A Novel Approach to Front-Side Deprocessing for Thinned Die after Backside Failure Isolation
Abstract This paper describes a novel approach for safe handling of the thinned die from the front; a technique that can also be successfully applied to preserve cracked die. The discussion provides details on the characteristics and processes involved in backside reconstruction, thinned die reconstruction, and front-side deprocessing of thinned die. The finished backside reconstruction sample was cross-sectioned for examination using a diamond saw. After 6 hours of bake, no cracking of the thinned die was observed. Front-side deprocessing was then applied to the backside reconstructed sample. The sample remains intact. The technique has proven to be easily applied and highly reliable, and provides a solution for front-side deprocessing for both high pin count ball grid arrays and flip chips.