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-9694337-B2
Application number	US-201615207016-A
Country	US
Kind code	B2
Filing date	Jul 11, 2016
Priority date	Aug 5, 2011
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

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. A microcapsule adapted to rupture in a magnetic field, comprising:
a urea-formaldehyde (UF) microcapsule having a shell 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 the UF microcapsule, wherein the shell of the UF microcapsule encapsulates a solvent.

2. The microcapsule adapted to rupture in a magnetic field as recited in claim 1 , wherein the one or more organosilane-coated magnetic nanoparticles is/are one or more (3-aminopropyl) trimethylsilane-coated magnetite nanoparticles.

3. The microcapsule adapted to rupture in a magnetic field as recited in claim 2 , wherein the [shell of the UF microcapsule encapsulates] solvent is toluene.

4. An enhanced thermal interface material (TIM) gap filler, comprising:
a TIM gap filler; and
microcapsules adapted to rupture in a magnetic field 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 the microcapsule, and 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 the magnetic field.

5. The enhanced thermal interface (TIM) gap filler as recited in claim 4 , 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.

6. The enhanced thermal interface (TIM) gap filler as recited in claim 5 , wherein the solvent is toluene.

7. A microcapsule adapted to rupture in a magnetic field, comprising:
a microcapsule having 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 the microcapsule, wherein the microcapsule is to be added into a thermal interface material (TIM) gap filler, and 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 microcapsule in a magnetic field.

8. The microcapsule adapted to rupture in a magnetic field as recited in claim 7 , wherein the microcapsule is a urea-formaldehyde (UF) microcapsule having a shell into which one or more (3-aminopropyl) trimethylsilane-coated magnetite nanoparticles is/are covalently bound.

9. The microcapsule adapted to rupture in a magnetic field as recited in claim 8 , wherein the shell of the UF microcapsule encapsulates toluene.

Assignees

• IBM

Inventors

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

Classifications

• B32B43/006

  Delaminating · CPC title

• B32B2307/208

  Magnetic, paramagnetic · CPC title

• Y10T156/1111

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

• B32B2457/00

  Electrical equipment · CPC title

• C09K5/08

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