Additive Trim of Polymer Thick Film Resistors
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
A method is described to accomplish the trim of polymer thick film resistors while maintaining the characteristics of the polyimide substrate. A packaging technology for power supplies, Dielectric on Thermal Conductor (DOTC), uses copper-metallized polyimide as a substrate. The polyimide is adhesively bonded to an aluminum structure which sinks the heat generated by the power dissipating elements of the supply. A large percentage of the heat is generated by the several power resistors required by supply design. A method of producing these resistors is by screen printing polymer paste in the appropriate aspect ratios and thicknesses to produce the correct value of resistance.