In the semiconductor enterprises, despite great efforts, minimizing time-to-market for new product and improve existing products reliability still remained as a challenging goal yet to be achieved by all. The complexity of the interactions between the non-linear behaviors of materials such as Molding Compound (MC); and Die Attach Material (DAM) with the production tools and package geometry is still not well understood. Unfortunately, in many occasions, the end effect of these interactions could dictate the reliability and quality of the package and may come too late in the design-for-manufacture cycle. In this study, simulation technique is adopted to perform upfront mold-filling analysis to minimize process and product reliability risks such as short molding and wire sweep for new production platform which is with high-density-multiple-strand LF design. The effect of balance compound flow during cavity fillings, gel time, and viscosity and their interactions are also numerically and experimentally investigated. The evaluations indicated that inherent deficiency resulted from mold design for high-density LF design is difficult to overcome by improving molding compound rheology. The usefulness of the standard parameters such as viscosity and gel time provided by compound supplier is also examined. A quantifiable measurable is also developed in this study based on adhesion strength and the interfacial stresses generated from numerical models. These stresses are generated by subjecting the virtual package to a temperature change of -65°C to 150°C. A group of eight DAMs that consists of one control and seven potential choices of DAMs are evaluated using this developed technique. The best three predicted types of DAMs are then built with qualification samples. These samples are then subject to reliability test to validate the effectiveness of the developed technique. The developed measurable is proven to be effective to shorten the evaluation cycle for a robust package.
展开▼
