- 期刊
覆晶構裝受熱循環負載作用之疲勞壽命分析與探討
The Analysis on the Fatigue Life of Flip Chip Package Under Cyclic Thermomechanical Loading
摘要
本文針對覆晶構裝體在環境溫度循環負載之下，利用ANSYS有限元素分析軟體模擬覆晶構裝體之熱及機械行為。結果顯示，由於受元件間材料性質差異之影響，使構裝體產生變形。就錫球部分而言，最大應力應變，亦即最大等效塑性變形範圍值，均發生在離模型中心對稱面最遠處（構裝體最外側錫球與晶片接合面處），也是最容易造成疲勞破壞處，在可靠度分析上，使用溫度循環試驗(TCT)，並針對不同的循環數、不同的材質及不同的製程下，分別以疲勞-應力及疲勞-應變方法計算其疲勞壽命。此外，在分析錫球之疲勞壽命時，發現選用3-D模型較2-D模型分析準確。本文亦使用了田口方法中的L9直交表，依錫球的上徑、下徑、寬及高等四個幾何尺寸，做出S-N回應圖表找出錫球幾何形狀的最佳化設計；並做變異數分析(ANOVA)，探討錫球中各幾何形狀對疲勞壽命之貢獻度。
並列摘要
This paper focuses on the flip chip package under the cyclic loading at ambient temperature. The ANSYS is used to simulate the thermal conduction and the mechanical behavior of flip chip package. The results reveal that the deflection is caused by the difference of material properties of the components. For example, the maximum equivalent plastic strain range of solder balls always happens at the farthest place from the symmetrical surface of models and causes the fatigue destruction most easily. In the analysis of reliability, temperature cycle test was employed. The fatigue life was calculated by fatigue-stress and fatigue-strain method individually in different cycles, material properties, and processes. Besides, when analyzing the fatigue life of solder bumps, it was more accurate in the result of using 3-D model then using 2-D model. The S-N response figure and L9 Orthogonal Array Table of Taguchi Method was also employed to find the optimum condition of the up radius, down radius, height, and width of solder in this research. Analysis of Variance was made to probe the contribution of thesegeometric parameters with respect to the fatigue life of solder balls.