Summer 1983

Automatic pH Controlled Replenishment of Developers for Aqueous Processable Dry Film Resists

This article reviews factors involved in using pH to monitor and control aqueous development A pH·control/ed replenishment system automatically maintains a constant speed for aqueous· processed resists in conveyorized developers. This gives more consistent resist performance. fewer developing problems. increased productivity. and reduced cost compared to "batch" developing, A pH·controlled developer is easily ptaced in-line with an etcher and resist stripper Panel handling is reduced and inner·layer fabrication is Simplified

Earl T. Hackett and Robert H. Wopschall, Riston Products Division of DuPont