Method for Trimming Polymer Thick Film Resistors on Dielectric on Thermal Conductor Substrates
Original Publication Date: 1986-Dec-01
Included in the Prior Art Database: 2005-Mar-09
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 heat sink 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 the supply design. The aluminum heat sink mentioned above provides a common heat sink for all the resistors as well as the other power-generating elements and eliminates individual heat sinks, thereby reducing system cost. Economic use of DOTC substrates requires use of integral power resistors. Present methods of screening these resistors do not consistently produce resistors of sufficiently low tolerance to attain adequate manufacturing yields.