Analysis of the basic placement order of components on a printed circuit board
The usual order of placement of components on a printed circuit board: placing components in a fixed position that closely fits the structure, such as power outlets, indicators, switches, connectors, etc., after the device is placed, use the LOCK function of the software. Lock it so that it will not be mistakenly moved in the future; place special components on the line and large components such as heating elements, transformers, ICs, etc.; place small devices.
The distance of the component from the edge of the board: if possible, all components are placed within 3mm from the edge of the board or at least greater than the thickness of the board. This is due to the line slot in the mass production of the plug-in and wave soldering. In use, at the same time, in order to prevent the edge portion from being damaged due to the shape processing, if there are too many components on the printed circuit board, if it is necessary to exceed the 3mm range, a 3mm auxiliary edge can be added to the edge of the board, and the auxiliary side is opened V-shaped. The tank can be cut by hand during production.
Isolation between high and low voltage: There are high voltage circuits and low voltage circuits on many printed circuit boards. The components of the high voltage circuit are separated from the low voltage parts. The isolation distance is related to the withstand voltage. Usually, At 2000kV, the distance between the boards should be 2mm. On this basis, the ratio should be increased. For example, if you want to withstand the 3000V withstand voltage test, the distance between the high and low voltage lines should be more than 3.5mm. In many cases, to avoid Crawling, also slotting between high and low voltage on the printed circuit board.