Aperture formation in aluminum circuit card for enhanced thermal dissipation

• Main Authors: IMKEN; RONALD L, LATORRE; JOSEPH
• Format: Patent
• Language: English
• Published: 30.03.1993
• Subjects: BASIC ELECTRIC ELEMENTS; BOOK COVERS; BOOKBINDING; CALCULATING; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; COMPUTING; COUNTING; DEVICES FOR USE THEREWITH AND NOT OTHERWISE PROVIDEDFOR; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; FILES; HANDLING RECORD CARRIERS; LOOSE LEAVES; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS; MOVABLE-STRIP WRITING OR READING APPARATUS; PERFORMING OPERATIONS; PHYSICS; PRESENTATION OF DATA; PRINTED CIRCUITS; PRINTED MATTER CHARACTERISED BY IDENTIFICATION OR SECURITYFEATURES; PRINTED MATTER OF SPECIAL FORMAT OR STYLE NOTOTHERWISE PROVIDED FOR; RECOGNITION OF DATA; RECORD CARRIERS; SEMICONDUCTOR DEVICES; SPECIAL PRINTED MATTER; TRANSPORTING

A method and system are provided for forming apertures in the dielectric layers of an aluminum circuit to allow electrical connection to the aluminum core and enhance the thermal efficiency of integrated circuit devices attached thereto. Specifically, the apertures are formed to accommodate the ICs and allow them to be in direct contact with the aluminum core layer of the circuit card. The apertures are formed by placing a photoresist material on the aluminum core in locations corresponding to the desired locations of the aperture. The photoresist material is used as a "placeholder" during subsequent processing. The aluminum is then anodized to form aluminum oxide and a polymer material is then electrophoretically placed over the aluminum oxide. The photoresist "placeholder" is then removed, leaving an aperture that will accommodate an IC. The top of the polymer layer can then be circuitized to interconnect the chips.