Routine PCB board inspection standards

What are the inspection standards for a PCB board?
Let's first understand the shortcomings of quality inspection standards
1.Serious defect(CR):Any defect that may cause harm to the human body or machine or endanger life safety,such as inconsistent safety/combustion/electric shock,etc.
2.Main Disadvantages(represented by MA):Disadvantages that may cause product damage,functional abnormalities,or affect product lifespan due to material reasons.
3.Minor defects(MI indicates):do not affect product function and service life,some appearance defects,as well as minor defects or differences in mechanical assembly.
Inspection conditions for two PCB boards:
To prevent component contamination,you must choose EOS/ESD fully protected gloves or fingertips and wear an electrostatic ring for operation.The light source is a white fluorescent lamp,and the light intensity must be above 100 lux,visible within 10 seconds.
2.Inspection method:Place the product to be inspected about 40 centimeters away from the eyes,at an angle of 45 degrees up,down,left,and right,and examine it with the naked eye or a triple magnifying glass.
3.Inspection standard:(Sampling shall be conducted at a sampling level of QS9000 C=0 AQL=0.4%;if the customer has special requirements,it will be determined based on the customer's acceptance criteria)
4.Sampling plan:MIL-STD-105E LEVEL ordinary single sampling
5.Judgment criteria:Critical defect(CR)AQL 0%
6.The main drawback(MA)is that AQL is 0.4%
Standard for inspection items of PCBA boards in the SMT SMT SMT mounting workshop
Spot welding of SMT parts
02.Cold welding of SMT parts solder joints:Gently touch the pins of the parts with a toothpick.If they can be moved,it is cold welding
03.Short circuit of SMT parts(solder joints)(inside the bridge)
04.Missing SMT parts
05.Problem with SMT parts
06.Reversed or incorrect polarity of SMT parts,resulting in combustion or explosion
07.Various SMT accessories
08.SMT part reverse side:text side facing down
09.SMT parts placed side by side:The length of the chip assembly is 3mm,and the width of 1.5mm does not exceed five(MI)
10.SMT Parts Tombstone:Flipping of Chip Component End
11.SMT part foot offset:Side offset less than or equal to 1/2 of the width of the solderable end
12.Floating height of SMT parts:The distance between the bottom of the component and the substrate is 1mm
13.SMT part foot height:The lifting height is greater than the part foot thickness
14.SMT parts are uneven and not tin plated
15.Unable to recognize SMT parts(blurry printing)
16.SMT part body oxidation
17.SMT component body damage:capacitor damage(MA);Resistance damage is less than 1/4 of the width or thickness(MI)of the component;IC damage in any direction is less than 1.5mm(MI),exposing internal materials(MA)
18.Use of Non Designated Suppliers for SMT Parts:According to BOM,ECN
19.SMT parts solder joint solder head:The height of the solder head is greater than the height of the part body
20.Insufficient soldering of SMT parts:The minimum solder joint height is less than 25%of the solder joint thickness plus the height of the solderable end plus 0.5mm.The smaller of the two is(MA)
21.SMT parts eat too much:the maximum solder joint height exceeds the solder pad or climbs to the top of the solderable metal coating end cover for acceptance,and the solder joint contacts the component body(MA)
22.Welding balls/slag:≥5 welding balls(MA)or welding spatter(0.13mm and below)per 600mm2
23.Pinholes in solder joints:One solder joint has multiple(including)as(MI)
24.Crystallization phenomenon:There is white residue on the surface of the PCB board,welding terminals,or around the terminals,and white crystals on the metal surface
25.Unclean surface of wooden board:Within 30 seconds,it cannot be found within a long arm distance and is not clean
26.Poor dispensing:The glue is located in the area to be soldered,reducing the width of the soldered end by more than 50%
26.Poor dispensing:The glue is located in the area to be soldered,reducing the width of the soldered end by more than 50%
27.PCB copper foil detachment
28.PCB exposed copper:If the exposed copper width of the circuit(gold finger)is greater than 0.5mm,it is MA
29.PCB scratches:The substrate cannot be seen from the scratches
30.PCB burning yellow:The PCB burns yellow in the reflow furnace or after rework,and the color of the PCB does not match the color of the PCB
31.PCB bending:bending deformation in any direction exceeding 1mm(300:1)/300mm as(MA)
32.PCB inner layer separation(bubbles):The area of bubbles and delamination does not exceed 25%(MI)of the distance between plating holes or inner layer lines;Blistering between plating holes or internal lines(MA)
33.PCB with foreign objects:conductive(MA);Conductivity(MI)
34.PCB version error:Based on BOM,ECN
35.Gold finger dipping in tin:The dipping position is within 80%of the edge of the board(MA)