An Experimental Investigation Into Thin Silicon Die Strength Evaluation

Thinner silicon die is the key to reach the target of thin semiconductor product in 3D assembly, stacked die cross-hand design has high risk to cause silicon die which thickness less than 100 micron damage during wire bond and compound molding processes. Thus the thin silicon die quality and fracture strength become more and more challenges. Therefore, the thin silicon die strength measurement method and the result accuracy is important for package structure design and manufacturing process development.The three-point bending is a standard measurement method for silicon die strength evaluation in global semiconductor factories. However, the classical theory used to convert the experimental load into fracture strength value is unreasonable due to variation 960 MPa and maximum strength 1,544 MPa as the die thickness is 50 micron. In this work, the cantilever beam testing was carried out to explore thin die strength. Finally, the analyzed data by cantilever beam test exhibited more stable than three point bend test result, successfully evaluate the more accurate die fracture strength, especially for silicon die thickness less than 100 micron, enhance around 80% data variation.