MEMS heat pumps for integrated circuit heat dissipation

Abstract

A cooling mechanism within an integrated circuit includes an internal pump for circulating thermally conductive fluid within closed loop channels. The cooling channels are embedded within an integrated circuit die, such as in interlevel dielectric layers between metal levels. The channels are formed by engineering deposition of a layer to line trenches and form continuous voids along the trenches. Exemplary heat pumps comprise cavities, formed in communication with the channels, covered by piezoelectric actuators. Preferably, the actuators are wired to act in sequence as a peristaltic pump, circulating the fluid within the channels. The channels are positioned to carry heat from active devices within the integrated circuit, and a heat sink carries heat from the die.

1 . A dynamic random access memory chip, comprising a network of internal cooling channels filled with a thermally conductive fluid, the thermally conductive fluid disposed to circulate through the cooling channels by an electromechanical pump disposed along the channels.  
   
   
       2 . The dynamic random access memory chip of  claim 1 , wherein the fluid is selected from the group consisting of argon, helium, krypton and xenon.  
   
   
       3 . The dynamic random access memory chip of  claim 1 , wherein the electromechanical pump comprises a piezoelectric actuator over a cavity in fluid communication with the cooling channels.  
   
   
       4 . The dynamic random access memory chip of  claim 3 , further comprising a plurality of piezoelectric actuators arrayed along the channels to form a peristaltic pump.  
   
   
       5 . The dynamic random access memory chip of  claim 1 , further comprising a heat sink in thermal communication with the die.  
   
   
       6 . The dynamic random access memory chip of  claim 5 , wherein the heat sink is bonded to an outer surface of the chip.  
   
   
       7 . The dynamic random access memory chip of  claim 6 , wherein the heat sink is bonded to the outer surface of the chip by a thermally conductive adhesive.  
   
   
       8 . The dynamic random access memory chip of  claim 7 , wherein the adhesive comprises epoxy.  
   
   
       9 . The dynamic random access memory chip of  claim 5 , wherein the heat sink comprises copper.  
   
   
       10 . The dynamic random access memory chip of  claim 5 , wherein the heat sink occupies greater than about 80% of the chip surface area.  
   
   
       11 . The dynamic random access memory chip of  claim 1 , wherein the channels are defined by a silicon carbide coating of a plurality of trenches.  
   
   
       12 . The dynamic random access memory chip of  claim 1 , wherein the pump is disposed within the chip.