低介電常數與低消散因子聚苯醚之製備與鑑定

Abstract

近年來，在無線通訊設備的使用上，更強的數據傳輸能力和更快的數據傳輸速度被人們所需求。在下一代的訊息傳輸系統，電子訊號的頻率已經增長到了GHz。對於需要如此高頻的應用，我們需要使用低介電常數和低消散因子的材料。聚苯醚系列材料是一種被廣泛使用的工程塑膠，因其具有良好的機械性質和熱性質。同時，在高頻應用中他也具有非常出色的電氣性質。然而，聚苯醚對覆銅基板的黏著力不佳，並且其在工業應用上的熱性質及機械性質還需要提高。 在論文的第一部份中，我們使用氧化聚合的方式去聚合鄰位烷基苯酚。通過使用較為大體積胺作為配位基，我們可以合成高分子量的聚鄰位烷基苯醚，且其可以直接與交聯劑反應。所製備的高分子具有較好的熱穩定性，其熱裂解溫度均在360 oC以上；並且，其具有較低的加工操作溫度，低於180 oC。此三種高分子，都存在半結晶性的結構。隨著側鏈烷基長度增加，高分子的Td 和 Tg 都會降低。但具有更長側鏈烷基的高分子，展現出較好的半結晶性結構。在10 GHz的條件下，聚鄰甲基苯酚的Dk值為2.61且其Df值為0.00429。高分子中存在殘留的銅離子，會導致介電常數和消散因子較高，因此需加強純化程序，以為工業應用。 在論文的第二部份中，我們改質商品化的聚苯醚寡聚物，引入羥基或羧基來提高介電材料對基材的黏著力。由基於OPE改質材料製備所得薄膜皆具有良好的熱穩定性及電性質。 OPE和GPH系列膜列熱解溫度分別高於300 oC及380 oC。隨著GPH系列高分子中羥基含量的減少及交聯膜中橡膠含量的增加，介電常數及消散因子都得到降低。GPH系列最佳膜具有最低的介電常數值為2.48， 最低消散因子值為0.0082，可應用於高頻印刷電路板。

Large capacity and high transmission speed are required in wireless communication devices in recent years. The frequency of electrical signals has reached the GHz bands for the next generation communication system. For such high frequency applications, materials with a low dielectric and a low dissipation factor are needed. Poly (phenylene ether)(PPE) is one of the widely used engineering materials for its good mechanical and thermal properties. It also shows excellent electric properties for using in high frequency applications. However, PPE has a poor adhesion to copper foil and their thermal and mechanical properties need to be improved for industrial applications. In the first part of this thesis, we used oxidative polymerization to polymerize o-alkylphenylene. By using bulky amines as ligand, we could synthesize high molecular weight poly (o-alkylphenylene) and it could directly react with a crosslinking agent. The prepared materials exhibited a high thermal stability with Td above 360 oC, and a low processing temperature lower than 180 oC. All of the three polymers showed semicrystalline structures. With the increased length of the alkyl chain, both Td and Tg were decreased. The Dk and Dk values of poly (2-methylphenylene ether) were 2.61 and 0.00429 at 10 GHz. The Cu2+ ion residue would lead to a higher Dk and Df value, thus purification on the prepared materials would be important for practical applications. In the second part of the thesis, we modify the commercial oligo (phenylene ether)-styrene end-functionalized materials (OPE-2st) with hydroxyl or carboxyl groups to improve the adhesion of the dielectric materials to the substrates. The films prepared from OPE modified materials all showed good thermal stability and electric properties. OPE and GPH based films had Td values higher than 300 oC and 380 oC, respectively. With the decreased hydroxyl content in GPH and the increased rubber composition in the cured films, both the Dk and Df values were reduced. The optimum GPH based films had the lowest Dk of 2.48 and Df of 0.00825 at 10 GHz, which could have potential applications for high frequency print circuit boards.