Thermal conductor and method for manufacturing thermal conductor

Abstract

The heat conductor of the present invention comprises a plurality of heat conducting parts and a joint part made of a flexible material and joining the heat conducting parts; the heat conductor has a gap part in which neither the heat conducting part nor the joint part exists; the area of ​​the heat conductor when viewed from above in the first direction is 80 [cm 2 ], and the area of ​​the heat conductor when viewed from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2 ], the thermal conductor satisfies the condition of 0.5≤[(S1-S0) / S0]×100≤20. According to the present invention, a thermal conductor can be provided that can simultaneously ensure close adhesion to a contacting member during use and suppress excessive deformation during compression.

Description

Technical Field

[0001] The present invention relates to a heat conductor and a method for manufacturing the heat conductor. Background Art

[0002] In recent years, heat dissipation measures for heat-generating components such as electronic devices, automotive headlights, and onboard batteries have become a pressing issue. For example, the miniaturization and high integration of electronic components such as central processing units (CPUs) in computers, image processing processors, SoCs (System-On-Chip) in smartphones, DSPs or microcomputers embedded in devices, as well as semiconductor elements such as transistors, light-emitting diodes (LEDs), electroluminescent devices, and liquid crystals have led to a trend of increasing heat generation. Since the heat generated by these electronic components has led to problems such as shortened device or system lifespans and malfunctions, the demand for heat dissipation measures for electronic components has been increasing year by year.

[0003] As a countermeasure for high-temperature components such as these heat-generating components, in addition to forced cooling using air cooling fans, heat-dissipating components such as metal fins or Peltier elements are also used. In order to prevent the formation of an air layer that forms a heat-insulating layer at the interface of such heat-dissipating components, grease is applied. However, general grease has low thermal conductivity. Therefore, diamond grease, which is dispersed with diamonds having relatively high thermal conductivity, is also used (for example, see Patent Document 1).

[0004] However, diamond grease is expensive, and even when diamond grease is used, it is difficult to obtain sufficient thermal conductivity.

[0005] Furthermore, when a heat conductor is placed between a high-temperature component and a heat dissipation component in electronic components such as those described above, it is sometimes placed in a compressed state with pressure applied. This improves the adhesion of the heat conductor to the high-temperature component and the heat dissipation component, maintaining low interfacial thermal resistance and significantly increasing the actual thermal conductivity.

[0006] In order to improve the adhesion of the thermal conductor to the high-temperature component and the heat dissipation component, it is more preferable that the thermal conductor be made of a relatively soft material.

[0007] However, if the thermal conductor is too soft, it may be excessively deformed when pressed, and the protruding portion may contact the exposed wiring, causing an electrical short circuit in the wiring.

[0008] If the heat conductor is made of a relatively hard material, it will rarely deform even when pressed. Although this prevents the short circuit problem caused by the protruding portion as described above, it is difficult to ensure that the heat conductor has excellent adhesion to high-temperature components and heat dissipation components.

[0009] [Prior art literature]

[0010] [Patent Document]

[0011] Patent Document 1: Japanese Patent Publication No. 2017-530220. Summary of the Invention

[0012] [Problems to be solved by the invention]

[0013] An object of the present invention is to provide a thermal conductor that achieves both the ability to ensure tight adhesion to a member in contact during use and the ability to suppress excessive deformation during compression; and to provide a method for efficiently manufacturing a thermal conductor that achieves both the ability to ensure tight adhesion to a member in contact during use and the ability to suppress excessive deformation during compression.

[0014] [Methods for solving the problem]

[0015] The heat conductor of the present invention comprises a plurality of heat conducting parts and a joint part made of a flexible material and joining the heat conducting parts; the heat conductor has a gap part in which the heat conducting parts and the joint part do not exist;

[0016] The area of ​​the heat conductor when viewed from the first direction is S0 [cm 2 ], and the area of ​​the heat conductor when viewed from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2 ], the heat conductor satisfies the condition of 0.5≤[(S1–S0) / S0]×100≤20.

[0017] In the present invention, it is more preferred that the heat conductor be in a sheet shape.

[0018] In the present invention, it is more preferred that the thickness of the heat conductor is greater than or equal to 0.15 mm and less than or equal to 20 mm.

[0019] In the present invention, it is more preferred that at least a portion of the plurality of heat conducting portions is continuously provided inside the heat conductor and exposed on two different surfaces of the heat conductor.

[0020] In the present invention, it is preferred that: the heat conductor has at least one set of parallel surfaces;

[0021] At least a portion of the plurality of heat conducting portions is a through heat conducting portion, which is continuously arranged inside the heat conducting body and exposed on the two parallel surfaces;

[0022] An angle formed between a normal direction of the surface and an extending direction of the through-heat conducting portion is greater than or equal to 3° and less than or equal to 45°.

[0023] In the present invention, it is more preferred that the ratio of the heat conducting portion in the heat conductor is greater than or equal to 15 volume % and less than or equal to 80 volume %.

[0024] In the present invention, it is more preferred that the ratio of the joining portion in the thermal conductor is greater than or equal to 15 volume % and less than or equal to 70 volume %.

[0025] In the present invention, it is more preferred that the ratio of the voids in the thermal conductor is greater than or equal to 5 volume % and less than or equal to 65 volume %.

[0026] In the present invention, it is more preferred that, when the ratio of the heat conducting portion in the heat conducting body is VC [volume %], the ratio of the joint portion in the heat conducting body is VJ [volume %], and the ratio of the void portion in the heat conducting body is VV [volume %], the heat conducting body satisfies the relationship 25 ≤ [(VJ + VV) / (VC + VJ + VV)] × 100 ≤ 90.

[0027] In the present invention, it is more preferred that the heat conducting portion is made of a material containing graphite.

[0028] In the present invention, it is more preferred that the heat conducting portion is substantially composed of a single component.

[0029] In the present invention, it is more preferred that the plurality of heat conducting portions are provided in an island shape when viewed from above in the first direction.

[0030] In the present invention, it is more preferred that the plurality of heat conducting portions are arranged in a staggered manner when viewed in plan from the first direction.

[0031] In the present invention, it is more preferred that the interval between adjacent heat conducting portions when viewed in plan from the first direction is greater than or equal to 1 μm and less than or equal to 2000 μm.

[0032] In the present invention, it is more preferable that the density of the heat conductor before the pressing state is greater than or equal to 0.6 g / cm 3 and less than or equal to 2.5g / cm 3 .

[0033] In the present invention, it is more preferable that the area of ​​the heat conductor when viewed from a second direction perpendicular to the first direction is S3 [cm 2 ],

[0034] The area of ​​the heat conductor when viewed from the second direction in the pressed state at 0.2 MPa from the first direction is set to S4 [cm 2 ], the heat conductor satisfies the condition of 5≤[(S3–S4) / S3]×100≤50.

[0035] In the present invention, it is more preferred that, when the length of the heat conductor in the initial state in the first direction is defined as L0 [mm], and the length of the heat conductor in the first direction after 1000 repetitions of pressing at 1.0 MPa in the first direction for one minute, releasing the pressing state, and allowing the heat conductor to stand for one minute is defined as L1 [mm], the heat conductor satisfies the relationship 0.70 ≤ L1 / L0.

[0036] In the present invention, it is more preferred that a measured value of the thermal conductivity in the first direction in a pressed state when pressed at 0.2 MPa from the first direction is greater than or equal to 50 W / (m·K).

[0037] A method for manufacturing a heat conductor according to the present invention includes:

[0038] a heat conducting portion forming member preparing step of preparing a heat conducting portion forming member for forming the heat conducting portion; and

[0039] a bonding portion forming composition attaching step of attaching the bonding portion forming composition used for forming the bonding portion to the surface of the heat conducting portion forming member;

[0040] The heat conductor has a gap portion, in which the heat conducting portion and the joint portion do not exist;

[0041] The area of ​​the heat conductor when viewed from the first direction is S0 [cm 2 ], and the area of ​​the heat conductor when viewed from above from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2 ], the thermal conductor manufactured by the manufacturing method satisfies the condition of 0.5≤[(S1−S0) / S0]×100≤20.

[0042] In the present invention, it is more preferable that, in the bonding portion forming composition attaching step, air bubbles are contained between the heat conduction portion forming member and the bonding portion forming composition.

[0043] A method for manufacturing a heat conductor according to the present invention includes:

[0044] a heat conducting portion forming member preparation step of preparing a long heat conducting portion forming member for forming the heat conducting portion;

[0045] a bonding portion forming composition attaching step of attaching the bonding portion forming composition used for forming the bonding portion to the surface of the heat conducting portion forming member;

[0046] a winding step of winding the heat conducting portion forming member to which the bonding portion forming composition is attached around the circumference of a reel in a traverse winding manner to obtain a cylindrical wound body; and

[0047] The slitting step is to slit the wound body in a direction that is not perpendicular to the axial direction of the roll to obtain a slit body.

[0048] In the present invention, it is more preferable that the heat conduction portion forming member is formed in a belt shape having projections and depressions on a main surface.

[0049] In the present invention, it is more preferable that the heat conduction portion forming member includes a fiber bundle extending along the longitudinal direction of the heat conduction portion forming member.

[0050] In the present invention, it is more preferred that in the winding step, a plurality of the heat conduction portion forming members to which the bonding portion forming composition is attached are wound around the circumference of one roll to obtain a single wound body.

[0051] In the present invention, it is more preferred that: the aforementioned bonding portion forming composition is a composition containing a curable resin material;

[0052] The manufacturing method further includes a curing step after the cutting step, wherein the curing step cures the curable resin material contained in the cut body.

[0053] In the present invention, it is more preferred that the curable resin material is a material that generates gas during the curing step.

[0054] [Effects of the Invention]

[0055] According to the present invention, a heat conductor can be provided that can both ensure tight adhesion to a contact member during use and suppress excessive deformation during compression, and a method for manufacturing a heat conductor can be provided that can efficiently manufacture a heat conductor that can both ensure tight adhesion to a contact member during use and suppress excessive deformation during compression. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1This is a perspective view schematically showing an example of the heat conductor of the present invention.

[0057] Figure 2 for Figure 1 A longitudinal sectional view of the heat conductor shown.

[0058] Figure 3 The side view and top view schematically show the heat conductor in its natural state.

[0059] Figure 4 The figure schematically shows a side view and a top view of the heat conductor when it is pressed from the first direction.

[0060] Figure 5 This is a perspective view schematically showing another example of the heat conductor of the present invention.

[0061] Figure 6 This is a conceptual diagram of an example of a resin material constituting a joint.

[0062] Figure 7 This is a cross-sectional view schematically showing a heat conduction portion forming member made of flaky graphite.

[0063] Figure 8 This is a diagram schematically showing an example of an apparatus used in the bonding portion forming composition attachment step and the winding step.

[0064] Figure 9 This is a diagram showing a state in which the heat conduction portion forming member is wound around the surface of the roll in a traverse winding method in the winding step.

[0065] Figure 10 A diagram schematically showing the cut body obtained in the cutting step.

[0066] Figure 11 This figure schematically shows a state in which the incised body is pressed to further improve the flatness of the incised body.

[0067] Figure 12 A diagram schematically showing the slicing step.

[0068] Figure 13 For schematic display Figure 5 FIG. 1 is a diagram showing an example of a usage mode of a heat conductor shown.

[0069] Figure 14 For schematic display Figure 5 FIG. 1 is a diagram showing an example of a usage mode of a heat conductor shown.

[0070] Figure 15 For schematic display Figure 1 FIG. 1 is a diagram showing an example of a usage mode of a heat conductor shown.

[0071] Figure 16 For schematic display Figure 1 FIG. 1 is a diagram showing an example of a usage mode of a heat conductor shown. DETAILED DESCRIPTION

[0072] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0073] [1] Heat conductor

[0074] First, the heat conductor according to the present invention will be described.

[0075] Figure 1 This is a perspective view schematically showing an example of the heat conductor of the present invention. Figure 2 for Figure 1 A longitudinal sectional view of the heat conductor shown in FIG. Figure 2 Part (a) is from Figure 1 The cross-sectional view viewed along the cutting line AA' is shown. Figure 2 Part (b) is from Figure 1 A cross-sectional view taken along cutting line BB' is shown. Figure 3 The side view and top view schematically show the heat conductor in its natural state. Figure 3 Part (a) is a side view viewed from a first direction, Figure 3 Part (b) is a top view viewed from the second direction. Figure 4 Schematically showing a side view and a top view of a state where the heat conductor is pressed from a first direction. Figure 4 Part (a) is a side view viewed from a first direction, Figure 4 Part (b) is a top view viewed from the second direction. Figure 5 This is a perspective view schematically showing another example of the heat conductor of the present invention. Figure 6 This is a conceptual diagram of an example of a resin material constituting a joint.

[0076] In this specification, the term "natural state" refers to a state in which no external forces other than gravity are applied. Specifically, it refers to a state in which no external forces other than gravity have been applied within 24 hours. Furthermore, it is preferred that the thermal conductor has not been subjected to stresses of 0.1 MPa or greater after manufacture.

[0077] In the drawings referred to in this specification, some components may be shown in reduced or enlarged form to facilitate understanding of the relationship between the components, and the size ratios between the components shown in the drawings do not necessarily represent the actual size ratios between the components.

[0078] In addition, the measurements and treatments described in this specification were performed at 20° C. unless the temperature conditions are particularly indicated.

[0079] As will be described in detail later, the heat conductor 1 has excellent heat conductivity in a predetermined direction and is used by, for example, bringing a member to be cooled into contact with the heat conductor 1 .

[0080] like Figure 1 、 Figure 2 As shown, the heat conductor 1 includes a plurality of heat conducting parts 10 and a joint part 20. The joint part 20 is made of a flexible material and joins the heat conducting parts 10. The heat conductor 1 has a gap 2 where neither the heat conducting parts 10 nor the joint part 20 exist.

[0081] Then, if Figure 3 、 Figure 4 As shown, the area of ​​the heat conductor 1 when viewed from the first direction is S0 [cm 2 ], and the area of ​​the heat conductor 1 when viewed from the first direction in a pressed state at 0.2 MPa from the first direction is defined as S1 [cm 2 ], the heat conductor 1 of the present invention satisfies the condition of 0.5≤[(S1−S0) / S0]×100≤20.

[0082] In the present invention, the "first direction" is an arbitrary direction, but in the following description, the first direction is Figure 1 The following description will focus on the up and down directions of Figure 1 The direction from the bottom to the top is the Z direction. In addition, the second direction is an arbitrary direction orthogonal to the first direction and includes Figure 1 The X and Y directions are shown. In the following description, the normal direction of the plane with the largest area among the planes of the heat conductor is used as the first direction. When pressing from the top surface of the heat conductor 1, S0 and S1 represent the area of ​​the heat conductor 1 as viewed from the top surface. S1', described below, also represents the area of ​​the heat conductor 1 as viewed from the top surface. Furthermore, when pressing from the top surface of the heat conductor 1, S3 and S4, described below, represent the area of ​​the heat conductor 1 as viewed from the side. Furthermore, when the first direction is the vertical direction, L0 and L1, described below, represent the height (thickness) of the heat conductor 1.

[0083] In addition, Figure 3 、 Figure 4 The heat conducting portion 10 and the joint portion 20 of the heat conducting body 1 are omitted. Figure 13 、 Figure 14 In addition, a predetermined pressing jig is used to press the heat conductor 1, for example, two flat plates, but Figure 4 The display of these is also omitted.

[0084] like Figure 3 、 Figure 4As shown, when heat conductor 1 is pressed from a first direction, it deforms. In other words, the height of heat conductor 1 decreases due to the pressure, and it expands in the planar directions (X and Y directions) accordingly, resulting in a so-called squeezed state. In other words, when viewed from above from the first direction, the area S1 of heat conductor 1 in the pressed state is larger than the area S0 of heat conductor 1 in its natural state.

[0085] In the measurement described in this specification, when the thermal conductor is pressed from the first direction, the pressing is performed by the flat surface of the pressing member which is larger than the size of the thermal conductor to be measured (more specifically, the area when viewed from above from the first direction) even in the pressed state.

[0086] In addition, when the surface of the heat conductor 1 to be measured whose normal is the first direction is a 40 mm × 40 mm square or a surface of a size including the square, the values ​​of S0 and S1 can be measured in a state where the size and shape of the cuboid are adjusted so that the surface whose normal is the first direction becomes a 40 mm × 40 mm square.

[0087] In the following description, a value of “[(S1−S0) / S0]×100” is defined as a “protrusion amount”.

[0088] By setting the protrusion amount within the aforementioned range, a thermal conductor can be provided that simultaneously ensures tight adhesion to contacting components during use and suppresses excessive deformation during compression. Specifically, the thermal conductor 1 has appropriate flexibility, and excessive deformation caused by compression of the thermal conductor 1 can be suppressed. For example, when the thermal conductor 1 is compressed, the protrusion is effectively prevented from unintentionally contacting other components such as electronic parts and wiring. Furthermore, tight adhesion to the component to which the thermal conductor 1 is applied (such as the component to be cooled) can be improved, and substantial heat conductivity between the component and the thermal conductor 1 can be improved. Consequently, for example, short circuits and other problems can be effectively prevented, while the component to which the thermal conductor 1 is applied can be effectively cooled.

[0089] In particular, the thermal conductor 1 of the present invention includes a void portion 2, which is free of the thermal conductive portion 10 and the joint portion 20. This void portion 2 acts as a buffer, absorbing deformation of the thermal conductor 1 when pressed (particularly deformation of the joint portion 20), thereby suppressing excessive deformation of the thermal conductor 1 as a whole. Furthermore, the thermal conductor 1 can be given appropriate flexibility, and the amount of protrusion can be appropriately adjusted to meet the aforementioned conditions.

[0090] On the other hand, if the above conditions are not met, satisfactory results cannot be obtained. For example, if the heat conductor does not have a gap, the deformation of the heat conductor when pressed cannot be absorbed, and the amount of protrusion when pressing the heat conductor will increase, which cannot fully prevent the above-mentioned problems.

[0091] On the other hand, if the value of [(S1−S0) / S0]×100 is less than the aforementioned lower limit, the flexibility of the thermal conductor is insufficient, and sufficient adhesion to a member to which the thermal conductor is applied cannot be obtained.

[0092] On the other hand, if the value of [(S1−S0) / S0]×100 exceeds the upper limit, the heat conductor may be excessively deformed when pressed, and thus the heat conductor may contact an unintended location, which may easily cause problems such as a short circuit.

[0093] As described above, the heat conductor 1 of the present invention satisfies the condition of 0.5 ≤ [(S1 − S0) / S0] × 100 ≤ 20, more preferably satisfies the condition of 1.0 ≤ [(S1 − S0) / S0] × 100 ≤ 15, further preferably satisfies the condition of 1.5 ≤ [(S1 − S0) / S0] × 100 ≤ 10, and particularly preferably satisfies the condition of 2.0 ≤ [(S1 − S0) / S0] × 100 ≤ 8.0.

[0094] According to this, the effects produced by the above-mentioned present invention are more significantly exerted.

[0095] In the heat conductor 1, for example, the protrusion amount can be appropriately adjusted by appropriately adjusting the ratio of the heat conducting portion 10, the ratio of the joint portion 20, and the ratio of the gap portion 2 in the heat conductor 1, or by appropriately selecting the flexibility of the joint portion 20 (in other words, appropriately selecting the material of the joint portion 20).

[0096] The area of ​​the thermal conductor 1 when viewed from the first direction is S0 [cm 2 ], and the area of ​​the heat conductor 1 when viewed from the first direction in a pressed state with a predetermined pressure and a compression rate of 20% in the thickness direction is defined as S1' [cm 2 ], the heat conductor 1 preferably satisfies the condition of 1.0≤[(S1′–S0) / S0]×100≤15, more preferably satisfies the condition of 1.5≤[(S1′–S0) / S0]×100≤10, and particularly preferably satisfies the condition of 2.0≤[(S1′–S0) / S0]×100≤8.0.

[0097] Thereby, the above-mentioned effects of the present invention can be made more remarkable.

[0098] exist Figure 5 In the illustrated configuration, the heat conductor 1 is formed in a sheet shape.

[0099] In this way, if the heat conductor 1 is formed into a sheet, the entire heat conductor 1 can be appropriately curved. For example, the volume of the heat conductor 1 can be reduced, while also achieving particularly excellent thermal conductivity when applied to components with flat surfaces or surfaces with relatively small curvature. Furthermore, the term "flat surface" herein also encompasses surfaces with minute irregularities. Furthermore, even if the component to which the heat conductor 1 is applied has irregularities on its surface, the entire surface of the heat conductor 1 can be covered, and microscopically, the component to which the heat conductor 1 is applied can be more closely adhered to the heat conductor 1. In other words, the contact between the component to which the heat conductor 1 is applied and the heat conductor 1 in microscopic areas can be improved. Therefore, for example, when the component to which the heat conductor 1 is applied is a heat-generating component, heat dissipation can be improved. Furthermore, when the heat conductor 1 is used, even when the space for placement of the heat conductor 1 (the width between multiple components in contact with the heat conductor 1) is narrow, the heat conductor 1 can be suitably positioned.

[0100] When the heat conductor 1 is formed into a sheet, the thickness of the heat conductor 1 in the natural state, that is, Figure 5 The length indicated by T1 is preferably greater than or equal to 0.15 mm and less than or equal to 20 mm, more preferably greater than or equal to 0.20 mm and less than or equal to 10 mm, and particularly preferably greater than or equal to 0.25 mm and less than or equal to 5 mm.

[0101] This makes it possible to more appropriately follow the surface shape of a member to which the sheet-shaped heat conductor 1 is applied, and to more significantly exhibit the aforementioned effects.

[0102] exist Figure 1 In the structure shown, the heat conductor 1 is in a block shape.

[0103] As described above, in the present invention, the thermal conductor 1 is not limited to a sheet shape, and may be in any shape.

[0104] If the heat conductor 1 is in a block shape, for example, even when the component to which the heat conductor 1 is applied has a complex surface shape, the heat conductor 1 can be appropriately adhered to the component, thereby achieving particularly excellent thermal conductivity. Furthermore, since the heat conductor 1 can be appropriately adhered to the component to which the heat conductor 1 is applied in a three-dimensional manner, the heat conductor 1 can be appropriately applied even when the area to which the heat conductor 1 is applied covers a relatively wide area in the three-dimensional direction.

[0105] When the heat conductor 1 is in a block shape, the thickness of the heat conductor 1 in its natural state is, Figure 1 The length indicated by T2 is preferably greater than or equal to 30 mm and less than or equal to 200 mm, more preferably greater than or equal to 50 mm and less than or equal to 150 mm, and particularly preferably greater than or equal to 70 mm and less than or equal to 120 mm.

[0106] Such a block-shaped heat conductor 1 can be suitably used for cooling relatively large parts such as motors, for example.

[0107] In the drawings referred to in this specification, the interface between the heat conducting portion 10 and the joining portion 20 is clearly shown. However, for example, the interface between the heat conducting portion 10 and the joining portion 20 may become unclear due to a portion of the heat conducting portion 10 intruding into the joining portion 20 .

[0108] [1–1] Heat transfer unit

[0109] The plurality of heat conducting portions 10 mainly contribute to the overall heat conductivity of the heat conductor 1 (specifically, the heat conductivity in the extending direction of the heat conducting portion 10 ).

[0110] In this specification, the extending direction of the heat conducting portion forming member 10 ′ described in detail later is defined as the extending direction of the heat conducting portion 10 . For example, Figure 1 In the structure shown, the direction of the YZ plane is the extending direction of the heat conducting portion 10. Figure 7 In the figure, the lateral depth direction is the extending direction of the heat conducting portion forming member 10 ′ and the extending direction of the heat conducting portion 10 .

[0111] like Figure 1 As shown, in the heat conductor 1 , it is more preferable that the plurality of heat conducting portions 10 are provided in an island shape when viewed from above in the first direction.

[0112] This can suppress the surface of the thermal conductor 1 ( Figure 1 The unevenness of the thermal conductivity of each portion (in the direction of the XY plane shown) can be easily eliminated, and the flexibility of the thermal conductor 1 as a whole can be further improved, so that the effects of the present invention described above can be more reliably and significantly exerted.

[0113] In this specification, "island-like" means that the plurality of heat conducting portions 10 are discontinuous and exist as dots in the joint 20. In other words, the heat conducting portion 10 is independent of other heat conducting portions 10 in either the X or Y direction.

[0114] exist Figure 1 The heat conductor 1 shown has a plurality of heat conducting portions 10 arranged in a staggered pattern when viewed from a first direction. In other words, the plurality of heat conducting portions 10 are arranged in a first row 10a and a second row 10b in the Y direction, and are alternately arranged in the X direction so that the heat conducting portions 10 are arranged in a different pattern.

[0115] According to this, the above-mentioned effects can be more significantly exerted.

[0116] It is more preferable that the heat conducting parts 10 in the first row 10 a and the heat conducting parts 10 in the second row 10 b at least partially overlap in the X direction.

[0117] According to this, the above-mentioned effects can be more significantly exerted.

[0118] When looking down from the first direction Figure 1 w 10 The width of the heat conducting portion 10 is preferably greater than or equal to 1 mm and less than or equal to 30 mm, more preferably greater than or equal to 5 mm and less than or equal to 20 mm, and particularly preferably greater than or equal to 7 mm and less than or equal to 15 mm.

[0119] In addition, Figure 1 t in 10 The thickness of the heat conducting portion 10 shown is preferably greater than or equal to 5 μm and less than or equal to 500 μm, and more preferably greater than or equal to 10 μm and less than or equal to 200 μm.

[0120] This can sufficiently increase the proportion of the heat conducting portion 10 in the heat conductor 1, easily improve the flexibility of the heat conductor 1 as a whole, and more reliably and significantly exhibit the effects of the present invention.

[0121] When the heat conductor 1 is viewed from above from the first direction Figure 1 g in 10 The interval between adjacent heat conducting portions 10 shown is preferably greater than or equal to 1 μm and less than or equal to 2000 μm, more preferably greater than or equal to 2 μm and less than or equal to 1500 μm, and particularly preferably greater than or equal to 3 μm and less than or equal to 1000 μm.

[0122] According to this, the ratio of the heat conducting portion 10 in the heat conducting body 1 can be sufficiently increased, and the flexibility of the heat conducting body 1 as a whole can be further improved, and the effect of the present invention described above can be more significantly exerted. Figure 1 g in 10 The distance between adjacent heat conducting parts 10 is shown. That is, g 10 In this case, for example, adjacent heat conducting parts 10 may contact each other at their side surfaces. In addition, at least a portion of the plurality of flat heat conducting parts 10 may overlap with each other so that a portion of the heat conducting parts 10 in the width direction of the heat conducting parts 10 contacts each other.

[0123] In addition, in this specification, “the interval between adjacent heat conducting parts 10 ” means the gap which is the shortest distance between adjacent heat conducting parts 10 .

[0124] In addition, Figure 1In FIG. 1 , the plurality of heat conducting parts 10 are arranged in a staggered manner, but the plurality of heat conducting parts 10 may be arranged in a manner other than a staggered manner. The plurality of heat conducting parts 10 may be arranged regularly or randomly.

[0125] More preferably, at least a portion of the plurality of heat conducting portions 10 is continuously provided inside the heat conductor 1 (specifically, continuously provided inside the heat conductor 1 along the direction (first direction) in which the heat conductor 1 is pressed during use), and at least a portion of the plurality of heat conducting portions 10 is exposed on two different surfaces of the heat conductor (specifically, exposed on two different surfaces of the heat conductor 1 that come into contact with other components in the above-mentioned direction during use).

[0126] As a result, the substantial thermal conductivity in the aforementioned direction can be further improved.

[0127] In particular, the heat conductor 1 of the illustrated configuration has at least one set of parallel surfaces, and at least a portion of the plurality of heat conducting portions 10 is a through heat conducting portion 10c that is continuously provided inside the heat conductor 1 and exposed on two parallel surfaces.

[0128] Accordingly, the substantial heat conductivity between the two parallel surfaces can be made more excellent.

[0129] In this specification, the term "parallel" does not mean strictly "parallel" in the mathematical sense, and slight deviations are permitted.

[0130] exist Figure 1 、 Figure 2 In the heat conductor 1 shown, the through heat conducting portion 10c is Figure 2 China-Israel e 10 Display, and its extension direction is Figure 2 In other words, the extending direction of the through heat conducting portion 10c is inclined relative to the pressing direction (first direction) of the heat conductor 1 when in use.

[0131] Thus, even when a relatively large load is applied to the thermal conductor 1, irreversible deformation of the thermal conductor 1, such as collapse of the thermal conductor 1 due to buckling, can be more effectively suppressed, thereby further improving the durability of the thermal conductor 1. Furthermore, when the thermal conductor 1 is compressed in the first direction, surface pressure is easily applied to the thermal conductor 1, further improving the adhesion between the thermal conductor 1 and the component to which it is applied. Furthermore, when pressure is applied to the thermal conductor 1 in the first direction, this pressure includes a component of force that presses the thermal conductive portion 10 and the joint portion 20, further improving the adhesion between the thermal conductive portion 10 and the joint portion 20.

[0132] In addition, if Figure 2 As shown, the inclination directions of the penetrating heat conducting portions 10 c in the first row 10 a and the second row 10 b of the heat conducting portions 10 are opposite to each other with respect to the normal direction V1 of the surface.

[0133] The inclination direction of the through heat conducting portions 10c in the first row 10a relative to the surface normal direction V1 is defined as a positive (+) direction, and the inclination direction of the through heat conducting portions 10c in the second row 10b relative to the surface normal direction is defined as a negative (−) direction.

[0134] That is, the through-heat conductive portions 10c of the first row 10a are tilted in the positive direction by θ1 relative to the surface normal direction V1, and the through-heat conductive portions 10c of the second row 10b are tilted in the negative direction by θ2 relative to the surface normal direction V1.

[0135] By providing the through-heat conductive portions 10c inclined in mutually different directions (specifically, the through-heat conductive portions 10c inclined in the positive direction relative to the surface normal direction V1 and the through-heat conductive portions 10c inclined in the negative direction relative to the surface normal direction V1), for example, even when a relatively large load is applied to the heat conductive element 1, irreversible deformation of the heat conductive element 1, such as collapse due to buckling, can be more effectively suppressed, thereby enhancing the durability of the heat conductive element 1. Furthermore, when the heat conductive element 1 is compressed in the first direction, surface pressure is more easily applied to the heat conductive element 1, further improving the adhesion between the heat conductive element 1 and the member to which it is applied. Furthermore, when pressure is applied to the heat conductive element 1 in the first direction, this pressure includes a component of force that presses the heat conductive portion 10 against the joint 20, further improving the adhesion between the heat conductive portion 10 and the joint 20.

[0136] In particular, by alternately arranging the through heat conducting portions 10 c tilted in the positive direction relative to the surface normal direction V1 and the through heat conducting portions 10 c tilted in the negative direction relative to the surface normal direction V1 , the aforementioned effects can be more significantly exhibited.

[0137] like Figure 2 As shown, the normal direction V1 of the surface and the extending direction e of the penetrating heat conducting portion 10c are 10 The absolute values ​​of the formed angles θ1 and θ2 are preferably greater than or equal to 3° and less than or equal to 45°, more preferably greater than or equal to 5° and less than or equal to 40°, and particularly preferably greater than or equal to 8° and less than or equal to 35°.

[0138] Thus, when the heat conductor 1 is compressed in the first direction, surface pressure is easily applied to the heat conductor 1, further improving the adhesion between the heat conductor 1 and the member to which the heat conductor 1 is applied. Furthermore, when pressure is applied to the heat conductor 1 in the first direction, this pressure includes a component of force that presses the heat conductive portion 10 and the joint portion 20, thereby further improving the adhesion between the heat conductive portion 10 and the joint portion 20.

[0139] In addition, the angle θ1 and the angle θ2 may be different in size, but are preferably the same.

[0140] The angles are not mathematically precise values ​​and may include common errors in the technical field of the present invention. For example, a difference of less than 1° is interpreted as an error and is considered the same angle.

[0141] The inclination direction of the heat conducting portion 10 is not particularly limited. However, when the heat conducting portion 10 (the heat conducting portion forming member 10 ′) is in a strip shape, it is preferable that the surface direction of the heat conducting portion 10 is inclined relative to the normal direction V1 of the surface.

[0142] Thus, for example, even when a relatively large load is applied to the thermal conductor 1, irreversible deformation of the thermal conductor 1, such as collapse of the thermal conductor 1 due to buckling, can be more effectively suppressed, thereby further improving the durability of the thermal conductor 1. Furthermore, when the thermal conductor 1 is compressed in the first direction, surface pressure is easily applied to the thermal conductor 1, further improving the adhesion between the thermal conductor 1 and the component to which it is applied. Furthermore, when pressure is applied to the thermal conductor 1 in the first direction, this pressure includes a force component that presses the thermal conductive portion 10 and the joint portion 20, thereby further improving the adhesion between the thermal conductive portion 10 and the joint portion 20.

[0143] The heat conducting portion 10 is not particularly limited as long as it has thermal conductivity. However, materials constituting the heat conducting portion 10 include, for example, ceramic materials such as aluminum nitride, boron nitride, silicon nitride, silicon carbide, and alumina; carbon materials such as graphite and carbon fiber; and metal materials such as copper and aluminum. Preferably, the heat conducting portion 10 is made of a carbon material, and more preferably, it is made of a material containing graphite.

[0144] Thus, the actual thermal conductivity between the member to which the thermal conductor 1 is applied and the thermal conductor 1 can be further improved, while the manufacturing cost of the thermal conductor 1 can be reduced.

[0145] [1–1–1] Carbon materials

[0146] In particular, if the heat conducting portion 10 is formed from a heat conducting portion-forming member 10' comprising a carbon material such as graphite or carbon fiber, in addition to the aforementioned effects, the following effects can be achieved. Specifically, the flexibility and softness of the heat conducting member 1 can be enhanced. For example, the heat conducting member 1 can have a greater resilience when bent. Furthermore, the cushioning properties created by internal voids and the improved contact properties with components to which the heat conducting member 1 is applied can be enhanced due to moderate deformation during contact. These effects are particularly pronounced when graphite is used as the carbon material.

[0147] [1–1–2] Metal materials

[0148] Furthermore, if the heat conducting portion 10 is formed using a heat conducting portion forming member 10' made of a metal material, in addition to the aforementioned effects, the following effects can be achieved. Specifically, the strength of the bonding force within the metal material can further reduce the dust generation of the heat conducting member 1. Furthermore, even when a relatively large load is applied to the heat conducting member 1, irreversible deformation of the heat conducting member 1, such as collapse due to buckling, can be more effectively prevented.

[0149] The metal material constituting the heat conducting portion 10 includes various metals or alloys, and one or more metals can be selected from these or used in combination. It is more preferred to include one or more metals selected from the group consisting of Al, Cu, Ag, Au, Mg, and Zn.

[0150] This makes it possible to further improve the thermal conductivity of the heat conducting portion 10 .

[0151] Examples of alloys containing the metal elements constituting the aforementioned group include Duralumin, an aluminum alloy containing Al, Cu, and Mg.

[0152] It is more preferable that the heat conducting portion 10 is substantially composed of a single component.

[0153] This can further improve the thermal conductivity of the heat conducting portion 10. In addition, it is generally advantageous in reducing the manufacturing cost of the heat conductor 1.

[0154] Furthermore, the phrase "substantially composed of a single component" means that the proportion of the main component in the target portion is 95% by weight or greater. The proportion of the main component is more preferably 97% by weight or greater, and even more preferably 99% by weight or greater.

[0155] However, if the heat conducting portion 10 contains a gas such as air, the content of this gas is assumed to be negligible. Furthermore, if the heat conducting portion 10 is made of a metal material, an oxide film of the metal constituting the heat conducting portion 10, such as a passivation film, may form on its surface. When such an oxide film is formed, it is considered to be "consisting essentially of a single component." This also applies to the heat conducting portion forming member 10', described in detail below.

[0156] The ratio of the heat conducting portion 10 in the heat conductor 1 (the ratio in the natural state; the same applies hereinafter) is preferably greater than or equal to 15 volume % and less than or equal to 80 volume %, more preferably greater than or equal to 20 volume % and less than or equal to 75 volume %, particularly preferably greater than or equal to 25 volume % and less than or equal to 70 volume %, and most preferably greater than or equal to 30 volume % and less than or equal to 65 volume %.

[0157] This can significantly increase the proportion of the heat conducting portion 10 in the heat conductor 1 and easily improve the flexibility of the heat conductor 1 as a whole, thereby more reliably and significantly achieving the effects of the present invention.

[0158] [1–2] Joint

[0159] The joint 20 is disposed between the plurality of heat conducting portions 10 (arranged in an island shape when the heat conducting body 1 is viewed from the first direction) and joins the heat conducting portions 10 together. The joint 20 is composed of a flexible resin material 21. The resin material 21 is a cured product of a curable resin material 21' described below.

[0160] The joint portion 20 is made of a flexible resin material 21 , whereby the thermal conductor 1 has excellent shape adaptability to the surface shape of a member to which the thermal conductor 1 is applied, for example, a member to be cooled.

[0161] Furthermore, the joining portion 20 is made of the flexible resin material 21 , thereby suitably preventing the thermal conductor 1 from being damaged when the thermal conductor 1 is deformed.

[0162] [1–2–1] Resin materials

[0163] The resin material 21 constituting the joint 20 is not particularly limited as long as it is flexible. Examples thereof include flexible epoxy resins, rubber resins, urethane resins, silicone resins, fluorine resins, acrylic resins, and thermoplastic elastomers. The resin material 21 is preferably Figure 6As shown, it includes a polyrotaxane 50 and a second polymer 60, and the polyrotaxane 50 is bonded to the second polymer 60 via a cyclic molecule 51. The polyrotaxane 50 has: the cyclic molecule 51, a first polymer 52 having a linear molecular structure and skewering the cyclic molecule 51, and end capping groups 53 provided near both ends of the first polymer 52.

[0164] This improves the bonding strength between the heat conducting portion 10 and the bonding portion 20 in the heat conductor 1. Furthermore, irreversible deformation of the heat conductor 1 can be more effectively suppressed when the heat conductor 1 is repeatedly pressed with a relatively large force or when pressed with a relatively large force for a long period of time, thereby improving the durability of the heat conductor 1. Furthermore, the heat conductor 1 can have particularly excellent flexibility and heat resistance.

[0165] In particular, Figure 6 When the stress in the arrow direction is applied to the resin material 21 in the state shown in part (A), the resin material 21 can be made as follows: Figure 6 The embodiment shown in part (B) of FIG. Specifically, in resin material 21, because cyclic molecules 51 can move along first polymer 52, that is, because first polymer 52 can move within cyclic molecules 51, deformation stress can be efficiently absorbed within resin material 21. Therefore, even when a large external force such as a torsional deformation force is applied, damage to joint 20 and damage to the joints between heat conducting parts 10 can be effectively prevented.

[0166] Hereinafter, the resin material 21 including the polyrotaxane 50 and the second polymer 60 will be described in detail.

[0167] The cyclic molecule 51 constituting the polyrotaxane 50 may be any cyclic molecule as long as it can move along the first polymer 52 , but is preferably a substituted cyclodextrin molecule. The cyclodextrin molecule is particularly preferably selected from the group consisting of α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, and derivatives thereof.

[0168] As described above, at least a portion of the cyclic molecules 51 in the polyrotaxane 50 is bonded to at least a portion of the second polymer 60 .

[0169] Examples of the functional groups possessed by the cyclic molecule 51 (functional groups bonded to the second polymer 60) include -OH groups, -NH2 groups, -COOH groups, epoxy groups, vinyl groups, thiol groups, and photocrosslinking groups. Examples of photocrosslinking groups include cinnamic acid, coumarin, chalcone, anthracene, styrylpyridine, styrylpyridinium salts, and styrylquinolinium salts.

[0170] When the cyclic molecules 51 are enclosed in the first polymer 52 and formed into a string, the amount of cyclic molecules 51 enclosed in the first polymer 52 and formed into a string is preferably greater than or equal to 0.001 and less than or equal to 0.6, more preferably greater than or equal to 0.01 and less than or equal to 0.5, and particularly preferably greater than or equal to 0.05 and less than or equal to 0.4. Alternatively, two or more different cyclic molecules 51 may be used.

[0171] Examples of the first polymer 52 constituting the polyrotaxane 50 include cellulose resins such as polyvinyl alcohol, polyvinyl pyrrolidone, poly(meth)acrylic acid, carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose; polyacrylamide, polyethylene oxide, polyethylene glycol, polypropylene glycol, polyvinyl acetal resins, polyvinyl methyl ether, polyamine, polyethyleneimine, casein, gelatin, and starch, and / or copolymers thereof; polyolefin resins such as polyethylene, polypropylene, and copolymers thereof with other olefin monomers; polyester resins; polyvinyl chloride resins; and polystyrene resins such as polystyrene or acrylonitrile-styrene copolymer resins. , polymethyl methacrylate or (meth)acrylate copolymer, acrylic resins such as acrylonitrile-methacrylate copolymer resin, polycarbonate resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, etc.; and derivatives or modified products thereof, polyisobutylene, polytetrahydrofuran, polyaniline, acrylonitrile-butadiene-styrene copolymer, polyamides such as nylon, polyimides, polyisoprene, polybutadiene and other polydienes, polysiloxanes such as polydimethylsiloxane, polysulfones, polyimines, polyacetic anhydrides, polyureas, polysulfides, polyphosphazenes, polyketones, polyphenylenes, polyhaloolefins, and derivatives thereof, especially polyethylene glycol is more preferred.

[0172] The weight average molecular weight of the first polymer 52 is preferably greater than or equal to 10,000, more preferably greater than or equal to 20,000, and particularly preferably greater than or equal to 35,000. Alternatively, two or more different first polymers 52 may be used.

[0173] The combination of the cyclic molecule 51 and the first polymer 52 is preferably such that the cyclic molecule 51 is substituted α-cyclodextrin and the first polymer 52 is polyethylene glycol.

[0174] The end-capping group 53 constituting the polyrotaxane 50 is not particularly limited as long as it is a group having the function of preventing the cyclic molecule 51 from detaching from the first polymer 52. Examples thereof include: dinitrophenyl groups, cyclodextrin groups, adamantyl groups, trityl groups, fluorescein groups, pyrene groups, substituted benzene groups (substituents include alkyl groups, alkoxy groups, hydroxyl groups, halogen groups, cyano groups, sulfonyl groups, carboxyl groups, amino groups, phenyl groups, etc. There may be one or more substituents), substituted polynuclear aromatic groups, steroids, etc.

[0175] Examples of substituents constituting substituted benzenes and substituted polynuclear aromatics include alkyl, alkoxy, hydroxy, halogen, cyano, sulfonyl, carboxyl, amino, and phenyl groups. One or more substituents may be present. Furthermore, two or more different end-capping groups 53 may be used.

[0176] In the resin material 21 , at least a portion of the polyrotaxane 50 is bonded to the second polymer 60 via the cyclic molecule 51 . However, the resin material 21 may include a polyrotaxane 50 that is not bonded to the second polymer 60 , or the polyrotaxanes 50 may be bonded to each other.

[0177] The second polymer 60 is bonded to the polyrotaxane 50 via the cyclic molecule 51. Examples of the functional group bonded to the cyclic molecule 51 of the second polymer 60 include: -OH groups, -NH2 groups, -COOH groups, epoxy groups, vinyl groups, thiol groups, and photocrosslinking groups. Examples of photocrosslinking groups include: cinnamic acid, coumarin, chalcone, anthracene, styrylpyridine, styrylpyridinium salts, and styrylquinolinium salts.

[0178] Examples of the second polymer 60 include polyvinyl alcohol, polyvinyl pyrrolidone, poly(meth)acrylic acid, cellulose resins such as carboxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose, polyacrylamide, polyethylene oxide, polyethylene glycol, polypropylene glycol, polyvinyl acetal resins, polyvinyl methyl ether, polyamine, polyethyleneimine, casein, gelatin, starch, and / or copolymers thereof, polyolefin resins such as polyethylene, polypropylene, and copolymers thereof with other olefin monomers, polyester resins, polyvinyl chloride resins, polystyrene resins such as polystyrene or acrylonitrile-styrene copolymer resins, polymethyl methacrylate or (meth)acrylic acid. Acrylic resins such as acrylate copolymers, acrylonitrile-methacrylate copolymer resins, polycarbonate resins, polyurethane resins, vinyl chloride-vinyl acetate copolymer resins, polyvinyl butyral resins, and derivatives or modified products thereof, polyisobutylene, polytetramethylene ether, polyaniline, acrylonitrile-butadiene-styrene copolymers, polyamides such as nylon, polyimides, polyisoprene, polydienes such as polybutadiene, polysiloxanes such as polydimethylsiloxane, polysulfones, polyimines, polyacetic anhydrides, polyureas, polysulfides, polyphosphazenes, polyketones, polyphenylenes, and polyhaloolefins, and having the aforementioned functional groups.

[0179] In addition, the second polymer 60 and the cyclic molecule 51 may be chemically bonded via a cross-linking agent.

[0180] The molecular weight of the cross-linking agent is more preferably less than 2000, more preferably less than 1000, particularly preferably less than 600, and most preferably less than 400.

[0181] Examples of the crosslinking agent include cyanuric chloride, trimesoyl chloride, terephthaloyl chloride, epichlorohydrin, dibromobenzene, glutaraldehyde, phenylene diisocyanate, tolylene diisocyanate, divinyl sulfone, 1,1'-carbonyldiimidazole, and alkoxysilanes. Two or more different crosslinking agents may be used.

[0182] The second polymer 60 may be a homopolymer or a copolymer. In the resin material 21, at least a portion of the second polymer 60 is bonded to the polyrotaxane 50 via the cyclic molecule 51. However, the resin material 21 may also contain a second polymer 60 that is not bonded to the polyrotaxane 50, or the second polymers 60 may be bonded to each other. Furthermore, two or more different second polymers 60 may be used.

[0183] In the resin material 21 , the content ratio of the polyrotaxane 50 to the content of the second polymer 60 is preferably 1 / 1000 or more in terms of weight ratio.

[0184] [1–2–2] Other ingredients

[0185] The bonding portion 20 may contain components other than the resin material.

[0186] Examples of such ingredients include metal particles, ceramic particles, spacers, fibrous base materials such as non-woven fabrics and woven fabrics, plasticizers, colorants, antioxidants, ultraviolet absorbers, light stabilizers, softeners, modifiers, rust inhibitors, fillers, electromagnetic wave absorbers such as granulated iron, surface lubricants, corrosion inhibitors, heat stabilizers, lubricants, primers, antistatic agents, polymerization inhibitors, crosslinking agents, catalysts, leveling agents, thickeners, dispersants, anti-aging agents, flame retardants, anti-hydrolysis agents, and corrosion inhibitors.

[0187] If the joint portion 20 includes metal particles, the following effects can be obtained.

[0188] That is, as mentioned above, the portion that primarily contributes to the thermal conductivity of the heat conductor 1 is the heat conducting portion 10. However, metal particles generally have a higher thermal conductivity than the resin material 21 constituting the joint 20. Therefore, by including metal particles in the joint 20, the thermal conductivity of the joint 20 can be improved, thereby further improving the thermal conductivity of the heat conductor 1 as a whole.

[0189] In particular, when one or more metal particles contained in the joint portion 20 connect adjacent heat conducting portions 10 , the metal particles form a “heat path” that thermally connects the heat conducting portions 10 , thereby further improving the thermal conductivity of the entire heat conductor 1 .

[0190] Furthermore, by including metal particles made of a metal material having electromagnetic wave shielding properties, an electromagnetic wave shielding function can be imparted to the thermal conductor 1. In particular, for example, a shielding function against high-frequency electromagnetic waves used in fifth-generation mobile communications can be preferably imparted.

[0191] The metal particles preferably contain one or more selected from the group consisting of Fe, Ag, Pt, Cu, Sn, Al, and Ni, and more preferably contain Fe.

[0192] The shape of the metal particles is not particularly limited, but is preferably spherical, and more preferably true spherical.

[0193] This can make the above-mentioned effects more significant.

[0194] More specifically, the shape factor SF-2 of the metal particles is preferably greater than or equal to 100 and less than or equal to 150, more preferably greater than or equal to 100 and less than or equal to 125, and particularly preferably greater than or equal to 100 and less than or equal to 120.

[0195] The shape factor SF–2 is the value obtained by dividing the square of the length of the particle's projected perimeter by the particle's projected area, dividing that value by 4π, and multiplying the result by 100. The closer the particle's shape is to a sphere, the closer the value is to 100.

[0196] The shape factor SF-2 can be obtained, for example, by the following measurement.

[0197] That is, for example, under observation using FE-SEM, the projected area S [μm 2 ] and the projected circumference L [μm], and the value calculated from the following formula is used as the shape factor SF-2. Next, the average value of the shape factors SF-2 for each metal particle is used as the shape factor SF-2 of the metal particle.

[0198] SF–2=((L 2 / S) / 4π)×100

[0199] The average particle size of the metal particles is not particularly limited, but is preferably greater than or equal to 0.01 μm and less than or equal to 10 μm, and more preferably greater than or equal to 0.1 μm and less than or equal to 3.0 μm.

[0200] This can make the above-mentioned effects more significant.

[0201] In this specification, the average particle size refers to the particle size at which the cumulative value from the smaller diameter side reaches 50% in the weight-based particle size distribution measured by a laser diffraction particle size distribution analyzer.

[0202] The metal particles are preferably iron particles.

[0203] Examples of the iron particles include iron particles produced by thermally decomposing Fe(CO) 5 .

[0204] Such iron particles are of very high purity, have a true spherical shape as described above, and have a very small average particle size, so the above-mentioned effects can be particularly pronounced.

[0205] When the joint 20 contains metal particles, the content of the metal particles in the joint 20 (the content in the natural state) is preferably greater than or equal to 1 volume % and less than or equal to 50 volume %, and more preferably greater than or equal to 10 volume % and less than or equal to 30 volume %.

[0206] Thus, the effects of including the resin material 21 and the effects of including the metal particles can be well-balanced.

[0207] If the joint 20 contains ceramic particles, the structure of the joint 20 can be stabilized and uniformed, and the ratio and size of the voids in the joint 20 can also be stabilized. As a result, unexpected variations in characteristics between different parts of the thermal conductor 1 can be more effectively prevented.

[0208] Various ceramics can be used as the constituent material of the ceramic particles. However, the use of ceramic materials such as nitride-based ceramics such as aluminum nitride, boron nitride, and silicon nitride, carbide-based ceramics such as silicon carbide, and oxide-based ceramics such as aluminum oxide can further enhance the thermal conductivity of the thermal conductor 1 as a whole. In particular, when one or more ceramic particles contained in the joint 20 connect adjacent thermally conductive sections 10, these ceramic particles serve as "heat paths" that thermally connect the thermally conductive sections 10, further enhancing the thermal conductivity of the thermal conductor 1 as a whole.

[0209] When the joint portion 20 includes the aforementioned metal particles in addition to the ceramic particles, the aforementioned heat path may also be formed by the ceramic particles and the metal particles.

[0210] Alternatively, the ceramic particles may be made of silicon dioxide, thereby reducing the production cost of the thermal conductor 1 and achieving the aforementioned effects of stabilizing and homogenizing the structure of the joint 20 .

[0211] The shape of the ceramic particles is not particularly limited, but is preferably spherical, and more preferably true spherical.

[0212] This can make the above-mentioned effects more significant.

[0213] The average particle size of the ceramic particles is not particularly limited, but is preferably greater than or equal to 5 μm and less than or equal to 200 μm, more preferably greater than or equal to 10 μm and less than or equal to 100 μm, and particularly preferably greater than or equal to 20 μm and less than or equal to 70 μm.

[0214] This can make the above-mentioned effects more significant.

[0215] The content of ceramic particles in the joint 20 (content in a natural state) is preferably greater than or equal to 1 volume % and less than or equal to 50 volume %, and more preferably greater than or equal to 10 volume % and less than or equal to 30 volume %.

[0216] Thus, the effects of the resin material 21 and the ceramic particles can be well balanced.

[0217] However, the content of components other than the resin material, metal particles, and ceramic particles in the joint portion 20 is preferably 5% by weight or less, more preferably 3% by weight or less, and particularly preferably 1% by weight or less.

[0218] If the joint 20 includes a spacer, unexpected variations in the thickness of the joint 20 can be appropriately suppressed. Furthermore, a gap 2 can be appropriately formed between the resin material 21 constituting the joint 20 and the spacer. This effect is particularly pronounced when the spacer has the size and shape described below. Furthermore, when manufacturing the thermal conductor 1, the resin material 21 constituting the joint 20 can be effectively prevented from protruding from the end. As a result, the joint 20 preferentially contacts the component to which the thermal conductor 1 is applied, effectively preventing problems with contact being hindered at the thermal conductor 10 and ensuring superior thermal conductivity.

[0219] The shape of the spacer may be, for example, a rotational ellipsoid, a cylinder, a prism, or a needle, but is preferably a spherical shape, and more preferably a true sphere.

[0220] This can more appropriately suppress unintended variations in thickness of the bonding portion 20. Furthermore, the gap 2 can be more appropriately formed between the resin material 21 constituting the bonding portion 20 and the spacer.

[0221] When the spacer is spherical, especially true spherical, the shape factor SF-2 of the spacer is preferably greater than or equal to 100 and less than or equal to 150, more preferably greater than or equal to 100 and less than or equal to 125, and particularly preferably greater than or equal to 100 and less than or equal to 120.

[0222] According to this, the aforementioned effects can be more significantly exerted.

[0223] When the spacer is spherical, especially true spherical, the average particle size of the spacer is not particularly limited, but is preferably greater than or equal to 0.1 μm and less than or equal to 100 μm, more preferably greater than or equal to 1 μm and less than or equal to 50 μm.

[0224] According to this, the aforementioned effects can be more significantly exerted.

[0225] The spacer can be made of any material, for example, metal, ceramic, glass, etc., but is preferably made of a resin material.

[0226] This makes it possible to further improve the adhesion between the spacer and the resin material 21 and further improve the durability and reliability of the thermal conductor 1 .

[0227] As for the resin material constituting the spacer, for example, polyester resins such as polyethylene terephthalate, acrylic resins, polyvinyl chloride, polystyrene, polyethylene, polypropylene and other polyolefin resins, phenolic resins (including Bakelite), fluorine resins, etc. can be listed. One selected from these can be used or two or more can be combined and used. Among them, with respect to heat resistance, acrylic resins, phenolic resins (including Bakelite) and fluorine resins are preferred. In addition, acrylic resins are also particularly preferred in terms of flexibility during processing.

[0228] When the bonding portion 20 includes a spacer, the content of the spacer in the bonding portion 20 is preferably greater than or equal to 0.1 volume % and less than or equal to 20 volume %, and more preferably greater than or equal to 0.5 volume % and less than or equal to 10 volume %.

[0229] If the joint portion 20 contains a fibrous base material, unintended variations in the thickness of the joint portion 20 can be preferably suppressed. Furthermore, a gap 2 can be preferably formed between the resin material 21 constituting the joint portion 20 and the fibrous base material. Furthermore, when manufacturing the thermal conductor 1, the resin material 21 constituting the joint portion 20 can be effectively prevented from protruding from the end. As a result, the joint portion 20 preferentially contacts the component to which the thermal conductor 1 is applied, effectively preventing interference with contact at the thermal conductor portion 10 and ensuring superior thermal conductivity.

[0230] As described above, examples of the fibrous base material include nonwoven fabrics and woven fabrics, and nonwoven fabrics are more preferred.

[0231] As for the constituent materials of the fibers constituting the fibrous substrate, for example, there are glass, cellulose, polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, polyamide, ethylene / vinyl acetate resin, polyvinyl alcohol, synthetic rubber, etc., and one selected from these or a combination of two or more can be used, but polyester is more preferred, and polyethylene terephthalate is more preferred.

[0232] This can further improve the strength of the fibrous base material and the adhesion between the fibrous base material and the resin material 21 , thereby further improving the durability and reliability of the thermal conductor 1 .

[0233] When the joining portion 20 includes a fibrous base material, the thickness of the fibrous base material is preferably greater than or equal to 3 μm and less than or equal to 300 μm, and more preferably greater than or equal to 5 μm and less than or equal to 100 μm.

[0234] exist Figure 1The thickness of the joint 20 indicated by t2 is preferably greater than or equal to 1 μm and less than or equal to 2000 μm, more preferably greater than or equal to 2 μm and less than or equal to 1500 μm, and particularly preferably greater than or equal to 3 μm and less than or equal to 1000 μm.

[0235] According to this, the effects produced by the above-mentioned present invention can be more significantly exerted.

[0236] The proportion of the joint 20 in the thermal conductor 1 (the proportion in the natural state; the same applies hereinafter) is preferably greater than or equal to 15 volume % and less than or equal to 70 volume %, more preferably greater than or equal to 20 volume % and less than or equal to 65 volume %, particularly preferably greater than or equal to 25 volume % and less than or equal to 60 volume %, and most preferably greater than or equal to 30 volume % and less than or equal to 60 volume %.

[0237] This can sufficiently increase the proportion of the heat conducting portion 10 in the heat conductor 1 and easily improve the flexibility of the heat conductor 1 as a whole, thereby more reliably and significantly exhibiting the effects of the present invention.

[0238] [1–3] Gap

[0239] The gap 2 is a portion of the heat conductor 1 where the heat conducting portion 10 and the bonding portion 20 are not located. The gap 2 generally contains air or a gas generated when the resin material 21 constituting the bonding portion 20 is cured.

[0240] Since the thermal conductor 1 has the void 2, when the thermal conductor 1 is pressed, the void 2 acts as a buffer, absorbing deformation of the thermal conductor 1 (particularly deformation of the joint 20) caused by the pressure, thereby suppressing excessive deformation. Furthermore, the thermal conductor 1 can be given appropriate flexibility, and the amount of protrusion can be appropriately adjusted to meet the aforementioned conditions.

[0241] In the thermal conductor 1 , the cavity 2 is provided at least in a portion adjacent to the joining portion 20 .

[0242] The ratio of the voids 2 in the thermal conductor 1 (the ratio in the natural state; the same applies hereinafter) is preferably greater than or equal to 5 volume % and less than or equal to 65 volume %, more preferably greater than or equal to 5 volume % and less than or equal to 50 volume %, particularly preferably greater than or equal to 6 volume % and less than or equal to 40 volume %, and most preferably greater than or equal to 7 volume % and less than or equal to 32 volume %.

[0243] According to this, the effects produced by the above-mentioned present invention can be more significantly exerted.

[0244] When the proportion of the heat conducting portion 10 in the heat conducting body 1 is denoted by VC [volume %], the proportion of the joint portion 20 in the heat conducting body 1 is denoted by VJ [volume %], and the proportion of the void portion 2 in the heat conducting body 1 is denoted by VV [volume %], it is more preferable to satisfy the relationship of 25 ≤ [(VJ + VV) / (VC + VJ + VV)] × 100 ≤ 90, more preferably to satisfy the relationship of 25 ≤ [(VJ + VV) / (VC + VJ + VV)] × 100 ≤ 85, particularly preferably to satisfy the relationship of 31 ≤ [(VJ + VV) / (VC + VJ + VV)] × 100 ≤ 80, and most preferably to satisfy the relationship of 37 ≤ [(VJ + VV) / (VC + VJ + VV)] × 100 ≤ 75.

[0245] According to this, the effects produced by the above-mentioned present invention can be more significantly exerted.

[0246] The density of the thermal conductor 1 in the state before being pressed (natural state) is preferably equal to or greater than 0.6 g / cm 3 and less than or equal to 2.5g / cm 3 , more preferably greater than or equal to 0.9 g / cm 3 and less than or equal to 2.0g / cm 3 .

[0247] The density of aluminum used in many conventional heat conductors, such as heat sinks, is approximately 2.7 g / cm 3 .

[0248] As for the materials constituting the heat conducting portion 10 and the joining portion 20 in the heat conductor 1 , the materials described above can be used, whereby the overall density is lower than that of conventional heat conductors.

[0249] This makes it possible to make the heat conductor 1 particularly lightweight. Furthermore, when the heat conductor 1 is mounted on an electronic device or the like, it does not hinder the lightweighting of the electronic device or the like. In other words, the electronic device or the like can be made even lighter.

[0250] In addition, if Figure 3 、 Figure 4 As shown in FIG. 1 , the area of ​​the heat conductor 1 when viewed from a second direction perpendicular to the first direction is defined as S3 [cm 2 ], and the area of ​​the heat conductor 1 when viewed from the second direction in a pressed state at 0.2 MPa from the first direction is set to S4 [cm 2 ], the heat conductor 1 preferably satisfies the condition of 5≤[(S3-S4) / S3]×100≤50, more preferably satisfies the condition of 7≤[(S3-S4) / S3]×100≤40, and particularly preferably satisfies the condition of 10≤[(S3-S4) / S3]×100≤25.

[0251] like Figure 3 、 Figure 4 As shown, when the thermal conductor 1 is viewed from above from the second direction, the area S4 of the thermal conductor 1 in the pressed state is smaller than the area S3 of the thermal conductor 1 in the natural state.

[0252] The areas S3 and S4 satisfy the aforementioned conditions, thereby making it possible to more significantly exert the effects of the present invention.

[0253] Furthermore, the values ​​of S3 and S4 may be the average of the areas viewed from two directions perpendicular to the first direction and perpendicular to each other, such as the average of the areas viewed from multiple directions perpendicular to the first direction, for example, the average of the areas viewed from the x-direction and the y-direction. This value will also be used for the values ​​of S3 and S4 in the embodiments described below.

[0254] When the length of the heat conductor 1 in the first direction in the initial state, in other words, in the natural state, is defined as L0 [mm], and the length of the heat conductor 1 in the first direction after 1000 repetitions of pressing at 1.0 MPa in the first direction for one minute, releasing from the pressing state, and allowing to stand for one minute is defined as L1 [mm], it is more preferred that the relationship 0.70 ≤ L1 / L0 be satisfied, more preferably the relationship 0.75 ≤ L1 / L0 be satisfied, and even more preferably the relationship 0.80 ≤ L1 / L0 ≤ 1.00 be satisfied.

[0255] Thus, even if the heat conductor 1 is repeatedly pressed and released, it can still fully recover, making the durability of the heat conductor 1 particularly excellent. In addition, the heat conductor 1 can be suitably reused.

[0256] When the heat conducting portion 10 is formed of a graphite sheet, the relationship is preferably 0.80≤L1 / L0, more preferably 0.83≤L1 / L0, and particularly preferably 0.85≤L1 / L0≤1.00.

[0257] According to this, the aforementioned effects can be more significantly exerted.

[0258] When the heat conducting portion 10 is made of aluminum, it is more preferably 0.70≤L1 / L0, more preferably 0.73≤L1 / L0, and particularly preferably 0.75≤L1 / L0≤1.00.

[0259] According to this, the aforementioned effects can be more significantly exerted.

[0260] When the heat conductor 1 is pressed at 0.2 MPa in the first direction, the measured value of its thermal conductivity in the first direction is preferably greater than or equal to 50 W / (m·K), more preferably greater than or equal to 70 W / (m·K) and less than or equal to 1200 W / (m·K), and particularly preferably greater than or equal to 100 W / (m·K) and less than or equal to 800 W / (m·K).

[0261] This improves the adhesion between the thermal conductor 1 in the pressed state and the member to which it is applied, and makes it possible to significantly improve the substantial thermal conductivity while maintaining a low interfacial thermal resistance.

[0262] Here, the actual value of thermal conductivity can be measured by, for example, a method in accordance with US standard ASTM D5470.

[0263] The actual value of thermal conductivity can also be obtained by, for example, measuring using a thermal diffusivity / thermal conductivity measuring device (AI-Phase Mobile M3 series, manufactured by AI-PHASE). The temperature during measurement can be set to 50°C.

[0264] In the present embodiment, the measured value of the thermal conductivity is a value obtained by measuring a sample whose shape is adjusted so that the surface of the thermal conductor 1 is pressed into a square of 40 mm×40 mm.

[0265] [2] Method for manufacturing a thermal conductor

[0266] Next, a method for producing the thermal conductor according to the present invention will be described.

[0267] Figure 7 This is a cross-sectional view schematically showing a heat conduction portion forming member made of flaky graphite. Figure 8 This is a diagram schematically showing an example of an apparatus used in the bonding portion forming composition attachment step and the winding step. Figure 9 This is a diagram showing a state in which the heat conducting portion forming member is wound on the surface of a reel in a traverse winding method in the winding step. Figure 9 Part (a) is a diagram showing the state of the first roll (first layer) of the heat conduction portion forming member 10 ′ with respect to the winding roll R2. Figure 9 Part (b) is a diagram showing the state of the second roll (second layer) of the heat conduction portion forming member 10 ′. Figure 10 A diagram schematically showing the cut body obtained in the cutting step. Figure 11 This figure schematically shows a state in which the incision body is pressed to further improve its flatness. Figure 12 A diagram schematically showing the slicing step.

[0268] The present invention provides a method for manufacturing a thermal conductor 1 having a plurality of thermally conductive portions 10 and a bonding portion 20 for bonding the thermally conductive portions 10. The method comprises: a thermally conductive portion-forming member preparation step of preparing a thermally conductive portion-forming member 10' for forming the thermally conductive portions 10; and a bonding portion-forming composition attachment step of attaching a bonding portion-forming composition 20' for forming the bonding portion 20 to the surface of the thermally conductive portion-forming member 10'. The thermal conductor 1 further comprises a void 2 in which neither the thermally conductive portion 10 nor the bonding portion 20 exists. The thermal conductor 1 has an area of ​​50 [cm2] when viewed from above from a first direction. 2 ], and the area of ​​the heat conductor 1 when viewed from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2 ], the heat conductor 1 satisfies the condition of 0.5≤[(S1−S0) / S0]×100≤20.

[0269] Thus, a method for manufacturing the thermal conductor 1 can be provided, which can efficiently manufacture the thermal conductor 1 that can both ensure close adhesion to a member in contact during use and suppress excessive deformation during compression.

[0270] The present invention also provides a method for manufacturing a thermal conductor 1 including a plurality of thermally conductive portions 10 and a joint portion 20 for joining the thermally conductive portions 10. The method comprises: a thermally conductive portion-forming member preparing step of preparing a long thermally conductive portion-forming member 10' to be used for forming the thermally conductive portion 10; a joint-forming composition attaching step of attaching a joint-forming composition 20' to be used for forming the joint 20 onto the surface of the thermally conductive portion-forming member 10'; a winding step of winding the thermally conductive portion-forming member 10', to which the joint-forming composition 20' is attached, around the circumference of a reel (winding reel R2) using a transverse winding method to obtain a cylindrical roll 30; and a slitting step of slitting the roll 30 in a direction non-perpendicular to the axial direction of the reel to obtain a slit 40.

[0271] Thus, a method for manufacturing a thermal conductor 1 can be provided, which efficiently manufactures the thermal conductor 1 while simultaneously ensuring close adhesion to contacting members during use and suppressing excessive deformation during compression. In particular, by winding the thermal conductor-forming member 10', to which the bonding portion-forming composition 20' is attached, around the circumference of a reel using a transverse winding method, the thermal conductor 1 can be manufactured more efficiently than, for example, using a blade-like sheet material.

[0272] Furthermore, the method for manufacturing a thermal conductor according to the present embodiment includes a joining portion forming composition preparation step of preparing a joining portion forming composition 20 ′ for forming the joining portion 20 before the joining portion forming composition attachment step.

[0273] [2–1] Steps for preparing components for forming the heat conduction portion

[0274] In the heat conduction portion forming member preparing step, the heat conduction portion forming member 10 ′ used for forming the heat conduction portion 10 is prepared.

[0275] [2-1-1] Member for forming the heat conduction portion

[0276] The heat conduction portion forming member 10 ′ used in the bonding portion forming composition attaching step is a member for forming the heat conduction portion 10 in the heat conductor 1 .

[0277] The shape of the heat conduction portion forming member 10 ′ prepared in this step is not particularly limited, but is an elongated shape in this embodiment.

[0278] This makes it possible to further improve the productivity of the thermal conductor 1 and more effectively suppress unintended variations in characteristics among various portions of the manufactured thermal conductor 1.

[0279] It is more preferable that the heat conduction portion forming member 10 ′ is substantially composed of a single component.

[0280] This can further improve the thermal conductivity of the formed heat conducting portion 10 , and is generally advantageous in reducing the manufacturing cost of the heat conductor 1 .

[0281] The heat conducting portion forming member 10 ′ can be a sheet made of a material corresponding to the heat conducting portion 10 to be formed. In particular, a long (strip-shaped) sheet can be used.

[0282] When a long (strip-shaped) sheet is used as the heat conduction portion forming member 10 ′, it is more preferable that the heat conduction portion forming member 10 ′ is formed in a strip shape having projections and depressions on the main surface.

[0283] This allows the joint-forming composition 20' to adhere appropriately to the surface of the heat-conducting portion-forming member 10'. Furthermore, bubbles can be appropriately contained between the heat-conducting portion-forming member 10' and the joint-forming composition 20'. Furthermore, after the resin material 21 has cured, the joint 20 can be appropriately prevented from falling off from the heat-conducting portion 10. Furthermore, the void 2 can be appropriately formed.

[0284] Specifically, the maximum height roughness Rz of the heat conduction portion forming member 10 ′ is preferably greater than or equal to 0.1 μm and less than or equal to 50 μm, more preferably greater than or equal to 0.5 μm and less than or equal to 30 μm, and particularly preferably greater than or equal to 5.0 μm and less than or equal to 20 μm.

[0285] This can make the above-mentioned effects more significant.

[0286] The maximum height roughness Rz of the heat conduction portion forming member 10 ′ can be measured by a method in accordance with JIS B0601-2013, for example.

[0287] When a long (strip-shaped) sheet is used as the heat conduction portion forming member 10 ′, the thickness of the heat conduction portion forming member 10 ′ is preferably 5 μm or more and 500 μm or less, and more preferably 10 μm or more and 200 μm or less.

[0288] This can significantly increase the proportion of the heat conducting portion 10 in the heat conductor 1, and easily improve the flexibility of the heat conductor 1 as a whole, thereby more reliably and significantly exhibiting the effects of the present invention.

[0289] When a long (strip-shaped) sheet is used as the heat conduction portion forming member 10 ′, its width is preferably greater than or equal to 2 mm and less than or equal to 70 mm, and more preferably greater than or equal to 5 mm and less than or equal to 50 mm.

[0290] This significantly increases the proportion of the heat conducting portion 10 within the heat conducting body 1, while also making it easier to enhance the overall flexibility of the heat conducting body 1, thereby more reliably and significantly achieving the aforementioned effects of the present invention. Furthermore, the heat conducting portion-forming member 10' can be made easier to handle, further improving the productivity of the heat conducting body 1 and facilitating production.

[0291] When a long (strip-shaped) sheet is used as the heat conducting portion forming member 10', the use of a sheet containing graphite (graphite sheet) as the heat conducting portion forming member 10' can improve the actual thermal conductivity between the member to which the heat conducting body 1 is applied and the heat conducting body 1, while also reducing the manufacturing cost of the heat conducting body 1. Furthermore, the flexibility and softness of the heat conducting body 1 can be improved. For example, the restoring force of the heat conducting body 1 when bent can be improved. Furthermore, the cushioning properties created by the internal voids and the improved contact properties due to moderate deformation when in contact with the overheating portion can be improved.

[0292] Furthermore, when using a long (strip-shaped) sheet as the heat conducting portion-forming member 10', for example, a sheet made of carbon fiber (carbon fiber paper-made sheet) can be used as the heat conducting portion-forming member 10'. This can improve the actual thermal conductivity between the member to which the heat conducting element 1 is applied and the heat conducting element 1, while also reducing the manufacturing cost of the heat conducting element 1. Furthermore, the flexibility and softness of the heat conducting element 1 can be improved, for example, by improving the resilience of the heat conducting element 1 when bent, and even by improving the cushioning properties created by internal voids and the improved contact properties due to moderate deformation when in contact with the overheating portion.

[0293] Furthermore, when using a long (strip-shaped) sheet as the heat conducting portion-forming member 10', for example, a sheet made of a metal material (metal sheet) can be used as the heat conducting portion-forming member 10'. This can improve the actual thermal conductivity between the member to which the heat conducting element 1 is applied and the heat conducting element 1, while also reducing the manufacturing cost of the heat conducting element 1. Furthermore, the strength of the internal bonding force of the metal material can further reduce the dust generation of the heat conducting element 1. Furthermore, when a relatively large load is applied to the heat conducting element 1, irreversible deformation of the heat conducting element 1, such as collapse due to buckling, can be more effectively prevented.

[0294] Furthermore, the heat conduction portion forming member 10 ′ may be made of a heat conductive material and may be made of fibers extending in the longitudinal direction of the heat conduction portion forming member 10 ′.

[0295] When fibers are used as the heat conduction portion forming member 10 ′, the heat conduction portion forming member 10 ′ may include a fiber bundle extending in the longitudinal direction of the heat conduction portion forming member 10 ′.

[0296] This allows the joint-forming composition 20' to adhere appropriately to the gaps between the fiber bundles, and the amount of the joint-forming composition 20' adhered to the heat-conducting portion-forming member 10' can be adjusted appropriately. Furthermore, bubbles can be appropriately contained between the heat-conducting portion-forming member 10' and the joint-forming composition 20'. Furthermore, after the resin material 21 has cured, the joint 20 can be appropriately prevented from falling off from the heat-conducting portion 10. Furthermore, the void 2 can be appropriately formed.

[0297] The fiber bundle may be a primary fiber bundle in which dozens of single fibers are gathered together to form a bundle, or may be a secondary fiber bundle in which dozens of the primary fiber bundle are gathered together to form a larger bundle.

[0298] When using fibers as the heat conducting portion-forming member 10', carbon fibers are preferably used. This improves the actual thermal conductivity between the member to which the heat conductor 1 is applied and the heat conductor 1, while also reducing the manufacturing cost of the heat conductor 1. Furthermore, the flexibility and softness of the heat conductor 1 can be enhanced. For example, the heat conductor 1 can have enhanced resilience when bent, and even achieves enhanced cushioning properties due to internal voids and improved contact properties due to moderate deformation when in contact with the overheating portion.

[0299] Furthermore, when using fibers as the heat conducting portion-forming member 10', metal fibers can be used. This improves the actual thermal conductivity between the component to which the heat conductor 1 is applied and the heat conductor 1, while also reducing the manufacturing cost of the heat conductor 1. Furthermore, the strength of the bonding force within the metal material can further reduce the dust generation of the heat conductor 1. Furthermore, even when a relatively large load is applied to the heat conductor 1, irreversible deformation of the heat conductor 1, such as collapse due to buckling, can be more effectively prevented.

[0300] [2–1–1–1] Graphite sheet

[0301] The graphite sheet may contain components other than graphite, such as a binder or resin fibers, in addition to graphite. However, it is more preferably composed substantially of graphite alone, that is, composed substantially of a single component.

[0302] As graphite, flake graphite is more preferred.

[0303] Thus, the flaky graphite can be appropriately oriented in the extending direction of the heat conducting portion 10 , and the heat conductivity of the heat conducting portion 10 in the extending direction can be made particularly excellent.

[0304] More specifically, when flake graphite is compacted into flakes, Figure 7 As shown, the flaky graphite FG is oriented in the in-plane direction of the sheet. That is, the thickness direction of the flaky graphite FG is appropriately oriented along the thickness direction of the sheet. Consequently, when used as a heat conductor 1, the heat conduction portion 10 exhibits particularly excellent thermal conductivity in the direction in which it extends.

[0305] The graphite sheet is preferably produced, for example, by a method comprising the following steps: a pressing step of pressing flaky graphite to form a sheet; a drying step of drying the flaky graphite; and a heating and pressing step of heating and pressing (hot pressing) the flaky graphite.

[0306] In the pressurizing step, the graphite is pressurized and formed into a sheet. The pressurizing step can be suitably performed at, for example, a temperature of 10°C or higher and 35°C or lower. The pressing pressure can be, for example, 1 MPa or higher and 30 MPa or lower. The composition used for forming can contain water, a binder, and the like in addition to graphite. Furthermore, in the pressurizing step, a composition containing other components, such as a binder, can be used in addition to graphite. Such components can be removed or carbonized by treatments such as heating, and can be suitably prevented from remaining in the resulting graphite sheet.

[0307] In the drying step, the graphite sheet is dried. This removes excess water and other volatile components, improving handling. It also enhances the shape stability and strength of the graphite sheet.

[0308] The drying step can be performed by reducing pressure, heating, or natural drying. When the drying step is performed by heating, the heating temperature can be set to 40°C or higher and 100°C or lower.

[0309] During the heating and pressing step, the graphite sheet is heated and pressed in the thickness direction. This allows for more optimal orientation of the fibrous graphite, improving the shape stability and strength of the graphite sheet.

[0310] The heating temperature in the heating and pressing step can be set to, for example, 100°C or higher and 400°C or lower. This can more effectively prevent unintended retention of moisture, binder, etc. in the resulting graphite sheet. Furthermore, the pressing pressure in the heating and pressing step can be set to, for example, 10 MPa or higher and 40 MPa or lower.

[0311] In addition, if Figure 7 As shown, when the flaky graphite FG is compacted into a sheet shape, the flaky graphite FG is densely compacted and hardened near the surface of the graphite sheet. On the other hand, near the center portion in the thickness direction of the graphite sheet, the flaky graphite FG is roughly solidified and relatively soft, forming a void portion.

[0312] In this way, if the heat conducting portion forming member 10' has a void portion inside (particularly, near the center portion in the thickness direction), the curable resin material 21' can penetrate the void portion inside the heat conducting portion forming member 10', thereby improving the adhesion between the heat conducting portion 10 and the joint portion 20 in the manufactured heat conducting body 1 and the durability of the heat conducting body 1.

[0313] The density of the graphite sheet as a whole is preferably greater than or equal to 0.3 g / cm 3 and less than or equal to 2.1g / cm 3, more preferably greater than or equal to 0.6 g / cm 3 and less than or equal to 1.8g / cm 3 , especially preferably greater than or equal to 0.9 g / cm 3 and less than or equal to 1.5g / cm 3 .

[0314] This makes it possible to make the thermal conductivity and strength of the graphite sheet alone in the surface direction particularly excellent.

[0315] Examples of graphite sheets that meet these conditions include GRAFOIL (manufactured by NeoGraf), PERMA FOIL (manufactured by Toyo Tan), carbon sheet (manufactured by Tokyo Ceramics), PGS graphite sheet (manufactured by Panasonic), and GRAPHINITY (manufactured by Kaneka).

[0316] [2–1–1–2] Sheet metal

[0317] As for the metal sheet, in addition to using metal materials, components other than metal materials, such as binders or resin fibers, may also be used. However, it is more preferred that it is substantially composed of only metal materials, that is, substantially composed of a single component.

[0318] As the metal sheet, for example, a metal foil obtained by rolling a metal material into a sheet shape can be preferably used.

[0319] As for the metal material constituting the metal sheet, various single metals or alloys can be listed, and one or more of these can be selected and used in combination, but it is more preferred to include one or more selected from the group consisting of Al, Cu, Ag, Au, Mg and Zn.

[0320] As a result, the heat conductivity of the formed heat conducting portion 10 can be further improved.

[0321] [2–1–1–3] Carbon fiber

[0322] In addition, examples of the carbon fibers constituting the heat conduction portion forming member 10 ′ include pitch-based and PAN-based carbon fibers, but pitch-based carbon fibers are more preferred.

[0323] Examples of pitch-based carbon fibers include isotropic pitch-based and mesophase pitch-based carbon fibers, with mesophase pitch-based carbon fibers being more preferred.

[0324] Additionally, the carbon fibers may contain graphite.

[0325] The roughness of the carbon fibers (when the heat conduction portion forming member 10' comprises a fiber bundle, the roughness of the single fibers constituting the fiber bundle) is not particularly limited, but is preferably greater than or equal to 1 μm and less than or equal to 20 μm, more preferably greater than or equal to 3 μm and less than or equal to 15 μm, and particularly preferably greater than or equal to 5 μm and less than or equal to 12 μm.

[0326] According to this, the above-mentioned effects can be more significantly exerted.

[0327] When the heat conduction portion forming member 10' includes a fiber bundle extending along its longitudinal direction, the roughness of the fiber bundle (carbon fiber bundle) is preferably greater than or equal to 1.0 mm and less than or equal to 30 mm, more preferably greater than or equal to 1.5 mm and less than or equal to 20 mm, and particularly preferably greater than or equal to 2.0 mm and less than or equal to 15 mm.

[0328] In addition, the heat conducting portion forming member 10 ′ can be made more easily handled, thereby further improving the productivity of the heat conducting body 1 and facilitating production.

[0329] [2–2] Preparation step of the composition for forming a joint

[0330] In the joining portion forming composition preparation step, a joining portion forming composition 20 ′ to be used for forming the joining portion 20 is prepared.

[0331] [2–2–1] Joint-forming composition

[0332] The joint forming composition 20 ′ used in the joint forming composition attaching step is a composition for forming the joint 20 in the thermal conductor 1 and contains a curable resin material 21 ′.

[0333] The curable resin material 21' is not particularly limited as long as the cured resin material 21 has flexibility. A precursor of the aforementioned resin material 21, such as an uncured material or a semi-cured material, can be used.

[0334] In addition, it is more preferable that the curable resin material 21 ′ is a material that generates gas in a curing step described later.

[0335] Thereby, the cavity 2 can be preferably formed in the thermal conductor 1 .

[0336] The bonding portion forming composition 20 ′ may contain, for example, metal particles, ceramic particles, spacers, and the like.

[0337] According to this, the bonding portion 20 containing these components can be formed, and the aforementioned effects can be obtained.

[0338] When the joint forming composition 20 ′ contains these components, it is preferred to adjust the content in the joint forming composition 20 ′ so that the content in the joint 20 of the finally obtained thermal conductor 1 falls within the above-mentioned range.

[0339] The bonding portion forming composition 20 ′ may contain components other than the above-mentioned components.

[0340] As for such ingredients, for example, plasticizers, colorants, antioxidants, ultraviolet absorbers, light stabilizers, softeners, modifiers, rust inhibitors, fillers, electromagnetic wave absorbers such as granulated iron, surface lubricants, corrosion inhibitors, heat stabilizers, lubricants, primers, antistatic agents, polymerization inhibitors, crosslinking agents, catalysts, leveling agents, tackifiers, dispersants, anti-aging agents, flame retardants, hydrolysis inhibitors, corrosion inhibitors, etc. can be listed.

[0341] However, the content of these components in the bonding portion forming composition 20 ′ is more preferably 5% by weight or less, more preferably 3% by weight or less, and particularly preferably 1% by weight or less.

[0342] Furthermore, it is more preferable that the joint forming composition 20' does not contain a solvent component. This can prevent the solvent component from unintentionally remaining in the thermal conductor 1 obtained in the end, and can further improve the reliability of the thermal conductor 1.

[0343] [2–3] Step of attaching the joint forming composition

[0344] In the joining portion forming composition attaching step, the joining portion forming composition 20 ′ for forming the joining portion 20 is attached to the surface of the heat conduction portion forming member 10 ′.

[0345] In this embodiment, the bonding portion forming composition 20 ′ contains a curable resin material 21 ′.

[0346] As for the method of making the bonding portion forming composition 20' adhere to the surface of the heat conducting portion forming member 10', for example, various coating methods, transfer methods, dipping methods, etc. can be used. More specifically, for example, a method of applying the composition using any one of a rod coater, a roll coater, a reverse roll coater, a gravure coater, a die coater, a kiss coater, a stick coater, a dip coater, and a spray coater can be mentioned.

[0347] This allows the joint forming composition 20 ′ to be continuously and appropriately adhered to the surface of the heat conducting portion forming member 10 ′, thereby improving the reliability and productivity of the manufactured heat conducting body 1 and facilitating production.

[0348] For example, this step can be performed using Figure 8 The heat conduction portion forming member 10' is formed by a device (dip coating machine) shown in FIG. More specifically, a diaphragm roll R1 is prepared in advance in which the heat conduction portion forming member 10' is wound into a roll. Next, the heat conduction portion forming member 10', which is a diaphragm, is pulled out from the diaphragm roll R1 and is guided and transported by a guide roller R3. Furthermore, for example, the heat conduction portion forming member 10' is immersed in a liquid receiving tank M in which a liquid bonding portion forming composition 20' is retained. Accordingly, the bonding portion forming composition 20' in the liquid receiving tank M adheres to the surface of the heat conduction portion forming member 10'.

[0349] Since the bonding portion forming composition 20 ′ can be attached to both surfaces of the heat conduction portion forming member 10 ′ by using a dip coater, the bonding portion forming composition 20 ′ can be attached continuously and efficiently in the attachment step.

[0350] In the bonding portion forming composition attaching step, it is more preferable to include air bubbles between the heat conduction portion forming member 10 ′ and the bonding portion forming composition 20 ′.

[0351] Thus, after the resin material 21 is cured, the gap 2 can be preferably formed between the heat conducting portion 10 and the joining portion 20 .

[0352] Methods for creating bubbles between the heat conduction portion forming member 10' and the bonding portion forming composition 20' include, for example, adjusting the surface shape of the heat conduction portion forming member 10', the viscosity of the bonding portion forming composition 20', or the wettability of the heat conduction portion forming member 10', and adjusting the pitch and winding speed when the long heat conduction portion forming member 10' is transversely wound in the winding step described later.

[0353] Furthermore, after the bonding portion forming composition 20 ′ is attached to the heat conduction portion forming member 10 ′, the gas generated during the curing reaction may be utilized for the formation of bubbles (formation of the cavity 2 ).

[0354] This step is preferably performed using the heated bonding portion forming composition 20 ′ so that the viscosity of the bonding portion forming composition 20 ′ is lower than the viscosity at room temperature (20° C.).

[0355] Accordingly, in this step, the joint-forming composition 20' can be more appropriately attached to the heat-conducting portion-forming member 10', and after this step is completed, for example, the joint-forming composition 20' attached to the heat-conducting portion-forming member 10' can be cooled during the winding step to set the viscosity of the joint-forming composition 20' lower than that of this step. As a result, in steps subsequent to the joint-forming composition attachment step, the joint-forming composition 20' attached to the heat-conducting portion-forming member 10' can be more effectively prevented from unexpectedly escaping. In addition, the aforementioned bubbles can be more appropriately prevented from unexpectedly disappearing in a subsequent step (for example, by pressing during the winding step), and a heat conductor 1 with appropriately formed voids 2 can be more reliably obtained.

[0356] The heating temperature of the bonding portion forming composition 20 ′ in this step is not particularly limited, but is preferably set so that the viscosity of the bonding portion forming composition 20 ′ satisfies the following conditions.

[0357] The viscosity of the bonding portion forming composition 20' when the bonding portion forming composition 20' is attached to the heat conduction portion forming member 10' is preferably greater than or equal to 500 mPa·s and less than or equal to 50,000 mPa·s, more preferably greater than or equal to 1,500 mPa·s and less than or equal to 45,000 mPa·s, and particularly preferably greater than or equal to 2,000 mPa·s and less than or equal to 40,000 mPa·s.

[0358] This allows the bonding portion forming composition 20' to be more appropriately attached to the heat conduction portion forming member 10' at a predetermined thickness and a predetermined ratio. In addition, bubbles can be more appropriately contained between the heat conduction portion forming member 10' and the bonding portion forming composition 20'.

[0359] In addition, the viscosity of the bonding portion forming composition 20 ′ can be determined by measurement in accordance with JIS Z8803:2011.

[0360] Furthermore, for example, multiple types of joint-forming compositions 20' may be used in this step, or a combination of materials containing only a portion of the components of the aforementioned joint-forming composition 20' and materials containing a portion of the other components may be used. More specifically, for example, in this step, a joint-forming composition 20' containing a curable resin material 21 and no spacers may be used. Between this step and the winding step, a spacer may be applied to the heat-conducting portion-forming member 10' to which the joint-forming composition 20' is attached.

[0361] [2–4] Winding steps

[0362] In the winding step, the heat conduction portion forming member 10 ′ to which the bonding portion forming composition 20 ′ is adhered is wound around the circumferential surface of the winding reel R2 by a traverse winding method, thereby obtaining a cylindrical wound body 30 .

[0363] [2–4–1] Transverse Winding

[0364] Figure 9 The figure schematically shows the state of the transverse winding adopted in the present invention. Figure 9 The case of performing traverse winding in two directions will be described as an example.

[0365] In addition, Figure 9 The illustration of the bonding portion forming composition 20 ′ is omitted, and only the heat conduction portion forming member 10 ′ is shown.

[0366] like Figure 9 As shown in part (a), with the take-up reel R2 in the first roll (first layer), the heat conductive portion-forming member 10', with the bonding portion-forming composition 20' attached to its surface, is wound in the direction indicated by arrow D1, tilted relative to the take-up reel R2. Specifically, the heat conductive portion-forming member 10' is wound in a direction d1 tilted positively by an angle θ3 relative to a line v perpendicular to the central axis c of the take-up reel R2.

[0367] The heat conduction portion forming member 10 ′ is wound transversely from one end of the winding reel R2 in the longitudinal direction toward the other end, but does not necessarily need to be wound from one end. For example, it may be wound from near the center of the winding reel R2 in the longitudinal direction.

[0368] Thus, as for the method of winding the heat conduction portion forming member 10', publicly known methods can be used. For example, when supplying the heat conduction portion forming member 10' from a certain direction, the winding angle can be appropriately changed while rotating the winding reel R2. In this embodiment, when winding the heat conduction portion forming member 10' onto the winding reel R2, it is more preferable to maintain a gap g1 between adjacent heat conduction portion forming members 10'. In this way, by performing transverse winding with a gap, deformation of the heat conduction portion forming member 10' can be more effectively suppressed. In addition, by performing transverse winding with a gap, when winding into the second roll or more, it is possible to effectively suppress the disorder of the heat conduction portion forming member 10' on the lower side (the side closer to the winding reel R2).

[0369] Examples of the winding method include a method of fixing the winding reel R2 and swinging a guide (not shown) for guiding the conveyance of the heat conduction portion forming member 10 ′ to perform transverse winding; or a method of fixing the guide and swinging the winding reel R2 to perform transverse winding.

[0370] When the heat-conducting portion-forming member 10' is in a strip (flat) shape, it is preferable to use a method of swinging the take-up reel R2 for transverse winding. Swinging the take-up reel R2 for transverse winding facilitates maintaining the strip (flat) shape. Furthermore, when winding the heat-conducting portion-forming member 10', it is preferable to wind it so that the heat-conducting portion-forming member 10' does not become skewed.

[0371] In this embodiment, the gap g1 of the heat conduction portion forming member 10 ′ during transverse winding is preferably greater than or equal to 20 μm and less than or equal to 2000 μm, more preferably greater than or equal to 30 μm and less than or equal to 1500 μm, and particularly preferably greater than or equal to 40 μm and less than or equal to 1000 μm.

[0372] This significantly increases the proportion of the heat conducting portion 10 in the manufactured heat conducting body 1, while also improving the overall flexibility of the heat conducting body 1 and further significantly enhancing the effects of the present invention. Furthermore, it effectively prevents the heat conducting portion forming member 10' from slipping or becoming disorganized during the manufacture of the heat conducting body 1.

[0373] like Figure 9 As shown in part (b) of FIG, the heat conductive portion forming member 10' is wound in the direction indicated by arrow D2, with the winding reel R2 in the second roll (second layer) state, along a direction d2 that is tilted negatively at an angle θ4 relative to a line v perpendicular to the central axis c of the winding reel R2. Specifically, the tilt direction d2 relative to the line v perpendicular to the central axis c is opposite to the tilt direction d1 of the first winding.

[0374] This effectively prevents unintended movement (deviation) of the heat conductor-forming member 10' during the manufacture of the heat conductor 1, allowing for easy and reliable manufacture of the desired operating heat conductor 1. Furthermore, even when a relatively large load is applied to the manufactured heat conductor 1, irreversible deformation of the heat conductor 1, such as collapse due to buckling, can be more effectively suppressed, resulting in improved durability of the heat conductor 1. Furthermore, when the heat conductor 1 is compressed in the first direction, surface pressure is more easily applied to the heat conductor 1, further improving the adhesion between the heat conductor 1 and the member to which it is applied. Furthermore, when pressure is applied to the heat conductor 1 in the first direction, this pressure includes a component of force in the direction of pressing the heat conductor 10 and the joint 20, further improving the adhesion between the heat conductor 10 and the joint 20.

[0375] Even in the second winding, the heat conduction portion forming member 10 ′ is wound while maintaining the gap g2 between adjacent heat conduction portion forming members 10 ′.

[0376] The gap g2 for traverse winding of the second roll may be the same as or different from the gap g1 of the first roll (first layer). A more preferred range of the gap g2 is the same as the gap g1.

[0377] The absolute values ​​of the angles θ3 and θ4 for transverse winding are preferably greater than or equal to 0.3° and less than or equal to 20°, more preferably greater than or equal to 0.5° and less than or equal to 10°, and particularly preferably greater than or equal to 0.7° and less than or equal to 10°.

[0378] Thus, when the end of the winding roll R2 is folded back to form the heat conducting portion, deformation can be more effectively suppressed. Furthermore, in the resulting heat conductor 1, the values ​​of θ1 and θ2 (the angle formed between the normal direction of the surface and the direction in which the heat conducting portion 10c extends) can be easily adjusted to fall within the aforementioned range, allowing the aforementioned effects to be more reliably achieved.

[0379] The angle of the transverse winding is not a mathematically precise numerical value and may include common errors in the technical field of the present invention. For example, a difference of less than 1° is interpreted as an error in transverse winding in the same direction.

[0380] The winding speed when the heat conduction portion forming member 10 ′ is transversely wound is not particularly limited, but is preferably greater than or equal to 1.0 m / minute and less than or equal to 100 m / minute, more preferably greater than or equal to 1.5 m / minute and less than or equal to 50.0 m / minute, and particularly preferably greater than or equal to 2.0 m / minute and less than or equal to 15.0 m / minute.

[0381] This suppresses deformation of the heat conducting portion-forming member 10', allows for more appropriate transverse winding, and facilitates more appropriate control of the amount of adhesion of the bonding portion-forming composition 20'. Furthermore, bubbles can be more appropriately contained between the heat conducting portion-forming member 10' and the bonding portion-forming composition 20', allowing for more appropriate formation of the voids 2 in the heat conductor 1 after the resin material 21 has cured.

[0382] The winding tension when transversely winding the heat conduction portion forming member 10 ′ is not particularly limited, but is preferably 1 N or more and 100 N or less, more preferably 5 N or more and 50 N or less, and particularly preferably 5 N or more and 20 N or less.

[0383] This suppresses deformation of the heat conducting portion-forming member 10', allows for more appropriate transverse winding, and facilitates more appropriate control of the amount of adhesion of the bonding portion-forming composition 20'. Furthermore, bubbles can be more appropriately contained between the heat conducting portion-forming member 10' and the bonding portion-forming composition 20', allowing for more appropriate formation of the voids 2 in the heat conductor 1 after the resin material 21 has cured.

[0384] In the winding step, one heat conductive portion forming member 10' (heat conductive portion forming member 10' with the bonding portion forming composition 20' attached thereto) may be wound around the circumference of one winding reel R2. However, it is more preferred to wind a plurality of heat conductive portion forming members 10' with the bonding portion forming composition 20' attached thereto around the circumference of one winding reel R2 to obtain a single wound body 30 using these members.

[0385] Multiple heat-conducting portion-forming members 10', each with a bonding portion-forming composition 20' attached thereto, are arranged along the longitudinal direction of a single take-up reel R2. Specifically, the circumference of the take-up reel R2 is divided into multiple regions along the longitudinal direction, and a single heat-conducting portion-forming member 10' is transversely wound around the circumference of each region.

[0386] The region where one heat conduction portion forming member 10 ′ is wound may partially overlap with the region where the adjacent heat conduction portion forming member 10 ′ is wound.

[0387] This method can suppress deformation of the heat conducting portion forming member 10' during lateral winding without increasing the size of the device, and can more efficiently produce the wound body 30, thereby further improving the productivity of the heat conducting body 1. Furthermore, it can more effectively suppress the occurrence of differences in characteristics between individual heat conducting bodies 1 manufactured in the same batch.

[0388] The wound body 30 thus obtained has a structure in which portions formed of the heat conduction portion forming member 10 ′ and portions formed of the bonding portion forming composition 20 ′ are alternately arranged from the center toward the outer periphery.

[0389] In addition, Figure 8 , the heat conduction portion forming member 10 ′ is shown being conveyed by being guided by the guide roller R3 , but the heat conduction portion forming member 10 ′ may be conveyed by guide rollers (not shown) other than the guide roller R3 , and the conveying direction may be changed by the guide rollers as needed.

[0390] The diameter of the winding reel R2 around which the heat conduction portion forming member 10 ′ to which the bonding portion forming composition 20 ′ is attached is not particularly limited, but is preferably 10 cm or more and 100 cm or less, and more preferably 20 cm or more and 60 cm or less.

[0391] Accordingly, deformation of the heat conduction portion forming member 10' can be suppressed, and the winding can be more appropriately performed laterally. Moreover, when the wound body 30 is cut into the cut body 40 in the subsequent cutting step, deformation caused by the difference in curvature between the inner and outer peripheries of the wound body 30 can be suppressed, and the wound body 30 can be obtained more efficiently.

[0392] In the illustrated configuration, the heat conducting portion forming member 10' to which the bonding portion forming composition 20' is adhered is wound around the circumference of the winding reel R2 having a true circular cross section. However, the present invention is not limited thereto and may be wound around the circumference of a reel having an elliptical, polygonal, or track-shaped cross section.

[0393] Furthermore, when the joining portion 20 is formed by including the aforementioned fibrous base material, the fibrous base material may be wound around the take-up reel R2 together with the aforementioned heat conduction portion forming member 10 ′ in the winding step.

[0394] In this case, the fibrous base material may be a base material to which the joining portion forming composition 20 ′ is applied in the same manner as described above, or may be a base material to which the joining portion forming composition 20 ′ is not applied.

[0395] When a fibrous substrate is provided with a joint-forming composition 20', the heat-conducting portion-forming member 10' may be provided with the joint-forming composition 20' as described above, or may be provided without the joint-forming composition 20'. In other words, during the step of applying the joint-forming composition, the joint-forming composition 20' may be applied to the fibrous substrate instead of the heat-conducting portion-forming member 10'.

[0396] When a fibrous substrate is used, it may be used in a state where an adhesive is applied to at least a portion of its surface.

[0397] [2–5] Cutting steps

[0398] In the slitting step, the wound body 30 is slit in a direction that is non-perpendicular to the axial direction of the take-up reel R2 to obtain a slit body 40 .

[0399] By cutting the wound body 30 before the curing step of curing the curable resin material 21 ′, the joint portion 20 including the resin material 21 which is a cured product of the curable resin material 21 ′ can be cut in a softer state.

[0400] In this step, a notch is inserted in the winding direction of the winding body 30 in a non-perpendicular direction relative to the axial direction of the cylindrical winding reel R2, and covers from one end to the other end of the axial direction of the winding reel R2. The winding body 30 is opened at the notch and removed from the winding reel R2 as a cut body 40.

[0401] The direction in which the wound body 30 is cut is not particularly limited, as long as it is non-perpendicular to the axial direction of the take-up reel R2. For example, it may be substantially parallel to the axial direction of the take-up reel R2 or it may be oblique to the axial direction of the reel. Furthermore, the wound body 30 may be cut at different locations. For example, it may be cut at a location substantially parallel to the axial direction of the take-up reel R2 or at a location oblique to the axial direction of the reel.

[0402] The method for cutting the wound body 30 is not particularly limited, and examples thereof include methods using the teeth of a band saw, a cutter blade, a trimming knife, a laser, an ultrasonic cutter, a water jet, and the like.

[0403] [2–6] Hardening steps

[0404] In the curing step, the curable resin material 21 ′ contained in the joint forming composition 20 ′ is cured in the cut body 40 .

[0405] In the present embodiment, after the cutting step, a curing step of curing the curable resin material 21 ′ contained in the cut body 40 is performed.

[0406] like Figure 10 As shown, when the wound body 30 is cut to form the cut body 40, the cut body 40 is usually in a curved state. If the curable resin material 21' is cured before the wound body 30 is cut, and the flatness of the curved cut body 40 is improved, deformation will occur due to the difference in curvature between the inner and outer circumferences of the cut body 40. This can easily cause peeling or reduced adhesion between the heat conducting portion 10 and the joint portion 20, damage to the joint portion 20, or damage to the joints between the heat conducting portions 10. In contrast, by cutting the wound body 30 and curing the curable resin material 21' of the cut body 40 to improve its flatness, the occurrence of the aforementioned problems can be effectively prevented.

[0407] This step can be performed, for example, by curing the curable resin material 21 ′ in a state where the inner and outer peripheral sides of the cut body 40 are in contact with a flat surface.

[0408] More specifically, for example, Figure 11As shown, the cut body 40 is sandwiched between two flat plates 90 and pressure is applied, thereby curing the curable resin material 21 ′ while improving the flatness of the heat conducting portion 10 and the bonding portion 20 to obtain the resin material 21 .

[0409] The pressure at this time is not particularly limited, but is preferably greater than or equal to 0 MPa and less than or equal to 100 MPa, more preferably greater than or equal to 1 MPa and less than or equal to 80 MPa, and particularly preferably greater than or equal to 10 MPa and less than or equal to 50 MPa.

[0410] If the pressure falls below the aforementioned lower limit, it may be difficult to achieve a sufficient flatness of the heat conducting portion 10 and the joint 20. On the other hand, if the pressure exceeds the aforementioned upper limit, significant loss of the curable resin material 21' from between adjacent heat conducting portion-forming members 10' may occur, making it difficult to form the joint 20 of the desired thickness. Furthermore, bubbles contained between the heat conducting portion-forming member 10' and the joint-forming composition 20' may collapse, or gases generated during the curing of the curable resin material 21' may be released, making it difficult to properly form the void 2 in the heat conducting body 1 after the resin material 21 has cured.

[0411] Furthermore, by pressing the cut body 40 and performing the hardening step simultaneously, it is possible to more effectively prevent peeling or a decrease in adhesion between the heat conducting portion 10 and the joint portion 20, damage to the joint portion 20, or damage to the joints between the heat conducting portions 10, thereby further improving the durability of the heat conducting body 1.

[0412] 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 greater than or equal to 80°C and less than or equal to 220°C, and more preferably greater than or equal to 100°C and less than or equal to 190°C.

[0413] Thereby, the curable resin material 21 ′ can be cured more appropriately.

[0414] After the above steps, the heat conductor 1 is obtained by processing it into a predetermined shape as needed.

[0415] [2–7] Slicing steps

[0416] When the heat conductor 1 to be manufactured is in the form of a sheet, after the aforementioned hardening step, a slicing step is performed to slice the sheet into sheets with the heat conducting portion 10 and the joining portion 20 exposed on both sides.

[0417] Thereby, for example, a sheet-shaped thermal conductor 1 having a desired thickness can be obtained.

[0418] After the hardening step, e.g. Figure 12 By slicing along cutting lines CC' and DD' in FIG. 1 , a sheet-shaped heat conductor 1 having a thickness T3 can be obtained.

[0419] Here, even if the thickness T3 of the sheet-shaped thermal conductor 1 to be manufactured is relatively small, the curable resin material 21 ′ becomes a resin material 21 with higher shape stability after the curing step, so the thermal conductor 1 can be easily sliced.

[0420] The slicing method is not particularly limited, and examples thereof include methods using a cutter knife, a trimming knife, a laser, an ultrasonic cutter, a water jet, and the like.

[0421] The slicing direction may be substantially parallel to the thickness direction of the cut body 40 or may be oblique to the thickness direction of the cut body 40 , but it is more preferred to be oblique to the thickness direction of the cut body 40 .

[0422] Thus, in the finally obtained heat conductor 1, the values ​​of θ1 and θ2 (the angle formed by the normal direction of the surface and the extending direction of the through heat conducting portion 10c) can be easily adjusted to the values ​​in the aforementioned range, and the aforementioned effect can be more reliably obtained.

[0423] The absolute value of the angle formed by the slicing direction and the thickness direction of the cut body 40 is preferably greater than or equal to 2° and less than or equal to 45°, more preferably greater than or equal to 3° and less than or equal to 40°, and particularly preferably greater than or equal to 4° and less than or equal to 35°.

[0424] According to this, the aforementioned effects are more significantly exerted.

[0425] The slicing direction is not particularly limited, but is preferably substantially parallel to the winding direction (the axial direction of the take-up reel R2). More specifically, the absolute value of the angle formed by the slicing direction and the winding direction (the axial direction of the take-up reel R2) is preferably greater than or equal to 0° and less than or equal to 10°, more preferably greater than or equal to 0° and less than or equal to 7°, and particularly preferably greater than or equal to 0° and less than or equal to 5°.

[0426] The surface of the thermal conductor 1 , particularly the exposed surface of the thermal conductive portion 10 and the bonding portion 20 , may be polished to thereby appropriately adjust the surface roughness of the thermal conductor 1 .

[0427] The surface roughness Ra of the thermal conductor 1 in its natural state is preferably 0.1 μm or more and 80 μm or less, more preferably 0.1 μm or more and 30 μm or less, and particularly preferably 0.1 μm or more and 10 μm or less.

[0428] This makes it possible to more appropriately follow the surface shape of a member to which the heat conductor 1 is applied, and to further improve the substantial heat conductivity between the member and the heat conductor 1 .

[0429] The surface roughness Ra of the thermal conductor 1 can be measured, for example, by a method in accordance with JIS B 0601-2013.

[0430] [3] Usage of heat conductors

[0431] Next, the usage of the heat conductor 1 will be described.

[0432] Figure 13 For schematic display Figure 5 FIG. 1 is a diagram showing an example of a usage mode of a heat conductor shown. Figure 14 For schematic display Figure 5 FIG. 1 is a diagram showing an example of a usage mode of a heat conductor shown. Figure 15 For schematic display Figure 1 FIG. 1 is a diagram showing an example of a usage mode of a heat conductor shown. Figure 16 For schematic display Figure 1 FIG. 1 is a diagram showing an example of a usage mode of a heat conductor shown.

[0433] The heat conductor 1 can be used, for example, as various heat dissipation components; or as a heat transfer component that contacts a high-temperature component and a heat dissipation component and transfers heat from the high-temperature component to the heat dissipation component to efficiently dissipate heat from the heat dissipation component; or as a heat transfer component that contacts a heating object to be heated and a high-temperature component having a higher temperature than the heating object and transfers thermal energy from the high-temperature component to the heating object to efficiently heat the heating object, etc.

[0434] As mentioned above, the shape of the heat conductor 1 is not particularly limited, and may be formed into, for example, Figure 1 The block shape shown, such as Figure 5 As shown in the sheet and so on.

[0435] The following description will focus on a case where the heat conductor 1 is used in contact with at least a portion of the surface of a high-temperature member that is a heat generating element.

[0436] High-temperature components are not particularly limited as long as they are components that are hotter than the surrounding environment. Examples include various electronic components and electrical parts. More specifically, they include computer central processing units (CPUs), graphics processing units (GPUs), power devices, FPGAs, ASICs, smartphone SoCs, embedded DSPs and microcomputers, semiconductor devices such as transistors, laser diodes, light-emitting diodes (LEDs), electroluminescent devices, liquid crystals and other light-emitting devices, CCDs, image sensors (e.g., 8K), switching regulators, motor coils, and printer inkjet heads. Examples of high-temperature components include relays, batteries, transformers, power supply units, bearings, electron guns, vacuum tubes, and high-frequency transmitters. Examples of high-temperature components include tubes or containers containing high-temperature fluids.

[0437] The maximum surface temperature of the high-temperature component is preferably 40°C or higher and 250°C or lower, more preferably 50°C or higher and 200°C or lower, and particularly preferably 60°C or higher and 180°C or lower.

[0438] When the heat conductor 1 is applied to such a high-temperature component, heat conduction and heat dissipation can be performed more appropriately, and the effects of the present invention can be more significantly exhibited.

[0439] Figure 13 The following shows a case where the sheet-shaped heat conductor 1 is applied to a central processing unit.

[0440] The CPU 100 chip (die) is mounted on a substrate 130 on a motherboard 120. Wiring 140 (first cache) is provided on the substrate 130 outside the chip. Wiring 140 is protected by underfill 150, but the underfill 150 is applied only to a width of approximately 1 mm from the perimeter of the chip, leaving a portion of wiring 140 exposed.

[0441] A sheet-like heat conductor 1 is placed and thermally coupled between the central processing unit 100, a high-temperature component that generates heat, and the cooling fins 110, a heat dissipating component. Heat conductor 1 is placed between the central processing unit 100 and the cooling fins 110, for example, while being pressed with a pressure of approximately 0.2 MPa.

[0442] As described above, the thermal conductor 1 is made of a material with excellent thermal conductivity and is also highly flexible, allowing it to adapt well to the shapes of the surfaces of high-temperature components and heat dissipation components. Therefore, even when the surfaces of high-temperature components and heat dissipation components have relatively large irregularities, the thermal conductor 1 can maintain suitable adhesion to these components, maintaining low interfacial thermal resistance and ensuring excellent substantial heat conduction from the high-temperature components to the thermal conductor 1.

[0443] Accordingly, the heat from the central processing unit 100, which is a high-temperature component, can be effectively dissipated, and the occurrence of unpreferable situations such as failure or malfunction of the central processing unit 100 caused by heat can be suppressed, and the product life of the central processing unit 100 can be extended.

[0444] Furthermore, in the thermal conductor 1 of the present invention, the gap 2 is provided to suppress excessive deformation of the thermal conductor 1 when pressed. This can preferably prevent problems such as electrical short circuits in electronic circuits caused by the protruding portion of the pressed thermal conductor 1 coming into contact with the exposed wiring 140.

[0445] For example, the heat conductor 1 may be subjected to step processing on the surface facing the high-temperature component to form the step 200 .

[0446] The step processing can be performed, for example, in accordance with the surface shape of a high-temperature component to which the heat conductor 1 is applied.

[0447] Thus, for example, the heat conductor 1 can be brought into more reliable contact with even a high-temperature component having a complex surface shape, and can be suitably used as a TIM (Thermal Interface Material) for cooling such a component.

[0448] Examples of components having a complex surface shape include CCDs, LEDs, and small sensor modules.

[0449] In addition, for example, when the heat conductor 1 is used to cool multiple high-temperature components (components 210) provided on a substrate (when it is configured to span multiple high-temperature components (components 210)), it is more preferable to apply step processing corresponding to the surface shape of the surface including the multiple high-temperature components on the side facing these high-temperature components.

[0450] Thereby, these multiple high-temperature components can be appropriately cooled simultaneously.

[0451] In addition, step processing such as Figure 14As shown, when the heat conductor 1 is applied to a component having multiple parts, a height difference can be set in such a manner that the heat conductor 1 contacts a part of the parts, for example, a high-temperature component such as an electronic component (component 210), and does not contact another part of the parts, for example, a non-high-temperature component such as a substrate.

[0452] There is no particular limitation on the time of forming the step processing, that is, the step 200. For example, the step 200 may be formed during the manufacturing process of the heat conductor 1, or may be formed after the manufacture of the heat conductor 1 according to the user's needs.

[0453] In addition, if Figure 15 As shown, the heat conductor 1 may have a bottomed recess 70 . In this case, for example, a high-temperature component (not shown) may be installed in the bottomed recess 70 and used.

[0454] The formation timing of the bottomed concave portion 70 is not particularly limited. For example, the bottomed concave portion 70 may be formed during the manufacturing process of the thermal conductor 1 or may be formed by the user after the thermal conductor 1 is manufactured.

[0455] exist Figure 15 In the structure shown, the bottomed recess 70 where the high temperature component is installed has a depth direction equal to Figure 1 The X direction of the heat conductor 1 shown is aligned, but the direction of the bottomed recess 70 is not limited thereto.

[0456] by Figure 15 In the configuration shown, examples of high-temperature components to which the device is applied include micromotors, high-brightness LED units, sensor heating elements, and CCD camera units.

[0457] The outer surface of the thermal conductor 1 , particularly the surface where the thermally conductive portion 10 and the joint portion 20 are exposed, can be brought into contact with a heat dissipation member (not shown).

[0458] This can further improve the heat dissipation efficiency from high-temperature components.

[0459] Since the heat conductor 1 is excellent in flexibility, the inner surface of the bottomed recess 70 can be deformed, and can more appropriately follow the surface shape of the high-temperature component disposed in the bottomed recess 70 , and can fully ensure close adhesion.

[0460] The size of the bottomed recess 70 is not particularly limited, but it is preferred that no component is provided in the bottomed recess 70, and the width of the bottomed recess 70 in its natural state without external force (its diameter when the bottomed recess 70 is circular) is smaller than the width of the component provided in the bottomed recess 70.

[0461] This makes it possible to further improve the adhesion between the heat conductor 1 and the member provided in the bottomed recess 70 , and to more significantly exhibit the aforementioned effects.

[0462] Furthermore, the bottomed concave portion 70 may be a slit, and in particular, may be substantially blocked in a natural state without applying an external force, without providing any member in the bottomed concave portion 70 .

[0463] In addition, if Figure 16 As shown, the heat conductor 1 may also have a hole portion 80 that is a through recessed portion. In this case, for example, a high-temperature component can be inserted into the hole portion 80 for use. Figure 16 , a configuration is shown in which a pipe body 180 serving as a high-temperature component is inserted into the hole 80 .

[0464] By inserting the tube 180 as a high temperature component into the hole 80, for example, when a high temperature fluid HF exists inside the tube 180, not only the tube 180 is cooled, but also the high temperature fluid HF can be efficiently cooled through the tube 180 and the heat conductor 1. Figure 16 In the illustrated configuration, the high-temperature components to be cooled are the tube 180 and the high-temperature fluid HF. In other words, the high-temperature fluid HF that is not in direct contact with the heat conductor 1 can also be efficiently cooled by the heat conductor 1 .

[0465] The formation timing of the hole portion 80 is not particularly limited. For example, the hole portion 80 may be formed during the manufacturing process of the thermal conductor 1 or may be formed by the user after the thermal conductor 1 is manufactured.

[0466] exist Figure 16 The structure shown in the figure has a hole 80 for inserting a high temperature component. Figure 1 The X direction of the heat conductor 1 shown is aligned, but the direction of the hole 80 is not limited to this.

[0467] The outer surface of the thermal conductor 1 , particularly the surface where the thermally conductive portion 10 and the joining portion 20 are exposed, may be brought into contact with a heat dissipation member (not shown).

[0468] This can further improve the heat dissipation efficiency from high-temperature components.

[0469] Since the heat conductor 1 has excellent flexibility, the inner peripheral surface of the hole 80 can be deformed to more appropriately follow the surface shape of the tube 180 passing through the hole 80, and sufficient adhesion can be ensured.

[0470] The size of the hole portion 80 is not particularly limited, but it is more preferred that no component is provided in the hole portion 80, and the width of the hole portion 80 in a natural state without external force applied (its diameter when the hole portion 80 is circular) is smaller than the width of the component inserted into the hole portion 80 (its outer diameter when the component is cylindrical or columnar).

[0471] This can further improve the adhesion between the heat conductor 1 and the member inserted into the hole 80, and more significantly exhibit the aforementioned effects.

[0472] The hole 80 may be a slit, and in particular, may be substantially blocked in a natural state where no member is inserted into the hole 80 and no external force is applied.

[0473] The aforementioned heat conductor of the present invention can also be applied to electronic devices. Such electronic devices include, for example, electronic components and a heat dissipation member or the heat conductor of the present invention as the aforementioned heat transfer member.

[0474] Examples of electronic devices to which the heat conductor of the present invention is applied include small electronic devices.

[0475] Examples of small electronic devices include laptop computers, desktop terminals, mobile communication terminals, mobile phones, smartphones, mobile music players, mobile radios, mobile televisions, digital cameras, video cameras, mobile game consoles, electronic book terminals, and mobile medical devices.

[0476] Because such electronic equipment includes a heat conductor with substantially superior heat conductivity, it can more efficiently dissipate heat from electronic components, which are heat-generating components, and more effectively reduce the risks of reduced device or system life and malfunction. Furthermore, because the heat conductor suppresses excessive deformation when pressed, it can prevent failures caused by short circuits in the wiring of electronic components, for example, and further enhance the reliability of the electronic equipment.

[0477] In particular, in mobile communication terminals supporting fifth-generation mobile communications using higher-frequency electromagnetic waves, the heat generation tends to increase due to the further integration and speed increase of electronic components. Therefore, the heat conductor of the present invention can be suitably applied, thereby achieving the above-mentioned effects particularly significantly.

[0478] As mentioned above, although the preferred embodiment of the present invention was described, the present invention is not limited to these.

[0479] For example, in addition to the aforementioned steps, the method for manufacturing a thermal conductor may further include other steps (pre-processing step, intermediate processing step, post-processing step, etc.).

[0480] In addition, in the method for manufacturing a thermal conductor, the order of at least a portion of the aforementioned steps may be replaced.

[0481] The method for manufacturing a heat conductor according to the present invention may be any of the following methods, but may not simultaneously satisfy the following two conditions: a method for manufacturing a heat conductor comprising a plurality of heat conducting portions and a joint portion for joining the heat conducting portions, the method comprising: a heat conducting portion forming member preparation step of preparing a heat conducting portion forming member for forming the heat conducting portions; and a joint forming composition attachment step of attaching a joint forming composition for forming the joint portion to a surface of the heat conducting portion forming member; the heat conducting portion having a void portion, the heat conducting portion and the joint portion not being present in the void portion; and an area of ​​the heat conducting portion when viewed from a first direction being 80 [cm 2 ], and the area of ​​the heat conductor when viewed from above from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2 ], the heat conductor manufactured by the above-mentioned manufacturing method satisfies the condition of 0.5≤[(S1–S0) / S0]×100≤20; or, a manufacturing method of a heat conductor, the heat conductor comprising a plurality of heat conducting parts and a joint part for joining the above-mentioned heat conducting parts, and the manufacturing method of the heat conductor comprises: a heat conducting part forming member preparation step of preparing a long heat conducting part forming member for forming the above-mentioned heat conducting part; a joint forming composition attaching step of attaching a joint forming composition for forming the above-mentioned joint part to the surface of the above-mentioned heat conducting part forming member; a winding step of winding the above-mentioned heat conducting part forming member to which the above-mentioned joint forming composition is attached on the circumference of a reel in a transverse winding manner to obtain a cylindrical wound body; and a cutting step of cutting the above-mentioned wound body in a direction non-perpendicular to the axial direction of the above-mentioned reel to obtain a cut body.

[0482] More specifically, for example, in a method for manufacturing a heat conductor that satisfies the condition of 0.5 ≤ [(S1 – S0) / S0] × 100 ≤ 20, a method other than transverse winding may be used, for example, by winding the heat conductive portion forming member to which the joint forming composition is attached by flat rolling or the like, or by stacking heat conductive portion forming members of blades to which the joint forming composition is attached to form a laminate, and the method may not include a cutting step.

[0483] Furthermore, the heat conductor of the present invention may be manufactured by any method as long as it is a heat conductor having a plurality of heat conducting portions and a joining portion made of a flexible material and joining the heat conducting portions, has a gap portion in which neither the heat conducting portion nor the joining portion exists, and the value of [(S1 − S0) / S0] × 100 is within a predetermined range.

[0484] In the above description, the heat conductor is mainly described as having a planar rectangular shape. However, the shape of the heat conductor can be appropriately set according to the shape of a member in contact with the heat conductor.

[0485] In addition, in the above description, the heat conducting part and the joint part constituting the heat conductor are mainly described as being planar, but at least a portion of the heat conducting part and the joint part constituting the heat conductor may be non-planar, for example, in the form of a curved surface or a bent surface.

[0486] In addition, the heat conductor may have a configuration other than the aforementioned heat conducting portion, joining portion, and gap portion.

[0487] [Example]

[0488] Hereinafter, the present invention will be described in detail based on Examples and Comparative Examples, but the present invention is not limited thereto.

[0489] In addition, the treatments without particularly showing the temperature conditions were performed at 20°C.

[0490] [4] Manufacturing of thermal conductors

[0491] The heat conductors of each example and each comparative example were manufactured as follows.

[0492] (Example 1)

[0493] First, a long strip of graphite with a thickness of 127 μm and a width of 19 mm, in which flaky graphite is oriented along the thickness direction of the graphite sheet, is prepared as a component for forming a long strip (strip-shaped) heat conduction portion, and a SeRM elastomer of a solvent-free single-liquid elastomer raw material is prepared as a composition for forming a joint portion.

[0494] The graphite sheet used in this example has flaky graphite compacted near its surface and has relatively many voids near the center of the thickness direction of the graphite sheet. The density of the graphite sheet is 1.1 g / cm 3 The in-plane thermal conductivity of the graphite sheet at 20°C, measured using the unsteady hot wire method in accordance with JIS R 2616-2000, was 160 W / (m·K). Furthermore, the graphite sheet used in this example had a strip-shaped structure with irregularities on its main surface, and the maximum height roughness Rz of the graphite sheet, measured using the method in accordance with JIS B 0601-2013, was 70 μm.

[0495] The SeRM elastomer used as a joint-forming composition in this embodiment includes a polyrotaxane and a second polymer, and the polyrotaxane is bonded to the second polymer via a cyclic molecule; the polyrotaxane has: a cyclic molecule, a first polymer having a linear molecular structure and enclosing the cyclic molecule in a string-like manner, and end capping groups arranged near both ends of the first polymer.

[0496] Second, use Figure 8 The apparatus shown here uses a dip coater to apply a joint-forming composition to both surfaces of a heat-conducting portion-forming member. The joint-forming composition applied to the heat-conducting portion-forming member is heated to 50°C and adjusted to a viscosity of 3000 mPa·s.

[0497] Thereafter, a tension of 10 N was applied to the circumference of a winding roll having a diameter of 20 cm and a length of 20 cm, and the heat conductive portion forming member to which the bonding portion forming composition was adhered was transversely wound at a speed of 2 m / min to obtain a wound body.

[0498] At this time, ten heat-conducting section-forming members (heat-conducting section-forming members with the bonding section-forming composition attached) were arranged at equal intervals of 1 mm along the length of the take-up reel. The heat-conducting section-forming members were wound while being tilted 2° relative to the axis of the take-up reel, with the tilt direction reversing (positive and negative) with each roll. The tilt angle of the heat-conducting section-forming members relative to the axis of the take-up reel was kept constant in both the positive and negative directions. Furthermore, the temperature of the heat-conducting section-forming members (heat-conducting section-forming members with the bonding section-forming composition attached) was adjusted to 30°C during traverse winding.

[0499] Next, the wound body is cut using a cutter by inserting a notch parallel to the axial direction of the take-up reel, and then removed from the take-up reel to obtain a cut body. Although the obtained cut body is naturally curved, the curvature of the inner circumference of the cut body, that is, the surface in contact with the take-up reel, is smaller than when in contact with the take-up reel, and the cut body is flatter than the wound body.

[0500] Next, the resulting cut body is sandwiched between two flat plates, heated to 120°C, and pressed at 20 MPa for 1 hour. The area corresponding to the outer circumference of the wound body is in contact with one flat plate, while the area corresponding to the inner circumference of the wound body is in contact with the other flat plate.

[0501] After this, the pressing state is maintained while the heating temperature is raised to 180°C for 12 hours to cure the curable resin material constituting the joint-forming composition, thereby obtaining a thermal conductor. After the thermal conductor obtained in this manner is released from the pressurized state, both surfaces in contact with the plate are flat, and these surfaces are parallel.

[0502] Then, the heat conductor is cut into 1.0 mm thick sections with the slicing direction forming an angle of 30° with the thickness direction of the cut body and parallel to the axial direction of the take-up roll. Then, the sections are cut into 40 mm × 40 mm squares. The two main surfaces are then polished with sandpaper to obtain multiple sections as shown in FIG. Figure 5 The sheet-shaped thermal conductor shown is used for various measurements and evaluations described later.

[0503] The sheet-like heat conductor obtained in this way is as follows Figure 5 As shown, the heat conducting portion and the joint portion are exposed on both main surfaces. The heat conducting portion is made of graphite, and the joint portion is made of a flexible resin material. Furthermore, the heat conducting portion has a gap adjacent to the joint portion, where neither the heat conducting portion nor the joint portion exists. This gap is created by bubbles generated by air trapped between the heat conducting portion-forming member and the joint-forming composition during the winding step, as well as by gases generated during the curing reaction of the SeRM elastomer.

[0504] The heat conductor has a plurality of heat conducting portions arranged in a staggered manner when viewed from above, and at least some of the plurality of heat conducting portions are through-heat conducting portions continuously provided inside the heat conductor and exposed on two parallel surfaces.

[0505] In the thermal conductor, the thickness of the thermally conductive portion formed by the thermally conductive portion forming member was 127 μm, the thickness of the joining portion formed of the resin material was 85 μm, and the interval between adjacent thermally conductive portions was 1 mm.

[0506] The ratio of the heat conducting portion to the heat conductor was 60 volume %, the ratio of the joining portion to the heat conductor was 33 volume %, and the ratio of the void portion to the heat conductor was 7 volume %.

[0507] Next, when the ratio of the heat conducting portion in the heat conductor is VC [volume %], the ratio of the joint portion in the heat conductor is VJ [volume %], and the ratio of the void portion in the heat conductor is VV [volume %], the value of [(VJ + VV) / (VC + VJ + VV)] × 100 is 40.

[0508] In addition, the density of thermal conductors in their natural state is 1.1 g / cm 3 .

[0509] In addition, the surface roughness Ra of both main surfaces of the heat conductor measured by a method in accordance with JIS B 0601-2013 was 1.5 μm.

[0510] (Examples 2 to 6)

[0511] A sheet-shaped heat conductor was produced in the same manner as in Example 1 except that the conditions of the heat conduction portion forming member, the conditions of the bonding portion forming composition, and the winding conditions were as shown in Table 1.

[0512] (Example 7)

[0513] A sheet-shaped heat conductor was produced in the same manner as in Example 1 except that a fiber bundle of mesophase pitch-based carbon fibers was used as the heat conducting portion forming member instead of the graphite sheet and the winding speed was changed.

[0514] The thickness of the carbon fiber bundle used in this embodiment is 100 μm, the width is 19 mm, and the roughness of the carbon fibers constituting the fiber bundle is 8 μm.

[0515] (Comparative Examples 1 and 2)

[0516] A sheet-shaped thermal conductor was produced in the same manner as in Example 1 except that the conditions of the thermally conductive portion forming member and the bonding portion forming composition were changed as shown in Table 1.

[0517] (Comparative Example 3)

[0518] In this comparative example, GRAFOIL (produced by NeoGraf Corporation), which is a commercially available graphite sheet, was cut into a 40 mm×40 mm square and used as the heat conducting sheet.

[0519] That is, the thermal conductor of this comparative example does not have a joining portion.

[0520] The graphite sheet used in this comparative example has a thickness of 127 μm and is made of scaly graphite oriented along the thickness direction of the graphite sheet. The scaly graphite is compacted near the surface of the graphite sheet, and has a relatively large number of voids near the center of the thickness direction of the graphite sheet. The density of the graphite sheet is 1.1 g / cm 3 The thermal conductivity of the graphite sheet in the in-plane direction at 20° C., measured by the unsteady hot line method in accordance with JIS R 2616-2000, was 160 W / (m·K).

[0521] The manufacturing conditions and the configurations of the thermal conductors of the aforementioned Examples and Comparative Examples are summarized in Table 1. Table 1 also shows the values ​​of [(S1-S0) / S0]×100, [(S3-S4) / S3]×100, and [(S1'-S0) / S0]×100 for the following areas: 2 ] is the area of ​​the heat conductor when viewed from the upper side (first direction) of the heat conductor in its natural state; S1 [cm 2 ] is the area of ​​the heat conductor when viewed from the top side (first direction) in a pressed state when pressed at 0.2 MPa from the top side (first direction); S3 [cm 2 ] is the area of ​​the heat conductor when viewed from the side (second direction) of the heat conductor in its natural state; S4 [cm 2 ] is the area of ​​the heat conductor when viewed from the side (second direction) under a pressed state at 0.2 MPa from the upper side (first direction); S1' [cm 2 ] is the area of ​​the heat conductor when viewed from above in the first direction, when pressed with a predetermined pressure from the top side (the first direction) and with a compression rate of 20% in the thickness direction. The values ​​of S3 and S4 are the average of the area viewed from one side of the square (the x-direction) and the area viewed from a direction perpendicular to the side (the y-direction).

[0522] [Table 1]

[0523]

[0524] [5] Evaluation

[0525] The following evaluations were performed on the sheet-shaped thermal conductors of the respective Examples and Comparative Examples obtained as described above.

[0526] [5–1] Thermal conductivity of the substance in the pressed state

[0527] Each heat conductor was shaped into a 10 mm x 10 mm square. The thermal conductivity in the first direction (thickness direction) was measured using a method based on ASTM D5470 while being pressed at 0.2 MPa. The heater was adjusted so that the temperature of the upper and lower surfaces of the heat conductor remained approximately 50°C during the measurement.

[0528] [5–2] Determination of thermal conductivity using the unsteady method

[0529] The thermal conductivity was measured by an unsteady hot line method based on a laser flash method in a state where carbon spray with a diameter of 10 mm was applied to the measurement portion of each heat conductor.

[0530] [5–3] Evaluation of short circuit prevention

[0531] First, prepare a motherboard equipped with a CPU for a large-scale business server.

[0532] The motherboard has a substrate with a CPU chip (die) and wiring (first cache) in a portion of the substrate other than the chip. Part of the wiring is exposed without being covered by the underfill.

[0533] The size of the substrate is 40 mm × 28 mm, the size of the chip is 16 mm × 14 mm, and the thickness of the chip is 0.14 mm.

[0534] Next, a heat conductor adjusted to a rectangular shape of 40 mm x 28 mm was placed on the CPU, and cooling fins were fixed to the heat conductor.

[0535] At this time, the heat conductor disposed between the chip and the cooling fins was pressed at a pressure of 0.2 MPa.

[0536] Afterwards, the power was turned on and an evaluation was performed to determine whether an electrical short circuit occurred in the wiring provided on the substrate due to the protruding portion of the heat conductor.

[0537] ○: No wiring short circuit has occurred.

[0538] ×: A short circuit has occurred in the wiring.

[0539] [5–4] Durability evaluation

[0540] The value of L1 / L0 was determined when the length (thickness) of the heat conductor in the initial state (natural state) in the thickness direction (first direction) was defined as L0 [mm], and the length of the heat conductor in the first direction after 1000 repetitions of pressing at 1.0 MPa from the first direction for one minute, releasing the pressing state, and allowing it to rest for one minute was defined as L1 [mm]. Evaluation was performed based on the following criteria. The larger the value of L1 / L0, the better the durability.

[0541] A: The value of L1 / L0 is greater than or equal to 0.90.

[0542] B: The value of L1 / L0 is greater than or equal to 0.80 and less than 0.90.

[0543] C: The value of L1 / L0 is greater than or equal to 0.70 and less than 0.80.

[0544] D: The value of L1 / L0 is less than 0.70.

[0545] These results are shown in Table 2.

[0546] [Table 2]

[0547] Table 2

[0548]

[0549] As is apparent from Table 2, the thermal conductors of each of the Examples, that is, the thermal conductors of the present invention, all exhibit substantially superior thermal conductivity, suppress excessive deformation during compression, and effectively prevent problems such as short circuits. Furthermore, the thermal conductors of the present invention exhibit excellent durability. In contrast, the thermal conductors of the Comparative Examples failed to achieve satisfactory results.

[0550] [Industrial Applicability]

[0551] The heat conductor of the present invention is a heat conductor comprising a plurality of heat conducting parts and a joint portion made of a flexible material and joining the heat conducting parts, wherein the heat conductor has a gap portion in which the heat conducting parts and the joint portion do not exist. The area of ​​the heat conductor when viewed from above in a first direction is 80 [cm 2 ], and the area of ​​the heat conductor when viewed from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2 ], the condition of 0.5≤[(S1–S0) / S0]×100≤20 is satisfied. Therefore, a heat conductor can be provided that has both the ability to ensure tightness to the contacting member during use and the ability to suppress excessive deformation during compression. In addition, the method for manufacturing a heat conductor of the present invention comprises a plurality of heat conducting parts and a joint part for joining the aforementioned heat conducting parts, and the method for manufacturing a heat conductor comprises: a heat conducting part forming member preparation step for preparing a heat conducting part forming member for forming the aforementioned heat conducting part; and a joint forming composition attaching step for attaching a joint forming composition for forming the aforementioned joint part to the surface of the aforementioned heat conducting part forming member; and the aforementioned heat conductor has a gap portion, in which the aforementioned heat conducting part and the aforementioned joint portion do not exist, and the area of ​​the aforementioned heat conductor when viewed from above from the first direction is set to S0[cm 2 ], and the area of ​​the heat conductor when viewed from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2], the thermal conductor manufactured by the manufacturing method satisfies the condition of 0.5≤[(S1-S0) / S0]×100≤20. Therefore, a method for manufacturing a thermal conductor can be provided that can efficiently manufacture a thermal conductor that simultaneously ensures close adhesion to a contacting member during use and suppresses excessive deformation during compression. Furthermore, the present invention provides a method for manufacturing a heat conductor comprising a plurality of heat conducting portions and a joint portion for joining the heat conducting portions. The method comprises: preparing a heat conducting portion-forming member for forming the heat conducting portions; applying a joint-forming composition for forming the joint portion to the surface of the heat conducting portion-forming member; winding the heat conducting portion-forming member, to which the joint-forming composition is applied, around the circumference of a roll in a transverse winding manner to obtain a cylindrical roll; and slitting the roll in a direction non-perpendicular to the axial direction of the roll to obtain a slit. Thus, a method for manufacturing a heat conductor can be provided that efficiently manufactures a heat conductor that simultaneously ensures close adhesion to contacting members during use and suppresses excessive deformation during compression. Therefore, the heat conductor and the method for manufacturing a heat conductor of the present invention have industrial applicability.

[0552] Description of Reference Numerals

[0553] 1: Heat conductor

[0554] 2: Gap

[0555] 10: Heat conduction part

[0556] 10a: First column

[0557] 10b: Second column

[0558] 10c: Through heat conduction part

[0559] 10': Heat conduction portion forming member

[0560] 20: Joint

[0561] 20': Joint forming composition

[0562] 21: Resin material

[0563] 21': Hardening resin material

[0564] 30: Winding body

[0565] 40: Cut body

[0566] 50: Polyrotaxane

[0567] 51: cyclic molecules

[0568] 52: First polymer

[0569] 53: End-capping group

[0570] 60: Second polymer

[0571] 70: Bottomed concave part

[0572] 80: Hole

[0573] 90: Tablet

[0574] 100: Central processing unit

[0575] 110: Cooling fins

[0576] 120: Motherboard

[0577] 130: Substrate

[0578] 140: Wiring

[0579] 150: Underfill

[0580] 180: Tube body

[0581] 200: step difference

[0582] 210: Component

[0583] FG: flake graphite

[0584] HF: High temperature fluid

[0585] R1: embryonic membrane roll

[0586] R2: Take-up reel

[0587] R3: Guide roller

[0588] M: receiving tank

[0589] t 10 :thickness

[0590] t2: thickness

[0591] w 10 :width

[0592] g 10 :interval

[0593] L0: length

[0594] L1: length

[0595] T1: thickness

[0596] T2: Thickness

[0597] T3: Thickness

[0598] S0: Area

[0599] S1: Area

[0600] S3: Area

[0601] S4: Area

[0602] θ1: angle

[0603] θ2: angle

[0604] θ3: angle

[0605] θ4: angle

[0606] A–A': cutting line

[0607] B–B': cutting line

[0608] C–C': cutting line

[0609] D–D': cutting line

[0610] c: Central axis

[0611] D1: Arrow

[0612] D2: Arrow

[0613] d1: direction

[0614] d2: direction

[0615] e 10 : Extension direction

[0616] g1: gap

[0617] g2: gap

[0618] v: vertical line

[0619] V1: Normal direction.

Claims

1. A heat conductor comprising a plurality of heat conducting portions and a joining portion made of a flexible resin material for joining the heat conducting portions; The resin material is a flexible epoxy resin, a rubber resin, a urethane resin, a silicone resin, a fluororesin, an acrylic resin, or a thermoplastic elastomer, or a resin material comprising a first polymer having a cyclic molecule, a linear molecular structure, and including the cyclic molecule in a string-like manner, a polyrotaxane having end-capping groups provided near both ends of the first polymer, and a second polymer, wherein the polyrotaxane and the second polymer are bonded to each other via the cyclic molecule. The heat conductor has a gap portion, in which the heat conducting portion and the joint portion do not exist; The area of ​​the heat conductor when viewed from the first direction is S0 [cm 2 ], and the area of ​​the heat conductor when viewed from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2 ], the heat conductor satisfies the condition of 0.5≤[(S1–S0) / S0]×100≤20.

2. The thermal conductor according to claim 1, wherein The heat conductor is in the form of a sheet.

3. The thermal conductor according to claim 2, wherein The thickness of the heat conductor is greater than or equal to 0.15 mm and less than or equal to 20 mm.

4. The thermal conductor according to any one of claims 1 to 3, wherein At least a portion of the plurality of heat conducting portions is continuously provided inside the heat conducting body and exposed on two different surfaces of the heat conducting body.

5. The thermal conductor according to any one of claims 1 to 3, wherein The heat conductor has at least one set of parallel surfaces; At least a portion of the plurality of heat conducting portions is a through heat conducting portion, which is continuously arranged inside the heat conducting body and exposed on the two parallel surfaces; An angle formed between a normal direction of the surface and an extending direction of the through-heat conducting portion is greater than or equal to 3° and less than or equal to 45°.

6. The thermal conductor according to any one of claims 1 to 3, wherein The ratio of the heat conducting portion in the heat conductor is greater than or equal to 15 volume % and less than or equal to 80 volume %.

7. The thermal conductor according to any one of claims 1 to 3, wherein The ratio of the joining portion to the thermal conductor is greater than or equal to 15 volume % and less than or equal to 70 volume %.

8. The thermal conductor according to any one of claims 1 to 3, wherein The ratio of the voids in the thermal conductor is greater than or equal to 5 volume % and less than or equal to 65 volume %.

9. The thermal conductor according to any one of claims 1 to 3, wherein When the ratio of the heat conductive portion in the heat conductive body is VC [volume %], the ratio of the joint portion in the heat conductive body is VJ [volume %], and the ratio of the void portion in the heat conductive body is VV [volume %], the heat conductive body satisfies the relationship 25≤[(VJ+VV) / (VC+VJ+VV)]×100≤90.

10. The thermal conductor according to any one of claims 1 to 3, wherein The heat conducting portion is made of a material containing graphite.

11. The thermal conductor according to any one of claims 1 to 3, wherein The heat conducting portion is substantially composed of a single component.

12. The thermal conductor according to any one of claims 1 to 3, wherein The plurality of heat conducting portions are arranged in an island shape when viewed from above in the first direction.

13. The thermal conductor according to claim 12, wherein The plurality of heat conducting portions are arranged in a staggered manner when viewed from above in the first direction.

14. The thermal conductor according to any one of claims 1 to 3, wherein The interval between adjacent heat conducting portions when viewed in plan from the first direction is greater than or equal to 1 μm and less than or equal to 2000 μm.

15. The thermal conductor according to any one of claims 1 to 3, wherein The density of the heat conductor before the pressing state is set to be greater than or equal to 0.6 g / cm 3 and less than or equal to 2.5g / cm 3 .

16. The thermal conductor according to any one of claims 1 to 3, wherein The area of ​​the heat conductor when viewed from a second direction perpendicular to the first direction is S3 [cm 2 ], The area of ​​the heat conductor when viewed from the second direction in the pressed state at 0.2 MPa from the first direction is set to S4 [cm 2 ], the heat conductor satisfies the condition of 5≤[(S3–S4) / S3]×100≤50.

17. The thermal conductor according to any one of claims 1 to 3, wherein When the length of the heat conductor in the initial state in the first direction is defined as L0 [mm], and the length of the heat conductor in the first direction after repeating 1000 times of pressing at 1.0 MPa in the first direction for one minute, releasing the pressing state, and letting it stand for one minute is defined as L1 [mm], the heat conductor satisfies the relationship 0.70 ≤ L1 / L0.

18. The thermal conductor according to any one of claims 1 to 3, wherein A measured value of thermal conductivity in the first direction in a pressed state when pressed at 0.2 MPa from the first direction is greater than or equal to 50 W / (m·K).

19. A method for manufacturing a heat conductor comprising a plurality of heat conducting portions and a joining portion made of a flexible resin material for joining the heat conducting portions; The resin material is a flexible epoxy resin, a rubber resin, a urethane resin, a silicone resin, a fluororesin, an acrylic resin, or a thermoplastic elastomer, or a resin material comprising a first polymer having a cyclic molecule, a linear molecular structure, and including the cyclic molecule in a string-like manner, a polyrotaxane having end-capping groups provided near both ends of the first polymer, and a second polymer, wherein the polyrotaxane and the second polymer are bonded to each other via the cyclic molecule. The method for manufacturing the heat conductor comprises: a heat conducting portion forming member preparing step of preparing a heat conducting portion forming member for forming the heat conducting portion; and a bonding portion forming composition attaching step of attaching the bonding portion forming composition used for forming the bonding portion to the surface of the heat conducting portion forming member; The heat conductor has a gap portion, in which the heat conducting portion and the joint portion do not exist; The area of ​​the heat conductor when viewed from the first direction is S0 [cm 2 ], and the area of ​​the heat conductor when viewed from above from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2 ], the thermal conductor manufactured by the manufacturing method satisfies the condition of 0.5≤[(S1−S0) / S0]×100≤20.

20. The method for manufacturing a thermal conductor according to claim 19, wherein: In the bonding portion forming composition attaching step, air bubbles are contained between the heat conduction portion forming member and the bonding portion forming composition.

21. A method for manufacturing a heat conductor comprising a plurality of heat conducting portions and a joining portion made of a flexible resin material for joining the heat conducting portions; The resin material is a flexible epoxy resin, a rubber resin, a urethane resin, a silicone resin, a fluororesin, an acrylic resin, or a thermoplastic elastomer, or a resin material comprising a first polymer having a cyclic molecule, a linear molecular structure, and including the cyclic molecule in a string-like manner, a polyrotaxane having end-capping groups provided near both ends of the first polymer, and a second polymer, wherein the polyrotaxane and the second polymer are bonded to each other via the cyclic molecule. The method for manufacturing the heat conductor comprises: a heat conducting portion forming member preparation step of preparing a long heat conducting portion forming member for forming the heat conducting portion; a bonding portion forming composition attaching step of attaching the bonding portion forming composition used for forming the bonding portion to the surface of the heat conducting portion forming member; a winding step of winding the heat conducting portion forming member to which the bonding portion forming composition is attached around the circumference of a reel in a transverse winding manner to obtain a cylindrical wound body; as well as a slitting step of slitting the wound body in a direction that is non-perpendicular to the axial direction of the roll to obtain a slit body; The heat conductor has a gap portion, in which the heat conducting portion and the joint portion do not exist; The area of ​​the heat conductor when viewed from the first direction is S0 [cm 2 ], and the area of ​​the heat conductor when viewed from above from the first direction in a pressed state at 0.2 MPa from the first direction is set to S1 [cm 2 ], the thermal conductor manufactured by the manufacturing method satisfies the condition of 0.5≤[(S1−S0) / S0]×100≤20.

22. The method for manufacturing a thermal conductor according to claim 21, wherein: The heat conduction portion forming member is formed in a belt shape having projections and depressions on a main surface.

23. The method for manufacturing a thermal conductor according to claim 21, wherein: The heat conduction portion forming member includes a fiber bundle extending along the longitudinal direction of the heat conduction portion forming member.

24. The method for producing a thermal conductor according to any one of claims 21 to 23, wherein: In the winding step, a plurality of the heat conduction portion forming members to which the bonding portion forming composition is adhered are wound around the circumferential surface of one of the rolls to obtain a single wound body.

25. The method for producing a thermal conductor according to any one of claims 21 to 23, wherein: The aforementioned joint forming composition is a composition containing a curable resin material; The manufacturing method further includes a curing step after the cutting step, wherein the curing step cures the curable resin material contained in the cut body.

26. The method for manufacturing a thermal conductor according to claim 25, wherein: The curable resin material is a material that generates gas during the curing step.

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