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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
As a group of engineers, the sampling precautions include: 1. Carefully select the sample quantity to effectively control costs. 2. Special confirmation of device packaging to avoid sample failure due to packaging errors. 3. Conduct a global electrical inspection to improve the electrical performance of the PCB board. 4. Ensure signal integrity layout, reduce noise, and improve PCB stability. As a circuit board sampling manufacturer, the sampling precautions include: 1. Carefully check the PCB file information to avoid data issues. 2. Conduct global process approval and configure the process with our own manufacturers. 3. Control production quantity, reduce costs, and ensure quality. 4. Communicate precautions with sample customers to prevent accidents in advance.
The circuit board manufacturer reveals to you why the circuit board is deformed? The uneven copper surface area on the circuit board can worsen the bending and warping of the board. Nowadays, circuit boards are mostly multi-layer boards, and there are connection points (vias) between layers that are like rivets. The connection points are divided into through holes, blind holes, and buried holes. The places with connection points will limit the effect of board expansion and contraction, and indirectly cause board bending and warping. 1. Generally, circuit boards are designed with a large area of copper foil for grounding purposes. Sometimes, the Vcc layer also has a large area of copper foil. When these large areas of copper foil cannot be evenly distributed on the same circuit board, it will cause uneven heat absorption and dissipation speed. Of course, circuit boards will also expand and contract with heat. If the expansion and contraction cannot be achieved simultaneously, it wi
Circuit board sampling refers to the trial production of printed circuit boards before mass production. Generally, it refers to electronic products that are sent to PCB manufacturers for processing after being designed by engineers. The update and iteration of electronic products are relatively fast, so the demand for PCB sampling is gradually growing, and the market share is constantly expanding. With the increasing requirements for electronic product technology and information speed, the rise of multi-layer PCB sampling is relatively fast. 1. There are two ways to sample: formal PCB factories and specialized sample companies. It is more suitable to find a sampling company in your situation. They rely on sampling fees to survive and will definitely accept your request to only make two pieces. 2. The purpose of regular factory sampling is to have bulk orders, so of course, we hope to return orders; The sampling company itself only produces samples or small batches, and even if yo
1 Revenue Both high-frequency circuits and low-frequency power supply circuits have voltage gain and output power harvesting effects. Resonant differential amplification circuit refers to the resonant frequency f0, and for fiber broadband differential amplification circuit, it refers to a frequency range. 2-way band The concept difference with low-frequency power circuit boards is good. For resonant differential amplification circuits, most of them are the values between the two corresponding frequencies when the normalized vibration amplitude of the pointer decreases to 0.707 for the resonant frequency f0; For fiber optic broadband amplification circuits, it refers to the corresponding meaning relative to a certain frequency. 3. Selectivity Selectivity mainly targets resonant amplification circuits, which characterize the circuit's ability to select useful signals and suppress useless signals. Usually, the rectangular coefficient and suppression ratio are measured based on th
There are five main driving factors for the development of high-performance HDI circuit board products, which affect each other. The factors considered in this type of circuit design are: circuit components (signal integrity), sheet metal, stacking, and design standards. Although circuits are crucial for considering signal integrity, cost factors cannot be ignored. Based on this, it is important to consider a compromise solution during the operation process. The performance of the actual circuit varies with the rise time of the signal. These large area, high-performance HDI circuit boards handle high-speed computer buses or telecommunications signals, and are very sensitive to noise and signal reflection. The following five basic characteristics can describe signal sensitivity: characteristic impedance, low-voltage differential signal (LVDS), signal attenuation, noise sensitivity, and crosstalk interference. The characteristic impedance of single ended microstrip lines, stripline
If it is manual welding, it is necessary to develop good habits. Firstly, visually inspect the PCB board before welding, and use a multimeter to check whether key circuits (especially power and ground) are short circuited; Secondly, every time a chip is soldered, use a multimeter to measure whether there is a short circuit between the power supply and ground; In addition, do not throw the soldering iron indiscriminately during soldering. If the soldering tin is thrown onto the solder pins of the chip (especially surface mount components), it is not easy to detect. 2. Open the PCB diagram on the computer, light up the short circuit network, and see where it is closest to where it is most likely to be connected. Pay special attention to internal short circuits in the IC. 3. A short circuit was found. Take a board to cut the thread (especially suitable for single/double layer boards), and after cutting the thread, power on each part of the functional block separately, and exclude som
1. Static design Static design refers to the bending or folding that a product only encounters during the assembly process, or the bending or folding that rarely occurs during use. Single sided, double-sided, and multi-layer circuit boards can all successfully achieve folded static design. Usually, for most double-sided and multi substrate designs, the bending radius of the fold should be ten times the thickness of the entire circuit. Circuits with more layers (eight or more) will become very hard and difficult to bend, so there will be no problems. Therefore, for double-sided circuits that require strict bending radius, all copper wires should be set on the same side of the substrate film in the folding area. By removing the film covering on the opposite side, the folded area is approximated as a single sided circuit. 2. Dynamic design The design of dynamic circuits is aimed at the repeated bending that occurs throughout the entire lifecycle of the product, such as the cables o
Reduce weight and space Compared to other solutions, flexible printed circuit boards not only provide greater design freedom, but also better space utilization and weight efficiency. Flexible printed circuit boards are thin and lightweight, which can greatly reduce weight and space. For smaller devices, these flexible plates can be folded, creased, and placed in smaller areas to miniaturize the device. This makes flexible circuit boards more suitable for small devices, as they can be installed in areas where rigid circuit boards cannot be installed. flexibility The main advantages of flexible circuit boards are their elasticity and bending ability. Therefore, they can be manipulated in various ways to fit edges, folds, and creases. The flexibility of the circuit board also means that it is more reliable and durable than ordinary PCBs, as it can reduce the impact of vibration and has very few wiring on the circuit board. Minimal wiring eliminates the need for interface connection
For a PCB sample, please prepare the following information in advance to inquire about it. Being straightforward and not talking nonsense can save you valuable time. More importantly, we are also experts in preparation, and pricing is not at a loss. The PCB circuit board manufacturer has summarized the following points and hopes to help you. Material: What kind of material is required for the design of PCB circuit boards? Currently, FR4 is commonly used, and the commonly used material is epoxy resin peeled fiber cloth board. Board layer: The number of layers for designing PCB circuit boards (the design layers for PCB sampling may vary in price, and the PCB sampling process is similar) Solder resistance color: There are many colors available, which can be selected according to the company's needs, with the commonly used color being green. Screen printing color: The font and border color for screen printing on PCB circuit boards, often selected as white. Copper thickness: Scient
How to check for short circuits on a PCB circuit board? PCB circuit board manufacturers teach you six simple troubleshooting methods. Firstly, computers can easily connect to PCBs, opening up PCB designs, illuminating short-circuit networks, and observing closer areas. Special design should pay attention to internal short circuits in the IC. If it is manual welding, please develop good habits: Before welding, visually inspect the PCB board and use a multimeter to check for short circuits in key circuits (especially power and ground); Welding of finished products for measuring power and ground short circuits using a multimeter to various chips; Do not throw soldering iron randomly during welding. If solder is thrown onto the solder feet of the chip (especially for surface mounted components), it will be difficult to find it. Analyze the main instruments using a short circuit positioning system If there is a BGA processing chip, as all tin points are covered by the processing
Can be high-density For many years, the high-density of printed boards has been able to develop correspondingly with the improvement of integrated circuit integration and the advancement of installation technology. high reliability Through a series of inspection, testing, and aging tests, it is possible to ensure that PCBs can work reliably for a long time (usually with a lifespan of 20 years). Designability The requirements for various properties of PCBs (electrical, physical, chemical, mechanical, etc.) can be achieved through design standardization and standardization. This design has a short time and high efficiency. Producibility PCB adopts modern management, which can achieve standardization, scale (quantity), and automated production, thereby ensuring the consistency of product quality. [2] Testability We have established relatively complete testing methods and standards, which can be used to detect and evaluate the qualification and service life of PCB products thr
1. Spacing between wires For the processing capacity of Shenzhen PCB manufacturers, the minimum distance between wires should not be less than 3mil. The minimum line distance is also the distance from line to line and from line to pad. From a production perspective, if conditions permit, the larger the better, with a common one being 10mil. 2. Pad aperture and pad width In terms of the processing capacity of PCB manufacturers in Shenzhen, if the pad aperture is mechanically drilled, the minimum should not be less than 0.15mm, and if laser drilling is used, the minimum should not be less than 4mil. The aperture tolerance varies slightly depending on the plate, and can generally be controlled within 0.05mm. The minimum width of the welding pad should not be less than 0.2mm. If copper is laid on a large area, there usually needs to be an internal shrinkage distance of 20mil from the edge of the board. In the PCB design and manufacturing industry, in general, due to mechanical cons
Firstly, a PCB or GERBER file needs to be provided, which should include plate making instructions - including specific requirements such as board layers, materials, solder pad process, ink color, etc. Below, we will provide a detailed explanation of some of the main parameters. Material: It is necessary to explain what kind of material is required for PCB production. Currently, the most common method is to use FR4, which is mainly made of epoxy resin peeled fiber cloth board. Board layer: It is necessary to specify the number of layers for making PCB boards. (The production layers of PCB boards vary, and the price will also vary. The sampling process for PCB circuit boards is very similar.) Solder resistance color: There are many colors available, which can also be selected according to requirements, usually green. Screen printing color: The font and border color for screen printing on a PCB are generally selected as white. Copper thickness: Generally, the scientific calculat
As the name suggests, a multi-layer circuit board can only be called a multi-layer circuit board if it has two or more layers. Previously, we analyzed what a double-sided circuit board is, so a multi-layer board is more than two layers, such as four layers, six layers, eight layers, and so on. Of course, some designs are three or five layer circuits, also known as multi-layer PCB circuit boards. A conductive wiring diagram larger than a two-layer board, with insulating substrates separating the layers. After each layer of wiring is printed, it is then pressed together to overlap each layer of wiring. Afterwards, drilling will be carried out to achieve continuity between each layer of the line through holes. The advantage of multi-layer PCB circuit boards is that the circuits can be distributed and wired within multiple layers, allowing for the design of more precise products. Or smaller products can be achieved through multi-layer boards. Products with larger volumes such as mobile
Both sides of the PCB board are copper layers, and PCB boards without resistance welding are prone to oxidation when exposed in the air, resulting in poor product quality and affecting the electrical performance of the PCB board. Therefore, there must be a protective coating on the surface of PCB circuit boards that can block the oxidation reaction between PCB and air, and this coating is a solder mask layer covered with solder mask material. Various colors of solder resist paint have also emerged, forming colorful PCB circuit boards, and solder resist colors have no relationship with the quality and electrical performance of PCB boards. The surface of the PCB board also needs to be soldered with electronic components, so a portion of the copper layer needs to be exposed for easy soldering of components, which is the solder pad. As mentioned earlier, the exposed copper layer is prone to oxidation reaction, so the solder pad also needs to have a protective layer to prevent oxidatio
Millimeter wave radar sensors are transitioning layer by layer from 24GHz to 77GHz, and more forward facing and angle radars are considering it appropriate to use the 77GHz scheme. For circuit engineers, selecting the appropriate PCB material is crucial for preset millimeter wave radar. In general, when selecting, it is necessary to consider the selection of thinner PCB circuit board materials, better dielectric constant uniformity, and smaller media damage; At the same time, it is also important to consider the reliable electrical performance and mechanical properties of materials that have reliable external office backgrounds such as time, temperature, and humidity. 8-layer second-order HDI mobile phone board In the preset array receiving antenna of millimeter wave radar, the circuit structure dimensions of different types of channel transmission lines, the phase difference or delay of different channel transmission lines, and the successful implementation of spacing control be
The component library requirements for PCBs are high, which directly affects the installation of the board; SCH's component library requirements are relatively loose, as long as you pay attention to defining pin attributes and corresponding relationships with PCB components. PS: Note the hidden pins in the standard library. After that, the schematic design will be completed, and once it is ready, we will start working on PCB design. Secondly, PCB structure design. In this step, based on the determined circuit board size and various mechanical positioning, draw the PCB board surface in the PCB design environment, and place the required connectors, buttons/switches, screw holes, assembly holes, etc. according to the positioning requirements. And fully consider and determine the wiring area and non wiring area (such as the extent of non wiring area around screw holes). Third: PCB layout. Simply put, layout means placing devices on a board. If all the preparations mentioned earlier are
What is a differential distribution line: A differential distribution line mainly distinguishes the traditional signal transmission method where a signal line corresponds to a ground wire. Differential signal transmission mainly involves signal transmission on both lines, with equal amplitudes and opposite phases of the two signals. Compared to traditional single ended signals, it has advantages such as strong anti-interference, effective suppression of electromagnetic interference, and timing positioning preparation. How to arrange differential lines? When designing circuit boards, two points should be noted for the wiring of differential pairs: Firstly, the length of the two lines should be as long as possible; The other is that the distance between the two lines (determined by the differential impedance) should remain constant, that is, parallel. There are usually two parallel ways, one is for two lines on the PCB board to run on the same side by side layer, and the other
The dielectric constant of a PCB is generally between 4.2 and 4.7 relative to air at room temperature, but this value usually varies with temperature. Generally, its maximum variation can reach 20% in the temperature range of 0 to 70 degrees. The change in dielectric constant will lead to a change in line delay of about 10%, and the higher the temperature, the greater the delay. And it will also change with frequency, the higher the frequency, the smaller the dielectric constant. Different media thicknesses and their different combinations Serial number Theoretical thickness (MM) Theoretical thickness (MIL) Combination method Dielectric constant 1 0.05 1.97 106 * 1 3.9 2 0.07 2.76 1081 * 1 4.2 3 0.08 3.2 LPP1080 * 1 4.2 4 0.1 4 106 * 2 3.9
1) IPC-7525: Template Design Guidelines. Guidelines were provided for the design and manufacturing of solder paste and surface mount adhesive coated templates. Template design using surface mount technology was also discussed, and templates with through-holes or flip chip components were introduced? Kunhe technology, including overprinting, double printing, and stage template design. 2) IPC-Ca-821: General requirements for thermal adhesives. This includes the requirements and testing methods for thermal conductive dielectrics that are used to bond components to suitable locations. 3) IPC-M-I08: Cleaning Instruction Manual. Includes the latest version of IPC cleaning guidance to assist manufacturing engineers in determining the cleaning process and troubleshooting of products. IPC-CH-65-A: Cleaning Guidelines for Printed Circuit Board Assembly Question # e# 4) IPC-7095: Supplement to the design and assembly process of SGA devices. Provide various useful operational information fo
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