As a new member of the switching power supply family, LED switching power supply has been widely used in many fields. In the process of new product development, the component layout of PCB is an important part of the design of LED switching power supply, and it is also one of the key tests of the engineer's design scheme. So, what should we do to make the layout of PCB components achieve the best results?
The first thing you need to do is to fully consider the size of the PCB. When the PCB size in the switching power supply is too large, because the printed line is too long, it will lead to an increase in impedance, a decrease in anti-noise ability, and a corresponding increase in cost. Once the printed circuit board is too small, the heat dissipation is not good, and the adjacent lines are susceptible to interference. Generally speaking, the best shape of the PCB circuit board for LED switching power supply is rectangular, the aspect ratio is 3:2 or 4:3, and the components located on the edge of the circuit board are generally not less than 2mm from the edge of the circuit board.
Secondly, after completing the design of the PCB size, we also need to consider the distribution parameters between components, which is especially important for circuits that work under high frequency conditions. The general circuit should make the components parallel as far as possible, so that it is not only beautiful, but also easy to install and weld, and easy to mass production.
Then, when placing the components of the PCB board, do not blindly seek speed, at this time, it is necessary to consider the future welding problems. This also requires engineers to carry out reasonable component layout, do not put too dense between components. In the design process, engineers should focus on the core components of each functional circuit, and carry out the overall component layout around the core components. In the layout process, the components should be evenly, neatly and compact arranged on the PCB, minimize and shorten the leads and connections between the components, and the decoupling capacitor should be as close as possible to the VCC of the device.
Finally, when carrying out the PCB component layout of the LED switching power supply, it is recommended that engineers arrange the position of each functional circuit unit according to the circuit process, such a layout can make the signal flow more effective and fast, and keep the signal in the same direction as possible. When carrying out the layout of the PCB board, the first principle is to ensure the distribution flux of the wiring, pay attention to the connection of the flying line when moving the device, and put the connected devices together. The loop area is reduced as much as possible to suppress the radiation interference of the switching power supply.
As long as the above points are done, the LED switching power supply will have the best PCB component layout.
SMT chip processing technology will become more and more popular
The degree of automation of electronic equipment is a sign of whether a country is a power in electronic manufacturing. Domestic electronic SMT(Surface Mount Technology) manufacturing equipment in the printing press, reflow welding, AOI(automatic optical inspection) equipment and other links have made great progress, and in the SMT SMT processing of the most critical SMT machine (except for small SMT machine) is still not a company can produce, still by Japan, Germany, South Korea, the United States held, Faced with severe capital, technology, standards and many other problems. To realize the dream of electronic manufacturing power, we must take the road of independent research and development of SMT equipment, and concentrate our superior strength to break through the industrialization dilemma of the SMT machine.
Surfacd Mounting technology (SMT) is a new generation of electronic assembly technology, which compresses traditional electronic components into only tens of the volume of the device, so as to achieve high density, high reliability, miniaturization, low cost, and production automation of electronic product assembly. This miniaturized component is called: SMY device (or SMC, chip device). The process of assembling components onto a printed or other substrate is called the SMT process. The associated assembly equipment is called SMT equipment.
SMT production line mainly includes: SMT machine, printing machine, SPI(solder paste detector), wave soldering equipment, reflow welding equipment, AOI testing equipment, X-Ray testing equipment, repair workstation, etc. The technologies involved include: mounting, welding, semiconductor packaging, assembly equipment design, circuit forming process, function design simulation technology, etc. At present, more than 80% of the electronic products in developed countries such as Japan and the United States use SMT. Among them, network communications, computers and consumer electronics are the main application areas, accounting for about 35%, 28% and 28% of the market respectively.
Among them, the SMT machine is used to achieve high-speed, high-precision, automatic placement of components equipment, related to the efficiency and accuracy of the SMT production line, is the most critical and complex equipment, accounting for more than 60% of the entire SMT production line investment. At present, the placement machine has developed into a high-speed optical alignment placement machine, and has developed to multi-function, flexible and modular. Domestic enterprises in printing, welding, testing and other links have emerged more powerful enterprises, such as Nitto welding equipment, and printing equipment, Shenzhou Vision AOI testing equipment, X-Ray testing equipment and so on. At present, reducing labor costs and enhancing the level of automation are the fundamental requirements for the transformation and upgrading of manufacturing technology, and have also brought strong demand for SMT equipment. High performance, ease of use, flexibility and environmental protection are one of the main trends of SMT equipment.
At present, advanced electronic products, especially in computers and communication electronic products, have widely adopted SMT technology. The international output of SMT devices is increasing year by year, while the output of traditional devices is decreasing year by year, so with the passage of time, SMT chip processing technology will become more and more popular.