Characterization of Die Attach Failure Modes in Leadless Chip Carrier (LCC) Packages by Auger Electron Spectroscopy

Failure to attach an IC die to its side-braze or leadless chip carrier (LCC) package can represent a serious problem in integrated circuit assembly. Consequently, the need to understand the mechanisms involved in furnace eutectic die attach failure is very critical. The purpose of this experimental investigation was to characterize the various die attach failure modes occurring in the furnace eutectic die attach process of LCC packages utilizing Pb/In/Ag preform material. Results from analytical investigations utilizing surface analysis techniques on a large number of sample die attach failures in LCC´s are presented. An explanation of the causes and mechanisms involved in furnace die attach failure are proposed from both the experimental analytical results obtained and from theoretical investigations.