Warpage evaluation by a finite element method for 3D-Stacked BGA packages

• Main Authors: Kuo-Chi Tseng, 曾國基
• Other Authors: Jung-Hua Chou
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/98812400754217782912

碩士 === 國立成功大學 === 工程科學系專班 === 93 === 　A numerical investigation of 3D-Stacked BGA packages is conducted to evaluate package warpage during the assembly process by ANSYS. The effects of die thickness、substrate thickness、mold compound thickness and process temperature on warpage are studied so that a set of optimum process parameters is obtained to improve the assembly yield. 　Computational results indicate a 1.5% difference in warpage between 2D and 3D models. There is a 10% difference in warpage between the 2D simulation and actual results and is considered acceptable. Thus, 2D model is adopted for further simulations. From the simulation results, it is observed that the substrate thickness and mold compound thickness have significant influence on package warpage. Also by decreasing the IR-reflow temperature from 230℃ to 220℃, the package warpage can be further reduced to 3.86mils and meets specification requirement. In other words, a 23% improvement in package warpage can be achieved and the von Mises stress also decreases from 541Mpa to 519Mpa.