DESIGN OF AROMATIC COPOLYESTERS FOR USE IN MICROELECTRONIC DEVICES

The next generation of microelectronic devices will require design of new kinds of polymers which are tailored to display a dielectric const ant as low as 2.0, a coefficient of thermal expansion (CTE) which matc hes the metal circuitry as well as the silicon substrate, moisture and chemical resistance, and dimensional stability at processing temperat ures of 300-400 degrees C which are required to form an adhesive bond between laminates. In our program, we have made significant progress i n all of these areas through the use of liquid crystalline copolyester s (LCP's) laminated with a newly developed crosslinkable copolyester. In this paper, data are presented which illustrate how films and coati ngs of either system can be made to adhere in the solid state by inter chain transesterification reactions (ITR) at the interface. Ability to foam the crosslinkable copolyester films provides direct control over the dielectric constant. The effect of pore size and distribution on the dielectric constant will be discussed. The potential to dramatical ly increase the melting point of the LCP's through high temperature an nealing is also discussed.