本實驗針對錫球經過155℃不同時間之時效處理後觀測內部的相變化以及IMC的成長過程，並交叉比對含鉛（Sn-Pb）系列與無鉛(Sn-Ag-Cu)系列Solder與IMC之差異性，並經由時效處理觀測材料的擴散行為，量測錫球經不同時效處理後與錫球Shear Force之變化，並將推球破裂面加以放大觀測，且由電子顯微鏡放大分析接合處Cross-Section之IMC成長行為與Phase的變化，由於Pad 上所鍍的Au造成IMC 之（Au,Ni）Sn4快速成長，使得錫球接合處容易形成脆性破裂的情形，但是在無鉛系列之Cu在Reflow過程中將鍍Ni層覆蓋，阻礙Au與Ni的擴散行為，使得IMC成長趨於緩慢，而Ag3Sn的析出物增強無鉛錫球的抗破裂強度，使得Sn-Ag-Cu系列無鉛錫球改善了BGA錫球接合部位之可靠度。

The Study of Microstructure Analysis of Pb/Sn And Sn/Ag/Cu Solder Ball in BGA Package.

壹. 前言 ……………………………………………………………………… 1
1-1 研究背景 ------------------------------------------------------------------------ 1
1-2 文獻回顧 ------------------------------------------------------------------------ 2
貳. 實驗方法…………………………………………………………………… 6
2-1實驗目的 ------------------------------------------------------------------------- 6
2-2實驗之計畫流程 -------------------------------------------------------------------- 7
2-3本實驗所使用BGA試片之接點部位說明 ------------------------------------ 8
2-3.1.Pad 接合部位---------------------------------------------------------------- 8
2-3.2.Solder Ball接合部位-------------------------------------------------------- 8
2-4試片實驗種類、成分與標示代號之說明 --------------------------------------- 10
2-5熱處理過程 --------------------------------------------------------------------------- 11
2-6推球過程 ------------------------------------------------------------------------------ 12
2-7 BGA試片Cross-Section部位之金相處理 -------------------------------------- 13
2-8試片觀察與分析 --------------------------------------------------------------------- 13
參. 實驗結果…………………………………………………………………… 14
3-1 由剪斷強度分析 -------------------------------------------------------------------- 14
3-2 Pb-Sn系列錫球顯微分析 --------------------------------------------------------- 15
3-2.1.推球後Pad Surface的顯微組織分析 ------------------------------------ 15
3-2.2.BGA Cross-Section 的顯微組織分析 ----------------------------------- 15
A.錫球接合部位之IMC成長行為----------------------------------------------- 15
B.Au、Ni、Sn各成分之擴散情形----------------------------------------------- 16
C.錫球內部之析出物----------------------------------------------------------- 17
3-3 Sn-Ag-Cu系列錫球顯微分析------------------------------------------------------- 18
3-3.1.推球後Pad Surface的顯微組織分析-------------------------------------- 18
3-3.2.BGA Cross-Section 的顯微組織分析-------------------------------------- 18
A.錫球接合部位之IMC成長行為------------------------------------------- 18
B.各成分之擴散情形----------------------------------------------------------- 19
C.錫球內部之析出物----------------------------------------------------------- 19
肆. 討論 ………………………………………………………………………… 21
4-1.由推球值、微接點接合部位之IMC成長以及破裂面探討 ------------------ 21
4-2.顯微組織觀測與探討 ---------------------------------------------------------------- 22
4-2.1.接合部位之IMC成長情形 ------------------------------------------------- 22
4-2.2.含鉛與無鉛錫球成分對微接點接合部位成分之探討 ----------------- 23
4-2.3.155℃高溫時效處理之擴散情形與IMC成長行為之探討 ----------- 23
4-3. BGA Pb-Sn系列與 Sn-Ag-Cu 系列相互比較--------------------------------- 25
4-4. Sn-Ag-Cu 系列加入Cu與Ag之功能探討------------------------------------ 27
4-4.1 加入Ag之功能-------------------------------------------------------------- 27
4-4.2 加入Cu之功能-------------------------------------------------------------- 27
伍.結論 …………………………………………………………………………… 29
陸.參考文獻 ……………………………………………………………………… 31



表目錄
表一、試片分類、處理與編號說明--------------------------------------------------- 34
表二、含鉛系列錫球接合部化合物厚度與時效時間關係整理表--------------- 35
表三、含3%Ag之無鉛錫球接合部化合物厚度與時效時間關係整理表------ 36
表四、含1%Ag之無鉛錫球接合部化合物厚度與時效時間關係整理表------ 36

圖目錄
圖1、The equilibrium phase diagrams of the Ni-Sn binary system--------------- 37
圖2、The equilibrium phase diagrams of the Au-Ni-Sn ternary system--------- 38
圖3、The equilibrium phase diagrams of the Au-Sn binary system-------------- 39
圖4、The equilibrium phase diagrams of the Ag-Sn binary system-------------- 40
圖5、The equilibrium phase diagrams of the Cu-Ni-Sn ternary system--------- 41
圖6、Type A-Reflow 一次、二次之時效處理與剪斷強度關係--------------- 42
圖7、Type B、C、D-Reflow一次、二次之時效處理與剪斷強度關係------ 43
圖8、Pb-Sn系列在155℃時效處理Pad Surface的破裂行為------------------ 44
圖9、Pb-Sn系列推球後之破裂行為------------------------------------------------ 45
圖10、Pb-Sn系列在推球破裂面Pad Surface上Pb的分佈情形-------------- 46
圖11、Pb-Sn系列之接合部位成長曲線圖----------------------------------------- 47
圖12、Pb-Sn系列之接合部位成分分析-------------------------------------------- 48
圖13、在155℃時效處理24小時內Au的擴散行為---------------------------- 49
圖14、在155℃時效處理Au、Ni、Sn的擴散行為----------------------------- 50
圖15、在155℃時效處理Solder內Pb的擴散行為----------------------------- 51
圖16、含鉛系列錫球Au在Solder的分佈情形---------------------------------- 52
圖17、Sn-Ag-Cu系列推球破裂面之情形 ---------------------------------------- 53
圖18、Sn-Ag-Cu系列顯微觀測Ag的析出物------------------------------------ 54
圖19、Sn-Ag-Cu系列Cross-Section顯微觀測----------------------------------- 55
圖20、Sn-Ag-Cu系列之接合部位成長曲線圖----------------------------------- 56
圖21、Sn-Ag-Cu系列之接合部位成分分析 ------------------------------------- 57
圖22、Sn-Ag-Cu系列經時效處理後Au與Cu的擴散行為 ------------------ 58
圖23、Sn-Ag-Cu系列經時效處理後Ni的擴散行為--------------------------- 59
圖24、Sn-Ag-Cu系列經時效處理後Ag的擴散行為-------------------------- 60
圖25、Pb-Sn系列錫球接合部位之顯微分析 ----------------------------------- 61
圖26、Sn-Ag-Cu系列錫球接合部位之顯微分析------------------------------- 62

1. 張恆碩 ”Pb-Sn 及 Pb-Sn-Ag 合金對銅材軟銲反應層研究” 中山大學圖書館(1998).
2. Zequn Mei, Matt Kaufmann, Ali Eslambolchi, and Pat Johnson, “Brittle Interfacial Fracture of PBGA Packages on Electronless Ni/Immersion Au,” Proc. 48th Electronic Component and Technology Conference, pp 952~961,May,1998.
3. Warashina, K., Kariya, Y., Hirata, Y. and Otsuka, M., ”Thermal Fatigue Damage of Quad Flat Pack Leads and Sn-3.5Ag-X(X=Bi and Cu) Solder Joints,” Environmentally Conscious Design and Inverse Manufacturing, 1999. Proceedings. EcoDesign '99: First International Symposium On , pp. 626 -631, 1999.
4. Syed, A., “Reliability and Au Embrittlement of Lead Free Solders for BGA Applications,” Advanced Packaging Materials: Processes, Properties and Interfaces, 2001. Proceedings. International Symposium on ,pp 143-147 ,2001.
5. Ye, L., Lai, Z., Liu, J. and Tholen, A. , ”Recent Achievement in Microstructure Investigation of Sn0.5Cu3.4Ag Lead-free Alloy by Adding Boron,” Advanced Packaging Materials: Processes, Properties and Interfaces, 1999. Proceedings. International Symposium on , pp 262 -267 ,1999.
6. Bradley, E., III and Hramisavljevic, J. , “Characterization of the Melting and Wetting of Sn-Ag-X Solders,” Electronic Components & Technology Conference, 2000. 2000 Proceedings. 50th ,pp1443 -1448, 2000.
7. Oliver, J.R., Liu, J. and Lai, Z. , ”Effect of Thermal ageing On The Shear strength Of Lead-Free Solder Joints,” Advanced Packaging Materials: Processes, Properties andInterfaces, 2000. Proceedings. International Symposium on , pp 152 -157,2000.
8. Li-Lei Ye, Zonghe Lai, Liu, J. and Tholen, A., “Microstructural Coarsening of Lead Free Solder joints During Thermal Cycling,” Electronic Components & Technology Conference, 2000. 2000 Proceedings. 50th , pp 134–137,2000.
9. Gibson, A.W., Choi, S., Bieler, T.R. and Subramanian, K.N., “Environmental Concerns And Materials Issues In Manufactured Solder Joints,” Electronics and the Environment, 1997. ISEE-1997., Proceedings of the 1997 IEEE International Symposium on ,pp 246 –251, 1997.
10. Coyle, R.J., Holliday, A., Mescher, P., Solan, P.P., Gahr, S.A., Cyker, H.A., Dorey, K. and Ejim, T.I. , “The Influence of Nickel/Gold surface Finish on the assembly Quality and Long Term Reliability of Thermally Enhanced BGA Package,” Electronics Manufacturing Technology Symposium, 1999. Twenty-Fourth IEEE/CPMT , pp 23-25.1999 .
11. Levis, K.-M.; Mawer, A. , “Assembly and Solder Joint Reliability of Plastic Ball Grid array with Lead-Free Versus Lead-Tin Interconnect,” Electronic Components & Technology Conference, 2000. 2000 Proceedings. 50th ,pp 1198-1204, 2000.

12. Erich, R.; Coyle, R.J.; Wenger, G.M.; Primavera, A. , “Shear Testing and Failure Mode Analysis for Evaluation of BGA Ball Attachment,” Electronics Manufacturing Technology Symposium, 1999. Twenty-Fourth IEEE/CPMT , pp 16-22, 1999 .