Heat-resistant insulating coating material and thermal head making use thereof
US5157107A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Aug 29, 1989 |
| Grant date | Oct 20, 1992 |
| Priority date | — |
| Expiry date | Aug 29, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/4676
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A polymeric acid is synthesized by the ring-opening poly-addition reaction using a biphenyl tetracarboxylic acid as a tetracarboxylic acid moiety and an aromatic diamine, particularly p-phenylene diamine, as a diamine moiety. An aromatic polyimide resin layer possessing a highly desirable heat-resisting property as a heat-resistant insulating coating material and excelling in adhesive strength relative to a substrate is obtained by adjusting the polymeric acid in viscosity with a suitable organic solvent, applying the resultant polyamic acid on a substrate, and firing the applied layer of the polyamic acid. The substrate, for example, is a conductor layer formed as with copper and used as a multi-layer wiring board for hybrid IC's. In a thermal head which is obtained by forming an insulating layer on a metallic substrate and superposing a multiplicity of heat-generating resistors and conductors connected severally to the heat-generating resistors on insulating layer, the aforementioned aromatic polyamide resin layer is formed on the metallic substrate. This aromatic polyimide resin layer as an insulating layer in the thermal head withstands harsh working temperature conditions and …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.