Electronic Design - Analysis on the three main points of PCB circuit board design

Surface Mounted Technology (SMT) is the most popular Technology and process in electronic assembly industry.

SMT is a circuit assembly technology in which a pin less or short lead surface assembly component (SMC/SMD for short, chip component in Chinese) is mounted on the surface of a PCB or other substrate, and then welded and assembled by reflow welding or dip welding.

Why use SMT?

1, the pursuit of miniaturization of electronic products, before the use of perforation plug-in components have been unable to shrink, electronic product function is more complete, integrated circuit (IC) has been adopted by the element without perforation, large-scale, high integrated IC, in particular, to adopt the surface patch element mass, product production automation, the manufacturer to high production with low cost, To produce quality products to meet customer needs and strengthen market competitiveness.

2, the development of electronic components, the development of integrated circuit (IC), the multiple applications of semiconductor materials, the revolution of electronic science and technology is imperative, chasing the international trend.

Technical characteristics of SMT:

1, high assembly density, small size and light weight of electronic products, the volume and weight of SMT components only about 1/10 of the traditional plug-in components, generally using SMT, electronic products shrink 40%~60%, 60%~80% weight.

2, high reliability, strong vibration resistance. Solder joint defect rate is low.

3, high frequency characteristics. Reduced electromagnetic and radio frequency interference.

4, easy to realize automation, improve production efficiency. Reduce cost by 30%~50%. Save materials, energy, equipment, manpower, time, etc.

For PCB design novices, there are some design points that need special attention. If you don't pay attention, then the designed PCB will probably not be put into use. Today, Jinbei Ke will explain to you the three must-know points in PCB circuit board design.

First, it is equal length. When designing the differential line, pay attention to making the two signal lines the same length. Because the length of the signal line is the same, the transmission time of the signal is also the same, so the polarity of the differential signal will be different, resulting in the opposite situation. If the differential signals are the same, the signal quality will be poor.

Next, it is equidistant. In other words, the distance between the pairs of differential lines must be consistent. By adjusting the distance of the differential line, we can adjust a differential impedance throughout the process. What is the advantage of doing so? If our differential impedance can maintain a certain continuity, then there will be very little reflection and the transmitted signal is also very complete. .

The second is the stacking of differential lines and printed boards. It is generally believed that the differential line will provide a reflow path for the printed board, and the printed board will use this method to reflow through the differential line, so pay attention to stacking the differential line and the printed board during the design.

When designing a PCB circuit board, only by memorizing the above three points can the probability of error be greatly reduced, and the design quality and use value of the PCB circuit board can be continuously improved, so as to truly output high-quality products for customers.

ipcb is a domestic dedicated circuit board manufacturer, dedicated to the R&D, production and sales of 2-60 layer high-precision, special circuit boards, and specializes in serving high-tech enterprises and scientific research units at home and abroad. Products cover power supply, medical equipment, industrial control, communications, automotive electronics, security electronics, LED lighting and display screens, consumer electronics and other fields. The products are exported to Europe, America and other countries.