Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/18—Layered products comprising a layer of synthetic resin characterised by the use of special additives
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/02—Physical, chemical or physicochemical properties
  • B32B7/027—Thermal properties
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L23/00—Details of semiconductor or other solid state devices
  • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
  • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks

Definitions

• the present invention relates to a laminate and a method for manufacturing a laminate.
• thermally conductive materials are widely used to prevent the temperature of LSIs and the like from rising.
• the thermally conductive material can prevent the temperature of the device from rising by diffusing the heat generated by the element or transmitting it to a heat radiating member for discharging it to the outside of the system, such as the atmosphere.
• thermally conductive materials When metals or ceramics are used as such thermally conductive materials, there are problems such as difficulty in reducing weight, poor workability, or low flexibility. Therefore, various heat conductive materials have been proposed that use polymeric materials such as resin or rubber as a base material.
• thermosetting adhesive containing a curing component and a curing agent for the curing component, and a metal filler dispersed in the thermosetting adhesive
• the metal filler includes silver powder and solder powder.
• the solder powder exhibits a melting temperature lower than the heat curing temperature of the thermally conductive adhesive, and reacts with the silver powder under the heat curing conditions of the thermosetting adhesive to reach a temperature lower than the melting temperature of the solder powder.
• the hardening agent is a hardening agent that has flux activity against metal fillers
• the hardening component is a glycidyl ether type epoxy resin
• the hardening agent is a glycidyl ether type epoxy resin.
• a thermally conductive adhesive that is a monoanhydride of tricarboxylic acid has been proposed (see, for example, Patent Document 1).
• An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, an object of the present invention is to provide a laminate and a method for manufacturing the laminate that can achieve high thermal conductivity and low thermal resistance.
• Means for solving the above problem are as follows. That is, ⁇ 1> Base material; a first thermally conductive layer containing a curing component, a curing agent for curing the curing component, first thermally conductive particles, and low melting point metal particles on the base material; a second thermally conductive layer containing a curing component, a curing agent for curing the curing component, second thermally conductive particles, and low melting point metal particles on the first thermally conductive layer; has A portion of the first thermally conductive particles contained in the first thermally conductive layer and a portion of the second thermally conductive particles contained in the second thermally conductive layer are in contact with each other, and the first thermally conductive particles are in contact with each other.
• the volume average particle size of the thermally conductive particles is smaller than the volume average particle size of the second thermally conductive particles
• the laminate is characterized in that the base material includes at least one selected from silicon, aluminum, tungsten, molybdenum, glass, mold resin, stainless steel, and ceramics.
• the ratio (A:B) of the volume average particle diameter A of the first heat conductive particles to the volume average particle diameter B of the second heat conductive particles is 1:2 to 1:50. This is the laminate described in ⁇ 1>.
• ⁇ 3> The laminate according to ⁇ 1> or ⁇ 2>, wherein the first thermally conductive particles have a volume average particle diameter of 0.3 ⁇ m or more and 30 ⁇ m or less.
• ⁇ 4> The laminate according to any one of ⁇ 1> to ⁇ 3>, wherein the second thermally conductive particles have a volume average particle size of 1 ⁇ m or more and 100 ⁇ m or less.
• ⁇ 5> The laminate according to any one of ⁇ 1> to ⁇ 4>, wherein the first and second thermally conductive particles are at least one of copper particles, silver-coated particles, and silver particles. It is.
• ⁇ 6> The laminate according to any one of ⁇ 1> to ⁇ 5>, wherein the low melting point metal particles contain Sn and at least one selected from Bi, Ag, Cu, and In. be.
• ⁇ 7> The laminate according to any one of ⁇ 1> to ⁇ 6>, wherein the curing agent has flux activity with respect to the first and second thermally conductive particles.
• the curing component is at least one of an oxirane ring compound and an oxetane compound.
• ⁇ 9> The laminate according to any one of ⁇ 1> to ⁇ 8>, including a third thermally conductive layer between the first thermally conductive layer and the second thermally conductive layer. . ⁇ 10> The laminate according to ⁇ 9>, wherein the third thermally conductive layer is a copper foil.
• a facing base material facing the base material is provided on the second thermally conductive layer, ⁇ 1> to ⁇ 10>, wherein the opposing base material contains at least one selected from copper, gold, platinum, palladium, silver, zinc, iron, tin, nickel, magnesium, indium, and alloys thereof.
• a conductive layer forming step, including; The method for producing a laminate is characterized in that the base material contains at least one selected from silicon, aluminum, tungsten, molybdenum, glass, mold resin, stainless steel, and ceramics.
• the present invention it is possible to provide a laminate and a method for manufacturing the laminate, which can solve the above-mentioned conventional problems, achieve the above-mentioned objects, and realize high thermal conductivity and low thermal resistance.
• FIG. 1 is a schematic diagram showing an example of a laminate according to the first embodiment.
• FIG. 2 is a schematic diagram showing an example of a laminate according to the second embodiment.
• FIG. 3 is a schematic cross-sectional view showing an example of a heat dissipation structure used in the present invention.
• the laminate of the present invention preferably has a base material, a first thermally conductive layer, a second thermally conductive layer, a third thermally conductive layer and an opposing base material, and further has a third thermally conductive layer and an opposing base material, if necessary. and other members.
• the first thermally conductive layer and the second thermally conductive layer are provided on the base material in this order, and a portion of the first thermally conductive particles and a portion of the second thermally conductive particles are in contact with each other.
• the volume average particle size of the first thermally conductive particles is smaller than the volume average particle size of the second thermally conductive particles, so that silicon, aluminum, tungsten, molybdenum, glass, mold resin, stainless steel Even if the base material has poor solder wettability and is made of at least one selected from ceramics and ceramics, the thermal conductivity can be significantly improved by increasing the contact area.
• Base material The shape, structure, size, material, etc. of the base material are not particularly limited and can be appropriately selected depending on the purpose.
• Examples of the shape of the base material include a plate shape and a sheet shape.
• Examples of the structure of the base material include a single layer structure and a laminated structure.
• the size of the base material can be appropriately selected depending on the purpose and the like.
• the material of the base material is a material that is difficult to wet with solder, and includes at least one selected from silicon, aluminum, tungsten, molybdenum, glass, mold resin, stainless steel, and ceramics.
• the ceramics include aluminum nitride, silicon carbide, alumina, and gallium nitride.
• the mold resin include epoxy resin, silicone resin, urethane resin, and acrylic resin.
• the average thickness of the base material is not particularly limited and can be appropriately selected depending on the purpose.
• the base material may be the heating element (electronic component) itself in the heat dissipation structure.
• the first thermally conductive layer is preferably formed on the base material and in contact with the base material.
• the first thermally conductive layer contains a curing component, a curing agent for curing the curing component, first thermally conductive particles, and low melting point metal particles, and further contains other components as necessary.
• the curing component it is preferable to use at least one of an oxirane ring compound and an oxetane compound.
• the oxirane ring compound is a compound having an oxirane ring, and includes, for example, an epoxy resin.
• the epoxy resin is not particularly limited and can be appropriately selected depending on the purpose, such as glycidyl ether type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A type epoxy resin, trisphenol. type epoxy resin, tetraphenol type epoxy resin, phenol-xylylene type epoxy resin, naphthol-xylylene type epoxy resin, phenol-naphthol type epoxy resin, phenol-dicyclopentadiene type epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin Examples include. These may be used alone or in combination of two or more.
• the oxetane compound is a compound having an oxetanyl group, and may be an aliphatic compound, an alicyclic compound, or an aromatic compound.
• the oxetane compound may be a monofunctional oxetane compound having only one oxetanyl group, or a polyfunctional oxetane compound having two or more oxetanyl groups.
• the oxetane compound is not particularly limited and can be appropriately selected depending on the purpose, such as 3,7-bis(3-oxetanyl)-5-oxanonan, 1,4-bis[(3- ethyl-3-oxetanylmethoxy)methyl]benzene, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,3-bis[(3-ethyl-3-oxetanylmethoxy)methyl]propane , ethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, triethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis(3-ethyl-3-oxetanylmethyl) ether, 1, 4-bis(3-ethyl-3-oxetanylmethoxy)butane, 1,6-bis(3-ethyl-3
• oxetane compound commercially available products can be used, and examples of the commercially available products include the "Aron Oxetane (registered trademark)” series sold by Toagosei Co., Ltd., and the “Aron Oxetane (registered trademark)” series sold by Ube Industries, Ltd. Examples include the “ETERNACOLL (registered trademark)” series.
• glycidyl ether type epoxy resin phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol-dicyclopentadiene type epoxy resin, bisphenol A type epoxy resin, aliphatic epoxy resin, 4, 4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl (OXBP) is preferred.
• the content of the curing component is not particularly limited and can be selected as appropriate depending on the purpose, but it should be 0.5% by mass or more and 60% by mass or less based on the total amount of the first thermally conductive layer. is preferred.
• the curing agent is a curing agent corresponding to the curing component, such as an acid anhydride curing agent, an aliphatic amine curing agent, an aromatic amine curing agent, a phenol curing agent, or a mercaptan curing agent.
• examples include polyaddition type curing agents such as , and catalyst type curing agents such as imidazole. These may be used alone or in combination of two or more. Among these, acid anhydride curing agents are preferred.
• the curing component of the acid anhydride curing agent is an epoxy resin
• no gas is generated during thermal curing, and a long pot life can be achieved when mixed with the epoxy resin. This is preferable because a good balance between physical, chemical, and mechanical properties can be achieved.
• Examples of the acid anhydride curing agent include cyclohexane-1,2-dicarboxylic anhydride and tricarboxylic acid monoanhydride.
• Examples of the monoanhydride of tricarboxylic acid include cyclohexane-1,2,4-tricarboxylic acid-1,2-acid anhydride.
• the curing agent has flux activity, since it improves the wettability of the molten low-melting point metal particles to the thermally conductive particles.
• the method for causing the curing agent to exhibit flux activity include a method of introducing a protonic acid group such as a carboxy group, a sulfonyl group, or a phosphoric acid group into the curing agent by a known method.
• a carboxyl group from the viewpoint of reactivity with the epoxy resin or oxetane compound as a curing component, and examples thereof include carboxyl group-containing organic acids such as glutaric acid and succinic acid.
• it may be a compound modified from glutaric anhydride or succinic anhydride, or a metal salt of an organic acid such as silver glutarate.
• the content of the curing agent is not particularly limited and can be appropriately selected depending on the purpose, but it should be 0.1% by mass or more and 30% by mass or less based on the total amount of the first thermally conductive layer. is preferred.
• the molar equivalent equivalent ratio (C/D) between the curing component C and the curing agent D varies depending on the type of curing component and curing agent used, and cannot be unconditionally defined, but is 0.5 or more. It is preferably 3 or less, more preferably 0.5 or more and 2 or less, and even more preferably 0.7 or more and 1.5 or less.
• the equivalent ratio (C/D) is 0.5 or more and 3 or less, there is an advantage that the low melting point metal particles can sufficiently melt to form a network when the thermally conductive composition is thermoset.
• the first thermally conductive particles are preferably at least one of copper particles, silver-coated particles, and silver particles.
• Examples of the silver-coated particles include silver-coated copper particles, silver-coated nickel particles, and silver-coated aluminum particles.
• the shape of the first thermally conductive particles is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include spherical, flat, granular, and acicular shapes.
• the volume average particle diameter of the first thermally conductive particles is preferably 0.3 ⁇ m or more and 30 ⁇ m or less, more preferably 0.5 ⁇ m or more and 10 ⁇ m or less.
• the volume average particle size of the thermally conductive particles is 0.3 ⁇ m or more and 30 ⁇ m or less, the volume ratio of the first thermally conductive particles to the low melting point metal particles can be increased, and high thermal conductivity and low thermal resistance can be achieved.
• the volume average particle size can be measured, for example, by a laser diffraction/scattering particle size distribution measuring device (product name: Microtrac MT3300EXII).
• solder particles defined in JIS Z3282-1999 are preferably used.
• solder particles examples include Sn-Pb solder particles, Pb-Sn-Sb solder particles, Sn-Sb solder particles, Sn-Pb-Bi solder particles, Sn-Bi solder particles, and Sn-Bi solder particles.
• -Ag based solder particles, Sn-Cu based solder particles, Sn-Pb-Cu based solder particles, Sn-In based solder particles, Sn-Ag based solder particles, Sn-Pb-Ag based solder particles, Pb-Ag based solder Examples include particles, Sn-Ag-Cu solder particles, and the like. These may be used alone or in combination of two or more.
• solder particles containing Sn and at least one selected from Bi, Ag, Cu, and In are preferred, and include Sn-Bi solder particles, Sn-Bi-Ag solder particles, and Sn-Ag solder particles.
• Sn-Bi solder particles Sn-Bi-Ag solder particles
• Sn-Ag solder particles Sn-Ag solder particles.
• -Cu-based solder particles and Sn--In based solder particles are more preferred.
• the shape of the low melting point metal particles is not particularly limited and can be appropriately selected depending on the purpose, and examples include spherical, flat, granular, and acicular shapes.
• the melting point of the low melting point metal particles is preferably 100°C or more and 250°C or less, more preferably 120°C or more and 200°C or less.
• the melting point of the low melting point metal particles is lower than the heat curing temperature of the first heat conductive composition. This is preferable because a network (continuous metal phase) can be formed through conductive particles and high thermal conductivity and low thermal resistance can be achieved.
• the low melting point metal particles react with the heat conductive particles under the thermosetting conditions of the first heat conductive composition to form an alloy having a higher melting point than the low melting point metal particles, so that It can prevent melting and improve reliability. Moreover, the heat resistance of the cured product of the first thermally conductive composition is improved.
• the heat curing treatment of the first thermally conductive composition is performed, for example, at a temperature of 150° C. or more and 200° C. for 30 minutes or more and 2 hours or less.
• the volume average particle diameter of the low melting point metal particles is preferably 10 ⁇ m or less, more preferably 1 ⁇ m or more and 5 ⁇ m or less.
• the volume average particle size of the low melting point metal particles can be measured in the same manner as the volume average particle size of the first thermally conductive particles.
• the volume average particle size of the first heat conductive particles is larger than the volume average particle size of the low melting point metal particles, and the volume average particle size ratio of the heat conductive particles A and the low melting point metal particles B (A/B ) is preferably 2 or more, more preferably 3 or more, and even more preferably 5 or more.
• the upper limit of the volume average particle size ratio (A/B) is preferably 20 or less, more preferably 10 or less.
• the thermally conductive particles become the main component in the first thermally conductive composition, and the first thermally conductive particles and Since the low melting point metal particles present between the first heat conductive particles are melted by heating and alloyed with the first heat conductive particles to form a network, high thermal conductivity and low thermal resistance can be achieved.
• the volume ratio (A/B) of the first heat conductive particles A and the low melting point metal particles B in the first heat conductive layer is preferably 1 or more, more preferably 1.5 or more, and 2 or more. is even more preferable.
• the upper limit of the volume ratio (A/B) is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less.
• the volume ratio (A/B) is 1 or more, the volume ratio of thermally conductive particles having a larger volume average particle diameter than the low melting point metal particles increases, so it is possible to suppress the flow of the molten low melting point metal particles. can.
• separation is less likely to occur at an interface (for example, silicon) where low-melting point metal particles are difficult to wet, the influence of the material of the interface can be suppressed, and the selectivity of the interface material can be improved.
• the first thermally conductive layer preferably contains a polymer in order to impart flexibility and the like.
• the polymer is not particularly limited and can be appropriately selected depending on the purpose.
• the polymer may have a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, Examples include polymers having at least one structure selected from a polyisoprene structure, a polyisobutylene structure, a polyamide structure, and a polycarbonate structure.
• the content of the polymer is preferably 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and 1% by mass or more and 10% by mass or less, based on the total amount of the first thermally conductive layer. is even more preferable.
• the first thermally conductive layer may contain other components as long as the effects of the present invention are not impaired.
• the other components are not particularly limited and can be selected as appropriate depending on the purpose. inhibitors, ultraviolet absorbers, curing accelerators, silane coupling agents, leveling agents, flame retardants, etc.).
• the first thermally conductive composition is prepared by uniformly mixing the curing component, the curing agent, the first thermally conductive particles, the low melting point particles, the polymer, and other components as necessary by a conventional method. It can be prepared by
• the average thickness of the first thermally conductive layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 ⁇ m or more and 100 ⁇ m or less, more preferably 5 ⁇ m or more and 50 ⁇ m or less.
• the second thermally conductive layer contains a curing component, a curing agent for curing the curing component, second thermally conductive particles, and low melting point metal particles, and further contains other components as necessary.
• the second thermally conductive particles are preferably at least one of copper particles, silver-coated particles, and silver particles.
• Examples of the silver-coated particles include silver-coated copper particles, silver-coated nickel particles, and silver-coated aluminum particles.
• the shape of the second thermally conductive particles is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include spherical, flat, granular, and acicular shapes.
• a portion of the first thermally conductive particles contained in the first thermally conductive layer and a portion of the second thermally conductive particles contained in the second thermally conductive layer are in contact with each other, and the first thermally conductive particles are in contact with each other. It is necessary that the volume average particle size of the heat conductive particles is smaller than the volume average particle size of the second heat conductive particles. If the volume average particle size of the first heat conductive particles is larger than the volume average particle size of the second heat conductive particles, the thermal conductivity of the laminate may decrease.
• the ratio (A:B) of the volume average particle size A of the first thermally conductive particles to the volume average particle size B of the second thermally conductive particles is preferably 1:2 to 1:50, and 1 :10 to 1:40 is more preferable.
• the volume average particle diameter of the second thermally conductive particles is preferably 1 ⁇ m or more and 100 ⁇ m or less, more preferably 10 ⁇ m or more and 70 ⁇ m or less, and even more preferably 10 ⁇ m or more and 50 ⁇ m or less.
• the volume average particle size of the second thermally conductive particles can be measured in the same manner as the volume average particle size of the first thermally conductive particles.
• the curing component, curing agent, low melting point metal particles, polymer, and other components in the second thermally conductive layer are the curing component, curing agent, low melting point metal particles, polymer, and other components in the first thermally conductive layer described above. Since the components are the same as those in , the details of these will be omitted.
• the average thickness of the second thermally conductive layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 20 ⁇ m or more and 300 ⁇ m or less, more preferably 50 ⁇ m or more and 200 ⁇ m or less.
• the third thermally conductive layer is formed between the first thermally conductive layer and the second thermally conductive layer, and the third thermally conductive layer may be a single layer, or may have two or more layers. There may be multiple layers.
• the third thermally conductive layer is preferably a copper foil from the viewpoint of thermal conductivity.
• the average thickness of the third thermally conductive layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 ⁇ m or more and 200 ⁇ m or less, more preferably 10 ⁇ m or more and 100 ⁇ m or less.
• the facing base material is arranged to face the base material, and there are no particular limitations on its shape, structure, size, material, etc., and can be appropriately selected depending on the purpose.
• Examples of the shape of the facing substrate include a plate shape and a sheet shape.
• Examples of the structure of the opposing base material include a single layer structure and a laminated structure. The size of the opposing base material can be appropriately selected depending on the application and the like.
• the material of the opposing base material is a material easily wetted by solder, and includes at least one member selected from copper, gold, platinum, palladium, silver, zinc, iron, tin, nickel, magnesium, indium, and alloys thereof. include.
• the average thickness of the facing substrate is not particularly limited and can be appropriately selected depending on the purpose.
• the opposing base material may be the heat spreader itself in the heat dissipation structure.
• the method for manufacturing a laminate of the present invention includes a first thermally conductive layer forming step, a second thermally conductive layer forming step, and further includes other steps as necessary.
• First thermally conductive layer forming step In the first thermally conductive layer forming step, a first thermally conductive layer containing a curing component, a curing agent for curing the curing component, first thermally conductive particles, and low melting point metal particles is formed on the base material. This is the process of forming.
• the base material includes at least one selected from silicon, aluminum, tungsten, molybdenum, glass, mold resin, stainless steel, and ceramics.
• the curing component, curing agent, first thermally conductive particles, and low melting point metal particles are the curing component, curing agent, first thermally conductive particles, and low melting point metal particles contained in the first thermally conductive layer. Since it is similar to the low melting point metal particles, its explanation will be omitted.
• a method for forming the first thermally conductive layer for example, (1) a first thermally conductive layer containing a curing component, a curing agent for curing the curing component, first thermally conductive particles, and low melting point metal particles; A method of applying a composition onto a substrate and curing it, (2) containing a curing component, a curing agent for curing the curing component, first thermally conductive particles, and low melting point metal particles on a support with a release layer. Examples include a method of forming a cured product layer containing a cured product of the first thermally conductive composition and transferring the cured product layer onto a substrate. In (2) above, the support is peeled off when transferring the cured material layer onto the base material.
• Examples of the method for applying the first thermally conductive composition to the base material in (1) include an inkjet method, a blade coating method, a gravure coating method, a gravure offset coating method, a bar coating method, a roll coating method, and a knife method.
• a second thermally conductive layer containing a curing component, a curing agent for curing the curing component, second thermally conductive particles, and low melting point metal particles is formed on the first thermally conductive layer. This is a step of forming a thermally conductive layer.
• the curing component, the curing agent, the second thermally conductive particles, and the low melting point metal particles are the curing component, the curing agent, the second thermally conductive particles contained in the second thermally conductive layer, and the above-mentioned low melting point metal particles, so the explanation thereof will be omitted.
• the method for forming the second thermally conductive layer includes, for example, (1) a second thermally conductive layer containing a curing component, a curing agent for curing the curing component, second thermally conductive particles, and low melting point metal particles; A method of applying a composition onto a first thermally conductive layer and curing it, (2) a curing component on a support with a release layer, a curing agent for curing the curing component, a second thermally conductive particle, and a low melting point Examples include a method of forming a cured material layer containing a cured product of a second thermally conductive composition containing metal particles, and transferring the cured material layer onto the first thermally conductive layer. In (2) above, the support is peeled off when transferring the cured material layer onto the first thermally conductive layer.
• Examples of the method for applying the second thermally conductive composition in (1) above to the first thermally conductive layer include an inkjet method, a blade coating method, a gravure coating method, a gravure offset coating method, a bar coating method, and a roll coating method.
• FIG. 1 is a schematic diagram showing an example of a laminate according to the first embodiment.
• the laminate 10 in FIG. 1 includes a first thermally conductive layer 12 containing first thermally conductive particles 15 on a base material 11, and a second thermally conductive layer 12 on the first thermally conductive layer 12. 16, and an opposing base material 14 on the second heat conductive layer 13.
• a portion of the first thermally conductive particles 15 included in the first thermally conductive layer 12 and a portion of the second thermally conductive particles 16 included in the second thermally conductive layer 13 are in contact with each other, and the first thermally conductive particles 15 are in contact with each other.
• the volume average particle size of the second heat conductive particles 15 is smaller than the volume average particle size of the second heat conductive particles 16.
• FIG. 2 is a schematic diagram showing an example of a laminate according to the second embodiment.
• the laminate 20 of FIG. 2 has a first thermally conductive layer 12 containing first thermally conductive particles 15 on a base material 11, and a third layer made of copper foil on the first thermally conductive layer 12.
• a second thermally conductive layer 13 containing second thermally conductive particles 16 on the third thermally conductive layer 17; and a counter substrate 14 on the second thermally conductive layer 13. has.
• the volume average particle diameter of the first heat conductive particles 15 is smaller than the volume average particle diameter of the second heat conductive particles 16.
• the laminate of the present invention can be used, for example, with a thermal interface material (TIM), an LED chip, or an IC that fills a minute gap between a heat source such as an LSI and a heat sink to allow heat to flow smoothly between the two.
• a thermal interface material TIM
• an LED chip or an IC that fills a minute gap between a heat source such as an LSI and a heat sink to allow heat to flow smoothly between the two.
• the heat dissipation board on which the chip is mounted can be suitably used when bonding to a heat sink to configure a power LED module or a power IC module.
• power LED modules include wire bonding type and flip chip type
• power IC modules include wire bonding type
• the heat dissipation structure used in the present invention is composed of a heating element, the laminate of the present invention, and a heat dissipation member.
• the heating element is not particularly limited and can be selected as appropriate depending on the purpose, for example, CPU (Central Processing Unit), MPU (Micro Processing Unit), GPU (Graphics Processing Unit). Electronic parts such as Can be mentioned.
• CPU Central Processing Unit
• MPU Micro Processing Unit
• GPU Graphics Processing Unit
• the heat dissipation member is not particularly limited as long as it is a structure that dissipates heat generated by electronic components (heat generating elements), and can be appropriately selected depending on the purpose.For example, heat spreaders, heat sinks, vapor chambers, heat Examples include pipes.
• the heat spreader is a member for efficiently transmitting heat from the electronic component to other components.
• the material of the heat spreader is not particularly limited and can be appropriately selected depending on the purpose, such as copper and aluminum.
• the heat spreader usually has a flat plate shape.
• the heat sink is a member for releasing heat from the electronic component into the air.
• the material of the heat sink is not particularly limited and can be appropriately selected depending on the purpose, such as copper and aluminum.
• the heat sink has, for example, a plurality of fins.
• the heat sink includes, for example, a base portion and a plurality of fins extending in non-parallel directions (for example, perpendicular directions) to one surface of the base portion.
• the heat spreader and the heat sink generally have a solid structure with no internal space.
• the vapor chamber is a hollow structure.
• a volatile liquid is sealed in the internal space of the hollow structure.
• Examples of the vapor chamber include a plate-shaped hollow structure such as a hollow structure of the heat spreader and a hollow structure of the heat sink.
• the heat pipe is a cylindrical, substantially cylindrical, or flat cylindrical hollow structure.
• a volatile liquid is sealed in the internal space of the hollow structure.
• FIG. 3 is a schematic cross-sectional view showing an example of a semiconductor device as a heat dissipation structure.
• the laminate 7 of the present invention radiates heat generated by an electronic component 3 such as a semiconductor element, and as shown in FIG. 3 and the heat spreader 2. Further, the thermally conductive sheet 1 is sandwiched between the heat spreader 2 and the heat sink 5.
• the heat spreader 2 is formed into a rectangular plate shape, for example, and has a main surface 2a facing the electronic component 3, and a side wall 2b erected along the outer periphery of the main surface 2a.
• a heat conductive sheet 1 is provided on a main surface 2a surrounded by side walls 2b, and a heat sink 5 is provided on the other surface 2c opposite to the main surface 2a via the heat conductive sheet 1.
• the heat spreader 2 is formed using, for example, copper or aluminum, which has good thermal conductivity, because the higher the thermal conductivity, the lower the thermal resistance, and the more efficiently the heat spreader 2 absorbs the heat of the electronic components 3 such as semiconductor elements. can do.
• the electronic component 3 is, for example, a semiconductor element such as a BGA, and is mounted on the wiring board 6. Further, the heat spreader 2 also has the front end surface of the side wall 2b mounted on the wiring board 6, so that the side wall 2b surrounds the electronic component 3 at a predetermined distance.
• a heat radiating member is formed that absorbs the heat generated by the electronic component 3 and radiates the heat from the heat sink 5.
• thermoly conductive composition (Examples 1 to 5, Comparative Examples 1 to 3, and Reference Example 1) ⁇ Preparation of thermally conductive composition>
• the compositions and contents listed in Tables 1 to 3 were uniformly mixed using a stirring device (foam remover Rentaro, automatic revolution mixer, manufactured by Shinky Co., Ltd.), and the first thermally conductive composition and the second thermally conductive composition were mixed uniformly.
• a thermally conductive composition was prepared. Note that the content of each component in Tables 1 to 3 is in parts by mass.
• the first thermally conductive composition was applied on a 30 mm x 30 mm x 2 mm base material (silicon) according to the descriptions in Tables 1 to 3, and then , a second thermally conductive composition was applied on the first thermally conductive layer, a 30 mm x 30 mm x 2 mm opposing base material (copper) was laminated on the second thermally conductive composition, and the layer was heated at 150°C. It was heated for 60 minutes and cured to form a laminate having a first thermally conductive layer with an average thickness of 10 ⁇ m and a second thermally conductive layer with an average thickness of 70 ⁇ m.
• Example 2 a copper foil with an average thickness of 30 ⁇ m was used as the third thermally conductive layer.
• Comparative Example 2 a laminate was formed in the same manner as Examples 1 to 5 and Comparative Example 3, except that the second thermally conductive composition was not used.
• Thermal resistance (°C ⁇ cm 2 /W) of each of the obtained laminates was measured by a method based on ASTM-D5470.
• the thermal resistance of the cured product was calculated by subtracting the thermal resistance of the base material and the opposing substrate from the results, and the thermal impedance (Kmm 2 /W) was calculated from the thermal resistance and the area of the cured product.
• Thermal conductivity is 15 W/m ⁇ K or more
• Thermal conductivity is 10 W/m ⁇ K or more and less than 15 W/m ⁇ K
• Thermal conductivity is less than 10 W/m ⁇ K
• Second thermally conductive particles *First thermally conductive particles 1: Ag particles, manufactured by DOWA Electronics Co., Ltd., volume average particle diameter Dv: 1 ⁇ m *First thermally conductive particles 2: Ag-coated Cu particles, manufactured by Fukuda Metal Foil and Powder Industries Co., Ltd., volume average particle diameter Dv: 5 ⁇ m *First thermally conductive particles 3: Ag-coated Cu particles, manufactured by Fukuda Metal Foil and Powder Industries Co., Ltd., volume average particle diameter Dv: 40 ⁇ m
• the laminate of the present invention can realize high thermal conductivity and low thermal resistance as a thermal interface material (TIM), so it can be used, for example, in CPUs, MPUs, power transistors, LEDs, lasers, etc. whose element operation efficiency and life span are adversely affected by temperature. Suitable for use around various electrical devices such as diodes.
• TIM thermal interface material

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• 2022
  • 2022-06-08 JP JP2022093004A patent/JP2023179989A/ja active Pending
• 2023
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