要製作內埋式電容，首先必須要有可以印刷塗佈之高介電材料。大部分研究者都是將市售的高介電陶瓷粉末研磨並作表面改質後，再與基板粘著用的環氧樹酯混成塗料。因為混成物之介電常數與所添加高介電陶瓷量成正比，所以要製備出高介電混成材料之關鍵在於達到高陶瓷比，但仍舊可以印刷或塗佈方法粘著成膜。市售的電容陶瓷粉末研磨後大小不易均勻。不均勻的粉體在樹酯中分散性不好，無法製作出高陶瓷比的塗料。我們認為假若有大小均一之奈米粒子，才可以降低樹酯需要量而將高介電陶瓷以分散成可成膜之塗料。為了測試此一假設，我們先開發出一種方法，可以合成出80~300 nm 三種大小而粒徑均一的鈦酸鋇粉體。然後將之均勻分散在含有溶劑之環氧樹酯中，期望製作出合成出粘著牢固之高介電薄膜。 ABSTRACT Ultra-fine BaTiO3 powders were synthesized from the hydrothermal reaction of Ba(OH)2 and freshly prepared titanium hydroxide at less than 100oC. By controlling the size of the titanium hydroxide, narrowly distributed BaTiO3 particles with size of 80nm, 200nm or 300nm, reapectively, were prepared. XRD analysis suggested that the particles are cubic BaTiO3 crystalline with about 80 nm in domain size. The so produced powders were modified with silane and re-dispersed in epoxy resin to prepare composite films and disks and cured at 170oC. For composite disks that contain more than 70vol% ceramics, dielectric constant higher than 100 could be achieved, and increased with decreasing particle size. The value was doubled if the powder contained 10% Pb. Silane modification showed a negative effect on the dielectric constant. More resin (50vo%) had to be used to make a well-adhered film via spin coating. The dielectric constant of the cured film was only ~40, which may be improved if a different coating technique is applied.
