20.3
Repeatable method for automated decapsulation of silver alloy wire packages

Thursday, November 5, 2015: 1:30 PM
Meeting Room D137 & 138 (Oregon Convention Center )
Dr. MATTHEW J. Lefevre , JP Kummer, Evry, France
Mr. Emmanuel Noraz , ST Microelectronics, Grenoble, France
Dr. Damien Veychard , ST Microelectronics, Grenoble, France

Summary:

Over the past several years there has been a large industry wide effort to change over from gold bonding wires to copper in order to minimize production costs. In certain cases this is not possible due to the relatively high hardness values of Cu [1], which leads to reliability issues in the manufacturing process. Silver (Ag) wire has been proposed and successfully implemented in many instances where Cu wire was not practicable. Unfortunately, currently integrated decapsulation methods severely damaged or destroyed the silver wires and bonds, making it impossible to perform production controls and failure analysis. In this article we present a reliable and repeatable automated method to expose these die and wire bonds. By adding a dilute iodine solution to the nitric acid in an acid decapsulator, these packages can be fully opened without degrading the silver wires, allowing both mechanical and electrical testing on these devices.