Microheat exchanger for laser diode cooling

• US 8,254,422 B2
• Filed: 08/05/2009
• Issued: 08/28/2012
• Est. Priority Date: 08/05/2008
• Status: Active Grant

• Current Assignee: Vertiv Corporation (Vertiv Holdings Co.)
• Original Assignee: Cooligy Incorporated (Emerson Electric Company)
• Inventors: Datta, Madhav, Leong, Brandon, McMaster, Mark
• Primary Examiner(s): Rodriguez, Armando
• Application Number:
  US12/536,361
• Publication Number:
  US 20100032143A1
• Time in Patent Office: 1,119 Days
• Field of Search: 372/34, 372/35, 372/36
• US Class Current: 372/35
• CPC Class Codes: C04B 2237/12 Metallic interlayers
• CPC Class Codes: C04B 2237/122 based on refractory metals
• CPC Class Codes: C04B 2237/124 based on copper
• CPC Class Codes: C04B 2237/125 based on noble metals, e.g. silver
• CPC Class Codes: C04B 2237/127 The active component for bonding being a refractory metal
• CPC Class Codes: C04B 2237/34 Oxidic
• CPC Class Codes: C04B 2237/343 Alumina or aluminates
• CPC Class Codes: C04B 2237/366 Aluminium nitride
• CPC Class Codes: C04B 2237/40 Metallic
• CPC Class Codes: C04B 2237/403 Refractory metals
• CPC Class Codes: C04B 2237/405 Iron metal group, e.g. Co or Ni
• CPC Class Codes: C04B 2237/407 Copper
• CPC Class Codes: C04B 2237/408 Noble metals, e.g. palladium, platina or silver
• CPC Class Codes: C04B 2237/592 whereby the interlayer is not continuous, e.g. not the whole surface of the smallest substrate is covered by the interlayer
• CPC Class Codes: C04B 2237/62 Forming laminates or joined articles comprising holes, channels or other types of openings
• CPC Class Codes: C04B 2237/704 of one or more of the ceramic layers or articles
• CPC Class Codes: C04B 2237/706 of one or more of the metallic layers or articles
• CPC Class Codes: C04B 2237/708 of one or more of the interlayers
• CPC Class Codes: C04B 2237/72 Forming laminates or joined articles comprising at least two interlayers directly next to each other
• CPC Class Codes: C04B 2237/74 Forming laminates or joined articles comprising at least two different interlayers separated by a substrate
• CPC Class Codes: C04B 37/026 : consisting of metals or metal salts
• CPC Class Codes: F28F 7/02 : Blocks traversed by passages for heat-exchange media F28D7/0008 takes precedence
• CPC Class Codes: H01L 23/3735 : Laminates or multilayers, e.g. direct bond copper ceramic substrates
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 1/0203 : Cooling of mounted components H05K1/0272 takes precedence
• CPC Class Codes: H05K 1/0207 : using internal conductor planes parallel to the surface for thermal conduction, e.g. power planes
• CPC Class Codes: H05K 1/0272 : Adaptations for fluid transport, e.g. channels, holes
• CPC Class Codes: H05K 1/0306 : Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 2201/0355 : Metal foils
• CPC Class Codes: H05K 2201/064 : Fluid cooling, e.g. by integral pipes
• CPC Class Codes: H05K 3/0061 : onto a metallic substrate, e.g. a heat sink heat sinks for electric apparatus H05K7/20
• CPC Class Codes: H05K 3/38 : Improvement of the adhesion between the insulating substrate and the metal
• CPC Class Codes: H05K 3/4629 : laminating inorganic sheets comprising printed circuits, e.g. green ceramic sheets
• CPC Class Codes: H05K 3/4641 : having integrally laminated metal sheets or special power cores
• CPC Class Codes: Y10T 428/24612 : Composite web or sheet
• CPC Class Codes: Y10T 428/31678 : Of metal

Abstract

A microheat exchanging assembly is configured to cool one or more heat generating devices, such as integrated circuits or laser diodes. The microheat exchanging assembly includes a first ceramic assembly thermally coupled to a first surface, and in cases, a second ceramic assembly thermally coupled to a second surface. The ceramic assembly includes one or more electrically and thermally conductive pads to be thermally coupled to a heat generating device, each conductive pad is electrically isolated from each other. The ceramic assembly includes a ceramic layer to provide this electrical isolation. A top surface and a bottom surface of the ceramic layer are each bonded to a conductive layer, such as copper, using an intermediate joining material. A brazing process is performed to bond the ceramic layer to the conductive layer via a joining layer. The joining layer is a composite of the joining material, the ceramic layer, and the conductive layer.

Claims

1. A device comprising:

a. a heat exchanging device comprising a thermally conductive material, wherein the heat exchanging device is configured to transfer heat from the thermally conductive material to a fluid flowing therethrough; and

b. a thermally conductive ceramic assembly thermally coupled to the heat exchanging device, wherein the ceramic assembly comprises;

i. a conductive layer;

ii. a ceramic layer; and

iii. an active brazing alloy bonded between the conductive layer and the ceramic layer to form a joining layer, wherein the conductive layer and the joining layer are configured to form one or more electrically isolated conductive pads.

2. The device of claim 1 wherein the conductive layer and the joining layer are patterned to form a plurality of electrically isolated pads, further wherein each of the plurality of electrically isolated pads are electrically isolated from each other by the ceramic layer.

3. The device of claim 1 wherein the ceramic assembly further comprises a second conducive layer and a second active brazing alloy layer bonded between the second conductive layer and the ceramic layer to form a second joining layer.

4. The device of claim 3 further comprising a metal-to-metal joining layer bonded between the second conductive layer of the ceramic assembly and the heat exchanging device.

5. The device of claim 1 wherein the conductive layer and the heat exchanging device are copper-based.

6. The device of claim 1 wherein the ceramic layer comprises beryllium oxide, aluminum oxide, or aluminum nitride.

7. The device of claim 1 wherein the active brazing alloy comprises a copper-based active brazing alloy, a copper-silver-based active brazing alloy, or an indium-copper-silver-based active brazing alloy.

8. The device of claim 1 wherein the active brazing alloy layer is comprised of an active joining material paste or an active joining material foil.

9. The device of claim 1 further comprising a second thermally conductive ceramic assembly thermally coupled to an opposite side of the heat exchanging device than the ceramic assembly.

10. A device comprising:

a. a heat exchanging device comprising a thermally conductive material, wherein the heat exchanging device is configured to transfer heat from the thermally conductive material to a fluid flowing therethrough; and

b. a thermally conductive ceramic assembly thermally coupled to the heat exchanging device, wherein the ceramic assembly comprises;

i. a conductive layer;

ii. a ceramic layer including a metallized first surface; and

iii. a joining material bonded between the conductive layer and the metallized first surface of the ceramic layer to form a joining layer, wherein the conductive layer, the joining layer, and the metallized first surface are configured to form one or more electrically isolated conductive pads.

11. The device of claim 10 wherein the conductive layer and the joining layer are patterned to form a plurality of electrically isolated pads, further wherein each of the plurality of electrically isolated pads are electrically isolated from each other by the ceramic layer.

12. The device of claim 10 wherein the ceramic layer further comprises a metallized second surface, and the ceramic assembly further comprises a second conducive layer and a second joining material bonded between the second conductive layer and the metallized second surface of the ceramic layer to form a second joining layer.

13. The device of claim 12 further comprising a metal-to-metal joining layer bonded between the second conductive layer of the ceramic assembly and the heat exchanging device.

14. The device of claim 10 wherein the conductive layer and the heat exchanging device are copper-based.

15. The device of claim 10 wherein the ceramic layer comprises beryllium oxide, aluminum oxide, or aluminum nitride.

16. The device of claim 10 wherein the metallized first surface comprises molybdenum manganese and nickel.

17. The device of claim 10 further comprising a second thermally conductive ceramic assembly thermally coupled to an opposite side of the heat exchanging device than the ceramic assembly.

18. The device of claim 10 wherein the joining material comprise a copper-silver paste, a copper-gold paste, a copper-silver foil, or a copper-gold foil.

19. The device of claim 10 wherein the joining material and the conductive layer comprise a silver plated copper sheet.

20. A device comprising:

a. a heat exchanging device comprising a thermally conductive material, wherein the heat exchanging device is configured to transfer heat from the thermally conductive material to a fluid flowing therethrough; and

b. a thermally conductive ceramic assembly thermally coupled to the heat exchanging device, wherein the ceramic assembly comprises;

i. a ceramic layer including a metallized first surface; and

ii. a conductive layer plated to the metallized first surface, wherein the conductive layer and the metallized first surface are configured to form one or more electrically isolated conductive pads.

21. The device of claim 20 wherein the conductive layer and the metallized first surface are patterned to form a plurality of electrically isolated pads, further wherein each of the plurality of electrically isolated pads are electrically isolated from each other by the ceramic layer.

22. The device of claim 20 wherein the ceramic layer further comprises a metallized second surface, and the ceramic assembly further comprises a second conductive layer plated to the metallized second surface.

23. The device of claim 22 further comprising a metal-to-metal joining layer bonded between the second conductive layer of the ceramic assembly and the heat exchanging device.

24. The device of claim 20 wherein the conductive layer and the heat exchanging device are copper-based.

25. The device of claim 20 wherein the ceramic layer comprises beryllium oxide, aluminum oxide, or aluminum nitride.

26. The device of claim 20 wherein the metallized first surface comprises molybdenum manganese and nickel.

27. The device of claim 20 further comprising a second thermally conductive ceramic assembly thermally coupled to an opposite side of the heat exchanging device than the ceramic assembly.