International Rectifier Corporation

Stephen Nicholas Siu

Ajit Dubhashi

Bertrand Vaysse

Heny W Lin

Michael A Corfield

A power module having a power circuit board free of mounting holes and more usable surface area for disposition of copper traces is shown. The power module includes a power shell that snaps onto the underside of the power circuit board. The power shell has embedded therein a thermally conductive substrate. One or a plurality of power semiconductor devices are disposed over one side of the thermally conductive substrate. A heatsink is mounted to the underside of the power shell in thermal contact with the thermally conductive substrate. The heatsink is mounted to the underside of the power shell by a heatsink retainer which biases the heatsink against the substrate. The heatsink retainer is mounted on retainer posts which extend from the underside of the power shell.

Heatsink retainer

A flexible power assembly (FPA) provides a new packaging concept suitable for motor control and other functions. An insulated metal substrate (IMS) supports power semiconductor devices and is mounted directly on a heatsink, which supports a circuit board that is mounted above and spaced from the top side of the IMS. There are provided devices that are mounted on the circuit board which are electrically connected to the power semiconductor devices. There may be a cavity in the circuit board allowing the top of the IMS to be exposed, and optionally providing access for bonding wires to the top of the circuit. Bonding pads may be provided on the circuit board for electrical connection with the bonding wires. A cover may be optionally provided to enclose a space over the cavity. Potting compound may be contained in the space created by the cavity.

Flexible power assembly

An insert-molded leadframe having wire bonding posts formed on an inner portion, device pins formed on an outer portion, and a central portion connecting between the inner portion and the outer portion. Plastic encases the central portion of the conductive leadframe, such that the bonding posts and the device pins are exposed at inner and outer edges, respectively, of the plastic casing. The bonding posts and the device pins are disposed substantially perpendicular to one another. The conductive leadframe is formed with the bonding posts in a first plane and the device pins in a second plane, the first and second planes being substantially mutually parallel. The conductive leadframe then is encased in plastic by injection molding to form the insert-molded leadframe of the invention. An IMS substrate with powertrain electronics is adhered to the bottom of the bonding posts at the inner edge of the insert-molded leadframe, and the powertrain electronics are electrically connected by wire bonding to the top of the bonding posts. A circuit board containing driver electronics is mounted on and electrically connected to the device pins at the outer edge of the plastic casing.

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Los Angeles, CA, United States of America

Stephen Nicholas Siu