Solder Joint Reliability (SJR) Study of Integrated Heat Spreader (IHS) Packages

This paper discusses the SJR performance and characteristic study for IHS package technology. Limited industry literature for design reference is the key motivator of this IHS base SJR evaluation on various stresses. Both experimental and simulation studies were performed to identify the critical reliability factors impacting the SJR in static compressive, mechanical shock and transient bend stresses. The critical SJR factors on thermo-mechanical fatigue included solder systems, types of preload and board thickness design were investigated. The impacts of ball pitches, board thicknesses and ball attach process in shock loading will be discussed. Furthermore, the sensitivities contributed by ball pitches, board thicknesses and trace orientation design on transient bend were evaluated as well. Beside, the performance trends and failure modes were analyzed to gather better understanding especially on its driving mechanism. As a summary, this paper presents and documents the key influence factors in SJR for electronic package design in IHS configuration.