INJECTABLE HEAT SINK

Abstract

A heat sink arrangement includes a housing associated with an electronic heat source. The housing has a cavity adjacent to the heat source. A thermally conductive, electrically insulating foam heat sink is disposed in the cavity and draws heat out of the heat source. The foam heat sink may be formed of a two-part epoxy.

Claims

1. A method of removing heat from an electronic heat source that is associated with a housing having a cavity, the method comprising: blowing a liquid foam into the cavity; waiting for the liquid foam to cure into a solid or semi-solid foam inside the cavity; operating the electronic heat source; and using the solid or semi-solid foam in the cavity to draw heat out of the electronic heat source.

2. The method of claim 1 wherein the cavity is adjacent to the heat source.

3. The method of claim 1 further comprising: providing a first container containing a first epoxy part and a first blowing agent part; providing a second container containing a second epoxy part and a second blowing agent part; and mixing contents of the first container and contents of the second container in a nozzle to form the liquid foam, the blowing including blowing the liquid foam into the cavity from the nozzle.

4. The method of claim 1 wherein the solid or semi-solid foam is thermally conductive and electrically insulating.

5. The method of claim 1 wherein gaseous carbon dioxide is trapped within the solid or semi-solid foam.

6. The method of claim 1 wherein the solid or semi-solid foam substantially fills the cavity.

7. The method of claim 1 wherein the blowing includes blowing the liquid foam into an electrical contact fitting connected to the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above-mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:

[0016] FIG. 1 is a schematic diagram of one embodiment of a heat sink arrangement of the present invention.

[0017] FIG. 2 is a diagram of the blowing agent chemistry of one embodiment of a heat sink arrangement of the present invention.

[0018] FIG. 3 is a flow chart of a method of the present invention for removing heat from an electronic heat source that is associated with a housing having a cavity.

DETAILED DESCRIPTION

[0019] The embodiments hereinafter disclosed are not intended to be exhaustive or limit the invention to the precise forms disclosed in the following description. Rather the embodiments are chosen and described so that others skilled in the art may utilize its teachings.

[0020] FIG. 1 illustrates one embodiment of a heat sink arrangement 10 of the present invention, including a two-part foam injection system with a customized injection nozzle. More particularly, arrangement 10 includes a first container tank 12, a second container tank 14, a first hose 16, a second hose 18, a mixing injection nozzle 20, and an electronic assembly 22. First tank 12 contains a mixture of water and epoxy part A, which is one part of a two-part, thermally conductive, electrically insulating epoxy. Second tank 14 contains a mixture of isocyanate and epoxy part B, which is the other part of the two-part epoxy. Isocyanate has the formula RNCO.

[0021] First hose 16 carries the mixture from first tank 12 to nozzle 20, and second hose 18 carries the mixture from second tank 14 to nozzle 20. The water from first hose 16 and the isocyanate from second hose 18 mix together in nozzle 20 to form a carbon dioxide blowing agent. The formation of carbon dioxide may create high pressure in nozzle 20 for blowing the contents of nozzle 20 out of nozzle 20. FIG. 2 describes in molecular terms the chemical formulation of the blowing agent in nozzle 20.

[0022] Electronic assembly 22 includes an electrical contact fitting 24, a housing 25 having a cavity 26, and a heat source 28. Heat source 28 is schematically depicted in FIG. 1 as a shaded area, but may include any electronic source of heat, such as transistors, power amplifiers, integrated circuits, etc.

[0023] During use, nozzle 20 is inserted into a housing of electronic assembly 22. More specifically, nozzle 20 is inserted into electrical contact fitting 24 in the embodiment of FIG. 1. Nozzle 20 can then be opened to thereby commence a flow of fluid foam from a mixture of the contents of tanks 12 and 14 into the open space of cavity 26. The foam may completely fill cavity 26 and cure/solidify and expand into a solid or semi-solid heat sink foam within cavity 26. After the foam has expanded in cavity 26, nozzle 20 may be removed from electrical contact fitting 24.

[0024] During the operation of electronic assembly 22, the foam, thermally conductive, electrically insulating heat sink within cavity 26 may absorb or draw heat from heat source 28, and thereby cool heat source 28.

[0025] FIG. 3 is a flow chart of a method 300 of the present invention for removing heat from an electronic heat source that is associated with a housing having a cavity. In a first step 302, a liquid foam is blown into the cavity. For example, nozzle 20 can blow a liquid foam into cavity 26.

[0026] In a next step 304, waiting takes place for the liquid foam to cure into a solid or semi-solid foam inside the cavity. For example, it is possible that no positive actions occur while the foam cures/solidifies into a solid or semi-solid foam that functions as a heat sink within cavity 26.

[0027] Next, in step 306, the electronic heat source is operated. For example, voltage may be applied to the electronics of heat source 28, thereby causing the electronics to operate and create heat.

[0028] In a final step 308, the solid or semi-solid foam in the cavity is used to draw heat out of the electronic heat source. For example, the foam heat sink within cavity 26 may absorb or draw heat from heat source 28.

[0029] While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.