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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
1. It is strictly prohibited to use grounded testing instruments and equipment to test the power amplifier PCB board without an isolation transformer. When coming into contact with equipment with high output power or unfamiliar with the nature of the power supply used, it is necessary to first determine whether the chassis of the machine is live, otherwise it is easy to cause a power short circuit with the live equipment on the chassis, affecting the integrated circuit, and causing the fault to expand. 2. When testing the power amplifier PCB board, attention should be paid to the insulation performance of the electric soldering iron. When testing, it is necessary to confirm that the soldering iron is not live. It is best to ground the shell of the soldering iron, and it is safer to use a low-voltage circuit iron of 6-8V. 3. It is very important to understand the working principle of integrated circuits and their related circuits before testing the power amplifier PCB board. It is
Single panel On basic medical PCB boards, the parts are concentrated on one side, while the wires are concentrated on the other side. Due to the fact that the wires only appear on one side, this type of medical PCB board is referred to as single sided. Due to the many strict restrictions on the design of a single sided circuit board (as it only has one side, the wiring cannot cross and must revolve around a separate path), only early circuits used this type of circuit board. Double-sided board This type of circuit board has wiring on both sides, but if wires are used on both sides, there should be appropriate circuit connections between the two sides. The "bridge" between these circuits is called a through hole. Through holes are small holes filled or covered with metal on medical PCB boards, which can be connected to wires on both sides. Because the area of a double-sided board is twice that of a single panel, it solves the problem of staggered wiring (which can be transmitted
PCBA test stand is a device used to test PCBA finished products. When making PCBA test racks, PCBA processing plants usually need to provide Gerber files and PCBA samples to facilitate the production of test racks. For the current PCBA test bench, only a few pressure plate buckles are installed on the test bench, and the PCBA is fixed by a thimble and pressure plate buckle. During the PCBA function test, press the PCBA into the pressure plate buckle with both hands. Due to uneven force or insufficient compression, PCBA can easily cause poor contact between the testing needle and PCBA, seriously affecting testing efficiency and accuracy; If too much force is applied, it is easy to deform or damage the PCBA when pressing down, and it is also easy to damage the test needle of the testing frame, causing significant losses. 1、 Material preparation After determining the plan based on the information, it is necessary to prepare hardware materials (electronic components), relevant additi
The circuit layout of HDI high-frequency boards is extremely dense, and the production price is slightly higher than that of conventional circuit boards. Only some high-end electronic products will use HDI high-frequency circuit boards, and HDI high-frequency boards include all "blind hole boards" and "buried hole boards". So, what are the differences between identifying blind hole boards and buried hole boards! ① Blind hole: refers to a through hole that connects the inner layer of the PCB to the surface layer of the PCB, but this type of hole does not penetrate the entire board. Buried hole: a through-hole that only connects the wiring between the inner layers, which cannot be seen from the surface of the PCB alone. In this regard, PCB boards with buried blind holes may not necessarily be HDI circuit boards, but HDI high-frequency boards must have blind holes. ② Taking a six layer circuit board as an example: the first/second order refers to PCB boards that require laser drilli
① Hole wall copper thickness: A 25 micron hole wall copper thickness effectively enhances the reliability of PCB boards and improves the Z-axis expansion resistance. ② No welding/patching repair: Perfect for no welding repair and open circuit patching repair, which can effectively ensure the reliability and safety of circuit boards. ③ IPC specifications: For some manufacturers of high-end and high-quality PCB circuit boards, exceeding IPC specifications for cleanliness can not only improve customer satisfaction and trust, but also gain a certain influence in the industry. ④ Service life: Strictly control the surface treatment of each type of PCB circuit board to ensure its solderability and reliability meet industry standards, and reduce the risk of moisture intrusion. ⑤ Substrate: According to the company's positioning standards, select internationally renowned boards to improve product reliability and known performance. ⑥ Ink: Ensure that the solder mask material used compli
Almost all powered products cannot do without power circuit boards, but due to different application areas, there are differences in customizing power circuit boards in terms of current requirements, product specifications, surface treatment processes, and so on. Firstly, let's understand what types of power supply PCBs include: ① switching power supply ② monitoring power supply ③ high-frequency power supply ④ LED power supply ⑤ production equipment power supply ⑥ digital electronic power supply, etc. For these common power supply circuit boards, the following will explain different types of power supply circuit board products and different process choices. 1. Mobile power circuit boards: These types of circuit boards are usually double-sided or four layer boards, with normal copper thickness, simple circuit design, and surface treatment processes mostly based on tin spraying. 2. Switching power supply circuit boards: Most of these circuit boards are double-sided, with a copper
1um=? Mm, 1mil=? The commonly used unit conversion formula for MM circuit board PCB is compiled by Suzhou circuit board sampling manufacturer below. Let's take a look together! For personnel engaged in the PCB industry, it is inevitable to encounter various units of data. Conversion between various units is also frequently needed. It is often necessary to search for conversion values. In order to facilitate the use and learning of PCB practitioners, PCB engineering, PCB electronic engineers, and other personnel. Below are examples of conversion values between various units for your reference. Both Chinese and English abbreviations are indicated. We believe that the unit conversion below is for everyone to keep and learn. Below are examples of conversion values between various units for your reference. Both Chinese and English abbreviations are indicated. We believe that the unit conversion below is for everyone to keep and learn Common units for line width/line spacing/coating th
Previously, the article discussed the packaging and printing methods of aluminum plated films, as well as the principles of ink selection and bonding composite. But this does not mean that only white ink with a high content of resin binder can have sufficient composite adhesion strength. Other factors that affect the adhesion strength of white ink include surface active dispersants and anti sinking, friction resistant wax materials in the ink system, as well as static electricity in the ink itself. The Suzhou circuit board sample manufacturer tells you that once the adhesive is applied to the surface of a white ink film containing surface active dispersants or anti sinking, friction resistant wax additives, the repulsive or almost tensile wax will cause the adhesive layer on the surface of the substrate to form a uniform point like substance, resulting in low-quality packaging printed products with poor composite fastness or low composite strength. Secondly, due to the use of pack
The main purpose of vacuum aluminum coating film is to replace pure aluminum foil composite, giving soft packaging printed materials an elegant silver white luster, and reducing packaging printing costs while improving the barrier and shading properties of soft packaging film bags (aluminum coating film instrument is 0.4~0.6) μ m. Only about 1/150) 25% of the amount of pure aluminum foil used. The PCB sampling manufacturer tells you that there are two common vacuum aluminum plating methods: One is vacuum aluminum plating after printing, which involves reverse inner printing on the surface of the thin film, followed by aluminum plating, and then composite with the bottom film; The second is to directly imprint on the surface of the thin film, and then dry composite it with the vacuum aluminum plated bottom film. But this method requires the use of materials such as CPP and PE with good heat resistance and heat sealing for the bottom film. No matter what method is used, the compo
1. Industry regulatory authorities and regulatory system The Ministry of Industry and Information Technology of China is the competent department in charge of the printed circuit board industry. Its main responsibilities include formulating and organizing the implementation of industry plans, plans, and policies for the industrial and communication industries, proposing policy recommendations for optimizing industrial layout and structure, drafting relevant laws and regulations, formulating regulations, drafting industry technical specifications and standards, and organizing their implementation, guiding industry quality management work. The Electronic Information Department under the Ministry of Industry and Information Technology of China is responsible for industry management of electronic information product manufacturing; Organize and coordinate the development and production of major system equipment, microelectronics and other basic products, and organize and coordinate the
Negative film of circuit board: Generally speaking, it is the tenting process that uses acidic etching negative film because after the film is made, the desired circuit or copper surface is transparent, while the unwanted parts are black. After exposure by the circuit process, the transparent part hardens chemically due to the exposure of the dry film inhibitor to light. The subsequent development process will wash away the dry film that has not hardened, So in the etching process, only a portion of the copper foil (the black part of the film) that has been washed off by biting off the dry film is retained, while the circuit (the transparent part of the film) that belongs to our desired circuit (PCB sample) is retained. We will tell you about the positive of the circuit board. Generally, this is the pattern process we are talking about, and the solution used is alkaline etching positive. If viewed from the negative, the desired circuit or copper surface is black, while the other pa
The earlier the signal integrity (SI) problem is solved, the higher the efficiency of the design, which can avoid adding termination devices only after the circuit board design is completed. There are many tools and resources available for SI design planning. This article explores the core issues of signal integrity and several methods to solve SI problems, ignoring the technical details of the design process. With the increase of IC output switching speed, almost all designs have encountered signal integrity issues regardless of the signal cycle. Even if you haven't encountered SI issues in the past, as the working frequency of the circuit increases, you will definitely encounter signal integrity issues in the future. The signal integrity problem mainly refers to the phenomenon of signal overshoot and damping oscillation, which are mainly functions of IC driving amplitude and jump time. That is to say, even if the wiring topology remains unchanged, as long as the chip speed beco
1. Engineering design: Precautions for printed circuit board design: A. The arrangement of interlayer semi cured sheets should be symmetrical, for example, for a six layer board, the thickness and number of semi cured sheets between layers 1-2 and 5-6 should be consistent, otherwise it is easy to warp after lamination. B. Multi layer core boards and semi cured sheets should use products from the same supplier. C. The area of the circuit diagram on the outer A and B sides should be as close as possible. If side A is a large copper surface and side B only runs a few wires, this type of printed circuit board is prone to warping after etching. If the area difference between the two sides of the circuit is too large, independent grids can be added to the sparse side for balance. 2. Drying board before cutting: The purpose of drying the copper-clad board before cutting (150 degrees Celsius, time 8 ± 2 hours) is to remove moisture from the board and completely cure the resin inside t
1、 Why do circuit boards require a very flat surface The circuit board prototype manufacturer tells you that if the printed circuit board is not flat on the automated insertion line, it will cause inaccurate positioning, prevent components from being inserted into the holes and surface mounting pads of the board, and even damage the automatic insertion machine. The board where the components are installed is bent after welding, making it difficult to cut the component legs flat and neat. The board cannot be installed on the chassis or socket inside the machine, so it is also very troublesome for the assembly plant to encounter board warping. At present, printed boards have entered the era of surface installation and chip installation, and assembly plants are bound to have increasingly strict requirements for board warping. 2、 Standards and testing methods for warpage According to the American IPC-6012 (1996 edition), the allowable large warpage and distortion for surface mount
The positioning of CNC milling is to use positioning pins to position the printed circuit board to be processed on the workbench of the milling machine, so as to conveniently and accurately process the shape of the printed circuit board. Require simple and reliable positioning, capable of quickly loading and unloading boards while eliminating chips. The manufacturer of circuit board samples tells you that there are various positioning methods, such as the design of reciprocating workbenches for some milling machines. When one worktable is being processed, the other worktable loads and unloads the board. There is also a method of using two sets of milling positioning pads. When one milling positioning pad is processed on the CNC milling workbench, the other milling positioning pad is loaded and unloaded on the platform. The exchange between the two only takes a few seconds. The CNC milling worktable itself is a positioning plate, which is an aluminum alloy plate fixed with pins and
In circuit design, we are generally concerned about signal quality issues, but sometimes we limit our research to signal lines and treat power and ground as ideal situations. Although this approach can simplify the problem, it is no longer feasible in high-speed design. Although the direct result of circuit design is reflected in signal integrity, we cannot ignore power integrity design as a result. Because the integrity of the power supply directly affects the signal integrity of the subsequent PCB board. Power integrity and signal integrity are closely related, and in many cases, PCB sample manufacturers believe that the main cause of signal distortion is the power system. For example, excessive ground rebound noise, inappropriate design of decoupling capacitors, severe circuit impact, poor separation of multiple power sources/ground planes, unreasonable geological design, uneven current, and so on. 1) Power distribution system Power integrity design is a very complex task, but i
In commercial production, there are two laser technologies available for laser drilling. The wavelength of CO2 laser is in the far-infrared band, and the wavelength of ultraviolet laser is in the ultraviolet band. CO2 laser is widely used in the production of industrial micro through-holes on printed circuit boards, with a requirement that the diameter of the micro through-hole be greater than 100 μ (Raman, 2001). For the production of these large aperture holes, CO2 laser has high productivity because the punching time required for CO2 laser to produce large holes is very short. UV laser technology is widely used in diameters less than 100 μ In the production of micro pores in m, with the use of miniaturized circuit diagrams, the pore size can even be less than 50 μ M. Ultraviolet laser technology in the production of diameters less than 80 μ The yield of m holes is very high. Therefore, in order to meet the increasing demand for microporous productivity, many manufacturers have b
CO2 laser effectively removes dielectrics, even non-uniform glass reinforced dielectrics. However, a single CO2 laser cannot create small holes (less than 75 μ m) In addition to removing copper, Suzhou circuit board sample manufacturers believe that there are also a few exceptions, which are that it can remove pre processed 5 μ Thin copper foil below m (Lustino, 2002). UV laser can create very small holes and remove all ordinary copper streets (3-36 μ m. 1oz, even electroplated copper foil. UV laser can also remove dielectric materials separately, but at a slower speed. Moreover, for non-uniform materials, such as reinforced glass FR-4, the effect is usually not good. This is because only when the energy density is increased to a certain extent can the glass be removed, which will also damage the inner solder pads. Due to the fact that the stick laser system includes ultraviolet laser and CO2 laser, it can achieve better results in both fields. UV laser can complete all copper foil
1. Report the results of the work The leader who lifts the heavy weight is the favorite. When reporting work, please remember to report the result to the leader first, and the result thinking is the first thinking. 2. Ask for work plan Please ensure that at least two programs are given to leaders, and express their views and effective suggestions. Don't let the leader do the quiz questions, but let the leader do the multiple-choice questions. Don't ask the leader how to do this thing, what to do, but ask, I have a plan, you can listen to it and see how it goes! 3. Summarize the work process and find three points To do a work summary, it is necessary to describe the process, not only to have a clear sequence and logic, but also to find out the key points, mistakes, and reflection points in the process. 4. Arrange work standards and clarify customer requirements Layout work must be clear about customer requirements and quality standards, otherwise subordinates will not know ho
After the customer's plug-in test, it is found that the via hole (via hole) is not connected. The test can be carried out normally before the plug-in, and the appearance has no drilling deviation phenomenon, which is mainly caused by the following five reasons: First: the hole copper is not enough; Second: the roughness of the hole wall is too large Third: Drilling dust plug holes Fourth: drilling broken knife to make up holes Fifth: poor solder mask plug hole In terms of controlling the problem of through-hole failure, the hole copper is the most important link. The automatic sinking copper line of our Honglian circuit is not small: Detection: The detection method of immersion copper wire is mainly backlight series detection. The number of series is more than 9 to be qualified to ensure the quality of copper immersion and hole formation. The detection methods include deposition speed force detection (copper layer thickness in standard time); glue removal speed force (this
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