SMT patch workshop PCBA board inspection project standard
01, SMT parts welding spot welding
02. Cold welding of the solder joints of SMT parts: use a toothpick to gently touch the pins of the parts, if you can pull it, it is cold welding
03, SMT parts (solder point) short circuit (tin bridge)
04, SMT parts are missing
05, SMT parts are wrong
06, SMT parts are reversed or wrongly polarized and cause burning or explosion
07, multiple SMT parts
08, SMT parts reversal: the text side is facing down
09, SMT parts stand side by side: chip element length ≤ 3mm, width ≤ 1.5mm, no more than five (MI)
10. Tombstone of SMT parts: the end of the chip component is lifted
11. Foot offset of SMT parts: side offset is less than or equal to 1/2 of the width of the weldable end
12. Floating height of SMT parts: the distance between the bottom of the component and the substrate
13. SMT parts foot high tilt: the height of the tilt is greater than the thickness of the part foot
14. The heel of SMT parts is not flat against the heel and no tin is eaten
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15. SMT parts can’t be identified (printing is illegible)
16. SMT parts feet or body are oxidized
17. SMT parts body damage: capacitor damage (MA); resistance damage is less than 1/4 of the component width or thickness (MI); IC damage in any direction
18. SMT parts use non-designated suppliers: according to BOM, ECN
19, SMT parts solder point tin tip: the height of the tin tip is greater than the height of the part body
20. SMT parts eat too little tin: the minimum solder joint height is less than the solder thickness plus 25% of the height of the solderable end or the solder thickness plus 0.5mm, the smaller of which is (MA)
21, SMT parts eat too much tin: the maximum solder joint height exceeds the pad or climbs to the top of the solderable end of the metal plating end cap is acceptable, and the solder contacts the component body (MA)
22. Tin ball/tin dross: more than 5 solder balls or solder splash (0.13mm or smaller) per 600mm2 is (MA)
23. The solder joints have pinholes/blow holes: one solder joint has more than one (inclusive) as (MI)
24. Crystallization phenomenon: there are white residues on the surface of the PCB board, solder terminals or around the terminals, and white crystals on the metal surface
25. The surface of the board is unclean: the uncleanness that cannot be found within 30 seconds of a long arm distance is accepted
26. Poor dispensing: the glue is located in the area to be welded, reducing the width of the end to be welded by more than 50%
27, PCB copper foil peeling
28. PCB exposed copper: the width of the circuit (gold finger) exposed copper is greater than 0.5mm for (MA)
29. PCB scratches: no substrate is seen from scratches
30. PCB burnt yellow: When the PCB is burnt and yellowed after the reflow oven or repaired, the color of the PCB is different from that of the PCB
31. PCB bending: the deformation of bending in any direction exceeds 1mm (300:1) per 300mm as (MA)
32. PCB inner layer separation (bubble): the area where blistering and delamination does not exceed 25% (MI) of the distance between plated holes or between inner wires; blistering between plated holes or between inner wires (MA)
33, PCB with foreign matter: conductive (MA); non-conductive (MI)
34, PCB version error: according to BOM, ECN
35. Gold finger dipping tin: the position of dipping tin falls within 80% of the edge of the board (MA)