Film-type electrical substrate circuit device and method of forming the device

摘要

An electrical substrate circuit device (10) includes a thick film crossunder conductor (14) and a thin film crossover conductor (16). An intermediate portion of the thick film conductor (14) is covered with a coating (28) of electrically insulating glaze material and opposite end portions (18) of the thick film conductor are electrically connected to thin film contact pads (20) by electrically conductive contact portions (22) in an electrically insulating protective tantalum pentoxide film layer (24). The electrically conductive contact portions (22) are produced by gold material in the end portions (18) of the thick film conductor (14) diffusing into overlying portions of a tantalum film (30) as the tantalum film is converted to the protective tantalum pentoxide film layer (24) by thermal oxidation.