CN107760278A - Composition as thermal interfacial material - Google Patents
Composition as thermal interfacial material Download PDFInfo
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- CN107760278A CN107760278A CN201610701277.6A CN201610701277A CN107760278A CN 107760278 A CN107760278 A CN 107760278A CN 201610701277 A CN201610701277 A CN 201610701277A CN 107760278 A CN107760278 A CN 107760278A
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- porous matrix
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- thermally conductive
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- OUJSWWHXKJQNMJ-UHFFFAOYSA-N 3,3,4,4-tetrafluoro-4-iodobut-1-ene Chemical compound FC(F)(I)C(F)(F)C=C OUJSWWHXKJQNMJ-UHFFFAOYSA-N 0.000 description 1
- GVCWGFZDSIWLMO-UHFFFAOYSA-N 4-bromo-3,3,4,4-tetrafluorobut-1-ene Chemical compound FC(F)(Br)C(F)(F)C=C GVCWGFZDSIWLMO-UHFFFAOYSA-N 0.000 description 1
- 229910052582 BN Inorganic materials 0.000 description 1
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- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 description 1
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- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
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- DLSMLZRPNPCXGY-UHFFFAOYSA-N tert-butylperoxy 2-ethylhexyl carbonate Chemical compound CCCCC(CC)COC(=O)OOOC(C)(C)C DLSMLZRPNPCXGY-UHFFFAOYSA-N 0.000 description 1
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
- C09K5/08—Materials not undergoing a change of physical state when used
- C09K5/14—Solid materials, e.g. powdery or granular
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Combustion & Propulsion (AREA)
- Thermal Sciences (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
The present invention relates to the composition as thermal interfacial material, it includes porous matrix and the packing material being filled in the hole of porous matrix, wherein described packing material includes about 20 80 weight % polymeric substrate and about 20 80 weight % heat conduction additive, and the weight % is the gross weight meter with packing material.
Description
Technical Field
The present invention relates to a composition for use as a thermal interface material, and more particularly, to a composition comprising a porous matrix and a filler material filled in pores of the porous matrix, the composition having improved thermal conductivity.
Background
In recent years, with the rapid development of the integration process of electronic devices, the integration degree of electronic devices is higher and higher, while the device size is smaller and smaller, and the requirement for heat dissipation is higher and higher. In order to meet the requirements, various heat dissipation methods are widely applied, such as fan heat dissipation, water-cooling auxiliary heat dissipation, heat pipe heat dissipation, and the like, and a certain heat dissipation effect is achieved, but because the contact interface between the heat sink and the electronic device is not flat, generally, the contact area between the heat sink and the electronic device is less than 10% of the area of the heat sink and an ideal contact interface is not provided, the effect of heat conduction from the electronic device to the heat sink is fundamentally greatly influenced, and therefore, it is necessary to add a thermal interface material with a higher thermal conductivity coefficient between the heat sink and the electronic device to increase the contact area between the interfaces.
Conventional thermal interface materials are composites of particles having a relatively high thermal conductivity, such as graphite, boron nitride, silicon oxide, aluminum oxide, silver, or other metals, dispersed in a polymeric material. The thermal conductivity of such materials depends to a large extent on the nature of the polymeric carrier. The composite material using grease and phase change material as carriers can be soaked with the surface of a heat source because of being in a liquid state when in use, so that the contact thermal resistance is small, and the contact thermal resistance of the composite material using silica gel and rubber as carriers is large. A common drawback of these materials is the relatively low thermal conductivity of the overall composite, about lW/mK, which is increasingly incompatible with the increased heat dissipation requirements of semiconductor integration, and increasing the content of thermally conductive particles in the polymer carrier to 60 wt% and above increases the thermal conductivity of the overall composite by bringing the particles into contact with one another as much as possible, e.g. the thermal conductivity of certain specific interface materials can reach 2-5W/mK, but increasing the content of thermally conductive particles in the polymer carrier to 85 wt% or above causes the polymer to lose the desired properties, e.g. grease, and thus wetting, and rubber, and thus flexibility, which all result in a significant decrease in the thermal interface material properties.
The ideal thermal interface material is placed between the heat sink and the heat source (i.e., the electronic device), and it is desirable that heat from the heat source be quickly conducted through the thermal interface material to the heat sink in a direction perpendicular to the heat source and the heat sink, thereby reducing the temperature of the heat source; meanwhile, the heat source and the radiator can be quickly diffused through a thermal interface material along the direction parallel to the heat source and the radiator, so that the phenomenon that a hot spot is generated due to local overheating to form a dead spot is avoided; therefore, the dual purposes of heat transfer and heat equalization are achieved, and the problems of performance reduction, instability, short service life and the like caused by insufficient heat dissipation, overhigh temperature and local heat accumulation of electronic devices are avoided. With the trend toward multi-functionality and miniaturization of electronic devices, the energy density generated when electronic devices are operated is higher and higher, and accordingly, it is desirable that both the vertical thermal conductivity (i.e., in the vertical direction of the heat source and the heat sink) and the parallel thermal conductivity (i.e., in the direction parallel to the heat source and the heat sink) of the thermal interface material be greater than or equal to 5W/mK.
Depending on the composition of the thermal interface material, the shape to be measured, the forming method, and the conditions applied in the forming method, the thermal conductivity of the thermal interface material may have a directional dependence, i.e., may exhibit isotropy or anisotropy. If the polymer-based thermal interface material is processed and molded by adopting a melt blending and hot pressing mode, and the heat-conducting filler is randomly dispersed in the polymer, the heat conductivity coefficient of the obtained thermal interface material is isotropic, but is low in all directions, about lW/mK, and cannot meet the requirement. If the polymer-based thermal interface material is processed and molded by adopting a mold injection molding mode, the thermal interface material is heated and then pressurized to flow into a mold, and then is cooled and molded, so that the thermal conductivity of the molded thermal interface material is anisotropic, the thermal conductivity in the material flow direction during thermal interface injection is generally about 2-8W/mK, which is 3-10 times of the thermal conductivity (about 0.6-2W/mK) perpendicular to the material flow direction, that is, the thermal conductivity in only one direction is more than 5W/mK, so that the requirements of heat conduction and uniform heat cannot be met simultaneously.
Accordingly, there is a need for a thermal interface material that provides thermal conductivity isotropically and has both a vertical thermal conductivity (i.e., in a direction perpendicular to the heat source and heat sink) and a parallel thermal conductivity (i.e., in a direction parallel to the heat source and heat sink) greater than or equal to 5W/mK.
Disclosure of Invention
The present invention provides a composition for use as a thermal interface material comprising:
(a) a porous matrix; and
(b) a filler material filled in pores of the porous matrix;
wherein the filler material comprises about 20-80 wt% of the polymeric base material and about 20-80 wt% of the thermally conductive additive, the wt% being based on the total weight of the filler material.
The present invention also provides a thermal interface component comprising the above composition for use as a thermal interface material.
The present invention also provides a method of making the above-described composition for use as a thermal interface material.
Drawings
FIG. 1 shows a cross-sectional view of one embodiment of a composition 10 of the present invention for use as a thermal interface material comprising: (a) a porous matrix 101 and (b) a filler material 102 filled in pores of the porous matrix, wherein the filler material 102 comprises a polymer base material 102-1 and a thermally conductive additive 102-2.
FIG. 2 shows a cross-sectional view of one embodiment of a thermal interface assembly 20 of the present invention comprising: a heat sink 201, a heat source 203, and a thermal interface device 202 disposed between the heat source and the heat sink, wherein the thermal interface device 202 comprises the composition of the present invention for use as a thermal interface material, the x-direction represents a direction parallel to the heat source and the heat sink, and the y-direction represents a perpendicular direction along the heat source and the heat sink.
Detailed Description
All publications, patent applications, patents, and other references mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if fully set forth herein, if not otherwise indicated.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.
All percentages, parts, ratios, etc., are by weight unless otherwise indicated.
As used in this specification, the term "prepared from" is synonymous with the term "comprising. As used in this specification, the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.
The conjunction "consisting of" does not include any unspecified elements, steps or components. If in the claims, such conjunctions would render the claims dependent upon the recited material, except for impurities normally associated therewith. When the phrase "consisting of" appears in a clause of the characterizing portion of the claims, rather than following the preamble, it is limited only to the elements listed in that clause; other elements are not excluded from the claim as a whole. The conjunction "consisting essentially of" is used to define a composition, method or apparatus that includes materials, steps, features, components or elements other than those literally discussed, provided that such additional materials, steps, features, components or elements do not materially affect the basic and novel characteristics of the claimed invention. The term "consisting essentially of" lies in a range intermediate between "comprising" and "consisting of.
The term "comprising" includes embodiments encompassed by the term "consisting essentially of and" consisting of. Similarly, the term "consisting essentially of includes embodiments encompassed by the term" consisting of.
When an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of an upper range limit or preferred value and a lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1-5" is recited, the disclosed range should be understood to include "1-4", "1-3", "1-2 and 4-5", "1-3 and 5", and so forth. Where a range of numerical values is recited in the specification, unless otherwise stated, the range is intended to include the endpoints of the range and all integers and fractions within the range.
When the term "about" is used to describe a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to.
Furthermore, unless expressly stated to the contrary, "or" refers to an inclusive "or" and not to an exclusive "or". For example, any of the following satisfies the condition of a "or" B: a is true (or present) and B is false (or not present), a is false (or not present) and B is true (or present), and both a and B are true (present).
Embodiments of the invention described in the summary of the invention section include any other embodiments described herein and can be combined in any manner, and the subject description in the embodiments relates not only to the compositions of the invention, but also to thermal interface assemblies comprising the compositions.
The present invention is described in detail below.
The composition for use as a thermal interface material of the present invention comprises: (a) a porous matrix and (b) a filler material filled in pores of the porous material, wherein the filler material comprises a polymer base material and a thermally conductive additive, and one embodiment of the composition for use as a thermal interface material of the present invention is illustrated in fig. 1.
(a) Porous matrix
In the present invention, the porous matrix (a) is a material having a one-, two-or three-dimensional spatial network structure formed by interconnected or closed pores; preferably, the material is a material with a spatial network structure formed by interconnected pores, i.e. a through-hole material.
The pore size, i.e., the diameter of the pores, of the porous substrate is about 50-3000 μm, or about 150-800 μm, or about 300-500 μm. The shape of the aperture may be any shape, such as circular, square, polygonal, or irregular. The Porosity of the porous matrix is at least 70%, or at least 80%, where Porosity (Porosity) is a physical quantity characterizing the pore portion of the porous matrix, defined as the ratio of the volume of the pores to the total volume of the porous matrix, expressed in percentages, between 0 and 100%. The porous matrix has a bulk density of about 0.1 to 1g/cm3The bulk density here means the weight per unit volume of the porous matrix in a natural state.
The porous matrix suitable for the composition of the present invention may be a metal foam made of a metal material selected from the group consisting of copper, aluminum, silver, gold, iron, steel, and alloys thereof, preferably a metal foam made of copper. In one embodiment of the invention, the porous matrix of the composition of the invention is a metal foam of through-pores.
The foamed metal suitable for the present invention may be prepared by any conventionally known method in the art, and specifically, the closed-cell foamed metal consisting of closed cells may be obtained by a foaming process such as a melt foaming method, a direct blowing gas foaming method, a metal powder and blowing agent mixture densification foaming method; the through-hole metal foam composed of interconnected pores can be obtained by the processes of seepage casting, deposition, powder loose sintering and pore-forming agent addition, for example, a porous prefabricated member is obtained firstly, the prefabricated member can be a sintered body of salt (NaC1) or porous plastic, and then the porous prefabricated member is utilized to carry out the processes of seepage, deposition, sintering and the like, so as to obtain the through-hole metal foam.
The porous matrix suitable for use in the composition of the present invention may also be a porous matrix made from a non-metallic material such as carbon foam, ceramic foam, or a foamed polymer made from a material selected from the group consisting of silicone, polyurethane, polyethylene, rubber, ethylene vinyl acetate, and mixtures thereof. Wherein the ceramic foam suitable for the present invention may be foamed alumina, foamed zirconia, foamed silicon carbide, or foamed silicon nitride. In one embodiment of the invention, the porous matrix of the composition of the invention is a foamed polysiloxane.
Carbon foams suitable for the present invention can be prepared by any method conventionally known in the art, such as organic precursor pressure foaming or templating. The ceramic foams suitable for the present invention may be prepared by any conventional method known in the art, such as foaming, sol-gel, addition of pore formers, or impregnation with organic precursors. Foamed polymers suitable for the present invention can be made by any method conventionally known in the art, such as a foaming process, wherein the blowing agent can be a chemical blowing agent, gas, or water, for example, in the preparation of silicone cellular materials, a fluid, such as carbon dioxide, nitrogen, or chlorofluorocarbon, can first be immersed under pressure in blocks of a silicone block copolymer for a period of time to form a fluid-saturated silicone block copolymer, the fluid being dissolved in the silicone block copolymer, nucleating and growing to form a silicone cellular material when the pressure is removed, the fluid used being in gaseous, liquid or supercritical form.
Porous substrates suitable for use in the present invention are commercially available, for example, copper foam products available from Shanghai Zhongweixin New materials, Inc. under the designation Cu-10, copper foam products available from Kunshan Jiayi Sheng electronics New materials, Inc. under the designation JYS01, or aluminum foam products available from Shanghai Zhonghui aluminum foam, carbon foam available from Kyuwa carbon Kogyo, Inc., silicon carbide foam and aluminum oxide foam available from Baodingning Xin New materials, Inc., silicon carbide foam available from Zhongyuan ceramic, Inc., or ethylene vinyl acetate foam available from Changzhou Dend plastics factories.
Filling material (b)
In the present invention, the composition for use as a thermal interface material further comprises a filler material (b) filled in the pores of the porous matrix, the filler material comprising about 20 to 80% by weight of the polymer base material and about 20 to 80% by weight of the thermally conductive additive, or about 25 to 75% by weight of the polymer base material and about 25 to 75% by weight of the thermally conductive additive, the% by weight being based on the total weight of the filler material.
The polymeric substrate used in the composition of the present invention may be selected from the group consisting of ethylene methacrylic acid copolymers, ethylene vinyl acetate copolymers, ethylene acrylic acid copolymer elastomers, fluoroelastomers, and mixtures thereof.
In one embodiment of the invention, the polymeric substrate used in the composition of the invention is an ethylene methacrylic acid copolymer.
In another embodiment of the invention, the polymeric substrate used in the composition of the invention is an ethylene vinyl acetate copolymer.
In yet another embodiment of the present invention, the polymeric substrate of the composition used in the present invention is a mixture of an ethylene acrylic acid copolymer and a fluoroelastomer comprising about 10 to 40 weight percent ethylene acrylic acid copolymer and about 60 to 90 weight percent fluoroelastomer, the weight percent being based on the total weight of the mixture of ethylene acrylic acid copolymer and fluoroelastomer. The fluoroelastomers contain at least about 53 weight percent fluorine, specifically, fluoroelastomers suitable for the present invention contain the following copolymerized units: vinylidene fluoride and at least one other fluoromonomer selected from hexafluoropropylene, tetrafluoroethylene, 4-bromo-3, 3,4, 4-tetrafluorobutene-1, 4-iodo-3, 3,4, 4-tetrafluorobutene-1, perfluoro (methyl vinyl) ether, 1,3,3, 3-pentafluoropropene, or mixtures thereof.
Polymeric substrates suitable for the compositions of the present invention are commercially available, for example, from dupont corporation (e.i. du pont nemours and company, inc.) under the designation "dupont" hereinafter40W ethylene vinyl acetate copolymer of the brand number599 ethylene methacrylic acid copolymer having the designationDP ethylene acrylic acid copolymer elastomer, or trade designationThe fluoroelastomers of GF200s, ethylene vinyl acetate copolymer available from Sumitomo chemical Co., Ltd under the brand number RB-11, or from Taiwan Polymer Chemicals Ltd under the brand number Taiwan Polymer653-04 ethylene vinyl acetate copolymer.
Optionally, the filling material may further comprise other additives, such as a cross-linking agent and an antioxidant. In one embodiment of the invention, the filler material of the composition of the invention further comprises from about 0.1 to about 5 weight percent of a crosslinking agent, the weight percent being based on the weight of the polymeric matrix material in the filler material. Wherein the crosslinking agent may be 1, 1-di (t-butylperoxy) -3,3, 5-trimethylcyclohexane and/or t-butyl peroxy-2-ethylhexyl carbonate.
The thermally conductive additive suitable for use in the composition of the present invention may be selected from the group consisting of expanded graphite, graphite nanoplatelets, carbon fibers, metal particles, and mixtures thereof, preferably expanded graphite, graphite nanoplatelets, and mixtures thereof.
In one embodiment of the present invention, the thermally conductive additive for the composition of the present invention is expanded graphite having a length of 200-500 μm, a width of 50-800 μm, and a bulk density of not more than 0.2g/cm3. The expanded graphite may be made from expandable graphite, for example, by placing the expandable graphite in air or inert gasHeating to about 400-1000 ℃ in gas, and then preserving the temperature for about 5-10 minutes. Suitable expandable graphite materials for use therein are sheet-like structures having an in-sheet transverse dimension of from about 50 to about 800 μm and a thickness of from about 0.5 to about 30 μm.
In another embodiment of the invention, the thermally conductive additive for the composition of the invention is a graphite nanoplatelets having a platelet-like structure with a thickness of from about 1 nm to about 30nm, or from about 10 nm to about 25nm, and an in-sheet transverse dimension of from about 1 μm to about 15 μm. The in-sheet transverse dimension as referred to herein is the largest dimension along the surface of the sheet of expandable graphite or the surface of the sheet of graphite nanoplatelets.
The thermally conductive additives used in the composition of the present invention are commercially available, such as silver or copper particles from Ningbo Guangbo nano New Material Co., Ltd, 325 mesh size chopped carbon fiber powder from Nanjing Yidao composite Co., Ltd, or graphite nanoplatelets from Nanjing GmbH nanotechnology Co., Ltd under the brand name JCGNP 10-5. Expandable graphite for preparing expanded graphite for use as a heat conductive additive is also commercially available, for example, expandable graphite available from qinghai and graphite ltd, or low sulfur treated expandable graphite available from seikon carbon products ltd having a size of 100 mesh, 200 mesh, or 50 mesh.
Preparation of compositions for use as thermal interface materials
There is no particular limitation on the method for preparing the above-described composition for use as a thermal interface material in the present invention, and it may be any conventionally known method in the art. For example, the method may comprise the steps of: (i) providing a porous matrix, a polymeric substrate, and a thermally conductive additive; (ii) melting and blending the polymer base material and the heat conduction additive, and then hot-pressing the mixture into a flaky filling material; (iii) the sheet-like filler material is placed on the porous substrate, and then hot-pressed so that the filler material is pressed into the pores of the porous substrate, to obtain the composition for a thermal interface material of the present invention.
In one embodiment of the present invention, a method of making a composition of the present invention for use as a thermal interface material comprises the steps of:
(i) providing a porous matrix, a polymeric substrate, and a thermally conductive additive;
(ii) melting and blending the polymer base material and the heat conduction additive, and then hot-pressing the mixture into a flaky filling material; and
(iii) placing the sheet-like filler material on the porous substrate, and hot pressing to press the filler material
Into the pores of the porous matrix to obtain a composition for use as a thermal interface material;
wherein the filler material comprises about 20-80 wt% of the polymeric base material and about 20-80 wt% of the thermally conductive additive, the wt% being based on the total weight of the filler material.
The present invention also provides a thermal interface assembly comprising a heat source, a heat sink, and a thermal interface device disposed between the heat source and the heat sink, wherein the thermal interface device comprises the above-described composition for use as a thermal interface material. FIG. 2 shows a cross-sectional view of one embodiment of a thermal interface assembly of the present invention comprising: a heat sink 201, a heat source 203, and a thermal interface device 202 disposed between the heat source and the heat sink, wherein the thermal interface device 202 comprises the composition of the present invention for use as a thermal interface material, the x-direction represents a direction parallel to the heat source and the heat sink, and the y-direction represents a perpendicular direction along the heat source and the heat sink. The heat source of the thermal interface assembly may be a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), a processor Integrated Heat Sink (IHS), a power module, or other heat generating electronic device.
As previously mentioned, it is desirable to have a thermal interface material with an isotropic and sufficiently high thermal conductivity, i.e., a thermal interface material with a vertical thermal conductivity (i.e., in the vertical direction along the heat source and heat sink) and a parallel thermal conductivity (i.e., in the direction parallel to the heat source and heat sink) that are greater than or equal to 5W/mK. In the present invention, a desired composition can be prepared by filling the pores of the porous matrix with a filler material comprising a polymer base material and a thermally conductive filler. The composition of the present invention not only has a vertical thermal conductivity and a parallel thermal conductivity greater than 5W/mK, but also exhibits an increase in vertical thermal conductivity of about 50% or more, preferably about 100% or more, more preferably about 150% or more, as compared to a composition comprising the same polymeric base material and thermally conductive filler, but not comprising the porous matrix.
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. Accordingly, the following examples are illustrative only and are not intended to limit the disclosure in any way.
Examples
The abbreviation "E" stands for "examples" and "CE" for "comparative examples", the numbers following which indicate in which example the composition was prepared. Examples and comparative examples were both prepared and tested in a similar manner.
Material
Porous matrix (Cu foam): the copper foam of the through-holes has the size of 5cm multiplied by 1mm, the diameter of the pores is about 300-500 mu m, the porosity is about 80%, the diameter of the single copper wires constituting the pores is about 100-200 mu m, and the mark Cu-10 is purchased from Shanghai Zhongwei New type materials Co.
Polymer base-1 (P-1): ethylene methacrylic acid copolymer, by mark599 from dupont.
Polymer substrate-2 (P-2): ethylene vinyl acetate copolymer, by mark40W was obtained from DuPont.
Polymer base material-3 (P-3): about 20 weightA blend of an ethylene acrylic acid copolymer elastomer in an amount% and about 80 wt.% of a fluoroelastomer, the wt.% being based on the total weight of the mixture of ethylene acrylic acid copolymer elastomer and fluoroelastomer, wherein the ethylene acrylic acid copolymer elastomer is under the designationDP is available from DuPont under the trademark "fluoroelastomersGF200s was obtained from dupont.
A crosslinking agent: tert-butyl peroxy-2-ethylhexyl carbonate, CAS No. 3006-82-4, available from Chemicals, Inc., national pharmaceutical group.
Heat conductive additive-1 (T-1): expanded graphite, a cellular structure of vermicular shape, a length of about 80 to 5000 μm, a width of 75 μm, and a bulk density of 0.18g/cm3The heat-conducting additive is prepared from low-sulfur expandable graphite which is purchased from Exxon carbon products Co., Ltd, has the specification of 200 meshes and the transverse dimension of a sheet being about 75 mu m, the purchased expandable graphite is placed in a muffle furnace, heated to 400 ℃ in air atmosphere, kept for 5 minutes until the volume is not changed any more, and then cooled to room temperature, and the expanded graphite of the heat-conducting additive-1 is obtained.
Heat conductive additive-2 (T-2): expanded graphite, a cellular structure of vermicular shape, a length of about 80 to 5000 μm, a width of 150 μm, and a bulk density of 0.1g/cm3The heat-conducting additive is prepared from low-sulfur expandable graphite which is purchased from Exxon carbon products Co., Ltd, has the specification of 100 meshes and the transverse dimension of a sheet being about 150 mu m, the purchased expandable graphite is placed in a muffle furnace, heated to 400 ℃ in air atmosphere, kept for 5 minutes until the volume is not changed any more, and then cooled to room temperature, and the expanded graphite of the heat-conducting additive-2 is obtained.
Heat conductive additive-3 (T-3): expanded graphite, a cellular structure of vermicular shape, a length of about 80 to 5000 μm, a width of 300 μm, and a bulk density of 0.04g/cm3From Aikesen carbon products of the commercial SecurityThe low-sulfur expandable graphite with the specification of 50 meshes and the transverse dimension of a sheet being about 300 mu m is prepared by putting the purchased expandable graphite into a muffle furnace, heating to 400 ℃ in air atmosphere, keeping for 5 minutes until the volume is not changed, and then cooling to room temperature to obtain the expanded graphite of the heat-conducting additive-3.
Heat conductive additive-4 (T-4): graphite nanoplatelets having an internal lateral dimension of about 5 μm and a thickness of about 15nm are available from Nanjing Chikung nanotechnology Co., Ltd under the trade designation JCGNP 10-5.
Heat conductive additive-5 (T-5): a mixture comprising about 60 wt% of a thermally conductive additive-3 and about 40 wt% of a tin-bismuth (SnBi) alloy powder, wherein the SnBi alloy powder is available from huayuan technologies ltd, huizhou and has a D50 size of about 25 μm.
Preparation of compositions E1-E12 and CE1-CE12
1. Preparation of compositions of CE2-CE5, CE7, CE8, CE10 and CE12
The polymer base material, the crosslinking agent and the heat conductive filler were melt-mixed in an internal Mixer (Mixer350E, plastic-core Lab-Station, Brabender GmbH & co. kg) at about 40 ℃ in the proportions set forth in tables 1 to 3, and then the resulting mixture was hot-pressed into a sheet of 1mm thickness by a flat hot press (GT-7014-a, GOTECH testing Machines Inc) at about 90 ℃ in an air atmosphere and cut into 5cm × 5cm in planar dimensions to obtain a sheet-like composition of 5cm × 5cm × 1mm in size.
2. Preparation of compositions of CE1, CE6, CE9, CE11 and E1-E12
The polymer base material, the crosslinking agent and the optional thermally conductive filler were melt-mixed in an internal Mixer (Mixer350E, plastic-core Lab-Station, Brabender GmbH & co. kg) in the proportions set forth in tables 1 to 3 at about 40 ℃ to obtain a filled composition, and the resulting filled composition was then hot-pressed into sheets of about 1mm thickness by a flat hot press (GT-7014-a, gotechtestingmachines Inc) at about 90 ℃ in an air atmosphere and cut into 5cm × 5cm in planar dimensions to obtain a sheet-like filled material of 5cm × 5cm × 1mm in dimensions. Placing the prepared sheet-shaped filling material with the size of 5cm × 5cm × 1mm on the copper foam of the through hole with the size of 5cm × 5cm × 1mm so that the 5cm × 5cm plane of the sheet-shaped filling material completely covers the 5cm × 5cm plane of the copper foam, and then heating the sheet-shaped filling material to 100 ℃ in an air atmosphere by using a flat hot press (GT-7014-a), and hot-pressing for 10 minutes by using a pressure of 0.1MP so that the sheet-shaped filling material is melted and completely pressed into the pores of the copper foam; then raising the temperature to 150 ℃, after hot pressing is continued for 15 minutes under the pressure of 0.1MPa, taking out from the hot press and naturally cooling to room temperature to obtain the corresponding composition.
Test method
The composition obtained from E1-12 and CE1-CE12 was cut into disc-shaped sheets with a diameter of 2.5mm and a thickness of 1mm, graphite powder was uniformly sprayed on the upper and lower surfaces, and the graphite powder was measured by a laser thermal conductivity meter (LFA 447,GmbH) to measure the in-plane thermal conductivity λ of the sample∥(W/mK), i.e., the parallel to thermal conductivity (i.e., in a direction parallel to the heat source and heat sink) when used in a thermal interface assembly.
The composition obtained from E1-12 and CE1-CE12 was cut into disc-shaped sheets with a diameter of 6mm and a thickness of 1mm, graphite powder was uniformly sprayed on the upper and lower surfaces, and the graphite powder was measured according to ASTM E1461 using a laser thermal conductivity meter (LFA 447,GmbH) to measure the through-plane heat conductivity coefficient λ of the sample⊥(W/mK), i.e., the vertical thermal conductivity (i.e., in a direction perpendicular to the heat source and heat sink) when used in a thermal interface assembly.
Improvement of vertical thermal conductivity (delta lambda)⊥%) is calculated by the following formula:
Δλ⊥％＝[(λ⊥n-λ⊥0)/λ⊥0]×100
wherein λ⊥0Is the lambda value of the reference example; lambda [ alpha ]⊥nλ as an example for comparison⊥The value is obtained.
TABLE 1
“a"show CE2 as a reference example for improved calculations for E1-E3; "b"reference example showing that CE3 was used for improved calculation of E4 and E5; "c"indicating CE4 as a reference example for improved calculation of E6; "d"reference example showing that CE5 was used for improved calculation of E7 and E8; "e"indicates that the filler material also contains 2 wt% of the cross-linking agent tert-butyl peroxy-2-ethylhexyl carbonate, based on the weight of the polymer matrix in the filler material.
From the results of Table 1, the following description is evident.
Comparison between the thermal conductivity data for E2 and CE2 shows that: the vertical thermal conductivity of the composition of E2, prepared by filling the pores of the porous matrix with a filler material comprising the polymer matrix P-1 (ethylene methacrylic acid copolymer) and the thermally conductive additive T-1 (expanded graphite), increased significantly by about 474% compared to the vertical thermal conductivity of the composition of CE2 comprising the same parts by weight of P-1 and T-1.
Comparison between the thermal conductivity data for E1 and CE2 shows that: the composition of E1 incorporated a porous matrix, and although the content of T-1 therein was only 30% by weight, the vertical thermal conductivity of the composition of E1 was not reduced but increased by about 179% as compared with the composition of CE2 containing 50% by weight of T-1 but not containing a porous matrix.
Comparison between the thermal conductivity data for E3 and CE2 shows that: the composition of E1, incorporating a porous matrix and the T-1 content increased to 70 wt%, significantly increased the vertical thermal conductivity of the E3 composition by about 553% compared to the composition of CE2, which contained 50 wt% of T-1 but no porous matrix.
Similarly, when the thermally conductive additive is changed to an expanded graphite of other dimensions, such as T-2 or T-3, or to a graphite nanoplatelets T-4, the vertical thermal conductivity of the corresponding composition is unexpectedly increased.
In particular, a comparison between the thermal conductivity data for E5 and CE3 shows that: the vertical thermal conductivity of the composition of E5 prepared by filling the pores of the porous matrix with the filler material comprising P-1 and T-2 was significantly increased by about 472% compared to that of the composition of CE3 comprising the same parts by weight of P-1 and T-2.
Comparison between the thermal conductivity data for E4 and CE3 shows that: the composition of E4 incorporated a porous matrix, and although the content of T-2 therein was only 30% by weight, the vertical thermal conductivity of the composition of E4 was not reduced but increased by about 180% as compared with the composition of CE3 containing T-2 in an amount of 50% by weight but not containing a porous matrix.
Comparison between the thermal conductivity data for E6 and CE4 shows that: the composition of E6 incorporated a porous matrix, and although the content of T-3 therein was only 30% by weight, the vertical thermal conductivity of the composition of E6 was not reduced but increased by about 223% as compared with the composition of CE4 containing 50% by weight of T-3 but not containing a porous matrix.
Comparison between the thermal conductivity data for E8 and CE5 shows that: the vertical thermal conductivity of the composition of E8 prepared by filling the pores of the porous matrix with the filler material comprising P-1 and T-4 was significantly increased by about 531% as compared to that of the composition of CE5 comprising the same parts by weight of P-1 and T-4.
Comparison between the thermal conductivity data for E7 and CE5 shows that: the composition of E7 incorporated a porous matrix, and although the content of T-4 therein was only 30% by weight, the vertical thermal conductivity of the composition of E7 was not reduced but increased by about 323% as compared with the composition of CE3 containing T-4 in an amount of 50% by weight but not containing a porous matrix.
The above results show that the composition prepared by filling the pores of the porous matrix with the filler material comprising the polymer base material and the thermally conductive additive has an increase in vertical thermal conductivity of at least 470% or more, as compared with the composition comprising the same components of the filler material comprising the polymer base material and the thermally conductive additive, but not comprising the porous matrix; even when the content of the heat conductive additive therein is reduced to 30% by weight, the vertical thermal conductivity thereof is unexpectedly increased by at least 179% or more.
Comparison of the thermal conductivity data for E1-E8 and CE1 also shows that: the composition of E1-E8, which was prepared by filling the pores of the porous matrix with a filler material comprising a polymer matrix P-1 and a thermally conductive additive, also had a significant increase in the vertical thermal conductivity from 3.4W/mK to 5.3-14.3W/mK and a significant increase in the parallel thermal conductivity from 4.6W/mK to 5.4-12.5W/mK, compared to the composition of CE1, which comprises only P-1 and the porous matrix.
The thermal conductivity data of E1-E8 also indicate that by filling the pores of the porous matrix with a filler material comprising the polymeric substrate P-1 and a thermally conductive additive, the compositions of the present invention were found to have vertical thermal conductivities (i.e., in a direction perpendicular to the heat source and heat sink) of greater than 5W/mK; at the same time, the parallel thermal conductivity of the composition of the present invention can be maintained at 5W/mK or more, and thus a composition having isotropic thermal conductivity and sufficiently high enough to be used as a thermal interface material is obtained.
In one embodiment of the present invention, the composition for use as a thermal interface material comprises:
(a) a porous matrix; and
(b) a filler material filled in pores of the porous matrix;
wherein,
the porous substrate is a metal foam made of copper;
the filler material comprises about 25-75 wt% of ethylene methacrylic acid copolymer and about 25-75 wt% of a thermally conductive additive, the wt% being based on the total weight of the filler material; and
the thermally conductive additive is selected from the group consisting of expanded graphite, graphite nanoplatelets, and mixtures thereof.
TABLE 2
“a"indicating CE7 as a reference example for improved calculation of E9; "b"reference example indicating that CE8 was used for improved calculation of E10; "c"indicating CE10 as a reference example for improved calculation of E11; "d"indicates that the filler material also contains 2 wt% of the cross-linking agent tert-butyl peroxy-2-ethylhexyl carbonate, based on the weight of the polymer matrix in the filler material.
From the results of Table 2, the following description is evident.
Comparison of thermal conductivity data between E9 and CE7, E10 and CE8, E11 and CE10 shows: the vertical thermal conductivity of the composition of E9-E11, prepared by filling the pores of a porous matrix with a filler material comprising a polymeric matrix P-2 (ethylene vinyl acetate copolymer) and a thermally conductive additive T-3 (expanded graphite), unexpectedly increased by about 193% to 1000% over the vertical thermal conductivity of the corresponding composition comprising the same parts by weight of P-2 and T-3.
Comparison of the thermal conductivity data for E9-E11 and CE6 also shows that: the composition of E9-E11, which was prepared by filling the pores of the porous matrix with the filler material comprising P-2 and T-3, also had a significant increase in the vertical thermal conductivity from 2.8W/mK to 13.5-16.1W/mK and a significant increase in the parallel thermal conductivity from 3.6W/mK to 10.8-15.2W/mK, as compared with the composition of CE6, which comprises only P-2 and the porous matrix. .
The thermal conductivity data of E9-E11 also indicate that by filling the pores of the porous matrix with a filler material comprising P-2 and T-3, the compositions of the present invention are found to have vertical thermal conductivities of greater than 10W/mK or more; at the same time, the parallel thermal conductivity of the composition of the present invention can be maintained at 10W/mK or more, and thus a composition having isotropic thermal conductivity and sufficiently high enough to be used as a thermal interface material is obtained.
Furthermore, a comparison of the thermal conductivity data for CE9 and E10 also shows that: when the thermal conductive additive T-3 was changed to T-5, i.e., a mixture comprising about 60 wt% of T-3 and about 40 wt% of tin-bismuth (SnBi) alloy powder, the vertical thermal conductivity of the corresponding composition was reduced to 4.6W/mK.
In one embodiment of the present invention, the composition for use as a thermal interface material comprises:
(a) a porous matrix; and
(b) a filler material filled in pores of the porous matrix;
wherein the porous substrate is a metal foam made of copper;
the filler material comprises about 25-75 wt% of ethylene vinyl acetate copolymer and about 25-75 wt% of expanded graphite, the wt% being based on the total weight of the filler material.
TABLE 3
“a"indicating CE12 as a reference example for improved calculation of E12; "b"indicates that the filler material also contains 2% by weightThe weight% being based on the weight of the polymer base material in the filler material.
From the results of Table 3, the following description is evident
Comparison between the thermal conductivity data for E12 and CE12 shows that: the composition of E1, prepared by filling the pores of the porous matrix with a filler material comprising a polymeric substrate P-3 and a thermally conductive additive T-3 (in an amount of 50 wt%), exhibited no decrease in the vertical thermal conductivity of the composition of E12, but unexpectedly increased by about 184% compared to the composition of CE12, which comprises a thermally conductive additive T-3 in an amount of 30 wt% but does not comprise a porous matrix.
Comparison between the thermal conductivity data for E12 and CE11 also shows that: the composition of E12 prepared by filling the pores of the porous matrix with the filler material comprising P-3 and T-3 also had a significant increase in the vertical thermal conductivity from 4.4W/mK to 7.1W/mK and a significant increase in the parallel thermal conductivity from 4.8W/mK to 10.2W/mK, as compared to the composition of CE11 comprising only P-3 and the porous matrix, i.e., the composition of the invention was found to have both vertical and parallel thermal conductivities greater than 7W/mK, thereby achieving the desired isotropic and sufficiently high thermal conductivity for use as a thermal interface material.
In one embodiment of the present invention, the composition for use as a thermal interface material comprises:
(a) a porous matrix; and
(b) a filler material filled in pores of the porous matrix;
wherein the porous substrate is a metal foam made of copper;
the filler material comprises about 25-75 wt% of a polymeric matrix and about 25-75 wt% of expanded graphite, the wt% being based on the total weight of the filler material;
and the polymeric substrate comprises from about 10 to 40 weight percent of the ethylene acrylic acid copolymer and from about 60 to 90 weight percent of the fluoroelastomer, the weight percent being based on the total weight of the mixture of ethylene acrylic acid copolymer and fluoroelastomer.
While the invention has been illustrated and described in typical embodiments, it is not intended to be limited to the details shown, since various modifications and substitutions are possible without departing in any way from the spirit of the present invention. Thus, modifications and equivalents of the invention herein disclosed may occur to persons skilled in the art using no more than routine experimentation, and all such modifications and equivalents are believed to be within the spirit and scope of the invention as defined by the following claims.
Claims (10)
1. A composition for use as a thermal interface material comprising:
(a) a porous matrix; and
(b) a filler material filled in pores of the porous matrix;
wherein:
the filler material comprises 20-80 wt% of a polymeric base material and 20-80 wt% of a thermally conductive additive, the wt% being based on the total weight of the filler material.
2. The composition for use as a thermal interface material according to claim 1, wherein said porous matrix is a foamed metal made of a metal material selected from the group consisting of copper, aluminum, silver, gold, iron, steel, and alloys thereof.
3. A composition for use as a thermal interface material according to claim 1, wherein said porous matrix has a porosity of at least 70% and pores with a diameter of 50-3000 μm.
4. A composition for use as a thermal interface material according to claim 1, wherein said polymeric substrate is selected from the group consisting of ethylene methacrylic acid copolymers, ethylene vinyl acetate copolymers, ethylene acrylic acid copolymers, fluoroelastomers, and mixtures thereof.
5. A composition for use as a thermal interface material as claimed in claim 1, wherein the thermally conductive additive is selected from the group consisting of expanded graphite, graphite nanoplatelets, carbon fibers, metal particles, and mixtures thereof.
6. The composition for use as a thermal interface material of claim 1, wherein the heat-conducting additive is expanded graphite, and the expanded graphite has a length of 200-500 μm, a width of 50-800 μm, and a bulk density of 0.2g/cm or less3。
7. A composition for use as a thermal interface material according to claim 1, wherein said thermally conductive additive is a graphite nanoplatelet having a thickness of from 1 to 30nm and an in-sheet lateral dimension of from 1 to 10 μm.
8. The composition for use as a thermal interface material according to claim 1, which has a vertical thermal conductivity and a parallel thermal conductivity of 5.0W/mK or more.
9. A thermal interface assembly comprising a heat source, a heat sink, and a thermal interface device disposed between the heat source and the heat sink, the thermal interface device comprising the composition for use as a thermal interface material of any one of claims 1-8.
10. A method of making a composition for use as a thermal interface material as claimed in any one of claims 1 to 8, comprising the steps of:
(i) providing a porous matrix, a polymeric substrate, and a thermally conductive additive;
(ii) after melting and blending the polymer base material and the heat conduction additive, hot-pressing the mixture into a flaky filling material; and
(iii) placing a flaky filling material on a porous matrix, and then hot-pressing to press the filling material into pores of the porous matrix to obtain a composition used as a thermal interface material;
wherein:
the filler material comprises 20-80 wt% of a polymeric base material and 20-80 wt% of a thermally conductive additive, the wt% being based on the total weight of the filler material.
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108548156A (en) * | 2018-05-11 | 2018-09-18 | 华域视觉科技(上海)有限公司 | Novel lightweight LED car lamp cooling system |
| CN108948724A (en) * | 2018-08-22 | 2018-12-07 | 清华大学 | A kind of preparation method of high mechanical loss factor thermoplastic urethane foam |
| CN111196878A (en) * | 2018-11-20 | 2020-05-26 | 通用汽车环球科技运作有限责任公司 | Cured in place lightweight thermal interface |
| CN111574967A (en) * | 2020-05-06 | 2020-08-25 | 苏州通富超威半导体有限公司 | Heat dissipation material, chip packaging assembly applying heat dissipation material and preparation method |
| WO2021081799A1 (en) * | 2019-10-29 | 2021-05-06 | 追信数字科技有限公司 | Method of manufacturing honeycomb solid-liquid composite heat dissipation material for cpu heat dissipation |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2693771Y (en) * | 2003-12-13 | 2005-04-20 | 鸿富锦精密工业（深圳）有限公司 | Thermal interfacial material |
| JP2005347500A (en) * | 2004-06-03 | 2005-12-15 | Fuji Electric Holdings Co Ltd | Heatsink member of electronic part |
| CN101906288A (en) * | 2009-06-02 | 2010-12-08 | 清华大学 | Thermal interface material, electronic device with same and preparation method |
| CN102917574A (en) * | 2012-10-24 | 2013-02-06 | 华为技术有限公司 | Heat-conducting pad, method for manufacturing heat-conducting pad, radiating device and electronic device |
| CN103122241A (en) * | 2013-03-05 | 2013-05-29 | 先进储能材料国家工程研究中心有限责任公司 | High thermal conductive composite material and preparation method thereof |
| CN103589134A (en) * | 2013-11-12 | 2014-02-19 | 四川金路集团股份有限公司 | Foam type thermal interface material with high thermal conductivity and preparation method of foam type thermal interface material |
| US20140110049A1 (en) * | 2012-10-19 | 2014-04-24 | The Hong Kong University Of Science And Technology | Three Dimensional Interconnected Porous Graphene-Based Thermal Interface Materials |
| CN103965839A (en) * | 2013-02-05 | 2014-08-06 | 中国科学院上海微系统与信息技术研究所 | Preparation method for flexible heat-conducting pad |
-
2016
- 2016-08-22 CN CN201610701277.6A patent/CN107760278A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2693771Y (en) * | 2003-12-13 | 2005-04-20 | 鸿富锦精密工业（深圳）有限公司 | Thermal interfacial material |
| JP2005347500A (en) * | 2004-06-03 | 2005-12-15 | Fuji Electric Holdings Co Ltd | Heatsink member of electronic part |
| CN101906288A (en) * | 2009-06-02 | 2010-12-08 | 清华大学 | Thermal interface material, electronic device with same and preparation method |
| US20140110049A1 (en) * | 2012-10-19 | 2014-04-24 | The Hong Kong University Of Science And Technology | Three Dimensional Interconnected Porous Graphene-Based Thermal Interface Materials |
| CN102917574A (en) * | 2012-10-24 | 2013-02-06 | 华为技术有限公司 | Heat-conducting pad, method for manufacturing heat-conducting pad, radiating device and electronic device |
| CN103965839A (en) * | 2013-02-05 | 2014-08-06 | 中国科学院上海微系统与信息技术研究所 | Preparation method for flexible heat-conducting pad |
| CN103122241A (en) * | 2013-03-05 | 2013-05-29 | 先进储能材料国家工程研究中心有限责任公司 | High thermal conductive composite material and preparation method thereof |
| CN103589134A (en) * | 2013-11-12 | 2014-02-19 | 四川金路集团股份有限公司 | Foam type thermal interface material with high thermal conductivity and preparation method of foam type thermal interface material |
Non-Patent Citations (2)
| Title |
|---|
| 仝兴存: "《电子封装热管理先进材料》", 30 April 2016, 国防工业出版社 * |
| 周文英等: "《导热高分子材料》", 30 April 2014, 国防工业出版社 * |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108548156A (en) * | 2018-05-11 | 2018-09-18 | 华域视觉科技(上海)有限公司 | Novel lightweight LED car lamp cooling system |
| CN108948724A (en) * | 2018-08-22 | 2018-12-07 | 清华大学 | A kind of preparation method of high mechanical loss factor thermoplastic urethane foam |
| CN111196878A (en) * | 2018-11-20 | 2020-05-26 | 通用汽车环球科技运作有限责任公司 | Cured in place lightweight thermal interface |
| US11398653B2 (en) | 2018-11-20 | 2022-07-26 | GM Global Technology Operations LLC | Cure-in-place lightweight thermally-conductive interface |
| CN111196878B (en) * | 2018-11-20 | 2022-11-29 | 通用汽车环球科技运作有限责任公司 | Cured in place lightweight thermal interface |
| WO2021081799A1 (en) * | 2019-10-29 | 2021-05-06 | 追信数字科技有限公司 | Method of manufacturing honeycomb solid-liquid composite heat dissipation material for cpu heat dissipation |
| CN111574967A (en) * | 2020-05-06 | 2020-08-25 | 苏州通富超威半导体有限公司 | Heat dissipation material, chip packaging assembly applying heat dissipation material and preparation method |
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