it is necessary to clean and inspect it regularly, and ensure that its installation location is dry and ventilated to avoid moisture. In addition, avoid changing the temperature and appliance settings at will to avoid affecting automatic control.

What role do PCBs play in refrigerators?

The role of PCB in refrigerators mainly includes controlling various functions of refrigerators, processing sensor signals, realizing the interconnection of home appliances and improving the intelligence level of refrigerators.

1. Control various functions of refrigerators

PCB is one of the core control components of refrigerators, responsible for controlling various functions of refrigerators, such as refrigeration, preservation, energy saving, etc. Through sensors and control systems, PCB can monitor and adjust the operating status of refrigerators in real time to ensure that refrigerators can work efficiently and stably.

Let you know about refrigerator pcb

2. Processing sensor signals

PCB smart home appliance board is responsible for processing signals from various sensors, such as temperature sensors and humidity sensors in refrigerators. Through accurate analysis and processing of these signals, smart home appliance board can automatically adjust the operating status of home appliances according to preset programs.

3. Realize the interconnection of home appliances

PCB smart home appliance board also realizes the interconnection of home appliances. With the help of network module, smart home appliances can be connected to the home wireless network, and users can remotely control home appliances through mobile phone APP.

Can refrigerator PCB be repaired?

Refrigerator PCB (Printed Circuit Board) can be repaired. If the PCB of the refrigerator fails, you can take the following steps to repair it:

  • Check the warranty period: First check whether the refrigerator is within the warranty period. If it is within the warranty period, you can contact after-sales for free repair or replacement.
  • Self-inspection and simple repair: For some simple problems, you can check and repair them yourself. If the refrigerator does not run after power on, you can check whether the fuse, plug, temperature controller contacts, etc. are normal.
  • Replace PCB: If the PCB is severely damaged, you may need to replace the entire PCB. You can buy an identical PCB to replace it yourself, but you need to be careful when disassembling it, especially not to damage other components.

What is the common damage of a refrigerator?

Common causes of refrigerator PCB damage mainly include the following:

  • Overvoltage: The working voltage of the refrigerator circuit board is 220V. If the voltage is too high, the circuit board will be overloaded and damaged. It is recommended to use a socket with stable voltage or a voltage stabilizer to protect the circuit board.
  • Overload: Hanging items on the refrigerator or placing heavy objects on its door will cause the door to be poorly sealed, air circulation to be blocked, and the refrigerator to work abnormally, which will lead to circuit board overload.
Let you know about refrigerator pcb
  • Sudden power outage: Sudden power outage or lightning may cause damage to the refrigerator circuit board. In case of power outage or bad weather, it is recommended to disconnect the power supply or use a protective device.
  • Poor heat dissipation: The temperature of the refrigerator compressor continues to rise, and it cannot dissipate heat in time, which will burn out the fuse and other components, causing damage to the refrigerator circuit board.
  • Unstable voltage: Unstable voltage cannot meet the power used by the refrigerator, which will cause damage to the refrigerator circuit board. It is recommended to install a voltage stabilizer to protect the circuit board.

How much does it cost to replace a circuit board in a refrigerator?

The cost of replacing a circuit board in a refrigerator is affected by many factors:

  • Refrigerator brand and model: The design, function and complexity of the circuit board of refrigerators of different brands and models vary greatly, and the price will also vary greatly. The circuit boards of high-end brands or refrigerators with complex functions are usually more advanced, more sophisticated and more expensive.
  • Fault severity: If only individual components on the circuit board are damaged, the problem can be solved by repairing and replacing the components, and the cost is relatively low; but if the circuit board has serious problems such as short circuits and burns, the entire circuit board needs to be replaced, and the cost will increase significantly.

How much does it cost to repair a PCB?

The cost of repairing a PCB is affected by many factors, as follows:

1. Fault type

  • Component damage: If only individual ordinary components are damaged, such as capacitors and resistors, the repair is relatively simple and the cost is low; if key components such as chips are damaged, the repair is difficult and the cost will increase significantly.
  • Circuit problem: The difficulty of repairing a circuit break or short circuit varies depending on the complexity of the circuit. The cost of repairing a simple circuit is low, and the cost of repairing a circuit problem on a multi-layer board or high-density circuit board is high.
  • Solder joint problem: It is relatively easy to repair the cold soldering and desoldering of a small number of solder joints, and the cost is not high; but if a large number of solder joints have problems or the solder joints are located in important parts such as chips, the repair cost will increase.
  • Software failure: For the PCB boards of some smart devices, if there are software failures, professional software engineers are required to debug and repair them, which may increase the repair cost.

2. Circuit board type

  • Computer motherboard: The repair of ordinary desktop computer motherboards is relatively common and easy, and the cost is average; while the notebook motherboard has high integration and complex structure, which is difficult to repair and the cost is usually high.
  • Mobile phone motherboard: Mobile phone motherboards are small in size and highly integrated. Repair requires high-precision equipment and technology, and mobile phones are updated quickly. The repair costs of motherboards of different models vary greatly.
  • Home appliance circuit boards: The circuit boards of common home appliances such as TVs, refrigerators, washing machines, etc. have relatively simple functions, and the repair costs are generally stable, but if they are circuit boards of high-end smart home appliances, the repair costs may be higher.
  • Industrial control circuit boards: Industrial control circuit boards have extremely high requirements for stability and reliability, and usually use high-quality components and complex designs. They are difficult to repair and costly.

How to customize refrigerator PCB?

Customizing refrigerator PCB requires the following steps:

  • Clear requirements: determine the functional requirements of the refrigerator, consider the use environment of the refrigerator, determine the PCB’s operating temperature range, humidity requirements, electromagnetic compatibility and other performance indicators.
  • Design circuit: According to the requirements, use professional design software to draw circuit diagrams, layout and wiring; plan the board layers reasonably. For refrigerator PCBs with complex functions, multi-layer board design can be used; consider the heat dissipation problem. For heating components, they should be laid out as close to the edge as possible, and heat sinks or heat dissipation holes can be added to ensure the temperature stability of the PCB during operation.
  • Select materials: According to the use environment and performance requirements of the refrigerator, select the appropriate substrate and the appropriate copper foil thickness to meet different current carrying capacity and signal transmission requirements. According to the electrical performance and environmental adaptability requirements, select the surface treatment process, etc.
Let you know about refrigerator pcb
  • Manufacturing and testing: During the manufacturing process, drilling holes needs to be accurately drilled, electroplating ensures the formation of a good conductive layer, etching removes excess copper foil, silk-screens clear and accurate symbols and component identification, and uses automated optical inspection equipment to quickly and accurately inspect the PCB. Electrical and functional tests are also performed to ensure that the PCB meets the design requirements and performance standards.
  • Assembly and debugging: Assemble electronic components onto the PCB through surface mount technology or through-hole technology, pay attention to welding quality, perform system debugging on the assembled PCB, check whether the various functions of the refrigerator are normally implemented, such as temperature control accuracy, start and stop and operation status of the refrigeration system, intelligent interconnection function, etc., and make timely adjustments and optimizations to any problems that arise.

As a key component of the refrigerator, the refrigerator PCB should be designed to take into account the special environment of the refrigerator, and be resistant to low temperature, humidity, and electromagnetic interference. BEST Technology will start from the design of the refrigerator PCB and customize the best solution based on the characteristics and needs of different refrigerators. In the production process, various process standards are strictly followed, and then the finished product is strictly tested to ensure the high quality of the PCB layer by layer.

Understanding Aluminum Backed PCBs: Benefits and Uses

December 23rd, 2024

Learn everything about aluminum backed PCBs, including their advantages, limitations, and how they handle heat.

Aluminum-backed PCBs, also known as aluminum PCBs or aluminum core PCBs. These PCBs offer a unique combination of excellent thermal conductivity and structural strength, making them ideal for applications like LED lighting, power electronics, and automotive circuits.

What Is Aluminum Backed PCB?

An aluminum-backed PCB is a type of printed circuit board (PCB) where the base layer is made of aluminum rather than the traditional fiberglass or other materials. The key difference is the metal core, which significantly enhances the thermal conductivity of the PCB. The aluminum core is typically covered with a dielectric layer that isolates the conductive circuit from the metal base, allowing the PCB to maintain its electrical properties while providing better heat dissipation.

The combination of the aluminum base and the dielectric layer makes these PCBs ideal for high-power applications where heat management is essential. The aluminum core helps quickly dissipate heat away from sensitive components, thus improving the overall efficiency and lifespan of the device.

Understanding Aluminum Backed PCBs: Benefits and Uses


What Temperature Can Aluminum PCB Withstand?

Aluminum PCBs are designed to withstand high temperatures, but the exact temperature tolerance depends on several factors, including the thickness of the aluminum substrate and the quality of the dielectric layer. In general, aluminum-backed PCBs can handle temperatures up to about 130°C. However, it’s important to note that the temperature tolerance also depends on the specific materials used in the construction of the PCB and the environmental conditions in which it operates.

For high-power applications like LEDs, where heat is generated during operation, aluminum PCBs are a great choice because they help maintain lower temperatures. By dissipating heat effectively, they prevent components from overheating, which could otherwise damage the circuits.

How Thick Is the Dielectric Layer of Aluminum PCB?

The dielectric layer of an aluminum PCB plays a crucial role in providing electrical insulation while also allowing heat to be transferred away from sensitive components. The thickness of the dielectric layer typically ranges from 50µm to 200µm, depending on the application and the desired thermal performance.

Thicker dielectric layers are used in high-power applications where enhanced electrical insulation and thermal management are required.

What Are the Advantages of Aluminum PCB?

Aluminum PCBs offer several advantages, which make them an attractive choice for many industries. Here are some of the most notable benefits:

1. Superior Heat Dissipation: One of the key advantages of aluminum-backed PCBs is their excellent thermal conductivity. The metal base helps quickly dissipate heat away from the components, reducing the risk of overheating and prolonging the lifespan of the device. This makes them ideal for applications like LED lighting, power supplies, and high-power electronic devices.

2. Lightweight and Durable: Despite being made from metal, aluminum PCBs are lightweight yet durable. The metal core provides structural integrity without adding unnecessary weight, which is especially important in industries like automotive and aerospace.

3. Enhanced Performance: The combination of a high-quality dielectric layer and the aluminum substrate leads to better electrical performance, especially in high-current applications. Aluminum PCBs provide a stable platform for components to function optimally, minimizing electrical noise and interference.

4. Cost-Effective: Compared to other types of dissipation heat materials, aluminum-backed PCBs can be more cost-effective, especially for applications where heat dissipation is critical. Their lower manufacturing costs combined with higher production efficiency can reduce overall production costs, making them a preferred option for many applications.

5. Widely Applications: Aluminum-backed PCBs are primarily used in applications where heat dissipation is a concern. They are excellent for high-power applications, audio device, Communication electronics, Office automation equipment, automobile, computer, and etc. As a chief manufacturer partner for aluminum PCB, Best Technology provides custom service and full turn-key solutions. For more information or any inquiry, warm welcome to reach out to us via sales@bestpcbs.com.

Understanding Aluminum Backed PCBs: Benefits and Uses

What Are the Disadvantages of Aluminum PCB?

While aluminum-backed PCBs offer numerous benefits, there are some drawbacks to consider. However, these limitations are generally outweighed by their advantages in many applications. Let’s look at a few of the challenges:

1. More Complex Manufacturing Process: The manufacturing process for aluminum-backed PCBs can be more complex compared to traditional PCBs. This complexity can increase the production time and cost, especially for custom designs.

2. Mechanical Stress: Aluminum is a relatively soft metal, which means it can be prone to deformation or bending under mechanical stress. This makes it unsuitable for applications where the PCB will be subject to harsh physical conditions or mechanical pressure.

3. Conductive Issues: The surface of aluminum PCB is prone to oxidation. Besides, The heat conductivity coefficient of aluminum is relatively low. Thus the metal core of aluminum PCBs can sometimes create challenges in terms of electrical grounding. Proper design and careful manufacturing are essential to ensure that the electrical properties of the PCB are maintained.

Understanding Aluminum Backed PCBs: Benefits and Uses

Why Is Aluminum No Longer Used in Integrated Circuits?

While aluminum used to be a common material for integrated circuits (ICs), it has largely been replaced by copper and other materials in modern IC manufacturing. There are several reasons for this shift:

1. Better Electrical Conductivity of Copper: Copper has better electrical conductivity than aluminum, making it the material of choice for interconnects in integrated circuits. Copper’s lower resistance allows for faster signal transmission and better overall performance.

2. Miniaturization of ICs: As ICs have become smaller and more complex, aluminum’s larger size and weaker electrical properties no longer meet the demands of modern integrated circuit design. Copper allows for the miniaturization of ICs without sacrificing performance.

3. Corrosion Resistance: Aluminum is more prone to oxidation compared to copper, which can affect the long-term reliability of integrated circuits. Copper, on the other hand, is more resistant to corrosion and offers better durability.

Despite these factors, aluminum still plays a crucial role in specific applications, particularly in PCBs where heat dissipation is the primary concern. Its ability to manage heat effectively makes it a valuable material in the realm of power electronics and LED technology. At Best Technology, quality is the priority. With 18 years manufacturing experience, we can provide high-quality Aluminum Backed PCBs solutions with fast delivery. Pls feel free to contact us to get more information and personalized solutions.

In a nutshell, aluminum-backed PCBs offer an effective solution for managing heat in high-power applications, making them a popular choice in industries like LED lighting, automotive electronics, and power supply systems. With advantages like superior thermal conductivity and lightweight durability, aluminum PCBs are a top choice for projects that require efficient heat dissipation.

However, they do come with some challenges, including more complex manufacturing processes and potential mechanical stress. Understanding these limitations is key to determining whether an aluminum PCB is the right choice for your specific needs. Whether you’re designing a custom aluminum PCB for LED lighting or exploring its benefits for power electronics, these PCBs offer unique advantages that make them a valuable asset in modern electronic design.

What is a flip chip cob led?

December 20th, 2024

What is a full flip chip cob led? COB (Chip On Board), or chip on board packaging technology, is a technology that directly packages multiple LED chips on a circuit board. Unlike traditional LED packaging methods, COB LEDs do not need to package each chip separately, but instead arrange them closely and integrate them on a common substrate to form a light-emitting module.

What is a COB flip chip?

COB flip chip refers to a packaging technology, the full name of which is Chip on Board (chip directly on the board), where “flip” refers to the packaging method of the chip. Flip chip COB technology packages LED chips directly on the PCB substrate, covers the silicon wafer with thermally conductive epoxy resin, and performs heat treatment, and finally establishes an electrical connection between the chip and the substrate through wire bonding.

What is a flip chip cob led?

Its characteristics and applications:

  • Simple structure: Full Flipped chip COB technology has a simpler structure, reduces gold or copper wire connections, and simplifies the manufacturing process.
  • High temperature resistance: This packaging method has better high temperature resistance and improves the stability and reliability of the product.
  • Good heat dissipation performance: Due to the reduction of connecting parts, the heat dissipation performance is improved, reducing the risk of dead lights and falling lights.
  • Widely used: Flip-chip COB technology is widely used in indoor small-pitch LED displays.

Comparison with other packaging technologies

  • Formal COB: The formal chip packaging method is earlier, the process is mature but the stability is poor, it is easily affected by moisture, and it affects the light output efficiency and heat dissipation efficiency.
  • Mixed COB: Mixing formal and flip chips, taking into account cost and performance, is suitable for the transition stage.

What is a flip chip used for?

The main functions of flip chips include:

  • Reduce signal delay and parasitic inductance: Flip chips are directly electrically connected to the pads of the package substrate through bumps, without the need for long bonding wires, so the signal path is shorter, which can effectively reduce signal delay and parasitic inductance.
  • Improve heat dissipation performance: Since the chip is directly connected to the substrate through bumps, heat is more easily transferred to the substrate, thereby improving heat dissipation performance.
  • High I/O pin density: Flip chips have higher I/O pin density, save area, and are suitable for high-performance and high-integration applications.
  • Improve package reliability: Flip chips use metal ball connections, which are compact and reliable, so they are increasingly used in the packaging industry.
  • Reduce package size: Using metal ball connections can reduce package size, improve electrical performance, and solve the problem that traditional packaging methods need to expand volume due to increased pin counts.

How does a flip-chip work?

The working principle of flip chip technology is to form bumps on the active side of the chip, and then align and weld the active side of the chip with the pads on the substrate facing down, thereby achieving direct electrical connection between the chip and the substrate.

What is a flip chip cob led?

This connection method not only reduces the package volume, but also improves signal transmission speed and reliability because the signal path is shorter and the parasitic inductance and capacitance effects caused by wire bonding are avoided.

What are the disadvantages of flip chip?

The main disadvantages of flip chips include thermal stress problems and reliability problems. Due to the mismatch in the coefficient of thermal expansion (CTE) between the chip and the substrate, when the temperature changes, the solder joints will be subjected to large thermal stress, resulting in fatigue damage and failure. In order to solve these problems, the bottom filling process is usually adopted, that is, polymer materials are injected into the gap between the chip and the substrate to improve the stress distribution of the solder joint, reduce the strain amplitude, and extend the thermal fatigue life of the solder joint.

In addition, flip chip technology faces some challenges in practical applications, including:

  • Material selection and process optimization: As chips become increasingly miniaturized and thinner, the requirements for the performance of filling materials and packaging reliability continue to increase. Material design, process optimization and other measures are effective ways to deal with potential challenges.
  • Wide-scale use of lead-free solder: The use of lead-free solder has put forward new requirements for the bottom filling process, which requires further research and improvement.

What are the different types of flip chips?

There are mainly the following types of flip chips:

FCBGA (flip chip ball grid array package):

  • Process characteristics: FCBGA uses small balls instead of pins for welding, has high I/O density, can effectively solve electromagnetic compatibility and electromagnetic interference problems, and reduce the packaging area. In addition, its good heat dissipation performance enables the chip to work stably at higher power.
What is a flip chip cob led?
  • Application areas: Widely used in high-end microprocessor and graphics processing chip packaging, such as high-end CPU and GPU, to ensure the stability and performance of the chip when running at high frequency.

FCCSP (Flip Chip Size Package):

  • Process characteristics: FCCSP can achieve chip size and package size close to each other, suitable for portable electronic devices with strict space requirements. Its compact packaging form minimizes the space occupied by the package while ensuring chip performance.
  • Application areas: Suitable for devices with limited internal space such as smartphones and tablets, which can reduce the package space while ensuring performance, leaving more space for other components.

Cob flip chip vs smd

SMD and COB each have their own advantages and disadvantages. Which technology to choose depends on the specific application scenario and requirements.

Application scenarios and comparison of advantages and disadvantages

1. Packaging method:

  • SMD: SMD (Surface Mount Device) technology is to package LED chips into lamp beads and then solder them on the PCB board. This technology is mature and low-cost, and is suitable for LED displays with regular spacing.
  • COB: COB (Chip-on-Board) technology is to directly package the LED chip on the PCB board, with a smaller dot pitch, which is suitable for micro-pitch LED display screens. Although the cost is higher, the process is simpler and the dot pitch can be smaller.

2. Dot pitch:

  • SMD: The dot pitch is larger, usually reaching P20 to P1.25, but it is difficult to reduce further.
  • COB: The dot pitch is smaller, suitable for products of P1.25 and below, such as P0.93, P0.78, etc.

3. Cost:

  • SMD: Due to mature technology and low cost, it is suitable for large-scale production and conventional applications.
  • COB: Due to the high cost of technology and materials, it is suitable for the high-end, high-demand micro-pitch LED display market.

4. Stability and life:

  • SMD: Due to the protrusion of the lamp beads, it is easy to cause the problem of falling or dead lights during installation and removal.
  • COB: Directly encapsulated on the PCB board, the probability of falling and dead lights is reduced, and the stability is better.

5. Optical performance and heat dissipation performance:

  • SMD: The light spot may be uneven due to the independent light emission of multiple LED chips, and the color rendering performance is affected by the design and materials. Heat dissipation performance is affected by the packaging design of a single LED chip.
  • COB: Multiple LED chips are closely arranged, the light spot is uniform, the color rendering performance is good, and the heat dissipation area is large and uniform.

What is the difference between flip chip and BGA?

The main difference between flip chip (Flip Chip) and BGA (Ball Grid Array) lies in the packaging method and application scenario.

1. Packaging method

  • Flip chip (Flip Chip): Flip chip is a packaging technology that directly solders the contact points of the chip to the substrate. The contact points of the chip (usually metal balls) are directly connected to the contacts on the substrate to form an electrical connection.
  • BGA (Ball Grid Array): BGA is a surface mounting technology in which the chip is connected to the pads on the substrate through its contact points (usually ball pins). BGA packaging usually uses a solder ball array, and the solder balls are fixed to the substrate by reflow soldering.

2. Application scenarios and advantages and disadvantages

Flip chip:

  • Advantages: Reduced resistance and parasitic capacitance, increased signal transmission speed; small package size, suitable for high-density integration; high reliability because of reduced connection points.
  • Disadvantages: Complex manufacturing process and high cost; requires precise alignment and welding technology.
  • Application scenarios: Suitable for high-performance computing and high-speed signal transmission occasions, such as CPU, GPU, etc.

BGA:

  • Advantages: Increased I/O pin count and increased packaging density; increased assembly yield; improved electrothermal performance.
  • Disadvantages: Occupies a large substrate area; relatively complex manufacturing process and high cost.
  • Application scenarios: Suitable for high pin count and high performance requirements, such as high-end processors, graphics processing units, etc.

What is the difference between flip chip and COB?

Flip chip and COB (Chip on Board) have significant differences in definition and application.

1. Definition and basic concepts

  • Flip chip is a chip packaging technology in which the I/O end (pin) of the chip faces downward and is connected to the substrate through solder bumps. This technology can improve packaging density and electrical performance, and is often used in high-performance computing and communication equipment.
  • COB (Chip on Board) is a technology that directly packages chips on circuit boards, aiming to solve the shortcomings of traditional LED displays, such as dead lights and falling lights, and improve stability and resolution. COB technology is divided into two types: positive and flip.
What is a flip chip cob led?

2. Packaging method:

  • Flip chip: The I/O end of the chip faces down and is connected to the substrate through solder bumps.
  • COB: The chip is directly packaged on the PCB board, which is divided into positive and flip. The positive chip faces up and is connected through welding wires; the flip chip faces down and is directly connected to the PCB without welding wires.

3. Application field:

  • Flip chip: Widely used in high-performance computing, communication equipment and other fields, it is favored for its high-density installation and good electrical performance.
  • COB: Mainly used in LED displays, especially in the field of high-end displays. COB technology can solve the problems of high thermal resistance, high cost and smaller spacing in traditional SMD packaging.

4. Advantages and Disadvantages:

  • Flip chip: Advantages include high packaging density and good electrical performance; Disadvantages are complex production process and high cost.
  • COB: Formal COB has lower cost, but there are wire bonding problems that affect stability and heat dissipation efficiency; Flip chip COB has high process requirements, better stability, strong thermal conductivity, but higher cost.

Flip chip COB LED integrates the advantages of COB packaging and flip chip technology, achieving precise light color control and uniform light distribution in optical performance, excellent electrical performance, efficient heat dissipation, and strong stability. As a professional PCB manufacturer, BEST Technology is committed to creating high-quality PCBs for flip chip COB LEDs and providing stable and reliable solutions.

How to use a pcb prototype board?

December 20th, 2024

How to use a pcb prototype board? To use a PCB prototype board, you need to prepare components and tools according to the design, check the board, lay out the components reasonably and solder them. After soldering, first visually inspect, then power on and test each module with an oscilloscope, etc. If there is a problem, check the connection, change components, and adjust parameters to debug. Clean and store it after use.

What is a PCB prototype?

PCB prototypes are early samples of products, mainly used to test design concepts and verify the feasibility of designs. It not only tests basic user functions, but also needs to have certain functionality to ensure that the overall function of the design can operate normally. During the PCB prototype production process, engineers can test different PCB designs and manufacturing specifications to find the best solution.

How to use a pcb prototype board?

The role of PCB prototypes:

  • Shorten time: Through PCB prototypes, design engineers can quickly and accurately test design problems and reduce the number of design iterations, thereby shortening the design cycle and reducing costs.
  • Improve customer satisfaction: Customers can see product prototypes in advance, which can better communicate needs, reduce misunderstandings and rework during design and production, and ensure that the final product meets customer needs.
  • Ensure design feasibility: PCB prototypes can test circuit boards before production, discover and fix potential design defects, and avoid rework and cost waste after production.

How to make PCB prototyping?

The following are brief steps to make PCB prototypes:

  • Step 1: Design circuit schematics

Use the schematic capture tool to select components according to circuit functional requirements and connect them logically in the software. After drawing, check its logic and integrity, and use the electrical rule check function to troubleshoot errors to ensure that it meets the requirements.

  • Step 2: Plan PCB layout

Import components into the layout software, place them reasonably according to component characteristics, plan wiring at the same time, take into account power lines, ground lines and high-speed signal wiring requirements, and adjust components and wiring to meet rules and space restrictions.

  • Step 3: Generate production files

Generate Gerber files, make BOM materials list at the same time, and communicate with manufacturers to ensure that the files meet production requirements.

  • Step 4: Select the manufacturing method

Choose breadboard (flexible but high contact resistance, etc.), perforated board (needs soldering, more stable but more complicated wiring) or PCB manufacturing (high quality but high cost, long cycle) according to the complexity, size and budget of the circuit.

  • Step 5: Manufacture PCB board

Breadboard directly plugs components and connects jumpers; perforated board needs to solder components; PCB manufacturing gives relevant documents to manufacturers for production according to the process, and maintains communication during the process to ensure quality and delivery.

  • Step 6: Drilling
How to use a pcb prototype board?

Choose a drill bit according to the size of the component pin, use a drilling machine to drill vertically, control the depth, especially for multi-layer boards, and clean up the debris in the hole after drilling.

  • Step 7: Soldering components

After cleaning the component pins, place them in the corresponding position of the PCB, use a soldering iron, solder wire (hot air gun for patch, etc.) to solder according to specifications, and check the quality of the solder joints after soldering to ensure that there are no problems such as false soldering and short circuits.

  • Step 8: Test the circuit board

Perform visual inspection (look at the appearance, component installation, solder joints, etc.), functional testing (input signals according to the designed functions to see if the output meets expectations) and electrical testing (use instruments to measure whether the electrical parameters are normal) to promptly troubleshoot and repair problems.

How much does a PCB prototype cost?

The cost of a PCB prototype varies depending on many factors, mainly including circuit board size, number of layers, materials, process complexity, etc.

  • Circuit board size: The larger the circuit board, the higher the cost.
  • Number of layers: Multi-layer circuit boards are usually more expensive than single-layer or double-layer circuit boards because the manufacturing process is more complicated.
  • Material type: Different materials have different costs, and high-performance materials are usually more expensive.
  • Surface treatment: Surface treatment processes such as gold plating and immersion gold will affect the cost.
  • Minimum line width, line spacing, aperture: The higher the accuracy requirements of these parameters, the higher the cost.
  • Special requirements: Additional requirements such as impedance control and special markings will increase the cost.

What is the difference between prototype PCB and assembly?

The main difference between prototype PCB and assembly lies in their purpose, quantity, production cycle and cost.

1. Purpose and quantity

  • Prototype PCB: Mainly used to test and verify the design, ensure the feasibility and performance of the design in practical applications, and its quantity is usually large.
  • Assembly: Usually refers to mass production, the quantity is usually more than 500 pieces, or even thousands of pieces.

2. Production cycle and cost

  • Prototype PCB: The production cycle is short, usually no more than 10 days, suitable for rapid testing and adjustment of the design. Although the unit price is high, the total cost is low because problems can be discovered and solved in time to avoid losses during mass production.
  • Assembly: The production cycle is long, generally 20-25 days. The unit price is low, but the total cost is high because a large number of products need to be produced.

3. Design and production process

  • Flexibility: The prototype PCB production process is more flexible and can be adjusted and modified according to design requirements.
  • Quality control: The quality control standards of prototype PCB can be moderately relaxed to complete production faster. Mass production requires strict quality control to ensure that each board is defect-free.

Is a breadboard a protoboard?

A breadboard is a prototype board, also known as a solderless breadboard or a universal circuit board. It is mainly used for prototyping and experimental verification of electronic circuits. It can quickly assemble and test circuits without soldering.

How to use a pcb prototype board?

The structure of a breadboard includes a conductive hard substrate, an insulating material layer, and an epoxy glass cloth board or a double-sided glass cloth board covered with a copper layer. There are many holes on the top for plugging electronic components, such as DIP (dual in-line package), SMD (surface mount device) and THT (through-hole technology).

The breadboard uses U-shaped metal contacts to hold component leads and wire segments inserted through holes, and uses spring tension to fix components, providing a flexible and convenient way to connect circuits.

The use scenarios of breadboards are very wide, suitable for prototyping and debugging of various electronic projects. Due to its characteristics of not requiring soldering, breadboards are particularly suitable for beginners and experimenters who need to frequently replace components.

What is the difference between PCB prototype and breadboard?

PCB prototype and breadboard have the following main differences in prototyping:

1. Usage:

  • Breadboard: When using breadboard for circuit construction, you only need to insert the component pins into the corresponding small holes, without soldering, which is very suitable for temporary circuit testing and small-scale prototyping.
  • PCB prototype: You need to use circuit design software to draw a circuit diagram first, and then convert the design into conductive lines and component layout on the PCB. The PCB is made through a series of processes, and finally the components are soldered to the PCB to complete the circuit construction.

2. Advantages and disadvantages:

Breadboard:

  • Advantages: easy to use, flexible, can quickly build and modify circuits; no professional tools and equipment are required, suitable for beginners and small-scale production.
  • Disadvantages: The circuit connection is not stable enough and is easily affected by vibration and temperature difference; it is not suitable for large-scale production and complex circuit design; after long-term use, the metal contact points are easily oxidized and cause poor contact.

PCB prototype:

  • Advantages: The circuit connection is stable and reliable, suitable for the design and production of various complex circuits; it can achieve high-density wiring and compact arrangement of components; it is easy to realize automated production and batch replication; it has good protection performance and can resist interference from the external environment.
  • Disadvantages: The design and production costs are relatively high, requiring professional knowledge and skills support; the production cycle is long, not suitable for rapid prototyping and temporary testing needs; once the production is completed, the circuit structure and component layout are not easy to modify.

3. Applicable scenarios:

  • Breadboard: suitable for beginners and small-scale prototyping, as well as temporary circuit testing.
  • PCB prototype: suitable for the design and production of complex circuits, as well as the needs of large-scale production and long-term stable operation.

What are the three types of breadboards?

Breadboards are mainly of the following three types: solderless breadboard, single breadboard and combination breadboard.

  • Solderless breadboard: This breadboard has no soldered power socket, is small in size, easy to carry, and is suitable for small circuit experiments. Its disadvantage is that the power connection is inconvenient and not suitable for large-scale circuit experiments.
How to use a pcb prototype board?
  • Single breadboard: Single breadboard is small in size, easy to carry, and can be easily turned on and off. But its disadvantage is that it is small in area and not suitable for large-scale circuit experiments.
  • Combination breadboard: Combination breadboard is to fix multiple solderless breadboards on the motherboard, and connect the power lines of each board together through the copper foil in the motherboard.

The use of PCB prototype board covers several key steps such as preparation, inspection, layout welding, testing and debugging, and maintenance and preservation. As a professional PCB manufacturer, BEST Technology has rich practical experience in the design and development of PCB prototypes. From the precise drawing of the schematic to the high-quality prototype production, every link is strictly controlled to ensure the provision of excellent performance, stable and reliable PCB prototypes.

Is rf assembly high frequency or low frequency?

December 19th, 2024

Is rf assembly high frequency or low frequency?RF components have a wide operating frequency range, covering multiple frequency bands from low frequency to high frequency. Generally speaking, the RF band generally refers to 3kHz to 300GHz, but in actual applications, 3kHz to 30MHz is often regarded as a low-frequency RF range, such as some simple wireless remote controls, while 30MHz to 300GHz belongs to high-frequency RF.

What is high-frequency vs low frequency?

Definition of high frequency and low frequency

  • Low-frequency circuit: mainly used to process signals with lower frequencies, usually in the range of tens of hertz to several thousand hertz. Common applications include audio circuits, etc.
Is rf assembly high frequency or low frequency?
  • High-frequency circuit: used to process signals with higher frequencies, usually in the range of several thousand hertz to several hundred megahertz. High-frequency circuits are very important in applications such as communications, radars, and satellites.

Differences between high frequency and low frequency in PCB design

  • Power supply design: In high-frequency PCB design, the power supply design is usually one layer, which can minimize signal loops and thus reduce noise.
  • Signal integrity: High-frequency PCB design requires special attention to signal integrity, including signal transmission delay, reflection and crosstalk.

Is RF high or low-frequency?

RF (radio frequency) is high frequency. It refers to the electromagnetic frequency that can be radiated into space. Its frequency range is from 300kHz to 30GHz, so it belongs to the high-frequency category. Alternating current that changes less than 1000 times per second is called low-frequency current, while alternating current that changes more than 10,000 times per second is called high-frequency current. RF is such a high-frequency current.

Basic characteristics of RF

  • Frequency and wavelength: The frequency of RF is between 300kHz and 30GHz. The wavelength is inversely proportional to the frequency, that is, the shorter the wavelength, the higher the frequency. The frequency of RF is higher, so the wavelength is shorter.
  • Amplitude and phase: The amplitude signal of RF represents the measure of the change of electric field oscillation, and the phase represents the position of a single time point in the wave cycle.
  • Modulation: In order to achieve communication, the RF signal needs to be modulated. Modulation includes analog modulation and digital modulation, which uses frequency, phase and amplitude to transmit data.

What is the highest RF frequency?

The highest frequency of RF (radio frequency) is 300GHz. Within this frequency range, RF is widely used in fields such as radar and wireless communication.

The basic characteristics of RF include frequency, wavelength, amplitude and phase. Frequency refers to the frequency of electromagnetic field oscillation, measured in Hertz (Hz). Wavelength is inversely proportional to frequency, that is, wavelength is equal to the speed of light divided by frequency. The amplitude of RF refers to the measure of the change in electric field oscillation, while the phase indicates the position of a single time point in the wave cycle.

How do you know if the frequency is high or low?

In PCB design, judging whether the frequency is high or low is mainly based on the frequency range of the signal.

Definition of frequency range

  • High frequency: usually refers to signals with frequencies between 3MHz and 300GHz. In PCB design, signals greater than 50MHz are generally considered high-speed signals, and signals with rising/falling edges less than 50ps are also considered high-speed signals.
Is rf assembly high frequency or low frequency?
  • Low frequency: usually refers to signals with frequencies between hundreds of Hz and hundreds of kHz.

Specific applications in PCB design

  • High-frequency PCB design: In high-frequency PCB design, the power supply design is usually one layer, which can minimize the signal loop and thus reduce noise. In addition, high-frequency signals are susceptible to interference, so special attention should be paid to noise issues in the design.
  • Low-frequency PCB design: Low-frequency circuit design usually does not need to consider signal loops and noise issues too much, but it is still necessary to pay attention to signal integrity and electromagnetic compatibility.

Measurement methods and tools

  • Oscilloscope: Oscilloscope is a common tool for measuring signal frequency. The frequency range of the signal can be judged by observing the waveform.
  • Spectrum analyzer: Spectrum analyzer can measure the frequency component of the signal more accurately and is suitable for occasions requiring high-precision measurement.

What is high-frequency PCB?

High-frequency PCB is a special type of circuit board designed specifically for processing high-frequency signals, and its operating frequency can reach hundreds of megahertz (MHz) to tens of gigahertz (GHz). High-frequency PCB occupies a key position in high-frequency application scenarios such as wireless communication, 5G, Wi-Fi, radar, and high-speed data transmission.

Is rf assembly high frequency or low frequency?

High-frequency PCB has a low dielectric constant, which leads to less signal loss during transmission. It is suitable for efficient transmission. It uses special materials to ensure a small dielectric constant, thereby ensuring transmission speed and meeting the needs of high-speed data transmission. In the field of precision metal material heating treatment, high-frequency PCB can achieve heating of components of different depths to meet various heating needs.

What is RF PCB?

RF PCB is a printed circuit board specially used for RF circuit design and manufacturing. It has unique characteristics and requirements in high-frequency signal transmission, impedance control, shielding and isolation, miniaturization and high-density wiring.

It is mainly used to process high-frequency signals, usually above 100MHz, and is widely used in wireless communications, radar systems and other application scenarios that need to receive and send wireless signals.

What is microwave PCB?

Microwave PCB (microwave printed circuit board) is a circuit board specially designed to process microwave frequency band signals. Microwave PCB usually works in microwave bands with a frequency greater than 2GHz. It uses a specific microwave substrate copper clad board and is produced through a special manufacturing process to meet the low-loss and low-delay transmission requirements of high-frequency signals. Its characteristics include:

Is rf assembly high frequency or low frequency?
  • Low loss: Microwave PCB uses materials with low dielectric constants to reduce energy loss during signal transmission.
  • High stability: stable performance in high temperature and high humidity environments, ensuring reliable signal transmission.
  • Low latency: suitable for high-speed data transmission needs, ensuring signal accuracy and stability.

The frequency range of RF components covers low frequency and high frequency, with unique characteristics and a wide range of application scenarios. As the key foundation for supporting the operation of high-frequency RF components, the characteristics and design of high-frequency PCB directly affect the performance of RF components. From signal integrity to system stability to miniaturization integration capabilities, they are inseparable from the careful design and optimization of high-frequency PCB.

What is NPTH in PCB?

December 18th, 2024

What is NPTH in PCB? NPTH is a through hole on PCB, but unlike plated through hole, its hole wall is not treated with electroplated metal. These holes are usually used for mechanical installation, positioning or as non-electrical connection purposes such as ventilation and heat dissipation channels.

What is an NPTH?

NPTH refers to non-plated through hole, that is, a hole without electroplated metal on the hole wall. The hole wall of NPTH hole is not electroplated with metal and is usually used for positioning, fixing or as a screw hole. These holes do not participate in electrical connection and are mainly used for mechanical fixing or structural support.

What is NPTH in PCB?

NPTH holes are often used in the following scenarios:

  • Positioning hole: used to position and fix other components or parts on PCB.
  • Screw hole: used to install screws and fix PCB or other components.
  • Mounting hole: used to install connectors or other external devices.

What is the full form of NPTH?

The full name of NPTH is “Non Plating Through Hole”. In printed circuit boards (PCBs), NPTH refers to holes whose walls are not plated with metal and therefore do not participate in electrical connections. Such holes are usually used for positioning, fixing screws or other non-conductive purposes.

What is the difference between PTH and non PTH?

The main difference between PTH (Plating Through Hole) and NPTH (Non Plating Through Hole) is whether the hole wall is plated.

1. Plating:

  • PTH: The hole wall is plated and is usually used for electrical connections, such as vias (VIA) and component holes. There is copper on these hole walls, which can achieve electrical conduction between the layers of the circuit board.
  • NPTH: The hole wall is not plated and is usually used for positioning, fixing and other functions, such as screw holes or connector fixing holes. There is no copper in these hole walls and does not participate in electrical connections.

2. Appearance characteristics:

  • PTH: There are traces of plating, the hole wall is smooth and covered with copper.
  • NPTH: There are no traces of plating, the hole wall is not smooth and not covered with copper.

3. Application scenarios:

  • PTH: Mainly used in scenarios where electrical connection is required, such as connecting different layers of a circuit board or connecting components.
  • NPTH: Mainly used in scenarios where electrical connection is not required, NPTH holes usually do not have hole rings, but in some special cases, hole rings are also designed to achieve grounding functions.

What is a PTH pad?

PTH pads (Plated Through Hole) refer to pads with through holes, and the hole walls are copper-plated. PTH pads play an important role in PCB design, and are mainly used to connect different layers of a circuit board or connect component pins to a circuit board.

The following points should be noted during the design and manufacturing process of PTH pads:

  • Size and shape: The outer ring of the PTH pad cannot be less than 0.2mm (8mil) on one side to ensure stability during welding.
  • Welding process: During welding, the PTH pad will take away a considerable amount of solder, which may cause insufficient solder problems.
  • Manufacturing capability: The design of the PTH pad is directly related to the manufacturing capability of the circuit board, which may cause welding quality problems.

PTH pads play a key role in PCB assembly, ensuring stable connection of components and reliable electrical performance. Correct PTH pad design can significantly improve the reliability and manufacturing quality of the circuit board.

How thick is plated through-hole plating?

The plating thickness standards for plated through-holes vary depending on the application scenario. Specifically:

  • IPC Level 1: The smallest thickness, short service life, usually used in consumer electronics that may become obsolete in a few years, requires an average thickness of 20 microns, and spots are not thinner than 18 microns.
  • IPC Level 2: More durable, continuously used holes, suitable for equipment that often runs for 5 years or more, requires an average thickness of 20 microns, and spots are not thinner than 18 microns.
  • IPC Level 3: The thickest and most durable plated through-holes, used for products expected to be used for ten years or more, requires an average thickness of 25 microns, and spots are not thinner than 20 microns.

What is the anatomy of a plated through-hole?

A plated through-hole (PTH) is a hole drilled in a circuit board, and a layer of metal is deposited on the hole wall through an electroplating process to achieve electrical connections between different layers of the circuit board. Its construction usually includes the following parts:

  • Hole wall: The hole wall of the plated through-hole is formed by drilling, usually in a circular or other shape.
  • Metal plating: A layer of metal deposited on the hole wall by electroplating process to achieve electrical connection. The thickness and quality of the metal plating have an important impact on the electrical performance and reliability of the plated through-hole.
  • Pad: Located at both ends of the plated through-hole, it is used to solder electronic components or connect other circuit boards. The shape and size of the pad are usually designed according to the type and size of the electronic component.
  • Solder mask: A layer of insulating material covering the surface of the circuit board to prevent solder flow and short circuit during soldering. The solder mask usually leaves a certain opening around the plated through-hole to solder electronic components.

What is the required hole fill of a plated through-hole?

The required hole fill of a plated through-hole is usually required to reach 100%. Specifically, the plated through-hole (PTH) should be filled with 100% vertical solder, the solder side should have a perfect fillet, and the component and pad should be in 100% contact with the solder.

The surface of the weld should be smooth, non-porous, non-disturbed, bright, and the solder joints completely wrap the solder feet and are concave. In addition, electroplating hole filling technology also plays an important role in improving the electrical performance and connection reliability of circuit boards.

What is NPTH in PCB?

Electroplating hole filling can improve electrical performance, improve connection reliability, avoid electromagnetic interference, and has excellent solderability and a more simplified process. In practical applications, electroplating hole filling is suitable for blind holes with a diameter of 80-220um and a thickness-diameter ratio of less than or equal to 1:1. The hole filling rate can reach more than 85%.

What is the difference between plated and coated?

The main difference between plating and coating lies in their formation method and application scenarios.

1. Formation method

  • Plating: Plating is a metal protective layer formed on the surface of the material by electroplating or chemical plating. Electroplating is to use the principle of electrolysis to plate a thin layer of other metals or alloys on certain metal surfaces to form a metal film. Chemical plating is to form a metal coating on the surface of the material through chemical reaction.
  • Coating: Coating is a protective layer formed by spraying paint on the surface of the material. Common coating methods include hot-dip galvanizing, thermal spraying and surfacing, which mainly apply metal to the surface of the substrate by physical means.

2. Application scenarios

  • Plating: Plating is widely used in aviation, automobile, electronics and other fields. In the aviation field, coating can improve the mechanical strength and processing accuracy of parts and reduce the weight of parts; in the automotive field, coating can improve the corrosion resistance and wear resistance of the car body.
  • Coating: Coating is widely used in construction, machinery, automobile and other fields. In the construction field, coating mainly plays the role of anti-corrosion, waterproof, heat preservation, etc.; in the mechanical field, coating can enhance the hardness, wear resistance and corrosion resistance of the material surface.

3. Advantages and disadvantages

  • Plating: Advantages include good anti-corrosion, anti-wear, electrical conductivity, thermal conductivity and aesthetics. Disadvantages are complex process and high cost.
  • Coating: Advantages are simple process, low cost, anti-corrosion, waterproof, wear resistance, heat insulation and other characteristics. Disadvantages are that the aesthetics and some physical properties are not as good as plating.

Although NPTH in PCB does not directly participate in electrical connection like plated through holes, it plays an irreplaceable role in mechanical installation, heat dissipation, etc., and together with plated through holes, it constitutes a complete functional system of PCB.