Laminate and method for manufacturing laminate

Abstract

To provide a laminate that has both high thermal conductivity and adhesiveness and has drop impact resistance.SOLUTION: A laminate includes a substrate 11 and a first thermally conductive layer 12 provided on the substrate, the first thermally conductive layer includes a protruding portion 12p in contact with at least a portion of a side surface of the substrate, and an interface height Y of the protruding portion relative to the side surface of the substrate, where X is the average thickness of the substrate, is greater than 0 and less than or equal to X / 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a laminate and a method for manufacturing the laminate.

Background Art

[0002] With the miniaturization of electronic devices such as power modules, image sensors, and high-performance computing (HPC), and the increase in the amount of information processing, the problem of heat generation has become more prominent, and the importance of heat diffusion from the heat source has increased. In LSIs and the like in various electronic devices, if the LSI itself is exposed to high temperatures for a long time due to the heat generation of the elements used, there is a risk of malfunction or failure. For this reason, heat conduction materials are widely used to prevent the temperature rise of LSIs and the like. The heat conduction material can prevent the temperature rise of the device by diffusing the heat generated by the element or transmitting it to a heat dissipation member for discharging it to the outside of the system such as the atmosphere.

[0003] Heretofore, a heat conduction sheet in which graphite layers containing anisotropic graphite particles are laminated and each graphite layer is bonded by a resin layer has been reported (see, for example, Patent Document 1). In addition, a thermally conductive insulating sheet containing a thermally conductive insulating filler and an uncured product and / or semi-cured product of a binder resin that is a thermosetting resin and having a thickness of 25 μm or more has been reported (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the thermal conductive sheet described in the conventional Patent Document 1, since the graphite layer has anisotropy and further includes a resin layer, the heat conduction path is limited, resulting in insufficient thermal conductivity and poor adhesion between the graphite and the metal. Further, in the thermally conductive insulating sheet described in the conventional Patent Document 2, there is a problem that it has insulation properties and insufficient thermal conductivity.

[0006] An object of the present invention is to solve the above-described problems and achieve the following objects. That is, an object of the present invention is to provide a laminate that can achieve both high thermal conductivity and adhesiveness and has impact resistance against dropping.

Means for Solving the Problems

[0007] Means for solving the above problems are as follows. That is, <1> a base material, a first thermal conductive layer provided on the base material, and the first thermal conductive layer has an overhanging portion that contacts at least a part of the side surface of the base material, a laminate characterized in that when the average thickness of the base material is X, the interface height Y of the overhanging portion with respect to the side surface of the base material is greater than 0 and less than or equal to X / 2. <2> The laminate according to <1>, wherein the interface height Y of the overhanging portion with respect to the side surface of the base material is X / 10 or more and X / 3 or less. <3> When the length of the base material in cross-sectional view is L1 and the length of the first thermal conductive layer is L2, the laminate according to <1> or <2> that satisfies the following formula: L1 < L2. <4> The laminate according to any one of <1> to <3>, wherein the base material is a silicon base material. <5> The laminate according to any one of <1> to <4>, wherein the first thermal conductive layer contains a curing component, a curing agent, and a thermal conductive material. <6> The laminate according to <5>, wherein the thermal conductive material is at least one metal filler selected from silver particles, copper particles, silver-coated copper particles, and copper-coated silver particles. <7> The laminate according to <5> or <6> above, wherein the volume filling rate of the heat conductive material is 30% by volume or more and 90% by volume or less. <8> The laminate according to any one of <5> to <7> above, further comprising a second heat conductive layer provided on the first heat conductive layer and containing a second curing component, a second curing agent, a second heat conductive material, and a low melting point metal. <9> The laminate according to any one of <5> to <8> above, wherein the first heat conductive layer further contains a polymer having at least one structure selected from a phenoxy structure, a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, a polyamide structure, and a polycarbonate structure in the molecule. <10> A step of applying the first thermally conductive composition according to claim 1 or 2 onto a substrate so as to have an overhang portion in contact with at least a part of the side surface of the substrate, A step of heating the first thermally conductive composition, and including, A method for manufacturing a laminate, characterized in that when the average thickness of the substrate is X, the interface height Y of the overhang portion with respect to the side surface of the substrate is greater than 0 and less than or equal to X / 2.

Advantages of the Invention

[0008] According to the present invention, the above-described various problems in the prior art can be solved, the above object can be achieved, a laminate having both high thermal conductivity and adhesiveness and having drop impact resistance can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

MODE FOR CARRYING OUT THE INVENTION

[0010] (Laminate) The laminate of the present invention has a base material and a first heat conduction layer, and preferably further has a second heat conduction layer, and further has a counter base material and other members as required.

[0011] Here, embodiments of the laminate of the present invention will be described in detail with reference to the drawings. In each drawing, the same reference numerals are given to the same constituent parts, and redundant descriptions may be omitted. Also, the number, position, shape, etc. of the following constituent members are not limited to the present embodiment, and may be the preferred number, position, shape, etc. for carrying out the present invention.

[0012] FIG. 1 is a schematic view showing an example of the laminate according to the first embodiment. The laminate 10 shown in FIG. 1 has a first heat conduction layer 12 containing a heat conduction material 12b on a base material 11, and has a counter base material 15 on the first heat conduction layer 12. The first heat conduction layer 12 has an overhanging portion 12p that contacts at least a part of the side surface of the base material 11.

[0013] FIG. 2 is a schematic view showing an example of the laminate according to the second embodiment. The laminate 20 shown in FIG. 2 is a second embodiment having a second heat conduction layer with respect to the laminate 10 shown in FIG. 1. On the base material 11, there is a first heat conduction layer 12 containing a heat conduction material 12b, and on the first heat conduction layer 12, there is a second heat conduction layer 14 containing second heat conductive particles 14b and a low melting point metal 14d. On the second heat conduction layer 14, there is a counter base material 15. The first heat conduction layer 12 has an overhanging portion 12p that contacts at least a part of the side surface of the base material 11.

[0014] The shape of the overhanging portion 12p will be described. In FIG. 1, reference symbol X indicates the average thickness of the base material 11, reference symbol Y indicates the interface height of the overhanging portion 12p with respect to the side surface of the base material 11, reference symbol L1 indicates the length of the base material when the laminate 10 is viewed in cross section, and reference symbol L2 indicates the length of the first heat conduction layer when the laminate 10 is viewed in cross section. The interface height Y of the overhanging portion 12p with respect to the side surface of the base material 11 with respect to the average thickness X of the base material 11 is greater than 0 and less than or equal to X / 2. In the laminate 10 shown in FIG. 1, the case of Y = X / 2 (corresponding to Example 1) is shown.

[0015] FIG. 3 is a schematic view showing another example of the laminate according to the first embodiment. The laminate 30 shown in FIG. 3 is an embodiment in which the shape of the overhanging portion of the laminate 10 in FIG. 1 is changed. In the laminate 30 shown in FIG. 3, the case of Y = X / 3 (corresponding to Example 2) is shown. Also, the relationship between the length L1 of the base material 11 and the length L2 of the first heat conduction layer 12 preferably satisfies the following formula: L1 < L2. In FIGS. 1 to 3, the case where L1 < L2 < L1 + X is satisfied is shown.

[0016] On the other hand, FIGS. 4 to 6 are schematic views showing the laminates of Comparative Examples 1 to 3. As shown as Comparative Examples 1 to 3 in the examples described later, when the interface height Y of the overhanging portion 12p with respect to the side surface of the base material 11 with respect to the average thickness X of the base material 11 does not satisfy being greater than 0 and less than or equal to X / 2, the effects of the present invention cannot be obtained. The laminate of Comparative Example 1 shown in FIG. 4 has no overhanging portion 12p, Y = 0, and L1 = L2. The laminate of Comparative Example 2 shown in FIG. 5 has no overhanging portion 12p, Y = 0, and L1 > L2. The laminate of Comparative Example 3 shown in FIG. 6 has an overhanging portion 12p, but Y = X. In any case, the interface height Y of the overhanging portion 12p does not satisfy Y > 0 and Y ≤ X / 2, which is an aspect of the comparative example.

[0017] <Base material> There are no particular restrictions on the shape, structure, size, material, etc. of the base material, and it can be appropriately selected according to the purpose. Examples of the shape of the base material include plate shape and sheet shape. Examples of the structure of the base material include single-layer structure and laminated structure. The size of the base material can be appropriately selected according to the application and the like.

[0018] Examples of the material of the base material preferably include silicon, aluminum, tungsten, molybdenum, glass, mold resin, stainless steel, ceramics, etc. Examples of the ceramics include aluminum nitride, silicon carbide, alumina, gallium nitride, etc. Examples of the mold resin include epoxy resin, silicone resin, urethane resin, acrylic resin, etc. The base material is preferably a silicon substrate.

[0019] There are no particular restrictions on the average thickness of the base material, and it can be appropriately selected according to the purpose. The base material may be the heat-generating body (electronic component) itself in the heat dissipation structure.

[0020] <First heat conduction layer> The first heat conduction layer has an overhanging portion that contacts at least a part of the side surface of the base material. The first heat conduction layer is preferably formed on the base material and has a main body portion formed in contact with the base material and the overhanging portion formed integrally with the main body portion. As the side surface of the base material in contact with the protruding portion, it may be a pair of opposing side surfaces, two or more pairs of opposing side surfaces, or all side surfaces, and can be appropriately selected according to the embodiment, the shape of the base material, and the purpose.

[0021] [Shape of the protruding portion] When the average thickness of the base material is X, the interface height Y of the protruding portion with respect to the side surface of the base material is greater than 0 and less than or equal to X / 2, and preferably greater than or equal to X / 10 and less than or equal to X / 3. When the laminate has a protruding portion and the interface height Y of the protruding portion with respect to the side surface of the base material is greater than 0 and less than or equal to X / 2, in addition to the lamination surface with the first heat conductive layer in the base material, the first heat conductive layer also contacts the side surface of the base material, thereby improving the thermal conductivity. Also, the adhesiveness of the laminate can be improved, and the drop impact resistance can be improved.

[0022] Also, when the length of the base material in cross-sectional view is L1 and the length of the first heat conductive layer is L2, it is preferable to satisfy the following formula: L1 < L2, and more preferably to satisfy the following formula: L1 < L2 < L1 + X. By satisfying L1 < L2, the adhesiveness of the laminate can be improved, and the drop impact resistance can be improved.

[0023] The first heat conductive layer preferably contains a curing component, a curing agent, and a heat conductive material, more preferably further contains low melting point metal particles and a specific polymer, and further contains other components as necessary.

[0024] - Curing component - As the curing component, it is preferable to use at least one of an oxirane ring compound and an oxetane compound.

[0025] -- Oxirane ring compound -- The oxirane ring compound is a compound having an oxirane ring, and examples thereof include epoxy resins. The epoxy resin is not particularly limited and can be appropriately selected according to the purpose. For example, glycidyl ether type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A type epoxy resin, tris-phenol type epoxy resin, tetra-phenol 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, etc. can be mentioned. These may be used alone or in combination of two or more.

[0026] --Oxetane compound-- 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.

[0027] The oxetane compound is not particularly limited and can be appropriately selected according to the purpose. For example, 3,7-bis(3-oxetanyl)-5-oxa-nonane, 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-oxetanylmethoxy)hexane, 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-ethyloxetan-3-yl)methoxy]methyl}oxetane, xylylene bisoxetane, 4,4′-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl (OXBP), isophthalic acid bis[(3-ethyl-3-oxetanyl)methyl]ester (OXIPA), etc. can be mentioned. These may be used alone or in combination of two or more.

[0028] As the oxetane compound, commercially available products can be used. Examples of the commercially available products include the "ARON OXETANE (registered trademark)" series sold by Toagosei Co., Ltd., the "ETERNACOLL (registered trademark)" series sold by Ube Industries, Ltd., etc.

[0029] Among the oxirane ring compounds and oxetane compounds, glycidyl ether type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, phenol-dicyclopentadiene type epoxy resins, bisphenol A type epoxy resins, aliphatic epoxy resins, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl (OXBP), isophthalic acid bis[(3-ethyl-3-oxetanyl)methyl]ester (OXIPA) are preferable.

[0030] The content of the curing component is not particularly limited and can be appropriately selected according to the purpose. However, it is preferably 0.5% by mass or more and 60% by mass or less based on the total amount of the thermally conductive composition for forming the first thermally conductive layer.

[0031] - Curing agent - The curing agent is a curing agent corresponding to the curing component, and examples thereof include polyfunctional carboxylic acids, acid anhydride-based curing agents, aliphatic amine-based curing agents, aromatic amine-based curing agents, phenol-based curing agents, mercaptan-based curing agents and other polyaddition-type curing agents, and catalyst-type curing agents such as imidazole. These may be used alone or in combination of two or more.

[0032] When the curing component is an epoxy resin, the acid anhydride-based curing agent is preferable because there is no gas generation during thermal curing, a long pot life can be realized when mixed with the epoxy resin, and a good balance can be achieved among the electrical properties, chemical properties, and mechanical properties of the resulting cured product. Examples of the acid anhydride-based curing agent include cyclohexane-1,2-dicarboxylic anhydride, and monoacid anhydrides of tricarboxylic acids. Examples of the monoacid anhydride of tricarboxylic acid include cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride.

[0033] The curing agent having flux activity is preferable in terms of improving the wettability of the molten low melting point metal particles with respect to the thermally conductive particles. Examples of methods for imparting flux activity to the hardener include, for example, a method of introducing a protonic acid group such as a carboxy group, a sulfonyl group, or a phosphoric acid group into the hardener by a known method. Among these, from the viewpoint of reactivity with an epoxy resin or an oxetane compound as a curing component, it is preferable to introduce a carboxy group, and examples thereof include polyvalent carboxylic acids containing a carboxyl group such as glutaric acid and succinic acid. Further, the hardener may be a compound modified from glutaric anhydride or succinic anhydride or a metal salt of a polyvalent carboxylic acid such as silver glutarate.

[0034] The content of the hardener is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 0.1% by mass or more and 30% by mass or less based on the total amount of the thermally conductive composition.

[0035] In one embodiment, it is preferable that the curing component is an oxetane compound and the hardener is glutaric acid from the viewpoint of achieving higher thermal conductivity.

[0036] -First Thermal Conductive Material- The thermally conductive material (hereinafter sometimes referred to as the first thermally conductive material) is not particularly limited as long as it is a material having excellent thermal conductivity and can be appropriately selected according to the purpose. Examples thereof include metal materials such as metals, metal particles, metal plates, dendritic metals, and metal wires; and non-metal materials such as carbon materials. These may be used alone or in combination of two or more.

[0037] The type of the metal material is not particularly limited and can be appropriately selected according to the purpose. From the viewpoints of thermal conductivity and safety, aluminum, aluminum oxide, aluminum nitride, boron nitride, carbon resin, nickel, iron, gold, silver, copper, zinc, and tin are preferable, and gold, silver, copper, and nickel are more preferable. These may be used alone or in combination of two or more.

[0038] Examples of the non-metallic material include carbon materials such as particulate carbon materials and fibrous carbon materials (carbon fibers).

[0039] Among the heat conductive materials, metal materials are preferred, and it is more preferable that they are at least one metal filler selected from silver particles, copper particles, silver-coated copper particles, and copper-coated silver particles.

[0040] The shape of the heat conductive material is not particularly limited and can be appropriately selected according to the purpose. Examples include spherical, flat, granular, and needle-like shapes.

[0041] The volume filling ratio of the first heat conductive particles in the first heat conductive layer is not particularly limited and can be appropriately selected according to the purpose. From the viewpoint of increasing the filling ratio to enhance the heat conductivity, 30% by volume or more is preferable, 35% by volume or more is more preferable, and 40% by volume or more is even more preferable.

[0042] The volume average particle diameter (D 50 ) of the heat conductive particles in the first heat conductive layer is preferably 0.3 μm or more and 30 μm or less, and more preferably 0.5 μm or more and 10 μm or less. The volume average particle diameter (D 50 ) can be measured, for example, by a laser diffraction / scattering particle size distribution measuring device (product name: Microtrac MT3300EXII).

[0043] <Low melting point metal> The low melting point metal means low melting point metal particles and low melting point metal obtained by melting and solidifying the low melting point metal particles. As the low melting point metal particles, solder particles defined in JIS Z3282-1999 are preferably used.

[0044] Examples of the solder particles include Sn-Pb-based solder particles, Pb-Sn-Sb-based solder particles, Sn-Sb-based solder particles, Sn-Pb-Bi-based solder particles, Sn-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, Sn-Ag-Cu-based solder particles, etc. These may be used alone or in combination of two or more. Among these, solder particles containing Sn and at least one selected from Bi, Ag, Cu, and In are preferred, 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, and Sn-Bi-based solder particles containing Sn and Bi are even more preferred.

[0045] The shape of the low melting point metal particles is not particularly limited and can be appropriately selected according to the purpose. Examples include spherical, flat, granular, needle-like, etc. The melting point of the low melting point metal particles is preferably 100°C or higher and 250°C or lower, and more preferably 120°C or higher and 200°C or lower.

[0046] The melting point of the low melting point metal particles is preferably lower than the heating temperature of the heating step in the method for manufacturing the laminate described later. Thereby, during the curing of the first thermally conductive composition, a first thermally conductive layer in which a network (continuous phase of metal) is formed through the first thermally conductive particles by the melted low melting point metal can be formed. Therefore, a laminate excellent in heat resistance, thermal conductivity, and adhesiveness can be realized.

[0047] The volume average particle diameter of the low melting point metal particles is preferably 10 μm or less, and more preferably 1 μm or more and 7 μm or less. When the volume average particle diameter of the low melting point metal particles is 10 μm or less, the volume ratio of the low melting point metal particles to the thermally conductive particles can be reduced, and high thermal conductivity and low thermal resistance of the first thermally conductive layer can be realized. The volume average particle diameter of the low melting point metal particles can be measured in the same manner as the volume average particle diameter of the heat conductive particles.

[0048] The volume average particle diameter of the first heat conductive particles is larger than that of the low melting point metal particles, and the volume average particle diameter ratio (A / B) of the first heat conductive particles A and the low melting point metal particles B is preferably 1.2 or more, more preferably 1.5 or more. The upper limit value of the volume average particle diameter ratio (A / B) is preferably 10 or less. By using low melting point metal particles having a smaller volume average particle diameter than the first heat conductive particles, the first heat conductive particles become the main component in the first heat conductive layer composition, and the low melting point metal particles existing between the first heat conductive particles and the first heat conductive particles melt by heating and alloy with the first heat conductive particles to form a network, so that high thermal conductivity and low thermal resistance can be realized.

[0049] In the heat conductive layer composition for forming the first heat conductive layer, the volume ratio (A / B) of the first heat conductive particles A and the low melting point metal particles B is preferably 1 or more, more preferably 1.2 or more, and still more preferably 1.5 or more. The upper limit value of the volume ratio (A / B) is preferably 5 or less, more preferably 4 or less, and still more preferably 3 or less.

[0050] - Specific polymer - In order to impart flexibility and sheet properties, the heat conductive composition preferably contains a specific polymer in addition to the polymer formed from the curing component and the curing agent. As the specific polymer, a polymer having at least one structure selected from a phenoxy structure, a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, a polyamide structure, and a polycarbonate structure in the molecule is used.

[0051] Examples of the specific polymer include a phenoxy structure such as bisphenol A type and bisphenol F type, a polybutadiene structure such as polybutadiene and hydrogenated polybutadiene, a polysiloxane structure such as silicone rubber, a poly(meth)acrylate structure, a polyalkylene structure (a polyalkylene structure having 2 to 15 carbon atoms is preferred, a polyalkylene structure having 3 to 10 carbon atoms is more preferred, and a polyalkylene structure having 5 to 6 carbon atoms is even more preferred), a polyalkyleneoxy structure (a polyalkyleneoxy structure having 2 to 15 carbon atoms is preferred, a polyalkyleneoxy structure having 3 to 10 carbon atoms is more preferred, and a polyalkyleneoxy structure having 5 to 6 carbon atoms is even more preferred), a polyisoprene structure, a polyisobutylene structure, and a polycarbonate structure. It preferably has at least one structure selected from the group consisting of a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyisoprene structure, a polyisobutylene structure, and a polycarbonate structure. It preferably has at least one structure selected from the group consisting of a polybutadiene structure, a polyisoprene structure, and a polycarbonate structure.

[0052] The specific polymer preferably has a high molecular weight to exhibit flexibility. The number average molecular weight (Mn) of the specific polymer is preferably 1,000 or more and 1,000,000 or less, and more preferably 5,000 or more and 900,000 or less. The number average molecular weight (Mn) is the number average molecular weight in terms of polystyrene measured using GPC (gel permeation chromatography).

[0053] The specific polymer is preferably selected from a polymer having a glass transition temperature (Tg) of 25°C or lower and a polymer that is liquid at 25°C in order to exhibit flexibility. The glass transition temperature of the polymer having a glass transition temperature (Tg) of 25°C or lower is preferably 20°C or lower, and more preferably 15°C or lower. The lower limit of the glass transition temperature is not particularly limited and can be appropriately selected according to the purpose, but is preferably -15°C or higher. As the polymer that is liquid at 25°C, a polymer that is liquid at 20°C or lower is preferred, and a polymer that is liquid at 15°C or lower is more preferred.

[0054] From the viewpoint of improving the mechanical strength of the cured product, the specific polymer preferably has a functional group capable of reacting with the curing component. Note that the functional group capable of reacting with the curing component includes functional groups that appear upon heating. Examples of the functional group capable of reacting with the curing component include one or more functional groups selected from the group consisting of a hydroxy group, a carboxy group, an acid anhydride group, a phenolic hydroxy group, an epoxy group, an isocyanate group, and a urethane group. Among these, as the functional group, a hydroxy group, an acid anhydride group, a phenolic hydroxy group, an epoxy group, an isocyanate group, and a urethane group are preferred, and a hydroxy group, an acid anhydride group, a phenolic hydroxy group, and an epoxy group are more preferred.

[0055] The content of the specific 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 still more preferably 1% by mass or more and 20% by mass or less, based on the total amount of the thermally conductive composition.

[0056] -Other Components- 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 appropriately selected according to the purpose. Examples include additives (such as antioxidants, ultraviolet absorbers, curing accelerators, silane coupling agents, leveling agents, flame retardants, etc.).

[0057] The thermally conductive composition for forming the first thermally conductive layer can be prepared by uniformly mixing the curing component, the curing agent, and the thermally conductive material, and, if necessary, the low melting point metal particles, the specific polymer, and other components by a conventional method.

[0058] The heat-conductive composition may be either a sheet-like heat-conductive sheet or a paste-like heat-conductive paste (sometimes referred to as a heat-conductive adhesive or a heat-conductive grease). Among these, a heat-conductive sheet is preferable from the viewpoint of ease of handling, and a heat-conductive paste is preferable from the viewpoint of cost.

[0059] <Second heat-conductive layer> The second heat-conductive layer contains a second curing component, a second curing agent, a second heat-conductive material, and a second low-melting-point metal, and may further contain other components as necessary. As the second curing component, the second curing agent, the second heat-conductive material, and the second low-melting-point metal, the matters described for the curing component, the curing agent, the heat-conductive material, and the low-melting-point metal in the laminate of the present invention described above can be appropriately selected.

[0060] The average thickness of the second heat-conductive layer is not particularly limited and can be appropriately selected according to the purpose, but is preferably 20 μm or more and 300 μm or less, and more preferably 50 μm or more and 200 μm or less.

[0061] <Opposing substrate> The opposing substrate is disposed opposite to the substrate, and there are no particular restrictions on its shape, structure, size, material, etc., and it can be appropriately selected according to the purpose. Examples of the shape of the opposing substrate include a plate shape and a sheet shape. Examples of the structure of the opposing substrate include a single-layer structure and a laminated structure. The size of the opposing substrate can be appropriately selected according to the application and the like. The material of the opposing substrate is a material that is easily wetted by solder and includes at least one selected from copper, gold, platinum, palladium, silver, zinc, iron, tin, nickel, magnesium, indium, and alloys thereof. The average thickness of the opposing substrate is not particularly limited and can be appropriately selected according to the purpose. The opposing substrate may be the heat spreader itself in the heat dissipation structure.

[0062] <Other members> There are no particular restrictions on other members, and they can be appropriately selected according to the purpose. Examples include a protective layer and the like.

[0063] (Method for manufacturing a laminate) The method for manufacturing the laminate of the present invention includes a first application step and a heating step, preferably includes a second application step, and further includes other steps as necessary.

[0064] [Method for manufacturing a laminate according to the first embodiment] As one embodiment, by including the first application step and the heating step in the method for manufacturing the laminate, a laminate having a base material and a first heat conduction layer provided on the base material (the laminate according to the first embodiment) can be manufactured.

[0065] [Method for manufacturing a laminate according to the second embodiment] As another embodiment, by including the first application step, the second application step, and the heating step in the method for manufacturing the laminate, a laminate having a base material, a first heat conduction layer provided on the base material, and a second heat conduction layer provided on the first heat conduction layer (the laminate according to the second embodiment) can be manufactured.

[0066] <First application step> The first application step is a step of applying a first thermally conductive composition containing a curing component, a curing agent, and a heat conduction material onto the base material so as to have an overhanging portion in contact with at least a part of the side surface of the base material. As the curing component, curing agent, heat conduction material, and other components contained in the first thermally conductive composition, the matters described in the laminate of the present embodiment can be appropriately selected.

[0067] Examples of the method for applying the first thermally conductive composition to the substrate 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, a knife coating method, an air knife coating method, a comma coating method, a U-comma coating method, an AKKU coating method, a smoothing coating method, a microgravure coating method, a reverse roll coating method, a four-roll coating method, a five-roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, and the like. Alternatively, the first thermally conductive composition in sheet form may be applied onto the substrate by means such as transfer.

[0068] In addition, the method for adjusting the shape and size of the protruding portion is not particularly limited and can be appropriately selected according to the purpose. For example, a method of adjusting the application amount of the first thermally conductive composition (for example, the thickness of the first thermally conductive composition in sheet form or the dispense amount of the first thermally conductive composition in paste form); a method of performing a pressure bonding step before the heating step and adjusting the pressure in the pressure bonding step to adjust the protruding portion; and the like.

[0069] <Heating step> The heating step is a step of heating the thermally conductive composition, whereby a first thermally conductive layer is formed on the substrate. In the case of having a second application step described later, the heating step is a step of heating the first thermally conductive composition and the second thermally conductive composition, whereby a first thermally conductive layer and a second thermally conductive layer are formed on the substrate.

[0070] The heating conditions are not particularly limited as long as the curing component contained in the thermally conductive composition and the curing agent react and cure, and the thermally conductive material can form a thermal conduction network, and can be appropriately selected according to the purpose. For example, 120°C to 190°C, 1 minute to 30 minutes are preferable, and 140°C to 170°C, 1 minute to 10 minutes are more preferable.

[0071] <Second application step> The second application step is a step of applying a second thermally conductive composition onto the thermally conductive composition (first thermally conductive composition) applied onto the base material.

[0072] Examples of the method for applying the second thermally conductive composition onto the base material include, for example, an inkjet method, a blade coating method, a gravure coating method, a gravure offset coating method, a bar coating method, a roll coating method, a knife coating method, an air knife coating method, a comma coating method, a U comma coating method, an AKKU coating method, a smoothing coating method, a microgravure coating method, a reverse roll coating method, a four-roll coating method, a five-roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method, and the like. Alternatively, the sheet-like second thermally conductive composition may be applied onto the base material by means such as transfer.

[0073] By applying the second thermally conductive composition onto the first thermally conductive composition while in a liquid phase and then performing a heating step, the adhesiveness of the obtained first thermally conductive layer and second thermally conductive layer can be improved. Further, in the subsequent heating step, the flux activity of the curing agent is manifested, and the wettability between the dissolved low-melting metal and the thermally conductive particles can be improved.

[0074] - Second thermally conductive composition - The second thermally conductive composition contains a second curing component, a second curing agent, second thermally conductive particles, and second low-melting metal particles, and further contains other components as necessary.

[0075] - Second curing component - The second curing component preferably contains at least one of an oxetane compound and an epoxy resin, and more preferably contains an oxetane compound and an epoxy resin. As the second curing component, the oxetane compound, and the epoxy resin, the matters described in the above-mentioned curing component in the thermoplastic resin of the present invention can be appropriately selected.

[0076] In the second heat-conductive composition, the content of the second curing component is not particularly limited and can be appropriately selected according to the purpose. With respect to the total amount of the second heat-conductive composition, 0.5% by volume or more and 20% by volume or less is preferable, and 1% by volume or more and 15% by volume or less is more preferable.

[0077] -Second curing agent- The curing agent is a curing agent corresponding to the curing component, and examples thereof include polyfunctional carboxylic acids, acid anhydride-based curing agents, aliphatic amine-based curing agents, aromatic amine-based curing agents, phenolic curing agents, mercaptan-based curing agents, and other polyaddition-type curing agents, and catalyst-type curing agents such as imidazole. These may be used alone or in combination of two or more. Among these, polyfunctional carboxylic acids are preferable, and glutaric acid is preferable. As the second curing agent, the matters described in the above-described curing agent in the laminate of the present invention can be appropriately selected.

[0078] In the second heat-conductive composition, the content of the second curing agent is not particularly limited and can be appropriately selected according to the purpose. With respect to the total amount of the second heat-conductive composition, 0.5% by volume or more and 20% by volume or less is preferable, and 1% by volume or more and 15% by volume or less is more preferable.

[0079] -Second heat-conductive particles- As the second heat-conductive particles, at least one of copper particles, silver-coated particles, and silver particles is preferable, and silver-coated particles are more preferable. Examples of the silver-coated particles include silver-coated copper particles, silver-coated nickel particles, silver-coated aluminum particles, and the like. The shape of the second heat-conductive particles is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include spherical, flat, granular, and needle-like shapes.

[0080] The volume average particle diameter of the second heat conductive particles is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 70 μm or less, and still more preferably 5 μm or more and 50 μm or less. When the volume average particle diameter of the second heat conductive particles is 1 μm or more and 100 μm or less, excellent heat conductivity can be realized. The volume average particle diameter of the second heat conductive particles can be measured in the same manner as the volume average particle diameter of the heat conductive material.

[0081] - Second low melting point metal - The volume average particle diameter of the low melting point metal particles is preferably 10 μm or less, more preferably 1 μm or more and 7 μm or less. When the volume average particle diameter of the low melting point metal particles is 10 μm or less, the volume ratio of the low melting point metal particles to the second heat conductive particles can be reduced, and high heat conductivity and low thermal resistance of the second heat conductive layer can be realized. The volume average particle diameter of the low melting point metal particles can be measured in the same manner as the volume average particle diameter of the heat conductive material.

[0082] The volume average particle diameter of the second heat conductive particles is larger than the volume average particle diameter of the second low melting point metal particles, and the volume average particle diameter ratio (α / β) of the second heat conductive particles α to the second low melting point metal particles β is preferably 1.2 or more, more preferably 1.5 or more. The upper limit value of the volume average particle diameter ratio (α / β) is preferably 10 or less. By using low melting point metal particles having a volume average particle diameter smaller than that of the second heat conductive particles, the second heat conductive particles become the main component in the second heat conductive composition, and the low melting point metal particles existing between the second heat conductive particles and the second heat conductive particles are melted by heating and alloyed with the second heat conductive particles to form a network, so that high heat conductivity and low thermal resistance can be realized.

[0083] In the second heat conductive composition for forming the second heat conductive layer, the volume ratio (α / β) of the second heat conductive particles α to the low melting point metal particles β is preferably 1 or more, more preferably 1.5 or more, and still more preferably 1.8 or more. The upper limit value of the volume ratio (α / β) is preferably 4 or less, more preferably 3 or less.

[0084] <Other processes> There are no particular restrictions on other processes, and they can be appropriately selected according to the purpose. For example, a crimping process, a protective layer formation process, a facing substrate lamination process, etc. can be mentioned.

[0085] The laminate of the present invention and the laminate manufactured by the manufacturing method of the laminate of the present invention can be suitably used, for example, as a thermal interface material (TIM) that fills a minute gap between a heat source such as an LSI and a heat sink so that heat can flow smoothly between them, or when bonding a heat dissipation substrate on which an LED chip or an IC chip is mounted to a heat sink to form a power LED module or a power IC module. Here, as the power LED module, there are a wire bonding mounting type and a flip chip mounting type, and as the power IC module, there is a wire bonding mounting type.

[0086] (Heat dissipation structure) The heat dissipation structure of the present embodiment has a heat generating body, the laminate of the present invention described above, and a heat dissipation member, and further has other members as required.

[0087] There are no particular restrictions on the heat generating body, and it can be appropriately selected according to the purpose. For example, electronic components such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), and a GPU (Graphics Processing Unit) can be mentioned.

[0088] There are no particular restrictions on the heat dissipation member as long as it is a structure that dissipates heat generated by an electronic component (heat generating body), and it can be appropriately selected according to the purpose. For example, a heat spreader, a heat sink, a vapor chamber, a heat pipe, etc. can be mentioned. The heat spreader is a member for efficiently transferring the heat of the electronic component to other components. The material of the heat spreader is not particularly limited and can be appropriately selected according to the purpose. For example, copper, aluminum, etc. can be mentioned. The heat spreader is usually in a flat plate shape. The heat sink is a member for releasing the heat of the electronic component into the air. The material of the heat sink is not particularly limited and can be appropriately selected according to the purpose. For example, copper, aluminum, etc. can be mentioned. The heat sink has, for example, a plurality of fins. The heat sink has, for example, a base portion and a plurality of fins provided so as to extend in a non-parallel direction (for example, an orthogonal direction) with respect to one surface of the base portion. The heat spreader and the heat sink generally have a solid structure without a space inside. The vapor chamber is a hollow structure. A volatile liquid is enclosed in the internal space of the hollow structure. Examples of the vapor chamber include those in which the heat spreader has a hollow structure and plate-like hollow structures such as those in which the heat sink has a hollow structure. The heat pipe is a hollow structure in a cylindrical shape, a substantially cylindrical shape, or a flat cylindrical shape. A volatile liquid is enclosed in the internal space of the hollow structure.

[0089] Here, FIG. 7 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 dissipates the heat generated by an electronic component 3 such as a semiconductor element. As shown in FIG. 7, it is fixed to the main surface 2a of the heat spreader 2 facing the electronic component 3 and is sandwiched between the electronic component 3 and the heat spreader 2. Further, the thermal conductive sheet 1 is sandwiched between the heat spreader 2 and the heat sink 5.

[0090] The heat spreader 2 is formed, for example, in a rectangular plate shape and has a main surface 2a facing the electronic component 3 and side walls 2b erected along the outer periphery of the main surface 2a. The heat spreader 2 is provided with a thermal conduction sheet 1 on the main surface 2a surrounded by the side walls 2b, and a heat sink 5 is provided on the other surface 2c opposite to the main surface 2a via the thermal conduction sheet 1. Since the heat spreader 2 has a higher thermal conductivity, the thermal resistance decreases and it can efficiently absorb the heat of the electronic component 3 such as a semiconductor element. Therefore, it can be formed using, for example, copper or aluminum with good thermal conductivity.

[0091] The electronic component 3 is, for example, a semiconductor element such as a BGA and is mounted on the wiring board 6. Also, the heat spreader 2 has the tip end surface of the side wall 2b mounted on the wiring board 6, and thereby the side wall 2b surrounds the electronic component 3 at a predetermined distance. Then, by providing the laminate 7 of the present invention on the main surface 2a of the heat spreader 2, a heat radiating member is formed that absorbs the heat generated by the electronic component 3 and radiates heat from the heat sink 5.

Example

[0092] Hereinafter, examples of the present invention will be described, but the present invention is not limited to these examples at all.

[0093] (Example 1) <Preparation of Thermal Conductive Composition> The composition and content shown in Table 1 were uniformly mixed using a stirring device (Bubble Removing Rintaro, Automatic Revolution Mixer, manufactured by Shinky Co., Ltd.) to prepare a thermal conductive composition for forming the first thermal conductive layer.

[0094]

Table 1

[0095] <Manufacture of Laminate> Next, a first thermally conductive composition was applied onto a substrate (silicon substrate) measuring 20 mm × 20 mm × 1.00 mm. A counter substrate (copper plate plated with nickel) measuring 25 mm × 25 mm × 1.00 mm was laminated onto the applied first thermally conductive composition. Pressing was performed for 5 minutes under the conditions of an upper plate temperature of 150°C on the copper substrate side, a lower plate temperature of 150°C on the silicon substrate side, and a set air pressure of 0.11 MPa (40 psi in pressure conversion), followed by heating at 150°C for 5 minutes to cure and produce the laminate of Example 1. The laminate of Example 1 had a cross-sectional structure as shown in FIG. 1. The average thickness of the first thermally conductive layer was 99 μm, the average thickness X of the substrate was 1000 μm, the interface height Y of the protruding portion with respect to the side surface of the substrate was X / 2 (500 μm), the length L1 of the substrate when viewed in cross-section was 20 mm, and the length L2 of the first thermally conductive layer when viewed in cross-section was 20.5 mm.

[0096] (Examples 2 to 4) In Example 1, laminates of Examples 2 to 4 were each produced in the same manner as in Example 1, except that the shape of the protruding portion in the first thermally conductive layer was changed as shown in Table 2. The laminate of Example 2 had a cross-sectional structure as shown in FIG. 3.

[0097] (Examples 5 to 6) In Example 1, laminates of Examples 5 to 6 were each produced in the same manner as in Example 1, except that the average thickness X of the substrate was changed as shown in Table 2.

[0098] (Comparative Example 1) In Example 1, a laminate of Comparative Example 1 was produced in the same manner as in Example 1, except that the shape of the protruding portion in the first thermally conductive layer was changed as shown in Table 3 and FIG. 4. As shown in FIG. 4, the laminate of Comparative Example 1 did not have a protruding portion 12p, Y = 0, and L1 = L2.

[0099] (Comparative Example 2) In Example 1, laminates of Comparative Examples 1 to 3 were produced in the same manner as in Example 1, except that the shape of the protruding portion in the first thermally conductive layer was changed as shown in Table 3 and FIG. 5. As shown in FIG. 5, the laminate of Comparative Example 2 has no overhanging portion 12p, Y = 0, and L1 > L2.

[0100] (Comparative Example 3) In Example 1, laminates of Comparative Examples 1 to 3 were produced in the same manner as in Example 1, except that the shape of the overhanging portion in the first heat conductive layer was changed as shown in Table 3 and FIG. 6. As shown in FIG. 6, the laminate of Comparative Example 3 has an overhanging portion 12p, but Y = X, and Y does not satisfy Y > 0 and Y ≤ X / 2.

[0101] Next, for each of the obtained laminates, the sizes of each part were measured as follows, and "thermal conductivity", "adhesion", and "drop impact resistance" were evaluated. The results are shown in Tables 1 to 3.

[0102] <Measurement of Size> Each laminate was cut parallel to the lamination direction, the obtained cut surface was polished, the polished surface was photographed with a scanning electron microscope (S-3000N, manufactured by Hitachi, Ltd.), and from the cut surface of the laminate, the thickness X of the base material, the thickness of the first heat conductive layer, the interface height Y of the overhanging portion with respect to the side surface of the base material, the length L1 of the base material, and the length L2 of the first heat conductive layer were measured, and the average value of the measured values at arbitrarily three points was obtained. The interface height Y of the overhanging portion was shown as a relative value with respect to the thickness X of the base material. The results are shown in Tables 2 to 3.

[0103] <Thermal Conductivity> In accordance with JIS R 1611, the thermal resistance of each laminate was measured under the condition of a pulse width of 20 μsec using a flash method thermal diffusivity / thermal conductivity measuring apparatus (LFA467, manufactured by Netzsch Gerätebau GmbH). Next, the thermal resistance of the copper plate (25 mm × 25 mm, average thickness 1.00 mm) and the silicon plate (20 mm × 20 mm, average thickness 1.00 mm) plated with nickel used as the base material for the measurement was subtracted from the measured value to calculate the thermal resistance of the thermal conductive sheet. Then, the thermal conductivity W / (m·K) of the thermal conductive sheet was calculated by dividing the average thickness of the thermal conductive sheet measured in advance by the thermal resistance. The thermal conductivity was evaluated according to the following criteria. The results are shown in Tables 2 to 3. [Evaluation Criteria] ◎: The thermal conductivity is 20 W / m·K or more. 〇: The thermal conductivity is 15 W / m·K or more and less than 20 W / m·K. △: The thermal conductivity is 10 W / m·K or more and less than 15 W / m·K. ×: The thermal conductivity is less than 10 W / m·K.

[0104] [Adhesion] [Preparation of Laminated Body after Pressing] Each laminated body was sandwiched between a nickel-plated copper plate (nickel-plated copper plate, 25 mm × 25 mm, average thickness 1.00 mm) and a silicon plate (20 mm × 20 mm, average thickness 1.00 mm), and heated and pressed for 5 minutes under the conditions of an upper plate temperature of 150°C on the copper plate side, a lower plate temperature of 150°C on the silicon plate side, and a set air pressure of 0.11 MPa (40 psi in pressure conversion) using a mini press machine. Then, heating was performed at 150°C for 1 hour in an oven (device name: Perfect Oven PHH-202, manufactured by Espec Corporation). [Accelerated Life Test and Evaluation of Adhesion] The laminated body after pressing was put into a highly accelerated life test device (device name: EHS-212MD, manufactured by Espec Corporation) at 130°C and 85% humidity for 192 hours. After the accelerated life test, each thermal conductive sheet was observed using an ultrasonic imaging device (SAT, device name: FS300IIIHR, manufactured by Hitachi Power Solutions Co., Ltd.), and the adhesion was evaluated by inspecting the adhesion to the base material and the presence or absence of voids. A 50 MHz, 7 mm probe was used on the copper plate side, and a 25 MHz probe was used on the silicon plate side. The results are shown in Tables 2 to 3. [Evaluation Criteria] ◎: The floating, peeling, and voids from the base material of the thermal conductive sheet are less than 1% in terms of the area ratio to the observation field of view. 〇: The floating, peeling, or voids from the base material of the thermal conductive sheet are less than 10% in terms of the area ratio to the observation field of view and are within the practical range. ×: The floating, peeling, or voids from the base material of the thermal conductive sheet are 10% or more in terms of the area ratio to the observation field of view and are outside the practical range.

[0105] <Impact resistance against dropping> The impact resistance against dropping of each laminate was evaluated by the presence or absence of dropping of fragments of the first heat conduction layer when random vibration was applied using a vibration test apparatus (G-5230NS, manufactured by Shinku Kenkyusho Co., Ltd.) in accordance with JIS Z 0232. [Evaluation criteria] 〇: No dropping of fragments of the first heat conduction layer. ×: There is dropping of fragments of the first heat conduction layer.

[0106]

Table 2

[0107]

Table 3

[0108] Details of each component in Table 1 are as follows.

[0109] -Curing component- · Curing component (oxetane compound): ETERNACOLL (registered trademark) OXBP (manufactured by Ube Industries, Ltd.), 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl

[0110] -Curing agent- · Glutaric acid: manufactured by Tokyo Chemical Industry Co., Ltd., 1,3-propanedicarboxylic acid

[0111] -Low melting point metal particles (solder particles)- · Sn 58 Bi 42 : manufactured by Mitsui Mining & Smelting Co., Ltd., volume average particle diameter Dv: 6 μm, melting point 139 °C The volume average particle diameter Dv of the above low melting point metal particles is the measured value by a laser diffraction / scattering particle size distribution measuring apparatus (product name: Microtrac MT3300EXII).

[0112] -Thermally conductive particles- · Ag-coated Cu particles (Dv: 10 μm): Ag-coated Cu particles, manufactured by Fukuda Metal Foil & Powder Co., Ltd., volume average particle diameter Dv: 10 μm

[0113] - Polymer - · YP-50 (manufactured by Nippon Steel Chemical & Material Co., Ltd.), a polyhydroxy polyether synthesized from bisphenols and epichlorohydrin

Industrial Applicability

[0114] The laminate of the present invention can achieve excellent heat resistance, thermal conductivity, and adhesiveness as a thermal interface material (TIM). Therefore, for example, it is suitably used around various electric devices such as CPUs, MPUs, power transistors, LEDs, and laser diodes, where the efficiency and lifespan of element operation are adversely affected by temperature.

Explanation of Reference Numerals

[0115] 1 Thermal Conductive Sheet 2 Heat Spreader 2a Main Surface 3 Heat Generating Body (Electronic Component) 3a Upper Surface 5 Heat Sink 6 Wiring Substrate 7 Laminate 10, 20, 30 Laminate 11 Base Material 12 First Thermal Conductive Layer 12p Protruding Portion 12b Thermal Conductive Material 14 Second Thermal Conductive Layer 14b Second Thermal Conductive Particles 14d Low Melting Point Metal 15 Opposing Base Material X Average Thickness of the Base Material Y Interface Height of the Protruding Portion L1 Length of the Base Material when Viewed in Cross-Section L2 Length of the First Thermal Conductive Layer when Viewed in Cross-Section

Claims

1. A base material, and a first heat conduction layer provided on the base material, wherein the first heat conduction layer has an overhanging portion that contacts at least a part of the side surface of the base material, and a laminate characterized in that an interface height Y of the overhanging portion with respect to the side surface of the base material is more than 0 and equal to or less than X / 2 when an average thickness of the base material is X.

2. The laminate according to claim 1, wherein an interface height Y of the overhanging portion with respect to the side surface of the base material is equal to or more than X / 10 and equal to or less than X / 3.

3. When a length of the base material in a cross-sectional view is L １ and a length of the first heat conduction layer is L ２ , the laminate according to claim 1 or 2, satisfying the following formula: L １ < L ２ .

4. The laminate according to claim 1 or 2, wherein the base material is a silicon base material.

5. The laminate according to claim 1 or 2, wherein the first heat conduction layer contains a curing component, a curing agent, and a heat conduction material.

6. The laminate according to claim 5, wherein the heat conduction material is at least one metal filler selected from silver particles, copper particles, silver-coated copper particles, and copper-coated silver particles.

7. The laminate according to claim 5, wherein a volume filling ratio of the heat conduction material is equal to or more than 30% by volume and equal to or less than 90% by volume.

8. The laminate according to claim 5, further comprising a second heat conduction layer provided on the first heat conduction layer and containing a second curing component, a second curing agent, a second heat conduction material, and a second low melting point metal.

9. The laminate according to claim 5, wherein the first heat conductive layer further contains a polymer having at least one structure selected from a phenoxy structure, a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, a polyamide structure, and a polycarbonate structure in the molecule.

10. A step of applying a first thermally conductive composition containing a curing component, a curing agent, and a thermally conductive material so as to have an overhanging portion in contact with at least a part of the side surface of the base material on the base material; A step of heating the first thermally conductive composition, and A method for producing a laminate, characterized in that when the average thickness of the base material is X, the interface height Y of the overhanging portion with respect to the side surface of the base material is greater than 0 and less than or equal to X / 2.

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