The PCB circuit board manufacturing process is fraught with diverse challenges, prompting process engineers to conduct detailed investigations for root cause analysis and countermeasures. This discussion aims to systematically address potential problems within the equipment domain, encompassing people, machines, materials, and conditions.
Key Points:
- Equipment-Focused Analysis:
- Process engineers conduct forensic analysis to identify issues in the manufacturing process.
- Discussion centers on equipment-related factors, including people, machines, materials, and conditions.
- Utilization of Pretreatment Equipment:
- Examination of various pretreatment equipment processes, such as inner layer pretreatment lines and electroplating copper pretreatment lines.
- Example: Solder Mask Pretreatment Line:
- Brushing (2 groups) -> Water washing -> Pickling -> Water washing -> Cold air knife -> Drying section -> Sun plate closing plate -> Discharging closing plate.
- Brushing Challenges and Solutions:
- Brush wheel specifications impact board surface roughness and ink-copper adhesion.
- Long-term use may lead to uneven brush placement, causing issues like “dog bones” and line deformation.
- Brushmark tests and regular adjustments are essential, along with proper lubrication.
- Water Washing and Oxidation Issues:
- Inadequate washing, poor water quality, or impurities can result in copper surface contamination.
- Dry or saturated water-absorbing rollers hinder effective water removal, causing vacuoles, especially around via holes.
- Board surface oxidation occurs during material discharge if residual heat is not managed.
- Quality Control Measures:
- Monitoring water pH and using infrared rays for residual temperature measurement.
- Two sets of suction wheels for alternate cleaning.
- Regular confirmation of air knife angles and inspection of drying section air duct integrity.
Conclusion: The PCB circuit board pretreatment process demands meticulous attention to equipment-related challenges. From brushing issues affecting board surface quality to water washing and oxidation concerns, implementing quality control measures is crucial for consistent and reliable manufacturing outcomes.
