Three zone-reactive wetting ring structure at interface between lead-free Sn-Ag-Cu solder and Ni pad

Author

Xiaoqing, Li ; Fai, Lam Tim

Author_Institution

Spansion (China) Ltd., Suzhou, China

fYear

2009

fDate

6-10 July 2009

Firstpage

224

Lastpage

227

Abstract

The wetting behavior of Sn-Ag-Cu solder ball on nickel pad has been studied. SEM and EDX were employed to analyze the solder joint interfacial microstructure. Three zone-reactive wetting ring structure was found at the interface. To further study this kind of structures, solder ball attachment (SBA) and surface mount technology (SMT) were performed to prepare more samples. Experimental results show that the reactive wetting ring is a characteristic of wetting behavior of Sn-Ag-Cu solder ball on Ni or Cu pad. It forms in ball attach reflow and sometimes can remain after SMT. A model was proposed to illustrate the three zone structure. Effects of the reactive wetting ring on the joint adhesion quality are discussed in this paper.

Keywords

X-ray chemical analysis; adhesion; chemical interdiffusion; copper; copper alloys; interface structure; nickel; reflow soldering; scanning electron microscopy; silver alloys; solders; surface mount technology; tin alloys; wetting; Cu; EDX; Ni; SEM; SnAgCu-Ni; adhesion; ball attach reflow; intermetallic compounds; older ball attachment; solder ball-nickel pad interface; solder joint interfacial microstructure; surface mount technology; three zone-reactive wetting ring structure; Adhesives; Copper; Environmentally friendly manufacturing techniques; Intermetallic; Lead; Microstructure; Nickel; Optical microscopy; Soldering; Surface-mount technology;

fLanguage

English

Publisher

ieee

Conference_Titel

Physical and Failure Analysis of Integrated Circuits, 2009. IPFA 2009. 16th IEEE International Symposium on the

Conference_Location

Suzhou, Jiangsu

ISSN

1946-1542

Print_ISBN

978-1-4244-3911-9

Electronic_ISBN

1946-1542

Type

conf

DOI

10.1109/IPFA.2009.5232663

Filename

5232663