Refrigeration system and method for very large scale integrated circuits

A capillary tube refrigerant expander system for control extraction of heat from an active thermal energy generator comprising:

• cold probe means in thermal contact with the active thermal energy generator and maintaining a first pressure range therein;
• capillary tube means coupled to receive a refrigerant at a pressure substantially higher than the first pressure range, the capillary tube means including capillary outlet means within the cold probe means for rapid expansion of refrigerant at the first pressure range to effect cooling of the cold probe means;
• means coupled to the cold probe means for sensing the temperature thereof;
• and
• means responsive to the sensed temperature for controlling the temperature of the refrigerant before rapid expansion thereof.

A system for maintaining the temperature level of an integrated circuit unit within a nominal low temperature range such that the circuit unit can operate at higher data transfer rates, comprising:

• a high thermal conductivity heat sink structure thermally coupled to the circuit unit;
• cold probe means thermally coupled to the heat sink, the cold probe means including internal capillary refrigerant expansion means adjacent the heat sink structure and return flow tubing means;
• active refrigeration means coupled to supply pressurized refrigerant to the refrigerant expansion;
• and
• passive refrigeration means coupled to the heat sink structure and comprising air cooled heat exchanger means and two phase gas circulation means for passively absorbing thermal energy from the circuit unit when the cold probe means does not maintain a desired operating range of temperature.

The method of subcooling an integrated circuit unit having substantial internal heat buildup to a level of the order of -50.degree. C. with a single refrigerant comprising the steps of:

• actively pressurizing a first refrigerant in a gaseous state while maintaining an ambient temperature therein;
• expanding the refrigerant in the gaseous state to lower the temperature and pressure thereof adjacent the circuit unit until a liquid state is reached;
• extracting thermal energy from the integrated circuit unit with the liquid refrigerant until a gaseous state is reached;
• passing the first refrigerant after expansion in thermal relation to the first refrigerant before expansion to lower the temperature thereof;
• maintaining a second liquid refrigerant in thermal relation to the circuit unit, the evaporation temperature of the second refrigerant being in the ambient range of temperatures;
• extracting thermal energy from gases evaporated from the second liquid refrigerant;
• and
• dissipating thermal-energy from the circuit unit with the second refrigerant when the ambient temperature range is reached due to failure of refrigeration with the first refrigerant.

A system for cooling at least two high density electronic circuit subsystems to substantially below ambient temperature while absorbing internal thermal energy generated by the subsystems comprising:

• refrigeration means providing a flow of high pressure refrigerant;
• an active separate thermal energy exchange system for each subsystem, comprising thermally conductive heat sink means coupled to the subsystem and thermal transfer chamber means in thermal exchange relationship with the heat sink means;
• means within the chamber means for expanding the high pressure refrigerant to a subcooled state in proximity to the heat sink means, and means defining a gas return path from the means for expanding to the refrigeration means;
• and
• a separate backup passive refrigeration system adjacent each heat sink means and comprising a refrigerant chamber in close thermal relation to the heat sink means and a second refrigerant therein that evaporates in the ambient temperature range, a gas distribution system receiving the evaporated refrigerant, and an air heat exchanger spaced apart from the active thermal energy exchange system, and thermally coupled to the gas distribution system for recondensation of the second refrigerant.

A cold probe device for insertion into a receptacle of a heat sink for refrigeration of a thermally coupled active electronic circuit device, comprising:

• a thermally conductive housing for insertion in substantially mating relation into the heat sink receptacle, the housing having broad vertical sides and narrow vertical and horizontal edges and an open interior, and an inlet opening at an intermediate region of one of the vertical edges;
• heat exchanger means within the interior of the housing and distributed through a substantial majority of the volume thereof, the heat exchanger means being thermally coupled to at least one broad side of the housing;
• capillary means extending throughout the inlet opening in the heat exchanger means and having an outlet for providing a pressurized refrigerant within the housing;
• and
• conduit means communicating with the interior of the housing via the inlet opening for providing an outlet flow path for gas phase refrigerant.

A system for extraction of heat energy from separate active high density integrated circuit modules mounted on a printed circuit board slidable into an engagement position in a circuit counsel, comprising:

• separate heat sink means thermally coupled to each of the separate circuit units, each of the heat sink means including a side receptacle on the entry side of the printed circuit board;
• a number of cold probe means, each configured and positioned to fit into the side aperture of a different heat sink means when the printed circuit board is slid into engagement position;
• a refrigeration system providing pressurized refrigerant to each of the cold probe means;
• and
• means for recirculating refrigerant from the cold probe means to the refrigeration system, the refrigerant having received thermal energy from the associated high density integrated circuit and convecting to energy to a low pressure gas phase therein.