PCB Solder Masking
Simplified process flow
Compared to the traditional solder mask process, the number of process steps is reduced to three in the inkjet-based process. Pre-treatment remains crucial for good adhesion. The inkjet printer then applies the solder mask material and uses UV curing so the boards come out tack-free. Post-curing concludes the process.
This simplification saves capital equipment, labor, process chemicals and waste, and reduces handling and the buildup of yield problems. It also cuts the total time to finish a PCB board – a key point in today’s fast-moving electronics business.
Unique characteristics of inkjet
Inkjet technology boasts a number of advantages. First, it is a selective coating technology: material is only deposited where required. This reduces material consumption and avoids the challenge of removing surplus solder mask material.
Second, there is no risk of removing small solder dams between IC contacts. Third, inkjet allows different surface finishes, layer thicknesses and materials. Finally, inkjet has the ability to accurately align and scale the print image to the board.
The PiXDRO JETx-SMP inkjet production equipment is specifically designed for printing solder resist on printed circuit boards. This system enables fast and cost-effective manufacturing of solder mask layers.
The JETx-SMP printer produces solder mask layers with the following specifications:
- Line-space: 75-75 µm
- Edge roughness: 20 µm
- Solder mask openings: down to 100 µm
- >10 µm solder mask thickness on copper
- Layer thickness: 30-80 µm, can be varied over the board to reduce material consumption
- Alignment accuracy: <2 µm using automated fiducial alignment