Characterization and Comparison of Five SAC-based Solder Pastes for Pb-free Reflow Soldering

Author

Chen, Catherine H. ; Wong, Wallace ; Lo, Jeffery C C ; Song, Fubin ; Lee, S. W Ricky

Author_Institution

Electron. Packaging Lab., Hong Kong Univ. of Sci. & Technol., Hong Kong

fYear

2007

fDate

26-28 June 2007

Firstpage

1

Lastpage

8

Abstract

Based on literature review and industry survey, five types lead-free solder pastes, namely, SAC305 (96.5%Sn-3.0%Ag-0.5%Cu), SAC387 (95.5%Sn-3.8%Ag-0.7%Cu), SACS (96.2%Sn-2.5%Ag-0.8%Cu-0.5%Sb), SCN (99.3%Sn-0.7%Cu-0.05%Ni), and SACC (96.4%Sn-3.0%Ag-0.6%Cu-0.01%Ce) are studied in this paper. The basic properties of selected Pb-free solder pastes are tested based on IPC standards. These tests include solder paste particle size analysis, measurement of melting point, solder balling test, tack test and slump test. The reflow temperature profiles for these five types of solder pastes are set up and surface mount parameters are optimized according to their characteristics. Solder reflows with nitrogen and without nitrogen are performed for comparison. Intermetallic compounds of different solder alloys on both ENIG and OSP pad finishes are investigated. Cross-sectioned samples are inspected by SEM/EDX. The related results of each test are presented.

Keywords

X-ray chemical analysis; antimony alloys; cerium alloys; copper alloys; materials testing; melting point; nickel alloys; particle size; reflow soldering; reliability; scanning electron microscopy; silver alloys; solders; surface mount technology; tin alloys; EDX; ENIG pad finishing; IPC standards; OSP pad finishing; SAC-based solder pastes characterization; SAC305; SAC387; SACC; SACS; SCN; SEM; SnAgCu; SnAgCuCe; SnAgCuSb; SnCuNi; cross-sectioned sample inspection; intermetallic compounds; lead-free reflow soldering; melting point measurement; nitrogen; particle size analysis; reflow temperature profiles; slump test; solder alloys; solder balling test; solder joint reliability data; surface mount parameters; tack test; Electronics packaging; Environmentally friendly manufacturing techniques; Lead; Nitrogen; Particle measurements; Reflow soldering; Scanning electron microscopy; Size measurement; Temperature; Testing;

fLanguage

English

Publisher

ieee

Conference_Titel

High Density packaging and Microsystem Integration, 2007. HDP '07. International Symposium on

Conference_Location

Shanghai

Print_ISBN

1-4244-1252-8

Electronic_ISBN

1-4244-1253-6

Type

conf

DOI

10.1109/HDP.2007.4283549

Filename

4283549