Wet etching of cured polyimide

• Main Authors: GLENNING, JOHN JOSEPH, FEGER, CLAUDIUS, HOUGHAM, GARETH GEOFFREY, PAWLOWSKI, WALTER PAUL, BARD, STEVEN LYNDZ, MOLIS, STEVEN EARLE, SNYDER, RANDY WILLIAM, SLOTA, PETER, JR, RITSKO, JOHN JAMES
• Format: Patent
• Language: English; French; German
• Published: 24.01.1990
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; APPARATUS SPECIALLY ADAPTED THEREFOR; BASIC ELECTRIC ELEMENTS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; CHEMISTRY; CINEMATOGRAPHY; COMPOSITIONS BASED THEREON; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROGRAPHY; GENERAL PROCESSES OF COMPOUNDING; HOLOGRAPHY; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; MATERIALS THEREFOR; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; ORIGINALS THEREFOR; PHOTOGRAPHY; PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES,e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTORDEVICES; PHYSICS; PRINTED CIRCUITS; SEMICONDUCTOR DEVICES; THEIR PREPARATION OR CHEMICAL WORKING-UP; WORKING-UP

Polyimide is etched by contacting the polyimide with an aqueous solution of a metal hydroxide followed by contact with an acid followed by contact with an aqueous solution of a metal hydroxide. Etching of chemically cured polyimide can be enhanced by employing a presoaking in hot water. Also, partially etched chemically cured polyimide is removed with a concentrated acid solution. In preparing a metal coated polyimide structure for subsequent gold plating, two flash etching steps with the polyimide etch between are employed after developing the photoresist.