What items and inspection standards need to be inspected for PCBA boards?
Mar 02, 2023
1. What is the PCBA board inspection standard?
Let us first understand the introduction of the standard shortcomings of quality inspection
1. Serious shortcomings (expressed in CR): Any shortcomings that are sufficient to cause injury to human body or machine or endanger life safety such as: non-compliance with safety regulations/burning-in/touching
electricity etc.
2. Main defect (indicated by MA): the defect that may cause product damage, abnormal function or affect the service life of the product due to the material.
3. Minor shortcomings (indicated by MI): do not affect product function and service life, some defects in appearance and slight differences in mechanism assembly
What items and inspection standards need to be inspected for PCBA boards
2. Inspection conditions of PCBA board:
1. In order to prevent contamination of components or components, gloves or finger cots with full EOS/ESD protection functions must be selected and electrostatic rings must be worn for operations, light sources
It is a white fluorescent lamp, the light intensity must be above 100Lux, and it can be clearly seen within 10 seconds.
2. Inspection method: place the product to be inspected at a distance of about 40cm from the eyes, at a distance of 45° from top to bottom, left, and right, and inspect it visually or with a three-fold magnifying glass.
3. Inspection and judgment standard: (Sampling shall be carried out according to the sampling level of QS9000 C=0 AQL=0.4%; if the customer has special requirements, the bid shall be accepted by the customer
quasi-judgment)
4. Sampling plan: MIL-STD-105E LEVEL Ⅱ normal type single sampling
5. Judgment criteria: serious defect (CR) AQL 0%
6. Major Disadvantage (MA) AQL 0.4%
7. Minor defect (MI) AQL 0.65%
3. SMT patch workshop PCBA board inspection item standard
01. Empty welding of solder joints of SMT parts
02. Cold soldering of solder joints of SMT parts: Use a toothpick to lightly move the pins of the parts, if they can be moved, it is cold welding
03, SMT parts (solder joints) short circuit (tin bridge)
04, SMT parts missing
05. Wrong SMT parts
06. The polarity of SMT parts is reversed or wrong, causing combustion or explosion
07, Multiple SMT parts
08, SMT part flip: text face down
09, SMT parts stand sideways: chip components 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: the 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 is <1mm
13. SMT part feet are high and warped: the height of the warping is greater than the thickness of the parts feet
14. The heel of SMT parts is not flat and the heel is not tinned
15. SMT parts cannot be identified (printing is blurred)
16. Oxidation of feet or body of SMT parts
17. SMT part body damage: capacitor damage (MA); resistance damage is less than 1/4 (MI) of the component width or thickness; IC damage is long in any direction
Degree <1.5mm (MI), exposed internal material (MA)
18. SMT parts use non-designated suppliers: according to BOM, ECN
19. Tin tip of solder joints of SMT parts: 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 25% of the solder thickness plus 25% of the solderable end height or the solder thickness plus 0.5mm, whichever is smaller
or (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-plated end cap, which is acceptable, and the solder contact
Component body (MA)
22. Solder balls/solder slag: more than 5 solder balls or solder splashes (0.13mm or less) per 600mm2 (MA)
23. There are pinholes/blowing holes in the solder joints: one solder joint (including) or more is (MI)
24. Crystallization phenomenon: on the surface of the PCB board, there are white residues around the soldering terminals or terminals, and there are white crystals on the metal surface
25. Dirty board surface: Uncleanness that cannot be found within 30 seconds of long-distance arm is acceptable
26. Bad 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 warping
28. PCB exposed copper: the line (gold finger) exposed copper width is greater than 0.5mm (MA)
29. PCB scratches: scratches without seeing the substrate
30. PCB burnt yellow: When the PCB is burned and yellowed after reflow oven or maintenance, it is different from the color of the PCB
31. PCB bending: the deformation of bending in any direction exceeds 1mm (300:1) for every 300mm (MA)
32. PCB inner layer separation (bubble): The area where blistering and delamination occurs does not exceed 25% (MI) of the distance between plated holes or internal wires;
Blistering between covered holes or internal wires (MA)
33. PCB with foreign matter: conductive (MA); non-conductive (MI)
34. PCB version error: according to BOM, ECN
35. Gold finger tin dipping: the tin dipping position falls within 80% of the edge of the board (MA)
4. PCBA board inspection item standard in DIP post-welding workshop
01. Empty welding of solder joints of DIP parts
02. Cold welding of solder joints of DIP parts: Use a toothpick to lightly move the pins of the parts, if they can be moved, it is cold welding
03, DIP parts (solder joints) short circuit (tin bridge)
04. Missing DIP parts:
05, DIP part wire length: Φ≤0.8mm→wire length is less than or equal to 1.5mmΦ＞0.8mm→wire length is less than or equal to 2.0mm special cut
foot requirement excluded
06. Wrong DIP parts:
07. The polarity of DIP parts is reversed or wrong, causing combustion or explosion
08. Deformation of the feet of DIP parts: the bending of the pin exceeds 50% of the thickness of the pin
09. Floating height or high warping of DIP parts: Refer to IPC-A-610E, depending on special circumstances according to assembly
10. Tin tip of solder joints of DIP parts: The height of tin tip is greater than 1.5mm
11. Unrecognizable DIP parts: (printing blurred)
12. Oxidation of feet or body of DIP parts
13. The body of the DIP part is damaged: the surface of the component is damaged, but the metal material inside the component is not exposed
14. DIP parts use non-designated suppliers: according to BOM, ECN
15. Vertical filling and peripheral wetting of PTH holes: minimum 75% vertical filling, at least 270º wetting of pins and hole walls
16. Solder balls/solder dross: more than 5 solder balls or solder splashes (0.13mm or less) per 600mm2 (MA)
17. There are pinholes/blowing holes in solder joints: three (including) or more solder joints are (MI)
18. Crystallization phenomenon: On the surface of the PCB board, there are white residues around the soldering terminals or terminals, and there are white crystals on the metal surface
19. Dirty board surface: Uncleanness that cannot be found within 30 seconds of long-distance arm is acceptable
20. Poor glue dispensing: The glue is located in the area to be welded, reducing the width of the end to be welded by more than 50%
21. PCB copper foil warping:
22. PCB exposed copper: the line (gold finger) exposed copper width is greater than 0.5mm (MA)
23. PCB scratches: scratches without seeing the substrate
24. PCB burnt yellow: When the PCB is burned and yellowed after reflow oven or maintenance, it is different from the color of the PCB
25. PCB bending: the deformation of bending in any direction exceeds 1mm (300:1) for every 300mm (MA)
26. PCB inner layer separation (bubble): The area where blistering and delamination occurs does not exceed 25% (MI) of the distance between plated holes or internal wires;
Blistering between covered holes or internal wires (MA)
27. PCB with foreign matter: conductive (MA); non-conductive (MI)
28. PCB version error: according to BOM, ECN
29. Gold finger tin dipping: The position of tin dipping falls within 80% of the edge of the board (MA)