Contact Resistance of Microbumps in a Typical Through-Silicon-Via Structure

The contact resistance of microbumps in a plastic ball grid array packaging with a through-silicon-via (TSV) structure was characterized. Accordingly, a self-designed TSV daisy-chain circuit was proposed to facilitate the formulation of the measurement paths, and the test samples were made by using a commercialized packaging process to simulate real product behaviors. Using the proposed single model and the complete model for the testing structure, about 25 mQ was measured as the average contact resistance per microbump, and the contact resistance for each microbump was separately extracted between 4 and 60 mQ In addition, decreasing contact resistance due to the annealing effect was observed from two different reliability tests.