Thermal interface materials with reinforcement for abrasion resistance and/or suitable for use between sliding components

Exemplary embodiments are disclosed of thermal interface materials with reinforcement for abrasion resistance and/or suitable for use between sliding components.

FIELD

The present disclosure generally relates to thermal interface materials with reinforcement for abrasion resistance and/or suitable for use between sliding components.

BACKGROUND

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 heat sink. The heat sink may then be cooled by conventional convection and/or radiation techniques. During conduction, the heat may pass from the operating electrical component to the heat sink either by direct surface contact between the electrical component and heat sink and/or by contact of the electrical component and heat sink 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.

DETAILED DESCRIPTION

The inventors hereof have recognized that some conventional thermal interface materials may not be sufficiently durable to withstand or resist the abrasion that may occur when a thermal interface material is used between sliding components. Accordingly, exemplary embodiments are disclosed herein of thermal interface materials with reinforcement for resisting abrasion when used between sliding components.

As disclosed herein, a thermal interface material (TIM) may be reinforced for resisting abrasion from kinetic or sliding friction when the TIM is relatively slid against a surface of another component. For example, the TIM may be slid along the surface of the another component while the another component is stationary. Or, for example, the TIM may be stationary while the another component slides along the TIM. As yet another example, both the TIM and the another component may slide relatively along each other, e.g., in opposite directions and/or in a same direction but at different speeds, etc.

In exemplary embodiments, a TIM is disposed (e.g., attached, applied, etc.) along a surface of a first component. For example, the TIM may be manually applied, stenciled, screen printed, applied using pick-n-place equipment, applied (e.g., tamped and removed, etc.) from a supply reel or roll, etc. The TIM may be relatively slid against a surface of a second component. The first and second components may comprise a wide range of components, such as a heat sink, a heat spreader, a heat pipe, a vapor chamber, other heat removal/dissipation structure, a portion of a housing or cage, a surface within a cavity, etc. For example, the TIM may be disposed along a surface of a first component that is slid into and/or out of a cavity. Or, for example, the TIM may be disposed along a surface within a cavity, and another component may be slid into and/or out of the cavity in which the TIM is disposed. In these examples, the TIM may be disposed along a first component that may comprise a connector plug, a slidable part of a tablet or other modular portable device, etc. The cavity may be defined by a cage of a transceiver (e.g., small form-factor pluggable (SFP) fiber optic transceiver, etc.), by a tablet, by a modular portable device in which parts are slid into place instead of layered on top of each other, etc.

In an exemplary embodiment, a TIM with reinforcement is disposed along a heat removal/dissipation structure (e.g., heat sink, heat pipe, vapor chamber, heat spreader, another TIM, etc.). The heat removal/dissipation structure is disposed within or is an integral part of a cage (broadly, a housing) of a transceiver (broadly, a device), such as a small form-factor pluggable (SFP) transceiver, SFP+ transceiver, quad small form-factor pluggable (QSFP) transceiver, QSFP+ transceiver, XFP transceiver, etc. As disclosed herein, the TIM may be reinforced to resist abrasion during connector plug insertion into and/or removal from a cage or housing.

Although exemplary embodiments of TIMs with reinforcement may be used with transceivers, the TIMs with reinforcement may be used with a wide range of other devices, including wide range of transceivers, other devices having housings, cages, or cavities, other devices configured for use with other connectors besides SFP cable connectors, modular portable devices (e.g., tablets, etc.) in which parts are slid into place instead of being layered or stacked on top of each other, etc. For example, another exemplary embodiment includes a TIM with reinforcement disposed along a part or subcomponent of a tablet or modular portable device.

In exemplary embodiments, the thermal interface materials (TIMs) have low effective thermal resistance (e.g., less than 2° C./W, less than 0.2° C./W, within a range from about 0.2° C./W to about 2° C./W, etc.). As disclosed herein, reinforcements are provided such that the TIMs have sufficiently good durability and abrasion resistance. Advantageously, the reinforcement may allow the TIM to survive and/or withstand sliding operations (e.g., repeated connector plug insertion into and/or removal from a cage of a transceiver, sliding installation of a component, etc.) including at elevated temperatures (e.g., 75° C. or above, etc.). The reinforcement may be configured to confine the TIM within a predetermined area (e.g., a channel along a heat sink, other heat removal/dissipation structure, etc.) such that the TIM is contained within the predetermined area (e.g., the TIM is not abraded or scraped, etc.) during sliding operations (e.g., during connector plug insertion/removal process, component or part sliding installation, etc.) thereby maintaining TIM integrity.

In exemplary embodiments, a thermal interface material (TIM) is disposed along (e.g., attached or coupled in thermal contact with, etc.) a first component, e.g., a heat sink, heat pipe, vapor chamber, heat spreader, other heat removal/dissipation structure, other component, etc. For example, the TIM may be positioned along a first surface of a first component that is opposite a second surface of the first component, which second surface is coupled to an inner surface within and/or defining part of a cavity. The first component may thus be generally between (e.g., attached or coupled in thermal contact with, etc.) the TIM and the inner surface of the cavity. The TIM may be generally between the first component and a second component when the second component is slidably positioned within the cavity.

The TIM and the first component may cooperatively define or establish a thermally-conductive heat path from the second component to the inner surface of the cavity. Therefore, heat may be transferred along this thermally-conductive heat path from the second component to the TIM, from the TIM to the first component, and from the first component to the inner surface of the cavity. From the inner surface of the cavity, heat may be transferred through the cavity wall to an external component outside the cavity, such as a heat sink, other heat removal/dissipation structure (e.g., heat spreader, etc.), and/or to the environment.

In other exemplary embodiments, the first component may be the component (or portion thereof) that integrally defines the cavity. In yet other exemplary embodiments, the first component may be eliminated, and the TIM may be disposed directly along the inner surface of the cavity without any intervening components between the TIM and the inner surface of the cavity. Additionally, or alternatively, a TIM may be disposed along (e.g., attached or coupled in thermal contact with, etc.) the second component. In this example, the TIM may be slid into and out of the cavity along with the second component when the second component is slidably inserted into and removed from the cavity.

To improve survivability of the TIM during the relatively sliding of the first and second components (e.g., repeated connector plug insertion into and/or removal from an SFP cage, sliding installation of the first component, etc.), exemplary embodiments disclosed herein include reinforcements along one or more edge or perimeter portions of the TIMs. For example, reinforcement may be provided at least partially along the TIM's opposing edge or perimeter portions that are generally perpendicular to and/or parallel with the directions in which the second component is slidably inserted into/removed from the cavity. Or, for example, reinforcement may be provided along the TIM's entire perimeter or along all of the TIM's edges such that the reinforcement generally surrounds the TIM.

In an exemplary embodiment, strips of reinforcement material (e.g., polyethylene terephthalate (PET) or polyimide film, etc.) are applied along a portion of a first component. For example, first and second strips of reinforcement material may be applied along opposing first and second longitudinal edges of a pedestal or platform (broadly, a protruding portion) of a heat sink or other heat removal/dissipation structure, etc. Thermal interface material (TIM) is applied or added within the channel or area defined generally between the strips of reinforcement material. As compared to the strips of reinforcement material, the TIM is softer, more compliant, less durable, and/or more susceptible to abrasion (e.g., more susceptible to scraping or abrading away from kinetic or sliding friction when the TIM is relatively slid against a surface of a second component, etc.). During the sliding motion of a second component relative to the first component, the strips of reinforcement material may absorb compression forces and help confine the TIM within the channel or area defined generally between the strips of reinforcement material, thereby helping to maintain integrity of the softer TIM.

In another exemplary embodiment, reinforcement of a first TIM is provided by one or more wall portions of a second TIM (broadly, a second material) disposed at least partially around the first TIM. As compared to the second TIM, the first TIM is softer, more compliant, less durable, and/or more susceptible to abrasion (e.g., scraping or abrading away, etc.). The wall portions of the second TIM are configured to confine the first TIM within a predetermined area defined generally between the wall portions. For example, the wall portions of the second TIM may provide or define a channel, pocket, or walled off area along a surface of a first component in which the first TIM is contained even when the first TIM is contacted by a second component sliding relative to the first component. During the sliding motion of the second component relative to the first component, the wall portions of the second TIM absorb compression forces thereby helping to maintain integrity of the softer first TIM.

The wall portions of the second TIM may completely surround an entire perimeter of the first TIM to inhibit or prevent migration of the first TIM in all directions along the heat sink. Or, for example, the wall portions of the second TIM may be along only the first TIM's opposing edge or perimeter portions that are generally parallel with or perpendicular to first and second directions in which the second component is slid relative to the first component, thereby inhibiting or preventing migration of the first TIM along the heat sink in the first and second directions. Further, the one or more wall portions along the edges of the first TIM may be formed from the same material(s), or at least one wall portion may be made from a material(s) different than the material(s) used to make another one of the wall portions.

The first and/or second TIM may comprise a wide range of other thermal interface materials. In addition, other exemplary embodiments may include another material(s) (e.g., non-thermally enhanced material, thermal insulator, etc.) besides a thermal interface material that are used to provide one or more wall portions to reinforce and confine the first TIM.

The wall portions of the second TIM may have a height greater than or about equal to a thickness of the first TIM, such that only a relatively thin portion (or none at all) of the first TIM protrudes beyond the wall portions of the second TIM. The first TIM may have a coefficient of thermal expansion (CTE) (e.g., a known CTE higher than the CTE of the second TIM, etc.) such that upon heating the first TIM may expand and increase contact with the first component and second component resulting in a lower thermal resistance. The first TIM may be an exposed grease that comes in direct contact with the first and second components, or the first TIM may be a material contained inside of another more robust material that allows for abrasion resistance, such as during a “hot swap” at 75° C., etc.

Another exemplary embodiment includes building up a dam (or one or more wall portions) along the surface of a first component with a material harder than the TIM, such as polyethylene terephthalate (PET) or polyimide film, etc. The dam of the harder material defines or provides a channel, pocket, or walled off area along the first component to which the softer TIM is added. The dam of the harder material may generally surround the softer TIM to thereby reinforce the softer TIM and confine the softer TIM to the predetermined area defined by the dam along the first component. During the sliding of the second component relatively along the first component, the dam of the harder material may absorb compression forces thereby helping to maintain integrity of the softer TIM.

The dam of harder material may have a height greater than or about equal to a thickness of the softer TIM, such that only a relatively thin portion (or none at all) of the softer TIM protrudes beyond the dam. The softer TIM may have a coefficient of thermal expansion (CTE) (e.g., a known CTE higher than the CTE of the harder material used for the dam, etc.) such that upon heating the softer TIM may expand and increase contact with the first and second components resulting in a lower thermal resistance. The softer TIM may be an exposed grease that comes in direct contact with the first and second components.

In another exemplary embodiment, a channel, pocket, recess, or other predetermined area is formed directly on the surface of a first component, such as by machining (e.g., milling, etc.), etching, other material removal process, etc. Or, for example, the first component may instead be initially formed (e.g., die cast, molded, etc.) to integrally include the channel, pocket, recess, etc. By way of example, the surface of the first component may be milled to create a recess, pocket, channel, etc. to which a TIM (e.g., thermal grease, thermal phase change material, other soft or compliant TIM, etc.) is added.

The depth of the milled recess, pocket, channel, etc. along the first component is preferably sufficient such that the TIM is entirely or mostly confined within the milled recess, pocket, channel, etc. such that only a relatively thin portion (or none at all) of the TIM protrudes beyond the surface of the first component. The TIM may have a coefficient of thermal expansion (CTE) (e.g., a known CTE higher than the CTE of the heat sink, etc.) such that upon heating the TIM may expand and increase contact with the first and second components resulting in a lower thermal resistance. The TIM may be an exposed grease that comes in direct contact with the first and second components.

With reference now to the figures,FIGS. 1, 2, and 3illustrate an example of a heat sink104(broadly, heat removal/dissipation structure) including a pedestal or platform108(broadly, a portion). The pedestal108protrudes outwardly from a surface of a first side112of the heat sink104. A plurality of fins116protrude outwardly from a second side120of the heat sink104opposite the first side112.

As shown inFIG. 4, first and second strips of reinforcement material124,128(broadly, reinforcement) are applied along (e.g., entirely and continuously along without any gaps, etc.) opposing first and second edges132,136of the heat sink pedestal108according to this exemplary embodiment. By way of example, the first and second strips of reinforcement material124,128may comprise polyethylene terephthalate (PET) or polyimide film. Alternatively, other reinforcement materials may be used for the strips124,128that are harder, less compliant, more durable, and/or less susceptible to abrasion than the thermal interface material (TIM)140shown inFIG. 5. In addition, other exemplary embodiments may include strips of reinforcement material along less than the entire length of the pedestal edges and/or in a non-continuous pattern (e.g., spaced apart strip portions with gaps therebetween, etc.) along the pedestal edges, and/or along other edges of the pedestal, etc. For example, another exemplary embodiment may include four strips of reinforcement material along each of the four edges of the rectangular pedestal. Also, other exemplary embodiments may include a heat sink with a non-rectangular pedestal and/or strips of reinforcement materials that are not all made of the same material.

The TIM140(FIG. 5) is applied along the heat sink pedestal108within a channel110(FIG. 4) (broadly, an area) defined generally between the first and second strips of reinforcement material124,128. As disclosed herein, a wide range of thermal interface materials may be used for the TIM140, such as a thermal gap filler, thermal phase change material, thermally-conductive EMI absorber or hybrid thermal/EMI absorber, thermal putty, thermal pad, thermal grease, etc. In exemplary embodiments, the TIM140has a higher thermal conductivity than the strips of reinforcement material124,128. But the TIM140is softer, more compliant, less durable, and/or more susceptible to abrasion than the strips of reinforcement material124,128. When another component (e.g., SFP connector plug, SFP cage, etc.) is slid relative to the heat sink104and TIM140, the strips of reinforcement material124,128may absorb compression forces and help confine the TIM140within the channel or area110defined generally between the strips of reinforcement material124,128, thereby helping to maintain integrity of the TIM140.

The thickness of the TIM140may be sufficient such that the TIM140does not protrude beyond the thickness or height of the strips of reinforcement material124,128. Stated differently, the strips of reinforcement material124,128may have a thickness or height greater than or about equal to a thickness of the TIM140, such that only a relatively thin portion (or none at all) of the TIM140protrudes beyond the strips of reinforcement material124,128.

The TIM140may have a coefficient of thermal expansion (CTE) (e.g., a known CTE higher than the CTE of the strips of reinforcement material124,128, etc.) such that upon heating the TIM140expands and increases contact with the heat sink104and the second component (e.g., SFP connector plug, etc.) resulting in a lower thermal resistance.

The assembly100(FIG. 5) including the heat sink104, strips of reinforcement materials124,128, and TIM140may be used with a wide range of devices. Also, aspects of the present disclosure are not limited to use with only heat sinks as the strips of reinforcement materials124,128and TIM140may be applied to other heat removal/dissipation structures and/or components, e.g., a heat removal/dissipation structure that is part of a housing or cage itself, a heat pipe, a vapor chamber, a heat spreader, etc.

For purposes of example only,FIGS. 6 and 7illustrate an exemplary embodiment in which the assembly100(FIG. 5) is used with a small form-factor pluggable (SFP) fiber optic transceiver144(broadly, a device or component). As shown inFIG. 6, the heat sink104is positioned along a top of an SFP cage148(broadly, a housing) with the pedestal108facing downwardly relative to the top of the SFP cage148. The heat sink104may be coupled to the SFP cage148by one or more spring clips, screws, other mechanical fasteners, etc.

As shown inFIG. 7, the TIM140along the pedestal108thermally contacts a portion152of an SFP connector plug156(broadly, a connector) when the portion152of the SFP connector plug152is slidably inserted into the cavity162defined by or within the SFP cage148. In this example, the strips of reinforcement material124,128may absorb compression forces and help confine the TIM140within the channel or area110defined generally between the strips of reinforcement material124,128when the portion152of the SFP connector plug152is slidably inserted into or removed from the cavity162, thereby helping to maintain integrity of the TIM140.

The TIM140may be generally between the heat sink104and the connector plug156when the connector plug156is within the cage148. Accordingly, the TIM140and the heat sink104may cooperatively define or establish at least a portion of a thermally-conductive heat path from the connector plug156to the fins116of the heat sink104. Therefore, heat may be transferred along this thermally-conductive heat path from the connector plug156to the TIM140, from the TIM140to the heat sink104, and from the heat sink fins116to another heat removal/dissipation structure (e.g., heat spreader, etc.), and/or to the environment. The heat transfer may reduce a temperature of the cage148and the cable connector156, to thereby help maintain a temperature of the cage148and the cable connector156below a specified threshold, etc. The TIM140and the heat sink104may include any suitable materials, configurations, etc. suitable to reduce the temperature of the cage148and cable connector156. For example, the TIM and heat sink materials and configurations may be selected such that the TIM140and the heat sink104are capable of dissipating heat at a rate sufficient to maintain the temperature of the cage148and the cable connector156below a specified threshold temperature at which operation of the cable connector156would otherwise be impaired. Transfer of heat to the TIM140may reduce the amount of heat that is transferred from the cable connector156to another component, such as a printed circuit board (PCB) of the SFP transceiver144, thereby reducing the amount of heat that could dissipate further from the PCB to more heat sensitive components.

By way of background, small form-factor pluggable (SFP) fiber optic transceivers are compact, hot-pluggable transceivers that may be used for telecommunications, data communications applications, etc. A SFP transceiver may interface a network device motherboard (e.g., for a switch, router, media converter, etc.) to a fiber optic or copper networking cable. SFP transceivers may support communications standards including SONET, gigabit Ethernet, Fibre Channel, etc. As used herein, small form-factor pluggable (SFP) may also include or be used in reference to other small form-factor pluggables, such as SFP+, quad (4-channel) small form-factor pluggable (QSFP), QSFP+, etc.

A conventional SFP transceiver assembly may include a pluggable module or connector plug and a receptacle assembly, which, in turn, is mounted on a printed circuit board (PCB). The pluggable module may be configured to be inserted into a front opening and cavity defined by a cage of the receptacle assembly. The pluggable module may include a housing having a portion that is held against a heat sink (e.g., at a moderate pressure, etc.) after the pluggable module is inserted into the cage. The pluggable module may subsequently be removed from the cage of the receptacle assembly. A connector plug or pluggable module may undergo numerous insertions into and removals from a cage (e.g., QSFP cage, etc.). And, the insertion/removal process may occur at elevated temperatures, such as when the junction temperature is 75 degrees Celsius (° C.) or above, etc.

But the inventors hereof have recognized that conventional thermal solutions for SFP transceivers either lack low thermal resistance and/or are not durable to withstand repeated insertion/removal of a connector plug. Accordingly, the inventors have developed and/or disclose herein exemplary embodiments of thermal interface materials (TIMs) (e.g., TIM140, etc.) with low effective thermal resistance (e.g., less than 2° C./W, less than 0.2° C./W, within a range from about 0.2° C./W to about 2° C./W, etc.) and with reinforcement (e.g., strips of reinforcement materials124,128, etc.) for good durability and abrasion resistance, such that the TIMs are useful between sliding components, such as between an connector (e.g., connector plug156, etc.) and a housing or cage (e.g., SFP cage148, etc.), etc. Advantageously, the reinforcement may allow the TIM to survive and/or withstand repeated connector plug insertion into and/or removal from a cage of a transceiver or other device including at elevated temperatures (e.g., 75° C. or above, etc.). The reinforcement may be configured to confine the TIM within a predetermined area (e.g., along a heat sink, along another heat removal/dissipation structure, along a portion of the SFP cage itself, etc.) such that the TIM is contained within the predetermined area (e.g., the TIM is not abraded or scraped away, etc.) during the connector plug insertion/removal process, thereby maintaining TIM integrity. The reinforcement may improve survivability of the TIM during repeated connector plug insertion into and/or removal from an SFP cage.

The cage (e.g., cage148, etc.) may be any suitable cage capable of receiving an SFP cable connector. The cage may have dimensions corresponding to an SFP connector to allow insertion of the SFP cable connector plug into the cage. The cage may receive the cable connector plug via any suitable releasably coupled engagement, including but not limited to a friction fit, a snap fit, etc. The cage may include an interface for transmitting and/or receiving signals via the SFP connector, such as an optical cable interface, an electrical cable interface, etc. The interface may allow for communication to and/or from the cable connector to a motherboard, printed circuit board (PCB), network card, etc. to which the cage is mounted.

The cage (e.g., cage148, etc.) may comprise any suitable material, including metal, etc. For example, the cage may comprise a material suitable for shielding against noise generated by the transfer of data through the cable connector plug (e.g., electromagnetic interference (EMI) shielding, etc.). Alternative embodiments may include other devices, such as other transceivers (e.g., SFP+ transceivers, XFP transceivers, QSFP transceivers, QSFP+ transceiver, etc.), devices having housings or cages configured for use with other connectors besides SFP cable connectors, etc. Accordingly, aspects of the present disclosure should not be limited to SFP transceivers and SFP cable connectors.

Some exemplary embodiments may include one or more thermoelectric module, such as a thermoelectric module coupled between a side of the cage and the heat sink and/or a thermoelectric module coupled between the TIM and the heat sink, etc. A thermoelectric module may be any suitable module capable of transferring heat between opposing sides of the module when a voltage is applied to the module. A thermoelectric module may have a hot side oriented towards the connector plug within the cage and a cold side oriented in a direction away from the connector plug within the cage.

Example thermal interface materials that may be used in exemplary embodiments include thermal gap fillers, thermal phase change materials, thermally-conductive EMI absorbers or hybrid thermal/EMI absorbers, thermal putties, thermal pads, etc.

In some embodiments, the TIM may include a silicone elastomer. The silicone elastomer may be filled with a suitable thermally-conductive material, including ceramic, boron nitride, etc. In some embodiments, the TIM may comprise a graphite sheet material, a metal foil, a multi-laminate structure, such as a multi-laminate structure of metal and plastic, a multi-laminate structure of metal and graphite, or a multi-laminate structure of metal, graphite, and plastic.

In some exemplary embodiments, the TIM may comprise a compliant gap filler having high thermal conductivity. By way of example, the TIM may comprise a thermal interface material of Laird, such as one or more of Tflex™ 200, Tflex™ HR200, Tflex™ 300, Tflex™ 300 TG, Tflex™ HR400, Tflex™ 500, Tflex™ 600, Tflex™ HR600, Tflex™ SF600, Tflex™ 700, Tflex™ SF800 thermal gap fillers.

The TIM may comprise an elastomer and/or ceramic particles, metal particles, ferrite EMI/RFI absorbing particles, metal or fiberglass meshes in a base of rubber, gel, or wax, etc. The TIM may include compliant or conformable silicone pads, non-silicone based materials (e.g., non-silicone based gap filler materials, thermoplastic and/or thermoset polymeric, elastomeric materials, etc.), silk screened materials, polyurethane foams or gels, thermally-conductive additives, etc. The TIM may be configured to have sufficient conformability, compliability, and/or softness (e.g., without having to undergo a phase change or reflow, etc.) to adjust for tolerance or gaps by deflecting at low temperatures (e.g., room temperature of 20° C. to 25° C., etc.) and/or to allow the thermal interface materials to closely conform (e.g., in a relatively close fitting and encapsulating manner, etc.) to a mating surface when placed in contact with (e.g., compressed against, etc.) the mating surface, including a non-flat, curved, or uneven mating surface.

The TIM may include a soft thermal interface material formed from elastomer and at least one thermally-conductive metal, boron nitride, and/or ceramic filler, such that the soft thermal interface material is conformable even without undergoing a phase change or reflow. In some exemplary embodiments, the TIM may include ceramic filled silicone elastomer, boron nitride filled silicone elastomer, or a thermal phase change material that includes a generally non-reinforced film.

Exemplary embodiments may include one or more thermal interface materials having a high thermal conductivity (e.g., 1 W/mK (watts per meter per Kelvin), 1.1 W/mK, 1.2 W/mK, 2.8 W/mK, 3 W/mK, 3.1 W/mK, 3.8 W/mK, 4 W/mK, 4.7 W/mK, 5 W/mK, 5.4 W/mK, 6 W/mK, etc.) depending on the particular materials used to make the thermal interface material and loading percentage of the thermally conductive filler, if any. These thermal conductivities are only examples as other embodiments may include a thermal interface material with a thermal conductivity higher than 6 W/mK, less than 1 W/mK, or other values and ranges between 1 and 6 W/mK. Accordingly, aspects of the present disclosure should not be limited to use with any particular thermal interface material as exemplary embodiments may include a wide range of thermal interface materials.

In exemplary embodiments, the TIM may comprise one or more graphite sheets such as one or more Tgon™ 9000 series graphite sheets. Tgon™ 9000 series graphite sheets comprise synthetic graphite thermal interface materials having a carbon in-plane mono-crystal structure and that are ultra-thin, light-weight, flexible and offer excellent in-plane thermal conductivity. Tgon™ 9000 series graphite sheets are useful for a variety of heat spreading applications where in-plane thermal conductivity dominates and in limited spaces. Tgon™ 9000 series graphite sheets may have a thermal conductivity from about 500 to about 1900 W/mK, may help reduce hot spots and protect sensitive areas, may enable slim device designs due to the ultra-thin sheet thickness of about 17 micrometers to 25 micrometers, may be bight weight with density from about 2.05 g/cm3to 2.25 g/cm3, may be flexible and able to withstand more than 10,000 times bending with radius of 5 millimeters. Table 1 below includes addition details about Tgon™ 9000 series graphite sheets.

The term “about” when applied to values indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring or using such parameters. For example, the terms “generally”, “about”, and “substantially” may be used herein to mean within manufacturing tolerances.