Selective coating

Abstract

Abstract IN MAKING A DIODE ARRAY TARGET FOR A TELEVISION CAMERA TUBE FROM A SILICON SUBSTRATE, THE FACE OF THE SUBSTRATE IS FLOODED WITH A PHOTORESIST MASKING MATERIAL AND THE SUBSTRATE S THEN SPUN TO FORM A UNIFORM COATING OF THE MATERIAL ON THE FACE. DUE TO THE OVERFLOWING, BREAKING DOWN AND SCATTERING OF THE MATERIAL ON THE SUBSTRATE AND DUE TO LEAKAGE FROM A VACUUM SPINDLE HOLDING THE SUBSTRATE, THE MATERIAL OFTEN CREEPS OVER, OR SPLASHES ON, THE BACKSIDE OF THE SUBSTRATE OPPOSITE THE FACE. THIS RESULTS IN A DECREASE IN THE UNIFORMITY OF THE DIODE ARRAY AND REQUIRES AN ADDITIONAL PROCESSING STEP TO MAKE THE TARGET. TO PREVENT THE MATERIAL FROM CREEPING OVER, OR SPLASHING ON, THE BACKSIDE AND THEREBY REDUCE THE PROCESSING STEPS AND INCREASE THE UNIFORMITY OF THE DIODE ARRAY, A FLUID IS FORCED OUTWARD IN AN ANNULAR PATTERN FROM THE CENTER OF THE SUBSTRATE AND AGAINST THE BACKSIDE AS IT IS SPUN. AN APPARATUS FOR EFFECTING THIS FLOW INCLUDES AN ANNULAR NOZZLE POSITIONED BENEATH THE SUB- STRATE AND FORMED BY AN UPPER BEVELED FLANGE AND A COACTING CHAMFERED PORTION OF A PAIR OF TUBULAR MEMBERS.

Inventors

• 👤 Lynn Forrest Boyer
• 👤 Anderson Forbes Johnson Jr

Bibliographic Details