Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403


공학

한국표면공학회지 (48권6호 253-259)

A Study on Characteristics of the Ni-Pd Alloy Electroplating

Ni-Pd 합금 전해도금의 특성에 관한 연구

조은상;정대곤;조진기;
Cho, Eun-Sang;Jung, Dae-Gon;Cho, Jin-Ki;

한국산업기술대학교 신소재공학과;
Department of Advanced Materials Engineering, Korea Polytechnic University;

DOI : 10.5695/JKISE.2015.48.6.253

Abstract

The test equipment becomes more important with the development of semiconductor industry. MEMS probe is an important testing component to detect the defects from the generated electric signal when it contacts the metal pad of semiconductor devices. Ni-Pd alloy has been paid attention to as a candidate of MEMS probe material because of its high surface hardness and relatively low resistivity. In this study, electroplated Ni-Pd alloy has been prepared by using ethylene diamine as a complexing agent. Solid solution alloy coating could be formed when concentration of palladium chloride and current density were in the ranges of 1~5 mM and $0.2{sim}1.5A/dm^2$, respectively. The increase of current density brought about an decrease in palladium content, which made both of lattice parameter and grain size smaller. As a result of grain refinement, high hardness could be obtained. However, surface cracking was observed due to residual stress when the current density was above $1.3A/dm^2$. When effects of heat treatment temperature on hardness and sheet resistance were investigated, the accompanied grain growth decreased both of them. The decrease of hardness remained stable at a temperature of $200^{circ}C$. The sheet resistance was drastically reduced at $100^{circ}C$. After that, it was found to become constant.

Keywords

Nickel-Palladium Alloy;Electroplating;Hardness;X-ray diffraction;Lattice parameter;Heat treatment;Sheet resistance;