Mechanical properties of interfacial phases between Sn-3.5 Ag solder and Ni-18 at. % W barrier film by nanoindentation

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<jats:title content-type="abstract-heading">Purpose</jats:title>
<jats:p> – The purpose of this paper is to investigate the hardness and elastic modulus on interfacial phases formed between Sn-3.5Ag solder and Ni-18 at. % W alloy film by nanoindentation. It has been found that a ternary amorphous Sn-Ni-W layer formed below Ni3Sn4 IMC at the interface. In this study, mechanical properties of the IMC formed between SA solder and Ni-18 at. % W film after six times reflows were performed by nanoindentation. </jats:p>
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<jats:title content-type="abstract-heading">Design/methodology/approach</jats:title>
<jats:p> – The characterization was carried at 25°C, and 100 indents were generated. The elastic modulus and hardness were investigated. </jats:p>
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<jats:title content-type="abstract-heading">Findings</jats:title>
<jats:p> – The results showed that hardness of Ni3Sn4 IMC was higher than amorphous Sn-Ni-W phase. A slight bigger indent was observed on the Sn-Ni-W layer compared with that on the Ni3Sn4 IMC. Lower topographical height in the Sn-Ni-W layer indicated that the Sn-Ni-W phase was softer compared with the Ni3Sn4 IMC. The lower hardness and soft Sn-Ni-W phase is significantly related to the amorphous structure that formed through solid-state amorphization. </jats:p>
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<jats:title content-type="abstract-heading">Originality/value</jats:title>
<jats:p> – There are no publications about the indentation on the interfacial between the Ni-W layer and the Sn-Ag solder.</jats:p>
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