Interconnection circuits made from transfer electroforming

Abstract

Abstract An interconnection circuit of unusually fine definition is made in a pollution-free liftoff process using either a rigid mandrel and a flexible substrate onto which the pattern is transferred or a flexible mandrel and a rigid substrate onto which the pattern is transferred. The overplated pattern on the mandrel need have no necessary interconnection border to permit removal thereof from the mandrel. In one embodiment the mandrel is made of glass from which an electroformed pattern is lifted. In this embodiment a permanent metalized pattern on the glass is interspersed with dielectric islands of material, and the liftoff is accomplished by providing an adhesive-coated flexible substrate, such as Kapton, which is pressed over the pattern such that only the overplated pattern is lifted off. While the foregoing utilizes a transparent nonconductive mandrel which includes an overlying transparent conductive layer, less highly defined circuits may be manufactured in the same liftoff manner through the utilization of a conductive mandrel in which the exposed portion of the conductive mandrel forms the appropriate metalized pattern, with dielectric material selectively formed on the mandrel in between the exposed metal. The formation of dielectric islands increases resolution in both the nonconductive and conductive mandrel embodiments and permits the use of a wide variety of metals in the patterning so that metal deposited on metal may be easily lifted off by the adhesive-coated substrate while maintaining fine definition.

Inventors

• 👤 Joseph J. Bakewell

Bibliographic Details