Stamping foils and methods
First Claim
1. A stamping foil for producing electrically conductive circuits on an electrically insulating or poorly conductive substrate;
- said foil being bondable to said substrate in areas activated by compression with a stamping die or stereotype and comprising an electrically conductive layer having a generally decorative or graphic function and having a thickness of between 10 to 35 microns to achieve the required electrical function(s);
said foil being endowed with sufficiently low shear strength to permit sharp separation of said activated areas from unactivated areas of the foil following a stamping operation;
said structure of said conductive layer consisting essentially of fibrous, fibrous-granular or fibrils whose axes are oriented at approximately right angles to the surfaces of said foil and having a diameter between 0.5 and 2 microns; and
a bonding layer adjacent to said conductive layer;
said bonding layer being activatable by compression or heating with said stamping die or stereotype;
whereby said bonding layer effects adhesion of said conductive layer to said substrate in the activated areas.
3 Assignments
0 Petitions
Accused Products
Abstract
A stamping foil for forming printed circuit patterns on insulating or poorly conductive substrates comprising an electrically conductive layer made of a highly conductive metal, such as copper, which is endowed with a sufficiently low shear strength, even in thicknesses of 10 microns or more, to permit easy and sharp separation of the activated (imprinted) and non-activated portions of the foil. Such a low shear strength may be achieved with fibrous or fibrous-granular crystallite structures, wherein the fibers are oriented approximately at right angles to the surfaces of the foil, and, in addition, by doping agents containing carbon, nitrogen and sulfur. The foil may comprise a bonding layer for bonding the conductive layer to a substrate, or such a bonding layer may be applied to the surface of the conductive layer before the stamping operation. The conductive layer may be either self-supporting, or it may adhere to a carrier tape through an intermediary separating layer. In the latter case, the bonding and separating layers become activated when compressed by a stamping die or stereotype, whereby the conductive layer becomes bonded to the substrate and separated from the carrier tape in the activated areas. The activated and non-activated portions of the foil are then separable by pulling the carrier tape away from the substrate.
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Citations
23 Claims
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1. A stamping foil for producing electrically conductive circuits on an electrically insulating or poorly conductive substrate;
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said foil being bondable to said substrate in areas activated by compression with a stamping die or stereotype and comprising an electrically conductive layer having a generally decorative or graphic function and having a thickness of between 10 to 35 microns to achieve the required electrical function(s); said foil being endowed with sufficiently low shear strength to permit sharp separation of said activated areas from unactivated areas of the foil following a stamping operation; said structure of said conductive layer consisting essentially of fibrous, fibrous-granular or fibrils whose axes are oriented at approximately right angles to the surfaces of said foil and having a diameter between 0.5 and 2 microns; and a bonding layer adjacent to said conductive layer; said bonding layer being activatable by compression or heating with said stamping die or stereotype; whereby said bonding layer effects adhesion of said conductive layer to said substrate in the activated areas. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
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Specification