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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 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
Both sides of a PCB circuit board and above will require copper to be sunk into the holes, making the holes have copper and become electrical holes. However, during the production process, the manufacturer may occasionally discover that there is no copper or copper is unsaturated in the hole after copper deposition. Now, our company briefly describes several reasons. The reason for the absence of copper in the pores is nothing more than: 1. Drill dust plug holes or holes with coarse diameter. 2. When depositing copper, there are bubbles in the solution and no copper is deposited in the hole 3. There is circuit ink inside the hole, no protective layer is applied, and there is no copper in the hole after etching. 4. If the acid and alkali solution in the hole is not cleaned thoroughly after copper deposition or plate electrification, and the parking time is too long, slow bite corrosion will occur. 5. Improper operation and prolonged residence time during micro etching process.
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