近年來，由於電子產品追求輕、薄、短小及高速，使得封裝體採用直接晶片接合技術之比率日漸提高，而當中以覆晶方式之封裝產品成為主流。隨著I/O的密集化發展，可利用電鍍銅柱與熱超音波等方式，不但可做到精細間距(<100μm）以下之尺寸，而且省去覆晶構裝必須建構錫球下的金屬合金，使得成本與製程時間有效降低。再者，為了探討影響封裝體可靠度之參數，因在節省實驗成本之考量下，乃進行反應曲面法分析，以分析封裝體之疲勞壽命。
　　本文使用ANSYS10.0有限元素分析軟體進行分析，施予直接晶片接合封裝體從 -25℃ 至 125℃ 之溫度循環負載，其中錫球考慮為彈塑性變形，其它材料皆視為彈性。在分析時採用全域/局部模型分析法，使其達到精準性與收歛性，然後藉由A.Syed所提出之疲勞壽命公式，預測直接晶片接合封裝體之疲勞壽命。
　　為了探討各控制因子對應變能密度平均值及封裝體疲勞壽命之
影響，乃對直接晶片接合封裝體進行單一因子設計分析，其結果顯
示，較大之銅柱高度、錫球體積及底填膠楊氏模數，與較小之銅柱半
徑、銅柱溼潤深度、底填膠熱膨脹係數、印刷電路板楊氏模數及印刷
電路板熱膨脹係數，皆能有效提昇封裝體之疲勞壽命。然而經由多因
子最佳組合設計，封裝體之疲勞壽命可提昇至1594次。
　　在進行最佳化設計之前，先以部份因子設計篩選影響性顯著之控
制因子，再分別以雙反應與混合反應曲面法建構迴歸模型，並以反應
曲面法配合基因演算法進行最佳化設計，及討論雙反應與混合反
應曲面法獲得之結果。最後，由結果可知因子間之交互作用並不顯
著，而此反應曲面法配合基因演算法最佳化設計與多因子最佳組合設
計結果相同，對封裝體之疲勞壽命可提昇至1594次。

In recent years, with the character of frivolity, short size and high speed, the application of the Direct Chip Attach technique on the packages has gradually increased. Among those techniques, the flip chip type became the mainstream in the product market. As the fine pitch is developed, both the electroplated copper column and the thermosonic skill are efficient not only to make fine pitch, but also to save the UBM required for the solder ball of the flip chip so that the costs and the fabricating time can be reduced. Furthermore, in order to analyze the effect of each parameter on the reliability of the package, the response surface method is applied to analyze the fatigue life of the package for the purpose of saving costs of the experiment.

The ANSYS10.0 finite element analysis software is employed as well as the Direct Chip Attach package is subjected by the thermal cycle of -25℃～125℃. The solder ball is considered as elasticplastic while other components are treated as elastic. The Global/Local method is adopted for analysis to achieve certain accuracy and convergence. Based on the fatigue life formula proposed by A.Syed, the fatigue life of the Direct Chip Attach package is accordingly predicted.

In order to analyze the effect of each factor on an average value of the strain energy density and the fatigue life of the package, the single-factor design analysis on the Direct Chip Attach package is conducted. It shows that the fatigue life of the package increases along with the increases of the height of the copper, the volume of the solder ball and Young’s Modulus of the under fill as well as the reduction of the radius and the wetting of the copper, CTE of underfill, Young’s Modulus and CTE of PCB. The fatigue life of the package can further increase up to 1594 times in accordance with the application of the optimal combination design of multi-factors.

Prior to the process of the optimal design, the most significant factors are chosen by the fractional factorial design. The regressive models are set up by the double response surface method and the mixed response surface method, respectively. Furthermore the genetic algorithm combined with the response surface method is applied to obtain the optimal design, and the results obtained by both two methods are discussed. Finally, it is found that the interaction among each factor is not significant, the results of optimal design obtained by the genetic algorithm combined with the response surface method and the optimal combination design of multi-factors are coincidental, and the fatigue life of the package can increase up to 1594 times.

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