臺灣博碩士論文加值系統

本論文探討BGA基板端錫球，在不同溫度條件與夾頭速率下的強度差異。主要針對96.5Sn/3.5Ag，進行包含潛變試驗的各項實驗，並建立相關的數值模型。除了利用不同成份的植球試片進行實驗，也透過切割實際PBGA商品，來探討其錫球接點強度可靠與否。各項實驗如：時效作用、強度因溫度/夾頭速率而異的關係、潛變模型、都透過實驗值的曲線嵌合來獲得，另外經由試片破壞面觀察也了解相關的破壞機制。
在時效實驗中，Sn-Pb錫球接點強度會隨時間不斷遞減，且破壞面會由撓性轉移至脆性，而無鉛試片的時效作用也會在某段時間後達到穩定，但破壞轉移現象並不明顯。透過不同陣列配置的試片之剪力測試，與單顆錫球接點的球剪實驗，可發現試片各接點的強度均勻性良好，實驗過程中無某顆錫球會先行斷裂。以單一方程式來描敘錫球接點在不同溫度與夾頭速率下的強度變化，所獲得的曲線嵌合效果頗佳；但低溫實驗結果數據不足，此方程式尚不能應用至低溫狀態。至於潛變試驗中，所建構的數學模型，不僅可大致嵌合所有的實驗值，且其中的n、Q值也合理獲得。

The mechanical characteristic of the solder ball joint on the board level of BGA was studied at certain conditions. The lead-free solder material of 96.5Sn/3.5Ag was chosen to undergo several experiments such as aging effect on strength, strength decaying by the temperature increasing, creep behavior on different temperature or applied loading. Some mathematical model was adopted or built up to fit the experimental data and the observation in the fracture surface by SEM was also proceeded to interpret the fracture mechanism.
By the way of applying some different array patterns to shear testing or operating the ball shear test on single solder ball, it could be concluded that the strength allotted to the solder array was uniform. On the aging test, the joint strength of 63Sn/37Pb solder ball decreased by the time passed, and the fracture surface transferred from ductility to brittle. It is significant of difference in strength influenced by different temperature or loading rate and one experimental model was obtained in fitting all the data in good agreement. As to the aspect of creep, one reasonable value of stress exponent (n) or activation energy (Q) was settled on the modified Arrhenius-type power law.

一.導論…………………………………………………………………1
二.研究動機……………………………………………………………4
三.文獻回顧
3.1材料組成………………………………………………………6
3.2尺度與形狀……………………………………………………8
3.3 迴銲過程……………………..……………………………….9
3.4 測試方法……………………………..………………………11
3.5 錫球接點觀察與微結構分析……………..…………………13
四.相關黏彈/塑性理論與數值模型
4.1不同負載速率及溫度對銲錫強度的影響……………………15
4.2潛變行為………………………………………………………17
五.研究方法
5.1 試片製作…………………………………………………..…22
5.2 儀器設備……………………………………………………..24
5.3 測試方法…………………………………………………..…26
六.實驗數據結果
6. 1 63Sn/37Pb、96.5Sn/3.5Ag的剪力強度受時效影響之結果..29
6.2 不同溫度/夾頭速率下Sn-Ag的剪力強度差異與數值模型..31
6.3 96.5Sn/3.5Ag受剪力作用下的潛變行為與數值模型…….…34
6.4 固定夾頭速率下Sn-Pb剪力強度在不同溫度間的差異……35
6.5不同無鉛材料間的剪力強度差異…………………………….36
6.6 不同陣列下的剪力強度差異……………..……………..…...38
6.7 PBGA剪力強度受時效影響之結果…………....…….……...39
6.8固定夾頭速率下PBGA剪力強度在不同溫度下的差異……40
6.9不同夾頭速率下拉力和剪力強度的差異…………..…….…..42
七.結果與未來展望…………………………………………………….44
參考文獻
附表
附圖

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