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  • 學位論文

富錫端 Sn-Ag-Co-Ni 四元系統液相線投影圖與 Sn-Ag/Co反應偶之界面反應

Liquidus projection of Sn-Ag-Co-Ni quaternary system at the Sn-rich corner and interfacial reactions in the Sn-Ag/Co couples

指導教授 : 陳信文

摘要


軟銲是電子產品最主要之連接技術,在軟銲的過程中,銲料熔湯與基材濕潤,隨後溫度下降,銲料合金凝固生成銲點。銲點的生成相與銲點的性質息息相關。Sn-Ag合金是市面上最常見的商用銲料,研究上發現微量Co的添加可以有效改善過冷與提昇銲點機械性質。Ni是最常用的擴散阻障層材料,Co則被視為有潛力的材料,近日則亦有以Co-Ni為擴散阻障層之研究。在使用Sn-Ag-Co軟銲合金與Ni-Co擴散阻障層之製程中,除了介金屬相之生成外,亦會有部分基材融入銲湯,形成Sn-Ag-Co-Ni金屬熔湯。了解Sn-Ag-(Co)/(Co,Ni)界面反應以及Sn-Ag-Co-Ni熔湯固化行為,對銲點之品質十分重要。液相線投影圖為探討固化重要工具,因此本研究探討Sn-Ag-(Co)/(Co,Ni) 界面反應中其中一種Sn-Ag/Co的界面反應,並測定Sn-Ag-Co-Ni四元系統於富Sn區之液相線投影圖。Sn-Ag-Co-Ni四元系統,由Sn-Ag-Co、Sn-Ag-Ni、Sn-Co-Ni和Ag-Co-Ni四個三元系統組成。文獻中目前並無Sn-Co-Ni系統的液相線投影圖,因此本研究先行探測Sn-Co-Ni液相線投影圖,然後再探討富Sn區之Sn-Ag-Co-Ni四元系統液相線投影圖。成果顯示Sn-Co-Ni三元系統之首要析出相都為末端相或二元的介金屬相,分別為β-Sn、CoSn3、CoSn2、CoSn、(Ni,Co)3Sn2、(Ni,Co)、Ni3Sn4、與Ni3Sn相。其中(Ni,Co)3Sn2為Co3Sn2與Ni3Sn2之連續固溶體,但是並未發現有三元化合物相為首要固化析出相。Sn-Ag-Co-Ni四元系統的部分,於95at.%Sn以及90at.%Sn皆有四個相區,分別是Ag3Sn、CoSn2、CoSn與Ni3Sn4相,而相區的邊界則有明顯的差別。界面反應方面於250oC液/固界面反應時CoSn3相為Sn-Ag/Co之主要界面生成相。200oC、150oC的固/固界面反應則是有兩種介金屬相生成,分別是CoSn3相以及Ag3Sn相。除此之外銲料中Ag的含量會影響此兩種介金屬相的生長。

並列摘要


Soldering is one of the most important joining technologies in electronic products. During the soldering processes, the molten solders wet the substrates first, and then solidify with lowering temperatures. The phases formed at the joints are critical to the properties of the solder joints. Sn-Ag solders are widely used commercial solders. It has been found that a small amount of cobalt addition can effectively reduce undercooling and improve its mechanical properties. Nickel is the most commonly used diffusion barrier, and (Co,Ni) has also been investigated as possible diffusion barrier material. In the soldering process with Sn-Ag-Co alloys and (Co,Ni) barrier layer, in addition to the formation of intermetallic compounds by interfacial reactions, substrate dissolution occurs, and a Sn-Ag-Co-Ni melt is formed. Understanding of the Sn-Ag-(Co)/(Co,Ni) interfacial reactions and the solidification behaviours of Sn-Ag-Co-Ni melts are important. Liquidus projection is an essential tool for the understanding of solidification behaviours. This study thus investigates the Sn-Ag/Co interfacial reactions and the liquidus projection of Sn-Ag-Co-Ni ternary system at the Sn-rich corner. Since there is no information of the liquidus projection of the Sn-Co-Ni system which is an important constituent ternary system of the Sn-Ag-Co-Ni, this study also studies the liquidus projection of the Sn-Co-Ni system. The results indicate the primary solidification phases of the ternary Sn-Co-Ni system are all terminal solid solution phases and binary compounds which are Sn, CoSn3, CoSn2, CoSn , (Ni,Co)3Sn2, (Ni,Co), Ni3Sn4 and Ni3Sn, respectively. Co3Sn2 and Ni3Sn2 form a solid solution, and no ternary compound is found as the primary solidification phase. At the 90at.%Sn and 95at.%Sn of the Sn-Ag-Co-Ni quaternary system, there are four primary phase regions which are Ag3Sn, CoSn2, CoSn and Ni3Sn4.The Sn-Ag/Co couples reacted at 250oC reveal that the CoSn3 phase is the primary intermetallic compound formed at the interface. The reaction rate is lower with Ag addition. Two reaction layers, CoSn3 and Ag3Sn, are formed in the couples reacted at 200 and 150oC.

參考文獻


25. Y. T. Chen, Y. T. Chan and C. C. Chen, Journal of Alloys and Compounds, Vol.507, pp.419-242(2010)
44. S. W. Chen, Y. K. Chen, H. J. Wu, Y. C. Huang and C. M. Chen, Journal of Electronic Materials, Vol.39, pp.2418-2428(2010)
30. M. Jiang, J. Sato, I. Ohnuma, R. Kainuma and K. Ishida, Calphad-Comput Coupling Ph Diagrams Thermochem, Vol.28(2), pp.213-220(2004)
24. Y. H. Chao, S. W. Chen, C. H. Chang, C. C. Chen, Matellurgical and Materials Transaction A: Physical Metallurgy and Materials Science, Vol.39, pp.477-489 (2008)
9. S. W. Chen, Materials Chemistry and Physics, Vol.33, pp.271-276(1993)

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