Evaluation of Cutting Forces for Intermetallic Compounds Formed on Solder Joint Interface by Instrumented Ultramicrotome

Abstract

Observing interface states is especially important in evaluating solder joint reliability. Cross_ section samples of intermetallic compounds generated by copper metallization with lead_ free solders (Sn8Zn3Bi, and Sn9Zn, Sn3Ag0.5Cu), with Sn37Pb as a reference, were prepared using an ultramicrotome. We used an instrumented ultramicrotome to study the cutting force profiles of the intermetallic compounds. When we measured them with a needle_ like diamond knife (60 mm in width), we found peaks in the profiles consisting of two elements that corresponded to those of the intermetallic compounds. These profiles also correlated well with the hardness of the constituent phases at the solder joint interface.

Shear Fracture Behavior on Ball Grid Arrayed Tin–Silver–Copper Solder/Pure Copper Pad Joint Interface

“…Various mechanical and physical properties of Sn-3 mass%Ag-0.5 mass%Cu solder alloy/ electrode on the print board joint have been studied by shear test, pull test, bending test, thermal fatigue test and so on. [9][10][11][12][13][14] Recently, the soldering on pure Cu substrates has been focused and tried because the Under Bump Metallizing (UBM) treatment of electro less Ni-P plating and Au vaporization on pure Cu substrates has been increased the cost of IC device production. 15) Furthermore, Cu cored technique in solder ball has been researched from the aspect of the ball strength and electric conductibility.…”