US-12625331-B2 - Thermal interface material assemblies

US12625331B2US 12625331 B2US12625331 B2US 12625331B2US-12625331-B2

Abstract

Exemplary embodiments are disclosed of thermal interface solutions for sliding surfaces. In an exemplary embodiment, a thermal interface material assembly includes a substrate having opposite first and second surfaces. An antifriction layer is along the first surface of the substrate. A thermal interface material is along the second surface of the substrate, such that the substrate is between the antifriction layer and the thermal interface material. The antifriction layer is configured to slide along in contact with a first surface of a first component when the thermal interface material assembly is along a second surface of a second component and when the first and second surfaces are slidably moved relative to each other.

Inventors

Ping Wang
Qiuju Wu
Jianshan LIAO
Jingqi Zhao
Weiqing Guo

Assignees

LAIRD TECHNOLOGIES (SHENZHEN) LTD.

Dates

Publication Date: 20260512
Application Date: 20230323
Priority Date: 20220401

Claims (20)

1 . A thermal interface material assembly comprising: a substrate having opposite first and second surfaces; an antifriction layer along the first surface of the substrate; and a thermal interface material along the second surface of the substrate, such that the substrate is between the antifriction layer and the thermal interface material; wherein the antifriction layer is configured to have a lower coefficient of friction than the substrate; wherein the thermal interface material has a higher thermal conductivity than each of the substrate and the antifriction layer; wherein the antifriction layer comprises polytetrafluoroethylene, molybdenum disulfide, graphite, polyethylene, polypropylene, aluminum oxide, boron nitride, calcium fluoride, tungsten carbide, and/or aluminum; wherein the substrate comprises a polyimide film having a thermal conductivity within a range from 0.1 to 2 Watts per meter per Kelvin and a thickness within a range from 3 microns to 50 microns; wherein a pressure sensitive adhesive (PSA) structure is disposed along edge portions of the thermal interface material, the PSA structure including first and second PSA strips along opposed edges parallel to a direction of sliding, the PSA structure adhesively attaches the TIM assembly to a second surface of a second component and defines a channel that laterally confines the thermal interface material between the opposed edges, wherein the substrate overlies and spans the channel and the first and second PSA strips to define a wear-resisting layer over the thermal interface material; whereby the antifriction layer is configured to slide along in contact with a first surface of a first component when the thermal interface material assembly is along the second surface of the second component such that the substrate and the antifriction layer along the first surface of the substrate intervenes between the first surface of the first component and the thermal interface material along the second surface of the substrate thereby preventing direct contact between the thermal interface material and the first surface of the first component when the first surface of the first component and the second surface of the second component are slidably moved relative to each other.
2 . The thermal interface material assembly of claim 1 , wherein the thermal interface material comprises a thermal phase change material.
3 . The thermal interface material assembly of claim 1 , wherein the antifriction layer is configured to have a coefficient of friction less than 0.25.
4 . The thermal interface material assembly of claim 1 , wherein the antifriction layer comprises polytetrafluoroethylene (PTFE) and/or molybdenum disulfide as a dry-lubricant coating having a thickness within a range from 1 micron to 30 microns and a coefficient of friction less than 0.25.
5 . The thermal interface material assembly of claim 1 , wherein the antifriction layer comprises a dry lubricant applied along the first surface of the substrate and configured to slide along in contact with the first surface of the first component without leaving visible residue from the dry lubricant along the first surface of the first component after at least 500 sliding insertion/removal cycles at a temperature of 75° C. or above.
6 . The thermal interface material assembly of claim 1 , wherein the antifriction layer comprises molybdenum disulfide.
7 . The thermal interface material assembly of claim 1 , wherein the antifriction layer comprises polytetrafluoroethylene.
8 . The thermal interface material assembly of claim 1 , wherein: the antifriction layer comprises polytetrafluoroethylene and/or molybdenum disulfide; and the antifriction layer is configured to have a coefficient of friction less than 0.25.
9 . The thermal interface material assembly of claim 1 , wherein, when installed between a pluggable transceiver cage/housing and a connector plug received therein, the thermal interface material assembly provides a temperature reduction of at least 5° C. at 20 W relative to a configuration without the assembly and withstands at least 500 insertion/removal cycles without detachment or material transfer.
10 . The thermal interface material assembly of claim 1 , wherein; the antifriction layer comprises polytetrafluoroethylene (PTFE) and/or molybdenum disulfide as a dry-lubricant coating having a thickness within a range from 1 micron to 30 microns and a coefficient of friction less than 0.25; the antifriction layer is configured not to transfer visible residue to the first component after at least 500 sliding insertion/removal cycles at a temperature of 75° C. or above; and when installed between a pluggable transceiver cage/housing and a connector plug received therein, the thermal interface material assembly provides a temperature reduction of at least 5° C. at 20 W relative to a configuration without the assembly and withstands at least 500 insertion/removal cycles without detachment or material transfer.
11 . The thermal interface material assembly of claim 1 , wherein: the antifriction layer comprises an antifriction coating along the first surface of the substrate, the antifriction coating comprising polytetrafluoroethylene and/or molybdenum disulfide, the antifriction layer having a coefficient of friction less than 0.25 and less than a coefficient of friction of the dielectric polyimide film; and the thermal interface material comprises a thermal phase change material having a thermal conductivity of at least 3 Watts per meter per Kelvin.
12 . The thermal interface material assembly of claim 1 , wherein the thermal interface material comprises a thermal phase change material having a thermal conductivity of at least 3 Watts per meter per Kelvin.
13 . The thermal interface material assembly of claim 1 , wherein the substrate comprises a non-metallized polyimide film with surface roughness Ra 0.02-0.07 microns, thermal interface material assembly is adhesively attached to the second surface of the second component.
14 . The thermal interface material assembly of claim 1 , wherein the first and second PSA strips are continuous and gap-free along the opposed edges parallel to the direction of sliding.
15 . The thermal interface material assembly of claim 1 , wherein the PSA structure further comprises additional PSA segments along edges perpendicular to the sliding direction, such that the PSA defines a perimeter frame bounding the thermal interface material.
16 . The thermal interface material assembly of claim 1 , wherein the pressure sensitive adhesive comprises first and second layers of pressure sensitive adhesive along opposite first and second sides of a polyethylene terephthalate film.
17 . The thermal interface material assembly of claim 1 , wherein: the thermal interface material includes edge portions defining an outer perimeter; and the pressure sensitive adhesive is disposed along the edge portions of the thermal interface material around the outer perimeter of the thermal interface material, such that the pressure sensitive adhesive is between and adhesively attaches the second surface of the substrate to the second surface of the second component.
18 . The thermal interface material of claim 17 , wherein the pressure sensitive adhesive provides reinforcement along the edge portions of the thermal interface material that are parallel and/or perpendicular to a direction in which the second surface of the second component is slidable relative to the first surface of the first component when the thermal interface material assembly is between the first and second surfaces of the respective first and second components.
19 . The assembly of claim 17 , wherein the pressure sensitive adhesive provides reinforcement along the edge portions of the thermal interface material that helps to confine the thermal interface material within an area defined by the reinforcement and thereby inhibits migration of the thermal interface material.
20 . The thermal interface material assembly of claim 1 , wherein a central region between the first and second PSA is substantially free of PSA, thereby reducing migration of the thermal interface material during thermal cycling.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to and the benefit of Chinese Invention Patent Application No. 202210338316.6 filed Apr. 1, 2022. The disclosure of this application identified in this paragraph is incorporated herein by reference in its entirety. FIELD The present disclosure generally relates to thermal interface solutions for sliding surfaces. BACKGROUND This section provides background information related to the present disclosure which is not necessarily prior art. Electrical components, such as semiconductors, integrated circuit packages, transistors, etc., typically have pre-designed temperatures at which the electrical components optimally operate. Ideally, the pre-designed temperatures approximate the temperature of the surrounding air. But the operation of electrical components generates heat. If the heat is not removed, the electrical components may then operate at temperatures significantly higher than their normal or desirable operating temperature. Such excessive temperatures may adversely affect the operating characteristics of the electrical components and the operation of the associated device. To avoid or at least reduce the adverse operating characteristics from the heat generation, the heat should be removed, for example, by conducting the heat from the operating electrical component to a heatsink. The heatsink may then be cooled by conventional convection and/or radiation techniques. During conduction, the heat may pass from the operating electrical component to the heatsink either by direct surface contact between the electrical component and heatsink and/or by contact of the electrical component and heatsink surfaces through an intermediate medium or thermal interface material (TIM). The thermal interface material may be used to fill the gap between thermal transfer surfaces, in order to increase thermal transfer efficiency as compared to having the gap filled with air, which is a relatively poor thermal conductor. SUMMARY This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features. Exemplary embodiments are disclosed of thermal interface solutions for sliding surfaces. In an exemplary embodiment, a thermal interface material assembly includes a substrate having opposite first and second surfaces. An antifriction layer is along the first surface of the substrate. A thermal interface material is along the second surface of the substrate, such that the substrate is between the antifriction layer and the thermal interface material. The antifriction layer is configured to slide along in contact with a first surface of a first component when the thermal interface material assembly is along a second surface of a second component and when the first and second surfaces are slidably moved relative to each other. Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. DRAWINGS The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations and are not intended to limit the scope of the present disclosure. FIG. 1 is a cross-sectional view of a substrate (e.g., polyimide (PI) or other polymer substrate, a metal substrate, etc.) including an antifriction coating (e.g., polytetrafluoroethylene (PTFE) and/or molybdenum disulfide (MoS2) based anti-friction coating, etc.) along a first side of the substrate according to an exemplary embodiment of a thermal solution or thermal interface material assembly. FIG. 2 is a cross-sectional view of a thermal solution or thermal interface material assembly according to an exemplary embodiment in which a thermal interface material (TIM) (e.g., thermal phase change material (PCM), etc.) and pressure sensitive adhesive (PSA) are along an opposite second side of the substrate shown in FIG. 1. FIG. 3 illustrates an exemplary embodiment of a thermal interface material assembly applied to a pedestal or platform of an example heatsink. FIGS. 4, 5, and 6 illustrate an example of a heatsink including a pedestal or platform on which may be applied the thermal interface material assembly shown in FIG. 2. FIG. 7 illustrates the heatsink shown in FIGS. 4, 5, and 6 positioned along a top of a cage of a small form-factor pluggable (SFP) fiber optic transceiver. FIG. 8 illustrates the heatsink and SFP cage shown in FIG. 7, and further illustrating a connector plug within a cavity defined by the cage of the SFP transceiver. FIG. 9 illustrates the heatsink shown in FIGS. 4, 5, and 6, and also illustrating first and second strips of adhesive material (e.g., pressure sensitive adhesive, etc.) along opposing first and second edge portions of the heatsink pedestal. A thermal interface material (e.g., thermal pha