DES: The Pattern Formation Workhorse
After photoresist is exposed with the circuit pattern, the panel enters the three-stage DES process. Develop: sodium carbonate dissolves unexposed resist, revealing bare copper in areas that will become spaces between traces. Etch: alkaline etchant (ammoniacal copper chloride) dissolves exposed copper, leaving only resist-protected copper. Strip: sodium hydroxide removes remaining resist, revealing the final circuit pattern.
Our workshop operates 3 dedicated DES lines - including the DES acid etching line GL231108B1027A (1 unit) plus Atotech and Manz systems - providing capacity and redundancy for continuous production.
Fine-Line Etching Control
At 3/3 mil trace/space, etch factor (ratio of vertical depth to lateral undercut) becomes critical. Alkaline etching undercuts the resist edge as it etches downward. Our DES lines maintain maximum etch factor through optimized spray nozzle configuration, etchant chemistry, and conveyor speed. Automated titration analyzes etchant concentration every few minutes and adjusts automatically.
