Thermal interface materials using metal nanowire arrays and sacrificial templates

Patent metadata

Field	Value
Publication number	US-2016251769-A1
Application number	US-201615006597-A
Country	US
Kind code	A1
Filing date	Jan 26, 2016
Priority date	Feb 26, 2015
Publication date	Sep 1, 2016
Grant date	—

Abstract

A method for making a thermal interface material (TIM) comprises the steps of: depositing a seed layer onto a substrate; attaching a template membrane to the substrate; depositing metal into one or more of the pores of the template membrane, substantially filling the template membrane to create a vertically-aligned metal nanowire (MNW) array comprising a plurality of nanowires that grow upward from the seed layer; and after the template membrane is substantially filled with the deposited metal, removing the template membrane, leaving the plurality of nanowires attached to the seed layer. A TIM comprises: a vertically-aligned MNW array comprising a plurality of nanowires that grow upward from a seed layer deposited on the surface of a template membrane, and the template membrane being removed after MNW growth.

First claim

What is claimed is:

1 . A method for making a thermal interface material (TIM), comprising the steps of:
depositing a seed layer onto a substrate; attaching a sacrificial porous template membrane to the substrate; depositing metal into one or more of the pores of the template membrane, substantially filling the template membrane to create a vertically-aligned metal nanowire (MNW) array comprising a plurality of nanowires that grow upward from the seed layer; and after the template membrane is substantially filled with the deposited metal, removing the template membrane, leaving the plurality of nanowires attached to the seed layer.

2 . The method of claim 1 , wherein the template membrane is subfilled, generating a one-sided array.

3 . The method of claim 1 , wherein the template membrane is superfilled, generating a two-sided array.

4 . The method of claim 3 , further comprising an additional step, performed after the metal depositing step and prior to the removing step, of:
mechanically peeling off a substantially continuous overplated film deposited above the pores in the depositing step, thereby converting the superfilled, two-sided MNW array to a one-sided MNW array.

5 . The method of claim 2 , comprising a further step, performed after the removing step, of:
electrodepositing additional metal to extend growth from the tips of the nanowires to make the MNW array thicker than the template membrane.

6 . The method of claim 1 , wherein: the template membrane comprises one or more of a ceramic template membrane and a polymer template membrane.

7 . The method of claim 1 , further comprising a step, performed after the removing step, of:
infiltrating the MNWs with an interstitial material to form a composite.

8 . The method of claim 7 , wherein the interstitial material comprises one or more of a phase change material (PCM) and a polymer.

9 . The method of claim 1 , further comprising an additional step, performed after the removing step, of applying a post-growth treatment to the MNW array.

10 . The method of claim 9 , wherein the post-growth treatment comprises applying to the MNWs one or more of a protective anti-oxidation coating and a protecting anti-oxidation film.

11 . The method of claim 10 , wherein the anti-oxidation coating comprises one or more of nickel, cobalt, platinum, rhodium, palladium, iridium, another noble metal, and a protective oxide.

12 . A method for making a thermal interface material (TIM), comprising the steps of:
depositing a seed layer onto a sacrificial porous template membrane; thickening the seed layer; depositing metal into one or more of the pores of the template membrane, substantially filling the template membrane to create a vertically-aligned metal nanowire (MNW) array comprising a plurality of nanowires that grow upward from the seed layer; and after the template membrane is substantially filled with the deposited metal, removing the template membrane, leaving the plurality of nanowires attached to the seed layer.

13 . A method for making a thermal interface material (TIM), comprising the steps of:
depositing a seed layer that functions as a cathode onto a sacrificial porous template membrane; attaching a sacrificial porous template membrane to the substrate; electrodepositing metal into one or more of the pores of the template membrane, substantially filling the template membrane to create a vertically-aligned metal nanowire (MNW) array comprising a plurality of nanowires that grow upward from the seed layer; electrodepositing additional metal to extend growth from the tips of the nanowires to make the MNW array thicker than the template membrane; and after the template membrane is substantially filled with the electrodeposited metal, removing the template membrane, leaving the plurality of nanowires attached to the seed layer.

14 . The method of claim 13 , wherein the plating solution comprises an electrolyte configured to prevent one or more of bulk movement and convective motion of the plating solution.

15 . A method for making a thermal interface material (TIM), comprising the steps of:
depositing a seed layer that functions as a cathode onto a sacrificial porous template membrane; thickening the seed layer; electrodepositing metal into one or more of the pores of the template membrane, substantially filling the template membrane to create a vertically-aligned metal nanowire (MNW) array comprising a plurality of nanowires that grow upward from the seed layer; electrodepositing additional metal to extend growth from the tips of the nanowires to make the MNW array thicker than the template membrane; and after the template membrane is substantially filled with the electrodeposited metal, removing the template membrane, leaving the plurality of nanowires attached to the seed layer.

16 . A thermal interface material (TIM) comprising:
a vertically-aligned metal nanowire (MNW) array comprising a plurality of nanowires that grow upward from a seed layer deposited onto a template membrane using a vat comprising a growing medium, and the template membrane being removed after MNW growth.

17 . The TIM of claim 16 , wherein the growing medium comprises one or more of a plating solution, an electroless solution, and an ionic liquid.

18 . The TIM of claim 16 , wherein the vat comprises one or more of an electrochemical vat and an electroless vat.

19 . The TIM of claim 16 , further comprising an interstitial material with which the MNWs are infiltrated to form a composite.

20 . The TIM of claim 19 , wherein the interstitial material comprises one or more of a phase change material (PCM) and a polymer.

21 . The TIM of claim 16 , further comprising a protective anti-oxidation coating added after removal of the template membrane.

22 . The TIM of claim 21 , wherein the anti-oxidation coating comprises one or more of nickel, cobalt, platinum, rhodium, palladium, iridium, and another noble metal.

23 . The TIM of claim 16 , further comprising additional metal electrodeposited to extend growth from the tips of the nanowires to make the MNW array thicker than the template membrane.

24 . The TIM of claim 18 , wherein the vat comprises an electrochemical vat, and wherein the electrochemical vat comprises a plating solution, and wherein the plating solution comprises an electrolyte configured to prevent one or more of bulk movement and convective motion of the plating solution.

25 . The TIM of claim 24 , wherein the electrolyte comprises one or more of a gel electrolyte and a simple liquid ionized salt solution with dissolved ions.

Assignees

• Northrop Grumman Systems Corp
• Univ Leland Stanford Junior

Inventors

• Silverman Edward M
• Starkovich John A
• Peng Hsiao-Hu
• Tice Jesse B
• Barako Michael T
• Coyan Conor E
• Goodson Kenneth E

Classifications

• H10W40/258

  Metallic materials (H10W40/254, H10W40/257, H10W40/255, H10W40/251, H10W40/253 take precedence) · CPC title

• H10W40/251

  Organics · CPC title

• H10W40/25 Primary

  characterised by their materials · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• C25D1/04

  Wires; Strips; Foils · CPC title