Micro-structured cooler and use thereof
View Patent ↗For providing a particularly efficient micro-structured cooler intended more specifically for cooling electronic components, it is proposed to proceed in the following manner to build this cooler: providing a stack of at least two metal foils ( 1 ) comprising channels ( 2 ) for coolant and one base plate ( 5 ) adapted to be brought into thermal contact with the electronic component ( 4 ) through a thermal contact surface ( 6 ), said metal foils ( 1 ) and said base plate ( 5 ) being joined together so as to form a single piece of material, said channels ( 2 ) having a width b ranging from 100 to 350 μm, a depth t ranging from 30 to 150 μm, a mean spacing s ranging from 30 to 300 μm, residual foil thickness r remaining after formation of the channels ( 2 ) in the metal foils ( 1 ) ranging from 30 to 300 μm and said base plate ( 5 ) having a thickness g ranging from 100 to 1,000 μm.
1. A micro-structured cooler ( 3 ) for an item ( 4 ) to be cooled, comprising
a. a stack of at least two metal foils ( 1 ), said foils having channels ( 2 ) for coolant, and of one base plate ( 5 ) adapted to be brought into thermal contact with said item ( 4 ) through a thermal contact surface ( 6 ), said metal foils ( 1 ) and said base plate ( 5 ) being joined together so as to form a single piece of material, said channels ( 2 ) having a width b ranging from 100 to 350 μm, a depth t ranging from 30 to 150 pm, a mean spacing s ranging from 30 to 300 μm, a residual foil thickness r remaining after formation of said channels ( 2 ) in said metal foils ( 1 ) ranging from 30 to 300 pm and said base plate ( 5 ) having a thickness g ranging from 100 to 1,000 μm,
b. at least one splitting chamber ( 10 ) traversing said metal foils ( 1 ) approximately in the region of said thermal contact surface ( 6 ), said chamber communicating with a respective inlet-side end of all or of selected channels ( 2 ) through channel inlet ports,
c. at least one inlet chamber ( 20 ) for admission of coolant into said cooler ( 3 ), said chamber communicating with said at least one splitting chamber ( 10 ),
d. at least one collecting chamber ( 11 ) traversing the metal foils ( 1 ) and communicating with a respective outlet-side end of all or selected channels ( 2 ) through channel outlet ports and
a at least one outlet chamber ( 21 ) for discharging coolant from said cooler ( 3 ), said chamber communicating with said at least one collecting chamber ( 11 ),
characterized in that the cross sectional area of the channels ( 2 ) in a channel layer adjacent said base plate ( 5 ) is greater than the cross sectional area of the channels ( 2 ) in a channel layer located in the stack on the side opposite said base plate ( 5 ).
2. The cooler as set forth in claim 1 , characterized in that the depth of the channels ( 2 ) in a channel layer adjacent said base plate ( 5 ) is greater than the depth of the channels ( 2 ) in a channel layer located in the stack on the side opposite said base plate ( 5 ).
3. The cooler as set forth in claim 1 , characterized in that a first metal foil ( 1 ′) adjacent the base plate ( 5 ) and said base plate ( 5 ) are provided with channels ( 2 ′) and joined together in such a manner that the surfaces of said first metal foil ( 1 ′) and of said base plate ( 5 ) comprising the channels are facing each other and that said channels ( 2 ′) in said first metal foil ( 1 ′) and in said base plate ( 5 ) coincide.
4. The cooler as set forth in claim 3 , characterized in that the depth t of the channels formed by joining the first metal foil ( 1 ′) and the base plate ( 5 ) range from 100 to 250 μm.
5. The cooler as set forth in claim 1 , characterized in that the at least one inlet chamber ( 20 ) tapers toward the at least one splitting chamber ( 10 ) and that the at least one outlet chamber ( 21 ) tapers toward the at least one collecting chamber ( 11 ).
6. The cooler as set forth in claim 1 , characterized in that the at least one inlet chamber ( 20 ) tapers to an outlet side width x, that the at least one splitting chamber ( 10 ) has a width b 10 and that x≧b 10 .
7. The cooler as set forth in claim 1 , characterized in that the at least one outlet chamber ( 21 ) tapers to an inlet side width y, that the at least one collecting chamber ( 11 ) has a width b 11 and that y≧b 11 .
8. The cooler as set forth in claim 1 , characterized in that said cooler further has at least one inlet neck ( 15 ) for admitting coolant into the cooler ( 3 ), that the at least one inlet chamber ( 20 ) has an inlet-side width m and that m is at the most equal to the width of the cross section of the at least one inlet neck ( 15 ).
9. The cooler as set forth in claim 1 , characterized in that it further has an outlet neck ( 16 ) for discharging coolant from the cooler ( 3 ), that the at least one outlet chamber ( 21 ) has an outlet-side width n and that n does not exceed the width of the cross section of the at least one outlet neck ( 16 ).
10. The cooler as set forth in claim 1 , characterized in that the at least one splitting chamber ( 10 ) is configured to be a gap traversing the metal foils ( 1 ) and having a width b 10 .
11. The cooler as set forth in claim 1 , characterized in that the at least one collecting chamber ( 11 ) is configured to be a gap traversing the metal foils ( 1 ) and having a width b 11 .
12. The cooler as set forth in claim 1 , characterized in that, in a respective end region located on the inlet side and extending over a length E, the channels ( 2 ) are enlarged toward the at least one splitting chamber ( 10 ).
13. The cooler as set forth in claim 12 , characterized in that the ratio spacing k between the channel inlet ports to channel width b ranges from 1.1 through 3.
14. The cooler as set forth in claim 12 , characterized in that the ratio spacing k between the channel inlet ports to channel width b ranges from 1.2 through 1.8.
15. The cooler as set forth in claim 12 , characterized in that the length E ranges from 100 through 2,000 μm.
16. The cooler as set forth in claim 12 , characterized in that the length E ranges from 200 through 400 μm.
17. The cooler as set forth in claim 1 , characterized in that a ratio channel width b to mean spacing s of the channels ( 2 ) ranges from 1.5:1 through 2.5:1.
18. The cooler as set forth in claim 1 , characterized in that a ratio channel width b to residual foil thickness r ranges from 2:1 through 5:1.
19. The cooler as set forth in claim 1 , characterized in that the width b of the channels ( 2 ) ranges from 200 through 300 μm.
20. The cooler as set forth in claim 1 , characterized in that the depth t of the channels ( 2 ) ranges from 50 through 120 μm.
21. The cooler as set forth in claim 1 characterized in that the mean spacing s between the channels ( 2 ) ranges from 150 through 300 μm.
22. The cooler as set forth in claim 1 , characterized in that the residual foil thickness r ranges from 50 through 120 μm.
23. The cooler as set forth in claim 1 , characterized in that the thickness g of the base plate ( 5 ) ranges from 300 through 500 μm.
24. The cooler as set forth in claim 1 , characterized in that the channels ( 2 ) in the metal foils ( 1 ) form a heat exchange surface that is greater than the thermal contact surface ( 6 ).