A circuit interrupter comprising: a housing comprising a molded case made of liquid crystal polymer; separable contacts disposed within said housing; an operating mechanism disposed within said housing and being structured to open and close said separable contacts; and a trip mechanism disposed within said housing and being structured to cooperate with said operating mechanism to trip open said separable contacts, said trip mechanism comprising an electronic trip circuit and a rigid, conductive mounting base providing a ground to said electronic trip circuit, wherein said rigid, conductive mounting base is insert molded to a portion of said molded case; characterised in that said rigid, conductive mounting base includes a planar portion disposed adjacent said molded case, said planar portion including a plurality of openings, said molded case including a plurality of protrusions disposed through said plurality of openings, in order to mechanically interlock said planar portion to said molded case when said rigid, conductive mounting base is insert molded to the portion of said molded case; and in that said rigid, conductive mounting base further includes two side portions normal to said planar portion, said two side portions being disposed adjacent said molded case, each of said two side portions including a plurality of openings, said molded case including a plurality of protrusions disposed through the plurality of openings of each of said two side portions, in order to mechanically interlock said two side portions to said molded case when said rigid, conductive mounting base is insert molded to said molded case. a housing comprising a molded case made of liquid crystal polymer; separable contacts disposed within said housing; an operating mechanism disposed within said housing and being structured to open and close said separable contacts; and a trip mechanism disposed within said housing and being structured to cooperate with said operating mechanism to trip open said separable contacts, said trip mechanism comprising an electronic trip circuit and a rigid, conductive mounting base providing a ground to said electronic trip circuit, wherein said rigid, conductive mounting base is insert molded to a portion of said molded case; characterised in that said rigid, conductive mounting base includes a planar portion disposed adjacent said molded case, said planar portion including a plurality of openings, said molded case including a plurality of protrusions disposed through said plurality of openings, in order to mechanically interlock said planar portion to said molded case when said rigid, conductive mounting base is insert molded to the portion of said molded case; and in that said rigid, conductive mounting base further includes two side portions normal to said planar portion, said two side portions being disposed adjacent said molded case, each of said two side portions including a plurality of openings, said molded case including a plurality of protrusions disposed through the plurality of openings of each of said two side portions, in order to mechanically interlock said two side portions to said molded case when said rigid, conductive mounting base is insert molded to said molded case.