An Evaluation Method for Tensile Characteristics of Cu/Sn IMCs Using Miniature Composite Solder Specimen

Abstract

In design of electronic packages, finite-element method (FEM) analysis for evaluating the strength and reliability of solder joints should be conducted with consideration of the presence of Cu/Sn intermetallic compounds (IMCs) generated at the interface between solder and copper wiring. To conduct such analysis accurately, the deformation characteristics of Cu/Sn IMCs must be clarified by conducting tensile tests. This paper describes a method to evaluate tensile characteristics of Cu/Sn IMCs. The method employs a composite specimen with first outer layer of Cu, second layer of Cu/Sn IMCs, and core of Sn-3.0Ag-0.5Cu lead-free solder. The specimen is made by a method in which a copper-plated solder specimen is heat treated at 453 K to generate Cu/Sn IMCs between the solder and copper. Tensile tests were conducted using the composite specimen. After the tests, the fracture appearance and characteristics of the stress-strain relations of the specimens were investigated. Based on the results, a numerical method based on the rule of mixtures (ROM) is proposed to estimate the stress-strain relation of Cu/Sn IMCs under tensile loading.

Material property control of CuSn alloy using wire and arc additive manufacturing (Translated)

“…The growth of crystal grains and the precipitation/decomposition of IMCs due to this thermal history have a significant influence on the Young's modulus. In particular, the Young's modulus of the ε-phase is higher (130 GPa) than that of the α-phase (Ohguchi and Kurosawa, 2016). The higher Sn content may be partly responsible for the increased proportion of IMCs.…”

A study on the sandwich-style notched tensile specimens for different materials through a simulation analysis

“…Thus, the study is concerned with tensile strength with the properties of CFRP, a composite material that draws attention for its excellent durability and lightness, and stainless steel and aluminum, the widely used metals, and is designed to acquire the data for future researches on the fracture characteristics and durability of heterogeneous materials and various composite materials. We believe that the data obtained from the specific researches will serve as the basic data for researches on composite materials like CFRP and other different materials [6][7][8][9][10].…”