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Have you noticed that now more and more of our lighting is using led lighting.What is LED? Compared to the traditional light bulbs, LEDs have lower power consumption, longer lifetime and higher energy efficiency. In the PCB industry,when we say LED PCB, it refers to the pcb used for LED lighting, if you are looking for a suitable LED PCB for your lighting system, this article may bring you something. WHAT ARE LEDS COMPOSED OF?LED is an initial light-emitting diode that produces light when an electric current passes through. LEDs typically have negative and positive electrodes, which generate light in the visible light region.The LEDS are glued to the PCB by soldering process and have electrical connections for lighting.Since light-emitting diodes dissipate a lot of heat when they are in use, when you are designing LED, the metal core is usually the best choice for LED PCB, it is because that it dissipates heat more faster. Among them, the metal material aluminum is the most widely used
To solve the above problems of gilded boards, PCBs using gilded boards mainly have the following characteristics: 1. Due to the different crystal structures formed by depositing gold and gilding, the deposited gold will appear golden yellow and more yellow than gilding, resulting in better customer satisfaction. 2. Due to the different crystal structures formed by sinking gold and gold plating, sinking gold is easier to weld than gold plating, which will not cause poor welding and cause customer complaints. 3. Due to the fact that only nickel gold is present on the solder pad of the sinking gold plate, the signal transmission in the skin effect is not affected by the copper layer. 4. Due to the denser crystal structure of precipitated gold compared to gold plating, it is less prone to oxidation. 5. Due to the fact that only nickel gold is present on the solder pad of the sinking gold plate, it will not produce gold wire causing slight shortness. 6. Due to the fact that only n
As the integration level of ICs increases, PCB sampling manufacturers also have more and more IC pins. The vertical tin spraying process makes it difficult to blow the fine solder pads flat, which brings difficulty to SMT installation; In addition, the shelf life of the tin spray board is very short. And the gilded plate precisely solves these problems: 1. For surface mount processes, especially for 0603 and 0402 ultra small surface mount processes, the flatness of the solder pad directly affects the quality of the solder paste printing process and plays a decisive role in the subsequent reflow welding quality. Therefore, whole plate gilding is often seen in high-density and ultra small surface mount processes. In the trial production stage, the influence of factors such as component procurement is often not that the board is welded immediately upon arrival, but rather that it often needs to wait for several weeks or even months before use. The shelf life of gold-plated boards is l
Single and double-sided PCB circuit boards are the most common and simple PCB boards in the printed circuit board industry. Due to their single panel design and wide circuit design, they are very easy to make. Some simple single panels can be visually inspected without testing costs. During the circuit board quotation process, it was found that there are still a few friends who are not very familiar with the differences between the two, For this reason, I would like to give you a brief introduction on the basic differences between single and double sided circuit boards! What is a PCB single panel: A PCB single panel refers to a circuit board with only one side printed with a circuit, while the other side shows no circuit (note: the other side shows PCB substrate without copper coating); What is a PCB double-sided board: A PCB double-sided board refers to a board that has printed circuits on both sides, and a small number of boards have only one side printed with circuits, while t
By looking at the cut surface of a PCB board to obtain a four layer board, this method is actually quite difficult, and few people have this kind of vision. However, by observing the guide holes, a four layer board can be identified. If the same guide holes can be found on both sides of the PCB board, or if the motherboard or display card is facing the light source, and the position of the guide holes is not transparent, it is a four layer board. A four layer board is a double-sided board that is then pressed together. During the pressing process, PP and copper foil are added to both sides of the double-sided board, and then subjected to high temperature and pressure to form a multi-layer board. Simply put, the four layer board has an inner layer, and in the process, some circuits are etched through the inner layer, which is then pressed together. The double panel is a board that is directly cut from the incoming board and can be drilled for production. How to draw a four layer bo
The purpose of equalizing the line length of high-speed digital PCB boards is to maintain the delay difference of each signal within a certain range to ensure the effectiveness of the system in reading data within the same cycle (when the delay difference exceeds one clock cycle, the data). Typically, the delay difference does not exceed 1/4 clock cycles, and the line delay difference per unit length is also fixed. The delay is related to the line width/line length/copper wire thickness and layer structure, However, line length increases the distributed capacitance and inductance, thereby improving signal quality. Therefore, clock IC pins are usually connected to the RC terminal, but serpentine routing does not play an inductive role. On the contrary, inductance will cause higher harmonic phase shifts in the rising component of the signal, leading to a decrease in signal quality. Therefore, it is necessary to maintain the serpentine spacing at least twice the line width, resulting
1: Process factor: a: Copper foil is excessively etched. The electrolytic copper foil used in the market is generally single-sided galvanized (commonly known as ashed foil) and single-sided copper plating (commonly known as reddened foil). The common copper throwing is generally galvanized copper foil above 70um, while reddened foil and ashed foil below 18um have not undergone bulk copper throwing. b: During the production process, there is a local collision, and the copper wire is detached from the substrate due to external mechanical force. This defect is manifested as poor positioning or directionality. The detached copper wire will have obvious twisting or scratches/impact marks in the same direction. When peeling off the defective copper wire, it can be seen that the color of the copper foil surface is normal, and there will be no side corrosion defects. The peeling strength of the copper foil is normal. c: Unreasonable PCB circuit design, using thick copper foil to design o
The new energy charging pile circuit board is different from other consumer electronic products, as the charging pile circuit board needs to meet high current and high voltage during operation, which is generally not withstood by conventional thin plates. Although all PCB boards are made of copper material, there are still certain differences in grade. Ordinary plates are below TG140, while the substrate used to make the new energy charging pile circuit board needs to be above TG150, which is a high TG material, according to the data, The higher the level parameter, the better the quality of the board. The precautions to be taken when customizing a charging station PCB circuit board include: circuit defects, residual copper on the circuit side, and yellow impedance on the hole side are not allowed. For manufacturers of charging station circuit boards, they also need to implement IPC-III standards to prevent products that do not meet the standards from being eliminated in a timely ma
1. Power cord design: Based on the current of the sample circuit board, the power cord should be designed with a thicker width as much as possible, and the loop resistance should be appropriately reduced to ensure that the direction of the power cord and ground wire is consistent with the direction of data transmission. This design helps to enhance noise resistance. 2. Ground wire design: Digital ground and analog ground should be designed separately. If there are both logical and linear circuits on the circuit board, they should be separated as much as possible during design. Even for low-frequency circuits, single point parallel grounding should be used as much as possible. When there are difficulties in actual wiring, partial series connection can be used before parallel connection to ground. High frequency circuit boards should be grounded in series with multiple points, and the grounding wire should be short and leased. Grid shaped large area grounding foil should be used aro
① Dielectric constant: Dk needs to be small and stable. Generally, the smaller Dk, the faster the signal transmission speed, which is inversely proportional to the square root of the dielectric constant of the substrate. The larger Dk, the more likely it is to cause signal transmission delay. ② Dielectric loss: At the same time, the smaller the Dk, the better the signal transmission quality, and the smaller the dielectric loss, the smaller the signal loss. ③ The thermal expansion coefficient of copper foil should be consistent as much as possible, with low water absorption, other heat resistance, chemical resistance, impact strength, peel strength, and other aspects that must be well protected. Normally, high-frequency boards are defined as above 1GHz. Currently, most of the high-frequency circuit board substrates produced are fluorine based dielectric substrates, such as Teflon, which are mostly used for frequencies above 5GHz. Other FR4 substrates are used between 1GHz and 10G
① Benefits: Both high-frequency circuits and low-frequency power supply circuits have voltage gain and output power harvesting effects. Resonant differential amplification circuits refer to the resonant frequency f0, and for fiber optic broadband differential amplification circuits, they refer to a frequency range. ② Pass band: The concept is quite different from that of low-frequency power circuit boards. For resonant differential amplification circuits, most of them are the values between the two corresponding frequencies when the normalized vibration amplitude of the resonance frequency f0 decreases to 0.707; For fiber optic broadband amplification circuits, it refers to the corresponding meaning relative to a certain frequency. ③ Selectivity: Selectivity is mainly aimed at resonant amplification circuits, which characterizes the selection of useful signals and the suppression ability of useless signals in the circuit. It is usually measured using rectangular coefficient and s
At present, the common colors of PCB circuit boards in the market are green, black, blue, yellow, purple, red, and brown, and recently white and pink PCBs have also appeared. So, why do PCB circuit boards have different colors? Have you noticed that most circuit boards are green, while other colors are rare? Why is this? Next, the editor of the circuit board manufacturer will spread a wave of knowledge about circuit boards to everyone~ In the production of PCB boards, the final surface of the copper layer is smooth and unprotected, whether it is additive or subtractive. Although the chemical properties of copper are not as good as those of aluminum, iron, and magnesium, pure copper is prone to oxidation under water conditions when in contact with oxygen. However, the thickness of the copper layer in PCB circuit boards is very thin, and the oxidized copper can become a poor conductor of electricity, greatly damaging the electrical performance of the entire PCB. In order to preven
PCB, also known as printed circuit board, is a provider of electrical connections for electronic components, and its design mainly involves layout design; The main advantage of using circuit boards is that they greatly reduce wiring and assembly errors, improve automation levels and production labor rates. The existence of PCBs has a history of over 100 years. PCBA: PCBA is the entire process of SMT loading on an empty PCB board, followed by DIP plugins. The differences between them include: 1. Different functions PCBs can make programs that cannot run independently a unit that runs independently. The excellent circuit design of PCBA can achieve good circuit performance and heat dissipation performance. 2. Essentially different PCBA generally refers to a processing process, which can also be said to be a finished circuit board, that is, a PCB that is completed after processing.
The so-called blind hole circuit board refers to non drilled holes. The difference between blind holes and through holes is that through holes are holes drilled through each layer. When making blind hole boards, drilling is done before pressing, while through holes are drilled after pressing. What basic knowledge do you need to know in the manufacturing of blind hole PCB circuit boards Blind hole PCB circuit board ① Drill tape: Select through holes as unit reference holes. Each blind hole drill tape needs to select a hole and identify its corresponding unit reference hole coordinates, and note which drill tape corresponds to which layers. When the laser hole is sleeved with the inner buried hole, even if the holes of the two drill tapes are in the same position, it is necessary to confirm with the customer. Move the position of the laser hole to ensure electrical connection, and do not handle it arbitrarily based on experience. ② Process holes: The inner layer of ordinary multi-
1. Heat dissipation through the circuit board itself: Currently, the most widely used substrates for printed circuit boards are copper clad/epoxy glass cloth substrates, phenolic resin glass cloth substrates, paper based copper clad substrates, etc. Although these substrates have good electrical and processing properties, their heat dissipation is poor, and they are still not competent for some products with high current requirements. With the continuous updating of precision products, The volume of the PCB board is also decreasing, but the precision is constantly increasing. If only the surface is used for heat dissipation, it is far from enough. The best way to solve this problem is to improve the heat dissipation ability of the PCB board itself, which is directly in contact with the heating element, and transmit heat out through the circuit board itself. 2. When designing a PCB circuit board, a reasonable circuit layout can also achieve heat dissipation. Apart from the poor the
The color of the solder mask layer mainly depends on the color of the solder mask ink. Green ink is currently the most widely used and the cheapest in the market. In fact, the soldering ink on the market is not only limited to green, but also has various colors such as red, blue, purple, black, and yellow. However, green is the most common, and the main reason is that using green soldering ink has the following advantages: it is easy for optical positioning correction. The production process of the circuit board itself includes the STM welding process, which requires soldering and final AOI verification. These processes require optical positioning calibration, and the green background color has a better recognition effect on the instrument. The visual effect is better in the yellow light room. The entire PCB board product undergoes processes such as board making and SMT during the production process. Usually, when circuit boards are used in the production and processing of electroni
FPC flexible circuit board is a highly reliable and excellent flexible printed circuit board made of PI polyimide or polyester film as the substrate. It has the characteristics of high wiring density, light weight, thin thickness, and good bending performance. PI, as a special engineering material, has been widely used in fields such as aviation, aerospace, microelectronics, nanomaterials, liquid crystals, separation membranes, lasers, etc. The long-term use temperature is between -200 ℃ and 426 ℃. PI polyimide is common in FPC flexible circuit boards, as it exists in substrates, covering films, and even reinforcement. Some people may be confused about this, so today let's discuss the difference between them? The functional differences between the substrate, covering film, and PI reinforcement of FPC flexible circuit boards are as follows: 1 PI substrate: For FPC flexible circuit board substrates, there are two types: adhesive substrate and non adhesive substrate. PI polyimide is
So, what are the components of FPC flexible circuit boards? In the structure of FPC flexible circuits, the materials composed of flexible copper clad laminate (FCCL), covering film, adhesive film, etc. Flexible Copper Clad Laminate (FCCL): The common film materials for flexible copper clad laminates include polyimide film (PI), polyester (PET), polyethylene naphthalate (PEN), liquid crystal display polymer (LCP), and other polymer plastic films. In FPC flexible circuit boards, copper clad boards mainly play three roles: conductivity, insulation layer, and support points. Covering film: It is composed of organic chemical plastic film and adhesive, and its function is to maintain a part of the flexible power circuit electrical conductor that has already been carried out. There are different types of adhesive films and adhesive types, as well as thickness specifications and models for adhesive films. Adhesive film: It is formed by pouring adhesive on two or one side of a substrate f
Regarding FPC soft boards, also known as flexible circuit boards, they are actually a type of printed circuit board, but there are significant differences from traditional printed circuit boards. Therefore, they are referred to as FPC soft boards, also known as flexible circuit boards. FPC generally uses PI as the substrate and is a flexible material that can be bent or flexed arbitrarily. FPC soft boards are usually used for links that require repeated bending and some small components, but now it's not just that. Currently, smartphones are considering bending prevention, which requires the use of FPC soft boards as a key technology. PCB is the so-called printed circuit board, usually referred to as PCB hard board, which is the support body in electronic components and is a very important electronic component. PCB hard boards usually use FR4 as the substrate, also known as FR4 circuit boards, and cannot be bent or bent. PCB hard boards are usually used in places that do not requi
The trend research on PCB sampling technology began to be implemented at the end of 2011, including English and Chinese versions. 41 PCB sample manufacturing companies participated in the survey, including dominant companies from Asia, Europe, and North America. They hold a 16.5% share of the global PCB market. The IPC research sample is representative of the global industry in terms of company size and product portfolio. Among the companies studying the trend of PCB sampling technology, the production of high-density interconnect (HDI) boards is expected to increase by 26% between 2011 and 2014. Stacking and interleaving micropores technology will also be widely used, thereby affecting the performance of any layer of micropores and any through-hole. With trends driven by miniaturization and high-speed technology, surveys have shown that the two most common factors limiting circuit scale miniaturization are solder mask pattern alignment and assembly. Most companies are evaluating
Printed circuit boards (PCBs), also known as circuit boards, are important electronic components and are known as the "mother of electronic components". 1. Traditional circuit boards are also known as printed circuit boards and printed circuit boards, as they are made by printing corrosion-resistant agents. At present, most circuit boards are coated with anti-corrosion agents (laminated or coated), and after exposure and development, the circuit board can be etched. 2. Circuit boards include single panel, double-sided board, and multi-layer board. In the most basic PCB, components on one side and wires on the other side are called single panels. The double-layer panel is covered with copper on both sides, and the lines between the two layers can be connected through through-holes to form the required network connection. Multilayer board refers to a printed board with three or more layers of conductive patterns, with insulating materials in the middle, and conductive patterns connec
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