Capacitive mounting arrangement for securing an integrated circuit package to a heat sink

摘要

A thermally conductive mounting flange of an IC package is placed directly on a heat sink surface between respective sections of single layer PC board attached to the heat sink, such that electrical leads extending from opposing sides of the package are positioned over corresponding conductive areas formed on the surface of the respective adjacent PC board section. The leads are electrically coupled with the conductive areas by respective tie-down screws fastened through dielectric isolating washers. The screws are tightened sufficiently against the isolating washers so as to press the respective package leads into solid electrical contact with the conductive areas. Portions of the respective leads and conductive areas surrounding the tie-down screws are cut-away to prevent electrical contact, in order to avoid shorting the leads and/or conductive areas to the heat sink via the tie-down screws. Alternately, respective ends of a retaining spring used to secure the IC package to the heat sink mounting flange are also secured by the package lead tie-down screws, such that the screws both secure the package against the heat sink and press the package leads into solid electrical contact with the respective conductive areas.