Formation and growth mechanism of thin Cu₆Sn₅ films in Sn/Cu and Sn-0.1AlN/Cu structures using laser heating

Abstract

Purpose

The purpose of this study is the formation and growth of nanoscale intermetallic compounds (IMCs) when laser is used as a heat source to form solder joints.

Design/methodology/approach

This study investigates the Sn/Cu and Sn-0.1AlN/Cu structure using laser soldering under different laser power: (200, 225 and 250 W) and heating time: (2, 3 and 4 s).

Findings

The results show clearly that the formation of nano-Cu₆Sn₅ films is feasible in the laser heating (200 W and 2 s) with Sn/Cu and Sn-0.1AlN/Cu system. The nano-Cu₆Sn₅ films with thickness of 500 nm and grains with 700 nm are generally parallel to the Cu surface with Sn-0.1AlN. Both IMC films thickness of Sn/Cu and Sn-0.1AlN/Cu solder joints gradually increased from 524.2 to 2025.8 nm as the laser heating time and the laser power extended. Nevertheless, doping AlN nanoparticles can slow down the growth rate of Cu₆Sn₅ films in Sn solder joints due to its adsorption.

Originality/value

The formation of nano-Cu₆Sn₅ films using laser heating can provide a new method for nanofilm development to realize the metallurgical interconnection in electronic packaging.

Citation

Liang, Z. (2024), "Formation and growth mechanism of thin Cu₆Sn₅ films in Sn/Cu and Sn-0.1AlN/Cu structures using laser heating", Soldering & Surface Mount Technology, Vol. 36 No. 5, pp. 268-275. https://doi.org/10.1108/SSMT-05-2023-0021