Effects of Sintering Process on the Dielectric Properties of BME-Y5V-MLCCs
碩士 === 國立臺北科技大學 === 材料及資源工程系研究所 === 97 === The technology of MLCCs fabricated by tape casting process had become mature. Most MLCCs were made toward smaller size and higher capacitance for market demand. In the result, more layer numbers and lower tape thickness of MLCCs were developed activity. Nob...
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| Format: | Others |
| Language: | zh-TW |
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2009
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| Online Access: | http://ndltd.ncl.edu.tw/handle/46j24x |
| Summary: | 碩士 === 國立臺北科技大學 === 材料及資源工程系研究所 === 97 === The technology of MLCCs fabricated by tape casting process had become mature. Most MLCCs were made toward smaller size and higher capacitance for market demand. In the result, more layer numbers and lower tape thickness of MLCCs were developed activity. Noble metal electrode (NME) using Ag-Pd metals cost more than base metal electrode (BME) using Cu-Ni metals, but BME-MLCCs had lower capacitance due to inner electrode-nickel oxided easily in high temperature. BME-MLCCs must be fired in reducing atmosphere to prevent the oxidation of nickel .
This research focused on effects of BME-Y5V-MLCCs by changing sintering process. A flat curve was invesgated on the temperature of coefficient capacitance (TCC) as sintering temperature was higher (above 1223oC) or soaking time was longer (over 2h) at 1220oC. After grain sizes of ceramics in MLCC calculated, we found grain size in multi-layer ceramic bulk was larger than MLCCs. Second phase Ba2TiSi2O8 and liquid phase sintering invesgated in XRD data and SEM image. We also found the chemical mechanism of second phase and liquid phase. According to the result of dilatometer examination, the initial shrinkage temperature of nickel electode mixed with Y5V ceramic powder was lower than raw Y5V ceramic powder. The nickel oxide peaks were found in the XRD data. It’s should be produced in the re-oxidation stage of sintering process.
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