Patent ID: 7161461
Filing Date: 2007-01-09
Classification: H01C

Abstract:
1. A method for manufacturing a trim resistor assembly comprising providing a trimmable resistor element comprising a nonconductive substrate, a resistive film disposed on the surface and including a trimmable portion, a first contact pad disposed on the substrate in contact with said resistive film, and a second contact pad disposed on the substrate spaced apart from the first conductive pad and in contact with the resistive film, said substrate comprising an obverse face having a central region and a perimeter region and a reverse face opposite the obverse face; connecting a first lead wire to the first contact pad and a second lead wire to the second pad, thereby forming a pre-assembly; arranging the pre-assembly within a mold, said mold defining a cavity and comprising a pedestal and said pre-assembly being arranged such that the pedestal covers the central region and said perimeter region is exposed within the mold; injecting a polymeric material into the cavity to form a polymeric housing, said polymeric material being injected against the perimeter region of the obverse face and the reverse face of said trimmable resistive element to embed the trimmable resistive element within the polymeric housing, thereby producing an assembly; and removing the assembly from the mold, said removing including withdrawing the pedestal from the polymeric housing to form an opening in the polymeric housing and expose the central region of the substrate.