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

作者:鄭秀鳳(國立臺灣師範大學物理學系)

摘要：

本研究乃應用複阻抗方法分離出半導電。鈦酸鍶鋇陶瓷的界面電阻（晶界電阻與電極陶瓷接點電阻的和）與晶粒電阻。在居理溫度時，界面電阻聚增，但晶粒電阻則否。
在樣品受到數次的加熱與冷卻循環果成之後，含低液相助燒結劑AST(Al₂O₃-SiO₂-TiO₂)，且具大晶粒之樣品呈現遲滯(hysteresis)。此乃歸因於在居里溫度相變點時，由於大晶粒中發生強大的彈性應變，阻止晶體發生相變所造成的遲滯現象。
在熱循環之初，樣品之界面電阻改變較大，但在數個循環之後，界面電阻則趨於穩定。就對熱循環的阻抗來說，電極材料鋁膠最穩定，銀膠則最差。其中鋁膠與無電鍍鎳與半導電鈦酸鍶鋇電子陶瓷之間的接觸電阻屬歐姆性，而銀膠與無電鍍銅的電極陶瓷間接觸電阻分別約為1000歐姆與550歐姆。。

關鍵詞：正電阻溫度係數、鈦酸鍶鋇、無電鍍、界面電阻　

《詳全文》

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