laminated body

Abstract

This invention proposes a laminate that improves heat dissipation compared to previous methods while ensuring practicality in terms of cost, size, and basic performance. In the laminate 1, the heat-conducting member 4 is made of copper and has a space 4a. A member with a higher thermal conductivity than copper is provided in the space 4a, or a working fluid that is heated and evaporates and dissipates heat and condenses is provided, along with a core that permeates the working fluid to generate capillary force, and satisfies the following formula (1). Wherein, V: apparent volume of the heat-conducting member 4 [mm 3], S: the proportion of the volume occupied by the space 4a relative to the apparent volume V [%], A: the proportion of the area of ​​the heat-conducting member 4 in close contact with the insulating layer 3 relative to the area of ​​the insulating layer 3 side of the heat-conducting member 4 [%], λ: thermal conductivity of the insulating layer 3 [W / mK], and t: thickness of the insulating layer 3 [mm].

Description

Technical Field

[0001] This invention relates to a laminate. Prior Technology

[0002] In recent years, there has been an increase in the use of high-brightness light-emitting diodes (LEDs) or electronic components that carry high currents, such as power modules. These electronic components generate heat at high temperatures when carrying high currents. Therefore, ensuring adequate heat dissipation is crucial when using such components.

[0003] Previously, as a component for dissipating heat from electronic components, a multilayer assembly is known that comprises a substrate, an insulating layer, and a circuit pattern, and on which electronic components can be mounted (see, for example, Patent Document 1). With this multilayer assembly, heat generated in the electronic components can be conducted from the circuit pattern through the insulating layer to the substrate, and then dissipated from the substrate to the air. [Existing Technical Documents] [Patent Literature]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2002-012653 Summary of the Invention

[0005] [The problem that the invention aims to solve] To improve the heat dissipation of such multilayer structures, for example, a heat sink including fins can be used as a substrate to increase the heat dissipation area.

[0006] Furthermore, as a method to improve heat dissipation without relying on the shape of the substrate, increasing the thermal conductivity of the insulating layer and the circuit pattern can be cited. Regarding the circuit pattern, materials with high thermal conductivity (e.g., copper) have been used previously. Additionally, it is known that the insulating layer uses a resin composition containing fillers with high thermal conductivity. However, even using these methods, there is a limit to the improvement in heat dissipation, making further improvement difficult. Moreover, if only heat dissipation is to be improved, the circuit pattern can simply be formed using a material with higher thermal conductivity than copper (e.g., silver), but this is not a practical method due to the significantly increased cost. Furthermore, for example, increasing the filler content in the resin composition can improve the thermal conductivity of the insulating layer, but thermal conductivity and insulation properties in the insulating layer are generally inversely related; therefore, insulation properties deteriorate with increasing thermal conductivity. This tendency is particularly pronounced in insulating layers using resin compositions.

[0007] Increasing the thickness of the circuit pattern can improve its heat dissipation, but the size of the multilayer also increases with the thickness, and there are also manufacturing problems (for example, when the circuit pattern is formed by etching a copper plate, the cycle time increases with the thickness).

[0008] In view of this, the object of the present invention is to provide a multilayer material that can improve heat dissipation compared to the prior art while ensuring practical cost or size, basic performance, etc. [Methods for solving problems]

[0009] The present invention is a laminate, which sequentially laminates a substrate, an insulating layer and a heat-conducting member, and is capable of conducting heat from a heating element from the heat-conducting member to the substrate via the insulating layer. In the laminate, the heat-conducting member is made of copper and has a space on its inner side. A member with a higher thermal conductivity than copper is provided in the space, or a working fluid that is heated and evaporates and dissipates heat and condenses is provided, and a core that allows the working fluid to permeate and generate capillary force is provided, and satisfies the following formula (1). 0.01 <V×(S^1.5)×A×λ×t×10^(-9) 75 ···(1) in, V: Apparent volume of the heat-conducting component [mm3] S: The percentage of the volume occupied by the space portion relative to the apparent volume of the heat-conducting component [%) A: The percentage of the area of ​​the heat-conducting member in close contact with the insulating layer at its boundary surface, relative to the area of ​​the insulating layer side of the heat-conducting member [%). λ: Thermal conductivity of the insulating layer [W / mK] t: The thickness of the insulating layer [mm].

[0010] The laminate is preferably one that satisfies the following equation (2). 0.02 t 0.4 ···(2)

[0011] The laminate is preferably one that satisfies the following equation (3). 80 A 100 ···(3) [The effects of the invention]

[0012] The laminate of the present invention can improve heat dissipation compared to the past while ensuring practical cost or size, basic performance, etc. Simple Explanation of the Diagram

[0013] Figure 1 is a diagram showing a laminate of one embodiment of the present invention. Implementation

[0014] Hereinafter, an embodiment of the laminate of the present invention will be described with reference to the accompanying drawings. Furthermore, the drawings shown are schematic, and the thickness or width of each part, the ratio of each part to the other, etc., may sometimes differ from those in the actual embodiment.

[0015] Figure 1 is a diagram showing the laminate 1 of this embodiment. The laminate 1 includes a substrate 2, an insulating layer 3, and a heat-conducting member 4. In the laminate 1 of this embodiment, an electronic component 5 is provided on the surface side of the heat-conducting member 4 (the side opposite to the side where the heat-conducting member 4 and the insulating layer 3 face each other). Furthermore, a heat-conducting grease (heat-dissipating grease) may also be applied to the boundary surface between the insulating layer 3 and the heat-conducting member 4.

[0016] The substrate 2 is formed of metals such as copper, aluminum, and iron (which can be elemental metals or alloys). The substrate 2 can be a single-layer structure or a multi-layer structure. In addition, it can be composed of a single component or composed of multiple components combined together. In this embodiment, the substrate 2 is plate-shaped, but it can also be a heat sink with comb-shaped fins.

[0017] The insulating layer 3 is formed of an insulating material and is disposed such that it covers the surface of the substrate 2. The insulating layer 3 may cover the entire surface of the substrate 2 or a portion of the surface.

[0018] The insulating layer 3 is formed of a resin composition containing a thermosetting resin. Examples of thermosetting resins include epoxy resin, phenolic resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, cyanate ester resin, etc. One thermosetting resin may be used alone, or two or more may be used in combination. The resin composition may also include, for example, curing agents (such as amine curing agents, imidazole curing agents, phenolic curing agents, etc.), curing accelerators (such as benzoxazine compounds, borate complexes, zinc naphthenate, cobalt naphthenate, tin octoate, cobalt octoate, cobalt diacetoacetone (II), cobalt triacetoacetone (III) and other organometallic salts, phenol, bisphenol A, nonylphenol and other phenolic compounds, tertiary amines, tertiary amine salts, phosphine, phosphonium salts, etc.), fillers (such as alumina, silicon dioxide, aluminum nitride, boron nitride, silicon nitride, magnesium oxide, etc.), and additives (such as stabilizers, ion scavengers, flexibility imparting agents, etc.).

[0019] The insulating layer 3 can also be constructed using a plate-shaped ceramic substrate, such as silicon nitride, aluminum nitride, or alumina. Since ceramic substrates have high thermal conductivity (for example, silicon nitride has a thermal conductivity of approximately 90 W / mK, aluminum nitride approximately 200 W / mK, and alumina approximately 30 W / mK), using a ceramic substrate for the insulating layer 3 offers the advantage of efficiently transferring heat to the base substrate 2. On the other hand, ceramic substrates are generally expensive and difficult to thin. As an example, the thickness of the insulating layer 3 using a ceramic substrate is generally 0.2 mm to 0.4 mm, which is thicker than that of the insulating layer 3 using the aforementioned resin composition. The optimal choice is selected considering these characteristics when constructing the insulating layer 3.

[0020] The heat-conducting member 4 is formed of copper, a relatively inexpensive material with high thermal conductivity. A space 4a is provided on the inner side of the heat-conducting member 4. In this embodiment, the heat-conducting member 4 is a rectangular parallelepiped in the example drawing, and the space 4a is also rectangular parallelepiped, but the shape can be adapted. When forming the heat-conducting member 4 including the space 4a on the inner side, for example, the following method can be used: prepare a plate-shaped member located on the surface side of the heat-conducting member 4 and other members that are cylindrical with a bottom, and fix these members together by welding or bonding.

[0021] In this embodiment, the space 4a is provided with a working fluid that is heated, evaporates, dissipates heat, and condenses, and a wick that permeates the working fluid to generate capillary force. By using this working fluid and wick, the heat-conducting member 4 can function as a heat-conducting chamber. That is, the working fluid evaporates due to heat from the electronic component 5 disposed on the surface of the heat-conducting member 4, and the evaporated working fluid moves within the space 4a, thereby allowing heat to diffuse towards the surface of the heat-conducting member 4. When the diffused vapor dissipates heat and condenses, it returns to the working fluid, and the working fluid permeating the wick returns to the vicinity of the electronic component 5 disposed on the surface of the heat-conducting member 4 by capillary force. By repeatedly performing this evaporation and condensation of the working fluid, heat from the electronic component 5 can be effectively diffused towards the surface of the heat-conducting member 4. Furthermore, the heat-conducting member 4 in this embodiment is configured such that even when force is applied to the surface or back side, the space 4a can be prevented from deforming inward due to crushing. As an example of this structure, the thickness of the surface or back of the heat-conducting member 4 can be set to a degree that prevents the space portion 4a from deforming inwards under pressure, or a reinforcing column can be provided in the space portion 4a to connect the surface and back of the heat-conducting member 4.

[0022] Alternatively, a component with a higher thermal conductivity than copper (in this embodiment, copper has a thermal conductivity of 390 W / mK) can be provided in the space portion 4a to replace the working fluid and the core. Examples of such components include silver (thermal conductivity of 427 W / mK) and diamond (thermal conductivity of approximately 1000 W / mK). Furthermore, this component can be formed from a single material or from a composite of two or more materials (for example, a graphite sheet (thermal conductivity of approximately 1800 W / mK) formed by laminating a thin graphite film between polyethylene terephthalate (PET) and other materials). With this thermally conductive component 4, by providing a component with a higher thermal conductivity than copper in the space portion 4a, the thermal conductivity can be improved compared to a component of the same shape formed solely of copper.

[0023] When the heat-conducting component 4 is conductive, it can also be configured such that the external device and the electronic component 5 are electrically connected relative to the heat-conducting component 4. In this case, the heat-conducting component 4 functions as part of the circuit connecting the external device and the electronic component 5.

[0024] In this embodiment, electronic component 5 is a high-brightness LED or a power semiconductor that carries a large current, and it becomes a heat source that generates heat at high temperatures when the current flows. Electronic component 5 in this embodiment has a metal portion on its lower surface, which is fixed to the heat-conducting member 4 by a bonding material (e.g., solder or a sintered material with silver as the main component). Furthermore, the metal portion can function as a heat sink to dissipate heat generated in electronic component 5 to the outside, or it can function as an electrode (e.g., a drain when electronic component 5 is a power semiconductor) for electrically connecting electronic component 5 to heat-conducting member 4. Although not shown in the figure, when an electrode (e.g., a gate or source when electronic component 5 is a power semiconductor) is provided on the upper surface of electronic component 5, the electrode is connected to a lead frame or the like, which serves as an electrical external terminal of an external device, by a bonding wire. Electronic component 5 is equivalent to a "heat-generating element" in this specification.

[0025] The study was conducted repeatedly using the multilayer 1 with this structure, and it was confirmed that, under the condition of satisfying the following formula (1), the cost and size of the multilayer 1 can be controlled within the practical range. In addition, the insulation and heat dissipation of the insulating layer 3 can be further improved compared with the previous multilayer (which uses a known insulating layer and the circuit pattern is formed only by copper).

[0026] Here, equation (1) is as follows. 0.01 <V×(S^1.5)×A×λ×t×10^(-9) 75 ···(1) in, V: Apparent volume of heat-conducting component 4 [mm³] S: The percentage of the volume occupied by the space portion 4a relative to the apparent volume of the heat-conducting component 4 [%) A: The percentage of the area of ​​the heat-conducting member 4 in close contact with the insulating layer 3 at the boundary surface relative to the area of ​​the insulating layer side (area of ​​the back side) of the heat-conducting member 4 [%) λ: Thermal conductivity of insulation layer 3 [W / mK] t: Thickness of insulation layer 3 [mm]

[0027] Furthermore, it was confirmed that the insulation of the insulating layer 3 can be stably ensured when the following equation (2) is satisfied, and the heat dissipation is also greatly improved.

[0028] Here, equation (2) is as follows. 0.02 t 0.4 ···(2)

[0029] Furthermore, it was confirmed that the improvement in heat dissipation is also excellent when the following equation (3) is satisfied.

[0030] Here, equation (3) is as follows. 80 A 100 ···(3)

[0031] The apparent volume V of the heat-conducting component 4 is calculated based on its shape (outline). The apparent volume V can be calculated by measuring the actual shape (outline) of the heat-conducting component 4 using a 3D shape measuring machine (either contact or non-contact type). Alternatively, the apparent volume V can also be calculated based on the dimensions of the heat-conducting component 4 during its design.

[0032] If the apparent volume V of the heat-conducting component 4 is too small, the heat from the electronic component 5 cannot be sufficiently conducted to the insulating layer 3. If the apparent volume V of the heat-conducting component 4 is too large, the cost of the laminate 1 will increase, and the size will also be too large. Taking these aspects into consideration, the apparent volume V is preferably 100 [mm 3] to 60000 [mm 3], more preferably 250 [mm 3] to 55000 [mm 3], and even more preferably 500 [mm 3] to 50000 [mm 3].

[0033] Regarding the proportion S of the volume occupied by the space portion 4a relative to the apparent volume of the heat-conducting member 4, the mass M1 of the apparent volume V of the heat-conducting member 4 can be calculated based on the apparent volume V and the specific gravity of copper, the material of the heat-conducting member 4. The actual mass M2 of the heat-conducting member 4 can be calculated using a precision balance, and then calculated according to the following formula. Here, the specific gravity of copper is 8.94 [g / cm 3]. M1 = V × 8.94 × 10^(-3) [g] S = (1 - (M1 / M2)) × 100 [%] Furthermore, the ratio S can also be calculated based on the external dimensions of the heat conduction component 4 and the dimensions of the space portion 4a during the design process.

[0034] The proportion S of the volume occupied by the space portion 4a relative to the apparent volume of the heat-conducting component 4 has a particularly large impact on the cost, size, insulation, and heat dissipation effects obtained by the laminate 1. In Equation (1), the degree of influence of this proportion S is reflected by using a power of S with an exponent of 1.5.

[0035] Furthermore, when the working fluid and the core are disposed in the space 4a, the ratio S is difficult to function as a heat-conducting plate, whether it is too small or too large. Considering this aspect and conducting repeated studies, it was found that the ratio S is preferably 5% to 90%, more preferably 10% to 85%, and even more preferably 15% to 80%. Additionally, when a component with higher thermal conductivity than copper is disposed in the space 4a, if the ratio S is too small, the heat dissipation can only be slightly improved; conversely, if the ratio S is too large, the cost increases. For example, in terms of achieving the effect of improving heat dissipation while suppressing costs, the ratio S when a graphite sheet is disposed in the space 4a is preferably 0.1% to 50%, more preferably 0.3% to 45%, and even more preferably 0.5% to 40%.

[0036] The ratio A of the area of ​​the heat-conducting member 4 in close contact with the insulating layer 3 at the boundary surface relative to the area of ​​the insulating layer 3 (the area on the back side) of the heat-conducting member 4 can be calculated, for example, by using an ultrasonic flaw detection device (SAT). Specifically, after taking an image of the boundary surface with the insulating layer 3 using an ultrasonic flaw detection device (SAT) (the surface where the heat-conducting member 4 contacts the heat-conducting grease when it is coated, and the surface where the heat-conducting member 4 contacts the insulating layer 3 when it is not coated), an image can be obtained, for example, showing the portion of the heat-conducting member 4 in close contact with the object in black and the portion not in close contact in white. Then, by calculating the ratio [%] of the area of ​​the black portion relative to the area of ​​the insulating layer 3 side of the heat-conducting member 4 (the area on the back side), the ratio A can be calculated. Furthermore, for example, if air is contained in the heat-conducting grease or the insulating layer 3, a portion that is not in close contact with the heat-conducting member 4 will occur. Furthermore, due to the low thermal conductivity of air, if the non-sealed portion increases, heat becomes difficult to transfer from the heat conduction member 4 to the insulation layer 3. Repeated studies in this regard have shown that the difficulty of heat transfer from the heat conduction member 4 to the insulation layer 3 when the proportion A decreases is proportional to the amount of reduction in the value of proportion A. Based on these findings, proportion A is reflected in equation (1). Proportion A is preferably in the range of 80% to 100%.

[0037] The thermal conductivity λ of the insulating layer 3 can be calculated, for example, by laser flash method. Specifically, laser light is irradiated on one side of the insulating layer 3 and the temperature change on the other side is measured. The specific heat capacity and thermal diffusivity of the insulating layer 3 are calculated based on the behavior of the temperature change. The thermal conductivity can be calculated by the product of the specific heat capacity, thermal diffusivity, and density. Therefore, the density of the insulating layer 3 can be calculated, for example, by Archimedes' method, and the thermal conductivity λ of the insulating layer 3 can be calculated from there.

[0038] If the thermal conductivity λ of the insulating layer 3 increases, heat is more easily transferred from the insulating layer 3 to the substrate 2. However, thermal conductivity and insulation are generally inversely related. In particular, in insulating layers 3 using resin compositions, the tendency for insulation properties of the insulating layer 3 to be compromised increases as the thermal conductivity λ increases. Considering this aspect, repeated studies were conducted, and it was found that in order to balance thermal conductivity and insulation properties in insulating layers 3 using resin compositions, the thermal conductivity λ is preferably 0.2 [W / mK] to 30 [W / mK], more preferably 0.4 [W / mK] to 27 [W / mK], and even more preferably 1 [W / mK] to 24 [W / mK].

[0039] The thickness t of the insulating layer 3 can be measured, for example, by using an eddy current film thickness gauge.

[0040] Here, when the thickness t of the insulating layer 3 is small, heat from the heat-conducting member 4 is easily transferred to the substrate 2, while the insulation of the insulating layer 3 is compromised. Conversely, when the thickness t of the insulating layer 3 is large, the insulation of the insulating layer 3 is ensured, while heat from the heat-conducting member 4 is difficult to transfer to the substrate 2. In particular, in insulating layers 3 using resin compositions, the influence of thickness t on thermal conductivity and insulation becomes greater. Considering this aspect, repeated studies were conducted, and it was found that in order to balance thermal conductivity and insulation in insulating layers 3 using resin compositions, the thickness t of the insulating layer 3 is preferably 0.02 mm to 0.4 mm, more preferably 0.02 mm to 0.3 mm, and even more preferably 0.02 mm to 0.2 mm.

[0041] Regarding the research results, some are shown below. Furthermore, in Examples 1-10, Examples 12-15, and Comparative Examples 2-4, the working fluid and core are housed in the space 4a, and the heat-conducting member 4 functions as a heat-conducting plate. Additionally, in Example 11, a graphite sheet (thermal conductivity 1800 [W / mK]) is housed in the space 4a. Moreover, Comparative Example 1 uses a heat-conducting member 4 with a ratio S of 0 [%) (a copper heat-conducting member 4 without a space 4a is used). Furthermore, Examples 1-14 and Comparative Examples 1-3 use an insulating layer 3 utilizing a resin composition; Example 15 uses a ceramic substrate in the insulating layer 3; and Comparative Example 4 uses a glass epoxy board in the insulating layer 3. Regarding cost, size, and manufacturability in Tables 1-4 below, ○ indicates within the practical range, and × indicates outside the practical range. Regarding insulation and heat dissipation, ○ indicates improvement over previous results, △ indicates slight improvement, and × indicates poor performance.

[0042] [Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Longitudinal length of heat-conducting component [mm] 80 40 20 130 160 Lateral length of heat-conducting components [mm] 80 50 20 130 160 Thickness of heat-conducting components [mm] 2 1.8 2 2 2 The apparent volume V [mm^3] of a heat-conducting component 12800 3600 800 33800 51200 The percentage S of the space section [%] 31.3 31.3 31.1 31.1 31.1 The percentage (A) of the area where the heat-conducting component is in close contact with the insulating layer. 100 100 100 100 100 Thermal conductivity λ of the insulating layer [W / mK] 10 10 0.2 10 10 Insulation layer thickness t [mm] 0.12 0.12 0.02 0.12 0.12 The value of equation (1) 18.68 5.25 0.14 48.85 74.00 cost ○ ○ ○ ○ ○ size ○ ○ ○ ○ ○ Productivity ○ ○ ○ ○ ○ insulation ○ ○ ○ ○ ○ Heat dissipation ○ ○ ○ ○ ○

[0043] [Table 2] Example 6 Example 7 Example 8 Example 9 Example 10 Longitudinal length of heat-conducting component [mm] 80 80 80 80 80 Lateral length of heat-conducting components [mm] 80 80 80 80 80 Thickness of heat-conducting components [mm] 2 2 2 2 2 The apparent volume V [mm^3] of a heat-conducting component 12800 12800 12800 12800 12800 The percentage S of the space section [%] 31.3 31.3 10.0 50.0 50.0 The percentage (A) of the area where the heat-conducting component is in close contact with the insulating layer. 100 100 100 100 100 Thermal conductivity λ of the insulating layer [W / mK] 1 20 10 10 0.2 Insulation layer thickness t [mm] 0.12 0.12 0.12 0.12 0.02 The value of equation (1) 1.87 37.36 3.37 37.71 4.53 cost ○ ○ ○ ○ ○ size ○ ○ ○ ○ ○ Productivity ○ ○ ○ ○ ○ insulation ○ ○ ○ ○ ○ Heat dissipation ○ ○ ○ ○ ○

[0044] [Table 3] Example 11 Example 12 Example 13 Example 14 Example 15 Longitudinal length of heat-conducting component [mm] 40 40 40 40 40 Lateral length of heat-conducting components [mm] 50 50 50 50 50 Thickness of heat-conducting components [mm] 1.8 1.8 1.8 1.8 1.8 The apparent volume V [mm^3] of a heat-conducting component 3600 3600 3600 3600 3600 The percentage S of the space section [%] 1.3 31.3 31.3 31.3 31.3 The percentage (A) of the area where the heat-conducting component is in close contact with the insulating layer. 100 79 100 100 100 Thermal conductivity λ of the insulating layer [W / mK] 10 10 25 0.2 10 Insulation layer thickness t [mm] 0.12 0.12 0.12 0.01 0.5 The value of equation (1) 0.046 4.15 13.13 1.26 1.26 cost ○ ○ ○ ○ ○ size ○ ○ ○ ○ ○ Productivity ○ ○ ○ ○ ○ insulation ○ ○ △ △ ○ Heat dissipation ○ △ ○ ○ △

[0045] [Table 4] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Longitudinal length of heat-conducting component [mm] 40 80 80 40 Lateral length of heat-conducting components [mm] 50 80 80 50 Thickness of heat-conducting components [mm] 1.8 2 8 1.8 The apparent volume V [mm^3] of a heat-conducting component 3600 12800 51200 3600 The percentage S of the space section [%] 0 80 33.8 31.3 The percentage (A) of the area where the heat-conducting component is in close contact with the insulating layer. 100 100 100 100 Thermal conductivity λ of the insulating layer [W / mK] 10 10 10 0.25 Insulation layer thickness t [mm] 0.12 0.12 0.12 1.6 The value of equation (1) 0.00 76.32 83.84 0.01 cost ○ ○ × ○ size ○ ○ ○ ○ Productivity ○ ○ × ○ insulation ○ ○ × ○ Heat dissipation × × × △~×

[0046] As can be clearly seen by comparing Examples 1 to 15 with Comparative Examples 1 to 4, when Equation (1) is satisfied, the cost, size, and manufacturability of the laminate 1 are within the practical range, and the insulation and heat dissipation are slightly improved or enhanced compared to the previous examples. In particular, when Equations (1) to (3) are satisfied, the cost, size, and manufacturability are within the practical range, and the insulation and heat dissipation are also improved.

[0047] The present invention has been described above in one embodiment, but the present invention is not limited to this specific embodiment. Various modifications and alterations can be made within the scope of the spirit of the invention as described in the claims, unless otherwise specified in the description. Furthermore, the effects described in the embodiment are merely illustrative of the effects produced by the present invention and do not imply that the effects of the present invention are limited to those effects.

[0048] 1: Laminated body 2: Substrate 3: Insulation layer 4: Heat conduction components 4a: Space Department 5: Electronic components (heating elements)

Claims

1. A laminate, comprising a substrate, an insulating layer, and a heat-conducting member sequentially laminated, capable of conducting heat from a heating element from the heat-conducting member through the insulating layer to the substrate, wherein the heat-conducting member is made of copper and has a space on its inner side, wherein a member with a higher thermal conductivity than copper is disposed in the space, or a working fluid that is heated and evaporates and dissipates heat and condenses is disposed therein, and a core that permeates the working fluid to generate capillary force, and satisfies the following formula (1), 0.01<V×(S^1.5)×A×λ×t×10^(-9)75 ···(1) where, V: Apparent volume of the heat-conducting member [mm3] S: Percentage of the volume occupied by the space relative to the apparent volume of the heat-conducting member [%] A: Percentage of the area of ​​the heat-conducting member in close contact with the insulating layer at the boundary surface of the insulating layer relative to the area of ​​the insulating layer side of the heat-conducting member [%] λ: Thermal conductivity of the insulating layer [W / mK] t: Thickness of the insulating layer [mm], where V is 100 [mm3] to 60000 [mm3], and when a member with higher thermal conductivity than copper is disposed in the space, S is 0.1 [%] to 50 [%]; when the working fluid and the core are disposed in the space, S is 5 [%] to 90 [%], A is 80 [%] to 100 [%], λ is 0.2 [W / mK] to 30 [W / mK], and t is 0.02 [mm] to 0.4 [mm].

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