Adjusting fillet geometry to couple a heat spreader to a chip carrier

• Main Authors: GAYNES MICHAEL A, DUCHESNE ERIC, BONITZ BARRY A, JOHNSON ERIC A
• Format: Patent
• Language: English
• Published: 03.10.2002
• 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; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; PRINTED CIRCUITS; SEMICONDUCTOR DEVICES; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

An electronic structure, and associated method of fabrication, for coupling a heat spreader above a chip to a chip carrier below the chip. Initially provided is a substrate, a chip on a surface of the substrate and coupled to the substrate, and the heat spreader. Then a fillet of at least one adhesive material is formed on the chip and around a periphery of the chip. Additionally, the heat spreader is placed on a portion of the fillet and over a top surface of the chip. The fillet couples the heat spreader to the substrate. An outer surface of the fillet makes a contact angle of about 25 degrees with the surface of the substrate. The small contact angle not exceeding about 25 degrees prevents cracking of the substrate that would otherwise result from thermal cycling.