Probe test failure analysis of bond pad over active structure by modeling and experiment

Abstract

The framework of this paper is to develop a DOE study for different pad structures and probe over travel (OT) parameters for both modeling and experimental tests on a wafer with bond pads placed over active structures. In modeling, a nonlinear finite element contact model is developed for the probe tip surface and the bond pad surface. The relationship between probe tip force and probe over travel distance through the probe beam is analytically derived. Modeling gives the results with different OT, probe tip type with different diameters, probe tip probe scrub. The probe damage test is designed with different OT and different bond pad structures, damage is accessed versus the number of probe tip touchdowns. A DOE study combined with both modeling and experiment is conducted with different BPOA parameters. In addition, an equivalent comparison between probe damage and wire bonding is made to show how the probe test and wire bonding process can affect bond pad over active area structures.