1. What Are the Inspection Standards for PCBA Boards? First, let us understand the introduction of quality inspection standards. 1. Serious defects (denoted as CR): Any defect that can cause harm to a person or machine or endanger life safety, such as non-compliance with safety regulations, burning machines, electric shock, etc. 2. Major defects (denoted as MA): Defects that may cause product damage, functional abnormalities, or affect the product’s lifespan due to materials. 3. Minor defects (denoted as MI): Defects that do not affect product functionality and lifespan, such as minor cosmetic flaws or slight assembly discrepancies.
What items and standards should PCBA boards be inspected for?
2. Inspection Conditions for PCBA Boards: 1. To prevent contamination of components or assemblies, gloves or finger cots with full EOS/ESD protection must be selected, and a static ring must be worn during operations. The light source should be white daylight lamps, with light intensity above 100 Lux, clearly visible within 10 seconds. 2. Inspection method: Place the item to be inspected about 40 cm from the eyes, checking visually or with a threefold magnifying glass at angles of 45º up and down, left and right. 3. Inspection determination standards: (Sampling based on QS9000 C=0 AQL=0.4%; if the client has special requirements, judgment will depend on the client’s acceptance standards.) 4. Sampling plan: MIL-STD-105E LEVEL II normal single sampling. 5. Determination standards: Serious defects (CR) AQL 0%. 6. Major defects (MA) AQL 0.4%. 7. Minor defects (MI) AQL 0.65%.
Inspection Standards for PCBA Boards in the SMT Assembly Workshop
3. Inspection Standards for PCBA Boards in the SMT Assembly Workshop 01. SMT component solder joint cold soldering: Use a toothpick to lightly poke the component pins; if they can be moved, it is cold soldering. 02. SMT component (solder joint) short circuit (solder bridge). 03. Missing SMT components. 04. Incorrect SMT components. 05. SMT component polarity reversed or incorrect, causing burning or explosion. 06. Multiple SMT components. 07. SMT components upside down: text side down. 08. SMT components standing on the side: for chip components, length ≤ 3mm, width ≤ 1.5mm, no more than five (MI). 09. SMT components tombstone: ends of chip components lifted. 10. SMT component leg offset: side offset less than or equal to half the width of the solderable end. 11. SMT components floating high: distance between the component bottom and the substrate < 1mm. 12. SMT component legs lifted: height greater than the thickness of the component legs. 13. SMT component legs not flat: legs not soldered. 14. SMT components not identifiable (printing unclear). 15. SMT component legs or bodies oxidized. 16. SMT component body damaged: capacitor damaged (MA); resistor damaged less than 1/4 of the component width or thickness (MI); IC damaged in any direction length < 1.5mm (MI), exposing internal materials (MA). 17. SMT components using non-designated suppliers: according to BOM, ECN. 18. SMT component solder joint solder spikes: spike height greater than the component body height. 19. SMT components with insufficient solder: minimum solder joint height less than 25% of solder thickness plus solderable end height or less than solder thickness plus 0.5mm, the smaller of the two (MA). 20. SMT components with excessive solder: maximum solder joint height exceeding the pad or climbing to the top of the metal-plated end cap solderable end is acceptable, solder touching the component body (MA). 21. Solder balls/solder splashes: more than 5 solder balls or solder splashes (0.13mm or smaller) per 600mm² is (MA). 22. Solder joints with pinholes/blowholes: one solder joint having one (or more) is (MI). 23. Crystallization phenomenon: white residues on the surface of the PCB, solder terminals, or around terminals, white crystallization on the metal surface. 24. Dirty board surface: unclean areas that cannot be detected within 30 seconds at arm’s length are acceptable. 25. Poor glue application: adhesive located in the solder area, reducing the width of the solderable end by more than 50%. 26. PCB copper foil lifting. 27. Exposed copper on PCB: exposed copper width greater than 0.5mm is (MA). 28. Scratches on PCB: scratches not reaching the substrate. 29. Yellowing of PCB: PCB turning yellow after passing through a reflow oven or repair and differing from the PCB color. 30. Bending of PCB: deformation exceeding 1mm (300:1) in any direction over every 300mm is (MA). 31. PCB inner layer separation (bubbles): areas with bubbling and delamination not exceeding 25% of the distance between plated holes or internal wires (MI); bubbling between plated holes or internal wires (MA). 32. PCB contaminated with foreign matter: conductive (MA); non-conductive (MI). 33. PCB version error: according to BOM, ECN. 34. Gold finger soldering: soldering position falling within 80% from the edge of the board is (MA).
Inspection Standards for PCBA Boards in the DIP Post-Soldering Workshop
4. Inspection Standards for PCBA Boards in the DIP Post-Soldering Workshop 01. DIP component solder joint cold soldering: use a toothpick to lightly poke component pins; if they can be moved, it is cold soldering. 02. DIP component (solder joint) short circuit (solder bridge). 03. Missing DIP components. 04. DIP component lead length: Φ≤0.8mm → lead length less than or equal to 1.5mm; Φ＞0.8mm → lead length less than or equal to 2.0mm, special lead cutting requirements excluded. 05. Incorrect DIP components. 06. DIP component polarity reversed or incorrect, causing burning or explosion. 07. DIP component leg deformation: pin bent more than 50% of pin thickness. 08. DIP component floating high or lifted: refer to IPC-A-610E, based on assembly depending on special circumstances. 09. DIP component solder joint solder spikes: spike height greater than 1.5mm. 10. DIP components not identifiable (printing unclear). 11. DIP component legs or bodies oxidized. 12. DIP component body damaged: surface damage without exposing internal metal materials. 13. DIP components using non-designated suppliers: according to BOM, ECN. 14. PTH hole vertical filling and surrounding wetting: at least 75% vertical filling, leads and hole walls at least 270º wetting. 15. Solder balls/solder splashes: more than 5 solder balls or solder splashes (0.13mm or smaller) per 600mm² is (MA). 16. Solder joints with pinholes/blowholes: one solder joint having three (or more) is (MI). 17. Crystallization phenomenon: white residues on the surface of the PCB, solder terminals, or around terminals, white crystallization on the metal surface. 18. Dirty board surface: unclean areas that cannot be detected within 30 seconds at arm’s length are acceptable. 19. Poor glue application: adhesive located in the solder area, reducing the width of the solderable end by more than 50%. 20. PCB copper foil lifting. 21. Exposed copper on PCB: exposed copper width greater than 0.5mm is (MA). 22. Scratches on PCB: scratches not reaching the substrate. 23. Yellowing of PCB: PCB turning yellow after passing through a reflow oven or repair and differing from the PCB color. 24. Bending of PCB: deformation exceeding 1mm (300:1) in any direction over every 300mm is (MA). 25. PCB inner layer separation (bubbles): areas with bubbling and delamination not exceeding 25% of the distance between plated holes or internal wires (MI); bubbling between plated holes or internal wires (MA). 26. PCB contaminated with foreign matter: conductive (MA); non-conductive (MI). 27. PCB version error: according to BOM, ECN. 28. Gold finger soldering: soldering position falling within 80% from the edge of the board is (MA).