Reduction of Vacrel Solder Mask Outgassing
Original Publication Date: 1985-Nov-01
Included in the Prior Art Database: 2005-Feb-19
Vacrel 930* (E. I. du Pont de Nemours & Co.) is used as a solder mask in the manufacture of printed circuit boards (PCBs) or the like. Because Vacrel 930 outgasses at a high rate it can cause poor solderability. The immediate processing of the hot PCBs through final ultraviolet (UV) cure improves solderability. The procedure for improved solderability is as follows: 1. Expose/develop Vacrel. 2. Thermal bake for two hours at 140ŒC. 3. Remove PCBs from oven and immediately process through the final UV cure before boards are allowed to cool.