Patent ID: 6606792
Filing Date: 2003-08-19
Classification: H05K,Y10T

Abstract:
A process for forming a printed circuit substrate with impedance elements comprising performing step (a) or (b):(a) depositing a layer of an impedance material on a first surface of a sheet of an electrically highly conductive material and attaching a second surface of the sheet of electrically highly conductive material to a support; then; (b) attaching a second surface of a sheet of electrically highly conductive material to a support and depositing a layer of an impedance material on a first surface of the sheet of electrically highly conductive material; then (c) applying a layer of a photoresist material onto the layer of impedance material; (d) imagewise exposing the photoresist material thus forming image areas and nonimage areas, and then removing the nonimage areas while retaining the image areas; (e) etching away a portion of the impedance layer material underlying the removed nonimage areas of the photoresist material, and then optionally removing the image areas of the photoresist material thus leaving a pattern of impedance elements on the sheet of electrically highly conductive material, (f) forming a plurality of target holes through the sheet of electrically highly conductive material; (g) attaching one side of a sheet of insulating material to the sheet of electrically highly conductive material such that the impedance elements are between the sheet of insulating material and the sheet of electrically highly conductive material; (h) removing the support from the sheet of electrically highly conductive material; (i) applying an additional layer of a photoresist material onto the second surface of the sheet of electrically highly conductive material; (j) imagewise exposing the additional layer of photoresist material thus forming image and nonimage areas, and then removing the nonimage areas while retaining the image areas; (k) etching away the portion of the sheet of electrically highly conductive material underlying the removed nonimage areas of the photoresist material, and then optionally removing the image areas of the photoresist material thus leaving a pattern of conductive lines of the highly conductive material such that at least some of the conductive lines contact at least some of the impedance elements.