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What is the profit margin for recycling waste circuit boards Circuit boards are common components in many electronic products, and are also present in commonly used household appliances. Nowadays, electronic products update and iterate very quickly, and the elimination rate is also high. Once electronic products are eliminated, they will become waste. According to statistics, the total amount of electronic waste generated annually in China is over 8.2 million tons, which is a very large quantity. And its metal content is dozens of times that of ordinary mineral metals, making it a good raw material for collecting and extracting metals. Some even turn waste circuit boards into "urban mines". Some people may not be particularly familiar with circuit boards, which contain up to 40% metal, with copper accounting for a higher proportion, as well as gold, aluminum, nickel, lead, silicon, and other metals. Often, circuit boards are broken, crushed, and sorted using circuit board recycling
Is PCB a printed circuit board PCB board, also known as printed circuit board or printed circuit board in Chinese, is a support body for electronic components and a provider of electrical connections. PCB board is an indispensable component in electronic devices. It is produced through electronic printing technology, using an insulating substrate covered with conductive patterns and solder pads for assembling and soldering electronic components. The main function of PCB board is to fix and connect various electronic components, realizing the preset functions of the circuit. According to different structures, PCB boards can be divided into single panel, double-sided board, and multi-layer board. A single panel only has conductive patterns on one side, while a double panel has conductive patterns on both sides and is connected through vias. A multi-layer board has three or more layers of conductive patterns, which are laminated and interconnected to form a complex circuit network.
SMT (Surface Mount Technology), also known as Surface Mount Technology, is a modern electronic manufacturing technology. SMT surface mount technology is mainly used to mount electronic components onto printed circuit boards (PCBs). Compared with traditional plug-in technology, SMT surface mount has many advantages. Firstly, SMT patches can achieve miniaturization and high-density assembly of electronic components. Due to the fact that electronic components can be directly mounted on the surface of PCBs without the need for plug-in holes, the size and weight of PCBs can be greatly reduced, thereby improving the integration of electronic devices. Secondly, SMT surface mount technology has the characteristics of high efficiency and high degree of automation. SMT surface mount machines can quickly and accurately mount electronic components onto PCBs, greatly improving production efficiency. Meanwhile, SMT surface mount technology can achieve fully automated production, reducing manua
Materials required for PCB production process The materials required in the PCB production process mainly include copper foil, photoresist film, etching agent, solder film, components, etc. Among them, copper foil is the basic material of PCB board, photoresist film is used to make the graphics and circuits of PCB board, etchant is used to etch away excess copper foil, solder film is used to protect the circuits and pads of PCB board, and components are important components on PCB board. Equipment required for PCB production process The equipment required in the PCB production process mainly includes plate making machines, etching machines, drilling machines, coating machines, welding equipment, testing equipment, cleaning equipment, etc. Among them, the plate making machine is used to make photoresist film, the etching machine is used to etch off excess copper foil, the drilling machine is used to drill holes, the coating machine is used to cover the solder film, the soldering eq
What are the ways to split PCB circuit boards PCB board splitting refers to the process of cutting large boards into multiple independent small boards to meet the needs of different sizes and shapes. Board splitting is an important step in the PCB manufacturing process, aimed at producing independent circuit boards that meet design requirements. There are various ways to split PCB boards, and the following will introduce several common ways of splitting: 1. Milling and cutting of PCB boards: Using a CNC milling machine, cut grooves on the PCB board and use a rotating tool or milling cutter to cut the board into small pieces, suitable for various shapes and sizes of boards. 2. Punching and Splitting: Through die-cutting technology, holes are pressed on the PCB board, and then force is applied to break the board, achieving the splitting operation, suitable for rectangular and regular shaped boards. 3. V-knife board splitting: Use a special V-shaped blade to cut V-shaped slots on t
Precautions for PCB production process Accuracy of design documents The success or failure of PCB production is related to the accuracy of the design documents, so it is necessary to design PCB boards as accurately as possible and conduct multiple verifications and modifications. Accuracy and quality of plate making Plate making is the core process of PCB production, and its accuracy and quality directly affect the quality and stability of the PCB board. Therefore, the plate making process requires precise operation and control to ensure the accuracy and quality of the plate making. Etching control Etching is one of the key processes in PCB production, and it is necessary to control the parameters such as etching time, temperature, and concentration to avoid incomplete or excessive etching. Quality of welding Welding is one of the important processes in PCB production, and it is necessary to control the temperature, time, pressure and other parameters of welding to ensure the
1. The outer frame (clamping edge) of the PCB panel should adopt a closed-loop design to ensure that the PCB panel will not deform after being fixed on the fixture; 2. PCB panel width ≤ 260mm (SIEMENS line) or ≤ 300mm (FUJI line); If automatic dispensing is required, the PCB panel width x length should be ≤ 125mm x 180mm; 3. The shape of the PCB panel should be as close to a square as possible, and it is recommended to use 2 × 2, 3 × 3,... panels; But don't assemble it into a yin-yang board; 4. The center distance between the small boards should be controlled between 75mm and 145mm; 5. When setting the benchmark positioning point, a solder mask area 1.5 mm larger than the positioning point is usually left around it; 6. There should be no large or protruding components near the connection points between the outer frame and the inner small board, and between the small boards themselves. Additionally, there should be a space of more than 0.5mm between the components and the edges
What is the function of PCB board ventilation holes The ventilation holes on the PCB board mainly have the following important functions: 1、 Balanced air pressure During the process of temperature changes on the PCB board, such as reflow soldering, wave soldering, or temperature changes in actual usage environments, the air inside the PCB board will undergo thermal expansion and contraction. If the PCB board is completely sealed, this change in air pressure may cause deformation, delamination, or other physical damage to the PCB board. The presence of breathable holes can maintain a balance between the air pressure inside the PCB board and the external air pressure, avoiding damage to the PCB board caused by stress due to pressure differences. 2、 Eliminate moisture and volatile substances During the manufacturing process of PCB boards, such as cleaning and coating, there may be residual moisture or volatile substances inside the PCB board. If these moisture and volatile substanc
Drilling holes for circuit boards Drilling holes in circuit boards is a crucial step in the manufacturing process of printed circuit boards (PCBs). Its main purpose is to drill holes of various diameters on the circuit board to achieve electrical connections between different layers and the installation and fixation of components. PCB drilling is usually done using specialized CNC drilling machines. These drilling machines have the characteristics of high precision and high speed, which can meet the strict requirements of modern electronic devices for PCB manufacturing. During the drilling process, the drill bit rotates at high speed and moves downwards to form a hole by cutting the material of the circuit board. In order to ensure the quality and accuracy of drilling, it is necessary to control parameters such as drill speed, feed rate, and drilling depth. The quality of PCB drilling directly affects the performance and reliability of the PCB. If there are deviations, rough hole
PCB heat dissipation design In modern electronic devices, as the integration level of integrated circuits increases and the operating frequency continues to rise, power consumption also increases accordingly, and heat dissipation issues become increasingly prominent. Good PCB heat dissipation design is crucial for ensuring the stability, reliability, and prolonging the service life of electronic devices. PCB heat dissipation design mainly starts from the following aspects: Firstly, it is necessary to arrange the components reasonably. Arrange components with high heat generation at the edges of the PCB or near ventilation openings as much as possible to facilitate heat dissipation. At the same time, avoid placing multiple high heat components together to prevent the formation of local hotspots. When laying out electronic components, the path of air flow should also be considered to ensure that the air can flow smoothly through the heating components and take away the heat as much
Process flow of single-sided and double-sided multi-layer circuit board 1. The process flow of single-sided circuit board cutting and edge grinding → drilling → outer layer graphics → (full board gold plating) → etching → inspection → silk screen solder mask → (hot air leveling) → silk screen characters → shape processing → testing → inspection. 2. The process flow of double-sided circuit board tin spraying is as follows: cutting and grinding the edges → drilling → copper sinking and thickening → outer layer graphics → tin plating, etching and tin removal → secondary drilling → inspection → silk screen solder mask → gold-plated plug → hot air leveling → silk screen characters → shape processing → testing → inspection. 3. The process flow of double-sided circuit board nickel plating and gold plating includes cutting and grinding edges, drilling holes, copper sinking and thickening, outer layer graphics, nickel plating and gold film etching, secondary drilling, inspection, silk scre
Copper coating conditions for PCB circuit boards (1) For boards that require strict impedance control, do not apply copper as it can affect impedance control due to the distributed capacitance between the copper and the wiring; (2) For devices and PCBs with high wiring density in the upper and lower layers, copper plating is not necessary. At this time, the copper plating is fragmented and basically ineffective, and it is difficult to ensure good grounding; (3) For single-sided and double-sided power boards, it is important to ensure that the power cord is connected to the ground wire and not to use copper plating. If copper plating is used, it will be difficult to ensure a proper circuit; (4) If it is a PCB with more than 4 layers (excluding 4 layers), and the second layer and the second to last layer are complete ground planes, copper plating is not necessary. However, if the device and wiring density of the upper and lower layers are small, copper plating is better; (5) If th
What to pay attention to when cooperating with circuit board manufacturers 1、 Pay attention to doing a good job in sampling work The production of any product cannot be separated from the crucial sampling process, especially in equipment manufacturing such as circuit board production, which requires high technical investment. Any order for circuit board production of any size should be accompanied by the manufacturer to complete the preliminary sampling work. Then, the actual presentation effect of the sample product and the testing of various key indicators must be done well and confirmed, which is a guarantee for both the demander and the circuit board manufacturer themselves. 2、 Pay attention to the review of design drawings Before the circuit board production is put into formal production, we should provide all information related to the design of the batch of circuit boards. The circuit board manufacturer and their professional personnel should review the design drawings aga
BGA packaging has developed to be fully compatible with current soldering and assembly technologies. CSP or close pitch BGA have gate spacing of 0.5, 0.65, and 0.80mm, while plastic or ceramic BGA has relatively wider contact spacing (1.50, 1.27, and 1.0mm). BGA with coarse and dense spacing are less susceptible to damage than pin packaging ICs with dense spacing. The BGA standard allows for selective removal of contact points to meet specific I/O requirements. When establishing the contact point layout and pin distribution for BGA, the packaging developer must consider the chip design as well as the size and shape of the circuit chip (die). Another issue encountered when planning pin distribution is the orientation of the circuit chip. When suppliers use chip on board technology, they usually adopt a form where the circuit chip faces up. PCB sampling PCB board sampling PCB board sampling The structure of circuit board prototype components is not specified in industry standards an
Circuit board sampling is divided into rigid circuit boards, flexible circuit boards, and soft hard composite boards. A general PCB is called a rigid PCB, and the intuitive difference between a rigid PCB and a flexible PCB is that a flexible PCB can be bent. The common thicknesses of rigid PCBs include 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.6mm, 2.0mm, etc. The common thickness of flexible PCB is 0.2mm, and a thick layer is added behind the part to be soldered. The thickness of the thick layer varies from 0.2mm to 0.4mm. The purpose of understanding these is to provide structural engineers with a spatial reference when designing. Common materials for rigid PCBs include phenolic paper laminates, epoxy paper laminates, polyester glass felt laminates, and epoxy glass cloth laminates; Common materials for flexible PCB prototyping include polyester film, polyimide film, and fluorinated ethylene propylene film. According to the number of circuit layers, it can be classified into si
What are the requirements for PCB multi-layer circuit board sampling? Nowadays, various enterprises pay special attention to product quality. In the manufacturing industry, the improvement of product quality also plays an important role in the industry's reputation. PCB multi-layer circuit boards have good quality in the circuit board manufacturing industry. Therefore, many PCB multi-layer circuit board manufacturers will conduct multi-layer board sampling before production to verify whether the circuit design performance meets the requirements. The following is an analysis of the requirements for PCB multi-layer circuit board sampling? 1. Neat appearance. When making samples of PCB multi-layer circuit boards, it is necessary to ensure that the product has a smooth appearance without burrs, and that there are no bubbles or delamination between the sample wires and solder mask. Under such appearance cleanliness requirements, PCB multi-layer circuit boards can ensure better soldering
Why is green used in the production of PCB circuit boards? (1) Introduction of professional PCB circuit board production companies in China: Green ink is currently the most widely used and has the longest history, and it is also cheap in the current market. Therefore, green is widely used by manufacturers as the main color of their products. (2) Usually, during the production of PCB circuit boards by PCB sampling companies, there are several processes that must go through the yellow light chamber because the effect of green in the yellow light chamber is better than other colors, but this is not the main reason. When soldering components in SMT, the production of PCB circuit boards involves the process of applying solder paste and mounting, as well as the final AOI calibration lamp. These processes require optical positioning calibration, and a green background color is more effective for instrument recognition. What are the common colors used in the production of PCB circuit boar
How to distinguish the quality of ceramic circuit boards? Ceramic circuit board is a new type of circuit board based on electronic ceramics with various circuit elements attached to the outside. It is widely used in the manufacturing of the electronics industry and has become an important component in electronic product manufacturing due to its good thermal conductivity, strong high-voltage resistance, and stable chemical properties. With the increasing number of products using ceramic circuit boards, it requires certain skills to distinguish a high-quality ceramic circuit board from numerous manufacturers and brands. 1. Check the material parameters of the ceramic board. Due to the fact that ceramic circuit boards use ceramic substrates as the support board for this circuit, the quality of the material used in circuit board sampling has a significant impact on the performance and service life of ceramic circuit boards to a certain extent. Ceramic circuit boards with guaranteed qua
PCB component wiring rules 1. Within the area of ≤ 1mm from the edge of the PCB board and within 1mm around the mounting holes, wiring is prohibited; 2. The power cord should be as wide as possible and not less than 18mil; The signal line width should not be less than 12mil; The CPU input and output should not be less than 10mil (or 8mil); The line spacing shall not be less than 10 mil; 3. Normal through-hole not less than 30mil; 4. Dual in-line insertion: solder pad 60mil, aperture 40mil; 1/4W resistor: 51 * 55mil (0805 sticker); When inserting directly, the solder pad is 62mil and the aperture is 42mil; Infinite capacitor: 51 * 55mil (0805 sticker); During direct insertion, the solder pad is 50mil and the aperture is 28mil; 5. Please note that the power and ground wires should be as radial as possible, and the signal wires should not have looped wiring.
Common problems with RF circuits and digital circuits on the same PCB Insufficient isolation of sensitive lines and noise signal lines is a common problem. As mentioned above, PCB circuit boards have high swing and contain a large number of high-frequency harmonics in digital signals. If the digital signal wiring on the PCB board is adjacent to sensitive analog signals, high-frequency harmonics may couple over. The most sensitive nodes of RF devices are usually the loop filtering circuit of the phase-locked loop (PLL), the external voltage controlled oscillator (VCO) inductor, the crystal oscillator reference signal, and the antenna terminal. These parts of the circuit should be handled with special care. (1) Power supply noise Due to the fluctuation of input/output signals by several volts, digital circuits are generally acceptable for power supply noise (less than 50 mV). However, analog circuits are quite sensitive to power noise, especially to spike voltage and other high-freq
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