Failure strength study of silicon die and LCD glass by FEA and experiment

Measurement of failure strength of brittle material is always a challenge. Silicon die and LCD glass are two major brittle components in electronic products. Both of them may fail when subject to a large stress during manufacturing, assembling and in field. In order to assess the risk of failure, both 3-point bending (3PB) and ball-on-ring (BOR) are employed to measure the flexural strength of silicon die and glass in this paper. The samples are taken from actual consumer digital products. It is found that the results from two different testing methods are quite different, which include the values of strength and the failure modes. The failure mechanism and location are also studied using finite element analysis (FEA). Two different cracking modes come out of the test results for both silicon die and LCD glass. One is cracking into many small pieces and this is the main cracking mode. The other is cracking into two half.