Northrop Grumman Systems Corporation

Westinghouse Electric Corporation

Electric Power Research Institute Incorporated

Thomas J Fagan, Jr

Paul G Kennedy

Robin E Hamilton

John A Ostop

Gregory Alan Arlow

Martin L Baker

John C Golombeck

Robert Draper

Stephen E Veyo

Francis J Sisk

Robert S Lackey

Joseph R Humphrey

William S Woodward

Cooling of densely packaged semiconductor devices is achieved by microchannels which extract heat by forced convection and the use of fluid coolant located as close as possible to the heat source. The microchannels maximize heat sink surface area and provides improved heat transfer coefficients, thereby allowing a higher power density of semiconductor devices without increasing junction temperature or decreasing reliability. In its preferred embodiment, a plurality of microchannels are formed directly in the substrate portion of a silicon or silicon carbide chip or die mounted on a ground plane element of a circuit board and where a liquid coolant is fed to and from the microchannels through the ground plane. The microchannels comprise a plurality of closed-ended slots or grooves of generally rectangular cross section. Fabrication methods include deposition and etching, lift-off processing, micromachining and laser cutting techniques.

Method of extracting heat from a semiconductor body and forming

A closed loop liquid cooling system for an RF transistor module including a plurality of elongated microchannels connected between a pair of coolant manifolds for conducting liquid coolant beneath one or more transistor dies to dissipate the heat generated thereby, a heat exchanger, a miniature circulating pump located on the module, and passive check valves having tapered passages for controlling the flow of coolant in the loop. The valves are truncated tapered passage microchannel valves having no moving parts and are fabricated so as to be a part of either the circulating pump, the coolant manifolds, or the microchannels.

Closed loop liquid cooling for semiconductor RF amplifier modules

Microchannel cooling of high power semiconductor devices

An indoor unit for an electric heat pump is provided in modular form including a refrigeration module 10, an air mover module 12, and a resistance heat package module 14, the refrigeration module including all of the indoor refrigerant circuit components including the compressor 36 in a space adjacent the heat exchanger 28, the modules being adapted to be connected to air flow communication in several different ways as shown in FIGS. 4-7 to accommodate placement of the unit in various orientations.

Indoor unit for electric heat pump

Apparatus for rotating a driven shaft in the same direction at two different speeds upon rotation of a drive shaft in respective, opposed directions. The apparatus includes a sun gear on the drive shaft, a ring gear on the driven shaft, a planet carrier rotatably mounted on the drive shaft, adjacent to the sun gear, one or more planetary gears rotatably mounted on the planet carrier and in mesh with the sun and ring gears. An over-running clutch locks the planet carrier to the drive shaft when the latter rotates in one direction to thereby lock the planetary gears to the sun and ring gears to cause rotation of the ring gear and the driven shaft in a first direction at a first speed. A sprag prevents rotation of the planet carrier relative to a fixed support when the drive shaft rotates in the opposite direction to thereby allow rotation of the planetary gears about fixed axes to rotate the ring gear and thereby the driven shaft in the first direction at a second speed.

Two-speed drive apparatus

Individual wires in a winding are formed as polygons having contacting faces and noncontacting faces. Contacting faces of adjacent wires are positively engaged, while the noncontacting faces of adjacent wires form the periphery of openings that extend through the winding. Insulation may be removed from the noncontacting faces to facilitate cooling.

Superconductive winding with cooling passages

Growing community of inventors

Pittsburgh, PA, United States of America

Thomas J Fagan, Jr