Method of fabricating high surface to volume ratio structures and their integration in microheat exchangers for liquid cooling system
View Patent ↗An structure and method of manufacturing a microstructure for use in a heat exchanger is disclosed. The heat exchanger comprises a manifold layer and an microstructured region. The manifold layer comprises a structure to deliver fluid to the microstructured region. The microstructured region is formed from multiple windowed layers formed from heat conductive layers through which a plurality of microscaled apertures have been formed by a wet etching process. The plurality of windowed layers are then coupled together to form a composite microstructure.
1. A method of fabricating a heat exchanger comprising microstructures, the method comprising:
a. forming a plurality of microscaled apertures through a plurality of heat conductive layers using a material removal process to form a plurality of windowed layers; and
b. forming a micromesh within a composite microstructure by coupling the plurality of windowed layers together to form the composite microstructure, wherein each microscaled aperture of a windowed layer is in communication with a plurality of microscaled apertures of an adjacent windowed layer.
2. The method of fabricating a heat exchanger of claim 1 , wherein the plurality of windowed layers are coupled together by brazing.
3. The method of fabricating a heat exchanger of claim 2 , wherein the brazing is done with a brazing material comprising silver.
4. The method of fabricating a heat exchanger of claim 2 , wherein one or more of the plurality of windowed layers are plated with a brazing material prior to brazing.
5. The method of fabricating a heat exchanger of claim 1 , wherein the step of forming the plurality of microscaled apertures through each of the plurality of heat conductive layers using a material removal process comprises forming a first micropattern in a first side of each heat conductive layer and a second micropattern in a second side of each heat conductive layer.
6. The method of fabricating a heat exchanger of claim 5 , wherein the first and second micropatterns are complementary to form continuous microchannels in the heat conductive layer.
7. The method of fabricating a heat exchanger of claim 5 , wherein the first and second micropatterns are designed to form an overlapping micromesh structure in the heat conductive layer.
8. The method of fabricating a heat exchanger of claim 1 , wherein the material removal process is an isotropic wet etching process.
9. The method of fabricating a heat exchanger of claim 8 , wherein the isotropic wet etching process is selected from a group consisting of photo chemical machining, through mask chemical etching, through mask electrochemical etching, electroetching, and electrochemical micromachining.
10. The method of fabricating a heat exchanger of claim 1 , wherein the heat conductive layers comprise copper.
11. The method of fabricating a heat exchanger of claim 1 , further comprising a step of aligning apertures in each of the plurality of windowed layers before coupling the plurality of windowed layers together.
12. The method of fabricating a heat exchanger of claim 1 , wherein the micromesh is integrally formed with the composite microstructure.
13. The method of fabricating a heat exchanger of claim 1 , wherein the composite microstructure comprises a plurality of microchannels.
14. The method of fabricating a heat exchanger of claim 1 , wherein the heat conductive layers have a thickness between about 50 and about 250 micrometers.
15. The method of fabricating a heat exchanger of claim 1 , wherein the microscaled apertures formed in the heat conductive layers have length and width dimensions between about 50 and about 300 micrometers.
16. A method of fabricating a heat exchanger comprising microstructures, the method comprising:
a. forming a plurality of elongated and parallel microscaled apertures through a plurality of heat conductive layers using a material removal process to form a plurality of windowed layers; and
b. forming a micromesh within a composite microstructure by coupling the plurality of windowed layers together to form the composite microstructure, wherein microscaled apertures of a first windowed layer are non-parallel with microscaled apertures of an adjacent windowed layer.