低溫化銀電極膏製備與高頻應用之研究

Abstract

本論文研究分別以草酸銀和氧化銀做為誘發金屬有機銀鹽類 ( Metallo- Organic Decomposition, MOD ) 的反應劑，以高速混合機及三軸滾輪進行混合及分散等來製備金屬銀膏。銀膏之燒附條件可藉由草酸銀和氧化銀的添加而降低金屬有機銀鹽類產生熱裂解反應 ( Thermal Decomposition Reaction )的溫度，並使金屬有機銀鹽類與添加劑還原形成奈米金屬銀後形成金屬膜。 本研究針對所製備出之金屬膜層進行分析與研究，藉由熱重分析 ( Thermogravimetric analysis, TGA)、熱差分析 ( Differential thermal analysis, DTA) 與 ( Derivative thermogravimetry, DTG)等，探討不同反應劑對金屬有機銀鹽類之熱裂解反應，並藉由掃瞄式電子顯微鏡 ( SEM )分析金屬膜之微結構及燒附現象，透過動態流變儀( Stress and Strain Rheometers ) 量測之黏彈性行為 ( Viscoelasticity ) 探討不同反應劑於膏體中之各項流變特性等。針對其中分布均勻性與觸媒反應特性最好之氧化銀反應劑進行成份及熱裂解反應等深入之探討與研究，找尋出最佳之組合量。研究中更針對高溫、低溫燒附行為之金屬膜層的高頻阻抗特性進行深入研究與比較。並初步完成濾波器元件特性，後續將針對低溫高頻元件進行研究。

In this study, at first, focus on the effect of silver oxalate addition on physical characteristics of metallo-organic-decomposition (MOD) silver screen-printable paste for thick film technology. The addition of silver oxalate in the paste not only produces fresh fine silver particles after curing, but also reduces the decomposition temperature of the lubricant coated on the silver flakes. This is an effective route to provide fine silver particles to the paste without significantly changing the rheological behavior. Then, the next study focus on paste formulations containing silver oxide coated with MOD (metallo-organic decomposition) agent of silver stearate were prepared without the use of any silver powders or silver flakes. The lowest electrical resistivity of 13.2x10-6 □-cm was obtained for the film prepared from paste with the Ag2O/silver stearate ratio of 100:5 at a solid loading of 80wt% in solvent α-terpineol, after being cured at 160□C for 5min, which meets the requirements of low-temperature and high speed manufacturing for practical applications. Co-existence of the Ag2O and silver stearate induces their simultaneous transformation to the silver form at temperatures below 160□C. The electrical properties of silver films, prepared using a low-curing-temperature metallo-organic-decomposition (MOD) paste and a high-temperature silver paste screen-printed on polished and nonpolished alumina substrates, at microwave frequency were characterized in this study. At last, to evaluate RF electrical properties between low-temperature-curing and high-temperature silver paste, multilayered structure and the low-temperature co-fired ceramic technology are employed to design and fabricate the filter.