Electrical coupling of a stiffener to a chip carrier

• Main Authors: DORNBOS TERRY J, PIERSON MARK V, THOMAS DAVID L, PHILLIPS, JR. RAYMOND A, RUDIK WILLIAM J
• Format: Patent
• Language: English
• Published: 02.03.2004
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PRINTED CIRCUITS; SEMICONDUCTOR DEVICES

A method and structure for conductively coupling a metallic stiffener to a chip carrier. A substrate has a conductive pad on its surface and an adhesive layer is formed on the substrate surface. The metallic stiffener is placed on the adhesive layer, wherein the adhesive layer mechanically couples the stiffener to the substrate surface and electrically couples the stiffener to the pad. The adhesive layer is then cured such as by pressurization at elevated temperature. Embodiments of the present invention form the adhesive layer by forming an electrically conductive contact on the pad and setting a dry adhesive on the substrate, such that the electrically conductive contact is within a hole in the dry adhesive. The electrically conductive contact electrically couples the stiffener to the pad. The curing step includes curing both the dry adhesive and the electrically conductive contact, resulting in the dry adhesive adhesively coupling the stiffener to the substrate. The electrically conductive contact may include an electrically conductive adhesive or a metallic solder. Additional embodiments of the present invention form the adhesive layer by applying an electrically conductive adhesive on the substrate, wherein after the stiffener is placed on the adhesive layer, the electrically conductive adhesive mechanically and electrically couples the stiffener to the surface of the substrate.