Compliant thermal interface for electronic equipment
View Patent ↗A thin metallic sheet having an array of alternating domes, directed away from opposite sides of the sheet, to bridge a gap between a top surface of a processor package and a bottom surface of a heat sink. The sheet is positioned between the processor package and heat sink before securing the heat sink to the processor package. By pressing the processor package and heat sink together, the tops of the domes flatten out to maximize surface contact between a first side of the sheet and the top of the processor package, and between a second side of the sheet and the top of the heat sink.
1. A thermal interface comprising:
a malleable sheet;
a first array of hollow domes extending away from a first side of the malleable sheet; and
a second array of hollow domes extending away from a second side of the malleable sheet, wherein the first array of hollow domes is offset to the second array of hollow domes, and wherein the malleable sheet is oriented between an electronic device and a heat sink to facilitate a transfer of heat from the electronic device to the heat sink when the thermal interface is compressed between the electronic device and the heat sink.
2. The thermal interface of claim 1 , wherein the malleable sheet is made of a compliant metal, such that the first and second arrays of hollow domes conform to irregularities between a contact surface of the electronic device and a contact surface of the heat sink when the thermal interface is compressed between the electronic device and the heat sink.
3. The thermal interface of claim 2 , wherein the compliant metal is copper.
4. The thermal interface of claim 2 , wherein the thermal interface is sandwiched between the electronic device and the heat sink in a cavity in the heat sink, such that an adhesive is not used to secure the thermal interface to the heat sink or the electronic device.
5. The thermal interface of claim 1 , wherein a dome top of each dome in the first and second arrays of hollow domes is thinner than the rest of the dome, such that the dome top is more malleable when crushed than the rest of the dome in order to provide greater surface contact between the thermal interface and the electronic device or the heat sink.
6. The thermal interface of claim 1 , wherein a dome top of each dome in the first and second arrays of hollow domes includes at least one slit, such that the dome top is more malleable when crushed than the rest of the dome in order to provide greater surface contact between the thermal interface and the electronic device or heat sink.
7. The thermal interface of claim 1 , wherein the electronic device is a microprocessor mounted on a circuit board.
8. The thermal interface of claim 1 , wherein a peak-to-peak distance from an apex of an up dome in the first array of hollow domes is between 1.6 millimeters and 2.0 millimeters to an apex of a down dome in the second array of hollow domes.
9. The thermal interface of claim 6 , wherein the at least one slit extends completely through the dome top.
10. A method comprising:
positioning a malleable sheet between an electronic device and a heat sink, the malleable sheet including:
a first array of hollow domes extending away from a first side of the sheet; and
a second array of hollow domes extending away from a second side of the sheet, wherein the first array of domes is offset to the second array of hollow domes, and wherein the malleable sheet is oriented between an electronic device and a heat sink to facilitate a transfer of heat from the electronic device to the heat sink when the malleable sheet is compressed between the electronic device and the heat sink.
11. The method of claim 10 , wherein the malleable sheet is made of a compliant metal, such that the first and second arrays of hollow domes conform to irregularities between a contact surface of the electronic device and a contact surface of the heat sink when the malleable sheet is compressed between the electronic device and the heat sink.
12. The method of claim 10 , wherein the thermal interface is sandwiched between the electronic device and the heat sink in a cavity in the heat sink, such that an adhesive is not used to secure the thermal interface to the heat sink or the electronic device.
13. The method of claim 10 , wherein a dome top of each dome in the first and second arrays of hollow domes is thinner than the rest of the dome, such that the dome top is more prone to being flattened than the rest of the dome in order to provide greater surface contact between the thermal interface and the electronic device or the heat sink when the malleable sheet is compressed between the electronic device and the heat sink.
14. The method of claim 10 , further comprising a plurality of radially extending slits in a dome top of at least one dome from the first and second arrays of domes, wherein the plurality of radially extending slits makes the dome top more malleable when crushed to promote more thorough flattening for better contact with a flat surface.
15. The method of claim 10 , wherein the electronic device is a microprocessor mounted on a circuit board.
16. The method of claim 14 , wherein the plurality of radially extending slits are in all dome tops of domes in the first and second arrays of domes, and wherein the plurality of radially extending slits extend completely through the dome tops.
17. A compliant sheet comprising:
a first array of domes extending away from a first side of the sheet;
a second array of domes extending away from a second side of the sheet, wherein the first array of domes is offset to the second array of domes; and
a plurality of radially extending slits in a dome top of at least one dome from the first and second arrays of domes, wherein the plurality of radially extending slits makes the dome top more malleable when crushed to promote more thorough flattening for better contact with a flat surface.
18. The compliant sheet of claim 17 , wherein the compliant sheet is made of a malleable metal.
19. The compliant sheet of claim 16 , wherein the plurality of radially extending slits are slits that traverse completely though the dome tops.
20. The compliant sheet of claim 18 , wherein the compliant sheet is a thermal interface that is mounted between an electronic device and a heat sink.