Intermetallic Reaction of Indium and Silver in an Electroplating Process

Abstract

The reaction of indium (In) and silver (Ag) during the electroplating process of indium over a thick silver layer was investigated. It was found that the plated In atoms react with Ag to form AgIn 2 intermetallic compounds at room temperature. Indium is commonly used in the electronics industry to bond delicate devices due to its low yield strength and low melting temperature. In this study, copper (Cu) substrates were electroplated with a 60-lm-thick Ag layer, followed by electroplating an In layer with a thickness of 5 lm or 10 lm, at room temperature. To investigate the chemical reaction between In and Ag, the microstructure and composition on the surface and the cross section of samples were observed by scanning electron microscopy (SEM) with energydispersive x-ray spectroscopy (EDX). The x-ray diffraction method (XRD) was also employed for phase identification. It was clear that indium atoms reacted with underlying Ag to form AgIn 2 during the plating process. After the sample was stored at room temperature in air for 1 day, AgIn 2 grew to 5 lm in thickness. With longer storage time, AgIn 2 continued to grow until all indium atoms were consumed. The indium layer, thus, disappeared and could barely be detected by XRD.

Rational Design of Ag‐Based Catalysts for the Electrochemical CO2 Reduction to CO: A Review

“…[70,74] Amongm any availablem etal electrodes, In exhibits relatively low catalytic activityf or the HER due to its high overpotential. [127][128][129] Moreover,i ti sr eported that Ag and In are easily miscible with each other to form corresponding intermetallic compounds (IMCs), [130][131][132][133] resulting in more prominent properties and therefore more fascinating catalytic capabilities, such as breaking the linear relationshipso fB Es by doping pblock element In into d-block element Ag. Based on above considerations, in addition to Ag-Cu alloys, Ag-In bimetallic NPs as catalysts have also been widely reported in the selective ECR to CO with the hope to enhancing the catalytic properties of Ag NPs.…”

“…[69,77,78] Indeed, in addition to polycrystalline and single-crystalline Ag, some new At ypes have been developed and characterized recently,s uch as nanostructured Ag with different sizes, [79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94] supported Ag catalysts with different substrates including C, TiO 2 ,A l 2 O 3 , [95][96][97] dopant-aided Ag, [98-120, 129, 130] oxide-derived Ag, [121][122][123][124][125][126][127][128] and surface-modified Ag. [131][132][133][134] In principle, the reduction of NP size can enhancet he surface reactivity of nanomaterials by either directly affecting the atomic arrangement, such as ratio of the atoms at the edge, corner, or surface, or amplifying the effects of other structural factors such as defects, resulting in the tuning of BEs of intermediates and transition states on catalyst surfaces. [56,80,49,56] In fact, size effects have been frequently reported in the ECR to CO by theoretical and experimental studies.…”

The Strength of High-Temperature Ag–In Joints Produced Between Copper by Fluxless Low-Temperature Processes

“…We started with In layer thickness of 8 lm, which is thus designated as the first design. When In is plated over Ag, it reacts with Ag to form AgIn 2 compound even at room temperature [17][18][19]. According to the Ag-In phase diagram in Fig.…”

Stable interconnections for LTCC micro-heater using isothermal solidification technique

“…The equilibrium phase diagram of the Ag-In binary system consists of seven equilibrium phases, including AgIn 2 . Wang et al (2009) is reported that AgIn 2 forms at room temperature. Roy and Sen (1991) observed the gradual transformation of ε-AgIn 2 phase into δ-Ag 2 In phase for silver-rich films because of indium diffusion through silver grain boundaries.…”