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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
Pcb circuit board manufacturing refers to the trial production of printed circuit boards before mass production, mainly refers to the process that electronic engineers design circuits, complete PCB, and then carry out a small amount of trial production to the factory. This is the Chinese name for PCB, which is printed circuit board, also known as printed circuit board. It is an important electronic component, the support of electronic components, and the electrical connection provider of electronic components. It is called a "printed" circuit board because it is made using electronic printing technology. Pcb circuit board manufacturing refers to the trial production of printed circuit boards before mass production, mainly refers to the process that electronic engineers design circuits, complete PCB, and then carry out a small amount of trial production to the factory. This is the manufacturing of PCB circuit boards. The production quantity of PCB samples usually does not have a spe
1. To prevent short circuits caused by tin penetrating through the component surface through the through hole during PCB wave soldering; Especially when we place the via hole on the BGA pad, we must first make a plug hole and then gild it to facilitate BGA welding. 2. After the surface mounting and component assembly of the electronic factory are completed, the PCB needs to be vacuumed on the testing machine to form negative pressure: 3. Prevent surface solder paste from flowing into the holes, causing false soldering and affecting the installation of PCB circuit boards; 4. Prevent solder beads from popping out during peak soldering, causing short circuits on the PCB circuit board; 5. Avoid flux residue in the through-hole
If a PCB circuit board is used in a humid environment, the air contains a large amount of moisture. When the moisture is too high, it will turn into water droplets and fall onto the PCB circuit board. After the water droplets scatter on the circuit board, they will attach to various pins or printed wires of electronic components. After the printed wire is soaked with water droplets, especially when the signal transmission line is relatively small and soaked for a period of time, there will be mold breakage of the printed wire, causing the circuit board to malfunction during the next operation. The causes of circuit board failures caused by moisture are classified into three categories: 1. Causing changes in circuit parameters in the PCB circuit board, leading to PCB circuit board failure; 2. Causing the circuit in the PCB circuit board to be in a short circuit state, causing the PCB circuit board to malfunction; 3. Causing open circuit in signal processing or transmission line
1、 Introduction: With the continuous improvement of human requirements for living environment, the environmental issues involved in PCB production process are particularly prominent. The topic of lead and bromine is currently the most popular; Lead-free and halogen-free technologies will affect the development of PCBs in many ways. Although at present, the changes in the surface treatment process of circuit boards are not significant and may seem distant, it should be noted that long-term slow changes will lead to significant changes. With the increasing demand for environmental protection, the surface treatment process of PCBs is bound to undergo significant changes in the future. 2、 The purpose of surface treatment is to ensure good weldability or electrical performance, which is the most basic purpose of surface treatment. Due to the tendency of copper in nature to exist in the form of oxides in the air, it is unlikely to remain the original copper for a long time, so other tr
The switch regulator used for voltage conversion uses inductance to store energy when it falls. These inductors are usually very large in size and must be positioned in the printed circuit board (PCB) planning of the switch regulator. This task is not difficult, as the current passing through the inductor may change, but it is not an instantaneous change. Changes can only be continuous and usually relatively slow. The switching regulator switches current back and forth between two different paths. This switching is very fast, and the detailed switching speed depends on the duration of the switching edge. The wiring through which switching current flows is called a thermal circuit or AC current path, which conducts current in one switching state and does not conduct current in another switching state. In PCB planning, the thermal circuit area should be small and the path should be short to minimize parasitic inductance in these wiring. Parasitic wiring inductance can generate useles
Printed circuit boards are the most active industry in the contemporary electronic component industry, and their industry growth rate is generally about 3 percentage points higher than that of the electronic component industry. It is expected to maintain rapid growth in 2006, with demand upgrading and industrial transfer being the basic driving forces for industry development, while varieties such as HDI boards, flexible boards, and IC packaging boards (BGA, CSP) will become the main growth points. In 2003, the output value of printed circuit boards in China was 50.069 billion yuan, a year-on-year increase of 333%, surpassing the second largest in the world, the United States, for the first time. In 2004 and 2005, China's PCB output value still maintained a growth rate of over 30%, estimated to reach 86.9 billion yuan in 2005, far exceeding the growth rate of the global industry. Flexible circuit boards are rapidly developing towards miniaturization in electronic devices represen
The suitability of PCB circuit boards in terms of system signal, connection distance, and capacitive load is considered before deciding whether to use transmission lines. What types of transmission lines are commonly used in PCB circuit boards? The main types of transmission lines for PCB circuit boards are: (1) Coaxial cables and twisted pair cables: They are often used for the connection between PCB circuit board transmission systems and systems. The characteristic impedance of coaxial cables is typically 50 Ω and 75 Ω, while twisted pair cables are typically 110 Ω. (2) Microstrip on PCB The Microstrip is a strip conductor (signal line). It is separated from the ground plane by a dielectric. If the thickness, width, and distance from the ground plane of a line are controllable, its characteristic impedance can also be controlled. (3) Strip lines in printed boards A strip line is a copper strip line placed between two conductive planes in the middle of a dielectric medium. I
1. Pad design (1) When designing plug-in component pads, the pad size should be designed appropriately. If the solder pad is too large, the solder spreading area is large, and the formed solder joints are not full, while the surface tension of the smaller solder pad copper foil is too small, and the formed solder joints are non wetting solder joints. The fit gap between the aperture and the component lead is too large, which is prone to false soldering. When the aperture is 0.05-0.2mm wider than the lead and the diameter of the solder pad is 2-2.5 times the aperture, it is an ideal welding condition. (2) When designing solder pads for SMD components, the following points should be considered: in order to eliminate the "shadow effect" as much as possible, the solder end or pin of SMD should be facing the direction of the tin flow to facilitate contact with the tin flow and reduce false soldering and solder leakage. For smaller components, they should not be placed behind larger co
Sometimes, PCB circuit board substrates can cause open circuits, which are mainly caused by: 1. There are scratches on the copper clad plate before entering the warehouse; 2. The copper clad plate was scratched during the cutting process; 3. The copper clad plate was scratched by the drilling nozzle during drilling; 4. The copper clad plate was scratched during transportation; 5. The surface copper foil was damaged due to improper operation during the stacking of boards after copper deposition; 6. The copper foil on the surface of the production board was scratched when passing through the leveling machine. Improvement methods: 1. Before entering the warehouse, the IQC must conduct spot checks on the copper clad PCB circuit board substrate to check if there are scratches or exposed substrate on the board surface. If there are any, the supplier should be contacted in a timely manner to make appropriate treatment based on the actual situation. 2. The PCB circuit board substr
After decades of development, the PCB circuit board industry has become extremely mature in terms of technology. Key technologies such as drilling, copper deposition, exposure, development, and etching have been well controlled by automation equipment, making PCB circuit board factories an equipment and fixed asset intensive industry. Business owners have to come up with low price strategies in the fierce market competition. Therefore, the market will be full of the phenomenon of Gresham's law. How to stand out from fierce market competition? It is worth every manager's deep thinking.The rise of any industry is first about creativity, then about the market, and finally about quality. At the beginning, insightful individuals will first identify potential market opportunities, enter the market first, and quickly gain profits. Then more and more people will discover such business opportunities and enter the market competition. Finally, when the industry is saturated, end customers can fre
The competition of enterprises is diversified, from the previous short Plate theory theory to the current long Plate theory theory. Faced with fierce market competition, limited resources of enterprises can only be concentrated on a certain board, making it bigger and stronger. This has led many electronic product companies to only focus on research and development and sales, outsourcing PCBA electronic manufacturing to professional companies, and no longer trying out material procurement, outsourcing processing, supply chain management, and so on that they are not good at. The benefit of doing so is to reduce manpower investment and management costs, as well as the risk losses caused by one's lack of expertise. Careful people will find that in recent years, more and more companies have begun to seek professional PCBA electronic manufacturing resources.Another driving factor is the country's advocacy for mass entrepreneurship and innovation, which has led to an increasing number of sma
(1) Although the wiring spacing and wiring width are consistent, the spacing of Coupon Test point is fixed at 2.54mm (to meet the spacing of test probes), and the spacing of the end of the actual wiring in the board (i.e., the golden finger) is variable. With the emergence of QFP, PLCC, and BGA packages, the pin spacing of some chips is far less than 2.54mm (i.e., the spacing of Coupon Test point).(2) Coupon wiring is an ideal straight line, while the actual wiring on the board is often designed and produced according to actual needs. PCB designers and production personnel can easily idealize Coupon's wiring, but the actual wiring on the PCB board may undergo irregular changes due to practical needs.(3) The positions of Coupon and the actual wiring inside the board are different on the entire PCB board. Coupons are located in the middle or edge of the PCB board and are often removed by the manufacturer when the PCB board leaves the factory. The actual positions of the wiring inside the
(1) The distance between the Test point of Coupon is different from that of the cabling of Coupon, which will cause impedance discontinuity between the Test point and the cabling. This will result in different impedance test results.(2) The impedance changes reflected by curved wiring and ideal wiring are inconsistent. The characteristic impedance at the bending and turning point of the wiring is often discontinuous, while Coupon's idealized wiring cannot reflect the impedance discontinuity caused by the bending of the wiring.(3) Coupon and real wiring have different positions on the PCB board. Currently, PCB boards are designed with multi-layer wiring and require pressing during production. When a PCB board is pressed, the pressure on different positions of the board cannot be consistent, and the thickness of the dielectric layer at different positions will also vary. As a result, the dielectric constant of the PCB board made from this method often varies at different positions, and t
(1) Visual inspection PCB boards generally undergo electrical testing before leaving the factory. We inspect the appearance of PCB boards through visual inspection methods upon receipt, including warping, scratches, flying wires, broken wires, ink blockage, unclear screen printing, solder pad oxidation, uneven solder pads, blocked vias, and burrs on the board edges (2) Dimensional measurement Use a micrometer to measure the thickness, shape, dimensions, and V-CUT of the PCB board to ensure compliance with the Gerber file design. (3) Furnace temperature test Many PCB boards, due to poor process control, experience yellowing and warping when subjected to high temperatures such as reflow soldering. When outsourcing processing, it is essential to require the PCB board to undergo furnace temperature testing first to avoid mass welding defects or affecting the future reliability and durability of the product. Especially for PCB boards with high TG design, this inspection is particular
After the electronic product development project is finalized, engineers and procurement departments need to estimate the price of the entire PCBA circuit board. The simple method is to send the design BOM and GERBER files to different suppliers to obtain quotations for comparison. But the problem is that when there is a significant difference in the price of PCBA we obtain, we cannot determine the true and accurate price. Because different suppliers may substitute materials or make random estimates, which can mislead your prices. At this time, it is particularly important to self estimate the price of PCBA processing. PCBA processing price mainly includes: component cost, PCB cost, SMD processing cost, and basic Gross profit of manufacturing enterprises. The cost of components can be inquired through the public Open platform (Tradegate, Datagate), and its open price can be used as a reference. For large goods above 10K, it can generally be estimated at 70% of the open price. The
The steel mesh tension standard has reference indicators in the IPC electronic acceptance standard. Generally, a steel mesh tension tester is used, placed at a distance of 15-20cm from the edge, and 5-8 points are selected, with each square centimeter having a tension greater than 35-50N. Every time the steel mesh is used online, the tension must be re measured. The testing steps are as follows: Appearance inspection of steel mesh: whether there are scratches, burrs, damages, etc Zero the tension gauge and tighten the zero scale screw The steel mesh should be placed horizontally on the workbench and should not be pressed by hand during testing Select a Test point to check whether the test value meets the standard Fill out the "Steel Mesh Tension Test Record Form" Steel mesh cleaning Installation and use on solder paste printing machine
1. Does the voltage and current meet the design requirements Under normal circumstances, after each PCBA is powered on, even without burning the MCU program, various voltage differences, current conduction, etc. can be generated through circuit connections. PCB designers will deploy different Test point on the PCBA board, and these Test point can be connected to the ICT or FCT test rack to detect voltage and current data. 2. After burning MCU program, input user actions and check whether the output is normal After the PCBA board burns the MCU program, the user executes an action (such as long pressing the switch for 3 seconds), and the MCU will issue a logic command to control the circuit's switch, thereby achieving the design requirements. In this case, PCBA online test can detect whether the input and output of this action are normal. 3. Full functional testing at the product level This online testing is relatively advanced, basically simulating more than 80% of the core fun
Engineering and technical personnel should understand the necessary production processes and master relevant software production, including common circuit design software such as Altium Designer, Pads2000, Autocad, etc. They should also be familiar with necessary CAM software such as View2001 and CAM350; GCCAM, etc., should include PCB design input, which can edit, correct, repair, and assemble circuit graphics, use magnetic disks as the dielectric material, and output automated data for photo drawing, drilling, and testing. An important aspect of the success of the laser light drawing machine market is providing manufacturers with a large amount of technical strength in engineering production. At the same time, we have also seen a large demand for engineering and production personnel from Jianhe PCB manufacturers, as well as an increasing demand for the level of engineering and technical personnel. Therefore, it prompts us to continuously improve our technical level in order to m
The level of PCB engineering production can reflect the design level of designers, as well as the production process and technical level of printed board manufacturers. At the same time, as the PCB engineering production integrates Computer-aided design and auxiliary manufacturing, it requires extremely high precision and accuracy, otherwise it will affect the electrical performance of the final electronic products on board, and may cause errors in serious cases, which will lead to the scrapping of the whole batch of printed board products, delay the manufacturer's contract delivery time, and suffer economic losses. Therefore, as a PCB engineering manufacturer, one must always bear in mind their significant responsibilities and not take them lightly. They must be careful, serious, and meticulous. When processing PCB design files, it is important to carefully check whether the received files comply with the rules established by the designer? Can it meet the requirements of PCB manuf
The circuit board has a history of over 60 years since its invention. History has shown that without circuit boards and electronic circuits, flight, transportation, atomic energy, computers, aerospace, communication, home appliances... all of these cannot be achieved. The truth is easy to understand. Chips, ICs, and integrated circuits are the grain of the electronic information industry. Semiconductor technology reflects a country's level of industrial modernization and guides the development of the electronic information industry. The electrical interconnection and assembly of semiconductors (integrated circuits, ICs) must rely on circuit boards. As the author of Japan's "Circuit Board Collection", Masao Kobayashi, said, "Without computers and data, electronic devices are like an ordinary box; without semiconductors and circuit boards, electronic components are like ordinary stones." PCB is a promising industry in China, with double-digit growth rates every year. Many foreign ord
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