Heat sink integrated insulating circuit board and electronic device

Abstract

To provide a heat sink-integrated circuit board which can efficiently discharge heat from an equipped electronic component from a heat sink.SOLUTION: A heat sink-integrated insulation circuit substrate 10 includes: a heat sink 11; an insulation layer 12 formed in a top plate part 11A of the heat sink 11; and a circuit layer 13 formed in a surface of the insulation layer 12 which is opposite to the surface where the heat sink 11 is formed, the circuit layer having an installation surface 13A with an electronic component 3 installed therein. The circuit layer 13 is formed of cooper or copper alloy. When a component occupation ratio as the ratio of the occupied area of the electronic component 3 to the area of the installation surface 13A of the circuit layer 13 is denoted by X and the ratio λR / tR as the ratio of the thickness tR of the insulation layer 12 to the thermal conductivity λR of the insulation layer 12 is denoted by Y, the thickness tC of the circuit layer 13 is in the range of 0.7×(-5X-0.005Y+4.5)≤tC≤1.3×(-5X-0.005Y+4.5) when the component occupation ratio X is not larger than 0.6.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a heat sink integrated insulation circuit board including a heat sink, an insulation layer, and a circuit layer, and an electronic device.

Background Art

[0002] In various electronic devices such as power modules, LED modules, and thermoelectric modules, electronic components such as power semiconductor elements, LED elements, and thermoelectric elements are joined to an insulation circuit board in which a circuit layer made of a conductive material is formed on one surface of an insulation layer. As the insulation layer, those using ceramics or those using an insulating resin have been proposed.

[0003] In addition, in these insulation circuit boards, a heat sink is provided to dissipate heat from the mounted elements. For example, Patent Documents 1 and 2 propose a heat sink integrated insulation circuit board in which a heat sink and a circuit layer are insulated by an insulating resin layer.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above heat sink integrated insulation circuit board, heat generated from the electronic components mounted on the circuit layer is spread in the plane direction by the circuit layer, and the heat to the heat sink is transmitted through the insulation layer and dissipated by the heat sink. Here, by increasing the thickness of the circuit layer, heat from the electronic component is more likely to spread in the plane direction, but it becomes a thermal resistance in the thickness direction. Therefore, in order to efficiently dissipate heat from the mounted electronic component to the heat sink, it is necessary to optimize the thickness of the circuit layer.

[0006] This invention has been made in view of the above-described circumstances, and an object thereof is to provide a heat sink integrated insulating circuit board capable of efficiently dissipating heat from a mounted electronic component to a heat sink, and an electronic device.

Means for Solving the Problems

[0007] As a result of intensive studies by the inventors to solve such problems and achieve the above object, by defining an appropriate thickness of the circuit layer according to the occupied area of the electronic component in the circuit layer, it has been found that heat generated in the electronic component can be efficiently dissipated from the heat sink.

[0008] The present invention has been made based on the above findings. The heat sink integrated insulating circuit board of the present invention includes a heat sink, an insulating layer formed on the top plate portion of the heat sink, and a circuit layer formed on the surface of the insulating layer opposite to the heat sink. The heat sink integrated insulating circuit board has an electronic component mounted on the mounting surface of the circuit layer. The circuit layer is made of copper or a copper alloy. Let X be the component occupancy rate, which is the ratio of the occupied area of the electronic component to the area of the mounting surface of the circuit layer. Let t be the thickness of the insulating layer R and λ be the thermal conductivity of the insulating layer R and the ratio λ R / t R be Y. When the component occupancy rate X is in the range of 0.6 or less, the thickness t of the circuit layer C is in the range of 0.7×(-5X - 0.005Y + 4.5) ≦ t C ≦ 1.3×(-5X - 0.005Y + 4.5).

[0009] According to the heat sink integrated insulating circuit board of the present invention, the thickness t of the circuit layerC is the component occupancy ratio X, which is the ratio of the occupied area of the mounted electronic component to the area of the mounting surface of the circuit layer, and the thickness t of the insulating layer R and the thermal conductivity λ of the insulating layer R and the ratio Y = λ R / t R are within the range defined by the above formula, so it is possible to efficiently dissipate the heat generated by the electronic component from the heat sink.

[0010] Here, in the heat sink integrated insulating circuit board of the present invention, the thickness t of the insulating layer R is preferably in the range of 0.05 mm or more and 0.3 mm or less, and the thermal conductivity λ of the insulating layer R is preferably in the range of 3 W / (m·K) or more and 30 W / (m·K) or less. In this case, since the thickness and thermal conductivity of the insulating layer are within the above ranges, the heat on the circuit layer side can be transferred to the heat sink side, and the insulation between the circuit layer and the heat sink can be sufficiently ensured.

[0011] Further, in the heat sink integrated insulating circuit board of the present invention, it is preferable that the heat sink is made of copper or a copper alloy. In this case, since the heat sink is made of copper or a copper alloy, it has excellent thermal conductivity and can more efficiently dissipate the heat generated from the electronic component.

[0012] The electronic device of the present invention is characterized by including the above-described heat sink integrated insulating circuit board and an electronic component mounted on the mounting surface of the circuit layer of the heat sink integrated insulating circuit board. According to the electronic device having this configuration, as described above, since it includes a heat sink integrated insulating circuit board having excellent heat dissipation characteristics, it is possible to efficiently dissipate the heat generated from the electronic component, and it can be stably used even when the amount of heat generated from the electronic component increases.

Effects of the Invention

[0013] According to the present invention, it is possible to provide a heat sink integrated insulating circuit board capable of efficiently dissipating heat from mounted electronic components to a heat sink, and an electronic device.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that each of the embodiments shown below is specifically described to better understand the gist of the invention, and does not limit the present invention unless otherwise specified. Also, the drawings used in the following description may show the main parts enlarged for convenience of clearly understanding the features of the present invention, and the dimensional ratios of each component are not necessarily the same as the actual ones.

[0016] FIG. 1 shows a heat sink integrated insulation circuit board 10 which is an embodiment of the present invention and a semiconductor device 1 (electronic device) using this heat sink integrated insulation circuit board 10.

[0017] The semiconductor device 1 shown in FIG. 1 includes a heat sink integrated insulation circuit board 10 and an electronic component 3 joined via a solder layer 2 on one surface (the upper surface in FIG. 1) of the heat sink integrated insulation circuit board 10. In the present embodiment, the electronic component 3 is a semiconductor element.

[0018] The electronic component 3 is made of a semiconductor material such as Si. The solder layer 2 that joins the heat sink integrated insulation circuit board 10 and the electronic component 3 is, for example, a solder material of Sn - Ag system, Sn - Cu system, Sn - In system, or Sn - Ag - Cu system (so-called lead - free solder material).

[0019] The heat sink integrated insulating circuit board 10 includes a heat sink 11, an insulating layer 12 formed on one surface (the upper surface in FIG. 1) of the top plate portion 11A of the heat sink 11, and a circuit layer 13 formed on one surface (the upper surface in FIG. 1) of the insulating layer 12. And the above-described electronic component 3 is joined to the mounting surface 13A (the upper surface in FIG. 1) of the circuit layer 13.

[0020] The heat sink 11 includes a top plate portion 11A and heat radiation fins 11B protruding from the other surface (the lower surface in FIG. 1) of the top plate portion 11A. This heat sink 11 is made of a material having excellent thermal conductivity, and is composed of, for example, a metal such as copper or a copper alloy, aluminum or an aluminum alloy, a carbonaceous material, a composite material of a metal and a carbonaceous material, etc. In the present embodiment, it is preferable that the heat sink 11 (the top plate portion 11A and the heat radiation fins 11B) is made of copper or a copper alloy.

[0021] Note that the thickness of the top plate portion 11A is preferably 1 mm or more, more preferably 3 mm or more. On the other hand, the thickness of the top plate portion 11A is preferably 7 mm or less, more preferably 5 mm or less. Furthermore, the heat radiation fins 11B may have a pin fin structure or a comb-shaped structure.

[0022] The insulating layer 12 prevents electrical connection between the circuit layer 13 and the heat sink 11, and in this embodiment, it is made of an insulating resin. In this embodiment, in order to ensure the strength of the insulating layer 12 and ensure thermal conductivity, it is preferable to use a resin containing an inorganic material filler as the resin constituting the insulating layer 12. Here, as the filler, for example, alumina, boron nitride, aluminum nitride, etc. can be used. From the viewpoint of ensuring the thermal conductivity in the insulating layer 12, the content of the filler is preferably 50 mass% or more, more preferably 70 mass% or more. In addition, as the thermosetting resin, an epoxy resin, a polyimide resin, a silicone resin, etc. can be used. Here, if it is a silicone resin, the above-described filler can be contained in an amount of 70 mass% or more, and if it is an epoxy resin, the above-described filler can be contained in an amount of 80 mass% or more.

[0023] Here, in the present embodiment, the thickness t of the insulating layer 12 R is preferably in the range of 0.05 mm or more and 0.3 mm or less. Note that the thickness t of the insulating layer 12 R is more preferably 0.08 mm or more, and even more preferably 0.1 mm or more. On the other hand, the thickness t of the insulating layer 12 R is more preferably 0.25 mm or less, and even more preferably 0.2 mm or less.

[0024] In addition, the thermal conductivity λ of the insulating layer 12 R is preferably in the range of 3 W / (m·K) or more and 30 W / (m·K) or less. Note that the thermal conductivity λ of the insulating layer 12 R is more preferably 5 W / (m·K) or more, and even more preferably 8 W / (m·K) or more. On the other hand, the thermal conductivity λ of the insulating layer 12 R is more preferably 25 W / (m·K) or less, and even more preferably 20 W / (m·K) or less.

[0025] As shown in FIG. 11, the circuit layer 13 is formed by joining a metal piece 43 made of a metal having excellent conductivity to one surface of the insulating layer 12. As the metal piece 43, copper or a copper alloy, aluminum or an aluminum alloy, etc. can be used. In the present embodiment, a punched-out rolled plate of oxygen-free copper is used as the metal piece 43 constituting the circuit layer 13. In this circuit layer 13, a circuit pattern is formed, and one surface (the upper surface in FIG. 1) thereof is a mounting surface 13A on which the electronic component 3 is mounted.

[0026] And in the heat sink integrated insulating circuit board 10 of the present embodiment, the thickness t of the circuit layer 13 C is the component occupancy ratio X which is the ratio of the occupied area of the electronic component 3 to the area of the mounting surface of the circuit layer 13, and the thickness t of the insulating layer 12 R and the ratio Y = λ R of the insulating layer 12 to the thermal conductivity λ R / t R are set as follows. 0.7×(-5X - 0.005Y + 4.5) ≤ t C ≤ 1.3×(-5X - 0.005Y + 4.5) However, the component occupancy ratio X is 0.6 or less. Note that the value of t C is preferably closer to -5X - 0.005Y + 4.5, and may also be in the following range. 0.8×(-5X - 0.005Y + 4.5) ≤ t C ≤ 1.2×(-5X - 0.005Y + 4.5) 0.9×(-5X - 0.005Y + 4.5) ≤ t C ≤ 1.1×(-5X - 0.005Y + 4.5)

[0027] Hereinafter, the reason for defining the thickness t of the circuit layer 13 C as described above will be explained. The heat generated from the electronic component 3 mounted on the mounting surface 13A of the circuit layer 13 is spread in the plane direction in the circuit layer 13 with excellent thermal conductivity, transmitted to the heat sink 11 through the insulating layer 12, and dissipated from the heat dissipation fins 11B of the heat sink 11. Therefore, in order to efficiently dissipate the heat from the electronic component 3, it is necessary to reduce the thermal resistance in the thickness direction of the heat sink integrated insulating circuit board 10.

[0028] Here, FIGS. 2 to 8 show the results of thermal calculations of the thermal resistance in the thickness direction of heat sink integrated insulating circuit boards with various structures. In FIGS. 3, 5, 7, and 8, as the thermal calculation results, the relationship between the thickness of the circuit layer of the heat sink integrated insulating circuit board and the surface temperature of the electronic components mounted on the circuit layer is shown. The lower the surface temperature of the electronic components, the lower the thermal resistance in the thickness direction of the heat sink integrated insulating circuit board, indicating excellent heat dissipation characteristics.

[0029] FIGS. 2 and 3 show the calculation results when the component occupancy ratio X, which is the ratio of the occupied area of the electronic component 3 to the area of the mounting surface 13A of the circuit layer 13, is 1.0, that is, when the electronic component 3 is mounted on the entire mounting surface 13A of the circuit layer 13. The thickness t of the circuit layer 13 C As the thickness increases, the surface temperature of the electronic component rises, indicating that the thermal resistance in the thickness direction of the heat sink integrated insulating circuit board increases. Since the component occupancy ratio X is 1.0, in the circuit layer 13, there is no effect of spreading heat in the plane direction and heat is only transmitted in the thickness direction. As the thickness t of the circuit layer 13 C increases, the thermal resistance in the thickness direction of the heat sink integrated insulating circuit board increases.

[0030] FIGS. 4 and 5 show the calculation results when the component occupancy ratio X, which is the ratio of the occupied area of the electronic component 3 to the area of the mounting surface 13A of the circuit layer 13, is 0.59. The surface temperature of the electronic component is found to have a minimum value with respect to the thickness t of the circuit layer 13 C . Note that the lower the surface temperature of the electronic component, the lower the thermal resistance of the heat sink integrated insulating circuit board. Since the component occupancy ratio X is 0.59, in the circuit layer 13, heat is spread in the plane direction and also transmitted in the thickness direction. Therefore, by optimizing the thickness t of the circuit layer 13 C considering the effect of spreading heat in the plane direction and the thermal resistance in the thickness direction, it is possible to lower the thermal resistance in the thickness direction of the heat sink integrated insulating circuit board.

[0031] Figures 6 to 8 show the calculation results when the component occupancy ratio X, which is the ratio of the occupied area of the electronic component 3 to the area of the mounting surface 13A of the circuit layer 13, is 0.44. Here, in Fig. 7, thermal calculations were performed by changing the heat transfer coefficient of the heat sink 11. In Fig. 8, the thermal conductivity λ R of the insulating layer 12 was changed and thermal calculations were performed. The surface temperature of the electronic component is found to have a minimum value with respect to the thickness t C of the circuit layer 13. Note that the lower the surface temperature of the electronic component, the lower the thermal resistance of the heat sink integrated insulating circuit board.

[0032] Note that, as shown in Figs. 7(a) and (b), even when the heat transfer coefficient of the heat dissipation fin 11B is changed, the thickness t C of the circuit layer 13 at which the surface temperature of the electronic component (the thermal resistance of the heat sink integrated insulating circuit board) shows a minimum value does not change. Also, as shown in Figs. 8(c), (d), and (e), when the thermal conductivity λ R of the insulating layer 12 is changed, it is found that the thickness t C of the circuit layer 13 at which the surface temperature of the electronic component (the thermal resistance of the heat sink integrated insulating circuit board) shows a minimum value changes. It is presumed that this is because when the thermal resistance in the insulating layer 12 is large, it is necessary to sufficiently spread heat in the plane direction in the circuit layer 13.

[0033] From the above results of the thermal calculations, in order to improve the heat dissipation performance and reduce the thermal resistance of the heat sink integrated insulating circuit board, since heat needs to be sufficiently spread in the plane direction and transmitted in the thickness direction in the circuit layer 13, it is necessary to optimize the thickness t C of the circuit layer 13. And it was found that the appropriate value of the thickness of the circuit layer 13 is not greatly affected by the heat dissipation characteristics of the heat sink, but is affected by the thermal resistance in the insulating layer 12.

[0034] Therefore, in the heat sink integrated insulating circuit board 10 of the present embodiment, the thickness t C of the circuit layer 13 is, as described above, the component occupancy ratio X and the thickness t Rand the thermal conductivity λ of the insulating layer 12 R The ratio Y to it is Y = λ R / t R which is defined by As described above, the heat resistance in the thickness direction of the heat sink integrated insulating circuit board is clearly minimized by the thickness t C of the circuit layer 13 when the component occupancy X is 0.6 or less.

[0035] Here, in the actual semiconductor device 1, as shown in FIG. 9, the electronic components 3 are respectively mounted on the circuit layer 13 arranged in a circuit pattern. In the semiconductor device 1 shown in FIG. 9, the component occupancy X is calculated as X = B / A from the area of the mounting surface 13A of the circuit layer 13 (the total area of the region A in FIG. 9) and the occupied area of the electronic component 3 (the total area of the region B in FIG. 9). Note that the area of the circuit layer 13 on which the electronic component 3 is not mounted is not included in the region A. Also, in the present embodiment, the entire bottom surface of the electronic component 3 is joined to the circuit layer 13.

[0036] Next, a method for manufacturing the heat sink integrated insulating circuit board 10 according to the present embodiment will be described with reference to FIGS. 10 and 11.

[0037] (Resin composition disposing step S01) As shown in FIG. 11, a resin composition 42 containing an inorganic material filler, a resin, and a curing agent is disposed on one surface (the upper surface in FIG. 11) of the top plate portion 11A of the heat sink 11. In the present embodiment, the resin composition 42 is in the form of a sheet.

[0038] (Metal piece arranging step S02) Next, a plurality of metal pieces 43 that will form the circuit layer 13 are arranged in a circuit pattern on one surface (the upper surface in FIG. 11) of the resin composition 42.

[0039] (Pressing and heating step S03) Next, the heat sink 11, the resin composition 42, and the metal piece 43 are pressed and heated in the stacking direction by a pressing device, thereby curing the resin composition 42 to form the insulating layer 12, and joining the top plate portion 11A of the heat sink 11, the insulating layer 12, and the insulating layer 12 and the metal piece 43.

[0040] In this pressing and heating step S03, it is preferable that the heating temperature is in the range of 120°C or higher and 350°C or lower, and the holding time at the heating temperature is in the range of 10 minutes or longer and 180 minutes or shorter. Further, it is preferable that the pressing load in the stacking direction is in the range of 1 MPa or higher and 30 MPa or lower.

[0041] Here, the lower limit of the heating temperature is more preferably 150°C or higher, and even more preferably 170°C or higher. On the other hand, the upper limit of the heating temperature is more preferably 320°C or lower, and even more preferably 300°C or lower. The lower limit of the holding time at the heating temperature is more preferably 30 minutes or longer, and even more preferably 60 minutes or longer. On the other hand, the upper limit of the holding time at the heating temperature is more preferably 120 minutes or shorter, and even more preferably 90 minutes or shorter. The lower limit of the pressing load in the stacking direction is more preferably 3 MPa or higher, and even more preferably 5 MPa or higher. On the other hand, the upper limit of the pressing load in the stacking direction is more preferably 15 MPa or lower, and even more preferably 10 MPa or lower.

[0042] By the above-described steps, the heat sink integrated insulating circuit board 10 according to the present embodiment is manufactured.

[0043] According to the heat sink integrated insulating circuit board 10 of the present embodiment configured as described above, the thickness t C of the circuit layer 13 is the component occupancy ratio X, which is the ratio of the occupied area of the electronic component 3 to the area of the mounting surface 13A of the circuit layer 13, and the thickness t R of the insulating layer 12 and the thermal conductivity λ R of the insulating layer 12, and the ratio Y = λ R / t RSince it is defined within the following range defined by, the thermal resistance in the thickness direction of the heat sink integrated insulating circuit board 10 is reduced, and the heat generated by the electronic component 3 can be efficiently radiated from the heat sink 11. 0.7×(-5X - 0.005Y + 4.5) ≤ t C ≤ 1.3×(-5X - 0.005Y + 4.5) However, the component occupancy ratio X is 0.6 or less.

[0044] Also, in the heat sink integrated insulating circuit board 10 of the present embodiment, the thickness t of the insulating layer 12 R is in the range of 0.05 mm or more and 0.3 mm or less, and the thermal conductivity λ of the insulating layer 12 R is in the range of 3 W / (m·K) or more and 30 W / (m·K) or less, then the heat from the electronic component 3 can be sufficiently transferred to the heat sink 11 side, and the insulation between the circuit layer 13 and the heat sink 11 can be sufficiently ensured.

[0045] Also, in the heat sink integrated insulating circuit board 10 of the present embodiment, when the heat sink 11 is made of copper or a copper alloy, the heat sink 11 has excellent thermal conductivity, and the heat generated by the electronic component 3 can be radiated more efficiently.

[0046] Furthermore, according to the semiconductor device 1 (electronic device) of the present embodiment, since it includes the heat sink integrated insulating circuit board 10 of the present embodiment having excellent heat radiation characteristics, the heat generated by the electronic component 3 can be efficiently radiated, and even when the amount of heat generated from the electronic component 3 increases, it can be stably used.

[0047] As described above, the embodiments of the present invention have been described, but the present invention is not limited to this, and can be appropriately changed without departing from the technical idea of the invention. For example, in the present embodiment, the structure of the heat sink is not particularly limited, and it may have heat radiation fins of various structures, or the top plate portion may have a laminated structure. Also, in this embodiment, although the semiconductor element has been described as being mounted as an electronic component, the present invention is not limited to this, and other electronic components may be used.

Example

[0048] A confirmation experiment conducted to confirm the effectiveness of the present invention will be described.

[0049] First, as shown in Tables 1 to 7, the component occupancy ratio X, the thermal conductivity λ R and thickness t R of the insulating layer, and the thickness t C of the circuit layer were changed, and the thermal resistance in the thickness direction of the heat sink integrated insulating circuit board was calculated by thermal calculation. In Tables 1 to 7, the thermal resistance when the thickness of the circuit layer was used as a parameter was relatively evaluated with the thermal resistance when the thickness of the circuit layer was 0.05 mm as a reference (1.0).

[0050] ANSYS (manufactured by ANSYS), a general-purpose finite element method calculation software, was used for the thermal calculation. As a calculation model, a laminated structure of an electronic component, a solder layer, a circuit layer, an insulating layer, and a heat sink (only the top plate part) was assumed. As calculation conditions, it was assumed that heat was generated only from the electronic component, the surroundings were thermally insulated, and heat was radiated only from the lower part of the heat sink. That is, the heat generation amount was set for the electronic component, and the heat transfer coefficient was set only for the lower part of the heat sink. As specific values of the heat generation amount, physical property values, and heat transfer coefficient, the heat generation amount of the electronic component was 100 W, the thermal conductivity of the electronic component was 150 to 200 W / (m·K), the thermal conductivity of the solder layer was 30 to 50 W / (m·K), the thermal conductivity of the circuit layer was 400 W / (m·K), the thermal conductivity of the insulating layer was 3 to 30 W / mK, the thermal conductivity of the heat sink (top plate part) was 400 W / (m·K), and the heat transfer coefficient of the lower part of the heat sink was 5000 to 20000 W / (m 2 ·K) were set respectively. The size of the electronic component in plan view was 10 mm × 10 mm, and the size of the circuit layer was set so that the component occupancy ratio X was 0.2 to 1.0. The plan view sizes of the solder layer, circuit layer, insulating layer, and heat sink were the same, and the electronic component was arranged at the center of the solder layer. Also, assuming the state after sufficient time has elapsed after heat generation, the temperatures of each component were calculated by steady-state heat calculation.

[0051]

Table 1

[0052]

Table 2

[0053]

Table 3

[0054]

Table 4

[0055]

Table 5

[0056]

Table 6

[0057]

Table 7

[0058] As shown in Tables 1 to 7, in the example of the present invention where the thickness t C of the circuit layer is within the following range defined by the ratio Y = λ R / t R of the component occupancy X, the thickness t R of the insulating layer, and the thermal conductivity λ R of the insulating layer, it was confirmed that the thermal resistance was lower than that of the comparative example outside the range. 0.7×(-5X - 0.005Y + 4.5) ≤ t C ≤ 1.3×(-5X - 0.005Y + 4.5)

[0059] As a result of the above verification experiment, it was confirmed that according to the example of the present invention, it is possible to provide a heat sink integrated insulating circuit board capable of efficiently radiating heat from the mounted electronic components to the heat sink, and an electronic device.

Explanation of Signs

[0060] 1 Semiconductor device (electronic device) 3 Electronic component 10 Heat sink integrated insulating circuit board 11 Heat sink 11A Top plate part 12 Insulating layer 13 Circuit layer 13A Mounting surface

Claims

1. A heat sink integrated insulation circuit board comprising a heat sink, an insulating layer formed on the top plate portion of the heat sink, and a circuit layer formed on the surface of the insulating layer opposite to the heat sink, wherein an electronic component is mounted on the mounting surface of the circuit layer, the circuit layer is made of copper or a copper alloy, Let X be the component occupancy ratio, which is the ratio of the occupied area of the electronic component to the area of the mounting surface of the circuit layer, and let t Ｒ be the thickness of the insulating layer and λ Ｒ be the thermal conductivity of the insulating layer. When the ratio λ Ｒ / t Ｒ is defined as Y, In the range where the component occupancy ratio X is 0.6 or less, the thickness t of the circuit layer Ｃ is 0.7×(−5X − 0.005Y + 4.5) ≤ t Ｃ ≤ 1.3×(−5X − 0.005Y + 4.5) and is within the range of, characterized by a heat sink integrated insulation circuit board.

2. The thickness t of the insulating layer Ｒ is in the range of 0.05 mm or more and 0.3 mm or less, and the thermal conductivity λ of the insulating layer Ｒ is in the range of 3 W / (m·K) or more and 30 W / (m·K) or less, and the heat sink integrated insulating circuit board according to claim 1 is characterized by this.

3. The heat sink integrated insulation circuit board according to claim 1 or claim 2, characterized in that the heat sink is made of copper or a copper alloy.

4. An electronic device comprising the heat sink integrated insulation circuit board according to any one of claims 1 to 3, and an electronic component mounted on the mounting surface of the circuit layer of the heat sink integrated insulation circuit board.

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