Correlation of wafer level wire bond and package level wire bond for bond pad quality evaluation

Abstract

Bond pad quality and reliability evaluation is part of important structure test for wafer fabrication. In order to ensure production consistency, and part of continuous monitoring, as well as new process qualification, bond pad evaluation through wire bond is required. Usually the test was conducted by proceed through standard IC packaging such as wafer saw, die attach and wire bond to simulate actual mass production environment. Optionally this can also be done by using wafer level wire bond. Main advantage of wafer level wire bond is shorter test cycle as compare to conventional package level bonding. This could be a significant time saving especially in the fast pace semiconductor field. Key concern of wafer level bonding is the correlation of bonding performance as compare to real application in the field. In view of this, correlation work has been done to study wire bond responds on wafer level bonding as compare to typical package level bonding. Wire bond DOE was carefully planned and conducted for this evaluation. Ball shear and ball dimension data were collected from both type of bonder. This evaluation will also cover observations and challenges of wafer level bonding, together with the recommended solutions.