DocumentCode :
1373795
Title :
Sn–Ag–Cu Soldering Reliability as Influenced by Process Atmosphere
Author :
Baated, Alongheng ; Jiang, Junxiang ; Kim, Keun-Soo ; Suganuma, Katsuaki ; Huang, Sharon ; Jurcik, Benjamin ; Nozawa, Shigeyoshi ; Ueshima, Minoru
Author_Institution :
Inst. of Sci. & Ind. Res., Osaka Univ., Ibaraki, Japan
Volume :
33
Issue :
1
fYear :
2010
Firstpage :
38
Lastpage :
43
Abstract :
To develop an optimal surface mount reflow soldering process with Sn-Ag-Cu, the influences of atmosphere and cooling speed on soldering reliability have been examined by using Sn plated chip components and of Pd plated small outline packages (SOPs) on a printed circuit board (PCB). Typical three Sn-Ag-Cu alloy pastes, i.e., Sn-3.0wt%Ag-0.5wt%Cu, Sn-3.8wt%Ag-0.75wt%Cu, and Sn-4.0wt%Ag-0.9wt%Cu, were used for reflow soldering in air or N2 atmospheres. In the case of chip component joints, the solder compositions, cooling speed, and atmospheres during reflow treatment slightly affect the dendritic microstructure of the solder fillets. In contrast, these parameters rarely affect the solder wettability both on boards/components and shear strengths of the solder joints. In the case of the SOP joints, however, the atmospheres in reflow treatment and the fluxes strongly affect the appearances of solder fillet surfaces structure. Despite the types of solder fluxes, N2 process atmosphere obviously improved wettability of the solders on the lead-frames of the SOP. Moreover, the scatter in shear strengths becomes smaller and the wetting of solders on the lead-frames becomes stabler in N2 atmosphere than in air atmosphere.
Keywords :
copper alloys; filler metals; printed circuit manufacture; reflow soldering; reliability; silver alloys; surface mount technology; thermal management (packaging); tin alloys; wetting; SnAgCu; chip component joints; chip components; cooling speed; dendritic microstructure; optimal surface mount reflow soldering process; printed circuit board; process atmosphere; shear strengths; small outline packages; solder fillets; solder fluxes; solder wettability; soldering reliability; Atmosphere; reliability; soldering; thermal fatigue test (TFT); wetting behavior;
fLanguage :
English
Journal_Title :
Electronics Packaging Manufacturing, IEEE Transactions on
Publisher :
ieee
ISSN :
1521-334X
Type :
jour
DOI :
10.1109/TEPM.2009.2035442
Filename :
5371826
Link To Document :
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