Requirements for board design
This is the most basic and important requirement of PCB design, which can accurately realize the connection relation of electrical schematic diagram and avoid the two simple and fatal mistakes of "short circuit" and "break circuit".This basic requirement is not easy to be achieved in the manual design and PCB designed with simple CAD software. The general products have to undergo more than two rounds of trial production and modification, while the powerful CAD software has the inspection function, which can guarantee the correctness of electrical connection.
This is a higher level of demand in PCB design.Properly connected circuit boards are not always reliable, for example, unreasonable selection of boards, incorrect board thickness and mounting fixation, improper component layout and wiring, etc., all of which may lead to the failure of PCB to work reliably, and the early failure may even fail to work correctly at all.It is much easier to design with multiple layers than with single or double panels, but less reliable than single or double panels.From the perspective of reliability, the simpler the structure, the smaller the application surface, the smaller the number of sub-layers, the higher the reliability.
This is a deeper and more difficult requirement in PCB design.A PCB components, from PCB fabrication, inspection, assembly, debugging to whole machine assembly and debugging, until the use of maintenance, all without exception is reasonable or not is closely related with the printed circuit board, such as the board shape well processing difficulties, pin hole is too small assembly difficulty, was left pilot highly difficult, outside the plate connected to incorrect maintenance difficulties, and so on.Each difficulty can lead to increased costs and longer working hours.And each cause of the difficulty stems from the designer's error.There is no absolutely rational design, only a process of continuous rationalization.It needs the designer's sense of responsibility and rigorous style, as well as the experience of summary and improvement in practice.
This is not difficult to achieve, not easy to achieve, but must be achieved.Say "not difficult", board choose low price, board dimension as far as possible small, connect with direct welding lead, surface is coated with the cheapest, the processing plant that chooses lowest price is waited a moment, printing plate makes a price to be able to drop.But do not forget, these cheap choice may cause craft sex, reliability to become poorer, make manufacturing cost, maintain charge to rise, overall economy does not need to divide a place, say so "not easy"."Must" is the principle of market competition.Competition is relentless, a principle advanced, technologically advanced product may die on economic grounds.