US 5,403,700 A · Method of making a thin film electrical component

Abstract

A biocompatible thin film electrical component is configured for use in a human body or other ionic liquid environment. A polyimide substrate is bonded to a glass carrier plate sized for handling by automatic equipment and a multiple-layer metal conductor is deposited on the substrate and patterned to define an electrical circuit or biosensor. The polyimide and the glass establish a bond therebetween that withstands handling yet is broken using biocompatible releasing agents and techniques. The polyimide substrate and glass carrier plate preferably have similar thermal expansion properties to reduce the likelihood of fracture and delamination problems during release of the substrate from the carrier plate. An insulation layer covers the metal conductor and, in one embodiment, is made of a polyimide having a cure temperature lower than the temperature at which interdiffusion occurs in the metal layers in the conductor.

Claims8

Dependent claims

A method of making a thin film electrical circuit, the method comprising the steps of

providing a rigid glass carrier plate having a flat surface, coating the flat surface with a first polyamic acid precursor solution, curing the first polyamic acid precursor solution using heat at a first temperature to provide a layer of polyimide film bonded to the flat surface, the polyimide film having a coefficient of thermal expansion that is substantially equivalent to the coefficient of thermal expansion of the rigid glass carrier plate to that creation of internal stresses in the polyimide film during curing is avoided, and
forming means for providing an electrical circuit on the polyimide film.

Dependencies are inferred from the claim text.

Method of making a thin film electrical component

Life of this patent

Method of making a thin film electrical component

Life of this patent

Abstract

Claims8