Device and System for Dissipating Heat, and Method of Making Same
A device and system for dissipating heat includes a bent portion of pyrolytic graphite in which a-b planes at a center region of the bent portion follow a surface contour of the bent portion. A method for making a heat dissipating device includes bending a flat sheet of pyrolytic graphite such that a-b planes at a center region of a bent portion follow a surface contour of the bent portion.
1 . A device for dissipating heat from a heat source, the device comprising:
a sheet including a flat first portion and a bent second portion integrally formed on the first portion, wherein each of the first portion and the second portion has a core substrate that consists essentially of pyrolytic graphite, and a-b planes of the pyrolytic graphite at a center region of the first portion and the second portion follow a surface contour of the first portion and the second portion.
2 . The device of claim 1 , wherein the a-b planes at the center region of the second portion have a bend angle of at least 15°.
3 . The device of claim 1 , wherein the sheet further includes a flat third portion integrally formed on the second portion, the third portion consists essentially of pyrolytic graphite, and central a-b planes of the pyrolytic graphite running between the first portion and the third portion bend at least 15°.
4 . The device of claim 3 , wherein the sheet further includes a curved fourth portion integrally formed on the third portion, the fourth portion consists essentially of pyrolytic graphite, and a-b planes at a center region of the fourth portion have a bend angle of at least 15°.
5 . The device of claim 1 , further comprising a cover disposed over any one or more of the portions of the sheet.
6 . The device of claim 5 , wherein the cover includes two opposing layers, and any one or more of the portions of the sheet is or are disposed between the two opposing layers.
7 . The device of claim 5 , wherein all the portions of the sheet are sealed within the cover.
8 . The device of claim 5 , wherein the cover includes a metal foil.
9 . The device of claim 5 , wherein the cover includes a polymer layer having a greater dielectric resistance relative to underlying material beneath the polymer layer.
10 . The device of claim 5 , wherein the cover includes a metal mesh configured to accommodate a difference in thermal expansion between the sheet and a heat source to be thermally coupled to the sheet.
11 . A system for dissipating heat, the system comprising:
the device of claim 1 ; and
a heat source thermally coupled to the device.
12 . A method for making a heat dissipating device, the method comprising:
bending a sheet of pyrolytic graphite to form a bent portion, wherein a-b planes of the pyrolytic graphite at a center region of the bent portion follow a curved surface contour of the bent portion.
13 . The method of claim 12 , wherein the bending step includes bending central a-b planes at least 15°.
14 . The method of claim 12 , wherein after the bending step, two portions of the sheet are flat, and the bent portion is disposed between the two portions.
15 . The method of claim 14 , wherein the two flat portions are offset and parallel to each other.
16 . The method of claim 14 , wherein a-b planes at center regions of the two flat portions are flat, and the a-b planes at the center region of the bent portion are curved.
17 . The method of claim 12 , wherein the bending step includes one or both of roll forming and press forming.
18 . The method of claim 12 , further comprising applying a cover over the bent portion or another portion of the sheet.
19 . The method of 18 , wherein the cover includes any one or more of a metal layer portion, a polymer layer portion, and a mesh portion.
20 . The method of claim 18 , wherein at least one portion of the cover is applied during the bending step.