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1. Introduction
High-temperature sintering silver paste finds extensive application in discrete electronic components like thermistors, varistors, multi-layer ceramic capacitors and multi-layer ceramic inductors. When contrasted with base metal system such as nickel and copper, the exceptional attributes of silver paste, its unparalleled conductively, reduced equivalent series resistance and elevated resonant frequency remain indispensable to fulfill the evolving requirements of high-power and high-frequency electronic advancements (Harris, 1998; Yin et al., 2010; Komoda et al., 2012). However, it is widely recognized that the functionality of components can be degraded because of various interactions between electrodes and the active layer. Zou et al. (2021) undertook the optimization of a CuO-doped silver paste to increase adhesion strength on AlN ceramic substrate. On the other hand, co-firing process sometimes yields adverse effects on performance because of physical mismatches, bonding energies or other thermodynamic factors. Instances include cracks generation in multi-layer ceramic capacitors and delamination in integrated circuits (Smith et al., 2008; Zhang et al., 2011). Consequently, the co-firing and sintering behaviors of pastes have garnered significant attention, involving sintering conditions, substrates, conductive pastes, particle sizes and doping materials (Wang et al., 2007; Shih et al., 2024; Yonezawa et al., 2008).
Recently, to address joint attachment and enhance the bonding of silver paste, transient liquid phase sintering (TLPS) or solid–liquid inter-diffusion bonding techniques have gained prominence (Jung et al., 2018; Yang et al., 2016). In the sintering process, the filler metal undergoes melting at the bonding temperature, leading to the formation a liquid phase. Consequently, the constituents of the filler metal permeate the base material, establishing a solid–liquid inter-diffusion interface. Tin has been used as a filler metal to enhance the bonding strength of silver paste, because of its low melting point (as low as 235°C) and comparable ionic radius to silver. Huang et al. (2022) reported TLPS Ag-Sn alloy joints exhibited improved shear strength in comparison to conventional techniques. However, it is widely recognized that intermetallic compounds (IMCs) are commonly generated within solid solution composite systems. This stems from the transient liquid Sn phase at melting point or attachment temperature diffusing into a higher melting point Ag matrix, which remains in a solid state. Consequently, this leads to the formation...