PCBA Tech - What are the PCBA inspection standards conducted by SMT factory?

Shenzhen PCBA manufacturer take you to familiarize yourself with some PCBA production processes in SMT technology shop. What are the inspection requirements for PCBA proofing in SMT technology patch processing shop during the production process?

1. First of all, pre-production materials for SMT technology shop

Smt related technical operators check the specifications, models and sizes of the baseboard according to the drawing of PCBA proofing product patch processing or feeding specifications. The latitude and longitude direction, the length and width dimensions and the verticality of the base plate are within the specified range of the drawings.

2. Smt technology equipment begins to print screen plates: First, check if the mesh mesh, screen tension and film thickness meet the required requirements; Then check the graphic integrity without pinholes, gaps or residual film; Check with the Photo Base, the graphics are aligned in size, line width, line spacing, connector disk size, or character markers.

3. Surface cleaning: The surface of the chemically cleaned PCBA board should not be oxidized or polluted, and should be dry after cleaning.

4. Printing requirements for PCBA board: Check the graphic integrity of the lines, without breaks, pinholes, gaps or short circuits; Check with the photographic background, the graphics are aligned in size, line width and line spacing, and the error is within the allowable range.

5. Etching on PCBA circuit board: Check the graphic integrity of the line without breaks, pinholes, gaps or short circuits; Check with the photo negative, no etching (too thin line) or insufficient etching (too thick line).

6. PCBA circuit board resistance: check the integrity of the resistance graphics, without leaks, pinholes, notches or ink penetration, upper disc, excess ink points; Consistent with line graphic positioning dimensions, error is within allowable range. Then continue to check the solidification degree of the solder. The solder layer on the copper conductor surface should be tested with pencil. The pencil should be harder than 3H. Finally, check the solder binding force of PCBA circuit board. The solder layer on the copper conductor surface of PCBA board should be bonded and pulled up with adhesive tape. There should be no flaking solder on the tape.

7. Character markers on front and back of PCBA circuit board: The relevant responsible person of SMT product inspection department strictly checks the graphic integrity of the character markers on PCBA boards in accordance with the implementation standards, and there are no prints, pinholes, gaps or ink penetration, plating or extra ink points; Consistent with the line graphic positioning size, the error is within the allowable range, and the character marker can be correctly identified.