Microcapsules adapted to rupture in a magnetic field to enable easy removal of one substrate from another for enhanced reworkability

Patent metadata

Field	Value
Publication number	US-9434133-B2
Application number	US-201514930336-A
Country	US
Kind code	B2
Filing date	Nov 2, 2015
Priority date	Aug 5, 2011
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

An enhanced thermal interface material (TIM) gap filler for filling a gap between two substrates (e.g., between a coldplate and an electronics module) includes microcapsules adapted to rupture in a magnetic field. The microcapsules, which are distributed in a TIM gap filler, each have a shell that encapsulates a solvent. One or more organosilane-coated magnetic nanoparticles is/are covalently bound into the shell of each microcapsule. In one embodiment, (3-aminopropyl) trimethylsilane-coated magnetite nanoparticles are incorporated into the shell of a urea-formaldehyde (UF) microcapsule during in situ polymerization. To enable easy removal of one substrate affixed to another substrate by the enhanced TIM gap filler, the substrates are positioned within a magnetic field sufficient to rupture the microcapsule shells through magnetic stimulation of the organosilane-coated magnetic nanoparticles. The ruptured microcapsule shells release the solvent, which dissolves and/or swells the TIM gap filler, thereby reducing the bond strength between the substrates.

First claim

What is claimed is:

1. An apparatus, comprising:
a first substrate;
a second substrate;
an enhanced thermal interface (TIM) gap filler disposed in a gap between the first substrate and the second substrate, wherein the enhanced TIM gap filler comprises a TIM gap filler and microcapsules distributed in the TIM gap filler, wherein each microcapsule has a shell encapsulating a solvent and into which one or more organosilane-coated magnetic nanoparticles is/are covalently bound.

2. The apparatus as recited in claim 1 , wherein the first substrate is a coldplate and the second substrate is an electronics module.

3. The apparatus as recited in claim 2 , wherein the microcapsules include urea-formaldehyde (UF) microcapsules each having a shell into which one or more (3-aminopropyl) trimethylsilane-coated magnetite nanoparticles is/are covalently bound.

4. The apparatus as recited in claim 3 , wherein the shell of each UF microcapsule encapsulates toluene.

5. The apparatus as recited in claim 3 , wherein the solvent is selected to dissolve and/or swell the TIM gap filler when the solvent is released from encapsulation upon rupture of the microcapsules in a magnetic field.

6. An apparatus, comprising:
a coldplate;
an electronics module;
an enhanced thermal interface (TIM) gap filler disposed in a gap between the coldplate and the electronics module, wherein the enhanced TIM gap filler comprises a TIM gap filler and microcapsules distributed in the TIM gap filler, wherein each microcapsule has a shell encapsulating a solvent and into which one or more organosilane-coated magnetic nanoparticles is/are covalently bound so that the one or more organosilane-coated magnetic nanoparticles is/are embedded in the shell of each of the microcapsules.

7. The apparatus as recited in claim 6 , wherein the microcapsules include urea-formaldehyde (UF) microcapsules each having a shell into which one or more (3-aminopropyl) trimethylsilane-coated magnetite nanoparticles is/are covalently bound.

8. The apparatus as recited in claim 7 , wherein the shell of each UF microcapsule encapsulates toluene.

9. The apparatus as recited in claim 7 , wherein the solvent is selected to dissolve and/or swell the TIM gap filler when the solvent is released from encapsulation upon rupture of the microcapsules in a magnetic field.

10. An apparatus, comprising:
a coldplate;
an electronics module;
an enhanced thermal interface (TIM) gap filler disposed in a gap between the coldplate and the electronics module, wherein the enhanced TIM gap filler comprises a TIM gap filler and urea-formaldehyde (UF) microcapsules distributed in the TIM gap filler, wherein each UF microcapsule has a shell encapsulating a solvent and into which one or more (3-aminopropyl) trimethylsilane-coated magnetite nanoparticles is/are covalently bound so that the one or more (3-aminopropyl) trimethylsilane-coated magnetite nanoparticles is/are embedded in the shell of each of the UF microcapsules.

11. The apparatus as recited in claim 10 , wherein the shell of each UF microcapsule encapsulates toluene.

12. The apparatus as recited in claim 10 , wherein the solvent is selected to dissolve and/or swell the TIM gap filler when the solvent is released from encapsulation upon rupture of the microcapsules in a magnetic field.

Assignees

• IBM

Inventors

• Boday Dylan J
• Kuczynski Joseph
• Meyer Iii Robert E

Classifications

• B32B9/04 Primary

  comprising such {particular} substance as the main or only constituent of a layer, {which is} next to another layer of {the same or of} a {different material (next to a glass layer B32B17/06; layered products with at least two ceramic layers composed mainly of ceramic B32B18/00)} · CPC title

• B01J13/18 Primary

  In situ polymerisation with all reactants being present in the same phase · CPC title

• Y10T156/1111

  Using solvent during delaminating [e.g., water dissolving adhesive at bonding face during delamination, etc.] · CPC title

• Y10T428/31663

  As siloxane, silicone or silane · CPC title

• C09K5/08

  Materials not undergoing a change of physical state when used (C09K5/16, C09K5/20 take precedence) · CPC title