先進微電子封裝中錫銀銅銲料與金/鎳表面處理層之界面反應

Interface Reaction between SnAgCu Solders and Au/Ni Surface Finish in the Advanced Microelectronic Packages

羅偉誠(W. C. Luo) ； 蕭麗娟(L. C. Shiau) ； 何政恩(C. E. Ho) ； 高振宏(C. R. Kao)

《界面科學會誌》 26卷2期 (2004/06) Pp. 99-107

https://doi.org/10.30020/JCCIS.200406.0004

摘要

銅濃度的效應對於錫銀銅銲料與墊層間的界面反應扮演著舉足輕重的角色。本研究發現錫銀銅銲料中銅含量的微小差異，會影響迴銲後所產生的介金屬種類與生長形態，也影響銲點的剪力強度。當銲料中沒有銅時（例如使用Sn-3.5Ag），迴銲後在銲點界面處所產生的介金屬是Ni3Sn4。當銅濃度較高時（例如使用Sn-3.5Ag-0.75Cu），所產生的介金屬則是（Cu1-p-qAupNiq）6Sn5。當銅濃度為0.5wt.%（例如使用Sn-4Ag-0.5Cu），則迴銲後Ni3Sn4與（Cu1-p-qAupNiq）6Sn5兩種介金屬都會共同存在於界面，而兩者之間夾雜了一層銲料。再經過固態熱處理後，界面上則產生一層（Cu1-p-qAupNiq）6Sn5與一層（Ni1-yCuy）3Sn4。隨銲料之銅濃度的升高，銲接接合物之生長情形將由原先單一、且連續的（Ni1-yCuy）3Sn4層，逐漸轉變為（Cu1-p-qAupNiq）6Sn5與（Ni1-yCuy）3Sn4之混合型式。若銅的濃度更高時，則銲接接合物將轉變為一連續的（Cu1-p-qAupNiq）6Sn5層。換句話說，隨所採銲料之銅濃度的不同，則界面上之生成物種類與其生長形態亦有所不同。亦即銲料之銅濃度的高低，將可直接影響銲接界面之接合物的種類與生長形態。

關鍵字

界面反應 ； 無鉛銲料 ； 表面處理層 ； 介金屬

並列摘要

The reactions between the SnAgCu lead-free solders of various Cu compositions and the Au/Ni surface finish in advanced electronic packages were studied. The Cu concentration in the SnAgCu ternary solder has a very strong effect on the compound formation and the shear strength in solder joints with the Au/Ni surface finish. After reflow, the solder joints were subjected to aging at 180 oC for time up to 500 hrs. When there was no Cu (Sn-3.5Ag), the reaction product was Ni3Sn4. When the Cu concentration was high (Sn-3.5Ag-0.75Cu), the reaction product was (Cu1-p-qAupNiq)6Sn5 right after reflow, and two intermetallic compounds (Cu1-p-qAupNiq)6Sn5 and (Ni1-yCuy)3Sn4 formed after aging at 180°C for 250 and 500 hrs. When the Cu concentration was 0.5 Wt.% (Sn-4Ag-0.5Cu), both Ni3Sn4 and (Cu1-p-qAupNiq)6Sn5 were present near the interface right after reflow, and there was a layer of solder between these two intermetallic compounds. After aging, a layer of (Cu1-p-qAupNiq)6Sn5 over a layer of (Ni1-yCuy)3Sn4 formed at the interface.

並列關鍵字

surface finishing ； lead-free soldering ； intermetallics ； ball grid array