Selectively cross-linked thermal interface materials

Patent metadata

Field	Value
Publication number	US-10903188-B2
Application number	US-201916459958-A
Country	US
Kind code	B2
Filing date	Jul 2, 2019
Priority date	Mar 22, 2017
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

A process of forming a thermal interface material structure includes selectively masking a putty pad that includes ultraviolet (UV) curable cross-linkers to form a masked putty pad. The masked putty pad has a first area that is exposed and a second area that is masked. The process also includes exposing the masked putty pad to UV light to form a selectively cross-linked putty pad. The process includes disposing the selectively cross-linked putty pad between an electrical component and a heat spreader to form an assembly. The process further includes compressing the assembly to form a thermal interface material structure that includes a selectively cross-linked thermal interface material.

First claim

What is claimed is:

1. A process of forming a selectively cross-linked putty pad, the process comprising:
selectively masking a putty pad that includes ultraviolet (UV) curable cross-linkers to form a masked putty pad, the masked putty pad having a first area that is exposed and a second area that is masked; and
forming a selectively cross-linked putty pad by exposing the masked putty pad to UV light, the selectively cross-linked putty pad having the UV curable cross-linkers in a cross-linked state in the first area and in a non-crosslinked state in the second area.

2. The process of claim 1 , wherein the UV curable cross-linkers include compounds that reversibly cross-link via a reversible photodimerization reaction.

3. The process of claim 2 , wherein the UV curable cross-linkers include a coumarin compound, an anthracene compound, a cinnamic acid compound, a thymine compound, or a stilbene compound.

4. The process of claim 2 , wherein the putty pad includes a silicone material, and wherein the UV curable cross-linkers include a coumarin compound that is covalently bonded to the silicone material.

5. The process of claim 1 , further comprising:
disposing the selectively cross-linked putty pad between an electrical component and a heat spreader; and
compressing the electrical component and the heat spreader.

6. The process of claim 5 , wherein the putty pad includes a pre-cut pad having an appropriate shape for the electrical component.

7. The process of claim 5 , wherein the putty pad is formed from dispensable putty into an appropriate shape for the electrical component.

8. The process of claim 1 , wherein the first area is an area along edges of the putty pad.

9. The process of claim 1 , wherein the second area is an area in a central region of the putty pad.

10. The process of claim 1 , wherein the UV curable cross-linkers include epoxy, acrylate, vinyl, dimers, or other UV responsive moieties.

Assignees

• IBM

Inventors

• Campbell Eric J
• Czaplewski Sarah K
• Labreck Elin
• Porto Jennifer I

Classifications

• H10W90/736

  between a chip and a stacked lead frame, conducting package substrate or heat sink · CPC title

• H10W90/734

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title

• H10W72/07338

  hardening the adhesive by curing, e.g. thermosetting · CPC title

• H10W72/07332

  Compression bonding, e.g. thermocompression bonding · CPC title

• H10W72/07331

  Connecting techniques · CPC title