Stacked body and method for manufacturing the same

Abstract

Provided is a laminate having: a substrate, and a thermally conductive layer containing, in a state in which metal-coated resin particles are separated and arranged at predetermined intervals on the substrate, a curing component, a curing agent that cures the curing component, thermally conductive particles, and low-melting-point metal particles, the metal-coated resin particles being in contact with the substrate, the volume average particle diameter of the metal-coated resin particles being smaller than the volume average particle diameter of the thermally conductive particles, and the substrate containing at least one selected from the group consisting of silicon, aluminum, tungsten, molybdenum, glass, a molding resin, stainless steel, and ceramic.

Description

Technical Field

[0001] This invention relates to laminates and methods for manufacturing laminates. Background Technology

[0002] In various electronic devices, such as Large Scale Integration (LSI), if the LSI itself is exposed to high temperatures for extended periods due to the heat generated by the components used, there is a concern about malfunctions and failures. Therefore, thermally conductive materials are widely used to prevent the LSI from overheating. These materials prevent the device from overheating by diffusing or conducting the heat generated by the components to heat-dissipating components that release it to the atmosphere or other external components.

[0003] If metals or ceramics are used as such thermal conductive materials, problems arise such as difficulty in achieving lightweight properties, poor processability, or reduced flexibility. Therefore, various thermal conductive materials using polymers formed from resins or rubbers as the base material have been proposed.

[0004] For example, a thermally conductive adhesive has been proposed comprising a 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 comprising silver powder and solder powder, the solder powder exhibiting a melting temperature lower than the thermosetting treatment temperature of the thermally conductive adhesive, and reacting with the silver powder under the thermosetting treatment conditions of the thermosetting adhesive to generate a high-melting-point solder alloy exhibiting a melting point higher than the melting temperature of the solder powder, the curing agent being a curing agent having flux activity for the metal filler, the curing component being a glycidyl ether type epoxy resin, and the curing agent being a tricarboxylic acid monoanhydride (for example, see Patent Document 1).

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 5796242 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, in the prior art described in the aforementioned Patent Document 1, the heat dissipation module in the heat-dissipating structure can achieve high thermal conductivity through metal bonding. However, the heat-generating element (electronic component) in the heat-dissipating structure is often made of materials such as silicon, which presents a challenge in achieving high thermal conductivity through metal bonding.

[0010] The objective of this invention is to solve the aforementioned problems and achieve the following objective: to provide a laminate capable of achieving high thermal conductivity and a method for manufacturing the laminate.

[0011] Methods for solving problems

[0012] The method for solving the above-mentioned problem is as follows. That is,

[0013] <1> A laminate, characterized in that it comprises: a substrate, and

[0014] The substrate described above contains metal-coated resin particles arranged at predetermined intervals, and includes a thermally conductive layer comprising a curing component, a curing agent for curing the curing component, thermally conductive particles, and low-melting-point metal particles.

[0015] The aforementioned metal-coated resin particles came into contact with the aforementioned substrate, and the volume average particle size of the aforementioned metal-coated resin particles was smaller than the volume average particle size of the aforementioned thermally conductive particles.

[0016] The aforementioned substrate comprises at least one selected from silicon, aluminum, tungsten, molybdenum, glass, molding resin, stainless steel, and ceramics.

[0017] <2> According to the laminate described in <1> above, the metal-coated resin particles are in contact with a portion of the thermally conductive particles contained in the thermally conductive layer.

[0018] <3> According to the laminate described in <1> or <2> above, the ratio (A:B) of the volume average particle size A of the metal-coated resin particles to the volume average particle size B of the thermally conductive particles is 1:2 to 1:20.

[0019] <4> In the laminate according to any one of <1> to <3> above, the volume average particle size of the metal-coated resin particles is 0.3 μm or more and 30 μm or less.

[0020] <5> In the laminate according to any one of <1> to <4> above, the volume average particle size of the thermally conductive particles is 1 μm or more and 100 μm or less.

[0021] <6> In the laminate according to any one of <1> to <5> above, the metal-coated resin particles are selected from at least one of gold-plated resin particles, silver-plated resin particles, copper-plated resin particles and nickel-plated resin particles.

[0022] <7> In the laminate according to any one of <1> to <6> above, the thermally conductive particles are at least one of copper particles, silver-coated particles and silver particles.

[0023] <8> The laminate according to any one of <1> to <7> above, wherein the low melting point metal particles comprise Sn and at least one selected from Bi, Ag, Cu and In.

[0024] <9> The laminate according to any one of <1> to <8> above, wherein the cured component is at least one of an ethylene oxide cyclic compound and an oxobutane compound.

[0025] <10> The laminate according to any one of <1> to <9> above has a counter substrate on the thermally conductive layer that is opposite to the substrate.

[0026] The aforementioned opposing substrate comprises at least one selected from copper, gold, platinum, palladium, silver, zinc, iron, tin, nickel, magnesium, indium, and alloys thereof.

[0027] <11> A method for manufacturing a laminate, characterized by comprising the following steps:

[0028] A thermally conductive layer forming process is performed on a substrate, comprising a thermally conductive layer containing metal-coated resin particles separated and arranged at predetermined intervals, and including a curing component, a curing agent for curing the curing component, thermally conductive particles, and low-melting-point metal particles.

[0029] The aforementioned substrate comprises at least one selected from silicon, aluminum, tungsten, molybdenum, glass, molding resin, stainless steel, and ceramics.

[0030] The effects of the invention

[0031] According to the present invention, the aforementioned problems can be solved and the above-mentioned objectives can be achieved, and a laminate capable of achieving high thermal conductivity and a method for manufacturing the laminate can be provided. Attached Figure Description

[0032] Figure 1A This is a schematic diagram showing an example of the laminated body according to the first embodiment before pressing.

[0033] Figure 1B This is a schematic diagram showing an example of the laminated body according to the first embodiment after pressing.

[0034] Figure 2 A schematic cross-sectional view showing an example of the heat-dissipating structure used in this invention.

[0035] Figure 3 This is a cross-sectional SEM image of the location where the thermally conductive layer meets the substrate in the laminate of Example 4. Detailed Implementation

[0036] (Layered structure)

[0037] The laminate of the present invention comprises: a substrate, and a thermally conductive layer comprising metal-coated resin particles spaced apart and arranged at predetermined intervals, preferably having an opposing substrate, and further having other components as needed.

[0038] In this invention, by having a thermally conductive layer on a substrate in which metal-coated resin particles are separated and arranged at predetermined intervals, the metal-coated resin particles are in contact with the substrate, the volume average particle size of the metal-coated resin particles is smaller than the volume average particle size of the thermally conductive particles, and the contact area is increased due to the deformation of the metal-coated resin particles, the thermal conductivity can be significantly improved even for substrates with poor solder wettability formed from at least one of silicon, aluminum, tungsten, molybdenum, glass, molding resin, stainless steel and ceramics.

[0039] <Substrate>

[0040] There are no particular restrictions on the shape, structure, size, and material of the aforementioned substrates; they can be selected appropriately according to the purpose.

[0041] Examples of the shape of the aforementioned substrate include, for example, a plate or sheet. Examples of the structure of the aforementioned substrate include a single-layer structure and a laminated structure. Examples of the size of the aforementioned substrate can be appropriately selected according to the application and other factors.

[0042] The substrate material is one that is not easily wetted by solder, and includes at least one material selected from silicon, aluminum, tungsten, molybdenum, glass, molding resin, stainless steel, and ceramics. Examples of ceramics include aluminum nitride, silicon carbide, aluminum oxide, and gallium nitride. Examples of molding resins include epoxy resin, silicone resin, urethane resin, and acrylic resin.

[0043] There are no particular limitations on the average thickness of the aforementioned substrates, and they can be appropriately selected according to the purpose.

[0044] The aforementioned substrate can be the heat-generating element (electronic component) itself in the heat-generating structure.

[0045] <Heat-conducting layer>

[0046] The aforementioned thermally conductive layer contains metal-coated resin particles separated and arranged at predetermined intervals, and includes a curing component, a curing agent for curing the curing component, thermally conductive particles, and low-melting-point metal particles, and may further contain other components as needed.

[0047] -Fixed components-

[0048] As the curing component, at least one of ethylene oxide cyclic compounds and oxobutane compounds is preferably used.

[0049] --Ethylene oxide cyclic compounds--

[0050] The aforementioned ethylene oxide ring compounds are compounds containing an ethylene oxide ring, such as epoxy resins.

[0051] There are no particular limitations on the epoxy resins mentioned above; they can be appropriately selected according to the purpose. Examples include glycidyl ether type epoxy resins, phenolic varnish type epoxy resins, cresolic varnish type epoxy resins, bisphenol A type epoxy resins, triphenol type epoxy resins, tetraphenol type epoxy resins, phenol-phthalimide type epoxy resins, naphthol-phthalimide type epoxy resins, phenol-naphthol type epoxy resins, phenol-dicyclopentadiene type epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins. One type can be used alone, or two or more types can be used in combination.

[0052] --Oxycyclic butane compounds--

[0053] The above-mentioned oxetane compounds are compounds containing oxetane groups, and can be aliphatic, alicyclic, or aromatic compounds.

[0054] The aforementioned oxetane compounds can be monofunctional oxetane compounds having only one oxetane alkyl group, or polyfunctional oxetane compounds having two or more oxetane alkyl groups.

[0055] There are no particular limitations on the aforementioned oxetane compounds, and appropriate selection can be made according to the purpose. Examples include 3,7-bis(3-oxetane)-5-oxa-nonane, 1,4-bis[(3-ethyl-3-oxetane-methoxy)methyl]benzene, 1,2-bis[(3-ethyl-3-oxetane-methoxy)methyl]ethane, 1,3-bis[(3-ethyl-3-oxetane-methoxy)methyl]propane, ethylene glycol bis(3-ethyl-3-oxetane-methyl) ether, triethylene glycol bis(3-ethyl-3-oxetane-methyl) ether, tetraethylene glycol bis(3-ethyl-3-oxetane-methyl) ether, and 1,4-bis(3-ethyl-3-oxetane-methyl)propane. 3-Oxetrazolylbutane, 1,6-bis(3-ethyl-3-oxetrazolylbutane), 3-ethyl-3-(phenoxy)methyloxetane, 3-ethyl-3-(cyclohexyloxymethyl)oxetane, 3-ethyl-3-(2-ethylhexyloxymethyl)oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(chloromethyl)oxetane, 3-ethyl-3{[(3-ethyloxetane-3-yl)methoxy]methyl}oxetane, phenylenediamine dioxetane, 4,4'-bis[(3-ethyl-3-oxetrazolyl)methoxymethyl]biphenyl (OXBP), etc. They can be used individually or in combination of two or more.

[0056] As the aforementioned oxetane compounds, commercially available products can be used. Examples of such commercially available products include, for instance, the "ARONE OXETANE (registered trademark)" series sold by Toa Synthetic Co., Ltd., and the "ETERNACOLL (registered trademark)" series sold by Ube Industries, Ltd.

[0057] Among the above-mentioned ethylene oxide cyclic compounds and oxetane compounds, the preferred types are glycidyl ether type epoxy resin, phenolic varnish type epoxy resin, cresol phenolic varnish type epoxy resin, phenol-dicyclopentadiene type epoxy resin, bisphenol A type epoxy resin, aliphatic epoxy resin, and 4,4'-bis[(3-ethyl-3-oxetane)methoxymethyl]biphenyl (OXBP).

[0058] The content of the above-mentioned curing components is not particularly limited and can be appropriately selected according to the purpose. It is preferably 0.5% by mass or more and 60% by mass or less relative to the total amount of the first thermally conductive layer.

[0059] -Curing agent-

[0060] Examples of curing agents corresponding to the curing components include, for instance, addition-polymer curing agents such as anhydride-based curing agents, aliphatic amine-based curing agents, aromatic amine-based curing agents, phenol-based curing agents, and thiol-based curing agents, as well as catalytic curing agents such as imidazole. One of these can be used alone, or two or more can be used in combination. Among these, anhydride-based curing agents are preferred. When the curing component is epoxy resin, the aforementioned anhydride-based curing agents do not generate gas during heat curing, and when mixed with epoxy resin, they can achieve a long shelf life. Furthermore, they are preferred from the perspective of achieving a good balance between the electrical, chemical, and mechanical properties of the resulting cured product.

[0061] Examples of anhydride-based curing agents include, for example, cyclohexane-1,2-dicarboxylic anhydride and monocarboxylic acid anhydrides. Examples of monocarboxylic acid anhydrides include, for example, cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride.

[0062] The aforementioned curing agent exhibits flux activity, which is preferred from the perspective of improving the wettability of molten low-melting-point metal particles relative to thermally conductive particles. Examples of methods for the curing agent to exhibit flux activity include, for instance, introducing proton acid groups such as carboxyl groups, sulfonyl groups, and phosphate groups into the curing agent using known methods. Among these, introducing carboxyl groups is preferred from the perspective of reactivity with epoxy resins or oxobutane compounds that are curing components; examples include organic acids containing carboxyl groups such as glutaric acid and succinic acid. Furthermore, compounds modified from glutaric anhydride or succinic anhydride, or metal salts of organic acids such as silver glutarate, can also be used.

[0063] The content of the curing agent is not particularly limited and can be appropriately selected according to the purpose. It is preferably 0.1% by mass or more and 30% by mass or less relative to the total amount of the thermally conductive layer.

[0064] The molar equivalent ratio (C / D) of the curing component C to the curing agent D varies depending on the type of curing component and curing agent used, and cannot be specified in general terms. It is preferably 0.5 to 3 or less, more preferably 0.5 to 2 or less, and even more preferably 0.7 to 1.5 or less. If the above equivalent ratio (C / D) is 0.5 to 3 or less, it has the advantage that when the thermally conductive composition is thermally cured, the low-melting-point metal particles are fully melted and a network can be formed.

[0065] -Thermoconducting particles-

[0066] The preferred thermally conductive particles are at least any one of copper particles, silver-coated particles, and silver particles.

[0067] Examples of silver-coated particles include silver-coated copper particles, silver-coated nickel particles, and silver-coated aluminum particles.

[0068] There are no particular restrictions on the shape of the aforementioned heat-conducting particles; they can be appropriately selected according to the purpose. Examples include spherical, flat, granular, and needle-shaped particles.

[0069] The volume average particle size of the aforementioned thermally conductive particles is preferably 1 μm to 100 μm, more preferably 10 μm to 70 μm, and even more preferably 10 μm to 50 μm. If the volume average particle size of the thermally conductive particles is 1 μm to 100 μm, the volume ratio of the thermally conductive particles to the low-melting-point metal particles can be increased, thereby achieving high thermal conductivity. The aforementioned volume average particle size can be measured, for example, by laser diffraction and a random particle size distribution measuring device (product name: MicrotracMT3300EXII).

[0070] -Low melting point metal particles-

[0071] For the aforementioned low-melting-point metal particles, the solder particles specified in JIS Z3282-1999 are suitable.

[0072] Examples of solder particles include, for instance, Sn-Pb-based solder particles, Pb-Sn-Sb-based solder particles, Sn-Sb-based solder particles, Sn-Pb-Bi-based solder particles, Sn-Bi-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 particles, and Sn-Ag-Cu-based solder particles. One type may be used alone, or two or more types may be used together. Among these, solder particles containing Sn and at least one selected from Bi, Ag, Cu, and In are preferred, and Sn-Bi-based solder particles, Sn-Bi-Ag-based solder particles, Sn-Ag-Cu-based solder particles, and Sn-In-based solder particles are more preferred.

[0073] There are no particular restrictions on the shape of the aforementioned low-melting-point metal particles; they can be appropriately selected according to the purpose. Examples include spherical, flat, granular, and needle-shaped particles.

[0074] The melting point of the aforementioned low-melting-point metal particles is preferably 100°C to 250°C, and more preferably 120°C to 200°C.

[0075] The melting point of the aforementioned low-melting-point metal particles is lower than the heat curing temperature of the thermally conductive composition. It is preferable to achieve high thermal conductivity by using molten low-melting-point metal particles in the cured thermally conductive composition to form a network (a continuous phase of metal).

[0076] The aforementioned low-melting-point metal particles react with the aforementioned thermally conductive particles under the thermosetting treatment conditions of the aforementioned thermally conductive composition to form an alloy exhibiting a higher melting point compared to the aforementioned low-melting-point metal particles, thereby preventing melting at high temperatures and improving reliability. Furthermore, the heat resistance of the cured thermally conductive composition is improved.

[0077] The thermal curing treatment of the above-mentioned thermally conductive composition is, for example, carried out at a temperature of 150°C or higher and 200°C for 30 minutes or more and 2 hours or less.

[0078] The volume average particle size of the aforementioned low-melting-point metal particles is preferably 10 μm or less, more preferably 1 μm or more and 5 μm or less. If the volume average particle size of the low-melting-point metal particles is 10 μm or less, the volume ratio of low-melting-point metal particles to thermally conductive particles can be reduced, thereby achieving high thermal conductivity.

[0079] The volume average particle size of the aforementioned low-melting-point metal particles can be determined in the same manner as the volume average particle size of the aforementioned thermally conductive particles.

[0080] The volume average particle size of the aforementioned thermally conductive particles is larger than that of the aforementioned low-melting-point metal particles. The volume average particle size ratio (A / B) of the aforementioned thermally conductive particles A to the aforementioned low-melting-point metal particles B is preferably 2 or more, more preferably 3 or more, and even more preferably 5 or more. The upper limit of the aforementioned volume average particle size ratio (A / B) is preferably 20 or less, more preferably 10 or less.

[0081] By using low-melting-point metal particles with a smaller volume average particle size compared to the aforementioned thermally conductive particles, the aforementioned thermally conductive particles become the main component in the thermally conductive composition. The low-melting-point metal particles that exist between the aforementioned thermally conductive particles melt upon heating and alloy with the thermally conductive particles to form a network, thereby achieving high thermal conductivity.

[0082] The volume ratio (A / B) of the heat-conducting particles A to the low-melting-point metal particles B in the heat-conducting layer is preferably 1 or more, more preferably 1.5 or more, and even more preferably 2 or more. The upper limit of the above volume ratio (A / B) is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less. If the volume ratio (A / B) is 1 or more, the volume proportion of heat-conducting particles with a larger volume average particle size compared to the low-melting-point metal particles increases, thus suppressing the flow of molten low-melting-point metal particles. Furthermore, the low-melting-point metal particles are less prone to separation even at interfaces that are not easily wetted (e.g., aluminum), thus suppressing the influence of the interface material and improving the selectivity of the interface material.

[0083] -polymer-

[0084] To impart flexibility and other properties, the thermally conductive layer preferably contains a polymer.

[0085] There are no particular limitations on the polymers mentioned above, and they can be appropriately selected according to the purpose. Examples include polymers that have at least one structure selected from polybutadiene, polysiloxane, poly(meth)acrylate, polyalkylene, polyalkyleneoxy, polyisoprene, polyisobutylene, polyamide, and polycarbonate within the molecule.

[0086] The content of the polymer relative to the total amount of the thermally conductive layer is preferably 1% to 50% by mass, more preferably 1% to 30% by mass, and even more preferably 1% to 10% by mass.

[0087] -Other ingredients-

[0088] The aforementioned thermally conductive layer may contain other components as long as it does not impair the effectiveness of the present invention. There are no particular limitations on these other components; they can be appropriately selected according to the purpose. Examples include thermally conductive particles other than metals (e.g., aluminum nitride, alumina, carbon fiber, etc.), additives (e.g., antioxidants, UV absorbers, curing accelerators, silane coupling agents, leveling agents, flame retardants, etc.).

[0089] In this invention, the aforementioned thermally conductive layer comprises metal-coated resin particles spaced apart and arranged in a manner that allows them to be arranged at predetermined intervals. That is, the thermally conductive layer has a particle arrangement layer on the surface of the side in contact with the substrate.

[0090] The aforementioned metal-coated resin particles come into contact with the aforementioned substrate, preferably with a portion of the thermally conductive particles contained in the aforementioned thermally conductive layer. This enables the achievement of high thermal conductivity.

[0091] The term "metal-coated resin particles arranged at predetermined intervals on the surface of the side of the thermally conductive layer that is in contact with the substrate" can be easily observed using an optical microscope when the substrate is transparent to visible light, such as glass. Furthermore, when the substrate is transparent to infrared light, such as silicon, it can be observed using an infrared microscope. Additionally, when the substrate is made of molding resin or ceramic, it can be observed using an X-ray microscope.

[0092] -Metal-coated resin particles-

[0093] As for the aforementioned metal-coated resin particles, resin particles with high thermal conductivity and relatively softness are preferred. Examples include gold-plated resin particles, silver-plated resin particles, copper-plated resin particles, and nickel-plated resin particles. One type can be used alone, or two or more types can be used in combination. Among these, gold-plated resin particles are preferred from the perspective of thermal conductivity and stability.

[0094] Examples of materials that can be used for the aforementioned resin particles include, for example, divinylbenzene polymers, polystyrene resins, epoxy resins, phenolic resins, acrylic resins, acrylonitrile-styrene (AS) resins, and benzoguanamine resins. One of these can be used alone, or two or more can be used in combination.

[0095] The volume average particle size of the aforementioned metal-coated resin particles is preferably 0.3 μm or more and 30 μm or less, more preferably 0.5 μm or more and 10 μm or less.

[0096] The volume average particle size of the aforementioned metal-coated resin particles can be measured in the same manner as the volume average particle size of the aforementioned thermally conductive particles.

[0097] Preferably, at least a portion of the aforementioned metal-coated resin particles are exposed from the aforementioned thermally conductive layer. Thus, when the laminate is pressed, the metal-coated resin particles deform while the adhesive component melts and reaches the substrate surface, improving adhesion to the thermally conductive layer.

[0098] When viewed from above, the aforementioned metal-coated resin particles are arranged in a repeating, predetermined pattern. For example, the arrangement of the metal-coated resin particles can be a square lattice arrangement when viewed from above. Other examples of regular arrangements of the metal-coated resin particles include rectangular lattices, rhomboid lattices, hexagonal lattices, and triangular lattices. Multiple combinations of lattice shapes can be used in the arrangement of the metal-coated resin particles. As a method of arranging the metal-coated resin particles, rows of particles arranged in a straight line at predetermined intervals can be arranged side-by-side at predetermined intervals. Densely arranged areas and sparsely arranged areas of the metal-coated resin particles can be regularly repeated. It is preferable that each metal-coated resin particle is independently separated, which is preferable from the perspective of improving thermal conductivity. Furthermore, the regular arrangement of multiple metal-coated resin particles connected or close together to form a unit is also included.

[0099] When the aforementioned metal-coated resin particles are arranged regularly, the lattice axis or arrangement axis of the arrangement can be parallel or intersecting with at least one of the length direction and the direction perpendicular to the length direction of the thermally conductive layer.

[0100] There is no particular limitation on the interparticle distance of the metal-coated resin particles, which can be appropriately selected according to the purpose. For example, the closest interparticle distance is preferably 0.5 times or more the volume average particle size of the metal-coated resin particles, more preferably 0.7 times or more. On the other hand, the closest interparticle distance is preferably 100 times or less the volume average particle size of the metal-coated resin particles, more preferably 50 times or less.

[0101] The preferred particle density of the metal-coated resin is 100 particles / mm². 2 The above is preferred to be 300 pieces / mm. 2 The above 70,000 pieces / mm 2 The following is a further preferred value: 6,000 pieces / mm 2 The above 45,000 pieces / mm 2 the following.

[0102] The average thickness of the above-mentioned heat-conducting layer is not particularly limited and can be appropriately selected according to the purpose. It is preferably 0.1 μm to 100 μm, and more preferably 1 μm to 30 μm.

[0103] <Opposite substrate>

[0104] The aforementioned opposing substrates are arranged opposite each other, and there are no particular restrictions on their shape, structure, size, material, etc., and they can be appropriately selected according to the purpose.

[0105] Examples of the shape of the aforementioned opposing substrate include, for example, a plate or sheet. Examples of the structure of the aforementioned opposing substrate include a single-layer structure or a laminated structure. The size of the aforementioned opposing substrate can be appropriately selected according to the application and other factors.

[0106] The aforementioned opposing substrate is made of a material that is easily wetted by solder, including at least one selected from copper, gold, platinum, palladium, silver, zinc, iron, tin, nickel, magnesium, indium, and alloys thereof.

[0107] There are no particular limitations on the average thickness of the aforementioned opposing substrates, which can be appropriately selected according to the purpose.

[0108] The aforementioned opposing substrate can be the heat dissipation module itself in the heat dissipation structure.

[0109] <Other Components>

[0110] As for other components, there are no particular restrictions, and they can be appropriately selected according to the purpose. Examples include intermediate layers and protective layers.

[0111] (Manufacturing method of laminated bodies)

[0112] The method for manufacturing the laminate of the present invention includes a thermally conductive layer forming step, and may further include other steps as needed.

[0113] <Heat-conducting layer formation process>

[0114] The above-mentioned thermal conductive layer forming process is a process of forming a thermal conductive layer on a substrate, which contains metal-coated resin particles separated and arranged at predetermined intervals, and includes a curing component, a curing agent for curing the curing component, thermal conductive particles, and low-melting-point metal particles.

[0115] The aforementioned substrate comprises at least one selected from silicon, aluminum, tungsten, molybdenum, glass, molding resin, stainless steel, and ceramics.

[0116] The metal-coated resin particles described above are the same as those contained in the thermally conductive layer, and their description is omitted. Furthermore, the curing components, curing agents, the first thermally conductive particles, and the low-melting-point metal particles described above are the same as those contained in the thermally conductive layer, and their description is omitted.

[0117] As a method for forming a thermally conductive layer comprising the aforementioned metal-coated resin particles arranged at predetermined intervals, for example, a mold is prepared to form recesses corresponding to the arrangement pattern of the metal-coated resin particles. Metal-coated resin particles are filled into the recesses of the mold, and a thermally conductive layer containing a curing component, a curing agent for curing the curing component, thermally conductive particles, and low-melting-point metal particles, formed on a release film, is adhered thereon to press the metal-coated resin particles into place. Thus, by rotating the metal-coated resin particles in a predetermined pattern on the thermally conductive layer, a thermally conductive film in which the metal-coated resin particles are arranged at predetermined intervals can be formed. This thermally conductive film can be, as needed, made into an insulating adhesive layer that supports the adhesion of the release film to the metal-coated resin particle arrangement layer, resulting in a two-layer thermally conductive film.

[0118] By pressing a thermally conductive film onto a substrate in such a way that metal-coated resin particles are in contact, a thermally conductive layer containing metal-coated resin particles separated and arranged at predetermined intervals can be formed.

[0119] The aforementioned thermally conductive film, for example, can be manufactured by applying a thermally conductive composition containing a curing component, a curing agent for curing the curing component, thermally conductive particles, and low-melting-point metal particles onto a release film and then curing it.

[0120] Examples of methods for applying the above-mentioned thermally conductive composition to the release film include inkjet printing, blade coating, gravure coating, gravure offset coating, bar coating, roller coating, knife coating, air knife coating, comma coating, U-comma coating, AKKU coating, smooth coating, micro-gravure coating, reverse roller coating, 4-roller coating, 5-roller coating, dip coating, curtain coating, sliding coating, and mold coating.

[0121] <Other Processes>

[0122] As for other processes, there are no special restrictions, and they can be selected appropriately according to the purpose.

[0123] Here, embodiments of the laminated body of the present invention will be described in detail with reference to the accompanying drawings. Furthermore, in each drawing, the same reference numerals are used for the same constituent parts, and repeated descriptions are sometimes omitted. Moreover, the number, position, shape, etc., of the constituent members described below are not limited to the form of this embodiment; preferred numbers, positions, shapes, etc., can be derived based on the implementation of the present invention.

[0124] <First Embodiment>

[0125] Figure 1AThis is a schematic diagram showing an example of the laminate according to the first embodiment before pressing. The laminate 10 in FIG1 has a state on a substrate 11 in which metal-coated resin particles 15 are separated and arranged at predetermined intervals, and contains a curing component, a curing agent for curing the curing component, thermally conductive particles and low-melting-point metal particles, and a counter substrate 14 on the thermally conductive layer 13.

[0126] The metal-coated resin particles 15 are in contact with the substrate 11, and the volume average particle size of the metal-coated resin particles is smaller than the volume average particle size of the thermally conductive particles. Preferably, at least a portion of the metal-coated resin particles 15 is exposed from the thermally conductive layer 13.

[0127] Figure 1B This is a schematic diagram showing an example of the laminate according to the first embodiment before pressing. When the laminate is pressed, the metal-coated resin particles 15 deform, and the adhesive component in the thermally conductive layer melts and reaches the surface of the substrate, thereby improving the adhesion between the substrate 15 and the thermally conductive layer 13.

[0128] The laminate of the present invention, for example, can be adapted to form a power LED module or power IC module by connecting a heat-dissipating substrate, an LED chip or an IC chip, to a heat sink, thereby filling the tiny gap between a heat source such as an LSI and a heat sink, where heat flows smoothly between the two.

[0129] Here, as a power LED module, there are modules with wire bonding implementation type and modules with flip chip implementation type; as a power IC module, there are modules with wire bonding implementation type.

[0130] The heat-generating structure used in this invention consists of a heating element, the laminate of this invention, and a heat-generating component.

[0131] There are no particular restrictions on the heat source mentioned above; it can be appropriately selected according to the purpose. Examples include electronic components such as CPU (Central Processing Unit), MPU (Micro Processing Unit), and GPU (Graphics Processing Unit).

[0132] As for the aforementioned heat-releasing component, if it is a structure that releases heat emitted by electronic components (heat-generating elements), there are no particular restrictions, and it can be appropriately selected according to the purpose. Examples include heat dissipation modules, heat sinks, heat spreaders, heat pipes, etc.

[0133] The aforementioned heat dissipation module is a component used to efficiently conduct heat from the aforementioned electronic components to other components. There are no particular limitations on the material used for the heat dissipation module; it can be appropriately selected depending on the purpose. Examples include copper and aluminum. The aforementioned heat dissipation module is typically in the shape of a flat plate.

[0134] The aforementioned heat sink is a component used to dissipate heat from the aforementioned electronic components into the air. There are no particular limitations on the material of the heat sink; it can be appropriately selected depending on the purpose, and examples include copper and aluminum. The aforementioned heat sink, for example, has multiple fins. The aforementioned heat sink, for example, has a base and multiple fins arranged such that they extend in a non-parallel direction (e.g., an orthogonal direction) relative to one surface of the base.

[0135] The aforementioned heat dissipation module and heat sink are generally solid structures without internal space.

[0136] The aforementioned vapor chamber is a hollow structure. The internal space of the hollow structure is filled with a volatile liquid. Examples of vapor chambers include those with a hollow structure, such as those with a hollow heat dissipation module or a plate-shaped hollow structure with a hollow heat sink.

[0137] The aforementioned heat pipe is a hollow structure in the shape of a cylinder, a roughly cylindrical shape, or a flat cylindrical shape. The internal space of the aforementioned hollow structure is filled with a volatile liquid.

[0138] here, Figure 2 This is a schematic cross-sectional view showing an example of a semiconductor device as a heat-dissipating structure. The laminate 7 of the present invention dissipates heat emitted by electronic components 3, such as semiconductor modules. Figure 2 As shown, the main surface 2a, which is fixed to the heat dissipation module 2 and faces the electronic component 3, is held between the electronic component 3 and the heat dissipation module 2. Furthermore, the heat-conducting sheet 1 is held between the heat dissipation module 2 and the heat sink 5.

[0139] The heat dissipation module 2 is formed, for example, in the shape of a square plate, having a main surface 2a facing the electronic component 3, and a sidewall 2b erected along the outer periphery of the main surface 2a. A heat-conducting plate 1 is provided on the main surface 2a surrounded by the sidewall 2b, and a heat sink 5 is provided on the opposite side 2c of the main surface 2a via the heat-conducting plate 1. The higher the thermal conductivity of the heat dissipation module 2, the lower the thermal resistance, and the more efficiently it absorbs heat from the electronic component 3, such as the semiconductor assembly. For example, it can be formed using copper or aluminum, which have good thermal conductivity.

[0140] Electronic component 3, for example, is a semiconductor component such as a BGA, and is mounted on the wiring substrate 6. In addition, in the heat dissipation module 2, the front end face of the sidewall 2b is mounted on the wiring substrate 6, thereby surrounding the electronic component 3 at a predetermined distance through the sidewall 2b.

[0141] Furthermore, by providing the laminate 7 of the present invention on the main surface 2a of the heat dissipation module 2, the heat emitted by the electronic component 3 is absorbed, thereby forming a heat-dissipating component that is heated by the heat sink 5.

[0142] Example

[0143] The following describes embodiments of the present invention, but the present invention is not limited by these embodiments.

[0144] (Example 1)

[0145] <Preparation of thermally conductive compositions>

[0146] The composition and content described in Example 1 of Table 1 were uniformly mixed using a stirring device (Rentaro Bubble Mixer, Automatic Rotary Mixer, THINKY Co., Ltd.) to prepare the thermally conductive composition of Example 1. Note that the content of each component in Table 1 is in parts by weight.

[0147] <Fabrication of Thermal Conductive Film>

[0148] The thermally conductive composition of Example 1 was applied to a release film (PET38GS, manufactured by LINTEC Corporation) by bar coating, heated at 80°C for 15 minutes, and dried to produce a thermally conductive film with an average thickness of 100 μm.

[0149] <Fabrication of a film-like master mold with metal-coated resin particles>

[0150] First, the master mold used in the embodiment is fabricated as follows. A 2mm thick nickel plate is prepared, and within a 50cm square area, hexagonal grid-patterned cylindrical protrusions (outer diameter 4μm, height 4μm, center-to-center distance 6μm) are formed, resulting in a protrusion surface density of 32,000 per mm². 2 The transfer body master mold.

[0151] Next, a polyethylene terephthalate (PET) substrate film with a width of 50 cm and a thickness of 50 μm is prepared. On the PET substrate film, a photocurable resin composition containing 100 parts by weight of acrylate resin (M208, manufactured by Toa Synthetic Co., Ltd.) and 2 parts by weight of photopolymerization initiator (IRGACURE184, manufactured by BASF Japan Co., Ltd.) is coated to make the film thickness 30 μm.

[0152] For the obtained photocurable resin composition film, a nickel-made transfer mold is pressed from its convex surface, and a high-pressure mercury lamp (1,000 mJ / cm²) is used. 2A photocurable resin layer is formed by irradiating the PET substrate film side with light, thereby creating a transfer mold where the raised portions of the transfer mold serve as recesses. This operation is repeated continuously while aligning the transfer mold along its length to obtain a film-like mold of approximately 10 μm in size, where the raised portions of the transfer mold serve as recesses. In the resulting film-like mold, the recesses of the transfer mold corresponding to the raised portion pattern are arranged in a hexagonal grid pattern.

[0153] Next, gold-plated resin particles 1 (manufactured by Sekisui Chemicals Co., Ltd., AUL703, volume average particle size 3 μm) were prepared as metal-plated resin particles, and these gold-plated resin particles were repeatedly dispersed on the surface of the film-shaped master mold. Then, the gold-plated resin particles were wiped with a cloth, thereby filling the recesses of the film-shaped master mold, which was cut 30 cm along its length, with gold-plated resin particles. Here, since there are unfilled gold-plated resin particles in the resin mold, by adjusting the number of dispersed gold-plated resin particles or the number of dispersions, areas where the gold-plated resin particles are in a predetermined ejection state are obtained.

[0154] <Transfer of gold-plated resin particles to the thermal conductive film>

[0155] Next, on a cut film-shaped master mold filled with gold-plated resin particles under predetermined conditions, the aforementioned thermally conductive film is aligned and coated with the master mold in a manner that ensures uniform length in the longitudinal direction and includes the vicinity of the center portion of the master mold in the width direction. This is done by pressing at 60°C and 0.5 MPa to transfer the metal-plated resin particles. Furthermore, an insulating resin layer is peeled off from the master mold, and the metal-plated resin particles arranged on the thermally conductive film are pressed (pressing conditions: 60°C~70°C, 0.5 MPa) to force them into the thermally conductive film. This process is performed at 5 points on the cut film-shaped master mold, thereby creating a thermally conductive film with gold-plated resin particles embedded in its arrangement.

[0156] <Creating Layered Bodies>

[0157] Between a 30mm×30mm×2mm substrate (silicon) and a 30mm×30mm×2mm opposing substrate (copper), a thermally conductive film is embedded in a state where gold-plated resin particles are arranged so that the gold-plated resin particles are in contact with the substrate. The film is heated at 150°C for 60 minutes and cured to produce the laminate of Example 1.

[0158] (Example 2)

[0159] In Example 1, the gold-plated resin particles 1 (manufactured by Sekisui Chemicals Co., Ltd., AUL703, volume average particle size 3 μm) were replaced with nickel-plated resin particles (manufactured by Sekisui Chemicals Co., Ltd., Micropearl Ni plating, volume average particle size 3 μm). Otherwise, the same procedure as in Example 1 was followed to produce the laminate of Example 2.

[0160] (Example 3)

[0161] In Example 1, gold-plated resin particles 1 (manufactured by Sekisui Chemicals Co., Ltd., AUL703, volume average particle size 3 μm) were replaced with gold-plated resin particles 2 (manufactured by Nippon Chemical Industry Co., Ltd., Arimitsu 26GNR series, volume average particle size 3 μm). Otherwise, the same procedure as in Example 1 was followed to produce the laminate of Example 3.

[0162] (Example 4)

[0163] In Example 1, the gold-plated resin particles 1 (manufactured by Sekisui Chemicals Co., Ltd., AUL703, volume average particle size 3 μm) were replaced with silver-plated resin particles (manufactured by Mitsubishi Materials Electronics & Chemicals Co., Ltd., silver coating powder series, volume average particle size 3 μm). Otherwise, the same procedure as in Example 1 was followed to produce the laminate of Example 4.

[0164] Regarding the laminate of Example 4, a cross-sectional SEM image of the location where the thermally conductive layer meets the substrate is shown in [image description missing]. Figure 3 .Depend on Figure 3 It can be seen that the silver-coated resin particles on the surface where the thermally conductive layer contacts the substrate are arranged at predetermined intervals.

[0165] (Comparative Example 1)

[0166] In Example 1, gold-plated resin particles (manufactured by Sekisui Chemicals Co., Ltd., AUL703, volume average particle size 3 μm) were replaced with unplated resin particles (manufactured by Sekisui Chemicals Co., Ltd., MicropearlSP, volume average particle size 3 μm). Otherwise, the same procedure as in Example 1 was followed to produce the laminate of Comparative Example 1.

[0167] (Comparative Example 2)

[0168] In Example 1, the transfer of the gold-plated resin particles to the thermally conductive film was not performed. Otherwise, the same procedure as in Example 1 was followed to produce the laminate of Comparative Example 2.

[0169] (Comparative Example 3)

[0170] In Example 1, the thermally conductive composition described in Comparative Example 3 as shown in Table 2 was modulated, and a thermally conductive film formed using the thermally conductive composition was used. Otherwise, the same procedure as in Example 1 was followed to produce the laminate of Comparative Example 3.

[0171] Next, the thermal conductivity of each of the resulting laminates was evaluated as follows. The results are shown in Tables 1 and 2.

[0172] Thermal conductivity

[0173] For each obtained laminate, the thermal resistance (°C·cm) was measured according to the method of ASTM-D5470. 2 / W). From the result, the thermal resistance of the cured product is calculated by subtracting the thermal resistance of the substrate and the opposing substrate. The thermal conductivity (W / m·K) is obtained from the above thermal resistance and the thickness of the cured product. The thermal conductivity is evaluated by the following criteria.

[0174] Evaluation Criteria

[0175] ◎: Thermal conductivity above 20 W / m·K

[0176] 〇: Thermal conductivity is above 10 W / m·K and less than 20 W / m·K

[0177] ×: Thermal conductivity less than 10 W / m·K

[0178] [Table 1]

[0179]

[0180] [Table 2]

[0181]

[0182] Details of each component in Tables 1 and 2 are as follows.

[0183] -Fixed components-

[0184] *OXBP: Manufactured by Ube Industries, Ltd., 4,4'-bis[(3-ethyl-3-oxetane)methoxymethyl]biphenyl

[0185] -Curing agent-

[0186] *Polycarboxylic acid: Dexerials Co., Ltd. synthetic product

[0187] -Low melting point metal particles (solder particles)-

[0188] *Sn 42 Bi 58 Manufactured by Mitsui Metals & Minerals Co., Ltd., volume average particle size Dv: 4μm, melting point 139℃ - thermally conductive particles -

[0189] * Thermally conductive particles 1: Ag-coated Cu particles, manufactured by Fukuda Metal Foil Powder Industry Co., Ltd., with a volume average particle size Dv of 40 μm.

[0190] * Thermally conductive particles 2: Ag particles: Manufactured by DOWA Electronics Co., Ltd., volume average particle size Dv: 1 μm - Arranged particles -

[0191] * Gold-plated resin particles 1: Sekisui Chemicals Co., Ltd., AUL703, volume average particle size 3μm

[0192] * Gold-plated resin particles 2: Manufactured by Nippon Chemical Industries, Ltd., Arimitsu 26GNR series, volume average particle size Dv: 3μm

[0193] * Nickel-plated resin particles: Manufactured by Sekisui Chemicals Co., Ltd., Micropearl Ni plating, volume average particle size 3μm

[0194] *Silver-coated resin particles: Manufactured by Mitsubishi Materials Electronics & Chemicals Co., Ltd., silver coating powder series, volume average particle size 3μm

[0195] * Non-metal-plated resin particles: Sekisui Chemicals Co., Ltd., MicropearlSP, volume average particle size 3μm

[0196] -polymer-

[0197] *M1276: Manufactured by Arkema Corporation, a polyamide compound.

[0198] Industry availability

[0199] The laminate of the present invention can achieve high thermal conductivity as a thermal interface material (TIM), and is therefore suitable for use, for example, in the peripherals of various electrical devices such as CPUs, MPUs, power transistors, LEDs, and laser diodes, where temperature can adversely affect the efficiency and lifespan of component operation.

[0200] This application asserts priority based on Japan Patent Application No. 2022-93012 filed with the Japan Patent Office on June 8, 2022, and incorporates all the contents set forth in the aforementioned application.

[0201] Symbol Explanation

[0202] 1. Thermal conductive sheet

[0203] 2. Heat dissipation module

[0204] 2a Main face

[0205] 3. Heating element (electronic component)

[0206] 3a above

[0207] 5. Heat sink

[0208] 6 Wiring board

[0209] 7-layered structure

[0210] 10-layer stack

[0211] 11 Substrate

[0212] 13 Thermal conductive layer

[0213] 14 Opposite substrates

[0214] 15 Metal-coated resin particles

[0215] 16 thermally conductive particles

Claims

1. A laminated body, characterized in that, have: Substrate, and The substrate contains metal-coated resin particles spaced apart and arranged at predetermined intervals, and includes a thermally conductive layer comprising a curing component, a curing agent for curing the curing component, thermally conductive particles, and low-melting-point metal particles. The metal-coated resin particles are in contact with the substrate, and the volume average particle size of the metal-coated resin particles is smaller than the volume average particle size of the thermally conductive particles. The substrate comprises at least one material selected from silicon, aluminum, tungsten, molybdenum, glass, molding resin, stainless steel, and ceramics. The low-melting-point metal particles have a melting point lower than the thermosetting temperature of the thermally conductive composition, and the low-melting-point metal particles react with the thermally conductive particles under the thermosetting conditions of the thermally conductive composition to form an alloy exhibiting a higher melting point compared to the low-melting-point metal particles. The volume average particle size of the thermally conductive particles is larger than that of the low-melting-point metal particles.

2. The laminated body according to claim 1, The metal-coated resin particles came into contact with a portion of the thermally conductive particles contained in the thermally conductive layer.

3. The laminate according to claim 1 or 2, The ratio (A:B) of the volume average particle size A of the metal-coated resin particles to the volume average particle size B of the thermally conductive particles is 1:2 to 1:

20.

4. The laminate according to claim 1 or 2, The volume average particle size of the metal-coated resin particles is between 0.3 μm and 30 μm.

5. The laminate according to claim 1 or 2, The volume average particle size of the thermally conductive particles is between 1 μm and 100 μm.

6. The laminate according to claim 1 or 2, The metal-coated resin particles are selected from at least one of gold-plated resin particles, silver-plated resin particles, copper-plated resin particles, and nickel-plated resin particles.

7. The laminate according to claim 1 or 2, The thermally conductive particles are at least any one of copper particles, silver-coated particles, and silver particles.

8. The laminate according to claim 1 or 2, The low-melting-point metal particles are solder particles containing Sn and at least one selected from Bi, Ag, Cu and In.

9. The laminate according to claim 1 or 2, The curing component is at least one of an ethylene oxide cyclic compound and an oxobutane compound.

10. The laminate according to claim 1 or 2, The thermally conductive layer has a counter substrate opposite to the substrate. The opposing substrate comprises at least one selected from copper, gold, platinum, palladium, silver, zinc, iron, tin, nickel, magnesium, indium, and alloys thereof.

11. A method for manufacturing the laminate according to claim 1, characterized in that, Includes the following processes: A thermally conductive layer forming process is performed on a substrate, comprising a thermally conductive layer containing metal-coated resin particles separated and arranged at predetermined intervals, and including a curing component, a curing agent for curing the curing component, thermally conductive particles, and low-melting-point metal particles. The substrate comprises at least one selected from silicon, aluminum, tungsten, molybdenum, glass, molding resin, stainless steel, and ceramics.

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