Gel-type thermal interface material

Abstract

The invention relates to a gel-type thermal interface material. The present disclosure provides a thermal interface material that can be used to transfer heat from heat-generating electronic devices, such as computer chips, to heat dissipation structures, such as heat sinks and fins. The thermal interface material comprises at least one silicone oil, at least one catalyst, at least one thermally conductive filler having a large surface area, a solvent, at least one inhibitor, and at least one crosslinking agent. The at least one thermally conductive filler reduces oil leakage of the TIM, and the solvent increases the flow rate of the TIM without counteracting the reduction of oil leakage achieved by the thermally conductive filler.

Description

[0001] This application is a divisional application of the invention patent application filed on February 13, 2019, with application number 201980019415.4 and entitled "Gel-type thermal interface material". Technical Field

[0002] This disclosure relates in general to thermal interface materials, and more specifically to gel-type thermal interface materials. Background Technology

[0003] Thermal interface materials (TIMs) are widely used to dissipate heat from electronic components such as central processing units, video graphics arrays, servers, game consoles, smartphones, and LED boards. TIMs are typically used to transfer excess heat from electronic components to heat sinks, such as heat exchangers.

[0004] Figure 1 A typical electronic package structure 10 incorporating thermal interface materials is illustrated. The electronic package structure 10 illustratively includes a heat-generating component (such as an electronic chip 12) and one or more heat-generating components (such as a heat sink 14 and a heatsink 16). The illustrative heat sink 14 and heatsink comprise metal, metal alloy, or metal-plated substrates, such as copper, copper alloy, aluminum, aluminum alloy, or nickel-plated copper. TIM materials (such as TIM 18 and TIM 20) provide thermal connections between the heat-generating component and one or more heat-generating components. The electronic package structure 10 includes a first TIM 18 connecting the electronic chip 12 and the heat sink 14. TIM 18 is generally referred to as "TIM1". The electronic package structure 10 includes a second TIM 20 connecting the heat sink 14 and the heatsink 16. TIM 20 is generally referred to as "TIM2". In another embodiment, the electronic package structure 10 does not include a heat sink 14, and a TIM (not shown) directly connects the electronic chip 12 to the heatsink 16. This type of TIM directly connecting the electronic chip 12 to the heatsink 16 is generally referred to as TIM1.5.

[0005] Traditional thermal interface materials include components such as spacers. However, spacers have certain drawbacks, such as being unable to meet very small thickness requirements and being difficult to use in automated production.

[0006] Other thermal interface materials include gel products. Gel products can be automatically dispensed for mass production and can be formed into desired shapes and thicknesses. However, typical gel products with good flow properties are potentially susceptible to oil leakage (also known as "exudation"). Improvements to these aspects are desired. Summary of the Invention

[0007] This disclosure provides a thermal interface material (TIM) for transferring heat from heat-generating electronic devices (such as computer chips) to heat-dissipating structures (such as heat sinks and fins). The TIM comprises at least one silicone oil, at least one catalyst, at least one thermally conductive filler having a relatively large surface area, a solvent, at least one inhibitor, and at least one crosslinking agent. The at least one thermally conductive filler reduces oil leakage of the TIM, and the solvent increases the flow rate of the TIM without offsetting the reduction in oil leakage achieved by the thermally conductive filler.

[0008] In one exemplary embodiment, a thermal interface material is provided. This thermal interface material comprises a weight-average molecular weight (Mi) of less than 50,000 Daltons. w Low molecular weight silicone oil; at least one having a molecular weight greater than 1.0 m 2 A thermally conductive filler with a surface area of ​​ / g; and a high molecular weight silicone oil, wherein the high molecular weight silicone oil comprises a weight-average molecular weight (Mn) of at least 60,000 Daltons. w Vinyl functional silicone oil.

[0009] In a more specific embodiment, the thermal interface material has a viscosity greater than 1500 Pa·s. In another more specific embodiment, the thermal interface material further comprises a solvent having a boiling point between 60°C and 220°C and a viscosity between 0.2 cSt and 50 cSt. In a more specific embodiment, the thermal interface material has a viscosity between 150 Pa·s and 650 Pa·s. In a more specific embodiment, at least one thermally conductive filler comprises a first thermally conductive filler, a second thermally conductive filler, and a third thermally conductive filler, wherein the first thermally conductive filler has a viscosity of 0.1 m... 2 / g to 1.0m 2 The second thermally conductive filler is a metal oxide with a surface area between 0.5 m² / g and 0.5 m² / g. 2 / g and 2.0m 2 The third thermally conductive filler has a surface area between 5.0 m² / g and 6.5 m² / g. 2 / g and 10.0m 2 Metal oxides with a surface area between / g. In a more specific embodiment, the first thermally conductive filler has an average particle size of at least 10 micrometers, the second thermally conductive filler has an average particle size between 1 micrometer and 10 micrometers, and the third thermally conductive filler has an average particle size of less than 1 micrometer.

[0010] In a more specific embodiment, the thermal interface material comprises: 2% to 10% by weight of low molecular weight silicone oil; 50% to 95% by weight of at least one thermally conductive filler; and 0.1% to 5% by weight of high molecular weight silicone oil; 0.1% to 5% by weight of solvent; 0.1% to 5% by weight of coupling agent; 0.1% to 1% by weight of crosslinking agent; 0.1% to 5% by weight of inhibitor; and 0.1% to 5% by weight of catalyst. In a more specific embodiment, the at least one thermally conductive filler comprises: 25% to 50% by weight of a first thermally conductive filler having a [0.1m] [temperature value missing]. 2 / g to 1.0m 2 Surface area between / g; 25 wt% to 50 wt% of a second thermally conductive filler, the second thermally conductive filler having a surface area between 0.5m² and 0.5g. 2 / g and 2.0m 2 The surface area is between / g; and 25% to 50% by weight of a third thermally conductive filler having a surface area of ​​5.0m². 2 / g and 10.0m 2 The surface area is between / g. In a more specific embodiment, the thermal interface material has a viscosity between 150 Pa·s and 650 Pa·s.

[0011] In one embodiment, a thermal interface material is provided. The thermal interface material comprises: a weight-average molecular weight (Mi) of less than 50,000 Daltons. w The composition includes: a low molecular weight silicone oil; a first thermally conductive filler, a second thermally conductive filler, and a third thermally conductive filler, wherein the first thermally conductive filler has a molecular weight of 0.1 m... 2 / g to 1.0m 2 The second thermally conductive filler is a metal oxide with a surface area between 0.5 m² / g and 0.5 m² / g. 2 / g and 2.0m 2 The third thermally conductive filler has a surface area between 5.0 m² / g and 6.5 m² / g. 2 / g and 10.0m 2 Metal oxides with a surface area between / g; and high molecular weight silicone oils, wherein the high molecular weight silicone oils comprise a weight-average molecular weight (M) of at least 60,000 Daltons. w The solvent comprises a vinyl-functionalized silicone oil; and a solvent having a boiling point between 60°C and 220°C and a viscosity between 0.2 cSt and 50 cSt.

[0012] In a more specific embodiment, the thermal interface material comprises: 2% to 10% by weight of low molecular weight silicone oil; and 25% to 50% by weight of a first thermally conductive filler having a density of 0.1 m. 2 / g to 1.0m 2 Surface area between / g; 25 wt% to 50 wt% of a second thermally conductive filler, the second thermally conductive filler having a surface area between 0.5m² and 0.5g. 2 / g and 2.0m 2 The surface area is between / g; and 25% to 50% by weight of a third thermally conductive filler having a surface area of ​​5.0m². 2 / g and 10.0m 2 Surface area between / g; 0.1 wt% to 5 wt% high molecular weight silicone oil; 0.1 wt% to 5 wt% solvent; 0.1 wt% to 5 wt% coupling agent; 0.1 wt% to 1 wt% crosslinking agent; 0.1 wt% to 5 wt% inhibitor; and 0.1 wt% to 5 wt% catalyst. In a more specific embodiment, the low molecular weight silicone oil comprises a vinyl-functionalized silicone oil, and the high molecular weight silicone oil is a vinyl silicone oil having a kinematic viscosity of 2,000,000 cSt. In a more specific embodiment, the first thermally conductive filler has an average particle size of at least 10 micrometers, the second thermally conductive filler has an average particle size between 1 micrometer and 10 micrometers, and the third thermally conductive filler has an average particle size of less than 1 micrometer. In a more specific embodiment, the thermal interface material has an exudation trace value between 1 mm and 5 mm and a flow rate between 20 g / min and 50 g / min. In a more specific embodiment, the thermal interface material has a viscosity between 150 Pa·s and 650 Pa·s.

[0013] In one embodiment, an electronic component is provided. The electronic component includes: a heat sink; an electronic chip; and a thermal interface material positioned between the heat sink and the electronic chip, the thermal interface material comprising: a weight-average molecular weight (Mi) of less than 50,000 Daltons. w Low molecular weight silicone oil; at least one having a molecular weight greater than 1.0 m 2 A thermally conductive filler with a surface area of ​​ / g; and a high molecular weight silicone oil, wherein the high molecular weight silicone oil comprises a weight-average molecular weight (Mn) of at least 60,000 Daltons. w Vinyl functional silicone oil.

[0014] In a more specific embodiment, the thermal interface material has a viscosity greater than 1500 Pa·s. In a more specific embodiment, the electronic component further comprises a solvent having a boiling point between 60°C and 220°C and a viscosity between 0.2 cSt and 50 cSt. In a more specific embodiment, the thermal interface material has a viscosity between 150 Pa·s and 650 Pa·s. In a more specific embodiment, at least one thermally conductive filler comprises a first thermally conductive filler, a second thermally conductive filler, and a third thermally conductive filler, wherein the first thermally conductive filler has a viscosity of 0.1 m...2 / g to 1.0m 2 The second thermally conductive filler is a metal oxide with a surface area between 0.5 m² / g and 0.5 m² / g. 2 / g and 2.0m 2 The third thermally conductive filler has a surface area between 5.0 m² / g and 6.5 m² / g. 2 / g and 10.0m 2 Metal oxides with a surface area between / g.

[0015] In a more specific embodiment, the electronic component further includes a heat sink positioned between the heat sink and the electronic chip, wherein a first surface layer contacts the surface of the electronic chip, and a second surface layer contacts the heat sink. In a more specific embodiment, the electronic component further includes a heat sink positioned between the heat sink and the electronic chip, wherein a first surface layer contacts the surface of the heat sink, and a second surface layer contacts the heat sink. Attached Figure Description

[0016] The above and other features and advantages of this disclosure, as well as the ways in which they are realized, will become more apparent and the invention itself will be better understood by referring to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: Figure 1 A typical electronic packaging structure is schematically illustrated. Figure 2 Comparative Example 1 relates to an oil seepage test, and a sample formed from Comparative Example 1 after the oil seepage test is shown. Figure 3A This relates to Example 1, and shows a sample formed from Example 1 after an oil seepage test; Figure 3B This relates to Example 1, and shows the back side of the sample formed by Example 1 after an oil seepage test; Figure 4 A flowchart illustrating a method for preparing a thermal interface material according to this disclosure is provided; and Figure 5 A dispenser apparatus according to an embodiment of the present disclosure is shown.

[0017] In several views, the corresponding index characters indicate the corresponding parts. The examples presented herein illustrate exemplary embodiments of the invention, and such examples should not be construed as limiting the scope of the invention in any way. Detailed Implementation

[0018] A. Thermal interface materials This invention relates to a thermal interface material (TIM) that can be used to transfer heat away from electronic components. In one exemplary embodiment, the TIM comprises at least one silicone oil, at least one catalyst, at least one thermally conductive filler having a relatively large surface area, a solvent, at least one inhibitor, and at least one crosslinking agent. The at least one thermally conductive filler reduces oil leakage of the TIM, and the solvent increases the flow rate of the TIM without offsetting the reduction in oil leakage achieved by the thermally conductive filler.

[0019] 1. silicone oil a. General description This invention provides a matrix for a thermally conductive ink (TIM) material comprising at least one low-molecular-weight silicone oil and at least one high-molecular-weight silicone oil. The silicone oil comprises one or more crosslinkable groups, such as vinyl, hydride, hydroxyl, and acrylate functional groups, crosslinked by a catalyst. In one embodiment, the one or more silicone oils comprise a first silicone oil and a second silicone oil, wherein the first silicone oil is a vinyl-functionalized silicone oil and the second silicone oil is a hydride-functionalized silicone oil. The silicone oil wets the thermally conductive filler and forms a distributable fluid for the TIM.

[0020] In one exemplary embodiment, the silicone oil includes silicone rubber, such as the KE series products purchased from Shin-Etsu Corporation, or SILBIONE purchased from Bluestar Corporation. ® Such as ELASTOSIL purchased from Wacker ® SilGel ® SILPURAN ® and SEMICOSIL ® Such as the Silopren purchased from Momentive. ® Such as Dow Corning, which was purchased from Dow Corning. ® Silastic ® XIAMETER ® Syl-off ® and SYLGARD ® Such as SQUARE, acquired from Square Silicone. ® Such as Andril, purchased from AB specialty Silicones ®Other polysiloxanes were purchased from Wacker, Shin-etsu, Dow Corning, Momentive, Bluestar, Runhe, AB Specialty Silicones, Gelest, and United Chemical Technologies.

[0021] b. Low molecular weight silicone oil 1. Vinyl functional silicone oil The thermally conductive ink (TIM) comprises a low weight-average molecular weight silicone oil as measured by gel permeation chromatography (GPC). The low molecular weight silicone oil wets the thermally conductive filler to form a distributable fluid for the TIM. Exemplary low molecular weight silicone oils may include vinyl silicone oils having the following general formula: Exemplary low molecular weight vinyl silicone oils may also contain a small amount of platinum catalyst.

[0022] Vinyl functional silicone oils comprise an organosilicon component having Si-CH=CH2 groups. Exemplary vinyl functional silicone oils include vinyl-terminated silicone oils, vinyl-grafted silicone oils in which Si-CH=CH2 groups are grafted onto polymer chains, and combinations thereof.

[0023] Exemplary vinyl-terminated silicone oils include vinyl-terminated polydimethylsiloxanes, such as DMS-V00 (weight-average molecular weight (M... w (186 Daltons), DMS-V03 (M) w (approximately 500 Daltons), DMS-V05 (M) w (approximately 800 Daltons), DMS-V21 (M w For approximately 6,000 Daltons ） DMS-V22 (M w (approximately 9400 Daltons), DMS-V25 (M) w (Approximately 17,200 Daltons), DMS-V25R (M) w (approximately 17,200 Daltons), DMS-V35 (M) w (approximately 49,500 Daltons), DMS-V35R (M) w (Approximately 49,500 Daltons), each purchased from Gelest, Inc. Exemplary vinyl-terminated silicone oils include vinyl-terminated diphenylsiloxane-dimethylsiloxane copolymers, such as PDV-0325 (M... w(approximately 15,500 Daltons), PDV-0331 (M) w (approximately 27,000 Daltons), PDV-0525 (M) w (approximately 14,000 Daltons), PDV-1625 (M) w (approximately 9,500 Daltons), PDV-1631 (M w (approximately 19,000 Daltons), PDV-2331 (M w Each of these silicone oils (approximately 12,500 Daltons) was purchased from Gelest, Inc. Exemplary vinyl-terminated silicone oils include vinyl-terminated polyphenylmethylsiloxanes, such as PMV-9925 (M...) purchased from Gelest, Inc. w (Approximately 2000-3000 Daltons). Exemplary vinyl-terminated silicone oils include vinyl-terminated diethylsiloxane-dimethylsiloxane copolymers, such as EDV-2025 (M...) purchased from Geles, Inc. w (Approximately 16,500-19,000 Daltons).

[0024] Exemplary vinyl-grafted silicone oils include vinylmethylsiloxane homopolymers, such as VMS-005 (M w (approximately 258-431 Daltons), VMS-T11 (M) w Both (approximately 1000-1500 Daltons) were purchased from Gelest, Inc. Exemplary vinyl-grafted silicone oils include vinylmethylsiloxane-dimethylsiloxane copolymers, such as trimethylsiloxy-terminated silicone oils, silanol-terminated silicone oils, and vinyl-terminated silicone oils.

[0025] In one exemplary embodiment, the vinyl-grafted silicone oil is a vinylmethylsiloxane terpolymer, including vinylmethylsiloxane-octylmethylsiloxane-dimethylsiloxane terpolymers such as VAT-4326 (M w (approximately 10,000-12,000 Daltons), or vinylmethylsiloxane-methoxypolyvinyloxypropylmethylsiloxane-dimethylsiloxane terpolymers such as VBT-1323 (M w (approximately 8,000-12,000 Daltons), or vinylmethylsiloxane-phenylmethylsiloxane-dimethylsiloxane (M w (Approximately 2,500-3,000 Daltons); they were each purchased from Gelest, Inc.

[0026] In one exemplary embodiment, the vinyl-functionalized silicone oil includes vinyl T resin or vinyl Q resin.

[0027] In one exemplary embodiment, the silicone oil is a vinyl-functionalized oil, such as RH-Vi303 and RH-Vi301 purchased from RUNHE, or Andril purchased from AB specialty Silicones. ® VS 200, Andril ® VS 1000.

[0028] Example low molecular weight silicone oil weight average molecular weight (M w The value can be as low as 50 Daltons, 500 Daltons, or 1,000 Daltons, or as high as 5,000 Daltons, 10,000 Daltons, or 50,000 Daltons, or any range between any two of the aforementioned values, such as between 50 Daltons and 50,000 Daltons, 500 Daltons and 50,000 Daltons, or between 1,000 Daltons and 50,000 Daltons.

[0029] As measured according to ASTM D445, the kinematic viscosity of the exemplary low molecular weight silicone oil can be as low as 0.5 cSt, 5 cSt, or 100 cSt, and as high as 5,000 cSt, 10,000 cSt, or 50,000 cSt, or any range defined between any two of the foregoing values, such as 0.5 cSt to 50,000 cSt, 5 cSt to 10,000 cSt, or 100 cSt to 5,000 cSt. In one exemplary embodiment, the exemplary low molecular weight silicone oil is a low molecular weight vinyl silicone oil with a kinematic viscosity of 1,000 cSt. In another exemplary embodiment, the exemplary low molecular weight silicone oil is a low molecular weight vinyl silicone oil with a kinematic viscosity greater than 1,500 cSt.

[0030] Based on the total weight of the TIM, the TIM contains one or more low molecular weight silicone oils in amounts as low as 0.1 wt%, 0.5 wt%, 0.67 wt%, 1 wt%, up to 3 wt%, 5 wt%, 10 wt%, 20 wt%, or in any range defined between any two of the foregoing values, such as 0.1 wt% to 15 wt%, 0.1 wt% to 10 wt%, or 0.67 wt% to 10 wt%.

[0031] c. High molecular weight silicone oil The TIM comprises a high molecular weight silicone oil as measured by gel permeation chromatography (GPC). The high molecular weight silicone oil serves to prevent the TIM from cracking during thermal cycling. Exemplary high molecular weight silicone oils may include vinyl silicone oils having the following general formula, which are similar to the low molecular weight silicone oils described above: Vinyl functional silicone oils comprise an organosilicon component having Si-CH=CH2 groups. Exemplary vinyl functional silicone oils include vinyl-terminated silicone oils, vinyl-grafted silicone oils in which Si-CH=CH2 groups are grafted onto polymer chains, and combinations thereof.

[0032] Exemplary vinyl-terminated silicone oils include vinyl-terminated polydimethylsiloxanes, such as DMS-V41 (M w (approximately 62,700 Daltons), DMS-V42 (M w (approximately 72,000 Daltons), DMS-V46 (M w (approximately 117,000 Daltons), DMS-V51 (M) w (approximately 140,000 Daltons) and DMS-V52 (M w (Totaling approximately 155,000 Daltons), each of them was purchased from Gelest, Inc.

[0033] Exemplary vinyl-grafted silicone oils include vinylmethylsiloxane-dimethylsiloxane copolymers, such as trimethylsiloxy-terminated silicone oils, silanol-terminated silicone oils, and vinyl-terminated silicone oils.

[0034] In one exemplary embodiment, the vinyl-grafted silicone oil is a vinylmethylsiloxane terpolymer. In one exemplary embodiment, the vinyl-functionalized silicone oil includes vinyl T resin or vinyl Q resin.

[0035] Another exemplary high molecular weight silicone oil may include a hydride-functionalized silicone oil having an organosilicon component and Si-H groups. Exemplary hydride-functionalized silicone oils include hydride-terminated silicone oils, hydride-grafted silicone oils in which Si-H groups are grafted onto the polymer chain, and combinations thereof.

[0036] In one exemplary embodiment, the hydride-terminated silicone oil is a hydride-terminated polydimethylsiloxane, such as DMS-H41 (M...) purchased from Geles, Inc. w (Approximately 62,700 Daltons). In one exemplary embodiment, the hydride-terminated silicone oil is a methylhydrosiloxane-dimethylsiloxane copolymer, such as trimethylsiloxy-terminated or hydride-terminated. Exemplary trimethylsiloxy-terminated copolymers include HMS-064 (M...) purchased from Geles, Inc. w (Approximately 60,000-65,000 Daltons).

[0037] Example low molecular weight silicone oil weight average molecular weight (M wThe values ​​can be as low as 100,000 Daltons, 300,000 Daltons, or 500,000 Daltons, or as high as 1,000,000 Daltons, 10,000,000 Daltons, or any range between any two of the aforementioned values, such as 100,000 Daltons to 100,000,000 Daltons, 300,000 Daltons to 10,000,000 Daltons, or 500,000 Daltons to 1,000,000 Daltons.

[0038] As measured according to ASTM D445, the kinematic viscosity of the exemplary high molecular weight silicone oil can be as low as 10,000 cSt, 20,000 cSt, 100,000 cSt, or as high as 1,000,000 cSt, 10,000,000 cSt, 100,000,000 cSt, or any range defined between any two of the foregoing values, such as 10,000 cSt to 100,000,000 cSt, 20,000 cSt to 10,000,000 cSt, or 100,000 cSt to 1,000,000 cSt. In one exemplary embodiment, the exemplary high molecular weight silicone oil is a high molecular weight vinyl silicone oil with a kinematic viscosity of 2,000,000 cSt.

[0039] Based on the total weight of the TIM, the TIM may contain one or more high molecular weight silicone oils in amounts as low as 0.01 wt%, 0.1 wt%, 0.25 wt%, 0.5 wt%, 0.67 wt%, 0.75 wt%, and as high as 1 wt%, 1.5 wt%, 2 wt%, 5 wt%, or any range defined between any two of the foregoing values, such as 0.1 wt% to 5 wt%, 0.1 wt% to 1 wt%, or 0.25 wt% to 0.67 wt%. In one exemplary embodiment, the TIM contains approximately 1.5 wt% of high molecular weight silicone oil.

[0040] 2. catalyst The TIM also includes one or more catalysts for catalytic addition reactions. Exemplary catalysts include platinum-containing and rhodium-containing materials. Exemplary platinum-containing catalysts may have the following general formula: Exemplary platinum-containing catalysts include: platinum cyclovinylmethylsiloxane complexes (Ashby Karstedt catalyst), platinum carbonyl cyclovinylmethylsiloxane complexes (Ossko catalyst), platinum divinyltetramethyldisiloxane dimethyl fumarate complexes, platinum divinyltetramethyldisiloxane dimethyl maleate complexes, etc. Exemplary platinum carbonyl cyclovinylmethylsiloxane complexes include SIP6829.2, exemplary platinum divinyltetramethyldisiloxane complexes include SIP6830.3 and SIP6831.2, and exemplary platinum cyclovinylmethylsiloxane complexes include SIP6833.2; all of these were purchased from Geles, Inc. Other exemplary platinum-containing catalysts include Catalyst OL, purchased from Wacker Chemie AG, and PC065, PC072, PC073, PC074, PC075, PC076, PC085, PC086, PC087, and PC088, purchased from United Chemical Technologies Inc.

[0041] Exemplary rhodium-containing materials include tris(dibutyl sulfide) rhodium trichloride, product code INRH078, purchased from Geles, Inc.

[0042] Not wanting to be bound by any particular theory, the reaction of platinum catalysts with vinyl silicone oil and hydrogen-containing silicone oil is as follows.

[0043] Based on the total weight of the silicone oil, the TIM may contain one or more catalysts in amounts as low as 5 ppm, 10 ppm, 15 ppm, 20 ppm, up to 25 ppm, 30 ppm, 40 ppm, 50 ppm, 100 ppm, 200 ppm, 500 ppm, 1000 ppm, or within any range defined between any two of the foregoing values, such as 10 ppm to 30 ppm, 20 ppm to 100 ppm, or 5 ppm to 500 ppm.

[0044] In one exemplary embodiment, the catalyst is provided in the form of a mixture with one or more silicone oils. In one exemplary embodiment, a platinum-containing catalyst is mixed with a functional silicone oil, such as KE-1012-A, KE-1031-A, KE-109E-A, KE-1051J-A, KE-1800T-A, KE1204A, and KE1218A purchased from Shin-Etsu Corporation, or SILBIONE purchased from Bluestar Corporation. ®RT Gel 4725 SLD A, such as SilGel purchased from Wacker. ® 612 A, ELASTOSIL ® LR 3153A, ELASTOSIL ® LR 3003A, ELASTOSIL ® LR 3005A, SEMICOSIL ® 961A, SEMICOSIL ® 927A, SEMICOSIL ® 205A, SILPURAN ® 2440, such as the Silopren purchased from Momentive. ® LSR 2010A, such as XIAMETER purchased from Dow Corning. ® RBL-9200 A, XIAMETER ® RBL-2004 A, XIAMETER ® RBL-9050 A, XIAMETER ® RBL-1552 A, Silastic ® FL 30-9201 A, Silastic ® 9202 A, Silastic ® 9204 A, Silastic ® 9206 A, SYLGARD ® 184A, Dow Corning ® QP-1 A, Dow Corning ® C6 A、Dow Corning ® CV9204 A.

[0045] Based on the total weight of the TIM, the TIM may contain catalyst in amounts as low as 0.01 wt%, 0.1 wt%, 0.2 wt%, and as high as 0.3 wt%, 0.4 wt%, 0.5 wt%, or any range defined between any two of the foregoing values, such as 0.01 wt% to 0.5 wt%, 0.01 wt% to 0.4 wt%, or 0.01 wt% to 0.3 wt%. In one exemplary embodiment, the TIM contains about 0.01 wt% of catalyst. In another exemplary embodiment, the TIM contains about 0.3 wt% of catalyst.

[0046] In another embodiment, a platinum-containing catalyst is mixed with a high molecular weight vinyl-functionalized silicone oil.

[0047] 3. Thermally conductive filler TIM comprises one or more thermally conductive fillers. The thermally conductive filler provides a thermally conductive material to conduct heat through the thermal interface material. Exemplary thermally conductive fillers include metals, alloys, nonmetals, metal oxides, and ceramics, as well as combinations thereof. Metals include, but are not limited to, aluminum, copper, silver, zinc, nickel, tin, indium, and lead. Nonmetals include, but are not limited to, carbon, graphite, carbon nanotubes, carbon fibers, graphene, boron nitride, and silicon nitride. Metal oxides or ceramics include, but are not limited to, alumina (aluminum oxide), aluminum nitride, boron nitride, zinc oxide, and tin oxide.

[0048] Based on the total weight of the TIM, the TIM may contain one or more thermally conductive fillers in amounts as low as 10 wt%, 20 wt%, 25 wt%, 50 wt%, up to 75 wt%, 80 wt%, 85 wt%, 90 wt%, 95 wt%, 97 wt%, or any range between any two of the foregoing values, such as 10 wt% to 95 wt%, 20 wt% to 95 wt%, or 25 wt% to 90 wt%.

[0049] The average particle size of the exemplary thermally conductive filler can be as low as 0.1 micrometer, 1 micrometer, or 10 micrometer, or as high as 50 micrometer, 75 micrometer, or 100 micrometer, or any range defined between any two of the foregoing values, such as 0.1 micrometer to 100 micrometer, 0.1 micrometer to 75 micrometer, or 0.1 micrometer to 50 micrometer.

[0050] As measured by the Brunauer-Emmett-Teller (BET) procedure, ASTM C1274-2012, or ASTM B922-2010, the surface area of ​​exemplary thermally conductive fillers can be as low as 0.10 m². 2 / g, 0.50m 2 / g, 1.0m 2 / g, up to 5.0m 2 / g, 7.0m 2 / g, 8.5m 2 / g, 10.0m 2 / g, or any range between any two of the aforementioned values, such as 0.1m 2 / g to 0.5m 2 / g, 0.10m 2 / g to 10.0m 2 / g, or 0.10m 2 / g to 8.5m 2 / g. In one exemplary embodiment, the exemplary thermally conductive filler has 0.15m 2 / g surface area. In another embodiment, an exemplary thermally conductive filler has a surface area of ​​1.1m.2 / g surface area. In yet another exemplary embodiment, the exemplary thermally conductive filler has a surface area of ​​7.6m². 2 / g of surface area.

[0051] To avoid being bound by any particular theory, it is believed that the higher surface area thermally conductive fillers used in TIM control oil leakage because such high surface area fillers reduce the flow rate of the thermal gel (i.e., make it more viscous). Furthermore, larger surface area fillers can absorb oil molecules, and due to the intermolecular forces associated with absorption, the oil cannot flow freely from the TIM, thus reducing oil leakage. Additionally, the use of smaller fillers results in shorter distances between the fillers and the formation of a capillary network within the TIM. This capillary network absorbs oil and therefore reduces oil leakage.

[0052] In one exemplary embodiment, the TIM may include a first thermally conductive filler, a second thermally conductive filler, and a third thermally conductive filler, wherein the surface area of ​​the first thermally conductive filler is as low as 0.1 m². 2 / g, 0.2m 2 / g, 0.5m 2 / g, up to 0.6m 2 / g, 0.8m 2 / g, 1.0m 2 / g, or any range defined between them, the surface area of ​​the second thermally conductive filler is as low as 0.5m². 2 / g, 0.7m 2 / g, 0.9m 2 / g, up to 1.5m 2 / g, 1.7m 2 / g, 2.0m 2 / g, or any range defined between them, and the surface area of ​​the third thermally conductive filler is as low as 5.0m². 2 / g, 6.0m 2 / g, 7.0m 2 / g, up to 8.0m 2 / g, 9.0m 2 / g, 10.0m 2 / g, or any range in between.

[0053] In one exemplary embodiment, the TIM comprises, relative to the total TIM composition, a first thermally conductive filler in amounts as low as 20 wt%, 25 wt%, or 30 wt%, and as high as 45 wt%, 50 wt%, or 60 wt%, or within any range defined between any two of the foregoing values, such as 20 wt% to 60 wt%, 25 wt% to 50 wt%, or 30 wt% to 45 wt%. The average particle size of the first thermally conductive filler is as low as 10 micrometers, 35 micrometers, or 40 micrometers, and as high as 45 micrometers, 50 micrometers, or 60 micrometers, or within any range defined between any two of the foregoing values, such as 10 micrometers to 60 micrometers, 10 micrometers to 50 micrometers, or 10 micrometers to 45 micrometers. The surface area of ​​the first thermally conductive filler is as low as 0.1 m². 2 / g, 0.2m 2 / g, 0.5m 2 / g, up to 0.6m 2 / g, 0.8m 2 / g, 1.0m 2 / g, or any range defined between them, such as 0.1m 2 / g to 1.0m 2 / g, 0.1m 2 / g to 0.8m 2 / g, or 0.1m 2 / g to 0.6m 2 / g.

[0054] Relative to the total TIM composition, the exemplary TIM may further comprise a second thermally conductive filler in amounts as low as 20 wt%, 25 wt%, or 30 wt%, and as high as 45 wt%, 50 wt%, or 60 wt%, or within any range defined between any two of the foregoing values, such as 20 wt% to 60 wt%, 25 wt% to 50 wt%, or 25 wt% to 45 wt%. The average particle size of the second thermally conductive filler is as low as 1 μm, 3 μm, or 5 μm, and as high as 10 μm, 15 μm, or 20 μm, or within any range defined between any two of the foregoing values, such as 1 μm to 20 μm, 3 μm to 15 μm, or 5 μm to 15 μm. The surface area of ​​the second thermally conductive filler is as low as 0.5 m². 2 / g, 0.7m 2 / g, 0.9m 2 / g, up to 1.5m 2 / g, 1.7m 2 / g, 2.0m 2 / g, or any range defined between them, such as 0.5m 2 / g to 2.0m 2 / g, 0.7m 2 / g to 1.7m 2 / g, or 0.9m2 / g to 1.5m 2 / g.

[0055] Relative to the total TIM composition, the exemplary TIM further comprises a third thermally conductive filler in amounts as low as 20 wt%, 25 wt%, or 30 wt%, and as high as 45 wt%, 50 wt%, or 60 wt%, or within any range defined between any two of the foregoing values, such as 20 wt% to 60 wt%, 25 wt% to 50 wt%, or 30 wt% to 45 wt%. The average particle size of the third thermally conductive filler is as low as 0.1 μm, 0.3 μm, or 0.5 μm, and as high as 1 μm, 1.5 μm, or 2 μm, or within any range defined between any two of the foregoing values, such as 0.1 μm to 2 μm, 0.3 μm to 1.5 μm, or 0.5 μm to 1 μm. The surface area of ​​the third thermally conductive filler is as low as 5.0 m². 2 / g, 6.0m 2 / g, 7.0m 2 / g, up to 8.0m 2 / g, 9.0m 2 / g, 10.0m 2 / g, or any range defined between them, such as 5.0m 2 / g to 10m 2 / g, 6.0m 2 / g to 9.0m 2 / g, or 7.0m 2 / g to 8.0m 2 / g.

[0056] An exemplary TIM may include a single thermally conductive filler, wherein the single thermally conductive filler is one of a first thermally conductive filler, a second thermally conductive filler, or a third thermally conductive filler as described herein. In another exemplary TIM, the TIM includes a first thermally conductive filler and a second thermally conductive filler, wherein the first thermally conductive filler and the second thermally conductive filler are, as described herein, a first thermally conductive filler and a third thermally conductive filler, or a second thermally conductive filler and a third thermally conductive filler. In yet another exemplary TIM, the TIM includes a first thermally conductive filler, a second thermally conductive filler, and a third thermally conductive filler as described herein.

[0057] Exemplary thermally conductive fillers include alumina.

[0058] 4. Addition inhibitors TIM contains one or more addition inhibitors for inhibiting or limiting the crosslinking of silicone oil. The addition inhibitor forms a complex with the catalyst to stop the reaction of the silicone oil. The addition inhibitor contains at least one alkynyl compound, and optionally, the addition inhibitor also contains a polyvinylfunctional polysiloxane.

[0059] Exemplary addition inhibitors include alkynols, such as 1-ethynyl-1-cyclohexanol, 2-methyl-3-butyn-2-ol, 2-phenyl-3-butyn-2-ol, 2-ethynylisopropanol, 2-ethynyl-butane-2-ol, and 3,5-dimethyl-1-hexyn-3-ol; silylated alkynols, such as trimethyl(3,5-dimethyl-1-hexyn-3-oxy)silane, dimethyl-bis(3-methyl-1-butyn-oxy)silane, methylvinylbis(3-methyl-1-butyn-3-oxy)silane, and ((1,1-dimethyl-2-propynyl)oxy)trimethylsilane; and unsaturated carboxylic acid esters, such as diallyl maleate, dimethyl maleate, diethyl fumarate, diallyl fumarate, and bis-2-methoxy-1-methylethyl maleate, maleic acid Monooctyl ester, monoisooctyl maleate, monoallyl maleate, monomethyl maleate, monoethyl fumarate, monoallyl fumarate, 2-methoxy-1-methylethyl maleate; fumarate / alcohol mixtures, such as those where the alcohol is selected from benzyl alcohol or a mixture of 1-octanol and ethynylcyclohexyl-1-ol; conjugated enynes, such as 2-isobutyl-1-buten-3-yne, 3,5-dimethyl-3-hexen-1-yne, 3-methyl-3-penten-1-yne, 3-methyl-3-hexen-1-yne, 1-ethynylcyclohexene, 3-ethyl-3-buten-1-yne and 3-phenyl-3-buten-1-yne; vinylcyclosiloxanes, such as 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, and mixtures of conjugated enynes and vinylcyclosiloxanes. In one exemplary embodiment, the addition inhibitor is selected from 2-methyl-3-butyn-2-ol or 3-methyl-1-pentyn-3-ol.

[0060] In some exemplary embodiments, the addition inhibitor also includes a polyvinylfunctional polysiloxane. An exemplary polyvinylfunctional polysiloxane is a vinyl-terminated polydimethylsiloxane of ethynylcyclohexanol, such as Pt inhibitor 88, available from Wacker Chemie AG. Without being bound by any particular theory, it is known that platinum catalysts form complexes with ethynylcyclohexanol and vinyl-terminated polydimethylsiloxanes, as shown below.

[0061] .

[0062] It is believed that the formation of the complex reduces the catalyst activity at room temperature, thus preserving the dispensability and wettability of the TIM. At higher curing step temperatures, Pt is released from the complex and facilitates the hydrosilylation of vinyl-functionalized and hydride-functionalized silicone oils, providing better control over "crosslinking".

[0063] In some exemplary embodiments, based on the total weight of the TIM, the TIM may contain one or more addition inhibitors in amounts as low as 0.01 wt%, 0.02 wt%, 0.05 wt%, 0.1 wt%, and 0.15 wt%, and as high as 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.5 wt%, 1 wt%, 3 wt%, and 5 wt%, or any range defined between any two of the foregoing values, such as 0.01 wt% to 1 wt%, 0.01 wt% to 0.5 wt%, or 0.01 wt% to 3 wt%. In one exemplary embodiment, the TIM contains 0.1 wt% of the addition inhibitor. In another exemplary embodiment, the TIM contains 0.01 wt% of the addition inhibitor.

[0064] Without being bound by any particular theory, it is believed that, in the absence of addition inhibitors, vinyl-functionalized silicone oils react very rapidly with hydride-functionalized silicone oils based on the addition-hydrosilanization mechanism to form a solid phase that cannot be automatically partitioned by typical methods.

[0065] In one exemplary embodiment, the addition inhibitor is mixed with a functional silicone oil, such as KE-1056, KE-1151, KE-1820, KE-1825, KE-1830, KE-1831, KE-1833, KE-1842, KE-1884, KE-1885, KE-1886, FE-57, FE-61 purchased from Shin-Etsu, or Syl-off purchased from Dow Corning. ® 7395, Syl-off ® 7610, Syl-off ® 7817, Syl-off ® 7612, Syl-off ® 7780.

[0066] 5. Coupling agent In an exemplary embodiment, the thermal gel comprises one or more coupling agents that interact with both the filler and the polymer matrix of the silicone oil to promote strong adhesion at the interface of the two materials. This facilitates the separation of filler particle aggregates and the dispersion of filler particles within the polymer matrix, allowing the thermally conductive filler to better adhere to the polyol polymer matrix. Exemplary coupling agents include silane coupling agents and organometallic compounds, such as titanate coupling agents and zirconate coupling agents. Exemplary silane coupling agents include silane coupling agents having aliphatic groups. Exemplary coupling agents include 2,2-(bis-2-propenol-methyl)butanol-tris(dioctyl)pyrophosphate-O-titanium IV; 2-propanol-tris(dioctyl)-pyrophosphate-O-titanium IV with 1 mole of diisooctyl phosphite; bis(dioctyl)pyrophosphate-O-oxoethylene glycol-titanium IV (addition) bis(dioctyl)(hydro)phosphite-O; bis(dioctyl)pyrophosphate-O-ethylene glycol-titanium IV (addition) bis(dioctyl)hydrophosphite; 2,2-(bis-2-propenol-methyl)butanol-tris(diisooctyl)pyrophosphate-O-zirconium IV; 2,2-bis(2-propenol-methyl)butanol-cyclo[2,2-(bis-2-propenol-methyl)butanol-]-pyrophosphate-O,O-zirconium IV and hexadecyltrimethoxysilane. In another exemplary embodiment, the coupling agent is KR-TTS purchased from Kenrich Chemical Company.

[0067] In some exemplary embodiments, based on the total weight of the thermal interface material, the thermal gel contains one or more coupling agents in amounts as low as 0.1 wt%, 0.2 wt%, 0.3 wt%, up to 0.5 wt%, 1.0 wt%, 1.5 wt%, 2.0 wt%, or any range defined between any two of the foregoing values, such as 0.1 wt% to 2.0 wt%, 0.2 wt% to 1.5 wt%, or 0.3 wt% to 0.5 wt%.

[0068] 6. Crosslinking agent In an exemplary embodiment, the TIM includes a crosslinking agent to enable crosslinking between silicone oils. Exemplary crosslinking agents include hydrogen-containing silicone oils. Exemplary crosslinking agents include Andisil XL-1B, Andisil XL-10, Andisil XL-11, Andisil XL 12, Andisil XL-13, and Andisil XL-17.

[0069] In some exemplary embodiments, based on the total weight of the thermogel, the TIM contains one or more crosslinking agents in amounts as low as 0.10%, 0.20% by weight, 0.30% by weight, up to 0.4% by weight, 0.60% by weight, 0.70% by weight, 1.0% by weight, or within any range defined between any two of the foregoing values, such as 0.10% by weight to 1.0% by weight, 0.20% by weight to 0.70% by weight, or 0.30% by weight to 0.60% by weight.

[0070] 7. solvent In an exemplary embodiment, the TIM contains a solvent to increase the flow rate of the TIM. Exemplary solvents include: hydrocarbon solvents such as toluene, xylene, p-xylene, m-xylene, mesitylene, naphtha H, naphtha A, Isopar H and other paraffinic oils and isoparaffinic fluids; alkanes such as pentane, hexane, isohexane, heptane, nonane, octane, dodecane, 2-methylbutane, hexadecane, tridecane, pentadecane, cyclopentane, 2,2,4-trimethylpentane; petroleum ether; halogenated hydrocarbons such as chlorinated hydrocarbons, nitrated hydrocarbons, benzene, 1,2-dimethylbenzene, 1,2,4-trimethylbenzene, mineral oil, kerosene, isobutylbenzene, methylnaphthalene, ethyltoluene, and light petroleum.

[0071] The exemplary solvents have boiling points as low as 60°C, 90°C, 110°C, and as high as 130°C, 180°C, 220°C, or any range defined between any two of the foregoing values, such as 60°C to 220°C, 90°C to 180°C, or 110°C to 130°C.

[0072] The exemplary solvents have viscosities as low as 0.2 cSt, 1 cSt, 2 cSt, and as high as 5 cSt, 10 cSt, 50 cSt, or any range defined between any two of the aforementioned values, such as 0.2 cSt to 50 cSt, 1 cSt to 10 cSt, or 2 cSt to 5 cSt.

[0073] In some exemplary embodiments, based on the total weight of the formulation, the thermal interface material may contain one or more solvents in amounts as low as 0.1 wt%, 0.2 wt%, 0.3 wt%, up to 5 wt%, 10 wt%, 20 wt%, or any range defined between any two of the foregoing values, such as 0.1 wt% to 20 wt%, 0.1 wt% to 10 wt%, or 0.1 wt% to 5 wt%.

[0074] 6. Exemplary formulations of thermal interface materials In a first non-limiting exemplary embodiment, the TIM comprises: a first low molecular weight silicone oil, as low as 2 wt%, 3 wt%, 4 wt%, and as high as 8 wt%, 9 wt%, 10 wt%, or any range defined between any two of the foregoing values, such as about 2 wt% to about 10 wt%; a high molecular weight silicone oil, as low as 0.1 wt%, 1 wt%, 2 wt%, and as high as 3 wt%, 4 wt%, 5 wt%, or any range defined between any two of the foregoing values, such as about 0.1 wt% to about 5 wt%; and a coupling agent, as low as 0.1 wt%, 1 wt%, 2 wt%, and as high as... 3 wt%, 4 wt%, 5 wt%, or any range within any two of the foregoing values, such as about 0.1 wt% to about 5 wt%; crosslinking agent, as low as 0.1 wt%, 0.2 wt%, 0.3 wt%, and as high as 0.8 wt%, 0.9 wt%, 1.0 wt%, or any range within any two of the foregoing values, such as about 0.1 wt% to about 1 wt%; catalyst, as low as 0.1 wt%, 1 wt%, 2 wt%, and as high as 3 wt%, 4 wt%, 5 wt%, or any range within any two of the foregoing values, such as about 0.1 wt%. % to about 5% by weight; inhibitors, as low as 0.1% by weight, 1% by weight, 2% by weight, and as high as 3% by weight, 4% by weight, 5% by weight, or any range within any two of the foregoing values, such as about 0.1% by weight to about 5% by weight; first thermally conductive filler, as low as 25% by weight, 30% by weight, 35% by weight, and as high as 40% by weight, 45% by weight, 50% by weight, or any range within any two of the foregoing values, such as about 25% by weight to about 50% by weight; second thermally conductive filler, as low as 25% by weight, 30% by weight, 35% by weight, and as high as 40% by weight, 45% by weight The amount, 50% by weight, or any range between any two of the foregoing values, such as about 25% by weight to about 50% by weight; the third thermally conductive filler, as low as 25% by weight, 30% by weight, 35% by weight, or as high as 40% by weight, 45% by weight, 50% by weight, or any range between any two of the foregoing values, such as about 25% by weight to about 50% by weight; and the solvent, as low as 0.1% by weight, 1% by weight, 2% by weight, or as high as 3% by weight, 4% by weight, 5% by weight, or any range between any two of the foregoing values, such as about 0.1% by weight to about 5% by weight.

[0075] In a second non-limiting exemplary embodiment, the TIM comprises: a first low molecular weight silicone oil, ranging from as low as 0.1 wt%, 1 wt%, 2 wt% to as high as 13 wt%, 14 wt%, 15 wt%, or within any range defined between any two of the foregoing values, such as from about 0.1 wt% to about 15 wt%; a high molecular weight silicone oil, ranging from as low as 0.1 wt%, 1 wt%, 2 wt% to as high as 3 wt%, 4 wt%, 5 wt%, or within any range defined between any two of the foregoing values, such as from about 0.1 wt% to about 5 wt%; a first thermally conductive filler, ranging from as low as 25 wt%, 30 wt%, 35 wt% to as high as 40 wt%, 45 wt%, 50 wt%, or within any range defined between any two of the foregoing values, such as from about 25 wt% to about 50 wt%; and a second thermally conductive filler, ranging from as low as 25 wt%, 30 wt%, 35 wt% to as high as 40 wt%, 45 wt%, 50 wt%, or... The following are examples of the following: a third thermally conductive filler, ranging from as low as 25 wt%, 30 wt%, 35 wt% to as high as 40 wt%, 45 wt%, 50 wt%, or ranging from as low as 25 wt% to as high as 50 wt% within any range between any two of the aforementioned values; an addition inhibitor, ranging from as low as 0.1 wt%, 1 wt%, 2 wt% to as high as 3 wt%, 4 wt%, 5 wt%, or ranging from as low as 0.1 wt% to as high as 5 wt% within any range between any two of the aforementioned values; an addition catalyst, ranging from as low as 0.1 wt%, 1 wt%, 2 wt% to as high as 3 wt%, 4 wt%, 5 wt%, or ranging from as low as 0.1 wt% to as high as 5 wt% within any range between any two of the aforementioned values; and a crosslinking agent, ranging from as low as 0.1 wt% to as high as 1 wt% within any range between any two of the aforementioned values.

[0076] 7. Exemplary properties of thermal interface materials In some exemplary embodiments, the thermal interface material described above exhibits excellent resistance to oil leakage while simultaneously increasing the flow rate of the TIM. Oil leakage is the distance oil leaks from the TIM and is generally understood to be negatively correlated with the viscosity of the thermal interface material. That is, generally, the higher the viscosity of the TIM, the less oil leakage occurs.

[0077] The exemplary thermal interface material is curable to form a solid pad for use with electronic components. For example, the exemplary thermal interface material has a curing time at room temperature ranging from 1 hour, 5 hours, or 24 hours to 2 days, 3 days, or 5 days, or any range defined between any two of the foregoing values, such as between 1 hour and 5 days, between 5 hours and 3 days, or between 24 hours and 1 day. Higher temperatures will accelerate the curing time of the exemplary thermal interface material. For example, at an ambient temperature of 100°C, the curing time of the exemplary thermal interface material is between 1 minute and 30 minutes.

[0078] The thickness of the exemplary thermal interface material is as low as 0.03 mm, 0.05 mm, 0.07 mm, and as high as 0.1 mm, 0.5 mm, 1 mm, or any range defined between any two of the aforementioned values, such as 0.03 mm to 1 mm, 0.05 mm to 0.5 mm, or 0.07 mm to 0.1 mm.

[0079] At 23℃ and 10s -1 At the shear rate described above, the viscosity of the exemplary thermal interface material without added solvent is as low as 1000 Pa·s, 1500 Pa·s, 2000 Pa·s, and as high as 2500 Pa·s, 3000 Pa·s, 3500 Pa·s, or any range defined between any two of the aforementioned values, such as between 1000 Pa·s and 3500 Pa·s, between 1500 Pa·s and 3000 Pa·s, or between 2000 Pa·s and 2500 Pa·s.

[0080] At 25℃ and 10s -1 At the shear rate described above, the viscosity of the exemplary thermal interface material containing the added solvent is as low as 150 Pa·s, 200 Pa·s, 250 Pa·s, 300 Pa·s, and as high as 500 Pa·s, 550 Pa·s, 600 Pa·s, 650 Pa·s, or any range defined between any two of the aforementioned values, such as between 150 Pa·s and 650 Pa·s, or between 200 Pa·s and 600 Pa·s.

[0081] Exemplary TIMs have leaching values ​​as low as 0.25mm, 0.50mm, 1.0mm, and as high as 1.25mm, 1.40mm, 1.50mm, or any range defined between any two of the aforementioned values, such as 0.25mm to 1.50mm, 0.50mm to 1.40mm, or 1.0mm to 1.25mm.

[0082] The exemplary TIM has a flow rate as low as 20 g / min, 25 g / min, 30 g / min, and as high as 35 g / min, 40 g / min, 50 g / min, or any range defined between any two of the foregoing values, such as 20 g / min to 50 g / min, 25 g / min to 40 g / min, or 30 g / min to 35 g / min.

[0083] B. Methods for forming thermal interface materials In some exemplary embodiments, TIM is prepared by mixing individual components, excluding the solvent, in a high-speed mixer and blending the composition together. The blended composition can then be applied directly to a substrate without baking.

[0084] More specifically, see reference Figure 4 An exemplary method for forming TIM 100 is shown. In step 102, a water cooling system / reaction vessel is turned on, and high molecular weight silicone oil, low molecular weight silicone oil, inhibitor, catalyst, and crosslinking agent are added under mixing. In an exemplary embodiment, the mixture is mixed at 30 rpm for 10 minutes. Then, in step 104, a first thermally conductive filler is added under mixing. In an exemplary embodiment, the mixture is mixed at 10 rpm for 5 minutes. In step 106, a second thermally conductive filler is added under mixing. In an exemplary embodiment, the mixture is mixed at 10 rpm for 10 minutes. In step 108, a portion of a third thermally conductive filler is added under mixing. In an exemplary embodiment, half of the third thermally conductive filler is added, and the mixture is mixed at 10 rpm for 10 minutes. In step 110, the remaining portion of the third thermally conductive filler is added under mixing. In an exemplary embodiment, a second half of the third thermally conductive filler is added, and the mixture is mixed at 10 rpm for 10 minutes and then mixed at 54 rpm for 1 hour.

[0085] In step 112, solvent is added to the reaction vessel and mixing continues. In an exemplary embodiment, half of the third thermally conductive packing is added, and the mixture is mixed at 10 rpm for 30 minutes. In step 114, the vacuum pump of the reaction vessel is turned on and mixing continues. In an exemplary embodiment, the mixture is mixed at 54 rpm for 30 minutes. In step 116, the vacuum pump is turned off and the mixture is transferred to the venting device. Finally, in step 118, the vacuum pump is turned on to remove air from the TIM, then the vacuum pump is turned off and the resulting material is compressed into syringe 50 (…). Figure 5 )middle.

[0086] C. Application of thermal interface materials Refer again Figure 1In some exemplary embodiments, the thermal interface material is positioned as TIM 18 between the electronic component 12 and the heat sink 14, as shown in TIM 18. In some exemplary embodiments, the thermal interface material is positioned as TIM 2 between the heat sink 14 and the heat fin 16, as shown in TIM 20. In some exemplary embodiments, the thermal interface material is positioned as TIM 1.5 (not shown) between the electronic component 12 and the heat sink 16. Example

[0087] Example 1 A thermal interface material was prepared according to the formulation provided in Table 1 (Example 1). The properties of Example 1 were then compared with those of Comparative Example 1 (Comparative Example 1). Comparative Example 1 was also an organosilicon-based TIM with Al2O3 filler and not fully cured.

[0088] Table 1: Formulation of Example 1 (wt%) <![CDATA[ Components ]]> <![CDATA[ weight% ]]> Low MW silicone oil 5.9 High MW silicone oil 1.5 Silane coupling agents 0.3 Hydrogen-containing silicone oil 0.6 Platinum addition catalyst 0.3 Addition inhibitors 0.1 Thermally conductive filler A 30 Thermally conductive filler B 27 Thermally conductive filler C 34 Volatile solvents 0.3

[0089] In Example 1, the low molecular weight (MW) silicone oil is a low molecular weight liquid silicone oil having vinyl functional groups. The molecular weight of the low MW silicone oil is less than 50,000 Daltons. The high MW silicone oil has a molecular weight greater than 100,000 Daltons. The silane coupling agent used is hexadecyltrimethoxysilane.

[0090] In addition, a hydrogen-containing silicone oil was used as a crosslinking agent, specifically Andisil XL 12 purchased from AB Specialty Silicones Nantong Co., Ltd. The catalyst was an addition platinum catalyst purchased from Wacker Chemie AG, and the addition inhibitor was Pt inhibitor 88 purchased from Wacker Chemie AG. Thermally conductive filler A comprised alumina particles with a diameter of approximately 10 micrometers. Thermally conductive filler B comprised alumina particles with a diameter of approximately 5 micrometers, and thermally conductive filler C comprised alumina particles with a diameter of approximately 0.6 micrometers. The total surface area of ​​all particles in thermally conductive fillers AC was approximately 1.25 m². 2 / g. Finally, the solvent used was Isopar H, purchased from Multisol Limited.

[0091] To prepare the formulation of Example 1, the organic components, excluding the volatile solvent, were mixed and blended using a high-speed mixer. A thermally conductive filler was then added, followed by blending. Finally, the volatile solvent was added and blended again to obtain the formulation of Example 1.

[0092] The preparation is then filled into a 10 cubic centimeter syringe 50 connected to an automatic dispenser tool 52. Figure 5 The mixture can be removed from the syringe 50 by the air pressure generated by the dispenser tool 52. The dispenser tool 52 also controls the orifice diameter. In fact, the dispenser tool 52 controls the dispensing rate of the mixture from the syringe 50 by changing two parameters—the orifice diameter and the air pressure. The formulation was dispensed at a pressure of 0.6 MPa to test the flow rate.

[0093] To measure the flow rate of the TIM sample, a nozzleless 30 cubic centimeter (cc) syringe 50 was used, and the TIM sample was dispensed for 1 minute at a pressure of 0.6 MPa via a dispenser tool 52. After 1 minute, the dispensed TIM sample was weighed. The measured flow rate of the formulation of Example 1 was 31 g / min.

[0094] The formulation was then printed as a gel onto an A4 sheet of paper. The formulation dimensions were 25.4 mm × 25.4 mm × 1.5 mm. The formulation from Example 1 was then placed at room temperature until the oil seepage from the formulation ceased to swell. The distance from the formulation was then measured to determine the distance of the oil seepage marks. Figure 3A and Figure 3B As shown, the oil seepage mark in Example 1 was approximately 1.2 mm. In contrast, as... Figure 2 As shown, the formulation of Comparative Example 1 had an exudate mark greater than 3.5 mm.

[0095] To avoid being bound by any particular theory, it is believed that adding high surface area fillers reduces exudation in TIM. These fillers also reduce the flow rate of TIM (i.e., increase viscosity). However, solvents are added to increase the flow rate of TIM to improve its suitability. Furthermore, minimal solvent addition (e.g., less than 0.5% by weight) prevents the solvent from negating the beneficial effects of reduced exudation achieved by adding high surface area fillers to the TIM.

[0096] Furthermore, oil exudation is a slow process—it can be observed after at least 6 hours. In contrast, the solvent used is highly volatile (i.e., evaporates rapidly), causing it to completely evaporate during oil exudation (e.g., within about 1 or 2 hours). Therefore, when dispensing TIM, adding solvent increases the flow rate of TIM, but once dispensed and after a period of time (e.g., about 2 hours), the solvent will completely evaporate from the TIM and will not affect the oil exudation characteristics of the TIM.

[0097] As used in this article, the phrase “any range between any two of the preceding values” literally means that any range can be selected from any two values ​​listed before such a phrase, regardless of whether these values ​​are in the lower or higher part of the list. For example, a pair of values ​​can be selected from two lower values, two higher values, or a lower value and a higher value.

[0098] Although the invention has been described with exemplary design, further modifications may be made to the invention within the spirit and scope of this disclosure. Therefore, this application is intended to cover any variations, uses, or adaptations of the invention using its general principles. Furthermore, this application is intended to cover any deviations from this disclosure within known or customary practice in the field to which this invention pertains, and which fall within the scope of the appended claims.

Claims

1. A thermal interface material, comprising: Having a weight-average molecular weight (M) of less than 50,000 Daltons w Low molecular weight silicone oil; At least one with a value greater than 1.0m 2 Thermally conductive filler with a surface area of ​​ / g; and High molecular weight silicone oils, wherein the high molecular weight silicone oils comprise those having a weight-average molecular weight (M) of at least 60,000 Daltons. w Vinyl functional silicone oil.

2. The thermal interface material according to claim 1, wherein the thermal interface material has a viscosity greater than 1500 Pa·s.

3. The thermal interface material according to claim 1 further comprises a solvent having a boiling point between 60°C and 220°C and a viscosity between 0.2 cSt and 50 cSt.

4. The thermal interface material according to claim 3, wherein the thermal interface material has a viscosity between 150 Pa·s and 650 Pa·s.

5. The thermal interface material according to claim 1, wherein the thermal interface material comprises: 2% to 10% by weight of low molecular weight silicone oil; At least one thermally conductive filler, comprising 50% to 95% by weight; and 0.1% to 5% by weight of high molecular weight silicone oil; 0.1% to 5% by weight of solvent; 0.1% to 5% by weight of coupling agent; 0.1% to 1% by weight of crosslinking agent; 0.1% to 5% by weight of inhibitors; and 0.1% to 5% by weight of catalyst.

6. A thermal interface material, comprising: Having a weight-average molecular weight (M) of less than 50,000 Daltons w Low molecular weight silicone oil; First thermally conductive filler, second thermally conductive filler and third thermally conductive filler The first thermally conductive filler has a density of 0.1m. 2 / g to 1.0m 2 The second thermally conductive filler is a metal oxide with a surface area between 0.5 m² / g and 0.5 m² / g. 2 / g and 2.0m 2 The third thermally conductive filler has a surface area between 5.0 m² / g and 6.5 m² / g. 2 / g and 10.0m 2 Metal oxides with surface areas between / g; and High molecular weight silicone oils, wherein the high molecular weight silicone oils comprise those having a weight-average molecular weight (M) of at least 60,000 Daltons. w Vinyl functional silicone oils; and The solvent has a boiling point between 60°C and 220°C and a viscosity between 0.2 cSt and 50 cSt.

7. The thermal interface material according to claim 6, wherein the thermal interface material comprises: 2% to 10% by weight of low molecular weight silicone oil; 25% to 50% by weight of a first thermally conductive filler, wherein the first thermally conductive filler has a density of 0.1 m 2 / g to 1.0m 2 Surface area between / g; 25% to 50% by weight of a second thermally conductive filler, the second thermally conductive filler having a density of 0.5 m 2 / g and 2.0m 2 Surface area between / g; as well as 25% to 50% by weight of a third thermally conductive filler, said third thermally conductive filler having a thermal conductivity of 5.0 m 2 / g and 10.0m 2 Surface area between / g; 0.1% to 5% by weight of high molecular weight silicone oil; 0.1% to 5% by weight of solvent; 0.1% to 5% by weight of coupling agent; 0.1% to 1% by weight of crosslinking agent; 0.1% to 5% by weight of inhibitors; as well as 0.1% to 5% by weight of catalyst.

8. The thermal interface material according to claim 6, wherein the low molecular weight silicone oil comprises a vinyl-functionalized silicone oil, and the high molecular weight silicone oil is a vinyl silicone oil having a kinematic viscosity of 2,000,000 cSt.

9. The thermal interface material according to claim 6, wherein the thermal interface material has an exudation trace value between 1 mm and 5 mm and a flow rate between 20 g / min and 50 g / min.

10. An electronic component, comprising: Heat sink; Electronic chips; A thermal interface material positioned between the heat sink and the electronic chip, the thermal interface material comprising: Having a weight-average molecular weight (M) of less than 50,000 Daltons w Low molecular weight silicone oil; At least one with a value greater than 1.0m 2 Thermally conductive filler with a surface area of ​​ / g; and High molecular weight silicone oils, wherein the high molecular weight silicone oils comprise those having a weight-average molecular weight (M) of at least 60,000 Daltons. w Vinyl functional silicone oil.

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