PHOTOGRAPHIC PROCESS FOR PRODUCING ELECTRICAL COMPONENTS

摘要

1,273,267. Resistors; capacitors; printed Circuits. ITEK CORP. 28 March, 1969 [1 April, 1968; 16 April, 1968], No. 16264/69. Headings H1M, H1R and H1S. [Also in Division G2] A photographic process for making substantially continuous electrically conductive metal images comprises image-wise exposing a layer of photoconductive material on a support to form a reversible latent image and developing the image with a developer comprising metal ions and a reducing agent so as to deposit sufficient metal to produce the electrically conductive image. The photoconductive material is preferably titanium dioxide, but may be zinc oxide, zirconium dioxide, germanium dioxide, indium trioxide, tin oxide, barium titanate, cadmium sulphide, zinc sulphide, tin disulphide or cadmium selenide. The metal ion may be Ag+ deposited from a viscous layer of silver nitrate on immersion in a solution of Metol containing 60 g/l. citric acid. Other ions deposited may be Hg++ pb++++ Au+++ Pt++++ Ni++ Sn++ Pb++ Cu+ Cu++, and alternative reducing agents are listed. Capacitors may be made by applying the process on a substrate comprising aluminium, nickel, copper titanium or chromium affixed to a silicon dioxide or glass base which forms one electrode, the deposited layer forming the other layer. Alternatively the process may be applied to each side of a polyester film, the capacity being between the deposited layers. Printed circuits may be made by applying the process on a substrate of wood, rag or pulp paper, polyethylene terephthalate, celluloseacetate, cloth, glass or oxidized silicon. The conductor pattern may be strengthed by electroless or electrolytic deposition. Resistors are provided by parts of a printed circuit of reduced width which received a smaller amount of energy during the exposure step whereby fewer metallic ions are deposited.