| Summary: | 碩士 === 國立高雄第一科技大學 === 機械與自動化工程所 === 93 === ABSTRACT
This research investigates the copper thin film termination electrode of multi-layer ceramic capacitor (MLCC) prepared by using DC magnetron sputtering. The substrates are barium titanates (BaTiO3) MLCC, which possess the Class II-X7R specification. The experimental design adopts the central composite design (CCD) to carry out the sputtering and annealing parameters. The adhesion, thickness and resistivity of Cu termination are measured to evaluate the reliability between Cu thin film and substrate. The comparison of the termination electrodes of MLCC prepared by either sputtering or dipping is also made. The purpose of the experiment is to improve the defects, produced by dipping technique through the sputtering technology. The improvement of Cu termination electrodes results in better surface smoothness, excellent plating layer and solderability, making Cu thin film applicable to MLCC termination electrode.
The experimental results show that the resistivity of Cu termination electrode decreases after annealing. The long-term annealing at high temperature in air atmosphere may leads to the partial decomposition of barium titanates, resulting in the occurrence of TiO2 on the surface of BaTiO3. Moreover, the formation of Cu2O is due to partial oxidation of Cu when annealing in air conditions. The loose structure between Cu2O and TiO2 reduces the adhesion of Cu electrode and barium titanates (BaTiO3) dielectric. The Cu thin film termination electrode well attaches to the inner electrode. After electroplating, the excellent Ni and Sn plating layers are obtained due to the better smoothness of Cu termination. The MLCC with Cu thin film termination electrode has a lower dissipation factor(D.F), Its average value is 1.41E-02 or Tanδof loss angle is 0.8078, but dissipation factor of average value is 1.79E-02 or Tanδof loss angle is 1.025 using dipping Cu thick film. The soldering adhesion and pull strength can meet the MLCC standard specification. The experiment proves the feasibility of copper thin film termination electrode of MLCC by using sputtering technique.
Keyword: MLCC, sputtering, dipping, dissipation factor
|
|---|
