Analysis of Warpage Issue in Flip-Chip Ball Grid Arrays

• Main Authors: Jyun-Ling Tsai, 蔡君聆
• Other Authors: Dong-Sing Wuu
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/36747905694254856836

碩士 === 國立中興大學 === 材料科學與工程學系所 === 97 === The thesis seeks to discuss in detail the best material and adhesive dispense matrix combination for reducing the thermal stress (package warpage) effect on a flip chip package at reflow temperature conditions. In this study, the Shadow Moiré Method was utilized to simulate and characterize the warpage performance of a flip chip package on varying reflow temperatures. In regards to the adhesive material properties for the heatspreader, the high glass-transition temperatures (Tg) and low coefficient of thermal expansion (CTE) characteristics show the better warpage performance. In the case of the flip chip package with similar heatspreader adhesive material (X type or M type) but of different type of heatspreader adhesive pattern (4L-type or U shape), the warpage deviations at peak temperature of 260℃ are 0.5 mils and 1.2 mils. This gives the criteria of material properties for choosing the suitable adhesive material. As regarding the heatspreader adhesive dispense pattern, the “four-line + dot shape” shows better results than the “U shape” adhesive pattern, where the warpage performance at peak temperature 260℃ were 1.8 mils and 1.5 mils, respectively. These indicate that the better adhesive pattern would further serve to control the flip chip package warpage.