Circuit Board Inspection Defect Definition Description

1, PT surface: welding surface 2, MT surface: parts assembly surface;

3. Light defects: due to its poor quality, it may reduce the performance of printed circuit board and shorten its life;

4. Minor defects: poor quality will reduce the commodity value, but it will not affect the performance and life of printed circuit board;

5. Conical hole: Because the gap between the upper hole and the lower hole of the stamping model is too large, the hole section shape of the punched parts and other parts is the horn shape that opens to the assembly side of the parts;

6. Serious defect: printed circuit board cannot be used for the purpose due to its poor quality;

7. Conical hole: Because the gap between the upper hole and the lower hole of the stamping model is too large, the hole section shape of the punched parts, etc., is a horn shape that opens to the assembly side of the parts.

In PCB manufacturing process, film, exposure, development, are particularly prone to problems, we need to pay attention to.

Dry film bottom garbage -- it is not caused by sticking dust to the board surface before sticking the film. When the garbage is large, part of it will be covered by dry film after developing, which will lead to residual copper/short circuit, etc.;

Exposure of garbage -- due to unclean exposure, dry film cannot be sufficiently exposed due to garbage blocking, which will lead to open path/gap/pinhole, etc.

Development -- Development maintenance is not in place, there is a dry film residue on the roller, will stick to the plate surface, resulting in etching copper residue;