Heat dissipation member and electronic device

Abstract

To provide a heat dissipation member having improved adhesion between a plating layer and a solder resist layer.SOLUTION: A heat dissipation member 10 includes a heat dissipation substrate 30, a plating layer 40 on at least a first surface of the heat dissipation substrate 30, and a solder resist layer 20 having an opening 25 on the plating layer 40, where at least one side surface 21 of an outer side surface 22 of the solder resist layer 20 and an inner side surface 23 of the opening 25 has a forward tapered structure that widens from the solder resist layer 20 toward the heat dissipation substrate 30 in a cross-sectional view in the thickness direction, and a taper angle of the forward tapered structure is 3.00° or more and 6.00° or less according to the following method 1. (Method 1) In the cross-sectional view in the thickness direction, an angle θ formed by a boundary line L between the plating layer 40 and the solder resist layer 20 and a straight line M connecting an end point B of the boundary line L and a point C on the outline of the side surface 21 extending from the end point B at a height H / 2 that is half the thickness H of the solder resist layer 20 is measured, and the angle θ is defined as the taper angle.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a heat dissipation member and an electronic device. [Background technology]

[0002] In recent years, metal-silicon carbide composites have come to be used as heat dissipation materials for power modules in electric vehicles and electric railways, replacing conventional copper. Although the thermal conductivity of metal-silicon carbide composites is lower than that of copper, their thermal expansion coefficient is 6-10 ppm / K, roughly half that of copper (17 ppm / K). As a result, metal-silicon carbide composites tend to be more reliable, as they tend to prevent cracks from occurring in the solder layer that bonds the ceramic circuit board and heat sink that make up the module.

[0003] Aluminum is often used as the metal in metal-silicon carbide composites. For example, Patent Document 1 describes an aluminum-silicon carbide composite obtained by impregnating a porous silicon carbide molded body with an aluminum alloy, with the aim of obtaining an aluminum-silicon carbide composite that has high thermal conductivity, low thermal expansion, and a low specific gravity, wherein the proportion of silicon carbide in the composite is 60% by volume or more, the composite contains 60% by mass or more and 75% by mass or less of silicon carbide having a particle size of 80 μm or more and 800 μm or less, 20% by mass or more and 30% by mass or less of silicon carbide having a particle size of 8 μm or more and less than 80 μm, and 5% by mass or more and 10% by mass or less of silicon carbide having a particle size of less than 8 μm. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-007634 Summary of the Invention [Problem to be solved by the invention]

[0005] The heat dissipation component may have a plating layer on a heat dissipation substrate, and may further have a solder resist layer on the plating layer.

[0006] However, in the heat dissipation member as described above, if the adhesion between the plating layer and the solder resist layer is low, the solder resist layer may peel off from the plating layer. That is, there is a demand for a heat dissipation member with improved adhesion between the plating layer and the solder resist layer.

[0007] The present invention has been made in view of the above circumstances, and provides a heat dissipation member and an electronic device in which the adhesion between the plating layer and the solder resist layer is improved.

[0008] The present inventors conducted extensive research to solve the above problems, and as a result, they found that a heat dissipation component comprising a heat dissipation substrate, a plating layer on at least a first surface of the heat dissipation substrate, and a solder resist layer having an opening on the plating layer, wherein at least one of the outer surface of the solder resist layer and the inner surface of the opening has a forward tapered structure that widens from the solder resist layer toward the heat dissipation substrate in a cross-sectional view in the thickness direction, and the forward tapered structure has a taper angle of 3.00° to 6.00°, can improve adhesion between the plating layer and the solder resist layer, and completed the present invention.

[0009] According to the present invention, there are provided the following heat dissipation member and electronic device.

[0010] [1] A heat dissipation substrate; a plating layer on at least a first surface of the heat dissipation substrate; a solder resist layer having openings on the plating layer, at least one of an outer surface of the solder resist layer and an inner surface of the opening has a forward tapered structure that widens from the solder resist layer toward the heat dissipation substrate when viewed in cross section in the thickness direction; A heat dissipation member according to the following method 1, wherein the taper angle of the forward tapered structure is 3.00° or more and 6.00° or less. (Method 1) In a cross-sectional view in the thickness direction, the angle θ formed by a boundary line L between the plating layer and the solder resist layer, an end point B of the boundary line L, and a straight line M connecting a point C on the outline of the side surface extending from the end point B at a height H / 2, which is half the thickness H of the solder resist layer, is measured and defined as the taper angle. [2] The heat dissipation member according to [1], wherein the solder resist layer has a thickness of 5.0 μm or more and 50.0 μm or less. [3] The heat dissipation member according to [1] or [2], wherein the solder resist layer contains a cured product of an ultraviolet-curable resin composition. [4] The heat dissipation member according to [3], wherein the ultraviolet-curable resin composition contains one or more (meth)acrylic acid ester monomers selected from the group consisting of polyester (meth)acrylate, polyether (meth)acrylate, urethane (meth)acrylate, carbonate (meth)acrylate, and epoxy (meth)acrylate. [5] The ultraviolet-curable resin composition was measured using an E-type viscometer at a temperature of 25°C and a shear rate of 19.2 s -1 The heat dissipation member according to [3] or [4], wherein the viscosity measured under the conditions is 1 Pa·s or more and 150 Pa·s or less. [6] The heat dissipation member according to any one of [1] to [5], wherein the plating layer contains one or more elements selected from the group consisting of Ni, Au, and Ag. [7] The heat dissipation member according to [6], wherein the plating layer includes a Ni plating layer. [8] The heat dissipation member according to any one of [1] to [7], wherein the arithmetic mean roughness Ra of the surface of the plating layer, measured in accordance with JIS B0601:2001 (corresponding international standard: ISO4287), is 0.300 μm or more and 3,000 μm or less. [9] A heat dissipation member according to any one of [1] to [8], wherein the average length Rsm of the roughness curve elements on the surface of the plating layer, measured in accordance with JIS B0601:2001 (corresponding international standard: ISO4287), is 20.0 μm or more and 250.0 μm or less.

[10] The heat dissipation member according to any one of [1] to [9], wherein the thickness of the plating layer is 1 μm or more and 20 μm or less.

[11] The heat dissipation member according to any one of [1] to

[10] , wherein the plating layer is continuously present on the first surface and the side surfaces of the heat dissipation substrate.

[12] The heat dissipation member according to any one of [1] to

[11] , wherein the heat dissipation substrate contains a metal-silicon carbide composite.

[13] The heat dissipation member according to

[12] , wherein the metal-silicon carbide composite contains one or more materials selected from the group consisting of aluminum, aluminum alloys, magnesium, and magnesium alloys in a silicon carbide porous body.

[14] The heat dissipation member according to

[13] , further comprising, at least on the first surface side, a surface metal layer between the heat dissipation substrate and the plating layer, the surface metal layer containing one or more metals selected from the group consisting of aluminum, aluminum alloy, magnesium, and magnesium alloy.

[15] The heat dissipation member according to

[14] , wherein the metal-silicon carbide composite contains aluminum in the silicon carbide porous body, and the surface metal layer contains aluminum.

[16] The heat dissipation member according to any one of [1] to

[15] , which has an average coefficient of thermal expansion from 25°C to 150°C of 1.0 ppm / K or more and 20.0 ppm / K or less.

[17] The heat dissipation member according to any one of [1] to

[16] , which has a thermal conductivity in the thickness direction at 25° C. of 50 W / (m·K) or more.

[18] A heat dissipation member according to any one of [1] to

[17] , a solder layer inside the opening of the heat dissipation member; an insulating substrate on the solder layer; an electronic component on the insulating substrate, The electronic device is configured such that the plating layer in the heat dissipation member and the insulating substrate are solder-connected by the solder layer. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a heat dissipation member and an electronic device in which the adhesion between the plating layer and the solder resist layer is improved. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic plan view showing an example of the structure of the heat dissipation member of the present embodiment. [Figure 2] 1 is a schematic cross-sectional view showing an example of the structure of a heat dissipation member according to an embodiment of the present invention. [Figure 3] 1 is a schematic cross-sectional view showing an example of a forward tapered structure of a solder resist layer according to an embodiment of the present invention; [Figure 4] 1 is a schematic cross-sectional view showing an example of the structure of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are designated by similar reference numerals, and descriptions thereof will be omitted where appropriate. Furthermore, the drawings are schematic diagrams and do not correspond to actual dimensional proportions.

[0014] Unless otherwise specified, the term "approximately" used in this specification means that a range is included taking into consideration manufacturing tolerances, assembly variations, and the like. Unless otherwise specified, for various numerical values ​​(especially measured values) in this specification that may change depending on temperature, values ​​at room temperature (25°C) can be used. In this specification, unless otherwise specified, the symbol "to" indicating a range of values ​​means that the upper and lower limits are included.

[0015] The heat dissipation member of this embodiment includes a heat dissipation substrate, a plating layer on at least a first surface of the heat dissipation substrate, and a solder resist layer having openings on the plating layer. The heat dissipation member of this embodiment will now be described with reference to Fig. 2, which is a schematic cross-sectional view showing an example of the structure of the heat dissipation member of this embodiment. Fig. 2 is a cross-sectional view taken along the line AA in Fig. 1, which is a schematic plan view showing an example of the structure of the heat dissipation member of this embodiment.

[0016] As shown in FIG. 2, the heat dissipation component 10 includes a heat dissipation substrate 30, a plating layer 40 on a first surface of the heat dissipation substrate 30, and a solder resist layer 20 having openings 25 on the plating layer 40. The surface of the opening 25 of the heat dissipation member 10 is a plated layer 40, and by bonding an electronic component to this portion via an insulating substrate, the heat generated by the electronic component can be efficiently dissipated. Furthermore, by bonding other heat dissipation components such as heat dissipation fins or a heat dissipation unit to the second surface of the heat dissipation member 10, the heat generated by the electronic component can be dissipated even more efficiently. Furthermore, by covering the surfaces of the first surface of the heat dissipation member 10 other than the opening 25 with the solder resist layer 20, the electrical insulation between the plating layer 40 and the electronic components joined to the plating layer 40 on the surface of the opening 25 via an insulating substrate is improved.

[0017] In this embodiment, at least one of the outer surface of the solder resist layer and the inner surface of the opening has a forward tapered structure that widens from the solder resist layer toward the heat dissipation substrate when viewed in cross section in the thickness direction, and the taper angle of the forward tapered structure is 3.00° or more and 6.00° or less according to Method 1 below. (Method 1) In a cross-sectional view in the thickness direction, the angle θ formed by a boundary line L between the plating layer and the solder resist layer, an end point B of the boundary line L, and a straight line M connecting a point C on the outline of the side surface extending from the end point B at a height H / 2, which is half the thickness H of the solder resist layer, is measured and defined as the taper angle.

[0018] The forward tapered structure and taper angle of the solder resist layer of this embodiment will now be described with reference to Fig. 2 and Fig. 3, which is a schematic cross-sectional view showing an example of the forward tapered structure of the solder resist layer of this embodiment. Fig. 3 is an enlarged view of Fig. 2. 2, the outer surface 22 of the solder resist layer 20 and the inner surface 23 of the opening 25 have a forward tapered structure that widens from the solder resist layer 20 toward the heat dissipation substrate 30. Here, the outer surface 22 and the inner surface 23 are collectively referred to as the side surface 21. As shown in Figure 3, the angle θ formed by the boundary line L between the plating layer 40 and the solder resist layer 20, the end point B of the boundary line L, and a straight line M connecting a point C on the outline of the side surface 21 of the solder resist layer 20 extending from the end point B, which is at a height H / 2 that is half the thickness H of the solder resist layer 20, is the taper angle in this embodiment.

[0019] According to the inventors' investigations, it was found that there is a correlation between the taper angle of the forward tapered structure of the outer surface of the solder resist layer or the inner surface of the opening in the heat dissipation component, which widens from the solder resist layer towards the heat dissipation substrate when viewed in cross section in the thickness direction, and the adhesion between the plating layer and the solder resist layer. Based on the above findings, the inventors further conducted research and found that, in a cross-sectional view in the thickness direction, the taper angle obtained by measuring the angle θ formed by a boundary line L between the plating layer and the solder resist layer, an end point B of the boundary line L, and a straight line M connecting a point C on the outline of the side surface of the solder resist layer extending from the end point B at a height H / 2 that is half the thickness H of the solder resist layer, was used as an index, and that the taper angle was set to be within the range of 3.00° to 6.00°, both inclusive. This finding led to the completion of the present invention.

[0020] In order to further improve the adhesion between the plating layer and the solder resist layer, the taper angle of the forward tapered structure of the heat dissipation component of this embodiment is 3.00° or more and 6.00° or less, preferably 4.00° or more and 5.98° or less, more preferably 5.00° or more and 5.96° or less, even more preferably 5.50° or more and 5.94° or less, even more preferably 5.70° or more and 5.92° or less, even more preferably 5.80° or more and 5.90° or less, and even more preferably 5.85° or more and 5.88° or less.

[0021] In this embodiment, the taper angle of the forward tapered structure of the heat dissipation member can be measured by, for example, the following method. First, a precision cutting machine is used to cut the heat dissipation member on a plane perpendicular to the heat dissipation substrate. Next, a semi-automatic polishing machine is used to polish the cut surface of the heat dissipation member. Next, an image of the cut surface of the heat dissipation member is taken using a scanning electron microscope. Next, based on the image of the cut surface obtained, the angle θ formed by the boundary line L between the plating layer and the solder resist layer, and the line M connecting the end point B of the boundary line L and point C on the outline of the side of the solder resist layer extending from the end point B at a height H / 2, which is half the thickness H of the solder resist layer, is measured and defined as the taper angle.

[0022] The heat dissipation member of this embodiment can be obtained by appropriately selecting the type of raw material, manufacturing procedure, manufacturing conditions, etc. Regarding the type of raw material, preferably, both electroless Ni-P plating and electroless Ni-B plating are used. Regarding the manufacturing procedure and manufacturing conditions, preferably, a solder resist layer is formed on the heat dissipation member, followed by atmospheric heating treatment, and impregnation, plating, solder resist layer formation, and atmospheric heating treatment are performed under appropriate conditions. These details will be described later.

[0023] The heat dissipation member of this embodiment will now be described in detail.

[0024] <Heat dissipation substrate> The heat dissipation substrate of this embodiment preferably contains a metal-silicon carbide composite, from the viewpoint of further improving the balance of performance among thermal conductivity, reliability, strength, and light weight.

[0025] From the viewpoint of further improving the performance balance of thermal conductivity, reliability, strength, and light weight, the metal-silicon carbide composite of the present embodiment preferably contains one or more elements selected from the group consisting of aluminum, aluminum alloys, magnesium, and magnesium alloys in the silicon carbide porous body, and more preferably contains aluminum in the silicon carbide porous body. Furthermore, the alloy may be, for example, an aluminum alloy containing 7 to 25 mass% silicon (Si). By using an aluminum alloy containing 7 to 25 mass% silicon, it is possible to obtain the effect of promoting densification of the metal-silicon carbide composite.

[0026] When the metal-silicon carbide composite of the present embodiment is an aluminum-silicon carbide composite, the metal contained in the aluminum-silicon carbide composite may contain, in addition to aluminum, which is the main component, one or more elements selected from the group consisting of magnesium, silicon, iron, and copper, as long as the effects of the present invention are not impaired. When the metal-silicon carbide composite of this embodiment is an aluminum-silicon carbide composite, the aluminum content is preferably 60.0 mass % or more and 100.0 mass % or less, more preferably 65.0 mass % or more and 99.9 mass % or less, and even more preferably 70.0 mass % or more and 99.8 mass % or less, when the total amount of metal is taken as 100.0 mass %, from the viewpoint of further improving the performance balance of thermal conductivity, reliability, strength, and light weight.

[0027] From the viewpoint of further improving the balance of thermal conductivity, reliability, strength, and light weight, the heat dissipation substrate of this embodiment preferably further has a surface metal layer between the heat dissipation substrate and the plating layer at least on the first surface side. From the viewpoint of further improving the balance of thermal conductivity, reliability, strength, and light weight, the surface metal layer of this embodiment is more preferably present continuously on the first surface and side surfaces of the heat dissipation substrate, and even more preferably present continuously over the entire surface of the heat dissipation substrate.

[0028] From the viewpoint of further improving the balance of performance among electrical conductivity, reliability, strength, and light weight, the surface metal layer of this embodiment preferably contains one or more selected from the group consisting of aluminum, aluminum alloys, magnesium, and magnesium alloys, and more preferably contains aluminum. Note that, from the viewpoint of further improving the balance of performance among electrical conductivity, reliability, strength, and light weight, it is preferable that the metal contained in the metal-silicon carbide composite and the metal contained in the surface metal layer are the same.

[0029] From the viewpoint of further improving the performance balance of thermal conductivity, reliability, strength, and light weight, the thickness of the heat dissipation substrate of this embodiment is preferably 0.5 mm or more and 10.0 mm or less, more preferably 1.0 mm or more and 8.0 mm or less, even more preferably 2.0 mm or more and 6.0 mm or less, and even more preferably 3.0 mm or more and 5.0 mm or less. In addition, when the thickness of the heat dissipation substrate of this embodiment is not uniform, it is preferable that at least the thickness at the center of gravity of the heat dissipation substrate is within the above range.

[0030] The heat dissipation substrate of this embodiment is preferably substantially rectangular, that is, when viewed from a direction perpendicular to the first surface of the heat dissipation substrate, the shape of the heat dissipation substrate is substantially rectangular. Here, "substantially rectangular" means that at least one of the four corners of the heat dissipation substrate may be processed to have a rounded shape rather than a right-angled shape (of course, the four corners may also be right-angled). If at least one of the four corners of the heat dissipation substrate is rounded, the point where the straight lines of the short and long sides intersect when viewed from above can be defined as the "vertex" of the rectangle. In this case, the "length of the short side" and "length of the long side" of the heat dissipation substrate can be defined with the "vertex" as the start point or end point.

[0031] The length and width of the heat dissipation substrate of this embodiment are not particularly limited, but are, for example, 10 mm×10 mm to 200 mm×150 mm.

[0032] The heat dissipation substrate of this embodiment may have through holes in a direction perpendicular to the first surface. The number, shape, and size of the through holes of this embodiment are not particularly limited. The use of the through holes of this embodiment is not particularly limited, but for example, they are used as screw holes for inserting screws for joining other heat dissipation components. Therefore, from the viewpoint of further improving the joining between the heat dissipation member and other heat dissipation components, it is preferable that a plurality of through holes of this embodiment be present along the outer periphery of the heat dissipation substrate.

[0033] <Plating layer> The heat dissipation component of this embodiment includes a plating layer on at least a first surface of a heat dissipation substrate. Furthermore, from the viewpoint of further improving the performance balance between reliability and bonding with other heat dissipation components, the plating layer of this embodiment is preferably present continuously on the first surface and side surfaces of the heat dissipation substrate, and more preferably present continuously over the entire surface of the heat dissipation substrate.

[0034] From the viewpoint of further improving the performance balance of reliability, bondability with other heat dissipation components, and adhesion between the plating layer and the solder resist layer, the plating layer of this embodiment preferably contains one or more elements selected from the group consisting of Ni, Au, and Ag, more preferably contains a Ni plating layer, and even more preferably contains both a Ni-P plating layer and a Ni-B plating layer.

[0035] From the viewpoint of further improving reliability, the thickness of the plating layer in this embodiment is preferably 1 μm or more and 20 μm or less, more preferably 2 μm or more and 15 μm or less, even more preferably 3 μm or more and 12 μm or less, and even more preferably 4 μm or more and 10 μm or less.

[0036] In this embodiment, the arithmetic mean roughness Ra of the surface of the plating layer, measured in accordance with JIS B0601:2001 (corresponding international standard: ISO4287), is preferably 0.300 μm or more and 3.000 μm or less, more preferably 0.500 μm or more and 2.000 μm or less, even more preferably 0.700 μm or more and 1.500 μm or less, even more preferably 0.800 μm or more and 1.200 μm or less, even more preferably 0.850 μm or more and 1.000 μm or less, and even more preferably 0.900 μm or more and 0.950 μm or less, from the viewpoint of further improving the performance balance of heat dissipation, bondability with other heat dissipation components, and adhesion between the plating layer and the solder resist layer.

[0037] In this embodiment, the average length Rsm of the roughness curve element on the surface of the plating layer, measured in accordance with JIS B0601:2001 (corresponding international standard: ISO4287), is preferably 20.0 μm or more and 250.0 μm or less, more preferably 40.0 μm or more and 200.0 μm or less, even more preferably 50.0 μm or more and 150.0 μm or less, even more preferably 60.0 μm or more and 120.0 μm or less, even more preferably 70.0 μm or more and 100.0 μm or less, and even more preferably 75.0 μm or more and 90.0 μm or less, from the viewpoint of further improving the performance balance of heat dissipation, bondability with other heat dissipation components, and adhesion between the plating layer and the solder resist layer.

[0038] In this embodiment, the arithmetic mean roughness Ra and the mean length Rsm of the roughness curve elements on the surface of the plating layer of the heat dissipation member can be measured by, for example, the following method. First, the arithmetic mean roughness Ra and the mean length Rsm of the roughness curve elements are measured at any five points on the surface of the plating layer of the heat dissipation component using a surface roughness meter in accordance with JIS B0601:2001 (corresponding international standard: ISO4287). Next, the average values ​​of Ra and Rsm are calculated from the measured values ​​of Ra and Rsm at each of the five points, and this is used as the representative value.

[0039] <Solder resist layer> The heat dissipation member of this embodiment includes a solder resist layer having openings on the plating layer. From the viewpoint of further improving electrical insulation, the heat dissipation member of this embodiment preferably includes a solder resist layer on the plating layer on the first surface.

[0040] In order to further improve electrical insulation, the solder resist layer of this embodiment is preferably present over the entire surface of the plating layer on the first surface, excluding the openings. However, for example, if the above-mentioned through holes are present along the periphery of the plating layer on the first surface, the plating layer around the through holes does not need to be covered with the solder resist layer.

[0041] The number and size of the openings in the solder resist layer of this embodiment are not particularly limited as long as they fit within the solder resist layer. The shape of the openings in the solder resist layer of this embodiment is also not particularly limited, and may be, for example, approximately rectangular, approximately circular, or linear. Furthermore, within the opening of the solder resist layer of this embodiment, for example, a through hole may exist, and a solder layer, which will be described later, may be present in contact with the plating layer.

[0042] The thickness of the solder resist layer in this embodiment is preferably 5.0 μm or more and 50.0 μm or less, more preferably 10.0 μm or more and 40.0 μm or less, even more preferably 15.0 μm or more and 30.0 μm or less, and even more preferably 20.0 μm or more and 25.0 μm or less, from the viewpoint of further improving the performance balance of electrical insulation, heat dissipation, and adhesion between the plating layer and the solder resist layer.

[0043] In this embodiment, at least one of the outer surface of the solder resist layer and the inner surface of the opening has a forward tapered structure that widens from the solder resist layer toward the heat dissipation substrate when viewed in cross section in the thickness direction. From the viewpoint of further improving adhesion between the plating layer and the solder resist layer, the solder resist layer of this embodiment preferably has both the outer surface and the inner surface of the opening having a forward tapered structure that widens from the solder resist layer toward the heat dissipation substrate when viewed in cross section in the thickness direction.

[0044] The solder resist layer of the present embodiment preferably contains a cured product of an ultraviolet-curable resin composition, from the viewpoint of further improving the balance of performance among photocurability, electrical insulation, heat resistance, hardness, and adhesion between the plating layer and the solder resist layer.

[0045] The ultraviolet-curable resin composition of the present embodiment preferably contains one or more (meth)acrylic acid ester monomers selected from the group consisting of polyester (meth)acrylate, polyether (meth)acrylate, urethane (meth)acrylate, carbonate (meth)acrylate, and epoxy (meth)acrylate, from the viewpoint of further improving the balance of performance among photocurability, electrical insulation, heat resistance, hardness, and adhesion between the plating layer and the solder resist layer. Examples of the (meth)acrylic acid ester monomer of this embodiment include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; acrylamides such as N,N-dimethylacrylamide, N-methylolacrylamide, and N,N-dimethylaminopropylacrylamide; aminoalkyl acrylates such as N,N-dimethylaminoethyl acrylate and N,N-dimethylaminopropyl acrylate; polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tris-hydroxyethyl isocyanurate, or ethylene oxide adducts thereof; Examples of suitable acrylates include polyhydric acrylates such as pyrene oxide adducts or ε-caprolactone adducts; polyhydric acrylates such as phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adducts or propylene oxide adducts of these phenols; polyhydric acrylates of glycidyl ethers such as glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; acrylates and melamine acrylates obtained by directly acridating polyols such as polyether polyols, polycarbonate diols, hydroxyl-terminated polybutadienes, and polyester polyols, or by urethane acrylate via diisocyanates, as well as methacrylates corresponding to the above acrylates.

[0046] The ultraviolet-curable resin composition of this embodiment was measured using an E-type viscometer at a temperature of 25°C and a shear rate of 19.2 s -1From the viewpoint of further improving the adhesion between the plating layer and the solder resist layer, the viscosity measured under the above conditions is preferably 1 Pa·s or more and 150 Pa·s or less, more preferably 5 Pa·s or more and 100 Pa·s or less, even more preferably 8 Pa·s or more and 70 Pa·s or less, even more preferably 10 Pa·s or more and 50 Pa·s or less, even more preferably 12 Pa·s or more and 30 Pa·s or less, and even more preferably 14 Pa·s or more and 20 Pa·s or less.

[0047] <Physical properties> From the viewpoint of further improving reliability, the average thermal expansion coefficient of the heat dissipation member of this embodiment at 25°C to 150°C is preferably 1.0 ppm / K or more and 20.0 ppm / K or less, more preferably 3.0 ppm / K or more and 15.0 ppm / K or less, even more preferably 5.0 ppm / K or more and 12.0 ppm / K or less, even more preferably 6.0 ppm / K or more and 10.0 ppm / K or less, and even more preferably 7.0 ppm / K or more and 8.0 ppm / K or less.

[0048] In this embodiment, a method for measuring the average thermal expansion coefficient of a heat dissipation component from 25°C to 150°C includes, for example, measuring the dimensional change of the heat dissipation component using a thermomechanical analyzer in accordance with JIS R1618:2002 at a temperature rise rate of 5°C / min or less, and calculating the value when the temperature rises from 25°C to 150°C.

[0049] From the viewpoint of further improving heat dissipation, the thermal conductivity of the heat dissipation member of this embodiment in the thickness direction at 25°C is preferably 50 W / (m·K) or more, more preferably 100 W / (m·K) or more, even more preferably 130 W / (m·K) or more, even more preferably 150 W / (m·K) or more, even more preferably 170 W / (m·K) or more, and even more preferably 190 W / (m·K) or more. The upper limit of the thermal conductivity of the heat dissipation member of this embodiment in the thickness direction at 25°C is not particularly limited, but may be, for example, 500 W / (m·K) or less, 400 W / (m·K) or less, 350 W / (m·K) or less, 300 W / (m·K) or less, 250 W / (m·K) or less, or 220 W / (m·K) or less.

[0050] From the viewpoint of further improving heat dissipation, the thermal conductivity of the heat dissipation member of this embodiment in the thickness direction at 25°C is preferably 50 W / (m·K) or more and 500 W / (m·K) or less, more preferably 100 W / (m·K) or more and 400 W / (m·K) or less, even more preferably 130 W / (m·K) or more and 350 W / (m·K) or less, even more preferably 150 W / (m·K) or more and 300 W / (m·K) or less, even more preferably 170 W / (m·K) or more and 250 W / (m·K) or less, and even more preferably 190 W / (m·K) or more and 220 W / (m·K) or less.

[0051] In this embodiment, the thermal conductivity of the heat dissipation member in the thickness direction at 25°C can be measured, for example, by a laser flash method using a laser flash method thermal property measuring device in accordance with JIS R1611:2010.

[0052] <Application> The heat dissipation member of this embodiment can be used as a heat dissipation component for a power module of an electronic component including a power semiconductor element, etc. An example of the electronic component is an electric conversion device such as an inverter device.

[0053] <Electronic equipment> The electronic device of this embodiment comprises the heat dissipation member of this embodiment, a solder layer inside the opening of the heat dissipation member, an insulating substrate on the solder layer, and an electronic component on the insulating substrate, and the plating layer in the heat dissipation member and the insulating substrate are solder-connected by the solder layer. Here, the electronic device of this embodiment will be described with reference to FIG. 4, which is a schematic cross-sectional view showing an example of the structure of the electronic device of this embodiment.

[0054] As shown in Figure 4, the electronic device 100 comprises a heat dissipation member 10, a solder layer 50 inside the opening 25 of the heat dissipation member 10, an insulating substrate 60 on the solder layer 50, and an electronic component 70 on the insulating substrate 60, and the plating layer 40 in the heat dissipation member 10 and the insulating substrate 60 are solder-connected by the solder layer 50. By joining the electronic component 70 to the plating layer 40 on the surface of the opening 25 of the heat dissipation member 10 via the insulating substrate 60, the heat generated from the electronic component 70 can be efficiently dissipated by the heat dissipation member 10. Furthermore, by joining other heat dissipation components such as heat dissipation fins or a heat dissipation unit to the second surface of the heat dissipation member 10, the heat generated from the electronic component 70 can be dissipated even more efficiently. Furthermore, the surfaces of the heat dissipation member 10 other than the openings 25 on the first surface are covered with the solder resist layer 20, thereby improving the electrical insulation between the electronic component 70 and the plating layer 40.

[0055] <Method of manufacturing heat dissipation member> The heat dissipation member of this embodiment can be obtained by appropriately selecting the type of raw material, the manufacturing procedure, the manufacturing conditions, etc. Specifically, the heat dissipation member of this embodiment is preferably A preparation step of forming a flat porous silicon carbide body (SiC preform); an impregnation step of impregnating a silicon carbide porous body with a metal (alloy) to obtain a heat dissipation substrate including a metal-silicon carbide composite; a plating step of forming a plating layer on at least the first surface of the heat dissipation substrate; a solder resist layer forming step of forming a solder resist layer on the plating layer to obtain a heat dissipation member; an atmospheric heat treatment step of subjecting the heat dissipation member to atmospheric heat treatment; The heat dissipation member can be manufactured through the steps described above. In addition, the heat dissipation member may be manufactured through additional steps other than those described above.

[0056] <Preparation process> In the preparation step of this embodiment, a flat plate-shaped porous silicon carbide body (SiC preform) is formed. As a method for forming a flat silicon carbide porous body (SiC preform), it is preferable to use a manufacturing method in which silica, alumina, or the like is added as a binder to silicon carbide (SiC) powder as a raw material, and the mixture is mixed, molded, and fired, from the viewpoint of further improving the performance balance of heat dissipation, reliability, and strength.

[0057] Here, just as silica, alumina, etc. may be used as raw materials, the silicon carbide porous body does not have to be composed solely of silicon carbide as a chemical component. From the viewpoint of further improving the performance balance of heat dissipation, reliability, and strength, the content of silicon carbide in the silicon carbide porous body of this embodiment is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 95% by mass or less, when the total amount of the silicon carbide porous body is taken as 100% by mass. A higher silicon carbide content in the silicon carbide porous body is preferable because it results in higher thermal conductivity and a lower thermal expansion coefficient, but if the silicon carbide content is too high, the metal may not be sufficiently impregnated in the impregnation step described below.

[0058] It is preferable to adjust the particle size of the SiC powder, which is the raw material for the silicon carbide porous body (SiC preform), by using a suitable combination of coarse powder and fine powder, etc. This makes it easier to achieve both high strength for the silicon carbide porous body (SiC preform) and high thermal conductivity for the final heat dissipation member. Specifically, a mixed powder containing (i) coarse SiC powder with an average particle size of 80 μm to 120 μm and (ii) fine SiC powder with an average particle size of 5 μm to 15 μm is suitable. Here, the ratio of (i) to (ii) in the mixed powder is preferably 50% to 70% by mass for (i) and 20% to 40% by mass for (ii). Furthermore, the relative density of the silicon carbide porous body (SiC preform) of this embodiment is preferably 55% by volume or more and 75% by volume or less, more preferably 60% by volume or more and 70% by volume or less, from the viewpoint of further improving the performance balance of heat dissipation, reliability, and strength.

[0059] In this embodiment, the average particle diameter may be measured by, for example, using a scanning electron microscope and an image analyzer to calculate the average diameter of 1,000 particles. In addition, in this embodiment, the relative density may be measured by, for example, the Archimedes method.

[0060] In this embodiment, methods for forming the silicon carbide porous body (SiC preform) include press molding, extrusion molding, slip casting, etc., and a shape-retaining binder can be used in combination as needed. Among these, press molding is preferred as a method for forming the silicon carbide porous body (SiC preform).

[0061] A porous silicon carbide body (SiC preform) can be obtained by degreasing and firing a compact of a mixture of SiC powder and a binder. In this embodiment, the firing temperature of the molded body is preferably 800° C. or higher and 1000° C. or lower, more preferably 850° C. or higher and 950° C. or lower, from the viewpoint of further improving the performance balance of heat dissipation, reliability, and strength. By setting the firing temperature at or above the lower limit, a silicon carbide porous body (SiC preform) with high bending strength can be easily obtained regardless of the firing atmosphere. Furthermore, by setting the firing temperature at or below the upper limit, oxidation of SiC can be promoted, thereby preventing a decrease in the thermal conductivity of the metal-silicon carbide composite. The firing time can be determined appropriately depending on conditions such as the size of the silicon carbide porous body (SiC preform), the amount put into the firing furnace, and the firing atmosphere, but is preferably from 1 hour to 3 hours.

[0062] When forming porous silicon carbide (SiC preforms) into a predetermined shape, changes in shape due to drying (for example, changes in the amount of curvature) can be suppressed by drying each preform individually or by using spacers such as carbon with the same shape as the preforms between the SiC preforms. Furthermore, by carrying out the same treatment for firing as for drying, it is possible to prevent changes in shape due to changes in the internal structure.

[0063] <Impregnation process> In the impregnation step of this embodiment, a metal (alloy) is impregnated into a silicon carbide porous body to obtain a heat dissipation substrate including a metal-silicon carbide composite. As a method for impregnating a silicon carbide porous body with a metal (alloy) to obtain a heat dissipation substrate containing a metal-silicon carbide composite, the following method is preferably used, from the viewpoint of further improving the performance balance of heat dissipation, reliability, strength, and light weight.

[0064] First, a silicon carbide porous body (SiC preform) is set in a mold, and then molten metal is poured into the mold. The molten metal is then pressed, impregnating the voids in the silicon carbide porous body (SiC preform). After cooling, a heat dissipation substrate containing a metal-silicon carbide composite is obtained. From the viewpoint of further improving the performance balance of heat dissipation, reliability, strength, and light weight, the molten metal of the present embodiment preferably contains one or more materials selected from the group consisting of aluminum, aluminum alloys, magnesium, and magnesium alloys, and more preferably contains aluminum.

[0065] Here, when setting the silicon carbide porous body (SiC preform) in the mold, it is preferable to preheat it from the viewpoint of further improving the performance balance of heat dissipation, reliability, and strength. The preheating temperature is preferably 550°C or higher and 650°C or lower. In order to prevent a drop in temperature, it is preferable to pour molten metal into the silicon carbide porous body (SiC preform) as quickly as possible after setting it in the mold.

[0066] When a heat dissipation substrate containing a metal-silicon carbide composite is obtained by impregnating a silicon carbide porous body (SiC preform) with metal, it is preferable to provide a surface metal layer on at least the first surface of the heat dissipation substrate. From the viewpoint of further improving the performance balance of heat dissipation, reliability, and strength, a method of providing a surface metal layer on at least the first surface of the heat dissipation substrate is to prepare a mold slightly larger than the SiC preform as a mold for impregnation, place the SiC preform in the mold, and pour molten metal into the mold. Furthermore, when using the above method, from the viewpoint of further improving the performance balance of heat dissipation, reliability, and strength, it is more preferable to provide a surface metal layer continuously on the first surface and side surfaces of the heat dissipation substrate, and it is even more preferable to provide a surface metal layer continuously over the entire surface of the heat dissipation substrate.

[0067] The pressing pressure in the impregnation step of this embodiment is preferably 80 MPa or more and 120 MPa or less, more preferably 90 MPa or more and 110 MPa or less, from the viewpoint of sufficiently impregnating the metal and further improving the performance balance of heat dissipation, reliability, and strength. The pressing time in the impregnation step of this embodiment is preferably 10 minutes or more and 30 minutes or less, more preferably 15 minutes or more and 25 minutes or less, from the viewpoint of sufficiently impregnating the metal and further improving the performance balance of heat dissipation, reliability, and strength.

[0068] The melting point of the molten metal in this embodiment is preferably moderately low from the viewpoint of sufficiently impregnating the metal and further improving the performance balance of heat dissipation, reliability, and strength. In this regard, the silicon content of the molten metal in this embodiment is preferably 10% by mass or more and 15% by mass or less, and more preferably 11% by mass or more and 13% by mass or less, when the total amount of the molten metal is taken as 100% by mass. Furthermore, from the viewpoint of further strengthening the bond between the silicon carbide grains and the metal portion, the magnesium content of the molten metal in this embodiment is preferably 0.5% by mass or more and 1.5% by mass or less, and more preferably 0.8% by mass or more and 1.2% by mass or less, when the total amount of the molten metal is taken as 100% by mass. There are no particular restrictions on the metal components other than aluminum, silicon, and magnesium in the molten metal as long as they do not significantly change the properties, and for example, copper may be included.

[0069] The temperature of the molten metal in this embodiment is preferably 700°C or higher and 900°C or lower, more preferably 750°C or higher and 850°C or lower, from the viewpoint of sufficiently impregnating the metal and further improving the performance balance of heat dissipation, reliability, and strength.

[0070] The impregnation step of this embodiment can be performed by stacking multiple silicon carbide porous bodies alternately with stainless steel plates, simultaneously impregnating the stacked silicon carbide porous bodies with a metal (alloy) to form a metal block containing a metal-silicon carbide composite, and then cutting the metal block to obtain multiple heat dissipation substrates. By using this method, the productivity of heat dissipation members can be further improved.

[0071] After the impregnation step of this embodiment, the outer periphery of the obtained heat dissipation substrate may be machined using a lathe to adjust the dimensions of the heat dissipation substrate.

[0072] To remove strain caused during the impregnation process, the metal-silicon carbide composite may be annealed at a temperature of 400°C to 550°C for 10 minutes or longer.

[0073] <Plating process> In the plating step of this embodiment, a plating layer is formed on at least the first surface of the heat dissipation substrate. From the viewpoint of further improving the balance of reliability and bonding with other heat dissipation components, the plating layer of this embodiment is preferably formed continuously on the first surface and the side surfaces of the heat dissipation substrate, and more preferably formed continuously over the entire surface of the heat dissipation substrate.

[0074] The plating process of this embodiment can use known techniques such as electroless Ni-P plating and electroless Ni-B plating. However, from the viewpoint of further improving the performance balance of reliability, bondability with other heat dissipation components, and adhesion between the plating layer and the solder resist layer, it is preferable to use both electroless Ni-P plating and electroless Ni-B plating.

[0075] After the plating step of this embodiment, the surface of the resulting plating layer may be polished or blasted. This allows, for example, the surface roughness Ra or the average length Rsm of the roughness curve element of the plating layer surface to be appropriately adjusted, thereby further improving the adhesion between the plating layer and the solder resist layer. The specific method for the polishing or blasting can be appropriately applied using known techniques.

[0076] <Solder resist layer formation process> In the solder resist layer forming step of this embodiment, a solder resist layer is formed on a plating layer to obtain a heat dissipation member. As a method for forming a solder resist layer on a plating layer and obtaining a heat dissipation component, it is preferable to use a method in which the solder resist is applied to the plating layer and cured by exposing it to ultraviolet light, from the viewpoint of further improving adhesion between the plating layer and the solder resist layer.

[0077] In this embodiment, examples of methods for applying the solder resist onto the plating layer include spin coating using a spinner, spray coating, roll coating, screen printing, or coating methods using a blade coater, die coater, calendar coater, meniscus coater, bar coater, roll coater, comma roll coater, gravure coater, screen coater, slit die coater, etc., but screen printing is preferably used from the viewpoint of further improving adhesion between the plating layer and the solder resist layer. In this embodiment, when the solder resist is applied onto the plating layer using screen printing, the solder resist can be applied so as to form a resist pattern having a predetermined shape on the plating layer.

[0078] The coating thickness of the solder resist of this embodiment is preferably 5 μm or more and 45 μm or less, more preferably 10 μm or more and 35 μm or less, and even more preferably 15 μm or more and 30 μm or less, from the viewpoint of further improving adhesion between the plating layer and the solder resist layer.

[0079] In this embodiment, the solder resist applied on the plating layer is exposed to ultraviolet light to harden the solder resist. The exposure dose of ultraviolet light is preferably 1000 mJ / cm 2 in order to sufficiently harden the solder resist. 2 More preferably, 1200 mJ / cm 2 That's all.

[0080] <Atmospheric heat treatment process> In the atmospheric heat treatment step of this embodiment, the heat dissipation member obtained through the above steps is subjected to atmospheric heat treatment. The inventors have found that the taper angle of the forward tapered structure of the solder resist layer can be controlled by performing atmospheric heat treatment after exposing the solder resist to ultraviolet light and adjusting the treatment conditions appropriately. Therefore, performing atmospheric heat treatment on the heat dissipation component under appropriate conditions and setting the taper angle within the range of 3.00° to 6.00° is important for improving the adhesion between the plating layer and the solder resist layer.

[0081] From the viewpoint of further improving the adhesion between the plating layer and the solder resist layer, the atmospheric heat treatment step of this embodiment preferably employs a method in which the heat dissipation component is placed flat on a shelf and carried into a hot air circulating furnace, heated to a predetermined treatment temperature at a predetermined heating rate in the atmosphere, maintained at the treatment temperature for a predetermined treatment time, and then allowed to cool naturally in the furnace before being removed.

[0082] The treatment temperature of the atmospheric heat treatment step in this embodiment is preferably 160°C or higher and 220°C or lower, more preferably 170°C or higher and 220°C or lower, even more preferably 180°C or higher and 210°C or lower, and even more preferably 190°C or higher and 210°C or lower, from the viewpoint of further improving the adhesion between the plating layer and the solder resist layer.

[0083] The treatment time for the atmospheric heat treatment step in this embodiment is preferably 20 minutes or more and 40 minutes or less, more preferably 25 minutes or more and 35 minutes or less, from the viewpoint of further improving the adhesion between the plating layer and the solder resist layer.

[0084] The temperature rise rate in the atmospheric heat treatment step of this embodiment is preferably 3°C / min or more and 7°C / min or less, more preferably 4°C / min or more and 6°C / min or less, from the viewpoint of further improving the adhesion between the plating layer and the solder resist layer.

[0085] The method for manufacturing the heat dissipation member of this embodiment may include other steps not described above. For example, a step of forming through holes for screwing may be included. Specifically, through holes for screwing can be formed by machining or the like to join with other components. The positions of the through holes for screwing and the like have already been described, so a detailed description is omitted here. The step of providing through holes for screw fastening may be carried out during or after any of the steps.

[0086] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0087] The present invention will be described in detail based on examples and comparative examples, but the present invention is not limited to these examples.

[0088] [Example 1] <Preparation process> 300 g of silicon carbide powder A (NG-150 manufactured by Pacific Random Corporation, average particle size: 100 μm), 150 g of silicon carbide powder B (GC-1000F manufactured by Yakushima Denko Co., Ltd., average particle size: 10 μm), and 30 g of silica sol (Snowtex manufactured by Nissan Chemical Industries, Ltd.) were mixed in a stirrer mixer for 30 minutes. The resulting mixture was placed in a 178 mm × 128 mm × 5.5 mm mold and press-molded at a pressure of 10 MPa. This was then fired in air at 900°C for 2 hours to obtain a silicon carbide porous body. For the following steps, 30 similar porous silicon carbide bodies were prepared.

[0089] <Impregnation process> The silicon carbide porous body was sandwiched between two 210mm x 160mm x 0.8mm stainless steel (SUS304) plates coated with a release agent on both sides, and 30 of these plates were stacked. 6mm thick steel plates were then placed on both ends and secured with 10mm diameter bolts and nuts to form a block.

[0090] The above block was preheated in an electric furnace to a temperature of 600° C. Thereafter, the block was placed in a preheated press mold having a cavity with inner dimensions of 400 mmφ×300 mm. Then, molten aluminum (manufactured by Nikkei MC Aluminum Co., Ltd., 1260412 1.2 mg brown) containing 12% silicon, 1% magnesium, and the remainder consisting of aluminum and unavoidable impurities, at a temperature of 800°C, was poured into the press mold and pressurized at a pressure of 100 MPa for 20 minutes, thereby impregnating the silicon carbide porous body with aluminum and obtaining a metal ingot containing an aluminum-silicon carbide composite. The resulting metal block was cooled to room temperature, then cut using a wet band saw along the side profile of the release plate, and the sandwiched stainless steel plate was removed to obtain a heat dissipation substrate containing an aluminum-silicon carbide composite and covered with a surface metal layer containing aluminum. The outer periphery of the resulting heat dissipation substrate was then machined using an NC lathe to a size of 180 mm x 130 mm.

[0091] <Plating process> The resulting heat dissipation substrate was cleaned by blasting with alumina abrasive grains at a pressure of 0.4 MPa and a transfer speed of 1.0 m / min. Electroless Ni-P and Ni-B plating were then performed. This resulted in a continuous plating layer of 8 μm thick (Ni-P: 6 μm, Ni-B: 2 μm) formed over the entire surface of the heat dissipation substrate.

[0092] <Solder resist layer formation process> A solder resist (ultraviolet-curable resin composition, viscosity: 15 Pa·s, manufactured by Taiyo Ink Co., Ltd., UVR-150G R60) was applied by screen printing to the entire first surface of the heat dissipation substrate covered with the plating layer so that the solder resist layer had a thickness of 22 μm, thereby obtaining a solder resist film. The obtained solder resist film was exposed to 1200 mJ / cm 2 using an exposure device (UVK-75M3JG, manufactured by Ceria Corporation) so that the entire area was exposed. 2 The heat dissipation member was obtained by exposure to light.

[0093] <Atmospheric heat treatment process> The obtained heat dissipation member was placed flat on a shelf and carried into a small box furnace (KBF828N, manufactured by JTEKT Thermo Systems Corp.). Next, the temperature was increased from 25°C to 200°C at a rate of 5°C / min in the atmosphere, and the temperature was maintained at 200°C for 30 minutes, thereby performing an atmospheric heat treatment. Next, the heat dissipation member was allowed to cool naturally in the furnace and then removed. In this way, the heat dissipation member of Example 1 was obtained.

[0094] [Example 2] A heat dissipation member of Example 2 was obtained in the same manner as in Example 1, except that the treatment temperature in the atmospheric heat treatment step was set to 170°C.

[0095] [Comparative Example 1] A heat dissipation member of Comparative Example 1 was obtained in the same manner as in Example 1, except that the atmospheric heat treatment temperature was 140°C and the plating was an 8 μm thick plating layer of Ni—P alone.

[0096] Comparative Example 2 A heat dissipation member of Comparative Example 2 was obtained in the same manner as in Example 1, except that the atmospheric heat treatment step was not carried out.

[0097] <Taper angle, thickness> First, the heat dissipation component was cut perpendicular to the heat dissipation substrate using a precision cutting machine (T210, manufactured by Sankei Corporation). Next, the cut surface of the heat dissipation component was polished using a semi-automatic polishing machine (Automet 250, manufactured by Buehler). Images of the cut surface of the heat dissipation component were then taken using a scanning electron microscope (SU6600, manufactured by Hitachi High-Technologies Corporation). Based on the image of the cut surface, the angle θ formed by the boundary line L between the plating layer and the solder resist layer, the line M connecting the end point B of the boundary line L and a point C on the outer edge of the side of the solder resist layer extending from the end point B at a height H / 2 (half the thickness H of the solder resist layer), was measured and defined as the taper angle of the forward tapered structure of the solder resist layer. The thickness of the solder resist layer was also measured based on the image of the cut surface. The results are shown in Table 1.

[0098] <Ra、Rsm> The arithmetic mean roughness Ra and the mean length of the roughness curve element Rsm were measured at five arbitrary points on the surface of the plating layer of the heat dissipation component using a surface roughness meter (Mitutoyo Corporation, SJ-310) in accordance with JIS B0601:2001 (corresponding international standard: ISO4287). Next, the average values ​​of Ra and Rsm were calculated from the measured values ​​of Ra and Rsm at each of the five arbitrary points, and used as the representative value. The results are shown in Table 1.

[0099] <Average thermal expansion coefficient> Using a thermomechanical analyzer (TMA8310, manufactured by Rigaku Corporation) in accordance with JIS R1618:2002, the dimensional changes of the heat dissipation components were measured at a heating rate of 5°C / min or less, and the average thermal expansion coefficient of the heat dissipation components from 25°C to 150°C was calculated using the values ​​obtained when the temperature was raised from 25°C to 150°C. The results are shown in Table 1.

[0100] <Thermal conductivity> The thermal conductivity of the heat dissipation member in the thickness direction at 25° C. was measured by the laser flash method in accordance with JIS R1611:2010 using a laser flash method thermal property measuring device (LFA-502, manufactured by Kyoto Electronics Manufacturing Co., Ltd.). The results are shown in Table 1.

[0101] <Adhesion between plating layer and solder resist layer> Solder paste was applied to the openings in the solder resist layer of the heat dissipation component. A metal plate of the same size as the openings in the solder resist was then placed on the solder paste to obtain a laminate. The resulting laminate was then heated at approximately 300°C for 10 minutes. After the laminate was cooled to room temperature, the adhesion between the plating layer and the solder resist layer was visually inspected, and the adhesion was evaluated according to the following criteria. A: No peeling is observed between the plating layer and the solder resist layer. B: Peeling is observed in a part between the plating layer and the solder resist layer. C: Peeling is observed throughout the entire area between the plating layer and the solder resist layer.

[0102] [Table 1]

[0103] The heat dissipation members of Examples 1 and 2, in which the forward tapered structure of the solder resist layer had a taper angle of 3.00° or more and 6.00° or less, were evaluated as A or B in terms of adhesion between the plating layer and the solder resist layer. On the other hand, the heat dissipation members of Comparative Examples 1 and 2, in which the forward tapered structure of the solder resist layer had a taper angle of more than 6.00°, were evaluated as C for the adhesion between the plating layer and the solder resist layer. From this, it can be seen that the heat dissipation members of Examples 1 and 2 had improved adhesion between the plating layer and the solder resist layer compared to the heat dissipation members of Comparative Examples 1 and 2. [Explanation of symbols]

[0104] 10 Heat dissipation material 20 Solder resist layer 21 Side 22 External surface 23 Inner surface 25 Opening 30 Heat dissipation board 40 plating layer 50 solder layer 60 Insulating substrate 70 Electronic Components 100 Electronic equipment B End point of boundary line L C: The point at height H / 2 on the outline of the side surface extending from end point B H Thickness of solder resist layer H / 2 Half the height of the solder resist layer L Boundary line between plating layer and solder resist layer M A straight line connecting endpoint B and point C θ is the angle between the boundary line L and the line M

Claims

1. A heat dissipation substrate; a plating layer on at least a first surface of the heat dissipation substrate; a solder resist layer having openings on the plating layer, at least one of an outer surface of the solder resist layer and an inner surface of the opening has a forward tapered structure that widens from the solder resist layer toward the heat dissipation substrate when viewed in a cross section in the thickness direction; A heat dissipation member according to the following method 1, wherein the taper angle of the forward tapered structure is 3.00° or more and 6.00° or less. (Method 1) In a cross-sectional view in the thickness direction, the angle θ formed by a boundary line L between the plating layer and the solder resist layer, an end point B of the boundary line L, and a straight line M connecting a point C on the outline of the side surface extending from the end point B at a height H / 2 that is half the thickness H of the solder resist layer, is measured and defined as the taper angle.

2. The heat dissipation member according to claim 1 , wherein the solder resist layer has a thickness of 5.0 μm or more and 50.0 μm or less.

3. The heat dissipation member according to claim 1 , wherein the solder resist layer contains a cured product of an ultraviolet-curable resin composition.

4. The heat dissipation member according to claim 3, wherein the ultraviolet-curable resin composition contains one or more (meth)acrylic acid ester monomers selected from the group consisting of polyester (meth)acrylate, polyether (meth)acrylate, urethane (meth)acrylate, carbonate (meth)acrylate, and epoxy (meth)acrylate.

5. The ultraviolet-curable resin composition was measured using an E-type viscometer at a temperature of 25°C and a shear rate of 19.2 s －１ 4. The heat dissipation member according to claim 3, wherein the viscosity measured under the conditions above is 1 Pa·s or more and 150 Pa·s or less.

6. The heat dissipation member according to claim 1 or 2, wherein the plating layer contains one or more elements selected from the group consisting of Ni, Au, and Ag.

7. The heat dissipation member according to claim 6 , wherein the plating layer includes a Ni plating layer.

8. The heat dissipation member according to claim 1 or 2, wherein the arithmetic mean roughness Ra of the surface of the plating layer, measured in accordance with JIS B0601:2001 (corresponding international standard: ISO 4287), is 0.300 μm or more and 3.000 μm or less.

9. 3. The heat dissipation member according to claim 1, wherein the average length Rsm of the roughness curve elements on the surface of the plating layer, measured in accordance with JIS B0601:2001 (corresponding international standard: ISO 4287), is 20.0 μm or more and 250.0 μm or less.

10. The heat dissipation member according to claim 1 or 2, wherein the plating layer has a thickness of 1 μm or more and 20 μm or less.

11. The heat dissipation member according to claim 1 , wherein the plating layer is present continuously on the first surface and the side surfaces of the heat dissipation substrate.

12. The heat dissipation member according to claim 1 or 2, wherein the heat dissipation substrate comprises a metal-silicon carbide composite.

13. 13. The heat dissipation member according to claim 12, wherein the metal-silicon carbide composite contains one or more elements selected from the group consisting of aluminum, aluminum alloys, magnesium, and magnesium alloys in a silicon carbide porous body.

14. The heat dissipation member described in claim 13, further comprising a surface metal layer between the heat dissipation substrate and the plating layer, at least on the first surface side, the surface metal layer containing one or more selected from the group consisting of aluminum, aluminum alloy, magnesium, and magnesium alloy.

15. 15. The heat dissipation member according to claim 14, wherein said metal-silicon carbide composite contains aluminum in said porous silicon carbide body, and said surface metal layer contains aluminum.

16. 3. The heat dissipation member according to claim 1, wherein the average coefficient of thermal expansion at 25°C to 150°C is 1.0 ppm / K or more and 20.0 ppm / K or less.

17. The heat dissipation member according to claim 1 or 2, having a thermal conductivity in the thickness direction at 25°C of 50 W / (m·K) or more.

18. The heat dissipation member according to claim 1 or 2; a solder layer inside the opening of the heat dissipation member; an insulating substrate on the solder layer; an electronic component on the insulating substrate, The electronic device is configured such that the plating layer in the heat dissipation member and the insulating substrate are solder-connected by the solder layer.

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