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PCBA Tech
35 item standards of PCBA board inspection in SMT patch
PCBA Tech
35 item standards of PCBA board inspection in SMT patch

35 item standards of PCBA board inspection in SMT patch

2021-11-05
View:34
Author:Downs

The following is an introduction to the 35 project standards of PCBA board inspection in SMT patches:

01, SMT parts welding spot welding

02. Cold welding of the solder joints of SMT parts: use a toothpick to lightly touch the pins of the parts, if it can be moved, 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 overturning: the text face 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. SMT parts foot offset: the side offset is less than or equal to 1/2 of the width of the weldable end

12. SMT parts floating height: 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

pcb board

14. The heel of SMT parts is not flat against the heel and no tin is eaten

15. SMT parts cannot be recognized (printing is blurred)

16, SMT parts foot or body oxidation

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 height of the small solder joint is less than the thickness of the solder plus 25% of the height of the solderable end or the thickness of the solder plus 0.5mm, the smaller of which is (MA)

21, SMT parts eat too much tin: the height of the large solder joint exceeds the pad or climbs to the top of the solderable end of the metal plating end cap to allow acceptance, 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 one (including) or more 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, and the color of the PCB is different

31. PCB bending: the deformation of bending in any direction exceeds 1mm (300:1) per 300mm is (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)