DIP Automation Line Case – Post Selective Soldering Cleaning & Inspection
Project Background
The customer is an electronics manufacturer producing mixed-technology PCBs (SMT + DIP).
In their original process, the DIP section had the following issues after selective wave soldering:
- Flux residue remaining on PCB surface
- Manual visual inspection with unstable quality
- Difficulty in detecting solder joint defects under components
- Inconsistent quality control standards
- Limited traceability of inspection data
The customer wanted to upgrade the DIP section into a more automated, standardized, and quality-controlled process.
Process Flow (Upgraded)
Selective Wave Soldering → Inline PCB Cleaning Machine → AOI Inspection → Reject Conveyor
Customer Requirements
Remove flux residue after selective soldering
Improve solder joint inspection accuracy
Reduce manual inspection dependency
Automatically separate NG boards
Increase process stability and repeatability
Our Automation Solution
We provided a DIP post-soldering automation cell, integrating cleaning, inspection, and sorting into an inline process.
✅ 1. Inline PCB Cleaning Machine
Installed directly after the selective wave soldering machine.
Main functions:
Removal of flux residue and contaminants
Improvement of PCB surface cleanliness
Prevention of corrosion and long-term reliability issues
Better visual condition for inspection
The cleaning process ensures the PCB is in optimal condition before entering inspection.
✅ 2. AOI Inspection System (After Cleaning)
After cleaning, PCBs enter the AOI system for solder joint inspection.
Inspection focus:
- Insufficient solder
- Solder bridging
- Missing solder
- Poor wetting
- Solder ball and contamination detection
Key advantages:
- Stable inspection standard
- Reduced human judgment variation
- Higher defect detection accuracy
- Digital inspection records for traceability
This step converts DIP inspection from manual checking → data-driven automated inspection.
✅ 3. Reject Conveyor System
After AOI:
OK boards continue to the next process
NG boards are automatically diverted to the reject conveyor
Benefits:
- Prevents defective boards from flowing downstream
- Reduces operator workload
- Improves overall line control
Project Challenges
- Integration with existing selective soldering equipment
- Ensuring cleaning chemistry compatibility with PCB materials
- AOI tuning for complex DIP solder joints
- Our engineering team handled:
- Interface matching
- Process parameter optimization
- AOI program fine-tuning
Final Results
After automation upgrade, the customer achieved:
✔ Clean PCB surface and improved product reliability
✔ Standardized solder joint inspection
✔ Significant reduction in manual inspection
✔ Lower defect escape rate
✔ Automatic NG board separation
✔ Improved DIP line automation level
The DIP section was transformed from a semi-manual process into a controlled, automated post-soldering quality cell.