WO2021206098A1 - Copper paste, wick formation method and heat pipe - Google Patents

Copper paste, wick formation method and heat pipe Download PDF

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Publication number
WO2021206098A1
WO2021206098A1 PCT/JP2021/014659 JP2021014659W WO2021206098A1 WO 2021206098 A1 WO2021206098 A1 WO 2021206098A1 JP 2021014659 W JP2021014659 W JP 2021014659W WO 2021206098 A1 WO2021206098 A1 WO 2021206098A1
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Prior art keywords
copper
wick
diameter
copper particles
mass
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PCT/JP2021/014659
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French (fr)
Japanese (ja)
Inventor
偉夫 中子
芳則 江尻
大 石川
美智子 名取
征央 根岸
Original Assignee
昭和電工マテリアルズ株式会社
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Application filed by 昭和電工マテリアルズ株式会社 filed Critical 昭和電工マテリアルズ株式会社
Priority to CN202180026703.XA priority Critical patent/CN115397584A/en
Priority to JP2022514092A priority patent/JPWO2021206098A1/ja
Publication of WO2021206098A1 publication Critical patent/WO2021206098A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/02—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite layers
    • B22F7/04—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite layers with one or more layers not made from powder, e.g. made from solid metal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
    • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D15/00—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies
    • F28D15/02—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes
    • F28D15/04—Heat-exchange apparatus with the intermediate heat-transfer medium in closed tubes passing into or through the conduit walls ; Heat-exchange apparatus employing intermediate heat-transfer medium or bodies in which the medium condenses and evaporates, e.g. heat pipes with tubes having a capillary structure

Definitions

  • the present invention relates to a copper paste, a wick forming method, and a heat pipe.
  • a heat pipe is a passive heat transfer element that utilizes the evaporation and condensation of a working liquid, and is equipped with a working liquid and a member that produces a capillary pumping action called a "wick" in a closed space.
  • Heat pipes are attracting attention as heat-dissipating devices for small information devices such as smartphones because they can transport a large amount of heat with a small temperature difference.
  • Patent Document 1 discloses a heat pipe including a wick composed of a porous sintered powder. When the wick is composed of a porous sintered powder, it is common to deposit a sinterable metal powder (for example, copper powder) in a predetermined place, pressurize and compress it, and then calcin it. be.
  • a sinterable metal powder for example, copper powder
  • one of the objects of the present invention is that it is possible to easily form a wick even when the thickness of the target wick is thin and the formation surface of the target wick has a complicated shape.
  • the purpose is to provide a new method for forming a wick.
  • a wick can be formed by printing by using a copper paste formed by combining two kinds of copper particles having different particle diameters and a pyrolytic resin.
  • the present invention has been completed.
  • one aspect of the present invention relates to the following copper paste for forming a wick in a heat pipe.
  • a copper paste for forming a wick of a heat pipe which contains copper particles, a thermally decomposable resin, and a dispersion medium, and the copper particles have a large diameter of 10 to 50 ⁇ m in volume average particle size.
  • the content of the large-diameter copper particles is 40 to 90% by mass based on the total mass of the copper particles, and the content of the small-diameter copper particles is based on the total mass of the copper particles.
  • the wick can be formed by printing, even when the thickness of the wick is thin (for example, the thickness is 70 ⁇ m or less) or the wick forming surface has a complicated shape. , It is possible to easily form a wick.
  • Another aspect of the present invention is a method for forming a wick of a heat pipe, which is a step of printing the copper paste according to any one of the above [1] to [6] and a step of sintering the copper paste. With respect to a method of forming a wick.
  • Another aspect of the present invention relates to a heat pipe including a wick containing the sintered body of the copper paste according to any one of the above [1] to [6].
  • a new forming method can be provided.
  • the numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively.
  • the upper limit value or the lower limit value of the numerical range of one step may be replaced with the upper limit value or the lower limit value of the numerical range of another step.
  • the materials exemplified in this specification may be used alone or in combination of two or more.
  • the content of each component in the composition is the total amount of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means.
  • the copper paste of one embodiment is a wick forming copper paste used for forming a wick of a heat pipe.
  • the copper paste contains copper particles, a pyrolytic resin, and a dispersion medium.
  • each component contained in the copper paste will be described.
  • the copper particles include copper particles having a volume average particle diameter of 10 to 50 ⁇ m (large diameter copper particles) and copper particles having a volume average particle diameter of 0.1 to 2.0 ⁇ m (small diameter copper particles).
  • the volume average particle size can be obtained by using a light scattering method particle size distribution measuring device.
  • the volume average particle diameter of the large-diameter copper particles may be 10 ⁇ m or more, 15 ⁇ m or more, or 20 ⁇ m or more from the viewpoint that pores of a preferable size (for example, pores of 10 ⁇ m or more) can be easily obtained.
  • the volume average particle diameter of the large-diameter copper particles is 50 ⁇ m or less, 45 ⁇ m or less, even if it is 40 ⁇ m or less, from the viewpoint that a thinner wick (for example, a wick with a thickness of 70 ⁇ m or less) can be easily obtained after firing. good.
  • the volume average particle diameter of the large-diameter copper particles may be 10 to 40 ⁇ m, 20 to 50 ⁇ m, or 20 to 40 ⁇ m.
  • the maximum diameter of the large-diameter copper particles (the particle diameter of the copper particles having the largest particle diameter among the large-diameter copper particles), a thinner wick (for example, a wick having a thickness of 70 ⁇ m or less) can be easily obtained after firing. From the viewpoint, it may be 70 ⁇ m or less, 60 ⁇ m or less, or 50 ⁇ m or less.
  • the maximum diameter of the large-diameter copper particles is a value measured by the sieving method.
  • the percentage on the sieve of large-diameter copper particles obtained by sieving in a test using a sieve with a 63 ⁇ m sieve opening according to JIS Z 8815: 1994 may be 5.0% by mass or less from the viewpoint that a thinner wick (for example, a wick having a thickness of 70 ⁇ m or less) can be easily obtained after firing.
  • the minimum diameter of the large-diameter copper particles is from the viewpoint that pores of a preferable size (for example, pores of 10 ⁇ m or more) can be easily obtained. It may be 0.04 ⁇ m or more, 0.06 ⁇ m or more, or 0.1 ⁇ m or more.
  • the minimum diameter of the large diameter copper particles is measured in the same manner as the maximum diameter.
  • the large-diameter copper particles may be, for example, spherical, lumpy, needle-shaped, flake-shaped, dendritic, substantially spherical, or the like, or may be amorphous.
  • amorphous large-diameter copper particles it becomes easy to obtain a wick having moderately large pores with a high porosity. Therefore, when amorphous large-diameter copper particles are used, the capillary force of the wick tends to be improved.
  • the large-diameter copper particles may have a tap density of 0.5 g / cm 3 or more, 0.8 g / cm 3 or more, or 1.0 g / cm 3 or more, and 4.5 g / cm 3 or less. It may be 4.3 g / cm 3 or less, or 4.0 g / cm 3 or less, and may be 1.0 to 4.5 g / cm 3 or 1.0 to 4.0 g / cm 3 . Such copper particles tend to have an amorphous shape.
  • the tap density of the large diameter copper particles is a value measured according to JIS Z 2512: 2012.
  • the content of the large-diameter copper particles is 40% by mass or more, 60% by mass or more, 70% by mass or more, and 75% by mass based on the total mass of the copper particles from the viewpoint of ensuring a more preferable pore ratio and pore size. % Or 80% by mass or more.
  • the content of the large-diameter copper particles is 90% by mass or less, 87% by mass or less, 85% by mass or less, or 80, based on the total mass of the copper particles, from the viewpoint of improving the balance with the addition amount of the small-diameter copper particles. It may be mass% or less.
  • the content of the large-diameter copper particles is 40 to 90% by mass, 60 to 87% by mass, 70 to 85% by mass, 75 to 80% by mass, or 80 to 85% by mass based on the total mass of the copper particles. May be%.
  • the volume average particle diameter of the small-diameter copper particles may be 0.1 ⁇ m or more, 0.15 ⁇ m or more, or 0.2 ⁇ m or more from the viewpoint of dispersibility and cost.
  • the volume average particle size of the small-diameter copper particles may be 2.0 ⁇ m or less, 1.5 ⁇ m or less, or 1.2 ⁇ m or less from the viewpoint of sufficient sinterability. From the above viewpoint, the volume average particle diameter of the small diameter copper particles may be 0.1 to 1.2 ⁇ m, 0.2 to 2.0 ⁇ m, or 0.2 to 1.2 ⁇ m.
  • the maximum diameter of the small-diameter copper particles (the particle size of the copper particles having the largest particle diameter among the small-diameter copper particles) is 0.1 ⁇ m or more, 0.15 ⁇ m or more, or 0.2 ⁇ m from the viewpoint of dispersibility and cost. That may be the above.
  • the maximum diameter of the small-diameter copper particles may be 2.0 ⁇ m or less, 1.5 ⁇ m or less, or 1.2 ⁇ m or less from the viewpoint of sufficient sinterability.
  • the maximum diameter of the small-diameter copper particles is a value measured in the same manner as the maximum diameter of the large-diameter copper particles.
  • the minimum diameter of the small-diameter copper particles (the particle size of the copper particles having the smallest particle diameter among the small-diameter copper particles) is 0.04 ⁇ m or more, 0.06 ⁇ m or more, or 0.1 ⁇ m from the viewpoint of dispersibility and cost. That may be the above.
  • the minimum diameter of the small diameter copper particles is measured in the same manner as the maximum diameter.
  • the shape of the small-diameter copper particles may be, for example, spherical, lumpy, needle-like, flake-like, dendritic, substantially spherical, or the like.
  • the small-diameter copper particles may be agglomerates of copper particles having these shapes. From the viewpoint of dispersibility and filling property, the shape of the small-diameter copper particles may be spherical, substantially spherical, or flaky.
  • the shape of the small-diameter copper particles may be spherical or substantially spherical from the viewpoint of flammability and from the viewpoint of good mixing with the large-diameter copper particles when the large-diameter copper particles have the above amorphous shape.
  • the content of the small-diameter copper particles may be 10% by mass or more, 15% by mass or more, or 20% by mass or more based on the total mass of the copper particles from the viewpoint of excellent adhesive strength and shape retention of the sintered body. ..
  • the content of the small-diameter copper particles is 60% by mass or less, 30% by mass or less, 27% by mass or less, or 25% by mass based on the total mass of the copper particles from the viewpoint of improving the pore ratio and controlling the pore size. It may be: From the above viewpoint, the content of the small-diameter copper particles may be 10 to 60% by mass, 15 to 30% by mass, 20 to 27% by mass, or 20 to 25% by mass based on the total mass of the copper particles.
  • the mass ratio of the content of the small-diameter copper particles to the content of the large-diameter copper particles is from the viewpoint of excellent adhesive strength and shape retention of the sintered body. It may be 0.1 or more, 0.18 or more, or 0.25 or more.
  • the mass ratio (content of small-diameter copper particles / content of large-diameter copper particles) is 1.0 or less, 0.6 or less, or 0.45 or less from the viewpoint of improving the pore ratio and controlling the pore size. May be. From the above viewpoint, the mass ratio may be 0.1 to 1.0, 0.18 to 0.6 or 0.25 to 0.45.
  • the content of the copper particles may be 70% by mass or more, 75% by mass or more, or 80% by mass or more based on the total mass of the copper paste from the viewpoint of facilitating viscosity adjustment and being superior in printability.
  • the content of the copper particles may be 90% by mass or less, 88% by mass or less, or 85% by mass or less based on the total mass of the copper paste from the viewpoint of facilitating viscosity adjustment and being superior in printability. From the above viewpoint, the content of the copper particles may be 70 to 90% by mass, 75 to 88% by mass, or 80 to 85% by mass based on the total mass of the copper paste.
  • the pyrolytic resin As the pyrolytic resin, a resin having thermal decomposability that can be decomposed at the sintering temperature and decomposed without residue may be used.
  • the 95% pyrolysis temperature of the thermally decomposable resin may be 350 ° C. or lower, 300 ° C. or lower, or 250 ° C. or lower.
  • the 95% thermal decomposition temperature is the 95% weight loss temperature measured in the TG / DTA measurement. This temperature is a temperature measured not in an oxidizing atmosphere such as air, but in a reducing atmosphere containing hydrogen, formic acid and the like, or in an inert gas atmosphere from which oxygen has been removed.
  • the amount of residue (ash content) at the sintering temperature is usually 5% by mass or less and 3% by mass or less with respect to the mass of the resin before thermal decomposition. From the viewpoint of obtaining higher sintering properties, 2 It may be mass% or less.
  • the amount of residue after pyrolysis of the pyrolyzable resin is the weight after holding for the sintering time at the sintering temperature by TG / DTA of the pyrolysis resin in 3 to 5% by mass hydrogen-containing inert gas (nitrogen or argon). It can be measured as the amount of change. It should be noted that TG / DTA measurement in air is not preferable because oxidative decomposition proceeds and the amount of residue is smaller than the amount of residue in the reducing atmosphere.
  • the pyrolytic resin may have solubility in the dispersion medium described later.
  • examples of the pyrolytic resin having solubility in the dispersion medium include polycarbonate, poly (meth) acrylic acid, poly (meth) acrylic acid ester, polyester and the like.
  • a polymethacrylic acid ester may be selected from the viewpoint of solubility in an organic solvent, cost, and thermal decomposability.
  • (meth) acrylic means at least one of acrylic and corresponding methacryl.
  • the content of the pyrolytic resin may be 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more with respect to 100 parts by mass of the copper particles from the viewpoint of excellent shape retention after printing and drying. ..
  • the content of the pyrolytic resin is 20 parts by mass or less, 15 parts by mass or less, or 12 parts by mass or less with respect to 100 parts by mass of copper particles from the viewpoint of easy adjustment of viscosity and excellent sinterability. It may be there. From the above viewpoint, the content of the pyrolytic resin may be 1 to 20 parts by mass, 2 to 15 parts by mass, or 3 to 12 parts by mass with respect to 100 parts by mass of the copper particles.
  • the dispersion medium is not particularly limited and may be, for example, volatile.
  • volatile dispersion medium include pentanol, hexanol, heptanol, octanol, decanol, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, ⁇ -terpineol, dihydroterpineol, and isobornylcyclohexanol (MTPH).
  • Valuable and polyhydric alcohols ethylene glycol butyl ether, ethylene glycol phenyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, diethylene glycol isobutyl ether, diethylene glycol hexyl ether, triethylene glycol methyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di Butyl ether, diethylene glycol butyl methyl ether, diethylene glycol isopropyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, propylene glycol propyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol propyl ether, dipropylene glycol Ethers such as butyl ether, dipropylene glycol dimethyl ether, tripropylene glycol
  • Examples of mercaptans having an alkyl group having 1 to 18 carbon atoms include ethyl mercaptan, n-propyl mercaptan, i-propyl mercaptan, n-butyl mercaptan, i-butyl mercaptan, t-butyl mercaptan, pentyl mercaptan, and hexyl mercaptan. And dodecyl mercaptan.
  • Examples of mercaptans having a cycloalkyl group having 5 to 7 carbon atoms include cyclopentyl mercaptan, cyclohexyl mercaptan and cycloheptyl mercaptan.
  • the content of the dispersion medium may be, for example, 5 to 50 parts by mass with respect to 100 parts by mass of the copper particles.
  • the copper paste can be adjusted to a more appropriate viscosity, and the sintering of copper particles is less likely to be hindered.
  • the copper paste may further contain other metal particles other than the copper particles.
  • other metal particles include particles such as nickel, silver, gold, palladium, and platinum.
  • the content of the other metal particles may be 0% by mass, 0% by mass or more and less than 20% by mass, and 0 to 10% by mass, based on the total mass of the metal particles contained in the copper paste. It may be 0 to 5% by mass.
  • the copper paste contains other metal particles, the content with respect to 100 parts by mass of the copper particles may be read as the content with respect to 100 parts by mass of the metal particles in the present specification, and is based on the total mass of the copper particles. The content may be read as the content based on the total mass of the metal particles.
  • dispersibility improvers such as organic acids (for example, lauric acid) and organic amines, wetting improvers such as nonionic surfactants and fluorine-based surfactants; defoaming of silicone oil and the like.
  • An ion trapping agent such as an inorganic ion exchanger may be appropriately added.
  • the viscosity of the copper paste may be 10 to 120 Pa ⁇ s from the viewpoint of printability.
  • the viscosity is a value measured by an E-type viscometer at 25 ° C. and a rotation speed of 2.5 rpm.
  • the E-type viscometer for example, a product name: VISCOMETER-TV33 type viscometer manufactured by Toki Sangyo Co., Ltd. can be used.
  • As a jig for measuring the cone rotor for example, 3 ° ⁇ R14, SPP can be applied.
  • the thixotropy index (hereinafter, also referred to as TI value) of the copper paste may be 2.0 to 20, 3.0 to 15, or 4.0 to 10. If the TI value of the copper paste is within the above range, the viscosity of the copper paste tends to decrease due to the shearing force. It becomes easier to print by stirring with (manufactured by company Shinky) etc.). In addition, after the copper paste adheres to the member to be adhered, the viscosity can be easily recovered by standing, so that excessive wetting and spreading of the printed matter can be suppressed.
  • the above-mentioned copper paste can be prepared by mixing large-diameter copper particles, small-diameter copper particles, a pyrolytic resin, a dispersion medium, and other components.
  • the copper paste may be prepared, for example, by dissolving a thermally decomposable resin in a dispersion medium and then adding large-diameter copper particles and small-diameter copper particles to perform a dispersion treatment, and the thermally decomposable resin is dissolved in the dispersion medium.
  • the solution obtained by mixing the large-diameter copper particles and the small-diameter copper particles with the dispersion medium and the dispersion liquid obtained by the dispersion treatment may be mixed and prepared. After mixing each component, stirring treatment may be performed.
  • the maximum diameter of the dispersion may be adjusted by a classification operation.
  • the dispersion treatment can be performed using a disperser or a stirrer.
  • the disperser and stirrer that can be used in the dispersion treatment include Ishikawa stirrer, Silberson stirrer, cavitation stirrer, rotation and revolution type stirrer, ultrathin high-speed rotary disperser, ultrasonic disperser, Raikai machine, and biaxial kneading.
  • Machines, bead mills, ball mills, three-roll mills, homomixers, planetary mixers, ultra-high pressure dispersers and thin layer shear dispersers can be mentioned.
  • the stirring process can be performed using a stirrer.
  • the stirrer that can be used in the stirring process include an Ishikawa type stirrer, a rotation / revolution type stirrer, a Raikai machine, a twin-screw kneader, a three-roll mill and a planetary mixer.
  • the classification operation can be performed using, for example, filtration, natural sedimentation, centrifugation, or the like.
  • the filter for filtration include a water comb, a metal mesh, a metal filter and a nylon mesh.
  • the wick forming method of one embodiment includes a step of printing a copper paste and a step of sintering the copper paste.
  • the copper paste of the above embodiment can be used.
  • a wick containing a sintered body of the copper paste can be obtained.
  • the printing method of copper paste is not particularly limited.
  • Barcoats, applicators, particle deposition methods, spray coaters, spin coaters, dip coaters, electrodeposition coatings and the like can be used to print copper pastes.
  • the method of sintering the copper paste is not particularly limited.
  • the copper paste can be sintered by heat-treating (baking) the copper paste using a heating furnace or the like.
  • the gas atmosphere during the heat treatment may be an oxygen-free atmosphere from the viewpoint of suppressing the oxidation of the obtained sintered body.
  • the gas atmosphere during the heat treatment may be a reducing atmosphere from the viewpoint of removing the surface oxides of the copper particles in the copper paste.
  • the oxygen-free atmosphere include an atmosphere of nitrogen, a rare gas, and a vacuum atmosphere.
  • the reducing atmosphere include a pure hydrogen gas atmosphere, a mixed gas atmosphere of hydrogen and nitrogen typified by forming gas, a nitrogen atmosphere containing formic acid gas, a mixed gas atmosphere of hydrogen and rare gas, a rare gas atmosphere containing formic acid gas, and the like. Can be mentioned.
  • the maximum temperature reached during the heat treatment may be 150 to 700 ° C., 200 to 600 ° C., or 250 to 550 ° C. from the viewpoint of reducing heat damage to each member and improving the yield. You may. When the maximum ultimate temperature is 150 ° C. or higher, sintering tends to proceed sufficiently when the maximum ultimate temperature holding time is 60 minutes or less.
  • the maximum temperature retention time may be 1 to 60 minutes, 1 minute or more and less than 40 minutes, or 1 minute or more and 30 minutes or more from the viewpoint of volatilizing all the dispersion medium and improving the yield. It may be less than a minute.
  • the wick forming method may further include a step of drying the copper paste before the step of sintering the copper paste.
  • the gas atmosphere at the time of drying may be in the atmosphere, an oxygen-free atmosphere such as nitrogen or a rare gas, or a reducing atmosphere such as hydrogen or formic acid.
  • the drying method may be drying by leaving at room temperature, heat drying, or vacuum drying.
  • Heat drying and vacuum drying include, for example, hot plates, hot air dryers, hot air heating furnaces, nitrogen dryers, infrared dryers, infrared heating furnaces, far infrared heating furnaces, microwave heating devices, laser heating devices, electromagnetic waves.
  • a heating device, a heater heating device, a steam heating furnace, a hot plate pressing device, or the like can be used.
  • the drying conditions (temperature and time) may be appropriately adjusted according to the type and amount of the dispersion medium used.
  • the drying conditions (temperature and time) may be, for example, conditions for drying at 50 to 180 ° C. for 1 to 120 minutes.
  • the wick forming surface has a complicated shape (for example, a concave-convex shape, a curved shape, and a shape having a V-shaped concave portion). Etc.), the wick can be easily formed. Further, in the above method, since the copper particles contain large-diameter copper particles and small-diameter copper particles, sufficient sinterability and shape retention can be obtained without applying pressure during sintering. Therefore, the above method can obtain high productivity as compared with the conventional method requiring pressurization.
  • the degree of freedom in the shape of the wick that can be formed is high, for example, a wick having a thinner film can be formed, and a wick having a more complicated shape (for example, a shape having a curved portion) can be formed. It becomes easy to form.
  • the heat pipe of one embodiment includes a wick containing a sintered body of the copper paste of the above embodiment.
  • the structure of the heat pipe excluding the wick can be the same as that of a conventionally known heat pipe (vapor chamber or the like).
  • the wick containing the sintered body of the copper paste can be formed according to the wick forming method of the above embodiment. That is, the heat pipe can be manufactured by the same method as the conventionally known heat pipe except for the wick forming step.
  • a heat pipe will be described with reference to the drawings.
  • FIG. 1 is a schematic cross-sectional view showing a heat pipe of one embodiment.
  • the heat pipe 1 includes a container 2 that defines a closed space S, a wick 3 housed in the space S of the container 2, and a working liquid.
  • a gas phase space A is secured so that the vaporized product of the working liquid vaporized by the heat source can flow.
  • the working liquid is, for example, water or an organic solvent and is impregnated in Wick 3.
  • the shape of the container 2 is not particularly limited, and may be tubular, flat plate, or the like.
  • a heat pipe may be formed by the following method. First, a copper paste is printed on the recesses of the first base material having recesses formed on the surface to form a wick. Next, the first base material and the second base material having recesses formed on the surface are bonded to each other so that the recesses face each other. As a result, the heat pipe 1 including the flat plate-shaped container 2 can be obtained.
  • the material of the container 2 may be metal from the viewpoints of thermal conductivity, pressure resistance, gas shielding property, workability, and the like.
  • the metal for example, copper, copper alloy, aluminum, stainless steel, carbon steel and the like are used.
  • the wick 3 is arranged on the inner wall surface of the container 2.
  • Wick 3 is a porous body obtained by sintering the copper paste of the above embodiment. Therefore, the wick 3 contains a sintered body of the copper paste of the above embodiment.
  • the wick 3 may be integrally formed with the container 2, or may be a preformed one (separately arranged one).
  • the porosity of the wick 3 is 40% by volume or more, 45% by volume or more, or 50% by volume based on the volume of the wick from the viewpoint of ease of circulation of the working liquid due to the capillary phenomenon. It may be% or more.
  • the porosity of the wick 3 (porosity of the sintered body) is not particularly limited, but may be, for example, 90% by volume or less or 80% by volume or less based on the volume of the wick. That is, the porosity of the wick 3 (porosity of the sintered body) may be, for example, 40 to 80% by volume, 45 to 80% by volume, or 50 to 80% by volume based on the volume of the wick.
  • the average pore diameter of Wick 3 may be 10 ⁇ m or more, 15 ⁇ m or more, or 20 ⁇ m or more from the viewpoint of improving the balance between flow resistance and capillary force.
  • the average pore diameter of the wick 3 may be 50 ⁇ m or less, 45 ⁇ m or less, or 40 ⁇ m or less from the viewpoint of improving the balance between the flow resistance and the capillary force and facilitating the thinning of the wick. From the above viewpoint, the average pore diameter of the wick 3 may be 10 to 50 ⁇ m, 15 to 45 ⁇ m, or 20 to 40 ⁇ m.
  • the average pore diameter is obtained by measuring the length of the pores in the SEM image of the cross section processed by casting.
  • the wick 3 may have two or more peaks in the pore size distribution obtained by measuring the length of the pores in the SEM image of the cross section processed by casting. Specifically, for example, it may have a first peak at 0.5 to 5 ⁇ m and a second peak at 10 to 50 ⁇ m. When having such a pore peak, a strong capillary force is obtained by the small pores having the first peak, and a large amount of liquid can be transported quickly by the large pore having the second peak.
  • the heat pipe described above is used, for example, with a heat radiating member provided on the outer wall of the container.
  • the heat pipe is suitably used as a heat radiating device for small information devices such as smartphones and tablets.
  • Dihydroterpineol manufactured by Nippon Terupen Chemical Co., Ltd.
  • Reciprocal chemicals 3.0 g
  • CH-0200 (manufactured by Mitsui Metal Mining Co., Ltd., volume average particle size: 0.36 ⁇ m) 17.0 g as small-diameter copper particles and CuAtW-250 (manufactured by Fukuda Metal Foil Powder Industry) as large-diameter copper particles in this dispersion.
  • Volume average particle size: 27 ⁇ m 68 g was added, and the mixture was stirred at 2000 rpm for 1 minute using a rotation / revolution type stirrer (Planetry Vacuum Mixer ARV-310, manufactured by Shinky Co., Ltd.).
  • the viscosity of the copper paste was 32 Pa ⁇ s.
  • the viscosity was measured using an E-type viscometer (VISCOMETER TV-33 manufactured by Toki Sangyo Co., Ltd.) equipped with an SPP rotor under the conditions of a temperature of 25 ° C. and a rotation speed of 2.5 rotations / min.
  • the viscosity value is the viscosity value after 144 seconds have passed from the start of measurement (JIS3284).
  • Examples 2 to 4 and Comparative Example 1 A copper paste was prepared in the same manner as in Example 1 except that the blending amount of the large-diameter copper particles and the blending amount of the small-diameter copper particles were changed to the amounts shown in Table 1.
  • the blending amount (unit: parts by mass) shown in the table is the amount of solid content.
  • Example 5 The amount of large-diameter copper particles and the amount of small-diameter copper particles and lauric acid were changed to the amounts shown in Table 2.
  • tarpineol C ⁇ -, ⁇ -, ⁇ -terpineol
  • An isomer mixture (manufactured by Nippon Terupen Chemical Co., Ltd., trade name) was used in the amount shown in Table 2, and the amount of M-6003 (molecular weight) shown in Table 2 was used instead of KFA-2000 as the pyrolytic resin.
  • a copper paste was prepared in the same manner as in Example 1.
  • the viscosity of the copper paste measured in the same manner as in Example 1 was 63 Pa ⁇ s.
  • Example 6> The amount of large-diameter copper particles and the amount of lauric acid were changed to the amounts shown in Table 2, and as small-diameter copper particles, CT-0500 (manufactured by Mitsui Metal Mining Co., Ltd., volume average particle size) was used instead of CH-0200. : 1.11 ⁇ m) was used in the amount shown in Table 2, and as a dispersion medium, tarpineol C ( ⁇ -, ⁇ -, ⁇ -terpineol isomer mixture, manufactured by Nippon Terpen Chemical Co., Ltd., trade name) was used instead of dihydroterpineol.
  • CT-0500 manufactured by Mitsui Metal Mining Co., Ltd., volume average particle size
  • tarpineol C ⁇ -, ⁇ -, ⁇ -terpineol isomer mixture, manufactured by Nippon Terpen Chemical Co., Ltd., trade name
  • tarpineol C a mixture of ⁇ -, ⁇ -, ⁇ -terpineol isomers, manufactured by Nippon Terpine Chemical Co., Ltd., trade name
  • M-6003 manufactured by Negami Kogyo
  • CT-0500 manufactured by Mitsui Mining & Smelting Co., Ltd., volume average particle size: 1.11 ⁇ m
  • a planetary mixer TK HIVIS MIX format.03, PRIMIX
  • ⁇ Comparative example 2> The blending amounts of large-diameter copper particles, small-diameter copper particles, and lauric acid were changed to the values shown in Table 2, and as a dispersion medium, terpineol C ( ⁇ -, ⁇ -, ⁇ -terpineol isomer mixture) was used instead of dihydroterpineol. , Nippon Terpene Chemical Co., Ltd., trade name) was used in the amounts shown in Table 2, and the copper paste was used in the same manner as in Example 1 except that the pyrolytic resin (KFA-2000) was not used. Was produced.
  • printability A the case where continuous and uniform ejection printing is possible is defined as printability A
  • printability B the case where ejection is intermittent or very slow is defined as printability B
  • printability C the case where ejection is not possible or the ejection is stopped during ejection.
  • printability (2) The results are shown in Tables 1 and 2 as printability (2).
  • Adhesion evaluation (tape peeling test)
  • a 16 mm wide cellophane tape (registered trademark) manufactured by Nichiban Co., Ltd. was attached onto the sintered body obtained above, and the tape was rubbed firmly with a fingertip for about 10 seconds. Then, within 30 seconds or more and 5 minutes or less, the edge of the tape was grasped at an angle as close to 60 ° as possible, and the tape was peeled off in 0.5 to 1.0 seconds to confirm adhesion to the tape. The case where there was no deposit was determined as A, the case where there was a small amount of deposit was determined as B, and the case where the deposit was formed on the entire surface was determined as C. The results are shown in Tables 1 and 2.
  • the cross section was ground with a polishing device (Refine Polisher Hv, manufactured by Refine Tech Co., Ltd.) equipped with water-resistant polishing paper (Carbomac Paper, manufactured by Refine Tech Co., Ltd.), and buffing was performed using an alumina polishing liquid.
  • This sample was observed with an SEM device (TM-1000, manufactured by Hitachi High-Technologies Corporation) at an applied voltage of 15 kV and various magnifications.
  • the observed image was binarized by Image J, and the porosity (unit: volume%) of the sintered body (wick) was obtained from the ratio of the number of dots in the white part and the black part.
  • Tables 1 and 2 The results are shown in Tables 1 and 2.
  • FIG. 2 shows an SEM image of Example 7.
  • FIG. 2A is a 500-fold SEM image
  • FIG. 2B is a 10000-fold SEM image.
  • Example 1 it was confirmed that the pore diameter peaks were at 1.2 ⁇ m and 20 ⁇ m.
  • Example 6 it was confirmed that the pore diameter peaks were present at 1.0 ⁇ m and 30 ⁇ m.
  • Example 7 it was confirmed that the pore diameter peaks were at 1.1 ⁇ m and 30 ⁇ m.

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Abstract

A copper paste for forming wick of a heat pipe, the copper paste containing copper particles, a thermally decomposable resin and a dispersion medium, the copper particles including a copper particle of a larger diameter having a volume-average particle diameter of 10-50 μm and a copper particle of a smaller diameter having a volume-average particle diameter of 0.1-2.0 μm.

Description

銅ペースト、ウィックの形成方法及びヒートパイプCopper paste, wick formation method and heat pipe
　本発明は、銅ペースト、ウィックの形成方法及びヒートパイプに関する。 The present invention relates to a copper paste, a wick forming method, and a heat pipe.
　ヒートパイプは、作動液体の蒸発と凝縮を利用した受動的伝熱素子であり、密閉された空間内に、作動液体と、「ウィック」とよばれる毛細管ポンプ作用を生み出す部材と、を備えている。ヒートパイプは、小さな温度差で大量の熱を輸送できることから、スマートフォン等のような小型情報機器用の放熱デバイスとして注目されている。例えば、特許文献１には、多孔質の焼結粉末で構成されるウィックを備えるヒートパイプが開示されている。ウィックを多孔質の焼結粉末で構成する場合、焼結性の金属粉末（例えば銅粉）を所定箇所に堆積させた後、加圧圧縮し、焼成することで焼結させる方法が一般的である。 A heat pipe is a passive heat transfer element that utilizes the evaporation and condensation of a working liquid, and is equipped with a working liquid and a member that produces a capillary pumping action called a "wick" in a closed space. .. Heat pipes are attracting attention as heat-dissipating devices for small information devices such as smartphones because they can transport a large amount of heat with a small temperature difference. For example, Patent Document 1 discloses a heat pipe including a wick composed of a porous sintered powder. When the wick is composed of a porous sintered powder, it is common to deposit a sinterable metal powder (for example, copper powder) in a predetermined place, pressurize and compress it, and then calcin it. be.
特開２００３－２２２４８１号公報Japanese Unexamined Patent Publication No. 2003-222481
　ヒートパイプの形状は旧来パイプ状のものが多く用いられていたが、小型化、熱源との密着性等の観点から、ベーパーチャンバーと呼ばれる、平板状のヒートパイプも用いられるようになってきている。このような平板状のヒートパイプでは、小型情報機器の容積の制約から薄型化が進んでおり、ウィックの厚みも薄く成形することが求められる。さらに、平板状のヒートパイプでは、ウィックが形成される面（ウィックの形成面）が凹凸形状等の複雑な形状を有する場合がある。しかしながら、ウィックを多孔質の焼結粉末で構成する場合、従来の加圧圧縮する方法では、このような薄厚のウィック及び複雑な形状のウィックへの対応が困難である。 Traditionally, pipe-shaped heat pipes have been often used, but from the viewpoint of miniaturization, adhesion to heat sources, etc., flat-plate heat pipes called vapor chambers are also being used. .. Such a flat plate-shaped heat pipe is becoming thinner due to the limitation of the volume of a small information device, and it is required to form a wick with a thin thickness. Further, in a flat plate heat pipe, the surface on which the wick is formed (the surface on which the wick is formed) may have a complicated shape such as an uneven shape. However, when the wick is composed of a porous sintered powder, it is difficult to cope with such a thin wick and a wick having a complicated shape by the conventional pressure compression method.
　そこで、本発明の目的の一つは、目的とするウィックの厚さが薄い場合及び目的とするウィックの形成面が複雑な形状を有する場合であっても、簡便にウィックを形成することを可能とする、ウィックの新規形成方法を提供することにある。 Therefore, one of the objects of the present invention is that it is possible to easily form a wick even when the thickness of the target wick is thin and the formation surface of the target wick has a complicated shape. The purpose is to provide a new method for forming a wick.
　本発明者らの検討の結果、粒径の異なる２種の銅粒子と熱分解性樹脂とを組み合わせてなる銅ペーストを用いることで、印刷によりウィックを形成することが可能であることを見出し、本発明を完成させた。 As a result of the studies by the present inventors, it has been found that a wick can be formed by printing by using a copper paste formed by combining two kinds of copper particles having different particle diameters and a pyrolytic resin. The present invention has been completed.
　すなわち、本発明の一側面は、以下に示すヒートパイプのウィック形成用銅ペーストに関する。 That is, one aspect of the present invention relates to the following copper paste for forming a wick in a heat pipe.
［１］ヒートパイプのウィック形成用銅ペーストであって、銅粒子と、熱分解性樹脂と、分散媒と、を含有し、前記銅粒子は、体積平均粒径が１０～５０μｍである大径銅粒子と、体積平均粒径が０．１～２．０μｍである小径銅粒子と、を含む、銅ペースト。 [1] A copper paste for forming a wick of a heat pipe, which contains copper particles, a thermally decomposable resin, and a dispersion medium, and the copper particles have a large diameter of 10 to 50 μm in volume average particle size. A copper paste containing copper particles and small-diameter copper particles having a volume average particle diameter of 0.1 to 2.0 μm.
［２］前記熱分解性樹脂の９５％熱分解温度が３５０℃以下である、［１］に記載の銅ペースト。 [2] The copper paste according to [1], wherein the 95% pyrolysis temperature of the thermally decomposable resin is 350 ° C. or lower.
［３］前記大径銅粒子の含有量が、前記銅粒子の全質量を基準として、４０～９０質量％であり、前記小径銅粒子の含有量が、前記銅粒子の全質量を基準として、１０～６０質量％である、［１］又は［２］に記載の銅ペースト。 [3] The content of the large-diameter copper particles is 40 to 90% by mass based on the total mass of the copper particles, and the content of the small-diameter copper particles is based on the total mass of the copper particles. The copper paste according to [1] or [2], which is 10 to 60% by mass.
　［４］前記熱分解性樹脂の含有量が、前記銅粒子１００質量部に対して、１～２０質量部である、［１］～［３］のいずれかに記載の銅ペースト。 [4] The copper paste according to any one of [1] to [3], wherein the content of the pyrolytic resin is 1 to 20 parts by mass with respect to 100 parts by mass of the copper particles.
［５］前記大径銅粒子は、タップ密度が１．０～４．５ｇ／ｃｍ３である、［１］～［４］のいずれかに記載の銅ペースト。 [5] The copper paste according to any one of [1] to [4], wherein the large-diameter copper particles have a tap density of 1.0 to 4.5 g / cm 3.
［６］前記銅ペーストの粘度が、１０～１２０Ｐａ・ｓである、［１］～［５］のいずれかに記載の銅ペースト。 [6] The copper paste according to any one of [1] to [5], wherein the copper paste has a viscosity of 10 to 120 Pa · s.
　上記銅ペーストによれば、印刷によりウィックを形成することが可能であるため、ウィックの厚さが薄い（例えば７０μｍ以下の厚さである）場合及びウィックの形成面が複雑な形状を有する場合でも、簡便にウィックを形成することが可能である。 According to the copper paste, since the wick can be formed by printing, even when the thickness of the wick is thin (for example, the thickness is 70 μm or less) or the wick forming surface has a complicated shape. , It is possible to easily form a wick.
　本発明の他の一側面は、ヒートパイプのウィックの形成方法であって、上記［１］～［６］のいずれかに記載の銅ペーストを印刷する工程と、前記銅ペーストを焼結させる工程と、を備える、ウィックの形成方法に関する。 Another aspect of the present invention is a method for forming a wick of a heat pipe, which is a step of printing the copper paste according to any one of the above [1] to [6] and a step of sintering the copper paste. With respect to a method of forming a wick.
　本発明の他の一側面は、上記［１］～［６］のいずれかに記載の銅ペーストの焼結体を含むウィックを備える、ヒートパイプに関する。 Another aspect of the present invention relates to a heat pipe including a wick containing the sintered body of the copper paste according to any one of the above [1] to [6].
　本発明によれば、目的とするウィックの厚さが薄い場合及び目的とするウィックの形成面が複雑な形状を有する場合であっても、簡便にウィックを形成することを可能とする、ウィックの新規形成方法を提供することができる。 According to the present invention, it is possible to easily form a wick even when the thickness of the target wick is thin and the formation surface of the target wick has a complicated shape. A new forming method can be provided.
一実施形態のヒートパイプを示す模式断面図である。It is a schematic cross-sectional view which shows the heat pipe of one Embodiment. 実施例の焼結体（ウィック）の断面ＳＥＭ画像を示す図である。It is a figure which shows the cross-sectional SEM image of the sintered body (wick) of an Example.
　本明細書において、「～」を用いて示された数値範囲は、「～」の前後に記載される数値をそれぞれ最小値及び最大値として含む範囲を示す。本明細書中に段階的に記載されている数値範囲において、ある段階の数値範囲の上限値又は下限値は、他の段階の数値範囲の上限値又は下限値に置き換えてもよい。また、本明細書に例示する材料は、特に断らない限り、１種を単独で又は２種以上を組み合わせて用いることができる。本明細書において、組成物中の各成分の含有量は、組成物中に各成分に該当する物質が複数存在する場合、特に断らない限り、組成物中に存在する当該複数の物質の合計量を意味する。 In the present specification, the numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively. In the numerical range described stepwise in the present specification, the upper limit value or the lower limit value of the numerical range of one step may be replaced with the upper limit value or the lower limit value of the numerical range of another step. Further, unless otherwise specified, the materials exemplified in this specification may be used alone or in combination of two or more. In the present specification, the content of each component in the composition is the total amount of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means.
　以下、本発明の好適な実施形態について説明する。ただし、本発明は下記実施形態に何ら限定されるものではない。 Hereinafter, preferred embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments.
＜銅ペースト＞
　一実施形態の銅ペーストは、ヒートパイプのウィックの形成に用いられる、ウィック形成用銅ペーストである。銅ペーストは、銅粒子と、熱分解性樹脂と、分散媒と、を含有する。以下、銅ペーストに含まれる各成分について説明する。 <Copper paste>
The copper paste of one embodiment is a wick forming copper paste used for forming a wick of a heat pipe. The copper paste contains copper particles, a pyrolytic resin, and a dispersion medium. Hereinafter, each component contained in the copper paste will be described.
（銅粒子）
　銅粒子は、体積平均粒径が１０～５０μｍである銅粒子（大径銅粒子）と、体積平均粒径が０．１～２．０μｍである銅粒子（小径銅粒子）と、を含む。ここで、体積平均粒径は、光散乱法粒度分布測定装置を用いて求めることができる。 (Copper particles)
The copper particles include copper particles having a volume average particle diameter of 10 to 50 μm (large diameter copper particles) and copper particles having a volume average particle diameter of 0.1 to 2.0 μm (small diameter copper particles). Here, the volume average particle size can be obtained by using a light scattering method particle size distribution measuring device.
　大径銅粒子の体積平均粒径は、好ましいサイズの空孔（例えば１０μｍ以上の空孔）が得られやすい観点から、１０μｍ以上であり、１５μｍ以上であり、２０μｍ以上であってもよい。大径銅粒子の体積平均粒径は、焼成後により薄厚のウィック（例えば７０μｍ以下の厚さのウィック）が得られやすい観点から、５０μｍ以下であり、４５μｍ以下であり、４０μｍ以下であってもよい。上記観点から、大径銅粒子の体積平均粒径は、１０～４０μｍ、２０～５０μｍ又は２０～４０μｍであってもよい。 The volume average particle diameter of the large-diameter copper particles may be 10 μm or more, 15 μm or more, or 20 μm or more from the viewpoint that pores of a preferable size (for example, pores of 10 μm or more) can be easily obtained. The volume average particle diameter of the large-diameter copper particles is 50 μm or less, 45 μm or less, even if it is 40 μm or less, from the viewpoint that a thinner wick (for example, a wick with a thickness of 70 μm or less) can be easily obtained after firing. good. From the above viewpoint, the volume average particle diameter of the large-diameter copper particles may be 10 to 40 μm, 20 to 50 μm, or 20 to 40 μm.
　大径銅粒子の最大径（大径銅粒子の中で最大の粒子径を有する銅粒子の当該粒子径）は、焼成後により薄厚のウィック（例えば７０μｍ以下の厚さのウィック）が得られやすい観点から、７０μｍ以下、６０μｍ以下、又は５０μｍ以下であってよい。大径銅粒子の最大径は、ふるい分け法により測定される値である。 As for the maximum diameter of the large-diameter copper particles (the particle diameter of the copper particles having the largest particle diameter among the large-diameter copper particles), a thinner wick (for example, a wick having a thickness of 70 μm or less) can be easily obtained after firing. From the viewpoint, it may be 70 μm or less, 60 μm or less, or 50 μm or less. The maximum diameter of the large-diameter copper particles is a value measured by the sieving method.
　大径銅粒子の最大径の判定方法として、ＪＩＳ　Ｚ　８８１５：１９９４に従い、６３μｍのふるい目開きのふるいを用いた試験でふるい分けして得られる大径銅粒子のふるい上百分率を用いる方法もある。この方法で得られる大径銅粒子のふるい上百分率は、焼成後により薄厚のウィック（例えば７０μｍ以下の厚さのウィック）が得られやすい観点から、５．０質量％以下であってよい。 As a method for determining the maximum diameter of large-diameter copper particles, there is also a method of using the percentage on the sieve of large-diameter copper particles obtained by sieving in a test using a sieve with a 63 μm sieve opening according to JIS Z 8815: 1994. The percentage on the sieve of the large-diameter copper particles obtained by this method may be 5.0% by mass or less from the viewpoint that a thinner wick (for example, a wick having a thickness of 70 μm or less) can be easily obtained after firing.
　大径銅粒子の最小径（大径銅粒子の中で最小の粒子径を有する銅粒子の当該粒子径）は、好ましいサイズの空孔（例えば１０μｍ以上の空孔）が得られやすい観点から、０．０４μｍ以上、０．０６μｍ以上、又は０．１μｍ以上であってよい。大径銅粒子の最小径は、最大径と同様にして測定される。 The minimum diameter of the large-diameter copper particles (the particle diameter of the copper particles having the smallest particle diameter among the large-diameter copper particles) is from the viewpoint that pores of a preferable size (for example, pores of 10 μm or more) can be easily obtained. It may be 0.04 μm or more, 0.06 μm or more, or 0.1 μm or more. The minimum diameter of the large diameter copper particles is measured in the same manner as the maximum diameter.
　大径銅粒子は、例えば、球状、塊状、針状、フレーク状、樹枝状、略球状等であってよく、不定形であってもよい。不定形の大径銅粒子を用いる場合、高い空孔率で適度に大きな空孔を有するウィックが得られやすくなる。そのため、不定形の大径銅粒子を用いる場合、ウィックの毛管力が向上しやすい。かかる観点から、大径銅粒子は、タップ密度が、０．５ｇ／ｃｍ３以上、０．８ｇ／ｃｍ３以上又は１．０ｇ／ｃｍ３以上であってよく、４．５ｇ／ｃｍ３以下、４．３ｇ／ｃｍ３以下、又は４．０ｇ／ｃｍ３以下であってよく、１．０～４．５ｇ／ｃｍ３又は１．０～４．０ｇ／ｃｍ３であってよい。このような銅粒子は、不定形を有する傾向がある。大径銅粒子のタップ密度は、ＪＩＳ　Ｚ　２５１２：２０１２に従って測定される値である。 The large-diameter copper particles may be, for example, spherical, lumpy, needle-shaped, flake-shaped, dendritic, substantially spherical, or the like, or may be amorphous. When amorphous large-diameter copper particles are used, it becomes easy to obtain a wick having moderately large pores with a high porosity. Therefore, when amorphous large-diameter copper particles are used, the capillary force of the wick tends to be improved. From this point of view, the large-diameter copper particles may have a tap density of 0.5 g / cm 3 or more, 0.8 g / cm 3 or more, or 1.0 g / cm 3 or more, and 4.5 g / cm 3 or less. It may be 4.3 g / cm 3 or less, or 4.0 g / cm 3 or less, and may be 1.0 to 4.5 g / cm 3 or 1.0 to 4.0 g / cm 3 . Such copper particles tend to have an amorphous shape. The tap density of the large diameter copper particles is a value measured according to JIS Z 2512: 2012.
　大径銅粒子の含有量は、より好ましい空孔率及び空孔サイズを確保する観点から、銅粒子の全質量を基準として、４０質量％以上、６０質量％以上、７０質量％以上、７５質量％又は８０質量％以上であってよい。大径銅粒子の含有量は、小径銅粒子の添加量とのバランスが良好となる観点から、銅粒子の全質量を基準として、９０質量％以下、８７質量％以下、８５質量％以下又は８０質量％以下であってよい。上記観点から、大径銅粒子の含有量は、銅粒子の全質量を基準として、４０～９０質量％、６０～８７質量％、７０～８５質量％、７５～８０質量％又は８０～８５質量％であってよい。 The content of the large-diameter copper particles is 40% by mass or more, 60% by mass or more, 70% by mass or more, and 75% by mass based on the total mass of the copper particles from the viewpoint of ensuring a more preferable pore ratio and pore size. % Or 80% by mass or more. The content of the large-diameter copper particles is 90% by mass or less, 87% by mass or less, 85% by mass or less, or 80, based on the total mass of the copper particles, from the viewpoint of improving the balance with the addition amount of the small-diameter copper particles. It may be mass% or less. From the above viewpoint, the content of the large-diameter copper particles is 40 to 90% by mass, 60 to 87% by mass, 70 to 85% by mass, 75 to 80% by mass, or 80 to 85% by mass based on the total mass of the copper particles. May be%.
　小径銅粒子の体積平均粒径は、分散性及びコストの観点から、０．１μｍ以上であり、０．１５μｍ以上であり、０．２μｍ以上であってもよい。小径銅粒子の体積平均粒径は、充分な焼結性発現の観点から、２．０μｍ以下であり、１．５μｍ以下であり、１．２μｍ以下であってもよい。上記観点から、小径銅粒子の体積平均粒径は、０．１～１．２μｍ、０．２～２．０μｍ又は０．２～１．２μｍであってもよい。 The volume average particle diameter of the small-diameter copper particles may be 0.1 μm or more, 0.15 μm or more, or 0.2 μm or more from the viewpoint of dispersibility and cost. The volume average particle size of the small-diameter copper particles may be 2.0 μm or less, 1.5 μm or less, or 1.2 μm or less from the viewpoint of sufficient sinterability. From the above viewpoint, the volume average particle diameter of the small diameter copper particles may be 0.1 to 1.2 μm, 0.2 to 2.0 μm, or 0.2 to 1.2 μm.
　小径銅粒子の最大径（小径銅粒子の中で最大の粒子径を有する銅粒子の当該粒子径）は、分散性及びコストの観点から、０．１μｍ以上、０．１５μｍ以上、又は０．２μｍ以上であってよい。小径銅粒子の最大径は、充分な焼結性発現の観点から、２．０μｍ以下、１．５μｍ以下、又は１．２μｍ以下であってよい。小径銅粒子の最大径は、大径銅粒子の最大径と同様にして測定される値である。 The maximum diameter of the small-diameter copper particles (the particle size of the copper particles having the largest particle diameter among the small-diameter copper particles) is 0.1 μm or more, 0.15 μm or more, or 0.2 μm from the viewpoint of dispersibility and cost. That may be the above. The maximum diameter of the small-diameter copper particles may be 2.0 μm or less, 1.5 μm or less, or 1.2 μm or less from the viewpoint of sufficient sinterability. The maximum diameter of the small-diameter copper particles is a value measured in the same manner as the maximum diameter of the large-diameter copper particles.
　小径銅粒子の最小径（小径銅粒子の中で最小の粒子径を有する銅粒子の当該粒子径）は、分散性及びコストの観点から、０．０４μｍ以上、０．０６μｍ以上、又は０．１μｍ以上であってよい。小径銅粒子の最小径は、最大径と同様にして測定される。 The minimum diameter of the small-diameter copper particles (the particle size of the copper particles having the smallest particle diameter among the small-diameter copper particles) is 0.04 μm or more, 0.06 μm or more, or 0.1 μm from the viewpoint of dispersibility and cost. That may be the above. The minimum diameter of the small diameter copper particles is measured in the same manner as the maximum diameter.
　小径銅粒子の形状は、例えば、球状、塊状、針状、フレーク状、樹枝状、略球状等であってよい。小径銅粒子は、これらの形状を有する銅粒子の凝集体であってもよい。分散性及び充填性の観点から、小径銅粒子の形状は、球状、略球状、フレーク状であってよい。燃焼性の観点、及び、大径銅粒子が上記不定形である場合に大径銅粒子との混合性が良好となる観点から、小径銅粒子の形状は、球状又は略球状であってよい。 The shape of the small-diameter copper particles may be, for example, spherical, lumpy, needle-like, flake-like, dendritic, substantially spherical, or the like. The small-diameter copper particles may be agglomerates of copper particles having these shapes. From the viewpoint of dispersibility and filling property, the shape of the small-diameter copper particles may be spherical, substantially spherical, or flaky. The shape of the small-diameter copper particles may be spherical or substantially spherical from the viewpoint of flammability and from the viewpoint of good mixing with the large-diameter copper particles when the large-diameter copper particles have the above amorphous shape.
　小径銅粒子の含有量は、焼結体の接着力及び形状保持力に優れる観点から、銅粒子の全質量を基準として、１０質量％以上、１５質量％以上又は２０質量％以上であってよい。小径銅粒子の含有量は、空孔率の向上と空孔サイズの制御の観点から、銅粒子の全質量を基準として、６０質量％以下、３０質量％以下、２７質量％以下又は２５質量％以下であってよい。上記観点から、小径銅粒子の含有量は、銅粒子の全質量を基準として、１０～６０質量％、１５～３０質量％又は２０～２７質量％又は２０～２５質量％であってよい。 The content of the small-diameter copper particles may be 10% by mass or more, 15% by mass or more, or 20% by mass or more based on the total mass of the copper particles from the viewpoint of excellent adhesive strength and shape retention of the sintered body. .. The content of the small-diameter copper particles is 60% by mass or less, 30% by mass or less, 27% by mass or less, or 25% by mass based on the total mass of the copper particles from the viewpoint of improving the pore ratio and controlling the pore size. It may be: From the above viewpoint, the content of the small-diameter copper particles may be 10 to 60% by mass, 15 to 30% by mass, 20 to 27% by mass, or 20 to 25% by mass based on the total mass of the copper particles.
　大径銅粒子の含有量に対する小径銅粒子の含有量の質量比（小径銅粒子の含有量／大径銅粒子の含有量）は、焼結体の接着力及び形状保持力に優れる観点から、０．１以上、０．１８以上又は０．２５以上であってよい。上記質量比（小径銅粒子の含有量／大径銅粒子の含有量）は、空孔率の向上と空孔サイズの制御の観点から、１．０以下、０．６以下又は０．４５以下であってよい。上記観点から、上記質量比は、０．１～１．０、０．１８～０．６又は０．２５～０．４５であってよい。 The mass ratio of the content of the small-diameter copper particles to the content of the large-diameter copper particles (content of the small-diameter copper particles / content of the large-diameter copper particles) is from the viewpoint of excellent adhesive strength and shape retention of the sintered body. It may be 0.1 or more, 0.18 or more, or 0.25 or more. The mass ratio (content of small-diameter copper particles / content of large-diameter copper particles) is 1.0 or less, 0.6 or less, or 0.45 or less from the viewpoint of improving the pore ratio and controlling the pore size. May be. From the above viewpoint, the mass ratio may be 0.1 to 1.0, 0.18 to 0.6 or 0.25 to 0.45.
　銅粒子の含有量は、粘度調整が容易となる観点及び印刷性により優れる観点から、銅ペーストの全質量を基準として、７０質量％以上、７５質量％以上又は８０質量％以上であってよい。銅粒子の含有量は、粘度調整が容易となる観点及び印刷性により優れる観点から、銅ペーストの全質量を基準として、９０質量％以下、８８質量％以下又は８５質量％以下であってよい。上記観点から、銅粒子の含有量は、銅ペーストの全質量を基準として、７０～９０質量％、７５～８８質量％又は８０～８５質量％であってよい。 The content of the copper particles may be 70% by mass or more, 75% by mass or more, or 80% by mass or more based on the total mass of the copper paste from the viewpoint of facilitating viscosity adjustment and being superior in printability. The content of the copper particles may be 90% by mass or less, 88% by mass or less, or 85% by mass or less based on the total mass of the copper paste from the viewpoint of facilitating viscosity adjustment and being superior in printability. From the above viewpoint, the content of the copper particles may be 70 to 90% by mass, 75 to 88% by mass, or 80 to 85% by mass based on the total mass of the copper paste.
（熱分解性樹脂）
　熱分解性樹脂としては、焼結温度で分解し残渣なく分解できる熱分解性を備える樹脂を用いてよい。熱分解性樹脂の９５％熱分解温度は、３５０℃以下、３００℃以下又は２５０℃以下であってよい。なお、９５％熱分解温度とは、ＴＧ／ＤＴＡ測定において測定される９５％重量減少温度とする。この温度は、空気のような酸化雰囲気下ではなく、水素、ギ酸等を含む還元雰囲気下又は酸素を除去した不活性ガス雰囲気下において測定される温度である。 (Pyrolytic resin)
As the pyrolytic resin, a resin having thermal decomposability that can be decomposed at the sintering temperature and decomposed without residue may be used. The 95% pyrolysis temperature of the thermally decomposable resin may be 350 ° C. or lower, 300 ° C. or lower, or 250 ° C. or lower. The 95% thermal decomposition temperature is the 95% weight loss temperature measured in the TG / DTA measurement. This temperature is a temperature measured not in an oxidizing atmosphere such as air, but in a reducing atmosphere containing hydrogen, formic acid and the like, or in an inert gas atmosphere from which oxygen has been removed.
　熱分解性樹脂の熱分解後の残渣は少ないほど銅粒子の焼結性が向上する。焼結温度での残渣の量（灰分）は、熱分解前の樹脂質量に対し通常５質量％以下であり、３質量％以下であってよく、より高い焼結性が得られる観点では、２質量％以下であってもよい。熱分解性樹脂の熱分解後の残渣量は、３～５質量％水素含有イナートガス（窒素或いはアルゴン）中で熱分解性樹脂のＴＧ／ＤＴＡにより焼結温度で焼結時間だけ保持した後の重量変化量として測定できる。なお、空気中でのＴＧ／ＤＴＡ測定は酸化分解が進み、残渣量が還元雰囲気での残渣量と比較して少なくなるため好ましくない。 The smaller the residue after thermal decomposition of the thermally decomposable resin, the better the sinterability of the copper particles. The amount of residue (ash content) at the sintering temperature is usually 5% by mass or less and 3% by mass or less with respect to the mass of the resin before thermal decomposition. From the viewpoint of obtaining higher sintering properties, 2 It may be mass% or less. The amount of residue after pyrolysis of the pyrolyzable resin is the weight after holding for the sintering time at the sintering temperature by TG / DTA of the pyrolysis resin in 3 to 5% by mass hydrogen-containing inert gas (nitrogen or argon). It can be measured as the amount of change. It should be noted that TG / DTA measurement in air is not preferable because oxidative decomposition proceeds and the amount of residue is smaller than the amount of residue in the reducing atmosphere.
　熱分解性樹脂は、後述する分散媒に対し溶解性を有していてよい。分散媒への溶解性を有する熱分解性樹脂としては、ポリカルボナート、ポリ（メタ）アクリル酸、ポリ（メタ）アクリル酸エステル、ポリエステル等が挙げられる。これらの中でも、有機溶媒への溶解性、コスト、及び熱分解性の観点から、ポリメタクリル酸エステルを選択してよい。なお、本明細書中、「（メタ）アクリル」とは、アクリル、及び、それに対応するメタクリルの少なくとも一方を意味する。 The pyrolytic resin may have solubility in the dispersion medium described later. Examples of the pyrolytic resin having solubility in the dispersion medium include polycarbonate, poly (meth) acrylic acid, poly (meth) acrylic acid ester, polyester and the like. Among these, a polymethacrylic acid ester may be selected from the viewpoint of solubility in an organic solvent, cost, and thermal decomposability. In addition, in this specification, "(meth) acrylic" means at least one of acrylic and corresponding methacryl.
　熱分解性樹脂の含有量は、印刷し乾燥した後の形状保持力に優れる観点から、銅粒子１００質量部に対して、１質量部以上、２質量部以上又は３質量部以上であってよい。熱分解性樹脂の含有量は、粘度の調整が容易となる観点及び焼結性に優れる観点から、銅粒子１００質量部に対して、２０質量部以下、１５質量部以下又は１２質量部以下であってよい。上記観点から、熱分解性樹脂の含有量は、銅粒子１００質量部に対して、１～２０質量部、２～１５質量部又は３～１２質量部であってよい。 The content of the pyrolytic resin may be 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more with respect to 100 parts by mass of the copper particles from the viewpoint of excellent shape retention after printing and drying. .. The content of the pyrolytic resin is 20 parts by mass or less, 15 parts by mass or less, or 12 parts by mass or less with respect to 100 parts by mass of copper particles from the viewpoint of easy adjustment of viscosity and excellent sinterability. It may be there. From the above viewpoint, the content of the pyrolytic resin may be 1 to 20 parts by mass, 2 to 15 parts by mass, or 3 to 12 parts by mass with respect to 100 parts by mass of the copper particles.
（分散媒）
　分散媒は特に限定されるものではなく、例えば、揮発性のものであってよい。揮発性の分散媒としては、例えば、ペンタノール、ヘキサノール、ヘプタノール、オクタノール、デカノール、エチレングリコール、ジエチレングリコール、プロピレングリコール、ブチレングリコール、α－ターピネオール、ジヒドロターピネオール、イソボルニルシクロヘキサノール（ＭＴＰＨ）等の一価及び多価アルコール類；エチレングリコールブチルエーテル、エチレングリコールフェニルエーテル、ジエチレングリコールメチルエーテル、ジエチレングリコールエチルエーテル、ジエチレングリコールブチルエーテル、ジエチレングリコールイソブチルエーテル、ジエチレングリコールヘキシルエーテル、トリエチレングリコールメチルエーテル、ジエチレングリコールジメチルエーテル、ジエチレングリコールジエチルエーテル、ジエチレングリコールジブチルエーテル、ジエチレングリコールブチルメチルエーテル、ジエチレングリコールイソプロピルメチルエーテル、トリエチレングリコールジメチルエーテル、トリエチレングリコールブチルメチルエーテル、プロピレングリコールプロピルエーテル、ジプロピレングリコールメチルエーテル、ジプロピレングリコールエチルエーテル、ジプロピレングリコールプロピルエーテル、ジプロピレングリコールブチルエーテル、ジプロピレングリコールジメチルエーテル、トリプロピレングリコールメチルエーテル、トリプロピレングリコールジメチルエーテル等のエーテル類；エチレングリコールエチルエーテルアセテート、エチレングリコールブチルエーテルアセテート、ジエチレングリコールエチルエーテルアセテート、ジエチレングリコールブチルエーテルアセテート、ジプロピレングリコールメチルエーテルアセテート（ＤＰＭＡ）、乳酸エチル、乳酸ブチル、γ－ブチロラクトン、炭酸プロピレン等のエステル類；Ｎ－メチル－２－ピロリドン、Ｎ，Ｎ－ジメチルアセトアミド、Ｎ，Ｎ－ジメチルホルムアミド等の酸アミド；シクロヘキサン、オクタン、ノナン、デカン、ウンデカン等の脂肪族炭化水素；ベンゼン、トルエン、キシレン等の芳香族炭化水素；炭素数１～１８のアルキル基を有するメルカプタン類；炭素数５～７のシクロアルキル基を有するメルカプタン類などが挙げられる。炭素数１～１８のアルキル基を有するメルカプタン類としては、例えば、エチルメルカプタン、ｎ－プロピルメルカプタン、ｉ－プロピルメルカプタン、ｎ－ブチルメルカプタン、ｉ－ブチルメルカプタン、ｔ－ブチルメルカプタン、ペンチルメルカプタン、ヘキシルメルカプタン及びドデシルメルカプタンが挙げられる。炭素数５～７のシクロアルキル基を有するメルカプタン類としては、例えば、シクロペンチルメルカプタン、シクロヘキシルメルカプタン及びシクロヘプチルメルカプタンが挙げられる。 (Dispersion medium)
The dispersion medium is not particularly limited and may be, for example, volatile. Examples of the volatile dispersion medium include pentanol, hexanol, heptanol, octanol, decanol, ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, α-terpineol, dihydroterpineol, and isobornylcyclohexanol (MTPH). Valuable and polyhydric alcohols; ethylene glycol butyl ether, ethylene glycol phenyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, diethylene glycol isobutyl ether, diethylene glycol hexyl ether, triethylene glycol methyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di Butyl ether, diethylene glycol butyl methyl ether, diethylene glycol isopropyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, propylene glycol propyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol propyl ether, dipropylene glycol Ethers such as butyl ether, dipropylene glycol dimethyl ether, tripropylene glycol methyl ether, tripropylene glycol dimethyl ether; ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, dipropylene glycol methyl ether acetate (DPMA) ), Ethers such as ethyl lactate, butyl lactate, γ-butyrolactone, propylene carbonate; acid amides such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide; cyclohexane, octane, nonane , Decane, undecane and other aliphatic hydrocarbons; benzene, toluene, xylene and other aromatic hydrocarbons; mercaptans having an alkyl group having 1 to 18 carbon atoms; mercaptans having a cycloalkyl group having 5 to 7 carbon atoms, etc. Can be mentioned. Examples of mercaptans having an alkyl group having 1 to 18 carbon atoms include ethyl mercaptan, n-propyl mercaptan, i-propyl mercaptan, n-butyl mercaptan, i-butyl mercaptan, t-butyl mercaptan, pentyl mercaptan, and hexyl mercaptan. And dodecyl mercaptan. Examples of mercaptans having a cycloalkyl group having 5 to 7 carbon atoms include cyclopentyl mercaptan, cyclohexyl mercaptan and cycloheptyl mercaptan.
　分散媒の含有量は、銅粒子１００質量部に対して、例えば５～５０質量部であってよい。分散媒の含有量が上記範囲内であれば、銅ペーストをより適切な粘度に調整でき、また、銅粒子の焼結を阻害しにくい。 The content of the dispersion medium may be, for example, 5 to 50 parts by mass with respect to 100 parts by mass of the copper particles. When the content of the dispersion medium is within the above range, the copper paste can be adjusted to a more appropriate viscosity, and the sintering of copper particles is less likely to be hindered.
（その他）
　銅ペーストは、銅粒子以外のその他の金属粒子を更に含んでいてもよい。その他の金属粒子としては、例えば、ニッケル、銀、金、パラジウム、白金等の粒子が挙げられる。その他の金属粒子の含有量は、銅ペーストに含まれる金属粒子の全質量を基準として、０質量％であってよく、０質量％以上２０質量％未満であってもよく、０～１０質量％であってもよく、０～５質量％であってもよい。なお、銅ペーストがその他の金属粒子を含む場合、本明細書中、銅粒子１００質量部に対する含有量は、金属粒子１００質量部に対する含有量と読み替えてよく、銅粒子の全質量を基準とする含有量は、金属粒子の全質量を基準とする含有量と読み替えてよい。 (others)
The copper paste may further contain other metal particles other than the copper particles. Examples of other metal particles include particles such as nickel, silver, gold, palladium, and platinum. The content of the other metal particles may be 0% by mass, 0% by mass or more and less than 20% by mass, and 0 to 10% by mass, based on the total mass of the metal particles contained in the copper paste. It may be 0 to 5% by mass. When the copper paste contains other metal particles, the content with respect to 100 parts by mass of the copper particles may be read as the content with respect to 100 parts by mass of the metal particles in the present specification, and is based on the total mass of the copper particles. The content may be read as the content based on the total mass of the metal particles.
　銅ペーストには、必要に応じて、有機酸（例えばラウリン酸）、有機アミン等の分散性向上剤、ノニオン系界面活性剤、フッ素系界面活性剤等の濡れ向上剤；シリコーン油等の消泡剤；無機イオン交換体等のイオントラップ剤などを適宜添加してもよい。 For the copper paste, if necessary, dispersibility improvers such as organic acids (for example, lauric acid) and organic amines, wetting improvers such as nonionic surfactants and fluorine-based surfactants; defoaming of silicone oil and the like. Agent: An ion trapping agent such as an inorganic ion exchanger may be appropriately added.
　銅ペーストの粘度は、印刷性の観点から、１０～１２０Ｐａ・ｓであってよい。なお、上記粘度は、Ｅ型粘度計により２５℃で回転数２．５ｒｐｍの条件で測定される値である。Ｅ型粘度計として、例えば東機産業株式会社製、製品名：ＶＩＳＣＯＭＥＴＥＲ－ＴＶ３３型粘度計を用いることができる。コーンロータの測定用冶具として、例えば、３°×Ｒ１４、ＳＰＰを適用できる。 The viscosity of the copper paste may be 10 to 120 Pa · s from the viewpoint of printability. The viscosity is a value measured by an E-type viscometer at 25 ° C. and a rotation speed of 2.5 rpm. As the E-type viscometer, for example, a product name: VISCOMETER-TV33 type viscometer manufactured by Toki Sangyo Co., Ltd. can be used. As a jig for measuring the cone rotor, for example, 3 ° × R14, SPP can be applied.
　銅ペーストのチキソトロピーインデックス（以下、ＴＩ値ともいう）は、２．０～２０であってよく、３．０～１５であってもよく、４．０～１０であってもよい。銅ペーストのＴＩ値が上記範囲内にあると、せん断力によって銅ペーストが低粘度化しやすいため、印刷前に手作業又は攪拌装置（例えば、自転公転型攪拌装置（Ｐｌａｎｅｔａｒｙ　Ｖａｃｕｕｍ　Ｍｉｘｅｒ　ＡＲＶ－３１０、株式会社シンキー製）等）により攪拌することで印刷しやすくなる。また、銅ペーストが被着体である部材に付着後、静置によって粘度が回復しやすくなるため、印刷物の過度な濡れ広がりを抑えることができる。なお、ＴＩ値は、Ｅ型粘度計を用いて、２５℃で回転数０．５ｒｐｍの条件で測定された粘度μ０．５と、２５℃で回転数５ｒｐｍの条件で測定される粘度μ５とを用いて、次式で算出される値である。
　ＴＩ値＝μ０．５／μ５ The thixotropy index (hereinafter, also referred to as TI value) of the copper paste may be 2.0 to 20, 3.0 to 15, or 4.0 to 10. If the TI value of the copper paste is within the above range, the viscosity of the copper paste tends to decrease due to the shearing force. It becomes easier to print by stirring with (manufactured by company Shinky) etc.). In addition, after the copper paste adheres to the member to be adhered, the viscosity can be easily recovered by standing, so that excessive wetting and spreading of the printed matter can be suppressed. Incidentally, TI value, using an E-type viscometer, and viscosities mu 0.5 measured at a rotational speed of 0.5rpm at 25 ° C., the viscosity is measured at a rotational speed 5rpm at 25 ° C. mu 5 It is a value calculated by the following equation using and.
TI value = μ 0.5 / μ 5
　上述した銅ペーストは、大径銅粒子と、小径銅粒子と、熱分解性樹脂と、分散媒と、その他の成分とを混合して調製することができる。銅ペーストは、例えば、熱分解性樹脂を分散媒に溶解させた後、大径銅粒子及び小径銅粒子を添加し分散処理を行うことで調製してよく、熱分解性樹脂を分散媒に溶解させて得られる溶液と、大径銅粒子及び小径銅粒子を分散媒に混合し分散処理して得られる分散液と、を混合して調製してもよい。各成分の混合後に、攪拌処理を行ってもよい。分級操作により分散液の最大径を調整してもよい。 The above-mentioned copper paste can be prepared by mixing large-diameter copper particles, small-diameter copper particles, a pyrolytic resin, a dispersion medium, and other components. The copper paste may be prepared, for example, by dissolving a thermally decomposable resin in a dispersion medium and then adding large-diameter copper particles and small-diameter copper particles to perform a dispersion treatment, and the thermally decomposable resin is dissolved in the dispersion medium. The solution obtained by mixing the large-diameter copper particles and the small-diameter copper particles with the dispersion medium and the dispersion liquid obtained by the dispersion treatment may be mixed and prepared. After mixing each component, stirring treatment may be performed. The maximum diameter of the dispersion may be adjusted by a classification operation.
　分散処理は、分散機又は攪拌機を用いて行うことができる。分散処理で使用できる分散機及び攪拌機としては、例えば、石川式攪拌機、シルバーソン攪拌機、キャビテーション攪拌機、自転公転型攪拌装置、超薄膜高速回転式分散機、超音波分散機、ライカイ機、二軸混練機、ビーズミル、ボールミル、三本ロールミル、ホモミキサー、プラネタリーミキサー、超高圧型分散機及び薄層せん断分散機が挙げられる。 The dispersion treatment can be performed using a disperser or a stirrer. Examples of the disperser and stirrer that can be used in the dispersion treatment include Ishikawa stirrer, Silberson stirrer, cavitation stirrer, rotation and revolution type stirrer, ultrathin high-speed rotary disperser, ultrasonic disperser, Raikai machine, and biaxial kneading. Machines, bead mills, ball mills, three-roll mills, homomixers, planetary mixers, ultra-high pressure dispersers and thin layer shear dispersers can be mentioned.
　攪拌処理は、攪拌機を用いて行うことができる。攪拌処理で使用できる攪拌機としては、例えば、石川式攪拌機、自転公転型攪拌装置、ライカイ機、二軸混練機、三本ロールミル及びプラネタリーミキサーが挙げられる。 The stirring process can be performed using a stirrer. Examples of the stirrer that can be used in the stirring process include an Ishikawa type stirrer, a rotation / revolution type stirrer, a Raikai machine, a twin-screw kneader, a three-roll mill and a planetary mixer.
　分級操作は、例えば、ろ過、自然沈降、遠心分離等を用いて行うことができる。ろ過用のフィルタとしては、例えば、水櫛、金属メッシュ、メタルフィルター及びナイロンメッシュが挙げられる。 The classification operation can be performed using, for example, filtration, natural sedimentation, centrifugation, or the like. Examples of the filter for filtration include a water comb, a metal mesh, a metal filter and a nylon mesh.
＜ウィックの形成方法＞
　一実施形態のウィックの形成方法は、銅ペーストを印刷する工程と、当該銅ペーストを焼結させる工程と、を備える。この方法では、上記実施形態の銅ペーストを用いることができる。銅ペーストが焼結することで、銅ペーストの焼結体を含むウィックが得られる。 <How to form a wick>
The wick forming method of one embodiment includes a step of printing a copper paste and a step of sintering the copper paste. In this method, the copper paste of the above embodiment can be used. By sintering the copper paste, a wick containing a sintered body of the copper paste can be obtained.
　銅ペーストの印刷方法は、特に限定されない。例えば、スクリーン印刷、転写印刷、オフセット印刷、ジェットプリンティング法、ディスペンサ、ジェットディスペンサ、ニードルディスペンサ、カンマコータ、スリットコータ、ダイコータ、グラビアコータ、スリットコート、凸版印刷、凹版印刷、グラビア印刷、ステンシル印刷、ソフトリソグラフ、バーコート、アプリケータ、粒子堆積法、スプレーコータ、スピンコータ、ディップコータ、電着塗装等を用いて銅ペーストを印刷することができる。 The printing method of copper paste is not particularly limited. For example, screen printing, transfer printing, offset printing, jet printing method, dispenser, jet dispenser, needle dispenser, comma coater, slit coater, die coater, gravure coater, slit coat, letterpress printing, concave printing, gravure printing, stencil printing, soft lithograph. , Barcoats, applicators, particle deposition methods, spray coaters, spin coaters, dip coaters, electrodeposition coatings and the like can be used to print copper pastes.
　銅ペーストの焼結方法は、特に限定されない。例えば、ホットプレート、温風乾燥機、温風加熱炉、窒素乾燥機、赤外線乾燥機、赤外線加熱炉、遠赤外線加熱炉、マイクロ波加熱装置、レーザー加熱装置、電磁加熱装置、ヒーター加熱装置、蒸気加熱炉等を用いて銅ペーストを加熱処理（焼成）することにより、銅ペーストを焼結させることができる。 The method of sintering the copper paste is not particularly limited. For example, hot plate, hot air dryer, hot air heating furnace, nitrogen dryer, infrared dryer, infrared heating furnace, far infrared heating furnace, microwave heating device, laser heating device, electromagnetic heating device, heater heating device, steam The copper paste can be sintered by heat-treating (baking) the copper paste using a heating furnace or the like.
　加熱処理時のガス雰囲気は、得られる焼結体の酸化を抑制する観点から、無酸素雰囲気であってよい。加熱処理時のガス雰囲気は、銅ペースト中の銅粒子の表面酸化物を除去する観点から、還元雰囲気であってもよい。無酸素雰囲気としては、例えば、窒素、希ガス等の雰囲気、真空雰囲気などが挙げられる。還元雰囲気としては、例えば、純水素ガス雰囲気、フォーミングガスに代表される水素及び窒素の混合ガス雰囲気、ギ酸ガスを含む窒素雰囲気、水素及び希ガスの混合ガス雰囲気、ギ酸ガスを含む希ガス雰囲気等が挙げられる。 The gas atmosphere during the heat treatment may be an oxygen-free atmosphere from the viewpoint of suppressing the oxidation of the obtained sintered body. The gas atmosphere during the heat treatment may be a reducing atmosphere from the viewpoint of removing the surface oxides of the copper particles in the copper paste. Examples of the oxygen-free atmosphere include an atmosphere of nitrogen, a rare gas, and a vacuum atmosphere. Examples of the reducing atmosphere include a pure hydrogen gas atmosphere, a mixed gas atmosphere of hydrogen and nitrogen typified by forming gas, a nitrogen atmosphere containing formic acid gas, a mixed gas atmosphere of hydrogen and rare gas, a rare gas atmosphere containing formic acid gas, and the like. Can be mentioned.
　加熱処理時の到達最高温度は、各部材への熱ダメージの低減及び歩留まりを向上させる観点から、１５０～７００℃であってよく、２００～６００℃であってもよく、２５０～５５０℃であってもよい。到達最高温度が、１５０℃以上であれば、到達最高温度保持時間が６０分間以下において焼結が充分に進行する傾向にある。 The maximum temperature reached during the heat treatment may be 150 to 700 ° C., 200 to 600 ° C., or 250 to 550 ° C. from the viewpoint of reducing heat damage to each member and improving the yield. You may. When the maximum ultimate temperature is 150 ° C. or higher, sintering tends to proceed sufficiently when the maximum ultimate temperature holding time is 60 minutes or less.
　到達最高温度保持時間は、分散媒を全て揮発させる観点、及び、歩留まりを向上させる観点から、１～６０分間であってもよく、１分間以上４０分間未満であってもよく、１分間以上３０分間未満であってもよい。 The maximum temperature retention time may be 1 to 60 minutes, 1 minute or more and less than 40 minutes, or 1 minute or more and 30 minutes or more from the viewpoint of volatilizing all the dispersion medium and improving the yield. It may be less than a minute.
　上記ウィックの形成方法は、銅ペーストを焼結させる工程の前に、銅ペーストを乾燥させる工程を更に備えていてよい。乾燥時のガス雰囲気は大気中であってよく、窒素、希ガス等の無酸素雰囲気中であってもよく、水素、ギ酸等の還元雰囲気中であってもよい。乾燥方法は、常温放置による乾燥であってもよく、加熱乾燥であってもよく、減圧乾燥であってもよい。加熱乾燥及び減圧乾燥には、例えば、ホットプレート、温風乾燥機、温風加熱炉、窒素乾燥機、赤外線乾燥機、赤外線加熱炉、遠赤外線加熱炉、マイクロ波加熱装置、レーザー加熱装置、電磁加熱装置、ヒーター加熱装置、蒸気加熱炉、熱板プレス装置等を用いることができる。乾燥の条件（温度及び時間）は、使用した分散媒の種類及び量に合わせて適宜調整してよい。乾燥の条件（温度及び時間）は、例えば、５０～１８０℃で１～１２０分間乾燥させる条件であってよい。 The wick forming method may further include a step of drying the copper paste before the step of sintering the copper paste. The gas atmosphere at the time of drying may be in the atmosphere, an oxygen-free atmosphere such as nitrogen or a rare gas, or a reducing atmosphere such as hydrogen or formic acid. The drying method may be drying by leaving at room temperature, heat drying, or vacuum drying. Heat drying and vacuum drying include, for example, hot plates, hot air dryers, hot air heating furnaces, nitrogen dryers, infrared dryers, infrared heating furnaces, far infrared heating furnaces, microwave heating devices, laser heating devices, electromagnetic waves. A heating device, a heater heating device, a steam heating furnace, a hot plate pressing device, or the like can be used. The drying conditions (temperature and time) may be appropriately adjusted according to the type and amount of the dispersion medium used. The drying conditions (temperature and time) may be, for example, conditions for drying at 50 to 180 ° C. for 1 to 120 minutes.
　以上で説明したウィックの形成方法によれば、銅ペーストを用いて、印刷によりウィックを形成するため、ウィックの形成面が複雑な形状（例えば凹凸形状、湾曲形状、Ｖ字状の凹部を有する形状等）を有する場合であっても、簡便にウィックを形成することができる。また、上記方法では、銅粒子が大径銅粒子と小径銅粒子とを含むため、焼結時に加圧を行わなくとも充分な焼結性及び形状保持性が得られる。そのため、上記方法では、従来の加圧を必要とする方法と比較して、高い生産性が得られる。また、上記方法では、形成可能なウィックの形状の自由度が高いため、例えば、より薄膜のウィックを形成することが可能となり、また、より複雑な形状（例えば曲線部分を有する形状）のウィックを形成することが容易となる。 According to the wick forming method described above, since the wick is formed by printing using copper paste, the wick forming surface has a complicated shape (for example, a concave-convex shape, a curved shape, and a shape having a V-shaped concave portion). Etc.), the wick can be easily formed. Further, in the above method, since the copper particles contain large-diameter copper particles and small-diameter copper particles, sufficient sinterability and shape retention can be obtained without applying pressure during sintering. Therefore, the above method can obtain high productivity as compared with the conventional method requiring pressurization. Further, in the above method, since the degree of freedom in the shape of the wick that can be formed is high, for example, a wick having a thinner film can be formed, and a wick having a more complicated shape (for example, a shape having a curved portion) can be formed. It becomes easy to form.
＜ヒートパイプ＞
　一実施形態のヒートパイプは、上記実施形態の銅ペーストの焼結体を含むウィックを備える。ウィックを除くヒートパイプの構成は、従来公知のヒートパイプ（ベーパーチャンバー等）と同様の構成とすることができる。銅ペーストの焼結体を含むウィックは、上記実施形態のウィックの形成方法に従って形成することができる。すなわち、ヒートパイプの製造方法は、ウィックの形成工程を除き、従来公知のヒートパイプと同様の方法で製造することができる。以下、図面を参照しつつ、ヒートパイプの一例について説明する。 <Heat pipe>
The heat pipe of one embodiment includes a wick containing a sintered body of the copper paste of the above embodiment. The structure of the heat pipe excluding the wick can be the same as that of a conventionally known heat pipe (vapor chamber or the like). The wick containing the sintered body of the copper paste can be formed according to the wick forming method of the above embodiment. That is, the heat pipe can be manufactured by the same method as the conventionally known heat pipe except for the wick forming step. Hereinafter, an example of a heat pipe will be described with reference to the drawings.
　図１は、一実施形態のヒートパイプを示す模式断面図である。ヒートパイプ１は、密閉空間Ｓを画定するコンテナ２と、コンテナ２の空間Ｓに収容されたウィック３及び作動液体と、を備える。コンテナ２によって画定される空間Ｓには、熱源により気化した作動液体の気化物が流通可能となるように気相空間Ａが確保されている。図示していないが、作動液体は、例えば、水又は有機溶媒であり、ウィック３に含浸されている。 FIG. 1 is a schematic cross-sectional view showing a heat pipe of one embodiment. The heat pipe 1 includes a container 2 that defines a closed space S, a wick 3 housed in the space S of the container 2, and a working liquid. In the space S defined by the container 2, a gas phase space A is secured so that the vaporized product of the working liquid vaporized by the heat source can flow. Although not shown, the working liquid is, for example, water or an organic solvent and is impregnated in Wick 3.
　コンテナ２の形状は特に限定されず、管状、平板状等であってよい。コンテナ２の形状が平板状である場合、例えば、以下の方法でヒートパイプを形成してよい。まず、表面に凹部が形成された第一の基材の当該凹部に銅ペーストを印刷してウィックを形成する。次いで、第一の基材と、表面に凹部が形成された第二の基材とを、互いの凹部が対向するように貼り合わせる。これにより、平板状のコンテナ２を備えるヒートパイプ１が得られる。 The shape of the container 2 is not particularly limited, and may be tubular, flat plate, or the like. When the shape of the container 2 is flat, for example, a heat pipe may be formed by the following method. First, a copper paste is printed on the recesses of the first base material having recesses formed on the surface to form a wick. Next, the first base material and the second base material having recesses formed on the surface are bonded to each other so that the recesses face each other. As a result, the heat pipe 1 including the flat plate-shaped container 2 can be obtained.
　コンテナ２の材質は、熱伝導率、耐圧性、ガス遮蔽性、加工性等の観点から、金属であってよい。金属としては、例えば、銅、銅合金、アルミニウム、ステンレス鋼、炭素鋼等が用いられる。 The material of the container 2 may be metal from the viewpoints of thermal conductivity, pressure resistance, gas shielding property, workability, and the like. As the metal, for example, copper, copper alloy, aluminum, stainless steel, carbon steel and the like are used.
　ウィック３は、コンテナ２の内壁面に配置されている。ウィック３は、上記実施形態の銅ペーストを焼結してなる多孔質体である。したがって、ウィック３は、上記実施形態の銅ペーストの焼結体を含んでいる。ウィック３は、コンテナ２と一体形成されていてよく、予め形成されたもの（別途配置されたもの）であってもよい。 The wick 3 is arranged on the inner wall surface of the container 2. Wick 3 is a porous body obtained by sintering the copper paste of the above embodiment. Therefore, the wick 3 contains a sintered body of the copper paste of the above embodiment. The wick 3 may be integrally formed with the container 2, or may be a preformed one (separately arranged one).
　ウィック３の空孔率（焼結体の空孔率）は、毛管現象による作動液体の流通しやすさの観点から、ウィックの体積を基準として、４０体積％以上、４５体積％以上又は５０体積％以上であってよい。ウィック３の空孔率（焼結体の空孔率）は、特に限定されないが、例えば、ウィックの体積を基準として、９０体積％以下又は８０体積％以下であってよい。すなわち、ウィック３の空孔率（焼結体の空孔率）は、例えば、ウィックの体積を基準として、４０～８０体積％、４５～８０体積％又は５０～８０体積％であってよい。空孔率は、走査型電子顕微鏡、走査型イオン顕微鏡等によって観察したウィックの断面画像を、画像解析ソフトを用いて解析することにより得られる。また、ウィックを構成する金属材料の組成が分かっている場合には、ウィックの体積と、ウィック中の金属の体積との差から求めることもできる。金属の体積は、例えば、ウィックの体積と、精密天秤で測定したウィックの重量とから見かけの密度Ｍ１（ｇ／ｃｍ３）を求め、求めたＭ１と、金属の密度（例えば銅の密度８．９６ｇ／ｃｍ３）とを用いて、下記式（Ａ）から体積割合を求めることで得られる。
金属の体積割合（体積％）＝［（Ｍ１）／（金属の密度）］×１００…（Ａ） The porosity of the wick 3 (porosity of the sintered body) is 40% by volume or more, 45% by volume or more, or 50% by volume based on the volume of the wick from the viewpoint of ease of circulation of the working liquid due to the capillary phenomenon. It may be% or more. The porosity of the wick 3 (porosity of the sintered body) is not particularly limited, but may be, for example, 90% by volume or less or 80% by volume or less based on the volume of the wick. That is, the porosity of the wick 3 (porosity of the sintered body) may be, for example, 40 to 80% by volume, 45 to 80% by volume, or 50 to 80% by volume based on the volume of the wick. The porosity is obtained by analyzing a cross-sectional image of a wick observed with a scanning electron microscope, a scanning ion microscope, or the like using image analysis software. Further, when the composition of the metal material constituting the wick is known, it can be obtained from the difference between the volume of the wick and the volume of the metal in the wick. For the volume of the metal, for example, the apparent density M 1 (g / cm 3 ) was obtained from the volume of the wick and the weight of the wick measured by a precision balance, and the obtained M 1 and the density of the metal (for example, the density of copper) were obtained. It can be obtained by calculating the volume ratio from the following formula (A) using 8.96 g / cm 3).
Metal volume ratio (volume%) = [(M 1 ) / (metal density)] × 100 ... (A)
　ウィック３の平均空孔径は、流動抵抗と毛管力のバランスが良好となる観点から、１０μｍ以上、１５μｍ以上又は２０μｍ以上であってよい。ウィック３の平均空孔径は、流動抵抗と毛管力のバランスが良好となる観点及びウィックの薄厚化が容易となる観点から、５０μｍ以下、４５μｍ以下又は４０μｍ以下であってよい。上記観点から、ウィック３の平均空孔径は、１０～５０μｍ、１５～４５μｍ又は２０～４０μｍであってよい。平均空孔径は、注形断面加工した断面のＳＥＭ像における空孔部を測長することによって求められる。 The average pore diameter of Wick 3 may be 10 μm or more, 15 μm or more, or 20 μm or more from the viewpoint of improving the balance between flow resistance and capillary force. The average pore diameter of the wick 3 may be 50 μm or less, 45 μm or less, or 40 μm or less from the viewpoint of improving the balance between the flow resistance and the capillary force and facilitating the thinning of the wick. From the above viewpoint, the average pore diameter of the wick 3 may be 10 to 50 μm, 15 to 45 μm, or 20 to 40 μm. The average pore diameter is obtained by measuring the length of the pores in the SEM image of the cross section processed by casting.
　ウィック３は、注形断面加工した断面のＳＥＭ像における空孔部を測長することにより求められる空孔径分布において、２つ以上のピークを有していてよい。具体的には、例えば、０．５～５μｍに第一のピークを有し、１０～５０μｍに第二のピークを有していてよい。このような空孔ピークを有する場合、第一のピークを有する小さな細孔により強い毛管力が得られ、第二のピークを有する大きな空孔により素早く多量の液体輸送が可能となる傾向がある。 The wick 3 may have two or more peaks in the pore size distribution obtained by measuring the length of the pores in the SEM image of the cross section processed by casting. Specifically, for example, it may have a first peak at 0.5 to 5 μm and a second peak at 10 to 50 μm. When having such a pore peak, a strong capillary force is obtained by the small pores having the first peak, and a large amount of liquid can be transported quickly by the large pore having the second peak.
　以上説明したヒートパイプは、例えば、コンテナの外壁に放熱部材が設けられた状態で使用される。ヒートパイプは、例えば、スマートフォン、タブレット等の小型情報機器用の放熱デバイスとして好適に用いられる。 The heat pipe described above is used, for example, with a heat radiating member provided on the outer wall of the container. The heat pipe is suitably used as a heat radiating device for small information devices such as smartphones and tablets.
　以下、本発明の内容を実施例及び比較例を用いてより詳細に説明するが、本発明は以下の実施例に限定されるものではない。 Hereinafter, the content of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.
＜実施例１＞
［銅ペーストの調製］
　分散媒としてジヒドロターピネオール（日本テルペン化学株式会社製）１１．７ｇと、熱分解性樹脂としてＫＦＡ－２０００（アクリル系樹脂のジヒドロターピネオール溶液、固形分量：２４質量％、９５％熱分解温度＝３３０℃、互応化学製）３．０ｇと、添加剤（分散性向上剤）としてラウリン酸０．３ｇとをポリ瓶にいれ、自転公転型攪拌装置（Ｐｌａｎｅｔｒｙ　Ｖａｃｕｕｍ　Ｍｉｘｅｒ　ＡＲＶ－３１０、株式会社シンキー製）で混合した。この分散液に、小径銅粒子としてＣＨ－０２００（三井金属鉱業株式会社製、体積平均粒径：０．３６μｍ）１７．０ｇと、大径銅粒子としてＣｕＡｔＷ－２５０（福田金属箔粉工業製、体積平均粒径：２７μｍ）６８ｇとを添加し、自転公転型攪拌装置（Ｐｌａｎｅｔｒｙ　Ｖａｃｕｕｍ　Ｍｉｘｅｒ　ＡＲＶ－３１０、株式会社シンキー製）を用いて、２０００ｒｐｍで１分間攪拌した。その後、一度全体を薬さじで攪拌して固形物が無いことを確認し、減圧下、２０００ｒｐｍで１分間攪拌して銅ペーストを得た。なお、ＣｕＡｔＷ－２５０は不定形を有しており、タップ密度は３．９ｇ／ｃｍ３であった。また、銅ペーストの粘度は３２Ｐａ・ｓであった。粘度は、ＳＰＰロータを装着したＥ型粘度計（ＶＩＳＣＯＭＥＴＥＲ　ＴＶ－３３　東機産業製）を用い、温度２５℃下、回転数２．５回転／ｍｉｎの条件で測定した。粘度値は、測定開始から１４４秒経過後の粘度値である（ＪＩＳ３２８４）。 <Example 1>
[Preparation of copper paste]
11.7 g of dihydroterpineol (manufactured by Nippon Terupen Chemical Co., Ltd.) as a dispersion medium and KFA-2000 (dihydroterpineol solution of acrylic resin, solid content: 24% by mass, 95% pyrolysis temperature = 330 ° C.) as a pyrolytic resin. , Reciprocal chemicals) 3.0 g and lauric acid 0.3 g as an additive (dispersibility improver) in a plastic bottle, and use a rotating and revolving stirrer (Planetry Vacuum Mixer ARV-310, manufactured by Shinky Co., Ltd.). Mixed. CH-0200 (manufactured by Mitsui Metal Mining Co., Ltd., volume average particle size: 0.36 μm) 17.0 g as small-diameter copper particles and CuAtW-250 (manufactured by Fukuda Metal Foil Powder Industry) as large-diameter copper particles in this dispersion. (Volume average particle size: 27 μm) 68 g was added, and the mixture was stirred at 2000 rpm for 1 minute using a rotation / revolution type stirrer (Planetry Vacuum Mixer ARV-310, manufactured by Shinky Co., Ltd.). Then, the whole was once stirred with a spatula to confirm that there was no solid matter, and the mixture was stirred at 2000 rpm for 1 minute under reduced pressure to obtain a copper paste. CuAtW-250 had an amorphous shape, and the tap density was 3.9 g / cm 3 . The viscosity of the copper paste was 32 Pa · s. The viscosity was measured using an E-type viscometer (VISCOMETER TV-33 manufactured by Toki Sangyo Co., Ltd.) equipped with an SPP rotor under the conditions of a temperature of 25 ° C. and a rotation speed of 2.5 rotations / min. The viscosity value is the viscosity value after 144 seconds have passed from the start of measurement (JIS3284).
＜実施例２～４及び比較例１＞
　大径銅粒子の配合量及び小径銅粒子の配合量を表１に示す量に変更したこと以外は、実施例１と同様にして、銅ペーストを作製した。なお、本実施例において、表に示す配合量（単位：質量部）は固形分量である。 <Examples 2 to 4 and Comparative Example 1>
A copper paste was prepared in the same manner as in Example 1 except that the blending amount of the large-diameter copper particles and the blending amount of the small-diameter copper particles were changed to the amounts shown in Table 1. In this example, the blending amount (unit: parts by mass) shown in the table is the amount of solid content.
＜実施例５＞
　大径銅粒子の配合量、小径銅粒子及びラウリン酸の配合量を表２に示す量に変更したこと、分散媒として、ジヒドロターピネオールに代えてターピネオールＣ（α－，β－，γ－ターピネオールの異性体混合物、日本テルペン化学株式会社製、商品名）を表２に示す量用いたこと、及び、熱分解性樹脂として、ＫＦＡ－２０００に代えて、表２に示す量のＭ－６００３（分子量Ｍｎ＝１８９３００、９５％熱分解温度＝２８４℃、根上工業株式会社製、商品名）の溶液（所定量のターピネオールＣにＭ－６００３を溶解させることにより作製した溶液）を用いたこと以外は、実施例１と同様にして、銅ペーストを作製した。実施例１と同様にして測定した銅ペーストの粘度は、６３Ｐａ・ｓであった。 <Example 5>
The amount of large-diameter copper particles and the amount of small-diameter copper particles and lauric acid were changed to the amounts shown in Table 2. As a dispersion medium, tarpineol C (α-, β-, γ-terpineol) was used instead of dihydrotarpineol. An isomer mixture (manufactured by Nippon Terupen Chemical Co., Ltd., trade name) was used in the amount shown in Table 2, and the amount of M-6003 (molecular weight) shown in Table 2 was used instead of KFA-2000 as the pyrolytic resin. Except for the use of a solution of Mn = 189300, 95% pyrolysis temperature = 284 ° C., manufactured by Negami Kogyo Co., Ltd., trade name) (a solution prepared by dissolving M-6003 in a predetermined amount of tarpineol C). A copper paste was prepared in the same manner as in Example 1. The viscosity of the copper paste measured in the same manner as in Example 1 was 63 Pa · s.
＜実施例６＞
　大径銅粒子の配合量及びラウリン酸の配合量を表２に示す量に変更したこと、小径銅粒子として、ＣＨ－０２００に代えてＣＴ－０５００（三井金属鉱業株式会社製、体積平均粒径：１．１１μｍ）を表２に示す量用いたこと、分散媒として、ジヒドロターピネオールに代えてターピネオールＣ（α－，β－，γ－ターピネオールの異性体混合物、日本テルペン化学株式会社製、商品名）を表２に示す量用いたこと、及び、熱分解性樹脂として、ＫＦＡ－２０００に代えて、表２に示す量のＭ－６００３（分子量Ｍｎ＝１８９３００、９５％分解温度＝２８４℃、根上工業株式会社製、商品名）の溶液（所定量のターピネオールＣにＭ－６００３を溶解させることにより作製した溶液）を用いたこと以外は、実施例１と同様にして、銅ペーストを作製した。 <Example 6>
The amount of large-diameter copper particles and the amount of lauric acid were changed to the amounts shown in Table 2, and as small-diameter copper particles, CT-0500 (manufactured by Mitsui Metal Mining Co., Ltd., volume average particle size) was used instead of CH-0200. : 1.11 μm) was used in the amount shown in Table 2, and as a dispersion medium, tarpineol C (α-, β-, γ-terpineol isomer mixture, manufactured by Nippon Terpen Chemical Co., Ltd., trade name) was used instead of dihydroterpineol. ) Was used in the amount shown in Table 2, and instead of KFA-2000 as the thermally decomposable resin, the amount of M-6003 (molecular weight Mn = 189300, 95% decomposition temperature = 284 ° C., root) shown in Table 2 was used. A copper paste was prepared in the same manner as in Example 1 except that a solution (trade name, manufactured by Kogyo Co., Ltd.) (a solution prepared by dissolving M-6003 in a predetermined amount of tarpineol C) was used.
＜実施例７＞
　分散媒としてターピネオールＣ（α－，β－，γ－ターピネオールの異性体混合物、日本テルペン化学株式会社製、商品名）を１６２．４ｇと、熱分解性樹脂としてＭ－６００３（根上工業製）を２６．６ｇとを混合し、攪拌翼を用いたミックスロータで３時間攪拌し完全に溶解させて樹脂溶液を得た。この樹脂溶液に、小径銅粒子としてＣＴ－０５００（三井金属鉱業株式会社製、体積平均粒径：１．１１μｍ）１６２．０ｇを加え、プラネタリーミキサー（Ｔ．ｋ。ＨＩＶＩＳ　ＭＩＸ　ｆｍｏｄｅｌ．０３、ＰＲＩＭＩＸ製）を用いて、５０ｒｐｍで１５分間混合した。その後、大径銅粒子として、ＣｕＡｔＷ－２５０（福田金属箔粉工業製、体積平均粒径：２７μｍ）５６７ｇと、ＦＣ－１１５（樹状銅粉、福田金属箔粉工業製、体積平均粒径：２１μｍ、タップ密度：１．２ｇ／ｃｍ３）８１ｇとを添加し、プラネタリーミキサーを用いて５０ｒｐｍで１５分間混合した。さらに、減圧して５０ｒｐｍで１５分間混合して銅ペーストを得た。実施例１と同様にして測定した銅ペーストの粘度は、５０Ｐａ・ｓであった。 <Example 7>
162.4 g of tarpineol C (a mixture of α-, β-, γ-terpineol isomers, manufactured by Nippon Terpine Chemical Co., Ltd., trade name) as a dispersion medium, and M-6003 (manufactured by Negami Kogyo) as a pyrolytic resin. 26.6 g was mixed and stirred with a mix rotor using a stirring blade for 3 hours to completely dissolve the mixture to obtain a resin solution. To this resin solution, 162.0 g of CT-0500 (manufactured by Mitsui Mining & Smelting Co., Ltd., volume average particle size: 1.11 μm) was added as small-diameter copper particles, and a planetary mixer (TK HIVIS MIX format.03, PRIMIX) was added. Was mixed at 50 rpm for 15 minutes. After that, as large-diameter copper particles, 567 g of CuAtW-250 (manufactured by Fukuda Metal Foil Powder Industry, volume average particle size: 27 μm) and FC-115 (dendritic copper powder, manufactured by Fukuda Metal Foil Powder Industry, volume average particle size: 21 μm, tap density: 1.2 g / cm 3 ) 81 g was added and mixed at 50 rpm for 15 minutes using a planetary mixer. Further, the pressure was reduced and the mixture was mixed at 50 rpm for 15 minutes to obtain a copper paste. The viscosity of the copper paste measured in the same manner as in Example 1 was 50 Pa · s.
＜比較例２＞
　大径銅粒子、小径銅粒子及びラウリン酸の配合量を表２に示す値に変更したこと、分散媒として、ジヒドロターピネオールに代えてターピネオールＣ（α－，β－，γ－ターピネオールの異性体混合物、日本テルペン化学株式会社製、商品名）を表２に示す量用いたこと、及び、熱分解性樹脂（ＫＦＡ－２０００）を用いなかったこと以外は、実施例１と同様にして、銅ペーストを作製した。 <Comparative example 2>
The blending amounts of large-diameter copper particles, small-diameter copper particles, and lauric acid were changed to the values shown in Table 2, and as a dispersion medium, terpineol C (α-, β-, γ-terpineol isomer mixture) was used instead of dihydroterpineol. , Nippon Terpene Chemical Co., Ltd., trade name) was used in the amounts shown in Table 2, and the copper paste was used in the same manner as in Example 1 except that the pyrolytic resin (KFA-2000) was not used. Was produced.
＜比較例３及び４＞
　大径銅粒子であるＣｕＡｔＷ－２５０（福田金属箔粉工業製、体積平均粒径：２７μｍ）に代えて、ＭＡ－Ｃ２５（三井金属鉱業株式会社製、体積平均粒径：８μｍ）又は１４００ＹＦ（三井金属鉱業株式会社製、体積平均粒径：５μｍ）を用いたこと以外は、実施例６と同様にして、銅ペーストを作製した。 <Comparative Examples 3 and 4>
Instead of CuAtW-250 (manufactured by Fukuda Metal Foil Powder Industry, volume average particle size: 27 μm), which is a large-diameter copper particle, MA-C25 (manufactured by Mitsui Metal Mining Co., Ltd., volume average particle size: 8 μm) or 1400YF (Mitsui) A copper paste was prepared in the same manner as in Example 6 except that a volume average particle size (5 μm) manufactured by Metal Mining Co., Ltd. was used.
＜評価＞
［銅ペーストの印刷性評価（１）］
　ハルセル銅板を３等分し、縦３０ｍｍ×横６７ｍｍ×厚さ３００μｍの銅板を用意した。この銅板上に、２５ｍｍ×５ｍｍの開口が２か所設けられた厚さ７０μｍのＳＵＳマスクを載せ、メタルスキージを用いて銅ペーストを印刷した。この際、擦れ、斑無く均一な厚みの塗布面が得られた場合を印刷性Ａとし、数本の筋状の擦れ及び／又は斑のある塗布面が得られた場合を印刷性Ｂとし、基板が透ける程の擦れ及び／又は斑が塗布面全面に生じている場合を印刷性Ｃとした。印刷性（１）として、結果を表１及び表２に示す。 <Evaluation>
[Evaluation of printability of copper paste (1)]
The Halcel copper plate was divided into three equal parts, and a copper plate having a length of 30 mm, a width of 67 mm, and a thickness of 300 μm was prepared. A 70 μm-thick SUS mask having two 25 mm × 5 mm openings was placed on the copper plate, and a copper paste was printed using a metal squeegee. At this time, the case where a coated surface having a uniform thickness without rubbing and unevenness is obtained is defined as printability A, and the case where several streaky rubbing and / or coated surfaces with spots are obtained is defined as printability B. The case where rubbing and / or unevenness to the extent that the substrate was transparent occurred on the entire surface of the coated surface was defined as printability C. The results are shown in Tables 1 and 2 as the printability (1).
［銅ペーストの印刷性評価（２）］
　銅ペーストを武蔵エンジニアリング株式会社製の５ｍＬプラスチックシリンジに入れた。銅ペーストを入れたシリンジを空圧ディスペンサ（ＭＬ－５０５Ｘ，武蔵エンジニアリング製）にセットし、シリンジの先端に幅広印刷用ニードルを取り付け、１ｋｇｆ／ｃｍ２（＝９８ｋＰａ）の圧力で銅板（ハルセル銅板を３等分したもの、縦３０ｍｍ×横６７ｍｍ×厚さ３００μｍ）上に吐出した。この際、連続的且つ均一に吐出し印刷できた場合を印刷性Ａとし、吐出が間欠的であったり、非常に遅い場合を印刷性Ｂとし、吐出できない、或いは吐出中に吐出が止まった場合を印刷性Ｃとした。印刷性（２）として、結果を表１及び表２に示す。 [Evaluation of printability of copper paste (2)]
The copper paste was placed in a 5 mL plastic syringe manufactured by Musashi Engineering Co., Ltd. Set the syringe containing the copper paste in a pneumatic dispenser (ML-505X, manufactured by Musashi Engineering), attach a wide printing needle to the tip of the syringe, and attach a copper plate (Halcel copper plate) at a pressure of 1 kgf / cm 2 (= 98 kPa). It was divided into three equal parts (length 30 mm × width 67 mm × thickness 300 μm) and discharged. At this time, the case where continuous and uniform ejection printing is possible is defined as printability A, the case where ejection is intermittent or very slow is defined as printability B, and the case where ejection is not possible or the ejection is stopped during ejection. Was designated as printability C. The results are shown in Tables 1 and 2 as printability (2).
［焼結前形状保持性評価］
　実施例及び比較例の銅ペーストを、７０μｍ厚のステンシル版で印刷し、乾燥した。得られた焼結前の印刷物を指で擦ることにより、焼結前の形状保持性を評価した。指でこすっても印刷形状が崩れないものを焼結前形状保持性Ａとし、指でこすると印刷物が粉状に崩れて形状が維持できない場合を焼結前形状保持性Ｃとした。結果を表１及び表２に示す。 [Evaluation of shape retention before sintering]
The copper pastes of Examples and Comparative Examples were printed on a 70 μm thick stencil plate and dried. The shape retention before sintering was evaluated by rubbing the obtained printed matter before sintering with a finger. The case where the printed shape does not collapse even when rubbed with a finger is defined as the pre-sintering shape retention A, and the case where the printed matter collapses into powder and the shape cannot be maintained when rubbed with a finger is defined as the pre-sintering shape retention C. The results are shown in Tables 1 and 2.
［銅ペーストの焼成］
　上記銅ペーストの印刷性評価（１）及び（２）で得られた銅ペーストが印刷された銅板を、９０℃に加熱したホットプレート上に載せ、空気中で１０分間乾燥し、焼成サンプルとした。管状炉（株式会社エイブイシー製）のガラストレー上にサンプルを載せ、管状炉にセットした。減圧後、水素１００ｓｃｃｍ及び窒素９００ｓｃｃｍを流し、常圧に戻ったところで、６００℃、昇温２０分間、保持６０分間の条件で焼成した。その後、ガスを停止し、減圧しながら強制空冷して３０分間以上冷却した。アルゴンガスで常圧に戻した後、焼成後のサンプルを空気中に取り出した。これにより、銅ペーストの焼結体を得た。以下の評価では、印刷性評価（１）で得られた銅ペーストを用いて得られたサンプル（焼結体）を用いた。 [Baking copper paste]
Evaluation of Printability of Copper Paste The copper plate on which the copper paste obtained in (1) and (2) was printed was placed on a hot plate heated to 90 ° C. and dried in air for 10 minutes to prepare a baking sample. .. The sample was placed on a glass tray of a tube furnace (manufactured by ABC Co., Ltd.) and set in the tube furnace. After depressurization, 100 sccm of hydrogen and 900 sccm of nitrogen were flowed, and when the pressure was returned to normal pressure, firing was performed under the conditions of 600 ° C., temperature rise for 20 minutes, and retention for 60 minutes. Then, the gas was stopped, forced air cooling was performed while reducing the pressure, and the mixture was cooled for 30 minutes or more. After returning to normal pressure with argon gas, the fired sample was taken out into the air. As a result, a sintered body of copper paste was obtained. In the following evaluation, a sample (sintered body) obtained by using the copper paste obtained in the printability evaluation (1) was used.
［密着性評価（テープ剥離試験）］
　上記で得られた焼結体上にニチバン株式会社製の幅１６ｍｍのセロテープ（登録商標）を貼り付け、約１０秒間指先でしっかりとテープをこすった。その後、３０秒間以上５分間以内に、できるだけ６０°に近い角度でテープの端をつかみ、０．５～１．０秒間で引きはがし、テープへの付着物を確認した。付着物が無い場合をＡ、部分的に小量の付着物がある場合をＢ、全面に付着物が生じた場合をＣと判定した。結果を表１及び表２に示す。 [Adhesion evaluation (tape peeling test)]
A 16 mm wide cellophane tape (registered trademark) manufactured by Nichiban Co., Ltd. was attached onto the sintered body obtained above, and the tape was rubbed firmly with a fingertip for about 10 seconds. Then, within 30 seconds or more and 5 minutes or less, the edge of the tape was grasped at an angle as close to 60 ° as possible, and the tape was peeled off in 0.5 to 1.0 seconds to confirm adhesion to the tape. The case where there was no deposit was determined as A, the case where there was a small amount of deposit was determined as B, and the case where the deposit was formed on the entire surface was determined as C. The results are shown in Tables 1 and 2.
［空孔率の測定］
　上記で得られたサンプルをプラスチックカップに入れて注形樹脂（エポマウント、リファインテック株式会社製）を流し込み、真空デシケータ内に静置し、減圧して脱泡した。その後、室温下で１０時間放置して注形樹脂を硬化させた。レジノイド砥石をつけたリファインソー・エクセル（リファインテック株式会社製）を用い、注形したサンプルの観察したい断面付近で切断した。耐水研磨紙（カーボマックペーパー、リファインテック株式会社製）をつけた研磨装置（Ｒｅｆｉｎｅ　Ｐｏｌｉｓｈｅｒ　Ｈｖ、リファインテック株式会社製）で断面を削り、アルミナ研磨液を用いてバフ研磨をした。このサンプルをＳＥＭ　装置（ＴＭ－１０００、株式会社日立ハイテクノロジーズ製）により、印加電圧１５ｋＶ、各種倍率で観察した。観察像をＩｍａｇｅ　Ｊ　により二値化し、白色部と黒色部のドット数比から焼結体（ウィック）の空孔率（単位：体積％）を求めた。結果を表１及び表２に示す。 [Measurement of porosity]
The sample obtained above was placed in a plastic cup, cast resin (Epomount, manufactured by Refine Tech Co., Ltd.) was poured, and the mixture was allowed to stand in a vacuum desiccator and defoamed by reducing the pressure. Then, the casting resin was cured by leaving it at room temperature for 10 hours. Using a refine saw Excel (manufactured by Refine Tech Co., Ltd.) equipped with a resinoid grindstone, the cast sample was cut near the cross section to be observed. The cross section was ground with a polishing device (Refine Polisher Hv, manufactured by Refine Tech Co., Ltd.) equipped with water-resistant polishing paper (Carbomac Paper, manufactured by Refine Tech Co., Ltd.), and buffing was performed using an alumina polishing liquid. This sample was observed with an SEM device (TM-1000, manufactured by Hitachi High-Technologies Corporation) at an applied voltage of 15 kV and various magnifications. The observed image was binarized by Image J, and the porosity (unit: volume%) of the sintered body (wick) was obtained from the ratio of the number of dots in the white part and the black part. The results are shown in Tables 1 and 2.
［平均空孔径の測定］
　上記［空孔率の測定］で取得した５００倍のＳＥＭ像の空孔をＩｍａｇｅ　Ｊ　により測長し、２０箇所の平均により、焼結体（ウィック）の平均空孔径を求めた。結果を表１及び表２に示す。 [Measurement of average pore diameter]
The pores of the 500-fold SEM image obtained in the above [Measurement of porosity] were measured by Image J, and the average pore diameter of the sintered body (wick) was determined by averaging 20 points. The results are shown in Tables 1 and 2.
［空孔径分布の測定］
　上記［空孔率の測定］で取得した５００倍のＳＥＭ像及び１００００倍のＳＥＭ像を各３画像用い、当該画像に写った空孔をＩｍａｇｅ　Ｊ　により測長し、１２０箇所のサイズ分布により、焼結体（ウィック）の空孔径分布を求めた。図２に、実施例７のＳＥＭ画像を示す。図２の（ａ）は５００倍のＳＥＭ画像であり、図２の（ｂ）は１００００倍のＳＥＭ画像である。実施例１では、１．２μｍと２０μｍに空孔径ピークを有することを確認した。実施例６では、１．０μｍと３０μｍに空孔径ピークを有することを確認した。実施例７では、１．１μｍと３０μｍに空孔径ピークを有することを確認した。 [Measurement of pore size distribution]
Using 3 images each of 500 times SEM image and 10000 times SEM image acquired in the above [Measurement of porosity], the holes in the images were measured by Image J, and the size distribution at 120 points was used. The porosity distribution of the sintered body (wick) was determined. FIG. 2 shows an SEM image of Example 7. FIG. 2A is a 500-fold SEM image, and FIG. 2B is a 10000-fold SEM image. In Example 1, it was confirmed that the pore diameter peaks were at 1.2 μm and 20 μm. In Example 6, it was confirmed that the pore diameter peaks were present at 1.0 μm and 30 μm. In Example 7, it was confirmed that the pore diameter peaks were at 1.1 μm and 30 μm.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
［ウィックの作製］
　実施例の銅ペーストを用いて作製した焼結体については、得られた焼結体を用いてヒートパイプを構成し、焼結体がウィックとして機能することを確認した。一方、比較例１の銅ペーストを用いて作製した焼結体は、上記評価結果に示されるとおり、密着性が不充分であり、比較例１の銅ペーストは、ウィック形成用の銅ペーストとしては不適であった。また、比較例２の銅ペーストは印刷性に乏しく、比較例２の銅ペーストでは焼結体を作製できなかった。また、比較例３及び４の銅ペーストを用いて作製した焼結体については、焼結体がウィックとして機能しなかった。 [Making a wick]
Regarding the sintered body produced using the copper paste of the example, a heat pipe was constructed using the obtained sintered body, and it was confirmed that the sintered body functions as a wick. On the other hand, the sintered body produced using the copper paste of Comparative Example 1 has insufficient adhesion as shown in the above evaluation results, and the copper paste of Comparative Example 1 is suitable as a copper paste for forming a wick. It was unsuitable. Further, the copper paste of Comparative Example 2 was poor in printability, and the copper paste of Comparative Example 2 could not produce a sintered body. Further, in the sintered body prepared by using the copper pastes of Comparative Examples 3 and 4, the sintered body did not function as a wick.
　１…ヒートパイプ、２…コンテナ、３…ウィック。 1 ... heat pipe, 2 ... container, 3 ... wick.

Claims (8)

  1. 　ヒートパイプのウィック形成用銅ペーストであって、
    　銅粒子と、熱分解性樹脂と、分散媒と、を含有し、
    　前記銅粒子は、体積平均粒径が１０～５０μｍである大径銅粒子と、体積平均粒径が０．１～２．０μｍである小径銅粒子と、を含む、銅ペースト。     A copper paste for forming wicks in heat pipes.
    Contains copper particles, a pyrolytic resin, and a dispersion medium,
    The copper particles are a copper paste containing large-diameter copper particles having a volume average particle diameter of 10 to 50 μm and small-diameter copper particles having a volume average particle diameter of 0.1 to 2.0 μm.
  2. 　前記熱分解性樹脂の９５％熱分解温度が３５０℃以下である、請求項１に記載の銅ペースト。 The copper paste according to claim 1, wherein the 95% pyrolysis temperature of the thermally decomposable resin is 350 ° C. or lower.
  3. 　前記大径銅粒子の含有量が、前記銅粒子の全質量を基準として、４０～９０質量％であり、
    　前記小径銅粒子の含有量が、前記銅粒子の全質量を基準として、１０～６０質量％である、請求項１又は２に記載の銅ペースト。     The content of the large-diameter copper particles is 40 to 90% by mass based on the total mass of the copper particles.
    The copper paste according to claim 1 or 2, wherein the content of the small-diameter copper particles is 10 to 60% by mass based on the total mass of the copper particles.
  4. 　前記熱分解性樹脂の含有量が、前記銅粒子１００質量部に対して、１～２０質量部である、請求項１～３のいずれか一項に記載の銅ペースト。 The copper paste according to any one of claims 1 to 3, wherein the content of the pyrolytic resin is 1 to 20 parts by mass with respect to 100 parts by mass of the copper particles.
  5. 　前記大径銅粒子は、タップ密度が１．０～４．５ｇ／ｃｍ３である、請求項１～４のいずれか一項に記載の銅ペースト。 The copper paste according to any one of claims 1 to 4, wherein the large-diameter copper particles have a tap density of 1.0 to 4.5 g / cm 3.
  6. 　前記銅ペーストの粘度が、１０～１２０Ｐａ・ｓである、請求項１～５のいずれか一項に記載の銅ペースト。 The copper paste according to any one of claims 1 to 5, wherein the copper paste has a viscosity of 10 to 120 Pa · s.
  7. 　ヒートパイプのウィックの形成方法であって、
    　請求項１～６のいずれか一項に記載の銅ペーストを印刷する工程と、
    　前記銅ペーストを焼結させる工程と、を備える、ウィックの形成方法。     It is a method of forming a wick of a heat pipe.
    The step of printing the copper paste according to any one of claims 1 to 6,
    A method for forming a wick, comprising a step of sintering the copper paste.
  8. 　請求項１～６のいずれか一項に記載の銅ペーストの焼結体を含むウィックを備える、ヒートパイプ。
          A heat pipe comprising a wick containing the sintered body of the copper paste according to any one of claims 1 to 6.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003222481A (en) * 2002-01-30 2003-08-08 Samsung Electro Mech Co Ltd Heat pipe and method of manufacturing the same
JP2017123326A (en) * 2016-01-04 2017-07-13 古河電気工業株式会社 Dispersion solution of metal particles
WO2018131095A1 (en) * 2017-01-11 2018-07-19 日立化成株式会社 Copper paste for pressureless bonding, bonded body and semiconductor device

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* Cited by examiner, † Cited by third party
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JP2003222481A (en) * 2002-01-30 2003-08-08 Samsung Electro Mech Co Ltd Heat pipe and method of manufacturing the same
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