Laminate, heat dissipation member, method for manufacturing same, heat dissipation housing, and method for manufacturing same

Abstract

Provided is a laminate exhibiting good heat dissipation properties while achieving weight reduction. The laminate has at least one metal layer and at least one resin layer. The unit weight of the laminate is 2.0 kg / m2 or less, and the thermal diffusivity in a direction perpendicular to the lamination direction of the laminate is 10 × 10-6m2 / s or more.

Description

Laminate, heat dissipation member and method for manufacturing the same, heat dissipation housing and method for manufacturing the same

[0001] The present invention relates to a laminate, a heat dissipation member and a method for manufacturing the same, and a heat dissipation enclosure and a method for manufacturing the same.

[0002] In recent years, interest in global environmental issues has grown worldwide, and environmentally friendly vehicles equipped with secondary batteries, such as electric vehicles and hybrid vehicles, have become increasingly popular. Many of these vehicles use a system in which direct current (DC) generated by the onboard secondary battery is converted to alternating current (AC) via an inverter, and the necessary power is then supplied to an AC motor to generate driving force. These vehicles also employ an electronic control unit (ECU) for electronically controlling the engine drive, driver assistance systems, and the like.

[0003] However, as electronic devices such as inverters and ECUs become smaller and more highly integrated, the amount of heat generated increases, resulting in a problem of temperature rise. Temperature rise in electronic devices can cause malfunctions. Therefore, various measures must be taken to suppress temperature rise in electronic devices.

[0004] One possible means for achieving this is to use SUS, which has excellent heat dissipation properties, as the housing, as disclosed in Patent Document 1, for example.

[0005] Japanese Patent Application Laid-Open No. 2020-172694

[0006] Incidentally, attention has been focused on improving the fuel economy (driving distance per unit of power) from the viewpoint of extending the cruising distance of electric vehicles, etc. However, since the aforementioned SUS housing is relatively heavy, if electronic devices are housed in the housing, the fuel economy of the electric vehicle, etc. is likely to decrease.

[0007] Furthermore, from the viewpoint of reducing the weight of electric vehicles and the like, replacement of SUS housings with plastic housings is currently being considered. However, plastic housings have lower heat dissipation properties than SUS housings. Therefore, as the temperature of electronic devices increases, it is possible that the electronic devices may malfunction.

[0008] Therefore, an object of one embodiment of the present invention is to provide a laminate that is lightweight and has good heat dissipation properties.

[0009] As a result of intensive research, the present inventors have found that in order to reduce the weight and improve the heat dissipation of a three-dimensional molded product such as a housing, it is important to form a laminate having at least one metal layer and at least one resin layer, and to control the thermal diffusivity in a direction perpendicular to the stacking direction of the laminate within an appropriate range. The present invention was completed based on the above findings, and is exemplified below. [1] A laminate having at least one metal layer and at least one resin layer, wherein the unit weight of the laminate is 2.0 kg / m 2 and the thermal diffusivity of the laminate in the direction perpendicular to the lamination direction is 10×10 -6 m 2 [2] The thermal diffusivity of the resin layer in a direction perpendicular to the lamination direction is 0.05 × 10 / s or more. -6 ~0.70 x 10 -6 m 2 / s. [3] The laminate according to [1], wherein the resin layer contains a magnetic metal material. [4] The laminate according to any one of [1] to [3], wherein the metal layer contains at least one selected from copper, copper alloys, aluminum, and aluminum alloys. [5] A heat dissipation member having the laminate according to any one of [1] to [4]. [6] A method for manufacturing a heat dissipation member, comprising a step of manufacturing a heat dissipation member using the laminate according to any one of [1] to [4]. [7] A heat dissipation enclosure having the laminate according to any one of [1] to [4]. [8] A method for manufacturing a heat dissipation enclosure, comprising a step of manufacturing a heat dissipation enclosure using the laminate according to any one of [1] to [4].

[0010] In one embodiment of the present invention, it is possible to achieve a reduction in weight while providing good heat dissipation properties.

[0011] FIG. 1 is a schematic diagram of a heat dissipation evaluation device used to evaluate the heat dissipation of sheet-like test specimens in Examples 1 to 5, Comparative Example 1, and Reference Example 1. FIG. 2 is a schematic diagram of sheet-like test specimens before three-dimensional molding in Examples 1 to 5, Comparative Example 1, and Reference Example 1. FIG. 3 is a schematic diagram for explaining a method for producing three-dimensionally molded test specimens from the sheet-like test specimens in Examples 1 to 5 and Reference Example 1. FIG. 4 is a schematic diagram of a heat dissipation evaluation device used to evaluate the heat dissipation of three-dimensionally molded test specimens in Examples 1 to 5, Comparative Example 1, and Reference Example 1.

[0012] The present invention is not limited to the following embodiments, and various modifications and variations of the components can be made without departing from the spirit of the invention. Furthermore, various inventions can be created by appropriately combining the multiple components disclosed in the embodiments.

[0013] [1. Laminate] In one embodiment, the laminate according to the present invention includes at least one metal layer and at least one resin layer. In the laminate, at least one metal layer and one resin layer are alternately stacked, so that the laminate can be made lighter than a single metal layer having the same thickness as the laminate. The laminate can be used as a heat dissipation member.

[0014] (Unit Weight) In one embodiment, from the viewpoint of weight reduction, the unit weight of the laminate is 2.0 kg / m 2 The laminate contains a resin layer with a relatively low unit weight, which allows for weight reduction. The upper limit of the unit weight is preferably 1.5 kg / m 2 or less, more preferably 1.0 kg / m 2 The unit weight is typically 0.1 kg / m or less as a lower limit. 2 or more, more typically 0.2 kg / m 2 Next, the unit weight can be measured by measuring the weight of a sheet sample cut into a 10 cm square and dividing the weight by the area.

[0015] (Thermal Diffusivity) In one embodiment, from the viewpoint of ensuring good heat dissipation when formed into a three-dimensional molded article, the thermal diffusivity of the laminate in a direction perpendicular to the stacking direction is 10×10 -6 m 2The lower limit of the thermal diffusivity is preferably 15×10 -6 m 2 / s or more, more preferably 20 × 10 -6 m 2 In addition, taking into consideration that the heat dissipation property tends to saturate when the thermal diffusivity exceeds a certain value, the upper limit is typically 140×10 -6 m 2 / s or less. In the present invention, thermal diffusivity is an index calculated by dividing thermal conductivity by specific heat and density, and indicates the speed at which a temperature gradient within a material is alleviated. In other words, even if the thermal conductivity is high, if the specific heat or density of a material is high, the temperature change will be small even when a certain amount of heat is applied. In particular, when different materials are combined, as in the present laminate, heat dissipation cannot be evaluated using thermal conductivity alone. However, by evaluating the thermal diffusivity in a direction perpendicular to the stacking direction of the entire laminate, it is possible to evaluate the heat dissipation ability of dispersing hot spots. The inventors have found that the relationship between the thermal diffusivity in a direction perpendicular to the stacking direction of a laminate and heat dissipation tends to be correlated in three-dimensional molded products, although there is no correlation in sheet-shaped samples. The inventors speculate that this is because the temperature change in sheet-shaped samples is dominated by thermal conduction within the sheet, while in three-dimensional molded products, the influence of thermal diffusivity is greater due to the influence of heat transfer between the heat source and the air near the heat source in addition to thermal conduction.

[0016] Next, the thermal diffusivity is measured as follows. The laminate is used as a sample, and a thermophysical property measuring device, Thermowave Analyzer TA35 Ultimate (manufactured by Bethel Corporation) or an equivalent device is used as the temperature measuring device. Next, a periodic heat source P0e iωt The surface of the sample on which the thermal diffusivity κ is to be measured is spot heated at room temperature (normal temperature) + 10°C. The AC component of the temperature at the heating point is T ac = T0e iωt Periodic heating source P0e iωt The temperature propagation induced by the surroundings can be expressed by the following number I. Note that the symbols in the following numbers I to V have the following meanings: κ: thermal diffusivity [m 2 / s] f: heating frequency [Hz] a: distance from heat source - gradient of phase graph [rad. / m] θ: phase [rad.] r: distance from heat source [m] μ: thermal diffusion length [m] ω: angular frequency [rad. / s] T: temperature [K] i: imaginary number t: time [s] k: wave number of temperature wave [1 / m] π: circumference constant P: laser power ρ: density c: specific heat

[0017]

[0018] The wave number k of the temperature wave in the above formula I is expressed by the following formula II.

[0019]

[0020] Therefore, the phase θ in the above equation I is expressed by the following equation III.

[0021]

[0022] Based on the above equation III, the results of measurements taken in the direction perpendicular to the thickness direction (stacking direction) of the sample are analyzed. Next, let r in the above equation III be the distance l from the heating point, and plot the distance l on the horizontal axis and the phase θ on the vertical axis. Here, the slope a of the resulting graph is given by the following equation IV.

[0023]

[0024] Therefore, the thermal diffusivity κ is expressed as the following number V.

[0025]

[0026] (Layer structure) Examples of the layer structure of the laminate include the following. (1) When the laminate has two layers, for example, a metal layer / resin layer can be mentioned. (2) When the laminate has three layers, for example, a metal layer / resin layer / metal layer, a resin layer / metal layer / resin layer, a resin layer / metal layer / metal layer, and a metal layer / resin layer / resin layer can be mentioned. (3) When the laminate has four layers, for example, a metal layer / metal layer / metal layer / resin layer, a metal layer / metal layer / resin layer / metal layer, a metal layer / metal layer / resin layer / metal layer, a metal layer / metal layer / resin layer / metal layer, a metal layer / metal layer / resin layer / resin layer, a metal layer / resin layer / metal layer / resin layer, and a metal layer / resin layer / resin layer / metal layer. (4) When the laminate has a five-layer structure, for example, metal layer / resin layer / metal layer / resin layer / metal layer, resin layer / metal layer / resin layer / metal layer / resin layer, metal layer / metal layer / metal layer / metal layer / resin layer, metal layer / metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / metal layer / resin layer / resin layer, metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / resin layer / metal layer, metal layer / resin layer / metal layer, metal layer / resin layer / metal layer Examples include metal layer / metal layer / resin layer, metal layer / resin layer / metal layer / resin layer / metal layer, metal layer / resin layer / metal layer / resin layer / resin layer, metal layer / resin layer / metal layer / resin layer / resin layer, metal layer / resin layer / resin layer / metal layer / resin layer, metal layer / resin layer / resin layer / resin layer / metal layer, metal layer / resin layer / resin layer / resin layer / resin layer, resin layer / metal layer / metal layer / resin layer / resin layer, resin layer / metal layer / metal layer / resin layer / resin layer, resin layer / metal layer / resin layer / resin layer, resin layer / resin layer / metal layer / resin layer, resin layer / resin layer / metal layer / resin layer, and resin layer / resin layer / resin layer / metal layer / resin layer.(5) When the laminate has six layers, for example, metal layer / resin layer / metal layer / resin layer / metal layer / resin layer, metal layer / metal layer / metal layer / metal layer / metal layer / resin layer, metal layer / metal layer / metal layer / metal layer / metal layer / resin layer, metal layer / metal layer / metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / metal layer / metal layer / resin layer / resin layer, metal layer / metal layer / metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / metal layer / resin layer / metal layer, metal layer / metal layer / metal layer / resin layer / resin layer / metal layer, metal layer / metal layer / metal layer / resin layer / resin layer / resin layer, metal layer / metal layer / resin layer / metal layer / metal layer / resin layer, metal layer / metal layer / resin layer / metal layer / resin layer / metal layer, metal layer / metal layer / resin layer / metal layer / resin layer / resin layer, metal layer / metal layer / resin layer / resin layer / metal layer / metal layer, metal layer / metal layer / resin layer / resin layer / metal layer / resin layer, metal layer / metal layer / resin layer / Resin layer / resin layer / metal layer, metal layer / metal layer / resin layer / resin layer / resin layer / resin layer, metal layer / resin layer / metal layer / metal layer / metal layer / resin layer, metal layer / resin layer / metal layer / metal layer / resin layer / metal layer, metal layer / Resin layer / metal layer / resin layer / resin layer / metal layer, metal layer / resin layer / resin layer / resin layer / resin layer / metal layer, resin layer / metal layer / metal layer / metal layer / metal layer / resin layer, resin layer / metal layer / metal layer / metal layer / resin layer / tree (6) When the laminate has a seven-layer structure, examples thereof include a resin layer / metal layer / resin layer / resin layer / metal layer / resin layer / resin layer, a resin layer / metal layer / resin layer / metal layer / resin layer / resin layer, a resin layer / metal layer / resin layer / metal layer / resin layer / resin layer, a resin layer / metal layer / resin layer / metal layer / resin layer / resin layer, a resin layer / metal layer / resin layer / resin layer / resin layer, a resin layer / metal layer / resin layer / resin layer / metal layer / resin layer, a resin layer / metal layer / resin layer / resin layer / metal layer / resin layer, a resin layer / metal layer / resin layer / resin layer / resin layer, a resin layer / metal layer / resin layer / resin layer / resin layer, a resin layer / metal layer / resin layer / resin layer / metal layer, a resin layer / resin layer / metal layer / resin layer / resin layer, and the like.

[0027] (Total Thickness) From the viewpoint of formability, the thickness of the laminate is preferably 70 μm or more, more preferably 100 μm or more, and even more preferably 200 μm or more. However, from the viewpoint of lightness and drilling processability, the thickness of the laminate is preferably 2000 μm or less, more preferably 1000 μm or less, and even more preferably 700 μm or less. The thickness of the laminate can be measured using a constant pressure thickness tester (THICKNESS METER B-1, manufactured by Toyo Seiki Seisakusho Co., Ltd.) in accordance with Method A of JIS K 6250:2019, by averaging the measured values ​​at four points within the surface of the sheet sample. The measurement can be performed with an indenter diameter of 5 mm and a pressure of 0.196 N on the indenter.

[0028] The ratio (M / R) of the total thickness (M) of the metal layers to the total thickness (R) of the resin layers can be set as appropriate, but from the viewpoint of formability, it is, for example, 0.05 to 0.40.

[0029] (Lamination Method) The lamination method of the resin layer and the metal layer may be performed by using an adhesive between the resin layer and the metal layer, or by thermocompression bonding of the resin layer to the metal layer without using an adhesive. A simple overlapping method without using an adhesive may be used, but considering the integrity of the laminate, it is preferable to join at least the edges (for example, each side if the laminate is rectangular) with tape, adhesive, or by thermocompression bonding. The adhesive is not particularly limited, but examples include acrylic resins, epoxy resins, urethanes, polyesters, silicone resins, vinyl acetates, styrene-butadiene rubbers, nitrile rubbers, phenolic resins, and cyanoacrylates. Urethanes, polyesters, and vinyl acetates are preferred for ease of production and cost reasons.

[0030] <Metal Layer> The material of the metal layer is not particularly limited, but it is preferable that the metal layer contains at least one selected from, for example, copper, copper alloy, aluminum, and aluminum alloy. From the viewpoint of electromagnetic wave shielding properties, it is preferable that the metal layer contains at least one material having a conductivity of 1.0×10 6 Materials with a r / m or higher are desirable. These are preferable from a practical standpoint.

[0031] (Thickness) The lower limit of the thickness per layer is, for example, 4 μm or more, and for example, 10 μm or more. On the other hand, the upper limit of the thickness per layer is, for example, 70 μm or less, and for example, 50 μm or less. The thickness of the metal layer can be measured in the same manner as the thickness of the laminate. If the thickness of the metal layer in the laminate is to be measured, it can be measured by observing the thickness cross section with an SEM or the like.

[0032] In one embodiment, when multiple metal layers are formed, all the metal layers may be made of the same material, or different materials may be used for each layer, and all the metal layers may have the same thickness, or different thicknesses may be used for each layer.

[0033] In one embodiment, the total thickness of the metal layers is, for example, 4 to 420 μm. The lower limit of the total thickness is, for example, 10 μm or more, and, for example, 30 μm or more. On the other hand, the upper limit of the total thickness is, for example, 110 μm or less, and, for example, 70 μm or less.

[0034] The shape of the metal layer is not particularly limited, but examples include metal foil. When copper foil is used as the metal foil, a high copper purity is preferred because it improves shielding properties, with the purity preferably being 99.5% by mass or higher, more preferably 99.8% by mass or higher. As the copper foil, rolled copper foil, electrolytic copper foil, metallized copper foil, etc. can be used, but rolled copper foil, which has excellent formability, is preferred. When alloying elements are added to copper foil to form a copper alloy foil, the total content of these elements and unavoidable impurities should be less than 0.5% by mass. In particular, it is preferable for the copper foil to contain a total of 50 to 2000 ppm by mass of at least one element selected from tin, manganese, chromium, zinc, zirconium, magnesium, nickel, silicon, and silver, and / or 10 to 50 ppm by mass of phosphorus, because this improves elongation compared to pure copper foil of the same thickness.

[0035] (Treated Film) From the viewpoint of improving heat dissipation, the treated film is formed on at least one surface of the metal layer. For example, the treated film may further include one or more selected from an electromagnetic wave absorption auxiliary film, a heat-resistant film, a rust-proof film, and a weather-resistant film made of an alloy containing copper. Examples of heat-resistant treated heat-resistant films include plating films and vapor-deposited films containing cobalt or nickel. Examples of rust-proof treated anti-corrosion films include inorganic plating films such as zinc or chromium, vapor-deposited films, and organic films such as benzotriazole. Examples of silane-coupling treated weather-resistant films include organic coating films containing silane coupling agents. That is, in addition to copper, cobalt, and nickel, the treated film may further contain one or more elements selected from zinc, molybdenum, tin, phosphorus, tungsten, chromium, and silicon. The treated film interposed between the metal layer and the resin layer can also improve the adhesion between the metal layer and the resin layer. The treated film can also improve shielding properties.

[0036] The electromagnetic wave absorbing auxiliary film can be produced by known methods, such as plating, metal vapor deposition, and sputtering. Among these, a method of forming an electromagnetic wave absorbing auxiliary film made of copper, cobalt, and nickel by plating the surface of a metal layer will be described below as an example. In the plating process for forming the electromagnetic wave absorbing auxiliary film, a particle film made of copper, cobalt, and nickel is formed on at least one surface of the metal layer.

[0037] (Plating Conditions (Roughening Plating): Copper, Cobalt, and Nickel Alloy Plating) An example of plating conditions for copper, cobalt, and nickel is as follows. Solution composition: copper 10 to 20 g / L, cobalt 5 to 15 g / L, nickel 5 to 15 g / L pH: 2 to 3 Solution temperature: 30 to 50°C Current density: 10 to 60 A / dm 2 Coulomb amount: 10 to 48 As / dm 2

[0038] In this case, the roughening plating treatment can be carried out in multiple stages under the above plating treatment conditions.

[0039] In the heat-resistant treatment, at least one of the following heat-resistant films 1 and 2 can be further formed on the aforementioned electromagnetic wave absorbing auxiliary film. The plating and vapor deposition conditions are shown below.

[0040] (Plating conditions for heat-resistant film 1) (Co-Ni plating: cobalt-nickel alloy plating) Solution composition: nickel 5 to 20 g / L, cobalt 1 to 8 g / L pH: 2 to 3 Solution temperature: 40 to 60°C Current density: 10 to 30 A / dm 2 Coulomb amount: 2 to 20 As / dm 2

[0041] (Plating conditions for heat-resistant film 2) (Ni-Zn plating: nickel-zinc alloy plating) Solution composition: nickel 2 to 30 g / L, zinc 2 to 30 g / L pH: 3 to 4 Solution temperature: 30 to 50°C Current density: 1 to 10 A / dm 2 Coulomb amount: 0.5 to 2 As / dm 2

[0042] In the rust prevention treatment, the following rust prevention film and / or weather-resistant film can be further formed on the aforementioned electromagnetic wave absorbing auxiliary film or heat-resistant film. The respective conditions are shown below.

[0043] (Plating conditions for anti-rust film) Solution composition: potassium dichromate 1 to 10 g / L, zinc 0.2 to 0.5 g / L pH: 3 to 4 Solution temperature: 50 to 70°C Current density: 0 to 2 A / dm 2 (0 A / dm 2 is for immersion chromate treatment.) Coulomb amount: 0 to 2 As / dm 2 (0 As / dm 2 is for immersion chromate treatment.)

[0044] (Types of Weather-Resistant Films (Silane Coupling Films)) Examples include the application of an aqueous solution of diaminosilane or epoxysilane. When a metal film such as a heat-resistant film or a plating film is formed by vapor deposition (dry plating) such as sputtering, or when a metal film such as a heat-resistant film or a plating film is formed by plating (wet plating) and the metal film such as a heat-resistant film or a plating film is normal plating (smooth plating, i.e., plating performed at a current density less than the limiting current density), the metal film or plating film does not affect the surface shape of the copper foil. The limiting current density varies depending on the metal concentration, pH, solution supply rate, electrode distance, and plating solution temperature. In this invention, however, the limiting current density is defined as the current density at the boundary between normal plating (where the plated metal is deposited in a film) and roughened plating (where the plated metal is deposited in a crystalline form (spherical, needle-like, frost-like, etc.), with unevenness). The limiting current density is the current density (visually determined) at the limit at which normal plating is achieved in a Hull cell test (just before burnt plating occurs). Specifically, the metal concentration, pH, and plating solution temperature are set to the plating production conditions, and a Hull cell test is performed. The state of metal layer formation (whether the plated metal is deposited in a layer or in a crystalline form) at the plating solution composition and plating solution temperature is then investigated. The current density at the boundary between normal plating and roughened plating is then determined based on a current density chart produced by Yamamoto Plating Tester Co., Ltd. The current density at the boundary is then defined as the limiting current density. This allows the critical current density to be determined for the plating solution composition and plating solution temperature. Generally, the shorter the electrode distance, the higher the critical current density tends to be. The Hull Cell test method is described, for example, in "Plating Practice Reader" by Kiyoshi Maruyama, published by Nikkan Kogyo Shimbun on June 30, 1983, pages 157 to 160. In order to perform plating below the critical current density, the current density during plating is set to 20 A / dm 2 It is preferable that the current is 10 A / dm or less. 2 More preferably, it is 8 A / dm or less. 2It is more preferable that the thickness of the anti-rust film and the weather-resistant film is extremely thin, and therefore the surface shape of the copper foil is not affected.

[0045] <Resin Layer> From the viewpoint of controlling the thermal diffusivity in the direction perpendicular to the stacking direction in the laminate, the resin layer is preferably a resin having a thermal diffusivity of, for example, 0.05×10 -6 m 2 / s ~ 0.70 × 10 -6 m 2 It is preferable to use a resin with a thermal diffusivity of 0.68×10 / s as the upper limit. -6 m 2 The lower limit of the thermal diffusivity is, for example, 0.05×10 -6 m 2 / s or more, for example, 0.07 × 10 -6 m 2 The thermal diffusivity can be measured by the method described above.

[0046] The resin layer may further contain a magnetic metal material. For example, a composite sheet may be used in which the magnetic metal material and a resin are mixed, dispersed, and integrally molded. Resins contained in the composite sheet include natural resins and synthetic resins, with synthetic resins being preferred from the viewpoint of processability. Fiber reinforcement materials such as carbon fiber, glass fiber, and aramid fiber may also be mixed into these materials. Synthetic resins having the aforementioned thermal diffusivity may be used as appropriate.

[0047] The composite sheet can be laminated to a resin layer or a metal layer in the form of a film or fiber. The composite sheet can be obtained by applying a mixed composition of an uncured magnetic metal material and a resin to a resin substrate having a release layer, curing the mixture, and then peeling it off from the resin substrate. For example, the composite sheet can also be formed by applying a mixed composition of an uncured magnetic metal material and a resin to the surface of a resin layer, the surface of a metal layer, or the aforementioned treatment film, and then curing the mixture. For ease of manufacture, it is preferable to form a composite sheet that can be attached to the surface of a resin layer, the surface of a metal layer, or the treatment film described below. The volume ratio of resin to magnetic metal material in the composite sheet is, for example, 75:25 to 1:99. The volume ratio of the resin to the magnetic metal material can be calculated, for example, by SEM observation to calculate the area ratio of the magnetic metal material on the surface perpendicular to the thickness direction of the composite sheet, and then by SEM observation to calculate the thickness ratio of the magnetic metal material relative to the thickness of the composite sheet. The volume ratio of the magnetic metal material in the composite sheet is calculated from the product of these values, and the volume ratio can be calculated by: resin:magnetic metal material = (100 - volume ratio of magnetic metal material): volume ratio of magnetic metal material. Furthermore, the composite sheet may further contain conductive particles or conductive fibers other than the magnetic metal material, as long as they do not impair the scope of the present invention. Note that known metal species for the conductive particles or conductive fibers can be used as long as they have good conductivity, but examples include copper, copper alloys, aluminum, aluminum alloys, and carbon. In this case, the mass ratio of the resin to the conductive particles or conductive fibers is, for example, 70:30 to 1:99.

[0048] The magnetic metal material preferably contains at least one material selected from nickel, iron, permalloy (Ni-Fe alloy), silicon iron, permendur, sendust (Fe-Si-Al alloy), soft ferrite, Fe-based amorphous, Co-based amorphous, and nanocrystal. It is presumed that the higher the filling rate of these materials when combined, the better the heat dissipation properties of the laminate formed by laminating them with a metal layer.

[0049] (Thickness) The lower limit of the thickness per layer is, for example, 5 μm or more, and for example, 10 μm or more. On the other hand, the upper limit of the thickness per layer is, for example, 300 μm or less, and for example, 200 μm or less. The thickness of the resin layer can be measured in the same manner as the thickness of the laminate. If the thickness of the resin layer in the laminate is to be measured, it can be measured by observing the thickness cross section with an SEM or the like.

[0050] In one embodiment, when a plurality of resin layers are formed, all the resin layers may be made of the same material, or different materials may be used for each layer.Furthermore, all the resin layers may have the same thickness, or different thicknesses may be used for each layer.

[0051] In one embodiment, the total thickness of the resin layer is, for example, 10 to 1200 μm. The lower limit of the total thickness is, for example, 10 μm or more, and, for example, 20 μm or more. On the other hand, the upper limit of the total thickness is, for example, 1200 μm or less, and, for example, 1000 μm or less.

[0052] [2. Heat Dissipation Member] In one embodiment, the heat dissipation member according to the present invention has the laminate described above. The heat dissipation member according to the present invention can also be used for electromagnetic wave shielding.

[0053] In one embodiment, the method for manufacturing the heat dissipation member includes a step of manufacturing the heat dissipation member using the laminate described above. The manufacturing method can manufacture the heat dissipation member by known processing means.

[0054] [3. Heat Dissipating Housing] In one embodiment, the heat dissipating housing according to the present invention includes the laminate described above. The heat dissipating housing may further include a housing main body capable of housing an electronic device such as an inverter or an ECU. For example, the housing main body may be made of resin, with the laminate as its inner surface. In this case, the heat dissipating housing can be insert-molded with the laminate as an insert part. With these configurations, heat generated from an electronic device housed in the heat dissipating housing is transferred to the laminate and dissipated to the outside via the laminate. As a result, temperature rise in the electronic device is suppressed, preventing malfunction of the electronic device. Furthermore, the housing main body of the heat dissipating housing may be a laminate. The heat dissipating housing of the present invention can also be used for electromagnetic wave shielding.

[0055] In one embodiment, the method for manufacturing the heat dissipating housing includes a step of manufacturing the heat dissipating housing using the laminate described above. The manufacturing method can manufacture the heat dissipating housing by known processing means.

[0056] The present invention will be specifically described based on Examples, Comparative Examples, and Reference Examples. The following Examples, Comparative Examples, and Reference Examples are merely specific examples intended to facilitate understanding of the technical content of the present invention, and the technical scope of the present invention is not limited by these specific examples.

[0057] [Preparation of Laminate] In Examples 1 to 5, metal layers 1 and 2 and resin layer 1 were prepared as materials in the order of construction shown in Table 1. Metal layer 2 was annealed at a material temperature of 200°C for a heating retention time of 1 hour, and metal layer 1 was annealed at a material temperature of 200°C for a heating retention time of 1 hour after providing each treatment film, as described below. Metal layers 1 to 3 in Table 1 are as follows. A commercially available resin film (nominal thickness 100 μm) was used as resin layer 1. Metal layer 1: Copper foil (nominal thickness 18 μm, tough pitch copper (JIS H 3100 (C1100): 2018 standard), manufactured by JX Nippon Mining & Metals Corporation) Metal layer 2: Aluminum foil (nominal thickness 35 μm, A1050 (JIS H 4000: 2017 standard), commercially available) Metal layer 3: SUS 304 steel plate (nominal thickness 300 μm, TS300-300-03, manufactured by Iwata Corporation)

[0058] Next, in Examples 1 to 4, the following treatment films were formed in this order on the surface of the metal layer 1 facing the resin layer: (A) electromagnetic wave absorbing auxiliary film, (B) heat-resistant film, (C) heat-resistant film, (D) rust-proof film, and (E) weather-resistant film. The treatment films were formed in order to bond the resin layer 1 to the surface of the metal layer 1. The thickness of the treatment films was submicron (10 -1 The formation time was adjusted appropriately so that the thickness of the metal layer 1 was about 1 μm or less. The surface of the metal layer 1 that came into contact with air (the outermost surface) was treated with a heat-resistant film (C) and a rust-preventive film (D). After the formation of each treatment film, the metal layer 1 was annealed at a material temperature of 200° C. for a heating time of 1 hour.

[0059] (A) Electromagnetic wave absorption auxiliary film (Cu-Co-Ni alloy plating (roughening plating)) Solution composition: copper 15.5 g / L, cobalt 7.0 g / L, nickel 9.3 g / L pH: 2.3 Solution temperature: 36.0°C Current density: (upper surface) 1st time: 21.3 A / dm 2 , 2nd time: 29.9A / dm 2 , 3rd time: 56.8 A / dm 2 (Bottom surface) 1st time: 14.9A / dm 2 , 2nd time: 26.1 A / dm 2 , 3rd time: 56.8 A / dm2 Coulomb amount: (Top surface) 1st time: 15.3 As / dm 2 , 2nd time: 21.5 As / dm 2 , 3rd time: 20.5 As / dm 2 (Bottom surface) 1st time: 10.7As / dm 2 , 2nd time: 18.8 As / dm 2 , 3rd time: 27.4 As / dm 2 (B) Heat-resistant film (Co—Ni alloy plating treatment) Solution composition: nickel 12.5 g / L, cobalt 3.1 g / L pH: 2.0 Solution temperature: 50°C Current density: (upper surface) 17.5 A / dm 2 , (bottom surface) 19.3A / dm 2 Coulomb amount: (top surface) 6.3 As / dm 2 , (bottom surface) 6.9As / dm 2 (C) Heat-resistant film (Ni-Zn alloy plating treatment) Solution composition: Nickel 23.5 g / L, zinc 4.5 g / L pH: 3.7 Solution temperature: 40°C Current density: (upper surface) 3.6 A / dm 2 , (bottom surface) 4.0A / dm 2 Coulomb amount: (upper surface) 1.5 As / dm 2 , (bottom surface) 1.6As / dm 2 (D) Anti-rust film (immersion chromate treatment) Liquid composition: potassium dichromate 3.0 g / L, zinc 0.33 g / L pH: 3.65 Liquid temperature: 55°C Treatment time: 5 seconds (E) Weather-resistant film (silane coupling treatment) Silane coupling agent: N-(2-aminoethyl)-3-aminopropyltrimethoxysilane Silane coupling agent concentration: 1.2 vol% Treatment temperature: 20°C (room temperature) Treatment time: 5 seconds

[0060] Next, in Examples 1 to 5, in order to produce a laminate by laminating a metal layer and a resin layer, an adhesive layer was formed between the metal layer and the resin layer via an adhesive (RU80 / H-5 (urethane adhesive for dry lamination, manufactured by Rock Paint Co., Ltd.)). The thickness of these adhesive layers was approximately 5 μm. As a result, a sheet-like laminate was produced in Examples 1 to 5. In Comparative Example 1, a SUS304 steel plate was used. In Reference Example 1, a sheet of resin layer 1 was used.

[0061] [Characteristics Evaluation] (Unit Weight) According to the method described above, the unit weight of each of Examples 1 to 5, Comparative Example 1 and Reference Example 1 was measured. The results are shown in Table 1.

[0062] (Thermal Diffusivity) The thermal diffusivities of Examples 1 to 5, Comparative Example 1, and Reference Example 1 were measured using a thermophysical property measuring device, Thermowave Analyzer TA35 Ultimate, according to the method described above. For the thermal diffusivity in the direction perpendicular to the stacking direction of the laminate (meaning the thickness direction in Comparative Example 1 and Reference Example 1) except for Example 3, the thermal diffusivity was measured at five points near the center on the surface of each test specimen, and the arithmetic mean value is shown in Table 1. For Example 3, the thermal diffusivity in the direction perpendicular to the stacking direction of the laminate was measured at one point near the center on the surface of the test specimen, and the results are shown in Table 1.

[0063] (Evaluation of Heat Dissipation of Sheet-Like Test Pieces) The heat dissipation of Examples 1 to 5, Comparative Example 1, and Reference Example 1 was evaluated using the following procedures (1) to (5). (1) Examples 1 to 5, Comparative Example 1, and Reference Example 1 were cut with scissors to obtain 5 cm x 5 cm test pieces. The surface of the test piece was coated with blackbody spray (TA410KS, manufactured by TASCO, emissivity 0.94) to ensure a constant emissivity. (2) In the heat dissipation evaluation device 100 shown in FIG. 1, a sheet-like test piece 110, a heat dissipation resin (thickness 1000 μm, TMS-E14N, manufactured by Takeuchi Industries Co., Ltd.) 120, a heating unit 130, and a low-dielectric resin (thickness 400 μm, GHPL-830NX type A, manufactured by Mitsubishi Gas Chemical Company, Inc.) 140 were arranged in this order from top to bottom. At this time, a heater (WALN-5, manufactured by Sakaguchi Electric Heating Co., Ltd.) 132 and a thermocouple 134 were connected to the heating section 130. Current to the heater 132 was supplied from a constant-voltage power supply (model PMX18-2A, manufactured by KIKUSUI). Signal control to the power supply was performed using Wavy for PMX Free software, and current application and termination were performed by creating a sequence in the software. Temperature measurements from the thermocouple 134 were constantly recorded during the test on a data logger (model LR8431, manufactured by HIOKI). A thermal camera 150 (model C51.1, manufactured by FLIR) was installed 30 cm above the sheet-like test specimen 110. (3) A heat-dissipating resin 120 of the same area was placed on the heating section 130, and Examples 1 to 5, Comparative Example 1, and Reference Example 1 were then closely attached to it. A fixed voltage of 10 V was then applied to the heater 132 for 20 seconds. After 20 seconds, the application was stopped. (4) After 2 minutes had passed since the start of application, the temperature of the sheet-like specimen 110 was quickly measured using a thermal camera 150 placed above the sheet-like specimen 110. Table 1 shows the maximum temperature of the sheet-like specimen 110. When the maximum temperature of the heating section 130 was quickly measured using a thermocouple 134 immediately after application was stopped without a specimen placed on it, it was 65°C.

[0064] (Evaluation of Heat Dissipation of Three-Dimensional Molded Test Pieces) The heat dissipation of Examples 1 to 5, Comparative Example 1, and Reference Example 1 was evaluated using the following procedures (1) to (8). Note that, in the following procedures (2) to (4), test pieces were produced by drawing at room temperature (approximately 22 to 26°C). (1) Examples 1 to 5, Comparative Example 1, and Reference Example 1 were cut with scissors to obtain polygonal test pieces 210 as shown in FIG. 2. The length L of the diagonal line between vertex A of polygonal test piece 210 and vertex B opposite vertex A was set to 72 mm. (2) The outer periphery of polygonal test piece 210 was clamped between die 220 and holder 230 of processing machine 200 shown in FIG. 3(A). (3) As shown in FIG. 3(B), punch 240 (tip surface size: 30 mm x 40 mm) was moved vertically downward 15 mm along die 220 and holder 230 and pressed into the die hole. The clearance between the die 220 and the punch 240 was set to 0.6 mm. (4) As shown in FIG. 3(C), the punch 240 was moved vertically upward and returned to its original position. This resulted in a drawn three-dimensional molded specimen 215. This three-dimensional molded specimen 215 had a bottomed shape. Since the bottom of Comparative Example 1 was damaged by the drawing process, it was bent and processed to have a tip surface measuring 30 mm x 40 mm and a height of 15 mm. The convex outer surface of the specimen was coated with a blackbody spray (TA410KS, manufactured by TASCO, emissivity 0.94) to maintain a constant emissivity. (5) In the heat dissipation evaluation device 300 shown in FIG. 4, in order to sandwich the outer periphery of the three-dimensional molded test piece 215, a heat dissipation resin (thickness 1000 μm, TMS-E14N, manufactured by Takeuchi Kogyo Co., Ltd.) 320, the outer periphery of the three-dimensional molded test piece 215, copper foil (thickness 18 μm, TPC, manufactured by JX Metals Corporation) 360, low dielectric resin (thickness 400 μm, GHPL-830NX type A, manufactured by Mitsubishi Gas Chemical Company, Inc.) 340, copper foil (thickness 18 μm, TPC, manufactured by JX Metals Corporation) 365 were arranged in order from top to bottom. Note that when viewed from above, the heating unit 330 was placed on the low dielectric resin 340 so that the center of gravity of the three-dimensional molded test piece 215 and the center of gravity of the heating unit 330 overlap. At this time, a heater 332 and a thermocouple 334 were connected to the heating unit 330.Current to the heater was supplied from a constant-voltage power supply (model PMX18-2A, manufactured by KIKUSUI). Signal control to the power supply was performed using Wavy for PMX Free software, and current application and termination were performed by creating and executing sequence control in the software. Temperature measurements from the thermocouple 334 were continuously recorded during the test on a data logger (model LR8431, manufactured by HIOKI). A thermal camera 350 (model C51.1, manufactured by FLIR) was installed 30 cm above the three-dimensional molded specimen 215. (6) A fixed voltage of 10 V was applied to the heater 332 for 70 seconds. After 70 seconds, the application was stopped. (7) After the application was stopped, the temperature of the heating section 330 was immediately measured using the thermocouple 334. As a result, the temperature was 370°C in all of Examples 1 to 5, Comparative Example 1, and Reference Example 1. (8) Furthermore, after 2 minutes had elapsed since the start of application of the voltage, the temperature of the three-dimensional molding test piece 215 was quickly measured using a thermal camera 350 placed above the three-dimensional molding test piece 215. Table 1 shows the maximum temperature of the three-dimensional molding test piece 215.

[0065] (Heat dissipation evaluation) In the heat dissipation evaluation of the sheet-like test specimen and the three-dimensional molded test specimen, the test specimens were measured two minutes after the start of application of voltage, and the maximum temperatures of both test specimens were evaluated as "◎" if they were 40°C or less, "◯" if they were greater than 40°C and 45°C or less, and "△" if they were otherwise, as shown in Table 1. In addition, "◎" or "◯" indicated that the heat dissipation was good, while "△" indicated that the heat dissipation was not good.

[0066] (Shielding Properties) The shielding properties of Examples 1 to 5, Comparative Example 1, and Reference Example 1 in sheet form were measured. First, the outer periphery of each test specimen was fixed with tape to prevent misalignment during measurement. The magnetic field shielding properties of each material were evaluated at a frequency of 100 kHz by the KEC method under room temperature (approximately 22 to 26°C) conditions using a magnetic field measuring jig of a KEC method shielding effectiveness measuring device (manufactured by Techno Science Corporation, JSE-KEC), a network analyzer (manufactured by Keysight Technologies, E5080), and an amplifier (manufactured by Anritsu Corporation, MH648A). The results are shown in Table 1.

[0067]

[0068] (Discussion based on Examples) The laminates in Examples 1 to 5 were laminates having at least one metal layer and at least one resin layer, and the unit weight of the laminates was 2.0 kg / m 2 and the thermal diffusivity in the direction perpendicular to the stacking direction of the laminate is 10 × 10 -6 m 2 / s or more, the laminates in Examples 1 to 5 had good heat dissipation properties while achieving weight reduction. Furthermore, the laminates in Examples 1 to 5 had a shielding effect of 10 dB or more at 100 kHz, and also had good shielding characteristics. According to Table 1 above, Example 4 had slightly poorer heat dissipation properties than Example 3, which had a slightly poorer thermal diffusivity. The reason for this is presumably that the heat dissipation properties were saturated when the thermal diffusivity reached a certain value or more.

[0069] On the other hand, Comparative Example 1 was composed of only a metal layer, and therefore had a unit weight 2.4 times or more larger than that of the laminates in Examples 1 to 5.

[0070] 100, 300 Heat dissipation evaluation device 110 Sheet-shaped test piece 120, 320 Heat dissipation resin 130, 330 Heating unit 132, 332 Heater 134, 334 Thermocouple 140, 340 Low dielectric resin 150, 350 Thermocamera 200 Processing machine 210 Polygonal test piece 215 Three-dimensionally formed test piece 220 Die 230 Holder 240 Punch 360, 365 Copper foil A, B Vertex L Diagonal length

Claims

1. A laminate having at least one metal layer and at least one resin layer, The unit weight of the laminate is 2.0 kg / m 2 and the thermal diffusivity of the laminate in a direction perpendicular to the lamination direction is 10×10 -6 m 2 / s or more.

2. The thermal diffusivity in the direction perpendicular to the lamination direction of the resin layer is 0.05×10 -6 ~0.70 x 10 -6 m 2 The laminate according to claim 1, wherein:

3. The laminate according to claim 1 , wherein the resin layer contains a magnetic metal material.

4. The laminate according to claim 1 or 2, wherein the metal layer contains at least one selected from copper, a copper alloy, aluminum, and an aluminum alloy.

5. A heat dissipation member comprising the laminate according to claim 1 or 2.

6. A method for producing a heat dissipation member, comprising the step of producing a heat dissipation member by using the laminate according to claim 1 or 2.

7. A heat dissipation housing comprising the laminate according to claim 1 or 2.

8. A method for producing a heat dissipating housing, comprising the step of producing a heat dissipating housing using the laminate according to claim 1 or 2.