Common Issues in PCB Manufacturing Process
1. The challenges encountered during the PCB manufacturing process can be complex, requiring process engineers to investigate thoroughly and implement effective solutions. This discussion aims to explore factors within the equipment domain, including people, machinery, materials, and environmental conditions, that may contribute to these issues. We encourage contributions and insights from all participants.
Importance of Pre-Treatment Equipment
2. Utilizing pre-treatment equipment in processes such as inner layer pre-treatment lines, copper electroplating pre-treatment lines, D/F, and solder mask application is vital for successful PCB manufacturing.
Example of PCB Solder Mask Pre-Treatment Line
3. Let’s consider a hard board PCB solder mask pre-treatment line, which typically involves procedures like double groups of brushing, water rinsing, pickling, cold air knife, drying section, UV exposure, and unloading.
Issues with Brushing Process
4. The use of gold steel brushes with brush wheels of #600 and #800 can impact board surface roughness and ink adhesion. Regular maintenance, brushmark tests, and proper adjustment of brush wheel levels are essential to prevent issues like surface irregularities and line distortion. Inadequate water boiling or spray pressure during brushing may lead to copper powder formation and potential short circuits.
Additional Concerns in Pre-Treatment
- 5. Board surface oxidation can cause bubbling or cavities after processing.
- 6. Misplacement of water-retaining rollers may result in acid transfer, while poor water quality can lead to foreign matter on the copper surface.
- 7. Dry or saturated water-absorbing rollers can leave excessive water residue, hindering proper drying and air knife functioning.
- 8. Stacking boards at residual temperatures can lead to copper surface oxidation.
Monitoring and Maintenance Tips
To maintain quality standards:
- Monitor water pH and board surface temperatures.
- Ensure proper water quality and equipment functionality.
- Verify air knife angles daily and check for any damage in the drying section’s air ducts.
