JP5340069B2 - Carbon-metal composite and circuit member or heat dissipation member using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon-metal composite having good heat radiation characteristics in which a metal layer with few disconnected portions can be easily formed, a circuit member or a heat radiation member using the carbon-metal composite, a heat radiation composite member provided with the circuit member and the heat radiation member, and an electronic device in which an electronic part is mounted on the circuit member in the heat radiation composite member. <P>SOLUTION: The carbon-metal composite 1 includes a dense substrate 2 mainly composed of carbon and a heat transfer layer 3 mainly composed of copper or aluminum formed on the substrate. The circuit member and the heat radiation member uses the carbon-metal composite 1. The heat radiation composite member is provided with the circuit member on the first principal surface side of an insulating support substrate and the heat radiation member on the second principal surface side opposite to the first principal surface, respectively. In the electronic device, an electronic part is mounted on the circuit member in the heat radiation composite member. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a carbon-metal composite and a circuit member or a heat dissipation member using the carbon-metal composite. Further, a heat dissipation composite member in which a circuit member is provided on one main surface of the insulating support base and a heat dissipation member is provided on the other main surface, and an electronic device in which an electronic component is mounted on the circuit member in the heat dissipation composite member It is about.

  In recent years, as components of semiconductor devices, insulated gate bipolar transistor (IGBT) elements, metal oxide field effect transistor (MOSFET) elements, light emitting diode (LED) elements, freewheeling diode (FWD) elements, giant transistors (GTR) ) Electronic devices in which various electronic components such as semiconductor elements such as elements, sublimation type thermal printer head elements and thermal ink jet printer head elements are mounted on a circuit member of a heat dissipation composite member are used.

  And as a heat radiating composite member provided with a circuit member for mounting electronic components, a copper plate is joined as a circuit member to one main surface of a ceramic substrate which is an insulating support base, and a heat radiating material is bonded to the other main surface. A heat dissipation composite member formed by bonding a copper plate is used as a good heat dissipation member.

  As a substitute for a circuit member and a heat radiating member using a copper plate, a carbon material having features such as excellent thermal conductivity and workability, close to the thermal expansion coefficient of ceramics, and lighter than metal has come to be noticed. Yes.

  As such a carbon material, in Patent Document 1, carbon fibers are substantially oriented in the thickness direction, and the ratio of the thermal conductivity in the thickness direction to the thermal conductivity in the direction perpendicular to the thickness direction is 2 or more. A carbon fiber reinforced carbon composite material having a thermal conductivity in the thickness direction of 3 W / cm · ° C. or higher has been proposed. This carbon fiber reinforced carbon composite material is obtained by impregnating a long fiber of carbon fiber into a thermosetting resin and heating it to obtain a fiber / resin composite, from the thickness direction of the composite material intended for the composite. Cut long, align in one direction so that they are substantially parallel to each other, apply pressure in the direction perpendicular to the length of the fiber, mold and cure the resin, then carbonize, and pitch it Alternatively, it is described that it is obtained by impregnating a thermosetting resin and then carbonizing and optionally graphitizing.

Japanese Patent Laid-Open No. 2-30666

  However, the carbon fiber reinforced carbon composite material proposed in Patent Document 1 has a large thermal conductivity and electric conductivity in the thickness direction, and is effective when used when heat and electric conduction in the thickness direction are required. However, in the manufacturing process of carbon fiber reinforced carbon composite material, voids are likely to remain between adjacent carbon fibers, making it porous, and forming a metal layer on the surface of carbon fiber reinforced carbon composite material to further improve heat dissipation characteristics As a result, intermittent portions frequently occur on the porous surface of the metal layer, and there is a problem that heat dissipation characteristics cannot be further improved.

  The present invention has been devised to solve the above-mentioned problems, and a carbon-metal composite having a good heat dissipation property and a carbon-metal composite that can easily form a metal layer with few intermittent parts and a carbon-metal composite are used. It is an object of the present invention to provide a circuit member or a heat dissipation member. Moreover, it aims at providing the electronic device which mounted the electronic component on the heat dissipation composite member which provided these circuit members and a heat dissipation member, and the circuit member in this heat dissipation composite member.

The carbon-metal composite of the present invention is formed by forming a heat transfer layer mainly composed of copper or aluminum on a dense substrate composed mainly of carbon, and an end portion of the surface of the substrate. and it is characterized in Rukoto that having a sloped surface.

  The carbon-metal composite of the present invention is characterized in that, in the above structure, the base material is impregnated with copper or aluminum.

  The carbon-metal composite of the present invention is characterized in that, in each of the above structures, the base material is made of isotropic graphite.

  In the carbon-metal composite of the present invention, the heat transfer layer is formed on the base material through an intermediate layer mainly composed of chromium, iron, cobalt, or nickel. It is characterized by being.

  Further, in the carbon-metal composite of the present invention, in each of the above structures, a coating layer mainly composed of any one of chromium, iron, cobalt, and nickel is formed on the side surface of the base material. It is a feature.

  Moreover, the carbon-metal composite of the present invention has one type selected from titanium, zirconium, hafnium, and niobium on the side surface of the base material, the main component being one or more of silver and copper on the side surface of the base material. A coating layer containing the above is formed.

  The circuit member and heat radiating member of the present invention are characterized by using any one of the above-described carbon-metal composites of the present invention.

Radiating composite member of the present invention is characterized by comprising a circuit member of the present invention set only the first main surface side of the insulating support base.

The electronic device of the present invention is characterized in that an electronic component is mounted on the circuit member in the heat dissipation composite member of the present invention having the above-described configuration .

According to the carbon-metal composite of the present invention, a heat transfer layer mainly composed of copper or aluminum is formed on a dense substrate mainly composed of carbon . from Rukoto to have a slanted surface at an end portion, the heat transfer layer because fewer portions intermittently, can escape efficiently heat from one main surface to the other main surface side. In addition, the production efficiency of the carbon-metal composite can be increased.

  Moreover, according to the carbon-metal composite of the present invention, when the base material is impregnated with copper or aluminum, heat can be more efficiently released from one main surface side to the other main surface side, Since both copper and aluminum have a lower volume resistivity than carbon, heat generation inside can be reduced, and power loss can be reduced.

  In addition, according to the carbon-metal composite of the present invention, when the base material is made of isotropic graphite, the direction of heat radiation is less likely to be biased in a specific direction than in the case of anisotropic graphite. Can be dispersed to escape.

  Further, according to the carbon-metal composite of the present invention, when the heat transfer layer is formed on the base material via the intermediate layer mainly composed of chromium, iron, cobalt, or nickel, The adhesion of the heat transfer layer to the heat is improved, and heat can be released more efficiently.

  Further, according to the carbon-metal composite of the present invention, when a coating layer mainly composed of any one of chromium, iron, cobalt, and nickel is formed on the side surface of the base material, the carbon-metal composite Even if an electronic component is mounted on a circuit member using a body and this electronic component repeatedly generates heat, the heat transfer layer is constrained by the coating layer at the end thereof, and thus it is difficult to peel off, Since moisture in the air is less likely to enter from the surface surrounding the surface of the substrate, the risk of short circuiting is reduced.

  Moreover, according to the carbon-metal composite of the present invention, the side surface of the substrate contains one or more of silver and copper as a main component, and contains one or more selected from titanium, zirconium, hafnium, and niobium. When the coating layer is formed, a heat-generating component such as an electronic component is mounted on the carbon-metal composite, and even if these components repeat operations, the heat transfer layer is constrained by the coating layer at the end. Therefore, it becomes difficult to peel off, and moisture in the air hardly enters from the surface surrounding the surface of the base material, so that the possibility of a short circuit is reduced.

  Moreover, according to the circuit member of the present invention, since the heat can be efficiently released by using the carbon-metal composite of the present invention, the life of the heat-generating component such as an electronic component can be extended. .

  Further, according to the heat dissipating member of the present invention, by using the carbon-metal composite of the present invention, heat can be released efficiently as in the case of the circuit member. Life can be extended.

Further, according to the heat dissipation composite member of the present invention, the first main surface side of the insulating support base when the circuit member of the present invention is a heat radiating composite member formed by setting only, since it is possible to escape heat efficiently In addition, the life of heat-generating parts such as electronic parts can be extended.

  Further, according to the electronic device of the present invention, since the electronic component is mounted on the circuit member in the heat dissipation composite member of the present invention, even when the electronic device is operating, the electronic component hardly stores heat. Therefore, a suitable electronic device can be obtained.

It is a perspective view which shows an example of embodiment of the carbon-metal composite_body | complex of this invention. It is a perspective view which shows the other example of embodiment of the carbon-metal composite_body | complex of this invention. It is a perspective view which shows the other example of embodiment of the carbon-metal composite_body | complex of this invention. It is a perspective view which shows the other example of embodiment of the carbon-metal composite_body | complex of this invention. It is a perspective view which shows the other example of embodiment of the carbon-metal composite_body | complex of this invention. It is a perspective view which shows the other example of embodiment of the carbon-metal composite_body | complex of this invention. It is a perspective view which shows the other example of embodiment of the carbon-metal composite_body | complex of this invention. An example of embodiment of the thermal radiation composite member of this invention is shown, (a) is a top view, (b) is sectional drawing in the AA 'line of (a), (c) is a bottom view. It is. The other example of embodiment of the thermal radiation composite member of this invention is shown, (a) is a top view, (b) is sectional drawing in the BB 'line of (a), (c) is It is a bottom view. The other example of embodiment of the thermal radiation composite member of this invention is shown, (a) is a top view, (b) is sectional drawing in CC 'line of (a), (c) is It is the D section enlarged view of (b), (d) is a bottom view. The other example of embodiment of the thermal radiation composite member of this invention is shown, (a) is a top view, (b) is sectional drawing in the EE 'line of (a), (c) is It is the F section enlarged view of (b), (d) is a bottom view. The other example of embodiment of the thermal radiation composite member of this invention is shown, (a) is a top view, (b) is sectional drawing in the GG 'line | wire of (a), (c) is It is the H section enlarged view of (b), (d) is a bottom view. The other example of embodiment of the thermal radiation composite member of this invention is shown, (a) is a top view, (b) is sectional drawing in the JJ 'line | wire of (a), (c) is It is the K section enlarged view of (b), (d) is a bottom view. It is a side view which shows typically the curvature of the thermal radiation composite member of this invention. An example of an embodiment of an electronic device of the present invention is shown, (a) is a plan view, (b) is a cross-sectional view taken along line LL ′ of (a), and (c) is a bottom view. is there.

  Hereinafter, examples of embodiments of the carbon-metal composite, the circuit member, the heat radiating member, the heat radiating composite member, and the electronic device of the present invention will be described.

  FIG. 1 is a perspective view showing an example of an embodiment of the carbon-metal composite of the present invention.

  In the carbon-metal composite 1 of the present invention, it is important that the heat transfer layer 3 mainly composed of copper or aluminum is formed on the dense base material 2 mainly composed of carbon. For example, as shown in FIG. 1, the substrate 2 has a rectangular parallelepiped shape, and the heat transfer layer 3 is formed on one main surface of the substrate 2. The dense base material 2 refers to a base material 2 having a relative density of 90% or more and 99% or less. The relative density is a value obtained by dividing the bulk density by the theoretical density in%, and the bulk density may be obtained in accordance with JIS R 1634-1998.

  In the carbon-metal composite 1 of the present invention, the heat transfer layer 3 mainly composed of copper or aluminum is formed on the dense base material 2 mainly composed of carbon. Since the heat layer 3 has few intermittent portions, heat can be efficiently released from one main surface side to the other main surface side. The thermal conductivity in the thickness direction of such a carbon-metal composite 1 is, for example, 240 W / (m · K) or more.

In particular, the thickness t _{1 of} the carbon-metal composite ₁ is 1 mm or more and 5 mm or less, the thickness t _{3 of the} heat transfer layer ₃ is 100 μm or more and 400 μm or less, and the thickness ratio t ₁ / t ₃ is 2.5 or more and 50 or less. It is preferable that

  In addition, the main component in the base material 2 and the heat transfer layer 3 refers to a component that occupies 50% by weight or more with respect to 100% by weight of the component constituting each of the base material 2 or the heat transfer layer 3, and in particular, 70% by weight. % Or more is preferable. The ratio of the main component is the infrared absorption method in the case of carbon, which is the main component of the base material 2, and the fluorescent X-ray analysis method in the case of copper or aluminum, which is the main component of the heat transfer layer 3. Alternatively, it can be obtained by ICP (Inductively Coupled Plasma) emission analysis.

  2-7 is a perspective view which shows the other example of embodiment of the carbon-metal composite_body | complex of this invention, respectively.

  In the carbon-metal composite 1 of the present invention in the example shown in FIG. 2, the heat transfer layers 3 (3 a, 3 b) are formed on both main surfaces of the substrate 2. By adopting such a configuration, it becomes easier for current to flow in the thickness direction of the carbon-metal composite 1, heat generation inside can be reduced, and power loss can be reduced.

In particular, the thickness t _{1 of} the carbon-metal composite ₁ is 1 mm or more and 5 mm or less, the thicknesses t _3a and t _{3b of the} heat transfer layers _3a and _3b are both 100 μm or more and 400 μm or less, and the thickness ratio t ₁ / t It is preferable that _3a and t ₁ / t _3b are both 2.5 or more and 50 or less.

  In the carbon-metal composite 1 of the present invention, it is preferable that the base material 2 is impregnated with copper or aluminum. Although it is dense, the substrate 2 has few voids, but if the voids of the substrate 2 are impregnated with copper or aluminum, heat can be released more efficiently from one main surface side to the other main surface side. In addition, since both copper and aluminum have lower volume resistivity than carbon, heat generation in the inside can be reduced and power loss can be reduced.

  In the carbon-metal composite 1 of the present invention, it is preferable that the substrate 2 is isotropic graphite. When the base material 2 is isotropic graphite, the direction of heat radiation is less likely to be biased in a specific direction than when it is anisotropic graphite, so that heat can be more efficiently dispersed and released.

Here, isotropic graphite refers to graphite having a BAF value (Bacon Anisotropy Factor) of 1.1 or less. The BAF value is obtained by an X-ray diffraction method. For example, the angle (φ) where the intensity (I) of the X-ray diffraction indicated by the Miller index (002) and the C-axis direction of the substrate 2 deviate from the method perpendicular to the surface. ), Which is a value calculated by the following equation (1). The BAF value indicates that the smaller the numerical value, the smaller the anisotropy, and the larger the numerical value, the greater the anisotropy.
BAF = 2∫I (φ) cos ² φsinφdφ / ∫I (φ) sin ³ φdφ (1)
Furthermore, it is more preferable that the surface spacing of the Miller index (002) is 0.34 nm or less, and this surface spacing can also be obtained by the X-ray diffraction method.

  Next, the carbon-metal composite 1 of the example of the present invention shown in FIG. 3 has a heat transfer layer 3 on a substrate 2 through an intermediate layer 4 mainly composed of chromium, iron, cobalt, or nickel. Is formed. By setting it as such a structure, the adhesiveness of the heat-transfer layer 3 with respect to the base material 2 becomes good, and heat can be released more efficiently. The reason for this is not clear, but when the heat transfer layer 3 is formed via the intermediate layer 4, carbon and chromium, iron, cobalt, or nickel are combined on the base material 2 side to form a carbide, Since chromium, iron, cobalt or nickel and copper or aluminum form a solid solution on the heat transfer layer 3 side, adhesion between the base material 2 and the intermediate layer 4 and between the intermediate layer 4 and the heat transfer layer 3 is improved. It is estimated that

The thickness t _{1 of} the carbon-metal composite ₁ is 1 mm or more and 5 mm or less, for example, the thickness t ₄ of the intermediate layer ₄ is 0.5 μm or more and 5 μm or less, and the thickness t _{3 of the} heat transfer layer ₃ is 100 μm or more and 400 μm or less. It is.

Next, the carbon-metal composite 1 of the example of the present invention shown in FIG. 4 has inclined surfaces 2 a, 2 b, 2 c, 2 d at the end of the surface of the substrate 2. When the inclined surface 2a, 2b, 2c, 2d is provided at the end of the surface of the base material 2, it is adjacent to each other after being formed into a strip shape or the like in order to obtain a plurality of carbon-metal composites 1 of the present invention. Since the carbon-metal composite body 1 of the present invention can be easily obtained by cutting the grooves formed by the inclined surfaces of the carbon-metal composite body 1, the production efficiency can be increased. The angles θ _2a , θ _2b , θ _2c , and θ _2d of the inclined surfaces 2a, 2b, 2c, and 2d with respect to the surface of the substrate 2 are preferably 45 ° or more and 80 ° or less. In addition, the base material 2 may be provided with inclined surfaces 2a and 2b only at both ends of the upper surface.

Next, in the carbon-metal composite body 1 of the example of the present invention shown in FIG. 5, the end of the surface of the base material 2 is formed in a step shape. Thus, in order to obtain a plurality of the carbon-metal composites 1 of the present invention when the step 2e, 2f, 2g, 2h is provided and the end of the surface of the substrate 2 is formed in a step shape. Since the carbon-metal composite body 1 of the present invention can be easily obtained by cutting the stepped portion thinner than the thickness of the carbon-metal composite body 1 after making it into a strip shape or the like, the production efficiency is improved. Can be high. The ratios h _2e / t ₁ , h _2f / t ₁ , h _2g / t ₁ , h _2h / t ₁ of the steps h _2e , h _2f , h _2g , and h _{2h to} the thickness t ₁ of the carbon-metal composite ₁ are In any case, it is preferably 0.1 or more and 0.3 or less.

  In addition, the carbon-metal composite 1 having an inclined surface at the end of the surface of the base 2 or the step of the end of the surface of the base 2 being used in a stepwise manner. In the heat dissipation composite member provided with the circuit member and the heat dissipation member, since there is a portion that is not restrained on the side surface on the side of the support base where the circuit member or the heat dissipation member is arranged, the stress remaining on the side surface is relieved and the heat history is transferred to the support base. Even if added, cracks are less likely to occur in the support substrate, and the circuit member and the heat dissipation member are less likely to be peeled off from the support substrate, so that the reliability of the heat dissipation composite member can be improved.

  Next, the carbon-metal composite body 1 of the example of the present invention shown in FIGS. 6 and 7 is made of any one of chromium, iron, cobalt, and nickel on the side surface of the base material 2 of the example shown in FIGS. It is preferable that the coating layer 5 mainly composed of one kind is formed. When such a coating layer 5 is formed, even if an electronic component is mounted on a circuit member using the carbon-metal composite 1, and the electronic component repeatedly generates heat, the heat transfer layer 3a, Since 3b is restrained by the coating layer 5 at the end thereof, it becomes difficult to peel off, and moisture in the air hardly enters from the side surface of the substrate 2, so that the possibility of short circuit is reduced. In addition, the side surface of the base material 2 refers to a surface other than the main surface of the base material 2 forming the heat transfer layer 3, and includes not only the side surfaces 2i and 2j but also the inclined surfaces 2a, 2b, 2c and 2d and the stepped portion 2e. , 2f, 2g, 2h.

  In addition, the carbon-metal composite 1 of the present invention is replaced with a coating layer 5 mainly composed of any one of chromium, iron, cobalt, and nickel. The coating layer 5 which has 1 or more types as a main component and contains 1 or more types selected from titanium, zirconium, hafnium, and niobium may be formed. Even when the coating layer 5 is formed, even if an electronic component is mounted on the circuit member using the carbon-metal composite 1 and the electronic component repeatedly generates heat, the heat transfer layer Since 3a and 3b are restrained by the coating layer 5 at their end portions, they are difficult to peel off, and moisture in the air is difficult to enter from the side surface of the base material 2, thereby reducing the possibility of short circuit.

  In this coating layer 5, for example, at least one selected from titanium, zirconium, hafnium, and niobium is 1% by mass to 5% by mass, copper is 15% by mass to 25% by mass, and the remainder is made of silver. The thickness is preferably 10 μm or more and 30 μm or less.

  Incidentally, in the carbon-metal composite 1 of the present invention shown in FIGS. 1 to 7, the heat transfer layer 3 is preferably made of any one of oxygen-free copper, tough pitch copper, and phosphorous deoxidized copper. In particular, the higher the copper content, the lower the electrical resistance and the higher the thermal conductivity, so that the oxygen content of copper is 99.995% by mass or more, which is linear crystalline oxygen-free copper, single-crystal high-purity oxygen-free copper Or vacuum-dissolved copper. For this reason, the carbon-metal composite in which the heat transfer layer 3 made of any one of linear crystalline oxygen-free copper having a copper content of 99.995% by mass or more, single-crystal high-purity oxygen-free copper, and vacuum-dissolved copper is formed. Even when an electronic component is mounted on a circuit member using the body 1 and the electronic component repeatedly generates heat, the carbon-metal composite 1 is excellent in heat dissipation characteristics, so that power loss can be reduced. Further, the higher the copper content, the lower the yield stress and the easier the plastic deformation at high temperatures. Therefore, when joining various members such as a circuit member or a heat radiating member using the carbon-metal composite 1, Bonding strength is increased, and higher reliability can be ensured.

  The circuit member of the present invention preferably uses the carbon-metal composite 1 of the present invention as described above. Such a circuit member is a member provided with a circuit formed by patterning the carbon-metal composite 1 in advance by a method such as pressing, etching, and wire processing. Even if a component that generates heat such as an electronic component is mounted on the circuit member using the carbon-metal composite 1 of the present invention and these components repeatedly generate heat, the heat can be efficiently released, It is possible to extend the life of parts that generate heat, such as parts.

  Moreover, it is suitable for the heat radiating member of this invention to use the carbon-metal composite 1 of this invention as mentioned above. Such a heat radiating member is a member that is directly or indirectly joined to a component that generates heat and promotes heat radiation from the component that generates heat. When a component such as an electronic component that generates heat is mounted on a heat dissipation member using the carbon-metal composite 1 of the present invention via a circuit member, the heat can be efficiently released, so that the electronic component or the like It is possible to extend the life of the parts that generate heat.

  FIG. 8 shows an example of an embodiment of the heat dissipation composite member of the present invention, (a) is a plan view, (b) is a cross-sectional view taken along line AA ′ of (a), (c ) Is a bottom view.

  The heat dissipation composite member 6 of the present invention of the example shown in FIG. 8 has a circuit member 8a using the carbon-metal composite 1 of the present invention on the first main surface side of the insulating support base 7, and the first main surface. Each heat dissipating member 9b is provided on the opposing second main surface side. Here, the heat dissipation member 9b is composed of a composite in which copper is impregnated with silicon carbide, a copper-diamond sintered body, a composite in which copper is impregnated with carbon, a copper-molybdenum alloy, a copper-tungsten alloy, copper and a copper alloy. It is suitable to consist of either of these. In particular, the heat radiating member 9b more preferably contains 99.96 mass% or more of copper when copper is the main component.

  FIG. 9 shows another example of the embodiment of the heat dissipation composite member of the present invention, (a) is a plan view, (b) is a sectional view taken along line BB ′ of (a), (C) is a bottom view.

  The heat dissipation composite member 6 of the present invention shown in FIG. 9 has the circuit member 8b on the first main surface side of the insulating support base 7 and the heat dissipation of the present invention on the second main surface side facing the first main surface. Each member 9a is provided. Here, the circuit member 8b is preferably made of either copper or an alloy thereof or aluminum or an alloy thereof, and more preferably contains 99.96% by mass or more of copper or aluminum.

  If the circuit member 8b and the heat radiating member 9b are made of any of the above-described materials having high thermal conductivity, heat from electronic components (not shown) such as semiconductor elements mounted on the circuit member 8b spreads immediately. The heat dissipation characteristics of the heat dissipation composite member 6 can be enhanced.

The volume specific resistances of the circuit members 8a and 8b and the heat radiating members 9a and 9b are preferably 5 × 10 ⁻⁸ Ω · m or less, particularly 3 × 10 ⁻⁸ Ω · m or less.

  In particular, the heat dissipation composite member 6 of the present invention is preferably provided with a circuit member 8a using the carbon-metal composite 1 of the present invention and a heat dissipation member 9a using the carbon-metal composite 1 of the present invention. is there. In this case, since the thermal expansion coefficient of the insulating support base 7 and the thermal expansion coefficient of carbon forming the carbon-metal composite 1 are approximated, the support base 7, the circuit member 8a, and the heat dissipation member 9a. Since the residual stress which generate | occur | produces in the joining process with can be suppressed, the reliability of the thermal radiation composite member 6 can be improved.

  The support base 7 constituting the heat dissipation composite member 6 of the present invention has a rectangular parallelepiped shape. For example, the length (X direction shown in FIGS. 8 to 14) is 30 mm or more and 80 mm or less, and the width (FIGS. 8 to 14 is shown). (Y direction shown) is 10 mm or more and 80 mm or less. Although the thickness of the support base 7 varies depending on the application, it is preferable that the thickness is 0.2 mm or more and 1.0 mm or less in order to achieve high durability and high withstand voltage and suppressed thermal resistance. The circuit members 8a and 8b have, for example, a length of 5 mm to 60 mm and a width of 5 mm to 60 mm. The thickness is determined by the magnitude of the current flowing through the circuit members 8a and 8b, the amount of heat generated by the electronic components mounted on the circuit members 8a and 8b, and is, for example, 0.5 mm or more and 5 mm or less. For example, the heat radiation members 9a and 9b have a length of 5 mm to 120 mm and a width of 5 mm to 100 mm. The thickness of the heat dissipating members 9a and 9b is 0.5 mm or more and 5 mm or less, but varies depending on the required heat dissipating characteristics.

  Further, in the heat dissipation composite member 6 of the present invention, the circuit member 8a of the present invention shown in FIG. 10 and the heat dissipation member 9a of the present invention shown in FIG. 11 are shown in FIGS. 10 (c) and 11 (c). As shown in FIG. 1, the first metal layer 10 and the second metal layer 11 are sequentially joined from the support base 7 side, and the first metal layer 10 is composed mainly of at least one of silver and copper. In addition, the second metal layer 11 may contain one or more selected from gold, silver, copper, nickel, cobalt, and aluminum as the main component, containing at least one selected from titanium, zirconium, hafnium, and niobium. Is preferred.

  With such a configuration, when the support base 7 and the circuit member 8a of the present invention or the heat dissipation member 9a of the present invention are joined, both main surfaces of the second metal layer 11 are at a low temperature of 50 ° C. or higher and 100 ° C. or lower. It can be firmly joined. As a result, the residual stress applied to the support base 7 along with this joining becomes smaller than when joining at a high temperature, so that the warp generated in the support base 7 can be reduced. Furthermore, since the circuit member 8a and the heat radiating member 9a can be made thicker by being bonded at a low temperature, it is not necessary to attach a heat sink for further diffusing the heat generated from the electronic components.

  The second metal layer 11 is preferably composed mainly of nickel, more preferably 90% by mass or more, particularly 99% by mass or more. The more nickel is contained in the second metal layer 11, the lower the electrical resistance and the higher the thermal conductivity. Therefore, even if the electronic component is mounted on the heat dissipation composite member 6 and the electronic component is operated, the heat dissipation composite member 6 will dissipate heat. Since the characteristics are excellent, power loss can be reduced. In addition, as the nickel content increases, a dense layer is formed, and voids such as pores are less likely to be generated between the second metal layer 11 and the circuit member 8a, the heat dissipation member 9a, and the first metal layer 10. Become more reliable. In addition, it is preferable that the second metal layer 11 has nickel as a main component because it has high adhesion to silver and copper, which are main components of the first metal layer 10.

  Here, the first metal layer 10 has, for example, a length in the X direction and a Y direction of 2 mm to 76 mm and a thickness of 10 μm to 60 μm. The second metal layer 11 may be approximately the same size as the first metal layer 10.

  In the heat dissipation composite member 6 of the present invention, the first metal layer 10 preferably contains at least one selected from molybdenum, tantalum, osmium, rhenium and tungsten. By including at least one selected from molybdenum, tantalum, osmium, rhenium and tungsten, which is a metal having a high melting point, in the paste for forming the first metal layer 10, the melting point of the paste is increased, and the viscosity is increased. In addition, since it becomes difficult to spread on the support base 7 and the shape of the first metal layer 10 can be adjusted with relatively high accuracy, it occurs between adjacent circuit members 8 when a plurality of circuit members 8 are arranged side by side. The risk of a short circuit can be reduced.

  In the heat dissipation composite member 6 of the present invention, it is preferable that the first metal layer 10 contains at least one selected from indium, zinc and tin. By including at least one selected from indium, zinc and tin, which are metals having a low melting point, in the paste for forming the first metal layer, the melting point is lowered, so that the voids in the first metal layer are reduced. Therefore, the bonding strength between the support base 7 and at least one of the circuit member 8 and the heat radiating member 9 can be increased.

  The insulating support base 7 constituting the heat dissipation composite member 6 of the present invention is, for example, a ceramic mainly composed of at least one of silicon nitride, aluminum oxide, aluminum nitride, zirconium oxide, and beryllium oxide, or aluminum oxide. It consists of ceramics of a compound of zirconium oxide. Here, the compound of aluminum oxide and zirconium oxide contains 20% by mass to 80% by mass of aluminum oxide with respect to the total amount of aluminum oxide and zirconium oxide.

  Among these ceramics, it is preferable that the support base 7 is made of a ceramic mainly composed of silicon nitride or aluminum nitride. Such a ceramic may be a sintered body or a single crystal. When the support base 7 is made of ceramics mainly composed of silicon nitride or aluminum nitride, both have high thermal conductivities of 40 W / (m · K) or more and 150 W / (m · K) or more, respectively. For this reason, it can be set as the thermal radiation composite member 6 with a high thermal radiation characteristic and reliability. When the main component of the support base 7 is silicon nitride, the silicon ratio can be obtained by fluorescent X-ray analysis or ICP emission analysis, and converted into nitride, whereby the silicon nitride ratio can be obtained. Further, when the main component of the support base 7 is aluminum nitride, the aluminum ratio can be obtained by the above method, and the aluminum nitride ratio can be obtained by converting to a nitride.

  In particular, when the support base 7 is made of ceramics whose main component is silicon nitride, it is preferable that silicon nitride is contained at least 80% by mass or more. Other additive components may include erbium oxide, magnesium oxide, silicon oxide, molybdenum oxide, aluminum oxide, and the like.

Further, the mechanical properties of the support base 7 are a three-point bending strength of 500 MPa or more, a Young's modulus of 300 GPa or more, a Vickers hardness (Hv) of 13 GPa or more, and a fracture toughness (K _1C ) of 5 MPam ^1/2 or more. Preferably there is. Thus, when the heat dissipation composite member 6 is configured, it can be used for a long period of time. Moreover, when the mechanical properties are in the above-described range, reliability can be improved, and particularly, creep resistance and durability against heat cycle can be improved.

  As for the three-point bending strength, the first metal layer 10, the second metal layer 11, the circuit member 8 and the heat radiating member 9 are removed from the heat radiating composite member 6 by etching, and then JIS R 1601-2008 (ISO 17565: 2003). (MOD)). However, when the thickness of the support base 7 is thin and the thickness of the test piece cut out from the support base 7 cannot be 3 mm, the thickness of the support base 7 is directly evaluated as the thickness of the test piece. Preferably satisfies the above numerical values.

  In addition, regarding the Young's modulus, after removing the first metal layer 10, the second metal layer 11, the circuit member 8, and the heat radiating member 9 from the heat radiating composite member 6, the ultrasonic pulse defined in JIS R 1602-1995 is used. What is necessary is just to measure according to a law. However, when the thickness of the support base 7 is thin and the thickness of the test piece cut out from the support base 7 cannot be 10 mm, the thickness of the support base 7 is directly evaluated as the thickness of the test piece. It is preferable to satisfy the numerical value.

Vickers hardness (Hv) and fracture toughness (K _1C ) conform to the indenter press-in method (IF method) defined in JIS R 1610-2003 (ISO 14705: 2000 (MOD)) and JIS R 1607-1995, respectively. To measure. In addition, the thickness of the support base 7 is thin, and the thickness of the test piece cut out from the support base 7 is 0.5 mm and 3 mm respectively defined by the JIS R 1610-2003 and JIS R 1607-1995 indenter press-fitting method (IF method). When it is not possible, it is preferable that the thickness of the support base 7 is evaluated as it is as the thickness of the test piece and the result satisfies the above numerical value. However, when the thickness of the support base 7 is so thin that the above-mentioned numerical value cannot be satisfied by evaluating the thickness as it is, the indentation load is changed according to the thickness of the support base 7, and 0.5 mm and What is necessary is just to estimate Vickers hardness (Hv) and fracture toughness (K _1C ) at 3 mm by simulation.

Further, the electrical characteristics of the support base 7 is volume resistivity at room temperature 10 ¹² Ω · m or more and 300 ° C. at ¹⁰ 10 Ω · m or more. Since the support base 7 has these electrical characteristics, current leakage from the circuit member 8 side to the heat dissipation member 9 side can be suppressed during operation of the electronic component mounted on the circuit member 8. Therefore, power loss is not generated and malfunction of the electronic device can be reduced.

  In the heat dissipation composite member 6 of the present invention, it is preferable that at least a part of the end surface of the first metal layer 10 is located outside the end surfaces of the circuit member 8 or the heat dissipation member 9. In the heat dissipation composite member 6 of the present invention shown in FIG. 12, the end surfaces in the X direction of the first metal layer 10 are located outside the end surfaces of the circuit member 8 and the heat dissipation member 9. Even if the heat history is applied to the support base 7 in the heat dissipation composite member 6 having such a configuration, the thermal stress generated by the difference in thermal expansion coefficient between the circuit member 8 and the heat dissipation member 9 and the support base 7 is the first. Since it becomes easy to disperse | distribute to the metal layer 10, it becomes difficult to generate | occur | produce a crack in the support base body 7, and can improve reliability.

  Although not shown, each end surface in the Y direction of the first metal layer 10 may be located outside the respective end surfaces of the circuit member 8 and the heat dissipation member 9. Further, the end surfaces of the first metal layer 10 in the X direction and the Y direction may be located outside the end surfaces of the circuit member 8 and the heat dissipation member 9, respectively.

  Further, in the heat dissipation composite member 6 of the present invention, as shown in FIG. 13, the end surfaces in the X direction of the first metal layer 10 are positioned outside the end surfaces of the circuit member 8 and the heat dissipation member 9, respectively. The heat dissipating member 9 is made larger. In the heat dissipation composite member 6 of the example shown in FIG. 13, even when the thermal history is applied to the support base 7, the thermal stress generated by the difference in the thermal expansion coefficient between the circuit member 8 and the heat dissipation member 9 and the support base 7 is the first. Since it becomes easy to disperse | distribute to 1 metal layer 10, it becomes difficult to generate | occur | produce a crack in the support base body 7, and can improve reliability. Furthermore, by making the heat radiating member 9 larger than the circuit member 8, it is possible to efficiently diffuse the heat generated by electronic components such as semiconductor elements mounted on the circuit member 8.

Further, in the heat dissipation composite member 6 of the present invention, the warp with respect to the long side of the second main surface of the support base 7 is 0.3% or less, and this warp is preferably convex toward the heat dissipating member 9. . When a heat sink (not shown) for further diffusing heat is attached to the second main surface side where the heat dissipating member 9 is provided, the contact area with the heat sink increases and heat easily escapes to the heat sink. The heat dissipation characteristics can be further improved. Here, the warp, as shown in FIG. 14, it is that the difference between H ₁ of the highest portion from the lower portion of the first major surface of the support base 7, is measured by a surface roughness meter or a laser displacement meter be able to.

  Next, the electronic device S of the present invention of the example shown in FIG. 15 has one or more electronic components 21 and 22 such as semiconductor elements mounted on the circuit member 8 of the heat dissipation composite member 6 of the present invention. These electronic components 21 and 22 are electrically connected to each other by a conductor (not shown).

  Further, as in the example shown in FIG. 15, it is preferable that the circuit member 8 and the heat radiating member 9 are divided and arranged in a plurality of rows and a plurality of columns, respectively, in plan view. As described above, the circuit member 8 and the heat radiating member 9 are arranged in a plurality of rows and a plurality of columns in a plan view, so that the same number of circuit members 8 are arranged in one row or one column in the heat radiating composite member 6. In comparison, since the support base 7 can be formed into a square or a rectangle close to a square in plan view, warping of the heat dissipation composite member 6 is easily suppressed. Furthermore, since the thermal expansion coefficient of the ceramic forming the support base 7 and the thermal expansion coefficient of carbon forming the carbon-metal composite 1 are approximated, the support base 7, the circuit member 8, and the heat radiating member 9 Since the residual stress which generate | occur | produces in this joining process can be suppressed, the reliability of the thermal radiation composite member 6 can also be improved.

  Next, an example of a method for producing the carbon-metal composite 1 of the present invention will be described.

  On the dense substrate 2 prepared in advance, for example, a liquid phase growth method such as an electrolytic plating method and an electroless plating method, a chemical vapor deposition method such as vapor deposition, a flame spraying method, an electric spraying method, etc. By forming the heat transfer layer 3 mainly composed of copper or aluminum and having a thickness of 100 μm or more and 200 μm or less, preferably 120 μm or more and 180 μm or less by a thermal spraying method or the like, the example of the present invention as shown in FIGS. A carbon-metal composite 1 can be obtained.

  In addition, it is suitable for the base material 2 prepared beforehand to be impregnated with copper or aluminum. In order to obtain the base material 2 containing copper or aluminum, first, carbon powder having an average particle diameter of 15 to 25 μm is blended as an aggregate, and tar pitch or coal tar is blended as a binder. Using a double-arm kneader, heat knead at 150 to 300 ° C. to make a clay. Next, using a pulverizer, the clay is pulverized to a powder so that the average particle size is 10 to 300 μm. Then, the powder obtained by pulverization by the dry press method is filled in a mold and pressed to form a molded body. The pressure at this time is, for example, 50 to 200 MPa. Subsequent firing is performed in a non-oxidizing atmosphere using nitrogen gas or an inert gas or in a reducing atmosphere with carbon powder packed around the compact, and the temperature is set to 800 to 1000 ° C., and the holding time is set to 5 to 400 hours. Firing to make a sintered body. Further, the graphitization may proceed at a high temperature of 1000 ° C. or higher.

  Next, the sintered body is put into a container for impregnating the metal, and after reducing the pressure in the container to 1330 Pa or less, the sintered body is immersed in each molten metal of copper or aluminum, and nitrogen gas is used. The substrate 2 impregnated with copper or aluminum can be obtained by pressurizing and impregnating at 0.49 to 0.98 MPa. Moreover, it is suitable even if the base material 2 consists of isotropic graphite.

  Moreover, the formation method of the heat transfer layer 3 is not particularly limited, but the formation by the plating method is preferable from the viewpoint of the smoothness of the surface of the heat transfer layer 3 and the economical efficiency. Either electrolytic plating or electroless plating may be used, and these techniques may be used in combination.

  Furthermore, in order to increase the smoothness of the surface of the heat transfer layer 3, it is preferable to make the surface of the substrate 2 as smooth as possible. It is preferable that the surface of the base material 2 has an arithmetic average height Ra defined by JIS B 0601-2001 (ISO 4287: 1997 (IDT)) of 50 μm or less in advance.

  Further, before forming the copper layer 3, the intermediate layer 4 mainly composed of chromium, iron, cobalt, or nickel is formed on the substrate 2 by a liquid phase growth method such as an electrolytic plating method or an electroless plating method. May be formed. The thickness of the intermediate layer 4 is preferably 0.5 μm or more and 5 μm or less.

  An example of the liquid phase growth method used for forming the heat transfer layer 3 or the intermediate layer 4 described above is shown below.

  First, as a pretreatment, the substrate 2 is sequentially subjected to ultrasonic cleaning with an organic solvent, cleaning with an acid, and washing with water to remove adhering dust.

  In the case of using the electroless plating method, after the above-described pretreatment, a treatment for generating fine particles on the surface of the base material 2 as a nucleus for forming the heat transfer layer 3 or the intermediate layer 4 (for example, (Processing for attaching palladium as a catalyst to the substrate 2). After performing this process, the base material 2 is washed with water. Thereafter, the carbon-metal composite 1 can be obtained by dipping in a plating solution containing a predetermined metal salt and a reducing agent. When the electroless plating method is used, the plating solution penetrates into the inside of the base material 2 through the pores in the base material 2, so that a high anchor effect is obtained and the heat transfer layer 3 or the intermediate layer 4 is hardly peeled off. .

  In the case of using the electrolytic plating method, after the pretreatment described above, the substrate 2 is energized in an electrolytic solution containing a predetermined metal salt, and the heat transfer layer 3 or the intermediate layer 4 is formed on the surface of the substrate 2. That's fine. When the electroplating method is used, since there is little mixing of the chemical into the heat transfer layer 3 or the intermediate layer 4, the layer can be made tougher than the heat transfer layer 3 or the intermediate layer 4 obtained by the electroless plating method. .

  In addition, when the surface roughness of the heat transfer layer 3 or the intermediate layer 4 is large, processing such as polishing may be performed to increase the surface smoothness. The arithmetic average height Ra defined by JIS B 0601-2001 (ISO 4287: 1997 (IDT)) on the surface of the heat transfer layer 3 or the intermediate layer 4 is preferably 100 nm or less.

  Next, another example of the method for producing the carbon-metal composite 1 of the present invention will be described.

  First, the heat transfer layer 3 and, if necessary, the intermediate layer 4 are formed on the strip-shaped substrate by the manufacturing method as described above. Next, grooves having a triangular or rectangular shape when viewed from the front are formed at predetermined intervals on the surface of the strip-shaped substrate. By cutting along these grooves, the carbon-metal composite 1 of the present invention shown in FIG. 4 or 5 can be obtained.

  Here, in order to obtain the carbon-metal composite 1 of the present invention shown in FIG. 6 or FIG. 7, after cutting the strip-shaped base material along each groove, the side surfaces 2i, 2j, the inclined surfaces 2a, 2b, A silver (Ag) -copper (Cu) based paste containing one or more selected from titanium, zirconium, hafnium and niobium on the side surface including 2c, 2d and steps 2e, 2f, 2g, 2h, etc. It may be applied by any one of printing method, roll coater method, brush coating method and the like. After applying this paste, the carbon-metal composite body 1 of the present invention shown in FIG. 6 or 7 in which the coating layer 5 is formed can be obtained by heat treatment at 800 ° C. or more and 900 ° C. or less.

  Next, an example of the manufacturing method of the heat dissipation composite member 6 of the present invention will be described.

  In order to obtain the heat dissipation composite member 6 of the present invention shown in FIG. 8, first, the length in the X direction is 30 mm or more and 80 mm or less, the length in the Y direction is 10 mm or more and 80 mm or less, and the thickness is 0.2 mm. The insulating property is 1.0 mm or less and is made of a ceramic mainly composed of at least one of silicon nitride, aluminum oxide, aluminum nitride, zirconium oxide, and beryllium oxide, or a ceramic made of a compound of aluminum oxide and zirconium oxide. A support base 7 is prepared. Next, a circuit member 8 a using the carbon-metal composite 1 of the present invention is disposed on the first main surface side of the support base 7. Also, any of copper, copper alloy, a composite in which copper is impregnated with silicon carbide, a copper-diamond sintered body, a composite in which copper is impregnated with carbon, a copper-molybdenum alloy, and a copper-tungsten alloy are provided on the second main surface side. A heat dissipating member 9b made of the above is disposed. Then, by heat treatment at 250 ° C. or more and 700 ° C. or less, the circuit member 8a and the heat radiating member 9b are directly joined to the support base 7, and the heat radiating composite member 6 of the present invention shown in FIG. 8 can be obtained.

  In order to obtain the heat dissipation composite member 6 of the present invention shown in FIG. 9, first, a support base 7 having the above-described size and material is prepared. Next, a circuit member 8b made of either copper or an alloy thereof or aluminum or an alloy thereof is disposed on the first main surface side of the support base 7. Moreover, the heat radiating member 9a using the carbon-metal composite 1 of the present invention is disposed on the second main surface side. Then, by heat treatment at 250 ° C. or higher and 700 ° C. or lower, the circuit member 8b and the heat radiating member 9a are directly joined to the support base 7, and the heat radiating composite member 6 of the present invention shown in FIG. 9 can be obtained.

  In addition, the circuit member 8a using the carbon-metal composite 1 of the present invention is disposed on the first main surface side of the support base 7, and heat dissipation using the carbon-metal composite 1 of the present invention on the second main surface side. It goes without saying that the heat dissipating composite member 6 of the present invention having the circuit member 8a and the heat dissipating member 9a of the present invention can be obtained by disposing the member 9a and performing heat treatment at 250 ° C. or higher and 700 ° C. or lower.

  Further, in order to obtain the heat dissipation composite member 6 of the present invention of the example shown in FIGS. 10 and 11, first, a support base 7 having the above-described size and components is prepared. Next, a silver (Ag) -copper (Cu) alloy paste containing at least one selected from titanium, zirconium, hafnium and niobium is applied to both main surfaces of the support substrate 7 by a screen printing method, a roll coater. Apply either by brushing or brushing. Thereafter, the first metal layer 10 is formed by heating at 800 ° C. or more and 900 ° C. or less.

  When the first metal layer 10 contains molybdenum, it contains at least one selected from titanium, zirconium, hafnium and niobium and at least one selected from molybdenum, tantalum, osmium, rhenium and tungsten. After the silver (Ag) -copper (Cu) alloy paste is applied by any of the methods described above, the first metal layer 10 may be formed by heating at 800 ° C. or more and 900 ° C. or less.

  Next, on the first metal layer 10, the main component is selected from gold, silver, copper, nickel, cobalt and aluminum by any method selected from sputtering, vacuum deposition and electroless plating. The second metal layer 11 containing the above is formed.

  Then, the circuit member 8a is disposed on the first main surface side of the support base 7 and the heat dissipating member 9b is disposed on the second main surface side, respectively, and heat-treated at 50 ° C. or higher and 100 ° C. or lower, whereby the present invention shown in FIG. The heat dissipation composite member 6 can be obtained.

  Further, the circuit member 8b is disposed on the first main surface side of the support base 7 and the heat radiating member 9a is disposed on the second main surface side, respectively, and heat-treated at 50 ° C. or higher and 100 ° C. or lower, so that the book shown in FIG. The heat dissipation composite member 6 of the invention can be obtained.

  The thermal stress generated by such heat treatment is absorbed by the second metal layer 11 and becomes smaller, so that the circuit member 8 and the heat radiating member 9 can be made thicker together. The heat radiating composite member 6 in which the circuit member 8 and the heat radiating member 9 are thickened can improve the heat radiating characteristics, and in some cases, it is not necessary to attach a heat sink.

  Here, in order to prevent the reaction layer from substantially existing between the first metal layer 10 and the second metal layer 11, the purity of the metal forming the second metal layer 11 is 99.9% by mass or more. A metal may be used.

  In order to obtain the heat dissipation composite member 6 of the example of the present invention shown in FIGS. 12 and 13, silver containing one or more selected from titanium, zirconium, hafnium and niobium on both main surfaces of the support base 7 ( The paste of Ag) -copper (Cu) alloy is applied by any of the methods described above so that at least a part of the end surface of the first metal layer 10 is located outside the respective end surfaces of the circuit member 8 or the heat dissipation member 9. You can do it.

  Further, in order to obtain the heat dissipation composite member 6 of the present invention of the example shown in FIG. 14, after the first metal layer 10 and the second metal layer 11 are formed by the above-described method, the circuit member 8 and the heat dissipation member 9 are planarized. Visually, it may be divided into a plurality of rows and a plurality of columns and heat-treated at 50 ° C. or higher and 100 ° C. or lower.

  Further, the electronic device of the present invention has the heat dissipation characteristics because the electronic components 21 and 22 are mounted on the circuit member 8 in the heat dissipation composite member 6 having a high heat dissipation characteristic like the electronic device S of the example shown in FIG. The electronic device S can be made high.

  As described above, since the heat dissipation composite member 6 of the present invention has high heat dissipation characteristics as described above, an insulated gate bipolar transistor (IGBT) element, a metal oxide field effect transistor (MOSFET) element, a light emitting diode (LED) element, and a free wheel. The heat generated by various electronic components such as semiconductor elements such as ring diode (FWD) elements and giant transistor (GTR) elements, sublimation thermal printer head elements, and thermal ink jet printer head elements is almost reduced over a long period of time. It can be used while dissipating heat well.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

  First, a base material 2 containing 99% by mass of carbon, having a relative density shown in Table 1, a length of 30 mm in both the X direction and the Y direction, and a length of 2 mm in the Z direction was prepared. .

The relative density of the base material 2 shown in Table 1 is a value obtained by dividing the bulk density by the theoretical density of carbon (2.26 kg / m ³ ) in%, and the bulk density is JIS R 1634- Obtained according to 1998.

Next, as in the example shown in FIG. 2, the thicknesses t _3a and t _3b are both 250 μm on both main surfaces of the base material 2 and the heat transfer layer 3 (3a, 3b) is formed by a plating method to obtain a sample No. 3 which is a carbon-metal composite. 1-26 were obtained. Here, each main component of the heat transfer layer 3 was 99% by mass with respect to 100% by mass of the elements constituting the heat transfer layer 3.

  Sample No. 1-4, 6, 7, 9, 10, 12, 13, 15, 16, 18, 19, 21, 22, 24, and 25 are substrates 2 made of isotropic graphite, sample No. 5, 8, 11, 14, 17, 20, 23, and 26 used the base material 2 made of anisotropic graphite. Sample No. For 4, 7, 10, 13, 16, 19, 22, and 25, the base material 2 in which the components of the elements shown in Table 1 were included in advance was used.

  Then, the surface of the heat transfer layer 3a constituting each sample was observed using an optical microscope at a magnification of 50 times. The sample in which the portion where the heat transfer layer 3a was interrupted was observed. And shown in Table 1.

In addition, each sample was measured for each thermal diffusivity α _x , α _z in the X direction and Z direction by a two-dimensional method using a laser flash using a thermal constant measuring apparatus (TC-7000, manufactured by ULVAC-RIKO Co., Ltd.). The specific heat capacity C of the sample was measured by a scanning calorimetry (DSC method) using an ultrasensitive differential scanning calorimeter (DSC-6200, manufactured by Seiko Instruments Inc.), and the bulk density ρ (kg / m of each sample) ³ ) was measured according to JIS R 1634-1998. And the value calculated | required by these methods is substituted to the following formula | equation (2), (3), and each thermal conductivity (kappa) _x (W / (m * K)) in the X direction of each sample and a Z direction. , Κ _z (W / (m · K)) were calculated, and the values are shown in Table 1.
κ _x = α _x · C · ρ (2)
κ _z = α _z · C · ρ (3)
Further, the volume resistivity of each sample was measured by a two-terminal method, and the measured value is shown in Table 1.

As shown in Table 1, Sample No. which is outside the scope of the present invention. 1 and 2, for the relative density of the base material 2 is not a have dense 89%, and intermittent portion is observed in the heat transfer layer 3a, the thermal conductivity kappa _z is low, the volume resistivity Was big. On the other hand, sample no. In Nos. 3 to 26, since the base material 2 was dense, no intermittent portions were observed in the heat transfer layer 3a. High thermal conductivity kappa _z than 1,2, volume resistivity was low.

  Sample No. 2 in which the substrate 2 is made of isotropic graphite, the relative density is 93%, and the main component of the heat transfer layer 3 is aluminum. 3 and 4 are compared, sample No. Since the base material 2 contains aluminum, the thermal conductivity 4 is high. This is because aluminum having a higher thermal conductivity than carbon, which is the main component of the base material 2, is contained. 3, it can be said that heat can be more efficiently released from one main surface side to the other main surface side. This is because sample no. 6, 7, Sample No. 9, 10, sample no. 12, 13, Sample No. 15, 16, Sample No. 18, 19, Sample No. 21, 22, Sample No. The same applies to 24 and 25.

Sample No. 2 in which the relative density of the base material 2 is 93% and the main component of the heat transfer layer 3 is aluminum. 3 and 5 are compared, sample No. 3 uses the base material 2 made of isotropic graphite, sample No. 3 using the base material 2 made of anisotropic graphite. 5 indicates that the difference Δκ between the thermal conductivity κ _x and the thermal conductivity κ _z is small and the direction of heat radiation is not easily biased in a specific direction, so that heat can be released more efficiently. This is because sample no. 6, 8, Sample No. 9, 11, sample no. 12, 14, sample no. 15, 17, sample no. 18, 20, sample no. 21, 23, Sample No. The same applies to 24 and 26.

  Next, a group consisting of isotropic graphite containing 99% by mass of carbon, having a relative density of 93%, a length in both the X and Y directions of 30 mm, and a length in the Z direction of 2 mm. Material 2 was prepared. The relative density of the substrate 2 was determined by the same method as shown in Example 1.

Then, on one main surface of the substrate 2, the major component shown in Table 2, the thickness t ₃ may form a heat transfer layer 3 is a 250 [mu] m, the sample No. 27 and 32 of the carbon-metal composite 1 of the present invention were obtained. Further, the thickness t ₄ of 3 μm is formed on one main surface of the substrate 2, and after forming the main component intermediate layer 4 shown in Table 2 by electrolytic plating, the thickness t _{3 is} passed through the intermediate layer 4. Is 250 μm and the heat transfer layer 3 of the main component shown in Table 2 is formed, and the sample No. 1 as the carbon-metal composite 1 of the present invention is formed. 28-31 and 33-36 were obtained.

  Thereafter, in order to evaluate the adhesion of the heat transfer layer 3 to the base material 2, the length of the heat transfer layer 3 in the Y direction is reduced from 30 mm to 10 mm by etching, and then the peel strength of the heat transfer layer 3 is peeled off. Was measured according to JIS C 6481-1996, and the measured values are shown in Table 2.

  As shown in Table 2, Sample No. Since No. 28 to 31, 33 to 36 are formed with the heat transfer layer 3 through the intermediate layer 4 mainly composed of chromium, iron, cobalt, or nickel, It was found that the peel strength of the heat transfer layer 3 was larger than 27 and 32, and the adhesion of the heat transfer layer 3 to the substrate 2 was high.

  Next, a strip-shaped substrate made of isotropic graphite containing 99% by mass of carbon, having a relative density of 93%, and lengths of 120 mm, 30 mm, and 2 mm in the X, Y, and Z directions, respectively. Material 2 was prepared. The relative density of the substrate 2 was determined by the same method as that shown in Example 1.

Next, the thicknesses t _3a and t _3b are both 250 μm on both main surfaces of the base material 2, and the main heat transfer layers 3 a and 3 b shown in Table 3 are formed by plating. Grooves having a triangular shape when viewed from the front on the surface of the substrate 2 were formed at intervals of 30 mm in the X direction. Each main component of the heat transfer layer 3 is 99% by mass with respect to 100% by mass of the elements constituting the heat transfer layer 3, and each angle θ _2a , θ _{2b of the} inclined surfaces 2a, 2b, 2c, 2d is set. , Θ _2c , and θ _2d are all 70 °.

  The coating layer 5 has a thickness of 10 μm, and is applied to the side surfaces including the inclined surfaces 2a, 2b, 2c, 2d by screen printing using a paste as a component shown in Table 3, and then heat-treated at 850 ° C. Sample No. 38-56 and 58-76 of the carbon-metal composite 1 of the present invention were obtained. Further, the sample No. in which the coating layer 5 is not formed is shown. 37 and 57 of the carbon-metal composite 1 of the present invention were prepared.

These carbon-metal composites 1 were held at a temperature of 110 ° C. for 60 minutes and then allowed to cool, and the mass W ₁ at that time was measured. Thereafter, the carbon-metal composite 1 is immersed in water, ultrasonic waves having a frequency of 28 kHz are applied for 3 minutes and then taken out, held at a temperature of 60 ° C. for 30 minutes, allowed to cool, and the mass W ₂ at that time is calculated. It was measured. And mass increase rate (DELTA) W (%) shown by the following formula | equation (4) was computed, and the value was shown in Table 3.
ΔW = (W ₂ −W ₁ ) / W ₁ × 100 (4)

  As shown in Table 3, Sample No. Nos. 38 to 41 and 58 to 61 have a coating layer 5 mainly composed of any one of chromium, iron, cobalt, and nickel. 42 to 56, 62 to 76 are mainly composed of one or more of silver and copper, and the coating layer 5 containing one or more selected from titanium, zirconium, hafnium and niobium is formed. Sample No. with no coating layer 5 formed thereon. Since the mass increase rate ΔW (%) is lower than 37 and 57, the infiltration of moisture in the air from the side surface of the base material 2 is small, and the heat transfer layer 3 is restrained by the coating layer 5, so it is difficult to peel off. It has been found that since the moisture in the air is less likely to enter from the side surface of the base material 2, the risk of a short circuit can be reduced.

  Next, a group consisting of isotropic graphite containing 99% by mass of carbon, having a relative density of 93%, a length in both the X and Y directions of 30 mm, and a length in the Z direction of 2 mm. Material 2 was prepared. The relative density of the substrate 2 was determined by the same method as that shown in Example 1.

And the thickness _t3a and _t3b are both 250 micrometers on both the main surfaces of the base material 2, Comprising: The main component heat-transfer layer 3 (3a, 3b) shown in Table 4 is formed by the plating method, An inventive carbon-metal composite 1 was obtained.

  Next, an insulative support base 7 having silicon nitride as a main component, the length in the X direction and the Y direction being both 32 mm, and the length in the Z direction being 0.32 mm is prepared. On the main surface, the first metal layer 10 was applied by screen printing using a paste having the components shown in Table 4, and heated at 850 ° C. to form the first metal layer 10.

  And after apply | coating using the electroless-plating method so that it may become the 2nd metal layer 11 of the main component shown in Table 4 on the 1st metal layer 10, it produces previously on the 1st main surface side of the support base 7 first. By disposing the heat-dissipating member 9a, which is the same carbon-metal composite 1 as previously prepared, on the second main surface side of the circuit member 8a that is the carbon-metal composite 1 thus prepared, heat treatment is performed at 80 ° C. Sample No. which is the composite member 6 is used. 77-134 were obtained.

Then, the warp H ₁ measured by a laser displacement meter in the X direction of the first major surface of the support base 7. Further, the maximum length of the first metal layer 10 protruding from the side surface of the circuit member 8a on the line perpendicularly connecting the side surface of the circuit member 8a and the side surface of the support base 7 is measured with an optical microscope at a magnification of 50 times. This maximum length was taken as the overhang length.

Further, occur are measured plan view the area S _v voids, the area of the state voids no between the supporting base 7 and the first metal layer 10 by ultrasonic flaw detection, or support substrate of the circuit member 8a find the ratio _{(= S v / S o ×} 100) to the area S _o of the combined main surface joined to 7, and the porosity. Here, the measurement conditions of the ultrasonic flaw detection method were a flaw detection frequency of 50 MHz, a gain of 30 dB, and a scan pitch of 100 μm. These measurement results are shown in Table 4.

As shown in Table 4, Sample No. 78 to 105 and 107 to 134 are configured such that the circuit member 8a and the heat radiating member 9a are joined to the first metal layer 10 and the second metal layer 11 sequentially from the support base 7 side. Is at least one of silver and copper and contains at least one selected from titanium, zirconium, hafnium and niobium, and the second metal layer 11 is composed mainly of gold, silver, copper, nickel, cobalt And sample No. 1 in which the second metal layer 11 is not formed. Than 77,106, the value of warpage H ₁ in the X direction of the first major surface of the support base 7 is small, it has been found suitable.

  Sample No. In Nos. 92 to 99 and 121 to 128, since the first metal layer 10 contains at least one selected from molybdenum, tantalum, osmium, rhenium and tungsten, the first metal layer 10 does not contain these metals. . The first metal layer 10 from the end face of the circuit member 8a is shorter than 77 to 91, 100 to 120, and 129 to 134, and has a short protrusion length and is difficult to spread on the support base 7, so that the shape of the first metal layer 10 It was found that when the circuit members 8a are arranged side by side, the risk of a short circuit occurring between adjacent circuit members 8a can be reduced.

  Furthermore, sample no. 93 to 95, 122 to 124, since the first metal layer 10 contains at least one selected from indium, zinc, and tin, the configuration up to component 2 of the first metal layer 10 is the same, Sample No. which does not contain at least one selected from indium, zinc and tin 92, sample no. Compared with 121, it was found that the porosity in the first metal layer 10 was low and the bonding strength could be increased.

  Next, a group consisting of isotropic graphite containing 99% by mass of carbon, having a relative density of 93%, a length in both the X and Y directions of 30 mm, and a length in the Z direction of 2 mm. Material 2 was prepared. The relative density of the substrate 2 was determined by the same method as that shown in Example 1.

Then, the heat transfer layers 3a and 3b whose thicknesses t _3a and t _3b are both 250 μm and whose main component is copper are formed on both main surfaces of the base material 2 by plating, so that the carbon- Metal composite 1 was obtained.

  Next, an insulative support base 7 having silicon nitride as a main component, the length in the X direction and the Y direction being both 32 mm, and the length in the Z direction being 0.32 mm is prepared. On the main surface, a paste of silver (Ag) -copper (Cu) alloy containing titanium was applied by screen printing and heated at 850 ° C. to form the first metal layer 10. In applying the paste, the positions of the end faces in the X direction and the Y direction of the first metal layer 10 with respect to the end faces of the circuit member 8a or the heat radiating member 9a after joining the circuit member 8a and the heat radiating member 9a are shown in Table 5. It adjusted so that it might be shown in.

  And after forming the 2nd metal layer 11 which apply | coated the paste which has copper as a main component on the 1st metal layer 10 using the electroless-plating method, it produced previously on the 1st main surface side of the support base 7 first. By disposing the heat-dissipating member 9a, which is the same carbon-metal composite 1 as previously prepared, on the second main surface side of the circuit member 8a that is the carbon-metal composite 1 thus prepared, heat treatment is performed at 80 ° C. Sample No. which is the composite member 6 is used. 135-138 were obtained.

  The cycle of raising the temperature from room temperature to 125 ° C. and holding it for 30 seconds, then lowering the temperature to −45 ° C., holding it for 30 seconds and raising the temperature to room temperature was taken as one cycle. A heat cycle test was conducted on 135-138. For every 100 cycles, the presence or absence of cracks generated in the support substrate 7 was examined by ultrasonic flaw detection, and the number of cycles in which cracks were first confirmed was shown in Table 5. Here, the measurement conditions of the ultrasonic flaw detection method were a flaw detection frequency of 50 MHz, a gain of 30 dB, and a scan pitch of 100 μm.

  In Table 5, the position of the end surface of the first metal layer 10 on the circuit member 8a side is “outside” that is outside the position of the end surface of the circuit member 8a by more than 30 μm. In addition, it is within ± 30 μm with respect to the position of the end face of the circuit member 8a, and “inside” indicates that it is inside of 30 μm with respect to the position of the end face of the circuit member 8a. In addition, an inequality sign “>” in the column of the number of crack generation cycles indicates that no cracks were confirmed even when the number of cycles was exceeded.

  As shown in Table 5, sample no. Since at least a part of the end face of the first metal layer 10 is located outside the respective end faces of the circuit member 8a or the heat radiating member 9a, the circuit members 135 and 136 are not affected even if heat history is applied to the support base 7. Since the thermal stress generated due to the difference in thermal expansion coefficient between 8a and the heat radiating member 9a and the support base 7 is easily dispersed in the first metal layer 10, at least a part of the end surface of the first metal layer 10 is formed. Sample No. which is not located outside the respective end surfaces of the circuit member 8a or the heat radiating member 9a. It was found that the support base 7 is less likely to crack than 137 and 138, so that the reliability is high.

  Next, a group consisting of isotropic graphite containing 99% by mass of carbon, having a relative density of 93%, a length in both the X and Y directions of 30 mm, and a length in the Z direction of 2 mm. Material 2 was prepared. The relative density of the substrate 2 was determined by the same method as that shown in Example 1.

Then, the heat transfer layers 3a and 3b whose thicknesses t _3a and t _3b are both 250 μm and whose main component is copper are formed on both main surfaces of the base material 2 by plating, so that the carbon- Metal composite 1 was obtained.

  Next, an insulative support base 7 having silicon nitride as a main component, the length in the X direction and the Y direction being both 32 mm, and the length in the Z direction being 0.32 mm is prepared. On the main surface, a paste of silver (Ag) -copper (Cu) alloy containing titanium was applied by screen printing and heated at 850 ° C. to form the first metal layer 10.

Then, the warp H ₁ measured by a laser displacement meter in the X direction of the first major surface of the support base 7, shown in Table 6. In addition, the same heat cycle test as the heat cycle test shown in Example 5 was carried out, and the presence or absence of cracks generated in the support substrate 7 was examined by ultrasonic flaw detection every 100 cycles, and the number of cycles in which cracks were first confirmed. Are shown in Table 6. Here, the measurement conditions of the ultrasonic flaw detection method were a flaw detection frequency of 50 MHz, a gain of 30 dB, and a scan pitch of 100 μm.

  As shown in Table 6, Sample No. In 140 and 141, the warp in the X direction of the first main surface of the support base 7 is 0.3% or less, and the warp is convex toward the heat radiating member 9a. Sample No. with warpage to the long side exceeding 0.3% Although the warp of the long side of the first main surface of the 142 and the support base 7 is 0.3% or less, the warp is concave toward the heat radiating member. As compared with 139, cracks are less likely to occur in the support base 7 and it can be said that the reliability is high.

1: carbon-metal composite 2: base material 3: heat transfer layer 4: intermediate layer 5: coating layer 6: heat dissipation composite member 7: support base 8: circuit member 9: heat dissipation member
10: 1st metal layer
11: Second metal layer
21 and 22: Electronic components S: Electronic devices

Claims (6)

On a dense base material mainly composed of carbon, copper or aluminum would be the heat transfer layer is formed as a main component, characterized Rukoto that having a slanted surface at an end portion of the surface of said substrate And a carbon-metal composite.   The carbon-metal composite according to claim 1, wherein the base material is impregnated with copper or aluminum.   The carbon-metal composite according to claim 1 or 2, wherein the substrate is made of isotropic graphite.   4. The heat transfer layer is formed on the base material through an intermediate layer mainly composed of chromium, iron, cobalt, or nickel. The carbon-metal composite as described. The carbon according to any one of claims 1 to 4 , wherein a coating layer mainly comprising any one of chromium, iron, cobalt, and nickel is formed on a side surface of the base material. A metal complex. A coating layer containing one or more of silver and copper as a main component and containing one or more selected from titanium, zirconium, hafnium and niobium is formed on a side surface of the base material. The carbon-metal composite according to any one of claims 1 to 4 .

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