Dielectric and thermal studies of inorganic microfillers on polymer microwave substrates - metallocene cyclic olefin copolymers (COC)

Metallocene cyclic olefin copolymers (mCOCs) are considered as potential candidates for both optical markets and electric applications because of their high transparency in the visible and near UV regions, and their high electrical resistance. In the microelectronic packaging industries, the propagation velocity of electromagnetic waves on the substrates is inversely proportional to the square root of the dielectric constant. Additionally, extents of energy losses and the elimination of stray electromagnetic radiation are all related to Dk properties. As a result, finding a way to lower Dk values for packaging materials is a trend in high-performance computing devices. This paper investigates the dielectric and thermophysical properties of mCOC by adding to it various proportions of microfillers. Three microfillers, all made up of soda-lime-borosilicate glass, were used in the tests. One of the microfillers was the original glass without surface treatment, while the other two have the methacrylato chromic chloride (MCC) treatment, and epoxy silane treatment, respectively. They were mixed with the melted mCOC and then molded to disks of 30 mm diameter and 1 mm thickness. Thermophysical properties such as the bulk density, heat capacity and thermal conductivity were measured at room temperature to understand the thermal stability and heat transport performance of the composites. Additionally, dielectric properties were measured at room temperature at 1 MHz frequency, in order to evaluate electronic wave transport characteristics and extent of energy loss. (C) 2002 Published by Elsevier Science Ltd.