Fabrication of an insulated metal substrate (IMS), having an insulating layer with a high dielectric constant

A copper-based insulated metal substrate (IMS) having an insulating layer with a high dielectric constant has been developed, using an epoxy compound filled with barium titanate filler. A wide variety of polymers and inorganic filters as well as coupling agents were tested for their ability to be fabricated into an insulating layer having a dielectric constant of 26 and a dielectric loss of 0.04 at 400 MHz. The temperature dependence of the cured dielectric was also studied. This copper-based IMS easily allowed for the addition of solder through holes. Reduction in the size of the microstrip line in an UHF power amplifier was attempted. An area less than 1/3 the original size of the conventional glass epoxy printed circuit is expected with this IMS. >