TSV Modeling Applied To3D Package And Heat Transfer And Load Analysis

With the development of society, semiconductor chips face constant pressure for asmaller size, lower power consumption and higher performance. The technology ofelectronic packaging has developed from two dimensions package which includes onechip to three dimensions package which includes several chips. The packagingtechnology has developed from wire bonding to TSV (through silicon via) as well.Meanwhile, there are lots of critical issues about3D IC integration such as designguidelines and softwares are not commonly suitable in use; Test methods andapplication equipments are lacking; High frequency chips mixed with low frequencychips; the big chips are integrated into the small chips; The smaller bumps are required;How to thin down the chips in the process engineering; thermal processing issues;3Dexpertises, rudimentary knowledge and standards are lacking. TSVs are usuallyachieved in3D integrated circuit; The cost of TSV is more expensive than wire bonding;The high-volume production of TSV is immature; TSV technology usually requiresmuch smaller bumps; The filling of copper and silicon wafer leads to CTE (coefficientof thermal expansion) mismatch when TSVs are made; and The heat dissipation andstress problem of TSV technology, etc. So heat transfer problem and mechanicalstability problem have become a puzzle restricting the development of3D packaging.Based on3D packaging theory, this paper did following work.1. Through using ANSYS, the gold wire package model which has single layerpower chip and the TSV package model which is based on FCB (flip chip bonding)technology are established respectively. Through the substitution of materialparameters, the analysis of heat transfer simulation is made for the two kinds ofprocess model and compared with the highest temperature of these two models. Findthat TSV package model’s temperature is lower than gold wire package model’s for0.4to0.8℃in the equivalent TSV pitch. Obtain the conclusion that the heatdissipation effect of TSV model is much better.2. The heat circuit graphs of the two models are described in using the principle ofthermal resistance. Based on this principle, the heat resistance equations are obtainedand the resistances of both models are compared. Finally, it is found that the aboveconclusions’ reason is due to the TSV model’s resistance is much smaller.3. Analyse the two models’ insufficient, more practical models are designed andthe heat transfer are simulated. Find that the heat dissipation effect of TSV model is still much better. Through designing the heat circuit graphs of the two models andcomparing the resistances one can find the reason.4. At last, load model based on TSV technology was designed, and found that themost dangerous region in the model was located in the frontier solder ball.