Bubbles Formation on FPC Flexible Circuit Boards
Causes:
- Narrow trace spacing and high trace profiles during screen printing.
- Solder mask failure to fully cover the substrate, allowing trapped air or moisture.
- Trapped gas expanding due to heat during curing, causing excessive trace rise.
Solution:
Visually inspect solder mask application during screen printing. Monitor electroplating process for precise current control.
Solder Masks and Pinholes in FPC Boards
Causes:
- Excessive residual ink accumulation from delayed paper printing.
- Low mesh count on the screen and dirt on the photoplate.
Solution:
Ensure timely paper printing and use a high-mesh screen. Regularly check photoplate cleanliness.
Blackening Signs on Copper Foil Lines
Causes:
- Improper drying or contamination before solder mask application.
Solution:
Inspect copper foil for oxidation during screen printing.
Dirt and Unevenness on FPC Boards
Causes:
- Airborne particles causing dirt and uneven surfaces from improper paper printing.
Solution:
Maintain clean room standards, clean regularly, and ensure timely paper printing.
Ghosting and Cracking Issues
Causes:
- Poor alignment and residual ink in screen causing ghosting.
- Insufficient exposure leading to cracking during the exposure process.
Solution:
Secure paper with positioning pins, remove residual ink promptly, and calibrate exposure settings properly.
Inconsistent Color and Skip Printing
Causes:
- Discrepancies in squeegee passes and ink mixing.
- High electroplating current causing skip printing.
Solution for PCB Printing:
- Ensure consistent squeegee passes on both sides of the PCB.
- Avoid mixing new and old inks during the printing process.
- Control the electroplating current for optimal results.
- Check the squeegee blade for any gaps or damage.
For all your PCB manufacturing needs, feel free to reach out to us.
If you have any questions or require assistance, please contact us.
