陶瓷/高分子與陶瓷/玻璃複合材料的微波介電性質

Abstract

由於通訊產業的快速發展，使得人們對於元件的微小化及材料特性的優質化要求日增，用於此用途的微波介電材料便成為研究重點，尤以添加低熔點玻璃使低溫可共燒的微波陶瓷更是焦點。另外，陶瓷/高分子複合材料的微波介電性質也在本文中提及。本研究首先探討陶瓷/高分子異相間體積百分比的改變與其微波特性的關係，分別以熱固性塑膠PVDF為基底相，商用微波陶瓷（HF22K、HF37N、MSZT40S(B)、MBT-40B、MRT45B、HF90HQ）與Al2O3、BaO-La2O3-4TiO2、BaO-La2O3-4.7TiO2、TiO2等陶瓷為分散相製作複合材料，發現前人推論的數個理論模型中，尤以Lichtenecker所建立之公式最能有效預估複合材料的介電常數，但介電損失因子與共振頻率溫度係數方面，則未發現有效可預估之模型。另外，得知陶瓷/高分子複合材料相對介電常數ε與Q值都不高。 本研究第二部份則探討Lichtenecker之公式能否預估低熔點玻璃-陶瓷系統的介電常數。此部份選用商用玻璃（GA9、GP5210、EG3606）為基底相，Al2O3、BaO-La2O3-4TiO2及BaO-La2O3-4.7TiO2陶瓷為分散相，發現如玻璃與陶瓷彼此產生反應，在無法推知新相的產生量下，將無法藉由Lichtenecker公式推算合成的介電常數。

Due to the rapid growth of communications industry using microwave frequencies, such as car telephones and portable phone, has created a demand for the greater miniaturization and better characteristics of components such as band pass filters and local oscillators. Therefore, studying the microwave dielectric materials becomes more and more important. First, this article reports on a study of the microwave dielectric properties of ceramics dispersions in a polymer matrix. Samples investigated in this study are composed of ceramics powders(HF22K, HF37N, MSZT40S(B), MBT40B, MRT45B, HF90HQ, Al2O3, TiO2, BaO-La2O3-4TiO2, and BaO-La2O3-4.7TiO2)randomly dispersed, with a desired volume concentration, in a polymer（PVDF) matrix. The experimental values of dielectric constant are compared to those obtained by using different dielectric constant mixing laws. Only Lichtenecker formula can agree with experiments, but there is no effective model to predict the dielectric loss and the temperature coefficient of resonant frequency . The second part of the study, we discuss the relationship between the dielectric constant of ceramics/glass composite and glass additions. In this part, we use commercial glass (GA9, GP5210, and EG3606) as a matrix and ceramics (Al2O3, BaO-La2O3-4TiO2, and BaO-La2O3-4.7TiO2) as dispersions. If ceramics and glass is reacted, Lichtenecker formula is fail to predict the dielectric constant of the ceramics/glass composite.