As ordinary laymen sometimes emphasize the former more, in order to assess the merits of the circuit design in a one-sided manner, in order to image the product, priority should be given to the former when the performance requirements are not harsh. However, in the case of high performance, if you have to use a double panel, and it is also packaged inside, and you can't see it normally, you should give priority to the aesthetics of the cable.
Second, the force circuit board should be able to withstand various external forces and vibrations during installation and work.
To this end, the circuit board should have a reasonable shape, and the positions of various holes (screw holes, shaped holes) on the board should be reasonably arranged. Generally, the distance between the hole and the edge of the plate is at least larger than the diameter of the hole. At the same time, it should be noted that the weakest section of the plate caused by the profiled hole should also have sufficient bending strength. The connectors on the board that “stretch” directly out of the device housing must be reasonably fixed to ensure long-term reliability.
Third, heat For high-power, serious heat devices, in addition to ensuring the heat conditions, but also pay attention to place in the appropriate location.
Especially in sophisticated analog systems, special attention must be paid to the adverse effects of the temperature field generated by these devices on the fragile preamplifier circuit. The very large part of the general power should be made into a single module, and take some thermal isolation measures with the signal processing circuit.
Fourth, the signal; signal interference is the most important factor to consider in PCB layout design.
The most basic aspects are: weak signal circuit and strong signal circuit are separated or even isolated; the AC part is separated from the DC part; the high frequency part is separated from the low frequency part; attention is paid to the direction of the signal line; the arrangement of the ground line; proper shielding and filtering And other measures. These are a large number of articles that have been repeatedly emphasized and will not be repeated here.
V. A series of basic requirements.
Installation means that in order to install the circuit board smoothly into the chassis, casing, and slot under specific application occasions, there will be no space interference, short-circuit accidents, etc., and the specified connector will be placed at a designated position on the chassis or housing.