Electrodeposition of Ni-B Alloy Film: Effect of Current Density and Heat Treatment on Micro-Mechanical Property

Ni-B alloy films are prepared by electrodeposition with a Watt's bath-based electrolyte. The B content decreases from 14.3 at% to 2.8 at% as the current density increases from 1 A dm(-2 )to 4 A dm(-2). For applications in miniaturized electronics, the micro-scale mechanical property is evaluated by micro-compression test using micro-pillar type specimens. As-deposited Ni-B alloy films exhibit high mechanical strengths and ductility. The Ni-B alloy films are heat treated to evaluate the thermal stability. After the heat treatment, strengthening and formation of an intermetallic compound, Ni3B, are confirmed. The deformation behavior of the micro-pillars changes from ductile to brittle after the 250 degrees C heat treatment, and the compressive strength of the Ni-B alloy film having the B content of 2.8 at% reaches 5.52 GPa due to the precipitation strengthening mechanism by the Ni3B. (C) 2022 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.