When we get a PCB board, if there are no other test tools, how to quickly judge the quality of the PCB board?
1. The size and thickness of the PCB board must be consistent with the specified appearance size and thickness, and there must be no deviation. The surface of the circuit board is free of defects, deformation, shedding, scratches, open circuits, short circuits, oxidized white, yellow, dirty or excessively etched, free of dirt, copper particles and other impurities.
2. The ink covering layer is uniform, bright, without falling off, scratches, copper dew, deviation, printing plate, etc.
3. The symbols and letters in the screen printing are clear, without omissions, ambiguities, reversals, deviations and other undesirable phenomena.
4. The carbon film must not have defects, deviations, short circuits, open circuits, reverse printing, etc.
5. PCB bottom plate molding, no leakage, deviation, hole collapse, piercing, plug hole, beer burst, beer reverse, crushing and other phenomena.
6. Whether the edge of the PCB is smooth, if it is a V-shaped cutting process, you should pay attention to whether the V-shaped cutting groove causes breakage, whether the two sides are symmetrical, etc.
Usually through these 6 points, you can quickly judge the quality of the PCB board.
1. The copper surface is not easy to oxidize, which affects the installation speed, and it will be broken soon after being oxidized;
2. The components are required to be easy to use after installation, that is, the electrical connection must meet the requirements;
3. The copper skin is not easy to fall off under high temperature;
4. The line width, line thickness, and line distance of the line meet the requirements to prevent the line from heating, breaking, and short-circuiting;
5. No additional electromagnetic radiation;
6. High temperature, high humidity and special environment resistance should also be considered;
7. The shape is not deformed, so as to avoid deformation of the shell and dislocation of screw holes after installation. Now they are all mechanized installations, the hole position of the circuit board and the deformation error of the circuit and design should be within the allowable range;
8. The mechanical properties of the surface must meet the installation requirements;