Photoimageable Liquid Solder Masks with High Resolution Properties
By H. Ahne, W. Plundrich, 1. Zapf, Siemens AG - RadTech Europe Conference 1989Details of newly developed photo-patternable solder masks based on polyether resins with photo-crosslinkable side groups are reported.The synthesis of the basic photopolymers follows a chlorine-free route by addition of olefinically unsaturated isocyanates