Low temperature brazing of chip inductors by abnormal glow discharge plasma

Abstract

A novel method, by which Cu was deposited on ferrite ceramics with arc-added glow discharge as a precursory procedure and then brazing the ferrite ceramics with vacuum glow discharge, was investigated. This new method can effectively suppress interfacial diffusion and brazing joint oxidation as well as maintain good adhesion in the joint due to low deposition and brazing temperature, the vacuum atmosphere effect, and the cathode sputter-cleaning action of the abnormal glow discharge plasma. The influence of the brazing process parameters on electrical and magnetic properties of the chip inductors is discussed. The optimal deposition and brazing process parameters are presented. Scanning electron microscope line scanning confirms the brazing electrode joints and detected the interfacial diffusion between the joints and the ferrite ceramics