Abstract: The adhesion of chromium-copper layer to polyimide has been greatly improved by a method which provides controlled reduction, rather than total elimination, of water content in the polyimide. The electronic packaging device which incorporates the flexible circuit prepared by the method exhibits greatly improved reliability. It is believed that the invention can be used to improve the adhesion between other organic materials having moisture affinity and materials comprising in-organics or between two organic materials.

Abstract: A metallic layer is coated onto a polyimide substrate by sputtering a layer of chromium followed by a layer of copper whereby the rate of deposition of the chromium is about 4 angstroms/second or less.

Abstract: A method of making a circuitized substrate wherein a dielectric layer is provided having a first layer of metallic material thereon. A first metallic member is formed on the dielectric's metallic layer, following which a pair of openings are precisely provided within a second dielectric material located on the dielectric. These openings in turn define a selected area on the first metallic member and, significantly, a precisely oriented pattern of the first metallic layer at a spaced distance from the metallic member. This metallic pattern serves as a mask to permit formation of an opening through the dielectric, which opening in turn may be engaged by tooling or the like such as may be used to position an electronic component, e.g., semiconductor device, on the underlying substrate.