| abstract |
PURPOSE: To prevent the softening of a soldering resist mask by incorporating a specified compd. n CONSTITUTION: This radiation polymerizable mixture contains a compd. having at least two terminal ethylenic unsatd. groups and capable of forming a crosslinked polymer by radical-initiated addition chain polymn., a polyemrizable binder contg. methacrylic acid units, methacrylic ester units and 40-65wt.% styrene units, a silicic acid or silicate-base fine mineral pigment, a polymn. initiator activated by radiation, a compd. having at least two epoxy groups in one molecule and a thermally activatable polyaddition initiator for epoxy groups. The softening of a soldering resist mask using this mixture can be prevented and dryability, photosensitivity, resolving power and solderability can be improved. n COPYRIGHT: (C)1991,JPO |