JP2014099544A - Circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit board excellent in heat dissipation.SOLUTION: A circuit board 1 is used which includes: a printed board 10 including an insulating substrate provided with at least one through hole, a conductor pattern layer formed on both surfaces of the insulating substrate, a first metal plating layer covering an inner wall of the through hole and the conductor pattern layer formed on both surfaces of the insulating substrate, a metal thermally conductive member arranged in the through hole so as to be in close contact with the first metal plating layer, and a second metal plating layer formed on both surfaces of the insulating substrate so as to continuously cover the conductor pattern layer and an end surface of the thermally conductive member; an electronic component 21 provided at that position of one surface of the printed board 10 which faces the thermally conductive member, and thermally connected to the thermally conductive member via the second metal plating layer; and a radiator provided at that position of the other surface of the printed board which faces the thermally conductive member, and thermally connected to the thermally conductive member via the second metal plating layer.

Description

  The present invention relates to a circuit board having a heat dissipation mechanism.

In recent years, with the increase in output and performance of electronic devices, heat generation of electronic components such as semiconductor components disposed on a printed circuit board has become a problem.
On the other hand, as shown in the following Patent Document 1, a metal base substrate has conventionally been used as a substrate for realizing heat dissipation, workability, voltage resistance, and the like for a printed circuit board. In the printed circuit board of Patent Document 1, an insulating layer is provided on the surface of a metal base substrate, a conductive pattern is formed on the insulating layer, and an electronic component is provided on the conductive pattern. In addition, with the increase in output of electronic components, an insulating layer is provided between the electronic components and the metal base substrate.

  Patent Document 2 below proposes a printed circuit board in which a through hole is provided in a metal base substrate having an insulating layer formed on the surface, and a metal plating layer is provided so as to cover the inner wall surface of the through hole. . In the printed circuit board of Patent Document 2, a through hole is provided on the metal base substrate at a position where an electronic component is mounted. Thereby, the heat of the electronic component is dissipated not only through the metal base substrate but also through the through hole and the metal plating layer.

JP 60-7195 A JP 2001-189536 A

  However, in the printed circuit board of Cited Document 1, the heat of the electronic component is not easily transmitted to the metal base substrate because the insulating layer provided between the electronic component and the metal base substrate has low thermal conductivity. Even when the heat of the electronic component is transmitted to the metal base substrate, the other electronic components may be damaged by the heat diffused throughout the metal base substrate. Furthermore, even when a heat sink is connected to the back surface of the metal base substrate, a heat dissipation sheet or heat release grease provided between the metal base substrate and the heat dissipator to fix the metal base substrate and the heat dissipator. Since the thermal conductivity is low, the heat transmitted to the metal base substrate is difficult to be transmitted to the radiator.

Moreover, in the printed circuit board of the cited document 2, when the heat generation of the electronic component continues, the heat transmitted to the metal base substrate is not diffused and is saturated in the metal base substrate. In particular, such a problem becomes more conspicuous in a printed circuit board on which an electronic component through which a large current flows, such as an electronic component mounted on an automobile or the like.
In view of such a situation, the present invention intends to provide a circuit board excellent in heat dissipation.

The circuit board of the present invention includes an insulating substrate provided with at least one through hole,
A conductor pattern layer formed on both sides of the insulating substrate;
A first metal plating layer covering the inner wall of the through hole and the conductor pattern layer formed on both surfaces of the insulating substrate;
A metal heat conduction member disposed in close contact with the first metal plating layer in the through hole;
A second metal plating layer formed by continuously covering the conductive pattern layer and the end face of the heat conducting member on both surfaces of the insulating substrate;
A printed circuit board comprising:
An electronic component provided at a position facing the heat conducting member on one side of the printed circuit board and thermally connected to the heat conducting member via the second metal plating layer;
A radiator that is provided at a position facing the heat conducting member on the other surface of the printed circuit board and is thermally connected to the heat conducting member through the second metal plating layer;
It is characterized by providing.

  According to the printed circuit board of the present invention, since the electronic component, the heat conductive member, and the heat radiating member are connected without using a layer having low heat conductivity, the heat of the electronic component is directly transferred to the heat radiating member through the heat conductive member. Diffused. Also, the heat of the electronic component is less likely to be transmitted to the insulating substrate as compared to the heat conducting member, and the heat of the electronic component is less likely to diffuse to the insulating substrate.

  In the printed circuit board of the present invention, the heat dissipation of the electronic component is improved. Further, it is possible to prevent the heat of the electronic component from diffusing into the insulating substrate and damaging other electronic components.

It is sectional drawing which shows one structural example of the circuit board in the 1st Embodiment of this invention. It is sectional drawing which shows one structural example of the printed circuit board which comprises the circuit board in the 1st Embodiment of this invention. It is sectional drawing which shows an example of the manufacturing method of the circuit board in the 1st Embodiment of this invention. It is sectional drawing which shows the example of 1 structure of the circuit board in the 2nd Embodiment of this invention. It is sectional drawing which shows one structural example of the circuit board in the 3rd Embodiment of this invention. It is sectional drawing which shows one structural example of the printed circuit board which comprises the circuit board in the 3rd Embodiment of this invention.

Hereinafter, a circuit board according to an embodiment of the present invention will be described with reference to the accompanying drawings.
1. 1st Embodiment In 1st Embodiment, the circuit board provided with the heat radiator which consists of a heat sink provided with a several heat radiating fin is described.

(1-1) Configuration of Circuit Board FIG. 1 is a cross-sectional view showing a cross-sectional structure of the circuit board 1 according to the first embodiment of the present invention. As shown in FIG. 1, the circuit board 1 includes a printed board 10, an electronic component 21, and a heat sink 22. The electronic component 21 and the heat sink 22 are thermally connected to the printed circuit board 10. The non-electrode part 21a and the heat sink 22 of the electronic component 21 and the printed circuit board 10 are fixed via an adhesive layer 23 having thermal conductivity. As a result, the electronic component 21, the heat conducting member 15 inserted into the printed circuit board 10, and the heat sink 22 are connected without going through a layer having low heat conductivity, and the heat of the electronic component 21 passes through the heat conducting member 15. It diffuses directly into the heat sink 22.

  FIG. 2 is a cross-sectional view showing a cross-sectional structure of the printed circuit board 10. The printed circuit board 10 is an insulating substrate 11, a conductor pattern layer 12, a through hole 13, a through-hole plating layer 14 that is a first metal plating layer, a heat conductive member 15, and a second metal plating layer. And a surface plating layer 16. A circuit pattern 18 and a heat conduction pattern 17 are provided on the surface of the printed circuit board 10. The circuit pattern 18 is a layer in which the conductor pattern layer 12, the through-hole plating layer 14, and the surface plating layer 16 are integrally formed and are not thermally connected to the heat conducting member 15. The heat conduction pattern 17 is a layer in which the conductor pattern layer 12, the through-hole plating layer 14, and the surface plating layer 16 are integrally formed and are thermally connected to the heat conduction member 15. The heat conductive pattern 17 is formed in the insertion portion of the heat conductive member 15 of the printed board 10.

  The insulating substrate 11 has a single layer structure composed only of an insulating layer. The conductor pattern layer 12 is provided on both surfaces of the insulating substrate 11 and has a predetermined pattern shape. The insulating substrate 11 provided with the conductor pattern layer 12 is provided with a through hole 13 at a portion where the non-electrode portion 21a of the electronic component 21 is opposed. A through-hole plating layer 14 is formed on the inner wall of the through-hole 13. The through-hole plating layer 14 is formed so as to cover the inner wall of the through-hole 13 and the surface of the conductor pattern layer 12 formed on both surfaces of the insulating substrate 11. A heat conduction member 15 is press-fitted into the through-hole 13 provided with the through-hole plating layer 14. Surface plating layers 16 are formed on both surfaces of the insulating substrate 11 in which the heat conducting member 15 is inserted into the through holes 13. The surface plating layer 16 is formed so as to continuously cover the conductor pattern layer 12 and the end face of the heat conducting member 15 on each of the front and back surfaces of the insulating substrate 11.

As shown in FIG. 1, the non-electrode portion 21 a of the electronic component 21 is fixed to the heat conduction pattern 17 via the adhesive layer 23 on one surface of the printed board 10. Thereby, the electronic component 21 and the heat conductive member 15 are thermally connected. Further, the low potential side electrode portion 21 b and the high potential side electrode portion 21 c of the electronic component 21 are fixed to the circuit pattern 18 via the conductive adhesive layer 24 on one surface of the printed board 10. Thereby, the electronic component 21 and the circuit pattern 18 are electrically connected.
The heat sink 22 is fixed to the heat conductive pattern 17 via the adhesive layer 23 on the other surface of the printed circuit board 10. Thereby, the heat sink 22 and the heat conductive member 15 are thermally connected.

The insulating substrate 11 has a low conductivity, is excellent in flame retardancy, heat resistance, moisture resistance, dimensional stability, chemical resistance, and the like, and is made of a material suitable for a double-sided printed wiring board provided with a through-hole plating layer 14. It is preferable. Examples of the insulating substrate 11 include FR-4 (Flame Retardant Type 4), FR-5 (Flame Retardant Type 5), CEM-3 (Composite Epoxy Material Grade 3), and BT (Bismaleimide-Triazine) resin.
The conductive pattern layer 12 is made of a conventionally used metal material such as copper (Cu), iron (Fe), nickel (Ni), chromium (Cr), tungsten (W), aluminum (Al), gold (Au), silver ( Ag) or titanium (Ti), or an alloy mainly composed of these metal materials.

The through-hole plating layer 14 is made of, for example, copper and is formed by electroless copper plating.
The through-hole plating layer 14 may be a metal material other than copper, such as cobalt (Co), nickel, silver, or an alloy mainly composed of these metal materials. The thickness of the through-hole plating layer 14 is preferably 20 μm or more and 40 μm or less.
The heat conducting member 15 is preferably formed of a metal material having high heat conductivity and excellent workability. This is because the heat conduction member 15 is difficult to come off due to the contact between the metal materials, and the heat of the electronic component is well diffused through the heat conduction member 15. Examples of such a metal material include copper, nickel, and aluminum.

  The diameter of the heat conducting member 15 is slightly smaller than the diameter of the through-hole 13 and can be inserted into the through-hole 13. The volume of the heat conducting member 15 is preferably 101% or more and 110% or less with respect to the volume of the through hole 13 before the heat conducting member 15 is inserted. When the volume of the heat conductive member 15 is less than 101%, the heat conductive member 15 may not be sufficiently adhered to the through-hole plating layer 14 even if the heat conductive member 15 is press-fitted into the through hole 13 by press working. . Further, when the volume of the heat conducting member 15 is 110% or more, the insulating substrate 11 may be damaged by the pressure during the press working. Here, let the volume of the above-mentioned through-hole 13 be the volume after through-hole plating layer 14 formation.

The surface plating layer 16 is formed by, for example, electroless plating, electrolytic plating, ion plating, sputtering or vacuum deposition. The surface plating layer 16 is preferably made of a metal material selected in accordance with properties such as plating workability, corrosion resistance and strength desired to be imparted to the surface plating layer 16, and is particularly preferably made of copper.
The electronic component 21 is a heat-generating electronic component that is conventionally mounted on the printed circuit board 10. In particular, the electronic component 21 is a high-power component such as a high-intensity LED (Light Emitting Diode), a power MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), an insulated gate bipolar transistor (IGBT), or the like. In some cases, a higher heat dissipation effect can be obtained in the circuit board 1.

The heat sink 22 includes a main surface portion 22a and a plurality of heat radiation fins 22b extending substantially perpendicularly from the main surface portion. The heat sink 22 is preferably made of a metal material having high thermal conductivity, such as copper (Cu) or aluminum (Al). This is because heat dissipation is improved.
The adhesive layer 23 is a layer obtained by curing a material having high thermal conductivity, for example, a metal paste such as solder.
The adhesive layer 24 is a layer obtained by curing a conductive material, for example, a metal paste such as solder. The adhesive layer 23 and the adhesive layer 24 are preferably formed of a material such as solder having both high thermal conductivity and conductivity. This is because the manufacturing process becomes easy.

(1-2) Circuit Board Manufacturing Method FIGS. 3A to 3G are cross-sectional views showing manufacturing steps of the circuit board 1 of FIG. A method for manufacturing the circuit board 1 will be described below.
First, the conductor layer 12a is provided on both surfaces of the insulating substrate 11 by attaching, for example, copper foil. The conductor layer 12a is a uniform layer before pattern formation. Thereafter, a through hole 13 penetrating the insulating substrate 11 and the conductor layer 12a is formed (FIG. 3A). The through hole 13 is formed by cutting drilling or punching. Next, the through-hole plating layer 14 is formed on the surface of the inner wall of the through hole 13 and the surface of the conductor layer 12a provided on both surfaces of the insulating substrate 11 (FIG. 3B).

  The heat conduction member 15 having a shape protruding from the through hole 13 is inserted into the through hole 13 having the through hole plating layer 14 formed on the surface (FIG. 3C). As the heat conductive member 15 before press working, a columnar member having a diameter slightly smaller than the diameter of the through hole 13 after the through hole plating layer 14 is formed is used. This is to facilitate insertion into the through hole 13. The heat conducting member 15 inserted into the through hole 13 is pressed in the axial direction of the heat conducting member 15 with a press die 20 to plastically deform the heat conducting member 15 and press fit the heat conducting member 15 into the through hole 13 ( FIG. 3 (d)). Thereby, the heat conducting member 15 is in close contact with the through-hole plating layer 14 in the through hole 13.

  After press-fitting the heat conducting member 15, a surface plating layer 16 is formed (FIG. 3E). The surface plating layer 16 is formed so as to continuously cover the through-hole plating layer 14 and the end face of the heat conducting member 15. Subsequently, a part of the conductor layer 12a, the through-hole plating layer 14 and the surface plating layer 16 formed by lamination is removed by etching or the like to form a heat conduction pattern 17 and a circuit pattern 18 (FIG. 3 ( f)). 2 and 3 (f), the conductor pattern layer 12 is a conductor layer 12a formed in a predetermined pattern shape.

The heat conduction pattern 17 and the circuit pattern 18 are formed by the following procedure, for example. A photosensitive resin film is formed on the surface plating layer 16, and a part of the photosensitive resin film is exposed so that the photosensitive resin film at a position corresponding to a predetermined pattern shape remains. A part of the photosensitive resin film is removed by etching. Using the remaining photosensitive resin film as a mask, the conductor layer 12a, the through-hole plating layer 14, and the surface plating layer 16 are etched. Thereby, the printed circuit board 10 on which the heat conductive pattern 17 and the circuit pattern 18 are formed is obtained.
3A to 3F show the manufacturing process of the printed circuit board 10. In practice, a collective printed circuit board in which a plurality of printed circuit boards 10 are continuously formed is manufactured. Moreover, the process of separating each printed circuit board 10 is provided after the process of FIG. Thereby, a plurality of printed circuit boards 10 are formed simultaneously.

Subsequently, the electronic component 21 is fixed to the heat conduction pattern 17 and the circuit pattern 18 on one surface of the printed board 10 through the adhesive layer 23 and the adhesive layer 24. A heat conductive adhesive is attached on the heat conductive pattern 17, and a conductive adhesive is attached on the circuit pattern 18. The heat conductive adhesive and the non-electrode portion 21a of the electronic component 21 are in contact with each other, and the conductive adhesive and the low potential side electrode portion 21b and the high potential side electrode portion 21c of the electronic component 21 are in contact with each other. The electronic component 21 is disposed. By solidifying the heat conductive adhesive and the conductive adhesive, the adhesive layer 23 and the adhesive layer 24 are formed (FIG. 3G).
Similarly, the heat sink 22 is fixed to the heat conduction pattern 17 on the other surface of the printed circuit board 10 through the adhesive layer 23 (FIG. 3G). Thereby, the electronic component 21, the heat conductive member 15, and the heat sink 22 are thermally connected without going through a layer having low heat conductivity such as a resin layer.

  In the circuit board 1 manufactured as described above, the heat conductivity of the heat conductive member 15 is sufficiently higher than the heat conductivity of the resin material that is a part of the material forming the insulating substrate 11. For example, the thermal conductivity of copper, which is an example of a metal material forming the heat conducting member 15, is about 380 [W / mK]. Moreover, the thermal conductivity of the epoxy resin which is the main material of FR-4 which is an example of the insulating substrate 11 is about 0.3 [W / mK]. For this reason, the heat of the electronic component is easily transmitted to the heat conducting member 15 and is not easily transmitted to the insulating substrate 11. That is, the heat of the electronic component 21 is efficiently diffused to the heat sink 22 via the heat conducting member 15. In addition, since the heat of the electronic component 21 is not easily diffused into the insulating substrate 11 having a low thermal conductivity, other electronic components are not easily damaged by the heat of the electronic component 21.

Further, the expansion coefficient of the metal heat conduction member 15 is close to the expansion coefficient of the insulating substrate 11 described above. For this reason, the thermal expansion of the heat conducting member 15 and the insulating substrate 11 causes damage such as cracks in the mounting components such as the printed circuit board 10 and the electronic component 21, the adhesive layer 23 connecting the printed circuit board 10 and the electronic component 21, and the like. It also has the effect of being difficult.
Further, the heat conductive member 15 is in close contact with the through-hole plating layer 14 formed on the inner wall of the through hole 13, and the end surface of the heat conductive member 15 is covered with the surface plating layer 16 in a lid shape. For this reason, the heat conduction member 15 is firmly held in the through hole 13, and the electronic component 21 and the heat sink 22 are not easily detached or damaged due to the heat conduction member 15 moving up and down in the through hole 13.

2. Second Embodiment In the second embodiment, a circuit board provided with a heat radiating body composed of an exterior body that covers a printed circuit board and an electronic component will be described.
(2-1) Configuration of Circuit Board The circuit board according to the second embodiment includes an exterior body that houses a printed circuit board and an electronic component as a heat radiator. The circuit board of the second embodiment is the same as the circuit board of the first embodiment except for the outer package. For this reason, below, only an exterior body is explained.

FIG. 4 is a sectional view showing a sectional structure of the circuit board 31 according to the second embodiment of the present invention. As shown in FIG. 4, the circuit board 31 includes a printed circuit board 10, an electronic component 21, and an exterior body 32. In the circuit board 31 shown in FIG. 4, parts common to the circuit board 1 of the first embodiment (each part other than the exterior body 32) are denoted by the same reference numerals as in FIG.
The exterior body 32 is a casing, a component cover, or the like that accommodates a printed circuit board and electronic components inside. The exterior body 32 is thermally connected to the printed circuit board 10 via the adhesive layer 23. Thereby, the electronic component 21, the heat conductive member 15, and the exterior body 32 are connected without a layer having low thermal conductivity, and the heat of the electronic component 21 is diffused directly to the exterior body 32 through the heat conductive member.

A plurality of heat conducting members 15 are connected to the exterior body 32. This is because if the electronic component 21 and the heat conducting member 15 are connected only thermally, the plurality of electronic components 21 may not be short-circuited via the exterior body 32.
The package 32 is formed of, for example, a metal material having a high thermal conductivity, a ceramic having a high thermal conductivity, or two or more materials selected from these materials. Examples of the metal material include copper (Cu) and aluminum (Al). When the exterior body 32 is formed of a metal material, it is preferable because high heat dissipation is obtained. Examples of the ceramic include aluminum nitride (AlN) and silicon carbide (SiC). Moreover, the exterior body 32 may be formed with the resin material etc. with which the ceramic fiber was mixed.

(2-2) Circuit Board Manufacturing Method The printed circuit board 10 is manufactured by the same method as that in the first embodiment (FIGS. 3A to 3F). Further, the electronic component 21 is fixed to the printed circuit board 10 by the same method as in the first embodiment.
The exterior body 32 is fixed to the printed circuit board as follows. A printed circuit board 10 having an electronic component 21 mounted on one surface is prepared. A heat conductive adhesive is adhered on the heat conductive pattern 17 on the other surface of the printed circuit board 10. The printed circuit board 10 is accommodated in the exterior body 32, and the inner wall of the exterior body 32 and the printed circuit board 10 are brought into close contact with each other through a heat conductive adhesive. By forming the adhesive layer 23 by solidifying the heat conductive adhesive, the printed circuit board 10 on which the electronic component 21 is mounted and the exterior body 32 are fixed, and the circuit board 31 is obtained.

  The circuit board 31 of the second embodiment includes an exterior body 32 having a large heat dissipation area as a heat dissipation body. For this reason, the heat of the electronic component 21 is radiated on the entire surface of the exterior body 32 through the heat conducting member 15. In addition, since the exterior body 32 has a large heat radiation area, even when it is formed of a resin material having a lower thermal conductivity than a metal material, a certain heat radiation effect can be obtained.

3. Third Embodiment In the third embodiment, a circuit board is described in which a multilayer board having a conductor layer inside the insulating board is used as the insulating board.
(3-1) Configuration of Circuit Board The circuit board according to the third embodiment includes a multilayer substrate in which a conductor layer and an insulating layer are laminated in a plurality of layers as an insulating substrate. The circuit board according to the third embodiment includes a heat conducting member that serves both as an electrical connection between the electronic component and the power ground layer of the printed circuit board inner layer and the heat dissipation of the electronic component.

  FIG. 5 is a cross-sectional view showing a cross-sectional structure of a circuit board 51 according to the third embodiment. FIG. 6A is a cross-sectional view showing a cross-sectional structure of the printed circuit board 40 of the circuit board 51. FIG. 6B is a cross-sectional view showing a cross-sectional structure of the conductor layer 41 b portion of the printed circuit board 40. FIG. 6A is a cross-sectional view showing a cross section taken along line aa of the printed circuit board 40 in FIG. FIG. 6B is a cross-sectional view showing a cross section taken along the line bb of the printed circuit board 40 in FIG. In the cross-sectional views of the circuit board 51 shown in FIG. 5 and the printed circuit board 40 shown in FIGS. 6A and 6B, a portion common to the circuit board 1 of the first embodiment (except for the multilayer board 41) The same reference numerals as those in FIG.

As shown in FIG. 5, the circuit board 51 includes a printed board 40, an electronic component 21, and a heat sink 22. Hereinafter, the printed circuit board 40 will be described.
As shown in FIG. 6A, the printed circuit board 40 includes a multilayer substrate 41 that is an insulating substrate, a conductor pattern layer 12, a through-hole 13, a through-hole plating layer 14, a heat conduction member 15, and surface plating. Layer 16. The through hole 13 is provided in a part of the multilayer substrate 41 facing the low potential side electrode portion 21 b of the electronic component 21. The heat conducting member 15 is press-fitted into the through hole 13.

  On one surface of the printed circuit board 40, a heat conduction pattern 47 to which the low potential side electrode portion 21b of the electronic component 21 is fixed, and a circuit to which the non-electrode portion 21a and the high potential side electrode portion 21c of the electronic component 21 are fixed. A pattern 18 is formed. Further, a heat conductive pattern 47 to which the heat sink 22 is fixed is formed on the other surface of the printed circuit board 40. The heat conduction pattern 47 has the same configuration as the heat conduction pattern 17. The low potential side electrode portion 21b of the electronic component 21 is connected to the heat conductive pattern 47 through an adhesive layer 43 made of solder or the like having conductivity and heat conductivity.

The multilayer substrate 41 includes an insulating layer 41a, and a conductor layer 41b and a conductor layer 41c stacked via the insulating layer 41a.
The insulating layer 11a is made of, for example, FR-4. FR-4 is preferable because it is excellent in formability of the multilayer laminated structure and has properties suitable for cutting drilling and punching for forming the through hole 13.

The conductor layer 41b is in contact with the heat conducting member 15 through the through-hole plating layer 14, as shown in FIG. 6 (b). Thereby, the low potential side electrode portion 21b of the electronic component 21 and the conductor layer 41b are electrically connected.
At this time, the conductor layer 41b has a shape in which surrounding patterns in the vicinity of the heat conducting member 15 are partially connected. Thereby, the electrical connection between the electronic component 21 and the conductor layer 41b is maintained, and the heat of the electronic component 21 is prevented from diffusing to the entire conductor layer 41b via the heat conducting member 15.

The conductor layer 41c is electrically connected to the circuit pattern 18 on the surface of the printed circuit board 40 by a through-hole plating layer (not shown). The conductor layer 41 c has a predetermined pattern shape, and improves the mounting density on the circuit board 51.
The conductor layer 41b and the conductor layer 41c are conventionally used metal materials such as copper (Cu), iron (Fe), nickel (Ni), chromium (Cr), tungsten (W), aluminum (Al), and gold (Au). , Silver (Ag), titanium (Ti), or the like, or an alloy mainly composed of these metal materials.

  In the circuit board 51 of the third embodiment, the heat conducting member 15 thermally connects the electronic component 21 and the heat sink 22 and electrically connects the electronic component 21 and the conductor layer 41b. Thus, the heat conducting member 15 may have both the role of performing thermal diffusion to the back surface of the printed board 40 and the role of electrical connection with the conductor layer 41b that is the inner layer of the printed board 40.

DESCRIPTION OF SYMBOLS 1,31,51 ... Circuit board 10, 40 ... Printed circuit board 11 ... Insulation board 12 ... Conductive pattern layer 12a ... Conductive layer 13 ... Through-hole 14 ... Through-hole plating Layer (first metal plating layer)
15 ... Thermally conductive member 16 ... Surface plating layer (second metal plating layer)
17, 47 ... Thermal conduction pattern 18 ... Circuit pattern 20 ... Press die 21 ... Electronic component 21a ... Non-electrode part 21b ... Low potential side electrode part 21c ... High potential Side electrode 22 ... Heat sink 22a ... Main surface 22b ... Radiation fins 23, 24 ... Adhesive layer 32 ... Exterior body 41 ... Multilayer substrate 41a ... Insulating layer 41b, 41c ..Conductive layer 43 ... Adhesive layer

Claims (5)

An insulating substrate provided with at least one through hole;
A conductor pattern layer formed on both surfaces of the insulating substrate;
A first metal plating layer covering the inner wall of the through hole and the conductor pattern layer formed on both surfaces of the insulating substrate;
A metal heat conduction member disposed in close contact with the first metal plating layer in the through hole;
A second metal plating layer formed by continuously covering the conductive pattern layer and the end face of the heat conducting member on both surfaces of the insulating substrate;
A printed circuit board comprising:
An electronic component which is provided at a position facing the heat conducting member on one surface of the printed circuit board and is thermally connected to the heat conducting member via the second metal plating layer;
A heat dissipating member provided at a position facing the heat conducting member on the other surface of the printed circuit board and thermally connected to the heat conducting member via the second metal plating layer;
A circuit board comprising: The circuit board according to claim 1, wherein the electronic component and the heat radiating body and the second metal plating layer are fixed via an adhesive layer having thermal conductivity. The circuit board according to claim 1, wherein the heat radiator is a heat sink including a plurality of heat radiation fins. The circuit board according to claim 1, wherein the heat radiating body is an exterior body that sheathes the printed circuit board and the electronic component. The circuit board according to any one of claims 1 to 4, wherein the electronic component is at least one of a high-brightness LED, a power MOSFET, and an insulated gate bipolar transistor.

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