An Investigation on The Dielectric Properties of Epoxy Filled With Glass Micro-Spheres and Boron Nitride

Abstract

Most semiconductor devices are packaged in epoxy polymer composites to reduce thermal expansion-coefficient. However high thermal conductivity as well as low dielectric fillers are required for high heat output devices in near future for electronic packaging and printed circuit boards as hardened neat epoxy in spite of its good mechanical strength, often cannot satisfy this demand due to its low thermal conductivity. In view of this, in the present work, solid glass micro-sphere (SGM) with Boron Nitride (BN) filled hybrid epoxy composites, with BN content ranging from 0 to 10 vol% in epoxy reinforced with 20 vol% of SGM have been prepared with an objective to study the effect of BN on the dielectric as well as thermal properties of the composites. Dielectric constant measurements are made for these composites using a HIOKI- 3532-50 Hi Tester Elsier Analyzer with an applied Ac voltage of 500mv in the frequency range of 1 kHz to 1 MHz. In our previous study it is also noticed that the thermal conductivity of the composites decreased with increase in SGM content which is not desirable. Thus, in order to obtain relatively high thermal conductivity and low dielectric constant at the same time, fillers like AlN or BN which have high thermal conductivity can be added to the polymer in addition to the SGMs.