JP2023056936A - Electronic circuit substrate and manufacturing method for the same - Google Patents

Abstract

To provide an electronic circuit substrate excellent in substantial heat conducting property in the thickness direction of the substrate and to provide a manufacturing method for the same that can be manufactured efficiently.SOLUTION: The electronic circuit substrate includes a substrate on which a through hole is formed and a flexible heat conductive body inserted into the through-hole. The heat conductive body is in contact with a different member on both sides of the through-hole in the depth direction. The heat conductive body preferably has anisotropic heat conducting properties. The heat conductive body is preferably composed of a material including scaled graphite.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electronic circuit board and a method for manufacturing an electronic circuit board.

In recent years, with the miniaturization of electronic components (heating elements), the heat generated by the electronic components placed on the substrate is locally transmitted to the substrate, so the heat from the heating element can be dissipated more efficiently. There is a demand for a heat dissipation structure that allows heat to be dissipated from (see, for example, Patent Document 1).

For example, as shown in FIG. 19, a conventional heat dissipation structure 220 includes a semiconductor device (heat generating element) 210, a substrate (support) 211, a solder layer 212a, a heat spreader 213, and a copper inlay (columnar body) 214. , an insulating layer 215 and a heat sink 216 . A plurality of columnar copper inlays 214 are arranged to be embedded from the first surface 211a to the second surface 211b of the substrate 211 . Since the copper inlay 214 serves as a heat transfer path, the heat generated in the semiconductor device 210 can be efficiently transferred from the first surface 211a side to the second surface 211b side.

However, the contact between the copper inlay 214, the heat spreader 213, and the heat sink 216 is a contact between hard surfaces, in other words, a point contact due to minute unevenness existing on the surface, so sufficient adhesion is ensured. However, the substantial heat conductivity in the thickness direction of the substrate 211 could not be made sufficient.

In some cases, grease is applied to the surface where the heat dissipating member and the heating element are thermally connected in order to prevent the formation of an air layer serving as a heat insulating layer at the interface. However, general grease does not have high thermal conductivity. Therefore, diamond grease in which diamond having relatively high thermal conductivity is dispersed is also used (see, for example, Patent Document 2).
However, diamond grease is expensive. Moreover, even when diamond grease is used, it has been difficult to obtain sufficient thermal conductivity.

Japanese Patent No. 6551566 Japanese Patent Publication No. 2017-530220

An object of the present invention is to efficiently provide an electronic circuit board having substantially excellent thermal conductivity in the thickness direction of the substrate, and an electronic circuit board having substantially excellent thermal conductivity in the thickness direction of the substrate. To provide a method for manufacturing an electronic circuit board that can be manufactured.

The electronic circuit board of the present invention comprises a board having through holes formed therein,
and a flexible thermal conductor inserted into the through-hole,
The heat conductor is in contact with different members on both sides of the through-hole in the depth direction.

The method for manufacturing an electronic circuit board of the present invention comprises:
preparing a substrate having through holes;
a step of joining and soldering an electronic component to the portion of the substrate provided with the through hole;
inserting a flexible thermal conductor into the through-hole;
and fixing a cooling unit to the surface of the substrate opposite to the surface on which the electronic component is provided so as to be in contact with the heat conductor.

According to the present invention, an electronic circuit board having substantially excellent thermal conductivity in the thickness direction of the substrate and an electronic circuit board having substantially excellent thermal conductivity in the thickness direction of the substrate can be efficiently manufactured. It is possible to provide a method for manufacturing an electronic circuit board that can be manufactured.

1 is a cross-sectional view schematically showing an example of an electronic circuit board of the present invention; FIG. It is a perspective view which shows an example of a thermal conductor typically. It is sectional drawing which expands the part of the thermally-conductive part and laminated|stacked laminated|stacked, and shows typically. FIG. 3 is a plan view schematically showing an example of a heat conducting portion that constitutes a heat conductor; FIG. 4 is a schematic partially exploded perspective view showing a plurality of laminated heat conducting parts in an exploded manner; FIG. 2 is a conceptual diagram of an example of a cured product of a curable resin material forming a joint; FIG. 3 is a cross-sectional view schematically showing a sheet for forming a heat conducting portion made of flake graphite. FIG. 4 is a cross-sectional view schematically showing a state in which a composition for forming joints is applied to a sheet for forming a thermally conductive portion provided with recesses. FIG. 4 is a diagram schematically showing an example of an apparatus used in the bonding portion forming composition application step and the winding step. It is a figure which shows typically the incision body obtained by the incision process. FIG. 10 is a diagram schematically showing a state in which the incision body is pressed to increase the flatness of the incision body. It is a figure which shows the mode of a cutting process typically. It is a perspective view which shows another example of a heat conductor typically. 14 is a longitudinal sectional view of the heat conductor shown in FIG. 13; FIG. FIG. 4 is a cross-sectional view schematically showing another example of the electronic circuit board of the present invention; FIG. 4 is a plan view schematically showing another example of the electronic circuit board of the present invention; It is a figure which shows typically another example of the electronic circuit board of this invention, (A) is sectional drawing, (B) is a top view. It is a sectional view showing typically an example of the manufacturing method of the electronic circuit board of the present invention. It is a sectional view showing typically an example of the heat dissipation structure of the conventional electronic parts.

Preferred embodiments of the present invention are described in detail below.
[1] Electronic Circuit Board First, the electronic circuit board of the present invention will be described.
FIG. 1 is a cross-sectional view schematically showing an example of the electronic circuit board of the present invention.

In addition, in the drawings referred to in this specification, in order to make it easier to understand the relationship between each member, a part may be reduced or enlarged, and the size between each member shown in the drawings may be reduced or enlarged. The ratio does not represent the size ratio between the actual members. In this specification, the term "natural state" refers to a state in which no external force other than gravity is applied, and in particular, a state in which no external force other than gravity has been applied within 24 hours. say. Moreover, it is preferable that there is no history of applying a stress of 0.1 MPa or more after manufacturing the heat conductor. In addition, the measurements and treatments described in this specification are assumed to be performed at 20° C. unless temperature conditions are specified.

The electronic circuit board 100 includes a substrate 110 in which a through hole 111 is formed, and a flexible thermal conductor 1 inserted into the through hole 111 . The heat conductor 1 is in contact with different members on both sides of the through-hole 111 in the depth direction.

Since the heat conductor 1 has flexibility, the surfaces of the heat conductor 1 and the members that come into contact with the heat conductor 1 can be brought into contact with each other. In other words, sufficient adhesion can be secured, and substantial heat conductivity from the member to the heat conductor 1 can be made excellent.
As a result, the electronic circuit board 100 has excellent substantial thermal conductivity in the thickness direction of the board 110 .

In the illustrated configuration, the substrate 110 has a through-hole that penetrates in the thickness direction as the through-hole 111 to which the heat conductor 1 is applied. The through hole 111 to be applied may have a non-penetrating through hole that does not penetrate through the substrate 110 in the thickness direction instead of the penetrating through hole. Further, the substrate 110 may have non-penetrating through-holes as well as penetrating through-holes. In the following description, the case where the substrate 110 has a penetrating through-hole as the through-hole 111 to which the heat conductor 1 is applied will be mainly described.

For example, the thermal conductor 1 can be in contact with a high-temperature member on one side 110a of the substrate 110 and in contact with a heat dissipation member on the other side 110b of the substrate 110 . As a result, the heat transfer member for transferring the heat of the high-temperature member to the heat-dissipating member and efficiently dissipating heat from the heat-dissipating member contacts the object to be heated and the high-temperature member whose temperature is higher than that of the object to be heated. It is used as a heat transfer member or the like for transferring heat energy from a high temperature member to an object to be heated and efficiently heating the object to be heated.

In the following description, the case where the heat conductor 1 is used in contact with at least part of the surface of the high-temperature member, which is a heating element, and at least part of the surface of the heat radiating member will be mainly described.

The high-temperature member is not particularly limited as long as it becomes hotter than the surrounding atmosphere, and examples thereof include various electronic parts, electric parts, etc. More specifically, central processing of a computer. Equipment (CPU), image processing arithmetic processor (GPU), power semiconductor element (power device), FPGA, ASIC, SoC of smartphone, DSP and microcomputer of embedded equipment, or semiconductor element such as transistor.

The high-temperature member preferably has a maximum surface temperature of 40° C. or higher and 250° C. or lower, more preferably 50° C. or higher and 200° C. or lower, and even more preferably 60° C. or higher and 180° C. or lower.
When the heat conductor 1 is applied to such a high-temperature member, heat conduction and heat dissipation can be performed more preferably, and the effects of the present invention are exhibited more remarkably.

In the electronic circuit board 100 shown in FIG. 1, for example, the power semiconductor element 120 is arranged on one side 110a of the board 110, and the cooling unit 130 is arranged on the other side 110b of the board 110.
The thermal conductor 1 is in contact with the power semiconductor element 120 on one side 110 a of the substrate 110 and is in contact with the cooling unit 130 on the other side 110 b of the substrate 110 .

In the electronic circuit board 100, for example, the heat conductor 1 is arranged and thermally coupled between the power semiconductor element 120 as a high temperature member that is a heating element and the cooling unit 130 that is a heat dissipation member. At this time, the thermal conductor 1 having flexibility is inserted into the through hole 111 while being pressed in the thickness direction of the substrate 110, for example. In other words, the thermal conductor 1 is arranged between the power semiconductor element 120 and the cooling unit 130 while being pressed in the thickness direction of the substrate 110, for example.

The power semiconductor element 120 tends to generate a particularly large amount of heat among the above-described electronic components and electrical components. can.

As described above, the heat conductor 1 is made of a material with excellent thermal conductivity, is also excellent in flexibility, and is excellent in conformability to the surfaces of the high temperature member and the heat radiating member. Therefore, even if the surfaces of the high-temperature member and the heat-dissipating member have relatively large unevenness, the heat conductor 1 can be in close contact with these members, and the interfacial thermal resistance can be kept low. Substantial thermal conductivity from element 120 to thermal conductor 1 and from thermal conductor 1 to cooling unit 130 can be excellent.
As a result, the heat from the power semiconductor element 120, which is a high-temperature member, can be effectively radiated, and the occurrence of problems such as failure and malfunction of the power semiconductor element 120 due to heat can be suppressed. product life can be extended.

The following description will focus on the case where the thermal conductor 1 contacts the power semiconductor element 120 on one side 110a of the substrate 110 and contacts the cooling unit 130 on the other side 110b of the substrate 110. do.

[1-1] Substrate The substrate 110 is a plate-like member that supports the power semiconductor element 120 and the cooling unit 130 . The substrate 110 is not particularly limited, but for example, a printed wiring board or the like commonly used for electronic circuit boards can be used.

The substrate 110 is, for example, a laminated substrate. Thereby, the electronic circuit board 100 can be highly integrated.
The thickness of the substrate 110, that is, the length indicated by T1 in FIG. 1 is not particularly limited, but is preferably 1 mm or more and 6 mm or less, and more preferably 2 mm or more and 5 mm or less.
As a result, the above-described effects of the present invention are exhibited more remarkably.
In this specification, the "thickness of the substrate 110" refers to the thickness of the portion of the substrate 110 where the through holes 111 are provided.

[1-1-1] Through Holes Through holes 111 are formed in the substrate 110 .
The through holes 111 are recesses provided in the thickness direction of the substrate 110 . In particular, in the illustrated configuration, the through holes 111 are holes drilled through the substrate 110 . By inserting the thermal conductor 1 into the through hole 111, the thermal conductivity between both surfaces of the substrate 110, in other words, in the thickness direction of the substrate 110 can be improved.

The shape of through hole 111 is not particularly limited, and is appropriately set according to the shapes of power semiconductor element 120 and cooling unit 130 arranged on substrate 110 . The shape of the through hole 111 can be set, for example, to have the same shape as the power semiconductor element 120 but smaller than the power semiconductor element 120 . Examples of the shape of the through-hole 111 when viewed from above and the cross-sectional shape of the through-hole 111 include circular, elliptical, polygonal, and combinations thereof. The vertical cross-sectional shape of the through hole 111 may have a constant width in the thickness direction of the substrate 110, or may have a portion whose width changes depending on the thickness of the substrate 110. There may be.

When the shape of the through-hole 111 when viewed from above, or the cross-sectional shape of the through-hole 111 is polygonal, for example, quadrangular, the maximum length of one side should be 5 mm or more and 15 mm or less. is preferred, and 7 mm or more and 10 mm or less is more preferred. Thereby, the above effect can be made more remarkable.

When the through-hole 111 has a shape when viewed from above and the cross-sectional shape of the through-hole 111 is substantially circular, the diameter of the circle is preferably within the above range. When the shape of the end and the cross-sectional shape of the through hole 111 are substantially elliptical, the length of the major axis of the ellipse is preferably within the above range. be prominent.

The size of the through hole 111 may or may not be constant in the thickness direction of the substrate 110 . When the through-hole 111 has portions with different sizes in the thickness direction of the substrate 110, the length at the portion where the length of one side of the through-hole 111, the length of the diameter, and the length of the long axis are maximum is , is preferably a value within the above range.

For example, in the illustrated configuration, the shape and size of the through holes 111 are constant in the thickness direction of the substrate 110 . As a result, the thermal conductivity in the thickness direction of the substrate 110 due to the thermal conductor 1 inserted into the through hole 111 can be kept constant, and the effects of the present invention can be made more remarkable. In addition, since the steps of forming the through holes 111 in the substrate 110 and inserting the heat conductors 1 into the through holes 111 can be suitably performed, it is advantageous in terms of manufacturing.

An insulating layer (not shown) may be formed on the inner wall surface of the through hole 111 .
As a result, it is possible to prevent the occurrence of problems such as an electrical short circuit in the electronic circuit.

[1-2] Power Semiconductor Element The power semiconductor element 120 is a semiconductor element (power device) for power control. Such power semiconductor elements 120 include, for example, rectifier diodes, power transistors (power MOSFETs, insulated gate bipolar transistors (IGBT)), thyristors, gate turn-off thyristors (GTO), and triacs.

The power semiconductor element 120 is fixed on one surface 110a of the substrate 110 by solder 121, for example.
As a result, the bonding strength between the substrate 110 and the power semiconductor element 120 can be improved, the electrical conductivity can be ensured more reliably, and the power semiconductor element 120 can be attached to the power semiconductor element 120 when the power semiconductor element 120 is fixed. It is possible to more reliably prevent damage or the like from occurring. Moreover, the productivity of the electronic circuit board 100 can be improved.

[1-3] Cooling Unit Cooling unit 130 is a member for radiating heat from power semiconductor element 120 . Examples of such a cooling unit 130 include a vapor chamber, radiating fins, a Peltier device, an air-cooling unit, a water-cooling unit, and the like.

The cooling unit 130 is fixed on the other surface 110b of the substrate 110 by screws 131, for example.
As a result, the adhesion between the substrate 110 and the cooling unit 130 can be improved, and the cooling efficiency of the cooling unit 130 can be reliably improved. In addition, by fixing with screws 131 (bolting), it is possible to more preferably adjust the surface pressure when the thermal conductor 1 is brought into close contact.

In particular, by soldering the power semiconductor element 120 to the substrate 110 and fixing the cooling unit 130 on the substrate 110 by screwing, the above effects can be obtained and the power semiconductor element 120 can be used as an electronic device. Unfavorable thermal history during the manufacturing process of the circuit board 100 can be effectively prevented, and the reliability of the electronic circuit board 100 can be improved. Moreover, the productivity of the electronic circuit board 100 can be further improved.

[1-4] Heat Conductor FIG. 2 is a perspective view schematically showing an example of a heat conductor. FIG. 3 is a cross-sectional view schematically showing an enlarged portion of the laminated heat-conducting portion and the joint portion. FIG. 4 is a plan view schematically showing an example of a heat conducting portion that constitutes a heat conductor. FIG. 5 is a schematic partially exploded perspective view showing a plurality of laminated heat-conducting parts exploded. FIG. 6 is a conceptual diagram of an example of a cured product of a curable resin material forming a joint. 3, illustration of the resin fibers 22 is omitted.

The heat conductor 1 is used by being inserted into the through holes 111 in the electronic circuit board 100 having the substrate 110 in which the through holes 111 are formed. are in contact with different members on both sides.

In the configuration shown in FIG. 1, for example, the thermal conductor 1 is in contact with the power semiconductor element 120 on one side (ie, one side 110a of the substrate 110) and on the other side (ie, the other side of the substrate 110). (surface 110b side) is in contact with the cooling unit 130 .

As will be described in detail later, the thermal conductor 1 has excellent thermal conductivity in a predetermined direction, that is, thermal conductivity in terms of the thickness of the substrate 110, and is arranged on both surface sides of the substrate 110. It is used so as to be in contact with different members.

The heat conductor 1 has flexibility. As a result, it is possible to ensure sufficient adhesion to members in contact with the heat conductor 1, such as high temperature members and heat dissipating members, and it is possible to keep the interfacial thermal resistance low and substantially increase the thermal conductivity. .

The compressibility of the thermal conductor 1 when the thermal conductor 1 is compressed with a stress of 0.25 MPa at 20° C. in the direction corresponding to the direction of insertion into the through hole 111 is 4.0% or more and 10.0%. It is preferably less than or equal to, more preferably 5.0% or more and 8.0% or less.
As a result, the above-described effects of the present invention are exhibited more remarkably.

The compressibility of the thermal conductor 1 when the thermal conductor 1 is compressed with a stress of 0.50 MPa at 20° C. in the direction corresponding to the direction of insertion into the through hole 111 is 7.0% or more and 20.0%. or less, more preferably 9.0% or more and 15.0% or less.
As a result, the above-described effects of the present invention are exhibited more remarkably.

The heat conductor 1 may be flexible as a whole and have heat conductivity as a whole, but is preferably made of a material containing a resin.
As a result, the adhesion between the member in contact with the heat conductor 1 and the heat conductor 1 can be excellent, and the substantial thermal conductivity between the member and the heat conductor 1 can be improved. can be excellent.

The heat conductor 1 may be flexible as a whole, but the heat conductor 1 shown in FIG. and a joint portion 20 for joining 10 . In other words, the thermal conductor 1 shown in FIG. 2 is a composite laminate having a plurality of thermally conductive portions 10 and joint portions 20 . At least part of the surfaces of the heat conducting part 10 and the joint part 20 can contact a member to which the heat conducting body 1 is applied in a state where the heat conducting body 1 is inserted into the through hole 111 of the substrate 110. arranged in a form.
As a result, the adhesion between the member in contact with the heat conductor 1 and the heat conductor 1 can be excellent, and the substantial thermal conductivity between the member and the heat conductor 1 can be improved. can be excellent.

In the following description, the heat conductor 1 includes a plurality of heat conductive portions 10 and a joint portion 20 that is made of a material containing a flexible resin material 21 and that joins the heat conductive portions 10. Mainly explained.

The heat conductor 1 only needs to have at least one joint 20, but in the example shown in FIG. A heat conducting part 10 is arranged at both ends.

Although it will be specifically described later, such a heat conductor 1 is, for example, a heat conductive part 10 in which a joint forming composition 20 ′ used for forming the joint 20 is applied to at least one surface. By winding a heat conductive portion forming sheet (heat conductive portion forming member) 10′ used for formation on the peripheral surface of the winding roll R2, the heat conductive portions 10 and the joint portions 20 are alternately laminated. Therefore, it can be manufactured suitably.

Here, in the present specification, the stacking direction of the heat conductive portion 10 and the joint portion 20 in the heat conductor 1 is defined as the stacking direction of the heat conductor 1, and the in-plane direction of the heat conductive portion forming sheet 10 ′ is defined as the in-plane direction of the heat conducting portion 10 . For example, in the configuration shown in FIG. 2 , the lateral direction is the stacking direction of the heat conductors 1 , and the vertical depth direction is the in-plane direction of the heat conducting section 10 . 7 and 8, which will be described later, the lateral depth direction is the in-plane direction of the heat-conducting portion forming sheet 10' and the in-plane direction of the heat-conducting portion 10. As shown in FIG.

Further, in this specification, the extending direction of the heat conducting portion 10 within the plane of the upper surface of the heat conductor 1 is defined as the extending direction of the heat conducting portion 10 . For example, in the configuration shown in FIG. 2 , the in-plane depth direction of the upper surface of the heat conductor 1 is the extending direction of the heat conducting portion 10 .

The thermal conductor 1 preferably has anisotropic thermal conductivity.
Thereby, the heat conductor 1 can more efficiently transmit heat in a predetermined direction. In addition, it is possible to prevent unwanted heat conduction, and it is possible to more effectively prevent adverse effects of heat on the substrate 110 (particularly, the laminated substrate) and components provided on the substrate 110.

In the heat conductor 1 having the configuration shown in FIG. higher than
Thereby, the heat conductor 1 can transmit heat more efficiently in the in-plane direction of the heat conducting portion 10 than in the lamination direction of the heat conducting portion 10 and the joint portion 20 .

The thermal conductor 1 preferably has a higher thermal conductivity in the thickness direction of the substrate 110 than in a predetermined in-plane direction of the substrate 110 .

As a result, the heat conductor 1 can more efficiently transmit heat in the thickness direction of the substrate 110, and the above-described effects of the present invention are exhibited more remarkably.

For example, when the heat conductor 1 is arranged in the through hole 111 of the substrate 110, the in-plane direction of the heat conduction portion 10 is the thickness direction of the substrate 110, and the heat conduction portion 10 is bonded to the above conditions. This can be satisfied by making the lamination direction of the portion 20 the in-plane direction of the substrate 110 .

The thermal conductor 1 also has anisotropic thermal conductivity on the upper surface, in other words, in the plane of the surface exposed on the surface of the substrate 110 . That is, the heat conductor 1 has a lower thermal conductivity in the stacking direction of the heat conducting portion 10 and the joint portion 20 than in the extending direction of the heat conducting portion 10 in the plane of the upper surface.

As will be described later, the heat conductor 1 is defined, for example, in the plane of the substrate 110 by defining the extending direction of the heat conducting portion 10 and the joint portion 20 and the stacking direction of the heat conducting portion 10 and the joint portion 20 as follows: Anisotropy can be imparted to the thermal conductivity in the plane of the substrate 110 through the thermal conductor 1 by controlling the arrangement with respect to the X-axis direction and the Y-axis direction in the plane of the substrate 110. can.

The shape of the heat conductor 1 is not particularly limited, but is preferably set appropriately according to the shape of the through holes 111 formed in the substrate 110 .
As a result, the effects of the present invention described above are exhibited more remarkably.

Examples of the shape of the heat conductor 1 when viewed from above and the cross-sectional shape of the heat conductor 1 include circular, elliptical, polygonal, and combinations thereof. Moreover, the longitudinal cross-sectional shape of the heat conductor 1 may have a constant width in the thickness direction of the substrate 110, or may have a portion whose width changes depending on the thickness of the substrate 110. may be

When the shape of the heat conductor 1 when viewed from above and the cross-sectional shape of the heat conductor 1 are polygonal, for example, square, the maximum length of one side of the square is 5 mm or more and 15 mm or less. It is preferably 7 mm or more and 10 mm or less.
As a result, a sufficient contact area between the heat conductor 1 and a member that contacts the heat conductor 1 can be ensured, and the above-described effects can be exhibited more reliably and more remarkably.

Specifically, for example, it is preferable that the shape of the heat conductor 1 in a plan view is a square shape larger than 5 mm×5 mm square.
Thereby, the effect mentioned above can be exhibited more notably.

In addition, the size of the heat conductor 1 may be constant in the thickness direction of the substrate 110, or may not be constant. When the thermal conductor 1 has portions with different sizes in the thickness direction of the substrate 110, the value of one side at the portion where the length of one side of the thermal conductor 1 is the maximum is a value within the above range. Preferably.

For example, in the illustrated configuration, the shape and size of the heat conductor 1 are constant in the thickness direction of the substrate 110 . Specifically, the heat conductor 1 has a quadrangular prism shape. As a result, the thermal conductivity in the thickness direction of the substrate 110 due to the thermal conductor 1 inserted into the through hole 111 can be kept constant, and the effects of the present invention can be made more remarkable. In addition, the process of cutting the heat conductor 1, inserting the heat conductor 1 into the through hole 111, and the like can be suitably performed, which is advantageous in terms of manufacturing.

Even if the shape of the through-hole 111 is complicated, the heat conductor 1 can be cut according to the shape of the through-hole 111. Therefore, compared with the case of using a copper inlay, for example, it is easier to cut the heat conductor 1. can respond.

The length of the heat conductor 1 in the natural state in the thickness direction of the substrate 110, that is, the length indicated by T2 in FIG. 0 mm or less is more preferable.
As a result, the member in contact with the heat conductor 1 and the heat conductor 1 can be more preferably brought into close contact with each other, and substantially excellent thermal conductivity can be obtained. Therefore, for example, when the member in contact with the heat conductor 1 is a heating element, the heat dissipation can be made more excellent.

The following description will focus on the case where the heat conductor 1 has a quadrangular prism shape.
Note that although the drawings referred to in this specification clearly show the interface between the heat conducting portion 10 and the joint portion 20, for example, part of the heat conducting portion 10 penetrates into the joint portion 20. Therefore, the interface between the heat conducting portion 10 and the joint portion 20 may be unclear.

[1-4-1] Heat conduction part The heat conduction part 10, which has a plurality of parts, is a part that mainly contributes to the thermal conductivity of the entire heat conductor 1, especially the thermal conductivity in the in-plane direction of the heat conduction part 10. be.

At least some of the plurality of heat conducting portions 10 are provided continuously inside the heat conductor 1, particularly inside the heat conductor 1 in the thickness direction of the substrate 110, and are different from each other in the heat conductor 1. It is preferable that the heat conductor 1 is exposed on two surfaces, particularly two different surfaces that contact another member, in other words, on both surfaces of the through-hole 111 in the depth direction.
Thereby, substantial thermal conductivity in the thickness direction of the substrate 110 can be made more excellent.

In particular, the thermal conductor 1 of the illustrated configuration has at least one set of parallel surfaces, and at least some of the plurality of thermally conductive portions 10 are provided continuously inside the thermal conductor 1. and through heat conducting portions exposed on the two surfaces.
As a result, the member in contact with the heat conductor 1 and the heat conductor 1 can be brought into close contact with each other, and substantial heat transfer between the two parallel surfaces, in other words, between both surfaces of the substrate 110 can be achieved. Better conductivity can be achieved.
In this specification, "parallel" does not mean strictly "parallel" in a mathematical sense, but allows for some deviation.

The heat conducting portion 10 is not particularly limited as long as it has thermal conductivity, and examples of the material forming the heat conducting portion 10 include ceramic materials such as aluminum nitride, boron nitride, silicon nitride, silicon carbide, and alumina. , graphite, carbon materials such as carbon fiber, and metal materials such as copper and aluminum. .
Thereby, the manufacturing cost of the heat conductor 1 can be suppressed while substantially improving the thermal conductivity between the member in contact with the heat conductor 1 and the heat conductor 1 .

[1-4-1-1] Carbon material In particular, when the heat conducting portion 10 is formed of the heat conducting portion forming sheet 10' containing a carbon material such as graphite or carbon fiber, the effect described above In addition to this, the following effects can be obtained. That is, the suppleness and flexibility of the heat conductor 1 can be improved, for example, the restoring force when the heat conductor 1 is bent, the cushioning property due to the internal voids, and the heat conductor It is possible to improve the contact property by moderate deformation when contacting with a member that contacts 1, and the like. In particular, such an effect is exhibited more remarkably when graphite is used as the carbon material.

It is preferable to use flake graphite as the graphite that constitutes the heat conducting portion 10 .
By using flaky graphite, the flaky graphite can be suitably oriented in the in-plane direction of the heat-conducting portion 10 by a method described later, and the thermal conductivity in the in-plane direction of the heat-conducting portion 10 can be improved. It can be made particularly good. In addition, by using flake graphite, a portion of the heat conduction portion 10 other than the hole portion 11 described later, particularly the central portion in the thickness direction of the heat conduction portion 10 which is the normal direction of the in-plane direction of the heat conduction portion 10 A gap 12, which will be described later, can be preferably provided in the vicinity, and effects as described later can be obtained.

[1-4-1-2] Ceramic material In addition, when the heat conduction part 10 is made of a ceramic material, a member in contact with the heat conductor 1 and a substantial heat between the heat conductor 1 It is possible to further reduce the dust generation of the heat conductor 1 while making the conductivity more excellent, and for example, it is possible to more effectively prevent the occurrence of problems such as electrical shorts in electronic circuits. . In particular, nitride ceramics such as aluminum nitride and oxide ceramics such as alumina are highly insulating materials themselves. Even if it falls off, the above problems can be effectively prevented.

[1-4-1-3] Metal material In addition to the effects described above, if the heat conduction part 10 is formed of a heat conduction part forming sheet 10' made of a metal material, the following You can get the effect like That is, the dust generation property of the heat conductor 1 can be further reduced due to the strength of the bonding force inside the metal material. In addition, even when a relatively large load is applied to the heat conductor 1, irreversible deformation of the heat conductor 1, such as collapse of the heat conductor 1 due to buckling, etc., is more effectively prevented. .

Various single metals, alloys, and the like can be cited as the metal material that constitutes the heat conducting portion 10, and one or more selected from these can be used in combination. More specifically, the metal material that constitutes the heat conduction part 10 includes, for example, one or more selected from the group consisting of Al, Cu, Ag, Au, Mg, and Zn. However, it preferably contains Al.
Thereby, the heat conductivity of the heat conducting portion 10 can be further improved.
Examples of alloys containing metal elements constituting the group include duralumin, which is an aluminum alloy containing Al, Cu and Mg.

Preferably, the heat-conducting portion 10 is substantially composed of a single component.
Thereby, the heat conductivity of the heat conducting portion 10 can be further improved. In general, it is also advantageous in suppressing the manufacturing cost of the heat conductor 1 .
The expression "substantially composed of a single component" means that the proportion of the main component in the target portion is 95% by weight or more. The proportion of the main component is preferably 97% by weight or more, more preferably 99% by weight or more.

However, when gas such as air is contained in the heat conducting portion 10, the content of the gas is ignored. Moreover, when the heat conducting part 10 is made of a metal material, a metal oxide film, such as a passivation film, may be formed on the surface of the heat conducting part 10 . Even when such an oxide film is formed, it shall be treated as "substantially composed of a single component". The same applies to the heat conductive portion forming sheet 10', which will be described in detail later.

The in-plane thermal conductivity of the heat conducting portion 10 at 20° C. is preferably 7 W/(m K) or more and 2500 W/(m K) or less, and is preferably 20 W/(m K) or more and 1800 W/( m·K) or less is more preferable.
The value of thermal conductivity can be obtained by measurement by a non-stationary hot wire method based on the laser flash method.

The thickness of the heat conducting portion ₁₀ in the stacking direction indicated by t10 in FIG. 2 is preferably 5 μm or more and 500 μm or less, more preferably 20 μm or more and 150 μm or less.
As a result, while the ratio of the heat conductive portion 10 in the heat conductor 1 is sufficiently high, the flexibility of the heat conductor 1 as a whole can be easily improved, and the above effects can be more reliably achieved. It can be exhibited remarkably.
However, here, the thickness of the heat conducting portion 10 refers to the thickness of the portion where the hole portion 11 described below is not provided.

As shown in FIG. 2, each heat conducting portion 10 constituting the heat conductor 1 may be provided with a concave portion in the thickness direction thereof.
Thereby, the bonding strength between the heat conducting portion 10 and the bonding portion 20 can be improved.

In particular, in each heat-conducting portion 10 shown in FIG. 3 , the recess is a hole portion 11 penetrating through the heat-conducting portion 10 in the thickness direction.
Thereby, the effect mentioned above is exhibited more notably.

In the following description, the case where the recess is a hole will be mainly described.
The number of holes (concave portions) 11 provided in each heat conducting portion 10 may be only one, but may be plural, depending on the size of the heat conducting portion 10 in the in-plane direction. is preferred.
As a result, the effects described above are exhibited more remarkably.

When a plurality of holes 11 are provided in a single heat conducting portion 10, the distance between adjacent holes 11 in the in-plane direction of the heat conducting portion 10 is preferably 300 μm or more and 1000 μm or less. , 400 μm or more and 800 μm or less.
Thereby, the above effect can be made more remarkable.
Here, in this specification, the “interval between holes 11 ” means the distance between the centers of adjacent holes 11 .

In the configuration shown in FIG. 4, the plurality of holes 11 provided with the single heat conducting portion 10 are arranged in a zigzag pattern. The arrangement pattern of the holes 11 is not limited to this, and may be any pattern, for example, may be randomly provided.

A resin material 21 has penetrated into at least a portion of the hole 11 . In other words, the cured product of the curable resin material penetrates through the recess into the interior of the heat conducting portion 10 provided with the recess.
As a result, in particular, the resin material 21 penetrates into the hole 11 provided in the heat conducting portion 10, so that the joint between the heat conducting portion 10 and the joint portion 20 can be made stronger, and the heat can be conducted. The shape adaptability to the surface shape of members in contact with the body 1, such as heat generating members and heat radiating members, and the durability of the heat conductor 1 can be improved.

As shown in FIG. 5 , it is preferable that non-overlapping holes 11 exist in a plurality of heat conducting portions 10 when the heat conducting portions 10 are observed from the stacking direction with the bonding portion 20 .

If there are overlapping holes 11 in a plurality of heat conducting parts 10, the resin material 21 of the joint part 20 entering the overlapping hole parts 11 is skewered through the plurality of heat conducting parts 10.例文帳に追加In such a case, the resin material 21 may slip through the hole 11 and the bonding between the heat conducting portions 10 may become insufficient.

On the other hand, when observing the heat conducting portion 10 from the lamination direction with the joining portion 20, there are non-overlapping hole portions 11 in the plurality of heat conducting portions 10, so that the holes 11 are penetrated. The resin material 21 is prevented from slipping through the joint portion 20, and the joint between the heat conducting portions 10 can be made stronger.

In addition, in FIG. 5, only the portion of the heat conducting portion 10 is extracted and shown, and the joint portion 20 is omitted.
The shape of the hole 11 is not particularly limited. , ellipses, polygons, and the like. Further, the longitudinal cross-sectional shape of the heat conducting portion 10 may have a constant width in the depth direction of the hole portion 11, or may have a width that changes in the depth direction of the hole portion 11. may have

When the shape of the hole 11 when the heat conducting part 10 is viewed from above and the cross-sectional shape of the hole 11 of the heat conducting part 10 are circular, the diameter of the hole 11 is 30 μm or more and 500 μm or less. and more preferably 50 μm or more and 200 μm or less.
Thereby, the above effect can be made more remarkable.

The size (diameter) of the hole portion 11 may be constant in the thickness direction of the heat conducting portion 10, or may not be constant. When the heat conducting portion 10 has a portion with a different size (diameter) of the hole 11 in the thickness direction, the value of the diameter at the portion where the diameter of the hole 11 is the largest is within the above range. is preferred.

The proportion of the heat conductive portion 10 in the heat conductor 1 is preferably 15% by volume or more and 80% by volume or less, more preferably 20% by volume or more and 70% by volume or less.
Thereby, the effect mentioned above is exhibited more notably.

The proportion of the heat conducting part 10 in the heat conducting body 1 (however, the body part excluding the void part 2) is 30% or more and 90% or less in terms of the area ratio of the cross section in the lamination direction of the heat conducting body 1. is preferred, and 40% or more and 82% or less is more preferred.
Thereby, the effect mentioned above is exhibited more notably.

[1-4-2] Joint The joint 20 is arranged between two adjacent heat conducting portions 10 to join the heat conducting portions 10 to each other, and contains a flexible resin material 21. consists of The resin material 21 is a cured product of a curable resin material 21', which will be described later.

By including the resin material 21 having flexibility in the joint portion 20, the heat conductor 1 has excellent shape adaptability to the surface shape of a member in contact with the heat conductor 1, such as a heat generating member or a heat radiating member. become a thing.
Moreover, since the joint portion 20 includes the resin material 21 having flexibility, it is possible to suitably prevent the heat conductor 1 from being damaged when the heat conductor 1 is deformed.

[1-4-2-1] Resin material The resin material 21 forming the joint 20 is not particularly limited as long as it has flexibility. Examples include flexible epoxy resin, rubber resin, and urethane resin. , silicone resins, fluorine resins, acrylic resins, thermoplastic elastomers, etc., and the resin material 21 includes, as shown in FIG. A polyrotaxane 50 having a first polymer 52 that clathrates 51 in a skewered manner and blocking groups 53 provided near both ends of the first polymer 52, and a second polymer 60, through the cyclic molecule 51 Therefore, it is preferable that the polyrotaxane 50 and the second polymer 60 are bonded.

As a result, the bonding strength and the like between the heat conducting portion 10 and the joint portion 20 in the heat conductor 1 can be improved, and the durability of the heat conductor 1 can be improved. Moreover, the flexibility, heat resistance, etc. of the heat conductor 1 can be made particularly excellent.

In particular, when stress in the direction of the arrow is applied to the resin material 21 in the state shown in FIG. 6(A), the resin material 21 can take the form shown in FIG. 6(B). That is, in the resin material 21, since the cyclic molecules 51 can move along the first polymer 52, that is, the first polymer 52 can move inside the cyclic molecules 51, the deformation stress can be applied to the resin material 21. 21 can be efficiently absorbed. Therefore, even if a large external force such as a torsional deformation force is applied, breakage of the joint 20 or breakage of the joint between the heat conducting portions 10 can be effectively prevented.

The resin material 21 including the polyrotaxane 50 and the second polymer 60 will be described in detail below.
The cyclic molecule 51 constituting the polyrotaxane 50 may be one that can move along the first polymer 52, but is preferably an optionally substituted cyclodextrin molecule, and the cyclodextrin molecule is α- Particularly preferred are those selected from the group consisting of cyclodextrin, β-cyclodextrin and γ-cyclodextrin, and derivatives thereof.

At least part of the cyclic molecules 51 in the polyrotaxane 50 are bonded to at least part of the second polymer 60 as described above.
Examples of functional groups possessed by the cyclic molecule 51 (functional groups that bind to the second polymer 60) include —OH groups, —NH ₂ groups, —COOH groups, epoxy groups, vinyl groups, thiol groups, and photocrosslinking groups. etc. Examples of the photocrosslinking group include cinnamic acid, coumarin, chalcone, anthracene, styrylpyridine, styrylpyridinium salt, styrylquinolium salt, and the like.

Assuming that the maximum amount of the cyclic molecule 51 that is included when the cyclic molecule 51 is skewered by the first polymer 52 is 1, the amount of the cyclic molecule 51 that is skewered by the first polymer 52 is The amount of the cyclic molecules 51 present is preferably 0.001 or more and 0.6 or less, and more preferably 0.05 or more and 0.4 or less. Two or more different cyclic molecules 51 may be used.

Examples of the first polymer 52 constituting the polyrotaxane 50 include polyvinyl alcohol, polyvinylpyrrolidone, poly(meth)acrylic acid, cellulose-based resins such as carboxymethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose, polyacrylamide, polyethylene oxide, and polyethylene. Glycol, polypropylene glycol, polyvinyl acetal resin, polyvinyl methyl ether, polyamine, polyethyleneimine, casein, gelatin, starch, etc. and/or their copolymers, polyethylene, polypropylene, and copolymer resins with other olefinic monomers Polyolefin resins such as polyester resins, polyvinyl chloride resins, polystyrene resins such as polystyrene and acrylonitrile-styrene copolymer resins, polymethyl methacrylate and (meth)acrylic acid ester copolymers, acrylonitrile-methyl acrylate copolymer resins, etc. Acrylic resins, polycarbonate resins, polyurethane resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl butyral resins, etc.; and derivatives or modified products thereof, polyisobutylene, polytetrahydrofuran, polyaniline, acrylonitrile-butadiene-styrene copolymer Polyamides such as nylon, polyimides, polyisoprene, polydienes such as polybutadiene, polysiloxanes such as polydimethylsiloxane, polysulfones, polyimines, polyacetic anhydrides, polyureas, polysulfides, polyphosphazenes, Examples include polyketones, polyphenylenes, polyhaloolefins, and derivatives thereof, with polyethylene glycol being particularly preferred.

The weight average molecular weight of the first polymer 52 is preferably 10,000 or more, more preferably 35,000 or more. Two or more different first polymers 52 may be used.

As a combination of the cyclic molecule 51 and the first polymer 52, it is preferable that the cyclic molecule 51 is α-cyclodextrin, which may be substituted, and the first polymer 52 is polyethylene glycol.

The blocking group 53 constituting the polyrotaxane 50 is not particularly limited as long as it is a group having a function of preventing the cyclic molecule 51 from detaching from the first polymer 52. Examples include dinitrophenyl groups, cyclodextrins, adamantane groups, trityl groups, fluoresceins, pyrenes, substituted benzenes (substituents include alkyl, alkyloxy, hydroxy, halogen, cyano, sulfonyl, carboxyl, amino, phenyl, etc. One substituent or a plurality thereof may exist.), optionally substituted polynuclear aromatics, steroids, and the like.

Substituents constituting substituted benzenes and substituted polynuclear aromatics include alkyl, alkyloxy, hydroxy, halogen, cyano, sulfonyl, carboxyl, amino, phenyl and the like. One or more substituents may be present. Two or more different blocking groups 53 may be used.

At least part of the polyrotaxane 50 in the resin material 21 is bound to the second polymer 60 via the cyclic molecules 51, but is not bound to the second polymer 60 in the resin material 21. The polyrotaxane 50 may be contained, or the polyrotaxanes 50 may be bonded to each other.

The second polymer 60 is bound to the polyrotaxane 50 via the cyclic molecule 51 . Examples of functional groups that bind to the cyclic molecules 51 of the second polymer 60 include —OH groups, —NH ₂ groups, —COOH groups, epoxy groups, vinyl groups, thiol groups, and photocrosslinking groups. Examples of the photocrosslinking group include cinnamic acid, coumarin, chalcone, anthracene, styrylpyridine, styrylpyridinium salt, styrylquinolium salt, and the like.

Examples of the second polymer 60 include polyvinyl alcohol, polyvinylpyrrolidone, poly(meth)acrylic acid, cellulose-based resins such as carboxymethylcellulose, hydroxyethylcellulose, and hydroxypropylcellulose, polyacrylamide, polyethylene oxide, polyethylene glycol, polypropylene glycol, Polyolefin resins such as polyvinyl acetal resin, polyvinyl methyl ether, polyamine, polyethyleneimine, casein, gelatin, starch, etc. and/or their copolymers, polyethylene, polypropylene, and copolymer resins with other olefin monomers , polyester resins, polyvinyl chloride resins, polystyrene resins such as polystyrene and acrylonitrile-styrene copolymer resins, acrylic resins such as polymethyl methacrylate, (meth)acrylic acid ester copolymers, acrylonitrile-methyl acrylate copolymer resins, polycarbonate resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, etc.; , polyimides, polyisoprene, polydienes such as polybutadiene, polysiloxanes such as polydimethylsiloxane, polysulfones, polyimines, polyacetic anhydrides, polyureas, polysulfides, polyphosphazenes, polyketones, polyphenylenes , and polyhaloolefins having a skeleton of various resins and having the above-described functional groups.

Also, the second polymer 60 and the cyclic molecule 51 may be chemically bonded with a cross-linking agent.
The molecular weight of the cross-linking agent is preferably less than 2000, more preferably less than 400.

Examples of cross-linking agents include cyanuric chloride, trimesoyl chloride, terephthaloyl chloride, epichlorohydrin, dibromobenzene, glutaraldehyde, phenylene diisocyanate, trilein diisocyanate, divinyl sulfone, 1,1′-carbonyldiimidazole, Alkoxysilanes and the like can be mentioned. Two or more different cross-linking agents may be used.

Also, the second polymer 60 may be a homopolymer or a copolymer. At least part of the second polymer 60 in the resin material 21 is bonded to the polyrotaxane 50 via the cyclic molecule 51, but the second polymer 60 in the resin material 21 is not bonded to the polyrotaxane 50. may be included, or the second polymers 60 may be bonded to each other. Two or more different second polymers 60 may be used.
The weight ratio of the content of the polyrotaxane 50 to the content of the second polymer 60 in the resin material 21 is preferably 1/1000 or more.

The content of the resin material 21 in the joint portion 20 is preferably 5% by volume or more and 90% by volume or less, more preferably 25% by volume or more and 75% by volume or less.

As a result, the bonding strength of the heat conducting portion 10 by the bonding portion 20 is improved, and when the bonding portion 20 contains the resin fiber 22, the content of the resin fiber 22 in the bonding portion 20 is sufficiently secured. The effect of containing the resin fibers 22 can be sufficiently exhibited.

[1-4-2-2] Resin Fiber The joint portion 20 may include resin fibers 22 together with the resin material 21 as described above.

As a result, even when the heat conductor 1 is used in a state of being pressed for a long time, it is possible to effectively prevent the heat conductor 1 from being sag-deformed. It is possible to effectively prevent the occurrence of the problem that the adhesion between the thermal conductor 1 and the member in contact with it decreases and the thermal resistance increases due to the decrease in pressure over time.

The thickness of the resin fibers 22 contained in the joint portion 20 is preferably 1.0 μm or more and 30 μm or less, more preferably 2.0 μm or more and 25 μm or less, and preferably 3.0 μm or more and 20 μm or less. More preferably, it is most preferably 4.0 μm or more and 15 μm or less.
Thereby, the effect mentioned above is exhibited more notably.

The resin fibers 22 may be mainly composed of a resin material. Examples of the resin material constituting the resin fibers 22 include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides, and the like. Examples thereof include ethylene vinyl acetate resin, polyvinyl alcohol, etc., but the resin fibers 22 are preferably made of polyester, and more preferably made of polyethylene terephthalate.

As a result, the strength of the resin fiber 22 itself can be made more excellent, and the effect of including the resin fiber 22 in the joint portion 20 as described above can be more effectively exhibited. The adhesion between the fibers 22 and the resin material 21 can be improved, and the durability and reliability of the heat conductor 1 can be improved.

At least one resin fiber 22 should be included in the joint portion 20, but preferably a plurality of resin fibers 22 are included.
Thereby, the effect mentioned above is exhibited more notably.

Further, each resin fiber 22 may be contained in the joining portion 20 in an independent state, or may be contained in a state in which a plurality of resin fibers 22 are entangled. More specifically, the resin fibers 22 may be made of, for example, woven fabric or non-woven fabric.

In particular, since the resin fibers 22 are included in the joint portion 20 as a non-woven fabric, the resin fibers 22 can be more uniformly distributed in the joint portion 20, thereby effectively suppressing unwanted variations in composition. can be used, and the effects described above can be exhibited more remarkably.

The content of the resin fibers 22 in the joint portion 20 is preferably 2% by volume or more and 70% by volume or less, more preferably 4% by volume or more and 50% by volume or less, and 6% by volume or more and 30% by volume or less. is more preferable.

As a result, the effect of including the resin fiber 22 described above can be exhibited more remarkably, and the content of the resin material 21 in the joint portion 20 can be sufficiently ensured, and heat conduction by the joint portion 20 can be achieved. The bonding strength of the portion 10 can be made sufficiently excellent.

When the content rate of the resin material 21 in the joint portion 20 is X1 [% by volume] and the content rate of the resin fiber 22 in the joint portion 20 is X2 [% by volume], 0.04≦X2/X1≦10.0. , more preferably 0.07≤X2/X1≤5.0, and even more preferably 0.10≤X2/X1≤3.0.
Thereby, the effect mentioned above is exhibited more notably.

[1-4-2-3] Metal Particles In addition to the resin material 21 and the resin fibers 22, the joint 20 may contain metal particles (not shown).
As described above, the portion that mainly contributes to the thermal conductivity in the in-plane direction of the heat conducting portion 10 is the heat conducting portion 10 , but the metal particles are generally more dense than the resin material 21 forming the joint portion 20 . Since it has high thermal conductivity, the inclusion of metal particles in the joint portion 20 can improve the thermal conductivity of the joint portion 20, and the thermal conductivity of the thermal conductor 1 as a whole can be improved. Further improvement can be achieved.

In particular, when adjacent heat conducting portions 10 are connected by one or more metal particles contained in the joint portion 20, the metal particles form a “thermal path” that thermally connects the heat conducting portions 10. , the thermal conductivity of the thermal conductor 1 as a whole can be further improved.

Furthermore, by including metal particles made of a metal material having electromagnetic wave shielding properties, the heat conductor 1 can also be provided with an electromagnetic wave shielding function. In particular, for example, a shielding function against high-frequency electromagnetic waves used in fifth-generation mobile communications can be suitably imparted.

The metal particles preferably contain one or more selected from the group consisting of Fe, Ag, Pt, Cu, Sn, Al and Ni, more preferably iron particles.

Although the average particle diameter of the metal particles is not particularly limited, it is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 3.0 μm or less.
In the present specification, the average particle size refers to the particle size when the cumulative 50% from the small diameter side in the weight-based particle size distribution measured with a laser diffraction particle size distribution analyzer.

The content of the metal particles in the joint portion 20 is preferably 1% by volume or more and 50% by volume or less, and more preferably 10% by volume or more and 30% by volume or less.

[1-4-2-4] Ceramic Particles The joint 20 may contain ceramic particles (not shown) in addition to the above materials.
As a result, the texture of the joint 20 can be stabilized and made uniform, and the ratio and size of voids in the joint 20 can also be stabilized. As a result, it is possible to more effectively prevent undesired variations in the characteristics of each part of the heat conductor 1 .

Ceramic particles can be made of various ceramics, including nitride ceramics such as aluminum nitride, boron nitride and silicon nitride, carbide ceramics such as silicon carbide, and oxide ceramics such as alumina. When used, the thermal conductivity of the heat conductor 1 as a whole can be further improved. In particular, when adjacent heat conducting portions 10 are connected by one or more ceramic particles contained in the joint portion 20, the ceramic particles become a “thermal path” that thermally connects between the heat conducting portions 10. , the thermal conductivity of the thermal conductor 1 as a whole can be further improved.

When the joint 20 contains the metal particles described above in addition to the ceramic particles, the heat path may be formed of the ceramic particles and the metal particles.
In addition, the ceramic particles may be composed of silica. As a result, the production cost of the heat conductor 1 can be suppressed, and effects such as stabilization and uniformity of the structure of the joint portion 20 described above can be obtained.

Although the average particle diameter of the ceramic particles is not particularly limited, it is preferably 5 μm or more and 200 μm or less, more preferably 20 μm or more and 70 μm or less.

The content of the ceramic particles in the joint portion 20 is preferably 1% by volume or more and 50% by volume or less, more preferably 10% by volume or more and 30% by volume or less.
As a result, the effect of including the resin material 21 and the effect of including the ceramic particles can be exhibited in a well-balanced manner.

[1-4-2-5] Spacer The joint 20 may contain a spacer.
When the joint portion 20 contains spacers, it is possible to suitably suppress unwanted variations in the thickness of the joint portion 20 .

The shape of the spacer may be, for example, a spheroidal shape, a cylindrical shape, a prismatic shape, a needle shape, etc., preferably spherical, and more preferably spherical.
Thereby, undesired variations in the thickness of the joint portion 20 can be more suitably suppressed. In addition, the space 2 can be more preferably formed between the cured product of the curable resin material 21 ′ that constitutes the joint 20 and the spacer.

When the spacer is spherical, particularly spherical, the average particle diameter of the spacer is not particularly limited, but is preferably 0.1 μm or more and 100 μm or less, more preferably 1.0 μm or more and 50 μm or less. preferable.

The spacer may be made of any material, for example, metal material, ceramic material, glass, etc., but is preferably made of resin material. .

Examples of the resin material constituting the spacer include polyester resins such as polyethylene terephthalate, acrylic resins, polyolefin resins such as polyvinyl chloride, polystyrene, polyethylene, and polypropylene, phenolic resins (including bakelite), and fluorine resins. etc., and one or more selected from these can be used in combination.

When the joint 20 contains a spacer, the content of the spacer in the joint 20 is preferably 0.1% by volume or more and 20% by volume or less, and is 0.5% by volume or more and 10% by volume or less. is more preferred.

[1-4-2-6] Other Components The joint 20 may contain components other than the components described above.
Examples of such components include plasticizers, colorants, antioxidants, ultraviolet absorbers, light stabilizers, softeners, modifiers, rust inhibitors, fillers, electromagnetic wave absorbers such as ferrite, and surface lubricants. agents, corrosion inhibitors, heat stabilizers, lubricants, primers, antistatic agents, polymerization inhibitors, cross-linking agents, catalysts, leveling agents, thickeners, dispersants, anti-aging agents, flame retardants, hydrolysis inhibitors, etc. mentioned.

However, the content of these components in the joint portion 20 is preferably 5% by weight or less, more preferably 1% by weight or less.

In FIG. 2, the thickness of the joint portion ₂₀ in the stacking direction of the heat conducting portion 10 and the joint portion 20 indicated by t20 is preferably 0.1 μm or more and 1000 μm or less, and is 5.0 μm or more and 100 μm or less. is more preferable.
Thereby, the effect mentioned above is exhibited more notably.
However, here, the thickness of the joint portion 20 refers to the thickness of a portion of the contacting heat conducting portion 10 where the hole portion 11 is not provided.

The proportion of the joint 20 in the heat conductor 1 is preferably 15% by volume or more and 70% by volume or less, more preferably 16% by volume or more and 60% by volume or less, and 18% by volume or more and 50% by volume. More preferably:
Thereby, the effect mentioned above is exhibited more notably.

The proportion of the joint portion 20 in the heat conductor 1 (the actual portion excluding the gap portion 2) is 10% or more and 70% or less in terms of the area ratio of the cross section in the lamination direction of the heat conductor 1. It is preferably 15% or more and 60% or less, and even more preferably 18% or more and 50% or less.
Thereby, the effect mentioned above is exhibited more notably.

[1-4-3] Gap portion In the illustrated configuration, the heat conductor 1 has, in addition to the heat conduction portion 10 and the joint portion 20, a gap portion 2 in which the heat conduction portion 10 and the joint portion 20 do not exist. are doing.
The void portion 2 is a portion of the heat conductor 1 where the heat conductive portion 10 and the joint portion 20 do not exist. The void 2 normally contains air and gas such as gas generated when the resin material 21 constituting the joint 20 is cured.

By having such a gap portion 2, the gap portion 2 functions as a cushion, and deformation when the heat conductor 1 is pressed, particularly deformation of the joint portion 20, can be absorbed by the gap portion 2. , excessive deformation of the heat conductor 1 as a whole can be suppressed. In addition, it is possible to impart appropriate flexibility to the heat conductor 1, and the adhesion between the member in contact with the heat conductor 1 and the heat conductor 1 can be improved. and the thermal conductor 1 can be made more excellent. In particular, by including resin fibers 22 as described above together with the resin material 21 functioning as a binder, the joining portion 20 can form relatively small gaps 2 in a dispersed manner. Thereby, the adhesion between the heat conducting portion 10 and the joint portion 20 can be improved, and the durability and reliability of the heat conductor 1 can be improved.

The void 2 normally contains air and a gas such as a gas generated when a curable resin material 21' (see FIG. 8, which will be described later) used to form the resin material 21 is cured.
In the heat conductor 1 , the void 2 is provided at least at a site adjacent to the joint 20 .

The ratio of the voids 2 in the heat conductor 1 (the ratio in the natural state; hereinafter the same) is preferably 5% by volume or more and 65% by volume or less, and is 5% by volume or more and 50% by volume or less. is more preferably 6% by volume or more and 40% by volume or less, and most preferably 7% by volume or more and 32% by volume or less.
Thereby, the effect mentioned above is exhibited more notably.

VC [% by volume] is the ratio of the heat conducting portion 10 in the heat conductor 1, VJ [% by volume] is the ratio of the joint portion 20 in the heat conductor 1, and VJ [% by volume] is the ratio of the void portion 2 in the heat conductor 1. When the ratio is VV [% by volume], it is preferable to satisfy the relationship of 25 ≤ [(VJ + VV) / (VC + VJ + VV)] × 100 ≤ 90, and 25 ≤ [(VJ + VV) / (VC + VJ + VV)] × 100 ≤ 70 More preferably, the relationship 31 ≤ [(VJ + VV) / (VC + VJ + VV)] × 100 ≤ 65 is satisfied, and the relationship 37 ≤ [(VJ + VV) / (VC + VJ + VV)] × 100 ≤ 62 is satisfied. Most preferably.
Thereby, the effect mentioned above is exhibited more notably.

The density of the heat conductor 1 in the natural state is preferably 0.6 g/cm ³ or more and 2.5 g/cm ³ or less, more preferably 0.9 g/cm ³ or more and 2.0 g/cm ³ or less. preferable.

By using the above-described materials as materials for forming the heat conducting portion 10 and the joint portion 20 of the heat conductor 1, the overall density can be made lower than that of a conventional copper inlay.

Thereby, the heat conductor 1 can be made particularly lightweight. Further, when the electronic circuit board 100 having the heat conductor 1 is mounted on an electronic device or the like, the weight of the electronic device or the like can be reduced. That is, it is possible to make electronic equipment and the like lighter.
The density of copper used in conventional copper inlays is approximately 8.9 g/cm ³ .

[1-5] Method for manufacturing heat conductor Next, a method for manufacturing a heat conductor will be described.
FIG. 7 is a cross-sectional view schematically showing a sheet for forming a heat conductive portion made of flake graphite. FIG. 8 is a cross-sectional view schematically showing a state in which a bonding portion forming composition is applied to a heat conductive portion forming sheet provided with recesses. FIG. 9 is a diagram schematically showing an example of an apparatus used in the bonding portion forming composition application step and the winding step. FIG. 10 is a diagram schematically showing an incision body obtained in the incision step. FIG. 11 is a diagram schematically showing a state in which the incision body is pressed to make the incision body more flat. FIG. 12 is a diagram schematically showing the state of the cutting process.

The method for manufacturing a heat conductor includes, for example, applying a bonding portion forming composition 20', which is a composition containing a curable resin material 21', to form a heat conductive portion 10 in which a concave portion (hole portion) 11 is formed. A winding step of obtaining a cylindrical wound body 30 by winding the heat conductive portion forming sheet 10 ′ used in the winding roll R2 on the peripheral surface of the winding roll R2, and winding the wound body 30 in the axial direction of the roll A cutting step of cutting in a non-perpendicular direction to obtain the incised body 40 and a curing step of curing the curable resin material 21 ′ contained in the incised body 40 to form the joint 20 .

By winding the heat conductive portion forming sheet 10 ′ to which the joint portion forming composition 20 ′ is applied around the peripheral surface of the roll, for example, compared to the case of using a single sheet raw material, the heat can be reduced. The conductor 1 can be efficiently manufactured. In addition, by curing the curable resin material 21 ′ after cutting the wound body 30 , the cutting can be performed in a softer state than the bonding portion 20 including the resin material 21 . For this reason, the strain generated by winding can be preferably corrected, and when forming the incised body 40 having a higher flatness than the wound body 30, the heat conductive portion corresponding to the heat conductive portion 10 is formed. Therefore, it is possible to effectively prevent the occurrence of delamination, deterioration of adhesion, and the like between the adhesive sheet 10 ′ and the joint portion forming composition 20 ′ corresponding to the joint portion 20 . As a result, the finally obtained thermal conductor 1 is properly strained, and the separation between the thermal conductive part 10 and the joint part 20, the deterioration of the adhesion, the breakage of the joint part 20, the heat It is possible to effectively prevent breakage or the like of the joint between the conductive portions 10, and the heat conductive portion 10 and the joint portion 20 can be firmly adhered to each other.

In addition, in the method for manufacturing a heat conductor, for example, prior to the winding process, bonding by applying a bonding portion forming composition 20 ′ to a heat conductive portion forming sheet 10 ′ provided with a recess (hole) 11 is performed. It may have a portion-forming composition application step.

[1-5-1] Sheet for Forming Heat Conducting Portion The sheet 10′ for forming the heat conducting portion used in the step of applying the composition for forming the joint portion should be the heat conducting portion 10 in the heat conductor 1. FIG.
As the heat conductive portion forming sheet 10', a sheet material made of a material corresponding to the heat conductive portion 10 to be formed is normally used.

It is preferable that the heat conductive portion forming sheet 10' is substantially composed of a single component.
Thereby, the thermal conductivity of the formed thermally conductive portion 10 can be further improved. In general, it is also advantageous in suppressing the manufacturing cost of the heat conductor 1 .

By using a sheet material containing graphite as the heat conductive portion forming sheet 10′, the substantial thermal conductivity between the member in contact with the heat conductor 1 and the heat conductor 1 is improved. At the same time, the manufacturing cost of the heat conductor 1 can be suppressed. In addition, the suppleness and flexibility of the heat conductor 1 can be improved. It is possible to further improve the contact property and the like by moderate deformation when the contact is made. Hereinafter, the sheet material containing graphite is also referred to as "graphite sheet material".

In addition, by using a sheet material made of a metal material as the heat conductive portion forming sheet 10′, substantial thermal conductivity between the member in contact with the heat conductor 1 and the heat conductor 1 can be improved. The manufacturing cost of the heat conductor 1 can be suppressed while making it more excellent. In addition, the dust generation property of the heat conductor 1 can be further reduced due to the strength of the bonding force inside the metal material. In addition, even when a relatively large load is applied to the heat conductor 1, irreversible deformation of the heat conductor 1, such as collapse of the heat conductor 1 due to buckling, etc., is more effectively prevented. . Hereinafter, a sheet material made of a metal material is also referred to as a "metal sheet material".

[1-5-1-1] Graphite sheet material As the graphite sheet material, in addition to graphite, materials other than graphite, such as binders and resin fibers, can be used. It is preferably composed, ie composed substantially of a single component.
Such a graphite sheet material can be produced, for example, by pressing powdery graphite into a sheet.

The graphite is preferably flake graphite.
As a result, the graphite flakes can be preferably oriented in the in-plane direction of the heat-conducting portion 10, and the heat conductivity in the in-plane direction of the heat-conducting portion 10 can be made particularly excellent.

More specifically, when flake graphite is pressed into a sheet, as shown in FIG. 7, flake graphite FG is oriented in the in-plane direction of the sheet. That is, the thickness direction of the flake graphite FG is preferably oriented along the thickness direction of the sheet. When the heat conductor 1 is used, the heat conductivity in the in-plane direction of the heat conducting portion 10 can be made particularly excellent.

Graphite sheet materials include, for example, a pressurization process in which scale-like graphite is pressurized and formed into a sheet, a drying process in which the sheet-shaped graphite is dried, and a sheet-shaped graphite is heated and pressed (heated). It is preferably manufactured by a method including a heating and pressurizing step of pressing.

In the pressurizing step, the graphite is pressurized into a sheet. The pressurization step can be suitably performed at, for example, 10° C. or higher and 35° C. or lower. The press pressure at this time can be, for example, 1 MPa or more and 30 MPa or less.

In the drying step, the sheet-shaped graphite is dried. As a result, volatile components such as excessive moisture can be removed, and the handleability is improved. Moreover, the shape stability and strength of the graphite sheet material are improved.

The drying process can be carried out by reducing pressure, heating, or natural drying. When heating is performed, the heating temperature can be 40° C. or higher and 100° C. or lower.

In the heating and pressurizing step, the sheet-shaped graphite is subjected to a heating and pressurizing treatment in the thickness direction of the sheet. This makes it possible to orient the flake graphite more preferably. Moreover, the shape stability and strength of the graphite sheet material are improved.

The heating temperature in the heating/pressurizing step can be, for example, 100° C. or higher and 400° C. or lower. As a result, it is possible to more effectively prevent moisture, a binder, and the like from unintentionally remaining in the finally obtained graphite sheet material. Moreover, the press pressure in the heating and pressurizing step can be, for example, 10 MPa or more and 40 MPa or less.

As shown in FIG. 7, when the flake graphite FG is compacted into a sheet, near the surface of the graphite sheet material, the flake graphite FG is densely compacted and hardened, while the graphite In the vicinity of the central portion in the thickness direction of the sheet material, the flake graphite FG is roughly consolidated and relatively soft, and has voids 12 . As the heat conductive portion forming sheet 10', when a graphite sheet material obtained by pressing flake graphite into a sheet is used, and the hole portion 11 is provided in the graphite sheet material, the heat conductive portion forming sheet 10' The heat conductive portion 10 formed by the graphite sheet material and the heat conductive portion forming sheet 10 ′ has only the hole portion 11 penetrating from one surface to the other surface, and the other portions are made of graphite The sheet material does not have a gap portion 12 penetrating from one surface of the heat conducting portion 10 to the other surface.

In this way, if the heat conducting portion forming sheet 10′ has the void 12 inside, particularly near the center in the thickness direction, the heat conducting portion forming sheet 10′ will be exposed not only inside the hole 11 but also inside the hole 11. 'The curable resin material 21' can also enter the 'inner space 12', and the adhesion between the heat conductive part 10 and the joint part 20 in the manufactured heat conductor 1, the durability of the heat conductor 1, etc. can be made even better.

As for the density, the density is relatively high near the surface of the graphite sheet material, and the density is relatively low inside the graphite sheet material.

The density of the entire graphite sheet material is preferably 0.3 g/cm ³ or more and 2.1 g/cm ³ or less, more preferably 0.7 g/cm ³ or more and 2.1 g/cm ³ or less.
As a result, the graphite sheet material alone can have particularly excellent thermal conductivity and strength in the plane direction, and the graphite sheet material can have more suitable voids 12 near the center in the thickness direction. It is possible to achieve the effects described above more remarkably.

[1-5-1-2] Metal sheet material As the metal sheet material, in addition to the metal material, a material containing a component other than the metal material, such as a binder or resin fiber, can be used. It is preferably composed of only material, ie substantially composed of a single component.
As the metal sheet material, for example, a metal foil obtained by rolling a metal material into a sheet can be preferably used.

The thickness of the heat conductive portion forming sheet 10 ′ is preferably 5 μm or more and 500 μm or less, and more preferably 20 μm or more and 150 μm or less.

It is preferable that the heat-conducting portion-forming sheet 10′ to be subjected to the bonding portion-forming composition application step is previously provided with recesses (holes) 11 in the thickness direction thereof.
As a result, in the step of applying the joint-forming composition, the joint-forming composition 20′ can be more preferably penetrated into the recess (hole) 11, and the finally obtained heat conductor 1 can be The form of penetration of the resin material 21 into the concave portion (hole) 11 can be made more suitable.

The method for forming the recessed portions (holes) 11 in the heat conductive portion forming sheet 10′ is not particularly limited, but for example, a roll body having a plurality of projections corresponding to the recessed portions (holes) 11 formed on the peripheral surface, The depressions (holes) 11 can be efficiently formed by rotating while pressing the sheet 10' for forming the heat conductive portion against the surface thereof with a predetermined force.

The recessed portions (holes) 11 of the heat conductive portion forming sheet 10 ′ are not limited to being provided by the method described above, and may be provided by other methods. For example, the recessed portion (hole) 11 may be formed by using a member in which a plurality of protrusions corresponding to the recessed portion (hole) 11 are formed on a flat plate, or by using an awl or the like. In addition, the concave portions (holes) 11 are provided in the heat conductive portion forming sheet 10′ by preparing the heat conductive portion forming sheet 10′ that does not have the concave portions (holes) 11 as described above. It may be formed at the same time as the heat conductive portion forming sheet 10' is formed.

The concave portion (hole) 11 of the heat conductive portion forming sheet 10′ may satisfy the same conditions as described in the explanation of the concave portion (hole) 11 of the heat conductive portion 10 described above. can. As a result, the same effect as described above can be obtained.

[1-5-2] Joint-forming composition The joint-forming composition 20' used in the step of applying the joint-forming composition is to be the joint 20 in the heat conductor 1, and is cured. It is a composition containing a flexible resin material 21'.

The curable resin material 21' is not particularly limited as long as the resin material 21 obtained by curing the curable resin material 21' has flexibility. An uncured product and a semi-cured product can be used. As a result, the same effect as described above can be obtained.

Moreover, it is preferable that the curable resin material 21' generate gas in the curing process described later.
Thereby, the void 2 can be preferably formed in the heat conductor 1 .

The joint forming composition 20' may contain resin fibers 22 in addition to the curable resin material 21'.
As a result, when manufacturing the heat conductor 1, there is no need to prepare the resin fiber 22 separately from the joint forming composition 20', and the apparatus used for manufacturing the heat conductor 1 (in particular, the joint forming composition A device with a relatively simple configuration can be used as the device used in the applying step and the winding step.

The joint forming composition 20' may contain metal particles, ceramic particles, spacers, etc. in addition to the components described above.

When the joint-forming composition 20' contains the above components, the joint-forming composition is added so that the content of the finally obtained thermal conductor 1 in the joint 20 is within the above-described range. It is preferable to adjust the content in 20'.

The joint forming composition 20' may contain components other than those described above.
Examples of such components include plasticizers, colorants, antioxidants, ultraviolet absorbers, light stabilizers, softeners, modifiers, rust inhibitors, fillers, electromagnetic wave absorbers such as ferrite, and surface lubricants. agents, corrosion inhibitors, heat stabilizers, lubricants, primers, antistatic agents, polymerization inhibitors, cross-linking agents, catalysts, leveling agents, thickeners, dispersants, anti-aging agents, flame retardants, hydrolysis inhibitors, etc. mentioned.

However, the content of these components in the joint forming composition 20' is preferably 5% by weight or less, more preferably 1% by weight or less.

Also, the joint forming composition 20' preferably does not contain a solvent component. As a result, it is possible to prevent the solvent component from unintentionally remaining in the heat conductor 1 finally obtained, and the reliability of the heat conductor 1 can be improved.

[1-5-3] Step of applying composition for forming joints In the step of applying composition for forming joints, a joint containing a curable resin material 21' is provided on at least one surface of the sheet 10' for forming a heat conductive portion. A forming composition 20' is applied.

Examples of the method for applying the bonding portion forming composition 20′ to the surface of the heat conductive portion forming sheet 10′ include a bar coater, a roll coater, a reverse roll coater, a gravure coater, a die coater, a kiss coater, a rod coater, and a dip coater. Examples include a method of coating using either a coater or a spray coater.

As a result, the bonding portion forming composition 20 ′ can be continuously and appropriately applied to the surface of the heat conductive portion forming sheet 10 ′, and the reliability of the manufactured heat conductor 1 and the heat conductor 1 It is advantageous to improve the productivity of

The bonding portion forming composition 20' may be applied to only one surface side of the heat conductive portion forming sheet 10', or may be applied to both surfaces of the heat conductive portion forming sheet 10'. In the case of having holes 11, as shown in FIG. 9, it is preferable to apply the bonding portion forming composition 20' from one side of the heat conductive portion forming sheet 10'.

As a result, the curable resin material 21 ′ can be favorably penetrated into the inside of the hole 11 . More specifically, by applying the bonding portion forming composition 20′ from one surface side of the heat conductive portion forming sheet 10′, the air existing in the holes 11 is removed from the heat conductive portion forming sheet 10′. , and the curable resin material 21' can more preferably enter the hole 11. As shown in FIG. Further, when the heat conductive portion forming sheet 10 ′ has the voids 12 in addition to the holes 11 , the voids 12 inside the heat conductive portion forming sheet 10 ′ through the holes 11 can also be filled. , the curable resin material 21' can preferably penetrate.

At this time, the joint forming composition 20' is preferably applied using a kiss coater.

In addition, in FIG. 8, a graphite sheet material composed of flake graphite FG is shown as the heat conductive portion forming sheet 10′, but even if the heat conductive portion forming sheet 10′ other than this is used, the above-mentioned You can get the effect like

However, by using the graphite sheet material as described above as the heat conductive portion forming sheet 10 ′, the following effects are also obtained. That is, when the heat conductive portion forming sheet 10′ is a graphite sheet material as described above, near the surface of the graphite sheet material, the flake graphite FG is densely compacted and hardened, while the graphite sheet In the vicinity of the central portion in the thickness direction of the material, the flake graphite FG is coarsely compacted and relatively soft, and has voids 12 . For this reason, the curable resin material 21 ′ can also preferably penetrate into the voids 12 inside the heat conductive portion forming sheet 10 ′ through the holes 11 . As a result, the adhesiveness between the heat conducting portion 10 and the joint portion 20 in the manufactured heat conductor 1, the durability of the heat conductor 1, and the like can be further improved.

This step can be performed using, for example, the apparatus shown in FIG. More specifically, a raw fabric roll R1 is prepared by winding the prefabricated heat conductive portion forming sheet 10' into a roll. Then, one end of the heat conductive portion forming sheet 10′ is pulled out from the original fabric roll R1, and a joint portion forming composition 20′ is applied from one side of the heat conductive portion forming sheet 10′ using a kiss coater M10. Give.

The kiss coater M10 is a device that coats a sheet using one or several rolls, and can coat only the portion where the coating roll M11 and the sheet are in contact.

The kiss coater M10 includes a coating roll M11 that is driven to rotate in the direction of the arrow by a motor (not shown), a liquid receiving pan M12 that stores the joint forming composition 20′, and a tip that is brought into contact with the surface of the coating roll M11. and a squeegee M13 for keeping the film thickness of the joint forming composition 20′ on the surface of the roll constant. 'be immersed in In addition, the heat conductive portion forming sheet 10′ is conveyed while being guided by the guide rolls M14, M14, so that when the joint portion forming composition 20′ is applied, it is conveyed in contact with the upper surface of the coating roll M11. be. As a result, when the coating roll M11 rotates, the bonding portion forming composition 20′ in the liquid receiving pan M12 is pumped up along with the coating roll M11 due to the rotation, and is adjusted to a predetermined coating amount by the squeegee M13. After that, it is applied to the surface of the heat conductive portion forming sheet 10'. The liquid receiving pan M12 is supplied with the joint forming composition 20' by a pump from a supply tank (not shown) so that the height of the joint forming composition 20' in the liquid receiving pan M12 is kept constant. controlled by

By using the kiss coater M10, the joint forming composition 20' can be applied without immersing the heat conductive portion forming sheet 10' in the joint forming composition 20'. , it is possible to continuously and efficiently apply a constant amount of the joint forming composition 20'.

In the bonding portion forming composition adhesion step, it is preferable to include air bubbles between the heat conductive portion forming sheet 10' and the bonding portion forming composition 20'.
Thereby, after the resin material 21 is cured, the gap 2 can be preferably formed between the heat conducting portion 10 and the joint portion 20 .

As a method for including air bubbles between the heat conducting portion forming sheet 10′ and the joint forming composition 20′, for example, the surface shape of the heat conducting portion forming sheet 10′ and the joint forming composition The viscosity of 20' and the wettability with respect to the heat conductive portion forming sheet 10' can be adjusted.

Further, after the bonding portion forming composition 20 ′ is adhered to the heat conductive portion forming sheet 10 ′, the gas generated during the curing reaction can also be used to form bubbles (form the voids 2 ).

This step is preferably performed using the heated joint forming composition 20' so that the viscosity of the joint forming composition 20' becomes lower than the viscosity at room temperature (20° C.).
As a result, after the completion of this step, for example, in the winding step, the bonding portion forming composition 20′ applied to the heat conductive portion forming sheet 10′ is cooled, and the viscosity of the bonding portion forming composition 20′ is reduced. , the viscosity can be lower than that in this step. As a result, it is possible to more effectively prevent the unintentional loss of the joint forming composition 20′ applied to the heat conducting portion forming sheet 10′ in a step subsequent to the joint forming composition application step. can be prevented.

The heating temperature of the joint forming composition 20' in this step is not particularly limited, but is preferably set so that the viscosity of the joint forming composition 20' satisfies the following conditions.

The viscosity of the bonding portion forming composition 20′ when applying the bonding portion forming composition 20′ to the heat conductive portion forming sheet 10′ is preferably 500 mPa·s or more and 50000 mPa·s or less, and is preferably 2000 mPa·s. s or more and 40000 mPa·s or less is more preferable.

Thereby, the composition 20' for forming a joint portion can be more suitably applied to the sheet 10' for forming a heat conductive portion in a predetermined thickness. Further, when the heat conductive portion forming sheet 10 ′ has the concave portion (hole) 11 , the bonding portion forming composition 20 ′ can more preferably penetrate into the concave portion (hole) 11 .
The viscosity of the joint forming composition 20' can be obtained by measurement according to JIS Z8803:2011.

Further, for example, in this step, a plurality of types of joint forming compositions 20' may be used, or a material containing only a part of the constituent components of the joint forming composition 20' described above and other components may be used. Materials containing some components may be used in separate combinations.

[1-5-4] Winding step In the winding step, the heat conductive portion forming sheet 10 ' to which the joint portion forming composition 20 ' is applied is wound around the peripheral surface of the winding roll R2, and formed into a cylindrical shape. to obtain the wound body 30 of

The wound body 30 obtained in this way has, from the center toward the outer peripheral direction, a portion composed of the heat conductive portion forming sheet 10′ and a portion composed of the joint portion forming composition 20′. have an alternating structure.

Note that FIG. 9 shows a case where the heat conductive portion forming sheet 10′ is guided and conveyed by the guide rolls M14 and M14, but the heat conductive portion forming sheet 10′ is However, if necessary, the guide rolls may be used to change the direction of transport.

In the illustrated configuration, the heat conductive portion forming sheet 10' to which the joint portion forming composition 20' is applied is wound around the peripheral surface of the winding roll R2 having a perfectly circular cross section. However, it may be wound on the peripheral surface of a roll having an elliptical, polygonal, or track-shaped cross section.

In the winding step, a resin fiber sheet (a woven fabric, a nonwoven fabric, or the like) containing the resin fibers 22 may be wound around the winding roll R2 together with the heat conductive portion forming sheet 10' described above.
In this case, the resin fiber sheet may be one to which the joint forming composition 20' is applied by the same method as described above, or one to which the joint forming composition 20' is not applied. may be

When the resin fiber sheet to which the joint forming composition 20′ is applied is used, the heat conductive portion forming sheet 10′ is a sheet to which the joint forming composition 20′ is applied as described above. may be used, or one to which the joint forming composition 20' is not applied may be used. In other words, in the step of applying the joint forming composition, the joint forming composition 20' may be adhered to the resin fiber sheet instead of the heat conducting portion forming sheet 10'.
Moreover, when a resin fiber sheet is used, it may be used with an adhesive applied to at least part of its surface.

By using the resin fiber sheet for the production of the heat conductor, the resin fibers 22 can be preferably oriented in the in-plane direction of the joint 20, so that the resin fibers 22 can be dispersed more uniformly. , the overlapping state of the resin fibers 22 can also be made uniform. As a result, the tensile strength of the joint portion 20 is improved, and the thickness of the joint portion 20 can be made more uniform.

When a resin fiber sheet is used, the thickness of the resin fiber sheet is preferably 3 μm or more and 300 μm or less, more preferably 5 μm or more and 100 μm or less.

[1-5-5] Cutting Step In the cutting step, the wound body 30 is cut open in a direction non-perpendicular to the axial direction of the take-up roll R2 to obtain the cut body 40. FIG.

By incising the wound body 30 before the curing step of curing the curable resin material 21', the bonding portion 20 is softer than the joint 20 including the resin material 21 (cured product of the curable resin material 21'). state can be cut.

In this step, the wound body 30 is laminated in a direction non-perpendicular to the axial direction of the cylindrical winding roll R2 from one end to the other end in the axial direction of the winding roll R2. A notch is made in the direction, and the wound body 30 is removed from the take-up roll R2 while being opened at the cut portion to form an incised body 40.例文帳に追加

The direction in which the wound body 30 is cut open is not particularly limited as long as it is a direction non-perpendicular to the axial direction of the winding roll R2. It may be in an oblique direction with respect to the axial direction of the roll. In addition, the wound body 30 may be cut open in different directions. For example, it may have a part that is cut in a direction substantially parallel to the axial direction of the winding roll R2 and a part that is cut in a direction oblique to the axial direction of the roll.

A method for cutting the wound body 30 is not particularly limited, but examples thereof include a method using a band saw, a saw, a cutter, a trimming cutter, a laser, an ultrasonic cutter, a water cutter, and the like.

[1-5-6] Curing Step In the curing step, the curable resin material 21' contained in the joint forming composition 20' is cured in the incised body 40. FIG.
After the incision process, a curing process for curing the curable resin material 21' contained in the incision body 40 may be performed.

As shown in FIG. 10, when the wound body 30 is cut open to form the incised body 40, the incised body 40 is normally in a curved state. When the curable resin material 21 ′ is cured before cutting the wound body 30 , if an attempt is made to improve the flatness of the curved incised body 40 , the difference in curvature between the inner circumference and the outer circumference of the incised body 40 Delamination and deterioration of adhesion between the heat-conducting portion 10 and the joint portion 20, breakage of the joint portion 20, breakage of the joint between the heat-conducting portions 10, and the like are likely to occur. On the other hand, by performing a process of curing the curable resin material 21' on the incised body 40 which has been made flat by incising the wound body 30, the occurrence of the above problems can be effectively prevented. can do.

This step can be performed, for example, by curing the curable resin material 21' while the inner peripheral side and the outer peripheral side of the incision body 40 are in contact with a flat surface.
More specifically, for example, as shown in FIG. 11, the incised body 40 is sandwiched between two flat plates 90 and pressure is applied to increase the flatness of the heat conducting portion 10 and the joint portion 20. Then, the curable resin material 21 ′ can be cured to form the resin material 21 .

Although the pressure at this time is not particularly limited, it is preferably more than 0 MPa and 100 MPa or less, more preferably 10 MPa or more and 50 MPa or less.

If the pressure is less than the lower limit, it may be difficult to sufficiently improve the flatness of the heat conducting portion 10 and the joint portion 20 . On the other hand, when the pressure exceeds the upper limit, the curable resin material 21' is significantly washed out from between the adjacent heat conducting portion forming sheets 10', making it difficult to form the joint portion 20 with a desired thickness. could become

In addition, by performing the curing process while pressing the incised body 40, peeling between the heat conducting portion 10 and the joint portion 20, deterioration in adhesion, breakage of the joint portion 20, and failure to join the heat conducting portions 10 to each other. Breakage or the like can be prevented more effectively, and the durability of the heat conductor 1 can be improved.

When the curable resin material 21' is a thermosetting resin, the heating temperature varies depending on the conditions of the curable resin material 21', but is preferably 80° C. or higher and 220° C. or lower, and 100° C. or higher and 190° C. or lower. is more preferable.
Thereby, the curable resin material 21' can be preferably cured.

The thermal conductor 1 can be obtained by processing it into a predetermined shape as necessary through each of the steps described above.

[1-5-7] Cutting step When the heat conductor 1 to be manufactured is in the form of a block, after the above-described curing step, the block on which the heat conducting part 10 and the joint part 20 are exposed on both sides A cutting process is performed to cut into a shape.
Thereby, for example, a block-shaped heat conductor 1 having a desired thickness can be obtained.

After the curing step, for example, by cutting along the cutting lines AA' and BB' in FIG. 12, a block-shaped heat conductor 1 having a thickness of _T3 can be obtained.
Here, even if the thickness _T3 of the heat conductor 1 to be manufactured is relatively small, the curable resin material 21' becomes the resin material 21 with higher shape stability through the curing process. Therefore, the heat conductor 1 can be easily cut.

The cutting method is not particularly limited, but examples thereof include methods using a cutter, a trimming cutter, a laser, an ultrasonic cutter, a water cutter, and the like.

The cutting direction may be substantially parallel to the lamination direction (thickness direction of the incision body 40) or may be oblique to the lamination direction (thickness direction of the incision body 40). FIG. 12 shows how the incision 40 is cut substantially parallel to the stacking direction.

The surface of the heat conductor 1, particularly the surface where the heat conducting portion 10 and the joint portion 20 are exposed, may be subjected to a polishing treatment. Thereby, the surface roughness of the heat conductor 1 can be suitably adjusted.

The surface roughness Ra of the heat conductor 1 in a natural state, that is, in a state where no external force is applied, is preferably 0.1 μm or more and 80 μm or less, and more preferably 0.1 μm or more and 10 μm or less.
As a result, the surface shape of the member in contact with the heat conductor 1 can be more preferably followed, and the substantial thermal conductivity between the member and the heat conductor 1 can be improved. can.
The surface roughness Ra of the heat conductor 1 can be measured, for example, by a method conforming to JIS B 0601-2013.

In the electronic circuit board 100 provided with such a heat conductor 1, the thickness of the substrate 110 at the portion where the through hole 111 is provided is T1 [mm], and the heat conductor 1 in the thickness direction of the substrate 110 is naturally When the length in the state is T2 [mm], it is preferable to satisfy the relationship of 0.70 ≤ T1/T2 ≤ 0.99, and it is preferable to satisfy the relationship of 0.75 ≤ T1/T2 ≤ 0.98. More preferably, it satisfies the relationship 0.80≦T1/T2≦0.97.
As a result, the adhesion of the heat conductor 1 to the member in contact with the heat conductor 1 can be improved, the interfacial thermal resistance can be kept low, and the substantial thermal conductivity can be increased.

In addition, the heat conductor 1 is in its natural state when one of the two surfaces in the depth direction of the through hole 111 (both surfaces in contact with different members) is the top surface and the other surface is the bottom surface. S1 [mm ² ] is the sum of the areas of the top surface and the bottom surface of the thermal conductor 1, and S2 [mm ² ] is the area of the side surface of the heat conductor 1 in its natural state. more preferably satisfy the relationship 0.4≦S1/S2≦7.0, and further preferably satisfy the relationship 0.5≦S1/S2≦5.0.
As a result, a sufficient contact area can be secured between the heat conductor 1 and the members that come into contact with the heat conductor 1, and the above-described effects of the present invention are exhibited more remarkably.

In this specification, the term "side surface area" refers to the area of the entire side surface, for example, when the heat conductor 1 has a quadrangular prism shape, it refers to the sum of the areas of four side surfaces.

[1-6] Another Configuration Example of Heat Conductor Next, another configuration example of the heat conductor will be described.
FIG. 13 is a perspective view schematically showing another example of the heat conductor. 14 is a longitudinal sectional view of the heat conductor shown in FIG. 13, FIG. 14(a) is a sectional view taken along the section line CC', and FIG. It is a cross-sectional view in.
In the heat conductor 1 shown in FIGS. 13 and 14, a plurality of heat conducting portions 10 are provided in an island shape when viewed from the first direction.

As a result, while suppressing variations in thermal conductivity at each part in the plane of the heat conductor 1 (direction of the xy plane shown in FIG. 13), the flexibility of the heat conductor 1 as a whole is easily improved. , the effects of the present invention described above can be exhibited more remarkably.

In this specification, the term “island shape” refers to a state in which a plurality of heat conducting portions 10 are interspersed in the joint portion 20 without being continuous. In other words, the heat-conducting portion 10 is independent of the other heat-conducting portions 10 in both the x-direction and the y-direction.

In the heat conductor 1 shown in FIG. 13, a plurality of heat conducting portions 10 are arranged in a zigzag pattern when viewed from the first direction. In other words, first rows 10a in which a plurality of heat conducting portions 10 are arranged in the x direction and second rows 10b are alternately arranged in the y direction so that the heat conducting portions 10 are alternately arranged. there is
Thereby, the effect mentioned above can be exhibited more notably.

It is preferable that the heat-conducting portions 10 of the first row 10a and the heat-conducting portions 10 of the second row 10b at least partially overlap each other in the y-direction.
Thereby, the effect mentioned above can be exhibited more notably.

The width of the heat conductive portion 10 indicated by _w10 in FIG. 13 when viewed from the first direction is preferably 1 mm or more and 30 mm or less, more preferably 5 mm or more and 20 mm or less, and 7 mm or more and 15 mm. More preferably:

As a result, while the ratio of the heat conductive portion 10 in the heat conductor 1 is sufficiently high, the flexibility of the heat conductor 1 as a whole can be easily improved, and the above-mentioned effects can be achieved more reliably. It can be exhibited remarkably.

When the heat conductor 1 is planarly viewed from the first direction, the distance between the adjacent heat conducting parts 10 indicated by _g10 in FIG. is more preferable, and more preferably 3 μm or more and 1000 μm or less.

As a result, while the ratio of the heat conductive portion 10 in the heat conductor 1 is sufficiently high, the flexibility of the heat conductor 1 as a whole is easily improved, and the above-described effects are exhibited more remarkably. be able to.

In this specification, the “interval between adjacent heat conducting portions 10 ” means a gap as the shortest distance between adjacent heat conducting portions 10 .

In addition, although FIG. 13 shows a case where the plurality of heat conducting portions 10 are arranged in a zigzag pattern, the plurality of heat conducting portions 10 may be arranged in a manner other than the zigzag pattern. . The plurality of heat conducting parts 10 may be arranged regularly or may be arranged at random.

As shown in FIG. 14, in the first row 10a and the second row 10b of the heat conducting portions 10, the inclination direction of the heat conducting portions 10 (through heat conducting portions 10c) with respect to the surface normal direction V1 is , is reversed.

The inclination direction of the penetrating heat-conducting portions 10c of the first row 10a with respect to the normal direction V1 of the surface is the plus (+) direction, and the inclination of the penetrating heat-conducting portions 10c of the second row 10b with respect to the normal direction of the surface. Let the direction be the minus (-) direction.

That is, the through heat conducting portions 10c of the first row 10a are inclined by an angle θ1 in the positive direction with respect to the normal direction V1 of the surface, and the through heat conducting portions 10c of the second row 10b are inclined perpendicular to the surface. It is inclined at an angle θ2 in the negative direction with respect to the linear direction V1.

Thus, the provision of through heat conducting portions 10c inclined in different On the other hand, by providing the penetrating heat conducting portion 10c inclined in the negative direction, for example, even when a relatively large load is applied to the heat conductor 1, the heat conductor 1 collapses due to buckling or the like. , the irreversible deformation of the heat conductor 1 can be more effectively suppressed, and the durability of the heat conductor 1 can be further improved. Further, when the heat conductor 1 is compressed from the first direction, the surface pressure is more likely to be applied to the heat conductor 1, and the adhesion between the heat conductor 1 and the member in contact with the heat conductor 1 is further improved. can be enhanced. In addition, when pressure is applied to the heat conductor 1 in the first direction, the pressure includes a force component in the direction that presses the heat conductive portion 10 and the joint portion 20, thereby causing the heat conductive portion The adhesiveness between 10 and joint portion 20 is also further enhanced.

In particular, the through heat conducting portions 10c inclined in the positive direction with respect to the normal direction V1 of the surface and the through heat conducting portions 10c inclined in the negative direction with respect to the normal direction V1 of the surface are alternately arranged. As a result, the effects described above can be exhibited more remarkably.

As shown in FIG. 14, the absolute values of the angles θ1 and θ2 formed by the surface normal direction V1 and the extending direction _e10 of the penetrating heat conducting portion 10c are preferably 3° or more and 45° or less. It is more preferably 5° or more and 40° or less, and further preferably 8° or more and 35° or less.

As a result, when the heat conductor 1 is compressed from the first direction, the surface pressure is easily applied to the heat conductor 1, and the adhesion between the heat conductor 1 and the member in contact with the heat conductor 1 is improved. can be enhanced. In addition, when pressure is applied to the heat conductor 1 in the first direction, the pressure includes a force component in the direction that presses the heat conductive portion 10 and the joint portion 20, thereby causing the heat conductive portion Adhesion between 10 and joint portion 20 is also enhanced.

The angles θ1 and θ2 may have different sizes, but are preferably the same.

Also, the angle is not a precise numerical value in a mathematical sense, and may include normal errors in the technical field of the present invention. For example, a difference of less than 1° is interpreted as the same angle as an error.

The direction of inclination of the heat conducting portion 10 is not particularly limited, but when the heat conducting portion 10 (the member 10′ for forming the heat conducting portion) has a strip shape, the surface direction of the heat conducting portion 10 is the same as that of the surface of the surface. is preferably inclined with respect to the normal direction V1 of .

As a result, for example, even when a relatively large load is applied to the heat conductor 1, irreversible deformation of the heat conductor 1, such as collapse of the heat conductor 1 due to buckling, can be effectively prevented. can be suppressed, and the durability of the heat conductor 1 can be further improved. Further, when the heat conductor 1 is compressed from the first direction, the surface pressure is more likely to be applied to the heat conductor 1, and the adhesion between the heat conductor 1 and the member in contact with the heat conductor 1 is further improved. can be enhanced. In addition, when pressure is applied to the heat conductor 1 in the first direction, the pressure includes a force component in the direction that presses the heat conductive portion 10 and the joint portion 20, thereby causing the heat conductive portion The adhesiveness between 10 and joint portion 20 is also further improved.

[1-7] Another Configuration Example of Electronic Circuit Board Next, another configuration example of the electronic circuit board of the present invention will be described.
FIG. 15 is a cross-sectional view schematically showing another example of the electronic circuit board of the present invention. FIG. 16 is a plan view schematically showing another example of the electronic circuit board of the present invention. 17A and 17B are diagrams schematically showing another example of the electronic circuit board of the present invention, where (A) is a cross-sectional view and (B) is a plan view.

As shown in FIG. 15, an electronic circuit board 100 has at least one of an insulating layer 101 and an insulating layer 102 disposed inside a through hole 111, in other words, between members disposed on both sides of the substrate 110. may be

The insulating layer 101 is arranged as an intermediate layer of the heat conductor 1 and the insulating layer 102 is arranged as a surface layer of the heat conductor 1 .
As a result, it is possible to suitably prevent the occurrence of problems such as an electrical short circuit in the electronic circuit.

Examples of the material forming the insulating layer 101 as the intermediate layer of the heat conductor 1 include ceramics such as AlN, Si ₃ N ₄ and BN.

The insulating layer (intermediate layer) 101 has, for example, a two-stage configuration of the heat conductors 1 arranged in the through holes 111, and a thin plate made of ceramics as described above is sandwiched between the two heat conductors 1. Formed by

Examples of the material forming the insulating layer 102 as the surface layer of the heat conductor 1 include PCM (Phase Change Material). PCM is softened by heat to improve adhesion, thereby exhibiting excellent heat dissipation performance.

The insulating layer (surface layer) 102 is formed, for example, by coating or forming a film of PCM on the surface of the thermal conductor 1 .

Part of the PCM preferably penetrates inside the heat conductor 1 . Thereby, the above effect can be made more remarkable.

As shown in FIG. 16, when a predetermined in-plane direction of the substrate 110 is the Y-axis direction, and a predetermined in-plane direction of the substrate 110 is the X-axis direction and is perpendicular to the Y-axis direction, The heat conductor 1 preferably has a thermal conductivity in the Y-axis direction lower than that in the X-axis direction.

In the thermal conductor 1, for example, in the plane of the substrate 110, in other words, in the surface that contacts the member, the extending direction of the thermal conductive portion 10 and the joint portion 20 is the X-axis direction, and the thermal conductive portion 10 and the joint portion 20 is arranged in the through-hole 111 so that the direction of lamination with 20 is the Y-axis direction.
In the configuration shown in FIG. 16, the vertical direction in the drawing is the X-axis direction, and the horizontal direction in the drawing is the Y-axis direction.

Thereby, anisotropy can be imparted to the in-plane thermal conductivity of the substrate 110 via the thermal conductor 1 . Specifically, the thermal conductivity in the Y-axis direction within the plane of the substrate 110 can be suitably controlled so as to be lower than the thermal conductivity in the X-axis direction.

Further, as shown in FIG. 16, the electronic circuit board 100 may be provided with components other than the above-described members, such as the power semiconductor element 120 and the cooling unit 130 .

In the electronic circuit board 100, it is arranged on the Y-axis extension line of the portion of the substrate 110 where the heat conductor 1 is provided, and on the X-axis extension line of the portion of the substrate 110 where the heat conductor 1 is provided. Preferably, components 150 that are more susceptible to heat than components 140 that are exposed to heat are arranged.

As a result, the heat from the power semiconductor element 120, which is a heating element, is suitably suppressed from being transmitted in the Y-axis direction via the substrate 110, and the influence of the heat on the component 150 can be effectively suppressed. .

Components 150 that are relatively susceptible to heat include, for example, electrolytic capacitors, system-on-a-chip (SOC), aluminum electrolytic capacitors, and the like.

Further, in the electronic circuit board 100 shown in FIG. 17, a heat spreader 160 is arranged between the power semiconductor element 120 and the board 110, for example.
Thereby, the heat of the power semiconductor element 120 can be radiated more efficiently.
In this case, it is preferable to arrange the through-holes 111 and the heat conductor 1 according to the shape of not only the power semiconductor element 120 but also the heat spreader 160 .
Thereby, the heat of the power semiconductor element 120 can be radiated more efficiently.

Thus, even if the heat conductor 1 has a complicated shape, it can be dealt with by cutting the heat conductor 1 into a predetermined shape. can respond.

Further, for example, in the substrate 110 on which the power semiconductor element 120 is arranged on one surface 110a side, if sufficient space cannot be secured on the other surface 110b side, the substrate 110 may be A cooling unit (not shown) may be arranged on the side of 110, for example, on the right side in the example shown in FIG. In that case, the heat of the power semiconductor element 120 is conducted laterally of the substrate 110 via the heat spreader 160 .

At this time, it is preferable that the direction connecting the heat conductor 1 and the cooling unit is the X-axis direction. In other words, it is preferable to dispose the heat conductor 1 so that the extending direction of the heat conducting portion 10 and the joint portion 20 is the X-axis direction.
In the configuration shown in FIG. 17B, the horizontal direction in the drawing is the X-axis direction, and the vertical direction in the drawing is the Y-axis direction.
As a result, the heat of the power semiconductor element 120 can be more efficiently conducted to the side of the substrate 110 to be dissipated.

In addition, when the electronic circuit board 100 has a plurality of heat conductors 1, these conditions may be different from each other. Moreover, when the electronic circuit board 100 has a plurality of heat conductors 1, at least one heat conductor 1 preferably satisfies the above conditions, and the plurality of heat conductors 1 satisfy the above conditions. is more preferable, and it is even more preferable that all the heat conductors 1 satisfy the above conditions.
As a result, the above-described effects of the present invention are exhibited more remarkably.

Since such an electronic circuit board 100 includes the heat conductor 1 having substantially excellent thermal conductivity, it is possible to more efficiently dissipate heat from the electronic components, which are heat generating bodies, and to improve the performance of devices and systems. It is possible to more effectively reduce the risks such as shortening of the service life and malfunction.

In particular, when the power semiconductor device 120 is used as the electronic component, the amount of heat generated tends to be large, so the above-described effects can be particularly remarkable.

[2] Method for Manufacturing Electronic Circuit Board Next, a method for manufacturing an electronic circuit board according to the present invention will be described.
FIG. 18 is a cross-sectional view schematically showing an example of the method for manufacturing an electronic circuit board of the present invention.

The method for manufacturing an electronic circuit board according to the present embodiment includes a board preparation step of preparing a board 110 having through holes 111, and an electronic component joining step of joining and soldering an electronic component to a portion of the board 110 provided with the through hole 111. a heat conductor inserting step of inserting a flexible heat conductor 1 into the through hole 111; and a cooling unit fixing step for fixing the cooling unit 130 on the side.
As a result, the electronic circuit board 100 having substantially excellent thermal conductivity in the thickness direction of the board 110 can be manufactured more preferably.

In the following description, the case where the power semiconductor device 120 is used as an electronic component will be mainly described.

[2-1] Substrate Preparing Step First, in the substrate preparing step, the substrate 110 having the through holes 111 is prepared.
As shown in FIG. 18A, the substrate 110 may have the through holes 111 formed in advance, or the substrate 110 without the through holes 111 is prepared, and the A hole 111 may be formed.

[2-2] Electronic Component Bonding Step In the electronic component bonding step, the power semiconductor element 120 is fixed to the portion on the one surface 110a side of the substrate 110 where the through hole 111 is provided.
As shown in FIG. 18B, the power semiconductor element 120 is fixed on one surface 110a of the substrate 110 by soldering using solder 121. As shown in FIG. At this time, power semiconductor element 120 is fixed on substrate 110 so as to cover through hole 111 .

[2-3] Heat Conductor Inserting Step In the heat conductor inserting step, the flexible heat conductor 1 is inserted into the through hole 111 .

As shown in FIG. 18C, the in-plane direction of the heat-conducting portion 10 is the thickness direction of the substrate 110, and the stacking direction of the heat-conducting portion 10 and the bonding portion 20 is the in-plane direction of the substrate 110. , the heat conductor 1 is inserted into the through-hole 111 .
Thereby, the thermal conductivity in the thickness direction of the substrate 110 can be made excellent.

Moreover, it is preferable that the length of the thermal conductor 1 in the natural state in the thickness direction of the substrate 110 is longer than that of the substrate 110 . In other words, the heat conductor 1 inserted into the through hole 111 preferably protrudes from the through hole 111 on the other surface 110 b side of the substrate 110 .

[2-4] Cooling Unit Fixing Step In the cooling unit fixing step, the cooling unit 130 is fixed to the surface of the substrate 110 opposite to the surface on which the power semiconductor element 120 is provided so as to come into contact with the heat conductor 1. do.
As shown in FIG. 18D, the cooling unit 130 is fixed on the other surface 110b of the substrate 110 by screwing with screws 131. As shown in FIG.

At this time, the part of the thermal conductor 1 protruding from the substrate 110 is pressed by the cooling unit 130 , so that the thermal conductor 1 is pressed in the thickness direction of the substrate 110 . As a result, the heat conductor 1, the power semiconductor element 120 and the cooling unit 130 can be brought into close contact with each other, and substantial heat conductivity can be made particularly excellent.

The electronic circuit board 100 is obtained by disposing the insulating layer and other members as described above, if necessary, through the steps described above.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these.

For example, in the above description, the case in which one thermal conductor is inserted into one through-hole has been mainly described, but two or more thermal conductors may be inserted into one through-hole. .

Further, in the above description, the case where only the heat conductor is inserted into the through hole has been mainly described, but a combination of the heat conductor and the copper inlay may be inserted into the through hole.

In addition, in the above description, the case where a block-shaped heat conductor cut to match the shape of the through-hole is inserted is mainly described. It may be In this case, the curved heat conductor is energized when it tries to recover. In other words, the thermal conductor is pressed against the inner wall surface of the through-hole by the restoring elastic force. As a result, it is possible to suitably prevent the heat conductor from unintentionally falling out of the through hole.

Further, in the above-described embodiments, the description is centered on the case where the board that constitutes the electronic circuit board is provided with through-holes penetrating in the thickness direction of the board as through-holes to which heat conductors are applied. However, the substrate may be provided with a non-penetrating through-hole that does not penetrate in the thickness direction of the substrate as the through-hole to which the heat conductor is applied. In such a case, the heat conductor applied to the non-penetrating through-hole is, for example, one surface of the non-penetrating through-hole (bottomed recess) in the depth direction (the surface on the bottom side of the non-penetrating through-hole). may be in contact with a copper thin plate (heat conductive layer) that constitutes the That is, in the present invention, one of the different members may be the substrate. In the case of such a configuration, heat can be suitably conducted (heat diffused) in the plane direction of the substrate (copper thin plate) through the copper thin plate provided in the substrate.

Further, the electronic circuit board is not limited to those manufactured by the method described above. For example, the method for manufacturing the electronic circuit board may further include other steps in addition to the steps described above.

Also, in the above description, the method of manufacturing an electronic circuit board is described by using the method having the substrate preparation step, the electronic component bonding step, the heat conductor inserting step, and the cooling unit fixing step in this order. For example, the electronic circuit board may be manufactured by a method in which the order of these methods is changed.

The electronic circuit board according to the present invention comprises the steps of: preparing a board having a through hole; inserting a flexible thermal conductor into the through hole; With one surface in contact with another member, while applying surface pressure to the electronic component with the other surface opposite to the one surface, the electronic component and the heat conductor are in contact with each other, and soldering the electronic component to the substrate. By adopting such a method, for example, the heat conductor can be preferably brought into close contact with the different member without screwing.

Further, in the above description, the case where the heat conducting portion and the joint portion constituting the heat conductor are planar has been mainly explained. At least a part thereof may have a non-planar shape, such as a curved surface, a curved surface, or the like.

Further, in the above description, the case where each heat conducting portion constituting the heat conductor is provided with a hole portion has been described as a representative example. The portion may not have a hole.

In addition, instead of or in addition to the above-described holes, the heat-conducting portion may be provided with recesses that do not penetrate in the thickness direction of the heat-conducting portion, that is, bottomed recesses. Further, the heat conducting portion may not have the concave portion.

Moreover, the heat conductor may have a structure other than the heat conducting portion, the joint portion, and the gap portion described above.

In addition, the heat conductor is not limited to those manufactured by the above method. post-treatment step, etc.).

Further, the formation of the holes in the heat conductive portion forming sheet may be performed after the heat conductive portion forming sheet is pulled out from the original fabric roll. More specifically, for example, the heat conductive portion forming sheet in which the hole is not formed is pulled out from the original fabric roll and before the bonding portion forming composition is applied. A hole may be formed in the forming sheet, or at the same timing as applying the bonding portion forming composition to the heat conductive portion forming sheet in which the hole is not formed, the heat conductive portion forming sheet A hole may be formed.

Further, in the above description, the method of manufacturing the heat conductor using the method having the winding process, the incision process, and the curing process in this order has been described. , a method that does not include some of these steps, a method that replaces some of these steps, or the like, may be used to manufacture the heat conductor. More specifically, for example, the heat conductor is obtained by superimposing a plurality of sheets for forming a heat conductive portion to which a composition for forming a joint is applied, instead of a method including a winding step and a cutting step. After that, it may be manufactured using a method in which a curing step is performed.

Further, in the above description, a method of manufacturing a heat conductor by winding a sheet for forming a heat conductive portion to which a composition for forming a joint is applied to form a wound body and cutting the wound body is described. However, the heat conductor may be produced by, for example, a method of laminating a sheet of the heat conductive portion forming member to which the joint portion forming composition is adhered to form a laminate.

Moreover, in the method for manufacturing a heat conductor, at least part of the order of the steps described above may be changed.

Reference Signs List 1: Thermal conductor 2: Air gap 10: Thermal conductive portion 10a: First row 10b: Second row 10c: Penetrating thermal conductive portion 10': Sheet for forming thermal conductive portion (member for forming thermal conductive portion)
11: hole (recess)
12: Gap 20: Joint 20': Joint forming composition 21: Resin material 21': Curable resin material 22: Resin fiber 30: Wound body 40: Incised body 50: Polyrotaxane 51: Cyclic molecule 52: First polymer 53 : Blocking group 60 : Second polymer 90 : Flat plate 100 : Electronic circuit board 101 : Insulating layer (intermediate layer)
102: insulating layer (surface layer)
110: substrate 110a: one side 110b: the other side 111: through hole 120: power semiconductor element 121: solder 130: cooling unit 131: screw 140: component 150: component 160: heat spreader 210: semiconductor device 211: substrate ( support)
211a: first surface 211b: second surface 212a: solder layer 213: heat spreader 214: copper inlay (columnar body)
215: insulating layer 216: heat sink 220: heat dissipation structure AA': cutting line BB': cutting line CC': cutting line DD': cutting line FG: flake graphite _e10 : extending direction g ₁₀ : Gap M10 : Kiss coater M11 : Coating roll M12 : Liquid receiving pan M13 : Squeegee M14 : Guide roll R1 : Original fabric roll R2 : Winding roll t ₁₀ : Thickness t ₂₀ : Thickness T1 : Thickness T2 : Length T ₃ : Thickness V1 : Normal direction w ₁₀ : Width θ1 : Angle θ2 : Angle

Claims (25)

a substrate in which through holes are formed;
and a flexible thermal conductor inserted into the through hole,
The electronic circuit board, wherein the thermal conductor is in contact with different members on both sides of the through-hole in the depth direction. The thermal conductor has a compressibility of 4.0% or more and 10.0% or less when the thermal conductor is compressed with a stress of 0.25 MPa at 20° C. in the direction corresponding to the direction of insertion into the through hole. 2. The electronic circuit board of claim 1, comprising: The thermal conductor has a compressibility of 7.0% or more and 20.0% or less when the thermal conductor is compressed with a stress of 0.50 MPa at 20° C. in the direction corresponding to the direction of insertion into the through hole. 3. The electronic circuit board according to claim 1 or 2. 4. The electronic circuit board according to claim 1, wherein said thermal conductor has anisotropic thermal conductivity. 5. The electronic circuit board according to claim 4, wherein said thermal conductor has a higher thermal conductivity in the thickness direction of said substrate than in a predetermined in-plane direction of said substrate. When the predetermined in-plane direction of the substrate is the Y-axis direction, and the predetermined in-plane direction of the substrate is the X-axis direction, and the direction perpendicular to the Y-axis direction is the X-axis direction, 6. The electronic circuit board according to claim 4, wherein the thermal conductivity in the Y-axis direction is lower than the thermal conductivity in the X-axis direction. On the Y-axis direction extension of the portion of the substrate provided with the thermal conductor, there are more parts arranged on the X-axis direction extension of the portion of the substrate provided with the thermal conductor. 7. An electronic circuit board according to claim 6, on which heat sensitive components are arranged. The electronic circuit board according to any one of claims 1 to 7, wherein the heat conductor is made of a material containing resin. The resin is a polyrotaxane having a cyclic molecule, a first polymer having a linear molecular structure and including the cyclic molecule in a skewed manner, and blocking groups provided near both ends of the first polymer. , and a second polymer, wherein the polyrotaxane and the second polymer are bonded via the cyclic molecule. The electronic circuit board according to any one of claims 1 to 9, wherein the heat conductor is made of a material containing a carbon material. 11. The electronic circuit board according to claim 10, wherein said carbon material is graphite. 12. The electronic circuit board according to claim 11, wherein the graphite is flake graphite. The heat conductor according to any one of claims 1 to 12, wherein the heat conductor comprises a plurality of heat conducting parts and a joint part that is made of a flexible material and joins the heat conducting parts. Electronic circuit board as described. 14. The electronic circuit board according to claim 13, wherein at least some of the plurality of heat conducting parts are provided continuously inside the heat conductor and are exposed on both sides. 15. The electronic circuit board according to claim 13 or 14, wherein said heat-conducting portion is composed substantially of a single component. 16. The electronic circuit board according to any one of claims 13 to 15, wherein the heat conductive portion accounts for 15% by volume or more and 80% by volume or less in the heat conductor. 17. The electronic circuit board according to any one of claims 13 to 16, wherein the proportion of said joint portion in said heat conductor is 15% by volume or more and 70% by volume or less. 18. The thermal conductor according to any one of claims 13 to 17, wherein in addition to the thermal conduction part and the joint part, the thermal conductor has a gap where the thermal conduction part and the joint part do not exist. Electronic circuit board as described. Assuming that the thickness of the substrate at the portion where the through hole is provided is T1 [mm] and the length of the thermal conductor in the natural state in the thickness direction of the substrate is T2 [mm], 0. 19. The electronic circuit board according to claim 1, which satisfies the relationship 70≦T1/T2≦0.99. The electronic circuit board according to any one of claims 1 to 19, wherein the length of the heat conductor in the natural state in the thickness direction of the board is 1.0 mm or more and 6.0 mm or less. The electronic circuit board according to any one of claims 1 to 20, wherein the board is a laminated board. The electronic circuit as claimed in any one of the preceding claims, wherein the thermal conductor contacts the power semiconductor device on one side of the substrate and the cooling unit on the other side of the substrate. substrate. the power semiconductor element is soldered to the substrate,
23. The electronic circuit board according to claim 22, wherein said cooling unit is fixed on said board by screwing. S1 [mm ² ] is the sum of the areas of the top surface and the bottom surface of the heat conductor in a natural state when one surface of the two surfaces is the top surface and the other surface is the bottom surface of the heat conductor, 24. The heat conductor according to any one of claims 1 to 23, satisfying a relationship of 0.2≦S1/S2≦10.0, where S2 [mm ² ] is the side surface area of the heat conductor in its natural state. electronic circuit board. preparing a substrate having through holes;
a step of joining and soldering an electronic component to the portion of the substrate provided with the through hole;
inserting a flexible thermal conductor into the through-hole;
and fixing a cooling unit to a surface of the substrate opposite to the surface on which the electronic components are provided so as to be in contact with the heat conductor.

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