Microwave induced plasma decapsulation of stressed and delaminated high pin-count copper wire bonded IC packages

The applicability of Microwave Induced Plasma (MIP) afterglow etching in copper wire bonded IC package decapsulation is investigated. In-situ monitoring of the processing temperature during plasma etching is conducted with SOT23 components with diode devices inside as temperature sensor. Parameters that influence etching temperature and efficient MIP etching process are discussed. Aged epoxies in molding compound encapsulants after thermal stress tend to be more resistant to conventional acid etching. IC packages that went through temperature cycling are decapsulated by MIP etching to evaluate the capability of this technique. High pin-count 18 μm palladium coated copper wire bonded BGA package with delamination defects are decapsulated without process-induced damage by MIP afterglow etching and the results are compared with cold acid etched components.