Processing MLCC with Copper End Terminations

摘要

Copper End Terminations have become widely integrated into the production processes of MLCC manufacturers. Many process variables must be controlled to provide similar results to the well known silver terminations. The single largest change is the use of a nitrogen atmosphere in the firing process. Due to the nature of this firing atmosphere, modifications have been made to traditional termination formulations. Typical copper termination pastes consist of copper powder, glass powder, and an organic vehicle system. The greatest obstacle of the vehicle system is to leave no carbonaceous residue after firing in nitrogen. In order to make the vehicle systems compatible in the reducing atmosphere; the use of oxygen dopants may be required. These vehicle systems behave differently from traditional vehicles during application, requiring modified processing parameters. This paper will review experimentation performed to evaluate the processing of copper end termination materials. Processing steps to be examined are: dipping profile, drying profile, and firing profile as well as variations of the oxygen content in the burn out zone and peak firing temperature. Through the use of electrical, microstructural and mechanical analysis, each of these variables will be evaluated and discussed.