Cooling assembly comprising micro-jets

• US 7,483,770 B2
• Filed: 02/09/2004
• Issued: 01/27/2009
• Est. Priority Date: 02/20/2003
• Status: Expired due to Fees

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Nicole, Celine Catherine Sarah, Meinders, Erwin Rinaldo
• Primary Examiner(s): Decady; Albert
• Assistant Examiner(s): Lee; Douglas S
• Application Number:
  US10/545,987
• Publication Number:
  US 20060164805A1
• Time in Patent Office: 1,814 Days
• Field of Search: 700/300, 156/345, 156/640, 361/382, 361/385, 361/699, 621/71, 622/592
• US Class Current: 700/300
• CPC Class Codes: H01L 23/4735 Jet impingement H01L23/4336 takes precedence
• 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

Abstract

A cooling assembly for cooling a heat source, such an electronic components, with a coolant includes micro jets adapted to eject the coolant onto the heat source in response to a control signal, and a controller adapted to control the ejection of the coolant from the micro jets in a sweep mode in which the micro jets eject the coolant sequentially. The micro jets may be arranged as an array and the coolant is forced induce velocity perturbations of the coolant, to avoid the occurrence of free circulation areas in the cooling channel, and to obtain a microscopic transport of the cooling through the cooling channel.

Claims

1. A cooling assembly for cooling a heat source with a coolant comprising:

a plurality of micro jets adapted for ejection of the coolant onto the heat source in response to a control signal, and

a controller adapted to control the ejection of the coolant from the micro-jets,

said controller being configured to control the ejection of the coolant from the micro jets in a sweep mode where the coolant is swept across the heat source such that local hot spots of the heat source with lower heat transfer rates are reduced to prevent formation of heat transfer minimum and maximum across the heat source, wherein the micro jets are placed at an inclined angle with respect to a surface of the heat source.

2. The cooling assembly as claimed in claim 1, wherein the micro jets comprise:

an inlet for inflow of the coolant,

an outlet for ejection of the coolant,

a micro-channel for flow of the coolant from the inlet to the outlet, and

a forcing means for inducing velocity perturbations on the coolant in the micro-channel,

wherein the micro-jets are arranged substantially perpendicular to the surface of the heat source.

3. The cooling assembly as claimed in claim 2, wherein said forcing means comprises a piezoelectric crystal, piezoelectric ceramics or a woofer and a controller for controlling the forcing.

4. The cooling assembly as claimed in claim 1, wherein the coolant is a fluid, in particular water, or a gas, in particular air or nitrogen.

8. The cooling assembly as claimed in claim 1, wherein the plurality of micro jets is arranged as a two-dimensional array of micro jets.

12. The cooling assembly as claimed in claim 1, wherein the controller is further adapted to control the micro jets such that the micro jets eject a bias amount of coolant continuously according to a bias flow rate and eject a higher amount of coolant during a predetermined time period according to an additional flow rate, the higher amount being superimposed over the bias amount.

13. The cooling assembly as claimed in claim 1, wherein the controller is further adapted for controlling the micro jets such that only during predetermined time periods coolant is ejected.

14. A semiconductor device, comprising:

a semiconductor element and

the cooling assembly as claimed in claim 1 integrated with the semiconductor element for cooling the semiconductor element.

15. A circuit board, comprising:

a semiconductor device and

the cooling assembly as claimed in claim 1 arranged to cool the semiconductor device.

19. The cooling assembly as claimed in claim 1, wherein the micro-jets are placed at an inclined angle with respect to the heat source in the range from about 0°

to about 45°

.

20. The cooling assembly of claim 1, wherein the controller is further configured to control the ejection of the coolant from the micro jets in a sweep mode in which the micro jets eject the coolant sequentially.

21. The cooling assembly of claim 1, wherein the controller is further configured to reduce re-circulation of the coolant in the cooling channel and flow separation across the heat source.

22. The cooling assembly of claim 1, wherein the controller is further configured to superimpose a bias amount of coolant for continuous discharge from the plurality of micro jets over the ejection of the coolant in the sweep mode where coolant of larger quantity than the bias amount is sequentially ejected from plurality of micro jets to direct the coolant in at least one desired direction.

5. A cooling assembly for cooling a heat source with a coolant comprising:

a plurality of micro jets adapted for ejection of the coolant onto the heat source in response to a control signal, and

a controller adapted to control the ejection of the coolant from the micro-jets,

said controller being configured to control the ejection of the coolant from the micro jets in a sweep mode where the coolant is swept across the heat source such that local hot spots of the heat source with lower heat transfer rates are reduced to prevent formation of heat transfer minimum and maximum across the heat source,

wherein the micro jets comprise;

an inlet for inflow of the coolant,

an outlet for ejection of the coolant,

a micro-channel for flow of the coolant from the inlet to the outlet, and

a forcing means for inducing velocity perturbations on the coolant in the micro-channel and

wherein the forcing frequency of the forcing means is in a frequency range below 200 Hz or above 10 kHz.

6. A cooling assembly for cooling a heat source with a coolant comprising:

a plurality of micro jets adapted for ejection of the coolant onto the heat source in response to a control signal, and

a controller adapted to control the ejection of the coolant from the micro-jets,

said controller being configured to control the ejection of the coolant from the micro jets in a sweep mode where the coolant is swept across the heat source such that local hot spots of the heat source with lower heat transfer rates are reduced to prevent formation of heat transfer minimum and maximum across the heat source,

wherein the micro jets comprise;

an inlet for inflow of the coolant,

an outlet for ejection of the coolant, and

a micro-channel for flow of the coolant from the inlet to the outlet,

wherein the diameter of the micro-channels is in the range from about 10 μ

m to about 10 mm.

17. The cooling assembly as claimed in claim 6, wherein the diameter of the micro-channels is in the range from about 50 μ

m to about 5 mm.

7. A cooling assembly for cooling a heat source with a coolant comprising:

a plurality of micro jets adapted for ejection of the coolant onto the heat source in response to a control signal, and

a controller adapted to control the ejection of the coolant from the micro-jets,

said controller being configured to control the ejection of the coolant from the micro jets in a sweep mode where the coolant is swept across the heat source such that local hot spots of the heat source with lower heat transfer rates are reduced to prevent formation of heat transfer minimum and maximum across the heat source,

wherein the micro jets comprise;

an inlet for inflow of the coolant,

an outlet for ejection of the coolant, and

a micro-channel for flow of the coolant from the inlet to the outlet,

wherein the distance of the outlet of the micro jets from the surface of the heat source is in the range from about 0.1 mm to about 20 mm.

18. The cooling assembly as claimed in claim 7, wherein the distance of the outlet of the micro-jets from the surface of the heat source is in the range from about 0.5 mm to about 10 mm.

9. A cooling assembly for cooling a heat source with a coolant comprising:

a plurality of micro jets adapted for ejection of the coolant onto the heat source in response to a control signal, and

a controller adapted to control the ejection of the coolant from the micro-jets,

said controller being configured to control the ejection of the coolant from the micro jets in a sweep mode where the coolant is swept across the heat source such that local hot spots of the heat source with lower heat transfer rates are reduced to prevent formation of heat transfer minimum and maximum across the heat source,

wherein the plurality of micro jets is arranged as a two-dimensional array of micro jets, and

wherein the controller is further adapted for controlling the ejection of the coolant such that the coolant is subsequently ejected from a central to outer micro jets or vice versa.

10. A cooling assembly for cooling a heat source with a coolant comprising:

a plurality of micro jets adapted for ejection of the coolant onto the heat source in response to a control signal, and

a controller adapted to control the ejection of the coolant from the micro-jets,

said controller being configured to control the ejection of the coolant from the micro jets in a sweep mode where the coolant is swept across the heat source such that local hot spots of the heat source with lower heat transfer rates are reduced to prevent formation of heat transfer minimum and maximum across the heat source,

wherein the plurality of micro jets is arranged as a two-dimensional array of micro jets, and

wherein the controller is further adapted for controlling the ejection of the coolant such that the coolant is alternately ejected from micro jets in even and odd rows or columns.

11. A cooling assembly for cooling a heat source with a coolant comprising:

a plurality of micro jets adapted for ejection of the coolant onto the heat source in response to a control signal, and

a controller adapted to control the ejection of the coolant from the micro-jets,

said controller being configured to control the ejection of the coolant from the micro jets in a sweep mode where the coolant is swept across the heat source such that local hot spots of the heat source with lower heat transfer rates are reduced to prevent formation of heat transfer minimum and maximum across the heat source,

wherein the plurality of micro jets is arranged as a two-dimensional array of micro jets, and

wherein the controller is further adapted for controlling the ejection of the coolant such that the flow of ejected coolant is forced into a predetermined direction.

16. A cooling method for cooling a heat source, in electronic components, with a coolant, comprising the acts of:

ejecting the coolant onto the heat source in response to a control signal using a plurality of micro jets placed at an inclined angle with respect to a surface of the heat source, and

controlling the ejecting act in a sweep mode where the coolant is swept across the heat source such that local hot spots of the heat source with lower heat transfer rates are reduced to prevent formation of heat transfer minimum and maximum across the heat source.