Variable thickness heat pipe

1. A cooling assembly, comprising:

a heat spreader;

a radiator;

and a heat pipe coupling the heat spreader and the radiator, the heat pipe having a midline therealong, the heat pipe including:

a first end portion extending longitudinally along the midline and connected to the heat spreader, the first end portion having a first thickness,

a second end portion extending longitudinally along the midline, the second end portion being connected to the radiator, the second end portion having a second thickness, and

a mid-portion extending longitudinally along the midline, the mid-portion being located between the first end portion and the second-end portion, and the mid-portion having a third thickness that is greater than the first thickness and the second thickness.

2. The cooling assembly of claim 1 , wherein the first end portion, the second end portion, and the mid-portion have a uniform width.

3. The cooling assembly of claim 1 , wherein the first end portion, the second end portion, and the mid-portion are arranged co-linearly.

4. The cooling assembly of claim 1 , wherein the first thickness is equal to 1L mm, the second thickness is equal to 1.5L mm, and the third thickness is equal to 1.3L mm, wherein L is an integer greater than or equal to 1.

5. The cooling assembly of claim 1 , wherein the heat pipe further includes a casing having a uniform wall thickness and a wick enclosed in the casing.

6. The cooling assembly of claim 1 , wherein the heat pipe further includes a casing having a variable wall thickness and a wick enclosed in the casing, wherein the casing has a greater wall thickness in the mid-portion of the heat pipe than in the either one of the first end portion and the second end portion.

7. The cooling assembly of claim 1 , wherein:

the first end portion is disposed on a surface of the heat spreader;

the first end portion extends substantially up to an edge of the heat spreader where the surface ends; and

the mid-portion juts below the edge of the heat spreader starting at a location on the heat pipe where the first end portion ends and the mid-portion begins.

8. The cooling assembly of claim 1 , wherein the second thickness of the second end portion is greater than the first thickness of the first end portion.

9. An apparatus comprising:

an enclosure having a first face and a second face opposite the first face;

a heat-generating component disposed inside the enclosure between the first face and the second face;

a radiator disposed inside the enclosure between the first face and the second face;

a heat spreader that is in thermal contact with the heat generating component, the heat spreader being disposed between the heat generating component and the top face; and

a heat pipe including:

a first end portion extending longitudinally along the midline and connected to the heat spreader, the first-end portion being disposed on the heat spreader and between the heat spreader and the first face, the first end portion having a first thickness,

a second end portion extending longitudinally along the midline, the second end portion being connected to the radiator, and the second end portion having a second thickness, and

a mid-portion extending longitudinally along the midline, the mid-portion connecting the first end portion and the second-end portion, the mid-portion having a third thickness that is greater than either one of the first thickness and the second thickness.

10. The apparatus of claim 9 , wherein the first end portion, the second end portion, and the mid-portion have a uniform width.

11. The apparatus of claim 9 , wherein the first end portion, the second end portion, and the mid-portion are co-linear.

12. The apparatus of claim 9 , wherein the first thickness is equal to 1L mm, the second thickness is equal to 1.5L mm, and the third thickness is equal to 1.3L mm, wherein L is an integer greater than or equal to 1.

13. The apparatus of claim 9 , wherein the heat pipe further includes a casing having a uniform wall thickness and a wick enclosed in the casing.

14. The apparatus of claim 13 , wherein the casing has a greater wall thickness in the mid-portion of the heat pipe than in the either one of the first end portion and the second end portion.

15. The apparatus of claim 9 , wherein:

the first end portion is disposed on a surface of the heat spreader;

the first end portion extends substantially upto an edge of the heat spreader where the surface ends; and

the mid-portion juts below the edge of the heat spreader starting at a location on the heat pipe where the first end portion ends and the mid-portion begins.

16. The apparatus of claim 9 , wherein the second thickness of the second end portion is greater than the first thickness of the first end portion.

17. An apparatus comprising:

an enclosure having a first face and a second face opposite the first face;

a circuit board disposed between the first face and the second face;

one or more integrated circuits mounted on the circuit board;

a heat spreader disposed on at least some of the one or more integrated circuits;

a radiator disposed inside the enclosure between the first face and the second face; and

a heat pipe disposed between the first face and the second face, the heat pipe having a midline therealong, the heat pipe including:

a first end portion connected to the radiator, the first end portion extending longitudinally along the mid-line;

a second end portion connected to the heat spreader, the second end portion extending longitudinally along the mid-line; and

a mid-portion connecting the first end portion and the second portion, the mid-portion extending longitudinally along the mid-line, and the mid-portion extending further towards a surface of the circuit board than the first end portion and the second end portion.

18. The apparatus of claim 17 , wherein the mid-portion extends a same distance away from the surface of the circuit board as the first end portion and the second end portion.

19. The apparatus of claim 17 , wherein the mid-portion extends a same distance in a direction parallel to the surface of the circuit board as the first end portion and the second end portion.

20. The apparatus of claim 17 , wherein the heat pipe further includes:

a casing that defines the first end portion, the second end portion, and the mid-portion, the casing having a uniform wall thickness, and

a wick enclosed in the casing.