體積效應對SnAgCu無鉛銲料與Ni銲接反應的影響

The Effect of Volume on the Soldering Reaction between SnAgCu Solders and Ni

楊素純(S.C. Yang) ； 何政恩(C.E. Ho) ； 高振宏(C.R. Kao)

《材料科學與工程》 37卷4期 (2005/12) Pp. 230-234

https://doi.org/10.6409/JMSE.200512.0230

摘要

本研究之目的乃在探討SnAgCu銲料之Cu濃度與體積變化對銲接反應的影響。本實驗係以760、500及300μm三種不同直徑的銲錫球，來對開孔375μm的Ni銲墊進行銲接。其中SnAgCu銲錫球的Cu濃度分別爲0.6、0.5及0.4 wt.%。研究發現，共有(Cu,Ni)6Sn5與(Ni, Cu)3Sn4兩種介金屬(intermetallic compound)會於銲點界面生成。有趣的是，此兩種介金屬的形態係與Cu濃度及銲料體積息息相關。隨銲料體積的縮小（或銲料有效之Cu濃度的下降），原本連續之(Cu, Ni)6Sn5層則會逐漸剝離(spalling)，進而對銲點可靠度造成影響。

關鍵字

SnAgCu ； Ni ； 體積效應

並列摘要

To meet the customer demand on ever smaller portable electronic products, the size of the electronic packages have to become smaller. Consequently, the solder joints in these packages shrink continuously with every new generation of electronic products. As the dimensions of solder joints decrease, the so-called volume effect becomes important. At the present stage, the diameter of solder joints in array-array packages can range from 760μm (BGA joint) to 75μm (Flip-Chip joint). This variation in diameter in fact translates into a 1,000 times difference in volume. Such a large difference in volume produces a pronounced solder volume effect. In this study, the volume effect on the liquid-solid reactions between Sn3AgxCu (x=0.4, 0.5, 0.6, wt. %) solders and Ni is investigated. Three different sizes of solder spheres (760, 500, and 300 μm) were placed on the Ni pads at reacted at 235℃. Two reaction products, (Cu, Ni)6Sn5 and (Ni, Cu)3Sn4, were present at the interface in all the samples. Interestingly, a massive spalling of (Cu, Ni)6Sn5 from the interface occurred, especially in samples with smaller dimension and smaller Cu concentration. We attributed the massive spalling of (Cu, Ni)6Sn5 to the decrease in the amount of available Cu in the solders as the dimension as well as the Cu concentration decreased. The result of this study suggested that a Cu-rich SnAgCu solder should be used to prevent this massive spalling of (Cu, Ni)6Sn5.

並列關鍵字

soldering ； volume effect ； SnAgCu