Drawing PCB board experience

Printed board design requirements:

Correct: This is the most basic and important requirement for printed circuit board design. It accurately realizes the connection relationship of the electrical schematic diagram and avoids two simple and fatal errors such as “short circuit” and “open circuit”. This basic requirement is not easy to do in manual design and PCB design with simple CAD software. The general product has to be modified by two or more trials. The more powerful CAD software has the inspection function to ensure the electrical connection. Correctness.

Reliable: This is a higher level requirement in PCB design. Connecting the correct circuit board is not necessarily reliable. For example, the board selection is unreasonable, the board thickness and installation are not fixed correctly, and the improper layout and wiring of the components may cause the PCB to work reliably. It may not work properly at the early stage. Another example is that the multi-layer board is much easier to design than the single and double panels, but it is not as reliable as the single or double panel. From the perspective of reliability, the simpler the structure, the smaller the surface to be used, and the fewer the number of layers of the board, the higher the reliability.

Reasonable: This is a deeper and less difficult requirement in PCB design. A printed board assembly, from the manufacture, inspection, assembly, commissioning of the printed board to the assembly and commissioning of the whole machine, to the use and maintenance, is closely related to the rationality of the printed board. For example, the shape of the board is not easy to process. The lead hole is too small to assemble, and it is difficult to maintain the pilot. The improper connection of the board is difficult to maintain and so on. Every difficulty can lead to increased costs and extended working hours. And every cause of the difficulty stems from the designer's mistakes. There is no absolutely reasonable design, only the process of continuous rationalization. It requires the designer's sense of responsibility and rigorous style, as well as the experience of summarizing and improving in practice.

Economy: This is a goal that is not difficult to achieve and is not easy to achieve, but must be achieved. It is not difficult to say that the board is low-priced, the board size is as small as possible, the straight-welded wire is connected, the surface is coated with the cheapest, and the lowest-priced processing plant is selected, and the manufacturing price of the printed board will drop. But don't forget that these cheap choices may cause craftsmanship, poor reliability, increase manufacturing costs, maintenance costs, and overall economics are not necessarily separate, so it is "not easy." “Must” is the principle of market competition. Competition is ruthless, an advanced technology, high-tech products may die for economic reasons.