Process for producing adherent, electrochemically reinforcible and solderable metal layers on an aluminum-oxide containing ceramic substrate

US4780332A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Birgit Pitz · Stuttgart, DE
• Helmut Sautter · Ditzingen, DE
• Lothar Weber · Stuttgart, DE

Key dates

• Filing date: Oct 8, 1986
• Grant date: Oct 25, 1988
• Expiry date: Oct 8, 2006

Classification

• Technology area (CPC H): Electricity
• CPC primary: H05K3/181
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A screen-printing paste containing Cu.sub.2 O or NiO and preferably aluminum oxide or, more preferably, an aluminum compound such as aluminum acetylacetonate which forms aluminum oxide under calcination heat, is printed over an entire surface of a substrate consisting of aluminum oxide ceramic, after which it is calcined in air at from 800.degree. to 1350.degree. C. to produce an adhesion-promoting spinel layer. That layer is then metallized by plating in an electroless bath for deposition of copper or nickel, as the case may be, after which the metal layer thus deposited is reinforced galvanically. A positive photoresist layer can be applied to the electroless deposited copper or nickel layer, illuminated through an appropriate mask and developed to expose a desired pattern of the underlying electroless copper layer for galvanic reinforcement, so that after removal of the unexposed portion of the mask the unreinforced electroless layer can be removed by etching without impairment of the reinforced conducting pattern.