ISSN: 0090-3973
Published Online: 27 May 2008
Page Count: 8

Solderability Testing of Lead-Free Solder Joints Using Miniature Specimens
Rosenthal, Y.
PhD student at the Materials Engineering Dept., Nuclear Research Center Negev,

Sabag, O.
Nuclear Research Center Negev,

Tourgeman, A.
Nuclear Research Center Negev,

Zalkind, S.
Nuclear Research Center Negev,

Stern, A.
Materials Engineering Dept., Ben-Gurion University,

Eliezer, D.
Materials Engineering Dept., Ben-Gurion University,

(Received 15 August 2007; accepted 15 April 2008)

Abstract

A new method for mechanical testing of lead-free solder joints solderability is presented. Copper blanks are soldered with a known thermal cycle. Miniature tensile solder joints specimens are produced in large numbers from the blanks having a gage section made of lead-free solder alloy with dimensions that represent actual solder joints. Mechanical properties of Sn-3.5Ag-0.7Cu in tension at room temperature and strain-rates between 2.8×10⁻⁴–2.7×10⁻¹s⁻¹ have been studied. It is concluded that the solder section of the miniature joints is the weakest link in this complex structure. It was also found that the experimental results for solder strength and strain-rate sensitivity are in partial agreement with data obtained using solder bulk specimens. The role of microstructure across the joint, especially intermetallic compounds along the copper/solder interface is also discussed.

Keywords:
solder lead-free alloys, mechanical testing, mechanical properties, miniature tensile specimens, solder joints, intermetallic compounds

Paper ID: JTE101388
DOI: 10.1520/JTE101388
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