The Study of Interface Electrical Behavior of Contact Between Electroless Plating and Electroceramics

Author: Hsiu-Fung Cheng(Department of Physics, National Taiwan Normal University)

Abstract：

Complex impedance technique is successfully applied to separate the grain resistance from the interface resistance, which is the summation of grain boundary resistance and electrode-ceramics contact resistance, of the semiconducting (Sr_0.2Ba_0.8)TiO₃:Sb³⁺ ceramics. The fromer does not vary appreciably with temperature, while the latter increases abruptly at Curie temperature. The contact resistance (r_c)of Al-paste and electroless Ni is approximately ohmic and that of Ag-paste and electroless Cu is estimated to be r_c= 1000 and 550 , respectively.
Hysteresis between heating and cooling cycles is observed for the inter-face resistance-temperature characteristics of large granular structure sam-ples, which contain smaller amount of Al₂O₃-SiO₂-TiO₂(AST) sintering aids. Thermal cycling is observed to modify the interfacial resistance significantly at the beginning, but it will reach a stable value after only a few cycles. Al-paste is the most stable electrode material when the resistance to ther-mal cycling is of concern, while the Ag-paste is the worst one.

Keywords：PTCR, (Sr,Ba)TiO3, Electroless Plating

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