JP5473407B2 - Ceramic substrate, heat dissipation substrate, and electronic device - Google Patents

Description

The present invention relates to a ceramic board to place the heat radiation member. Further, in the ceramic base plate, insulated gate bipolar transistor (IGBT) devices, metal-oxide field effect transistor (MOSFET) device, a light emitting diode (LED) element, a freewheeling diode (FWD) element, giant transistors the semiconductor device (GTR) devices such as a sublimation type thermal printer head element relates to heat dissipation board on which various electronic parts such as a thermal ink jet printer head element is mounted. Further, an electronic device which various electronic components are mounted on the heat radiating base plate.

Recently, heat radiation board of an electronic device such as a semiconductor device is known which is represented by a power module such as a power transistor module or a switching power supply. As the heat radiating base plate, and bonding a copper plate as a circuit member on one principal surface of the ceramic substrate and the heat radiating base plate which is formed by joining a copper plate is used as a good heat dissipation member of the heat radiation property on the other principal surface Yes.

For example, in Patent Document 1, in an aluminum nitride circuit board including an aluminum nitride substrate and a metallized layer formed on the aluminum nitride substrate, a height of 1 nm or more is formed on the surface of the aluminum nitride substrate excluding the formation region of the metallized layer. An aluminum nitride circuit board on which protrusions of 500 nm or less are formed has been proposed.

  In Patent Document 1, as shown in FIG. 12, reference numeral 71 denotes an AlN substrate made of an AlN sintered body, and a metallized layer 72 is formed on the surface 71 a of the AlN substrate 71. As the metallized layer 72, an AlN circuit substrate 70 that functions as a surface wiring layer 73, an element mounting portion 74, or the like is disclosed.

  On the surface 71a of the AlN substrate 71, except for the formation region of the metallized layer 72, minute projections 75 are formed as shown in the enlarged view of FIG. The shape of the protrusion 75 is, for example, a shape based on a conical shape, a cylindrical shape, a hemispherical shape, or the like.

  Further, in Patent Document 2, as shown in FIG. 13, a ceramic in which a metal film is formed by vapor deposition on a ceramic surface in which ultrafine irregularities smaller than the crystal grain size are formed on the crystal grain surface by an ion beam etching process. A circuit board manufacturing method is disclosed.

Japanese Patent Laid-Open No. 9-17909 Japanese Patent Laid-Open No. 5-24959

  However, in the AlN circuit board 70 disclosed in Patent Document 1, in the manufacturing process of the AlN substrate, when the plate-like molded bodies made of AlN are stacked and baked, the auxiliary component is partially detached from the molded body by heating, Adjacent sintered bodies are fixed in the formation region of the metallized layer 72 after firing. For this reason, it is difficult to separate the obtained sintered bodies.

  In addition, since the ceramic circuit board disclosed in Patent Document 2 irradiates the ceramic surface with ion beam etching, the irregularities formed on the ceramic surface are ultrafine than the crystal grain size. For this reason, even if it heats after apply | coating the paste of the metallized composition which added the active metal, sufficient anchor effect is not acquired on the ceramic surface, but a metallized layer is hard to obtain high adhesive force with respect to a ceramic substrate.

The present invention has been proposed in order to solve the above-described problems, and is obtained by stacking and firing plate-like molded bodies, and the obtained sintered bodies are difficult to adhere to each other. ceramic base plate can be firmly adhered layer, there is provided a heat radiating base plate and the electronic device.

The ceramic substrate according to an aspect of the present invention is a ceramic substrate including a plurality of protrusions on at least one main surface, and the protrusion has a maximum value of a difference in height between adjacent peak portions and valley bottom portions. It has a size I凹 convex than the average grain size of crystals constituting the substrate, wherein the average height of the protrusions is 16μm or more 52μm or less.

Further, heat radiation board according to an embodiment of the present invention is characterized in that the heat dissipation member to the ceramic base plate is bonded.

Further, heat radiation board according to an embodiment of the present invention, and the ceramic board, a metal layer projections are formed on the formed surface of the ceramic board, a heat radiation member disposed on the metal layer It is characterized by having.

Further, heat radiation board according to an embodiment of the present invention includes a binding layer mainly composed of the active metal layer and copper are sequentially laminated on both main surfaces of the ceramic board, it is disposed on each binding layer And at least one copper plate mainly composed of copper or a copper alloy, using the copper plate on one main surface as a circuit member and using the copper plate on the other main surface as a heat dissipation member. Features.

Further, an electronic device according to an embodiment of the present invention is characterized by comprising an electronic component on the heat radiation board.

According to the ceramic board according to an embodiment of the present invention, it can be released easily sintered body adjacent after firing. Further, a paste containing a metal is applied to the surface of the sintered body, when heated, provides high anchor effect can be firmly adhered as a metallized layer of the active metal layer such as a ceramic board.

Further, according to the heat radiating base plate and the electronic apparatus according to an embodiment of the present invention, sintered bodies adjacent after sintering is easily detached, because of the use of ceramic board mechanical properties little impaired it can be a high heat dissipation board and an electronic device durable.

Shows the ceramic board according to an embodiment of the present invention, (a) is a plan view when viewed in plan from above, (b) is a cross-sectional view taken along line A-A 'in FIG. (A), (c) is Sectional drawing in the BB 'line | wire of the same figure (a), (d) is the a section enlarged view of the same figure (b). Shows the ceramic board according to an embodiment of the present invention, (a) is a plan view when viewed in plan from above, (b) is a cross-sectional view taken along line C-C 'of FIG. (A), (c) is Sectional drawing in the DD 'line | wire of the same figure (a), (d) is the a section enlarged view of the same figure (b). Shows an embodiment of a ceramic board, (a) is a plan view when viewed in plan from above, (b) is a cross-sectional view taken along line E-E 'of FIG. (A), (c) the drawing ( Sectional drawing in the FF 'line | wire of a), (d) is the b section enlarged view of the same figure (b). Shows an embodiment of a ceramic base plate, (a) is a plan view when viewed in plan from above, (b) is a cross-sectional view taken along line G-G 'in FIG. (A), (c) the drawing ( Sectional drawing in the HH 'line of a), (d) is the b section enlarged view of the same figure (b). Shows the ceramic board according to an embodiment of the present invention, (a) is a plan view when viewed in plan from above, (b) is a cross-sectional view taken along line I-I 'in FIG. (A), (c) is Sectional drawing in the JJ 'line | wire of the figure (a), (d) is the a section enlarged view of the figure (b). Shows the ceramic board according to an embodiment of the present invention, (a) is a plan view when viewed in plan from above, (b) is a cross-sectional view taken along K-K 'line in FIG. (A), (c) is Sectional drawing in the LL 'line | wire of the same figure (a), (d) is the a section enlarged view of the same figure (b). Shows the heat radiation board according to an embodiment of the present invention, (a) is a plan view when viewed in plan from the circuit member side, (b) is a cross-sectional view taken along M-M 'line of FIG. (A), (c FIG. 4B is an enlarged view of part c of FIG. Shows the heat radiation board according to an embodiment of the present invention, (a) is a plan view when viewed in plan from the circuit member side, (b) is a cross-sectional view taken along N-N 'line of FIG. (A), (c ) Is an enlarged view of a portion d in FIG. Shows the heat radiation board according to an embodiment of the present invention, (a) is a plan view when viewed in plan from the circuit member side, (b) is a cross-sectional view taken along O-O 'line in FIG. (A), (c ) Is a bottom view in a plan view from the heat radiating member side. Multiline circuit member in plan view, shows a partitioned arranged radiating board in a plurality of rows, (a) is a plan view when viewed in plan from the circuit member side, (b) heat radiation shown in the diagram (a) shows a warp of the board schematically, (c) one line in a plan view circuit member, shows a heat radiating base plate is divided disposed in a plurality of columns, (d) the radiating groups shown in (c) It is a figure which shows the curvature of a board typically. Shows the heat radiation board according to an embodiment of the present invention, (a) is a plan view when viewed in plan from the circuit member side, (b) is a cross-sectional view taken along P-P 'line of FIG. (A), (c ) Is a bottom view in a plan view from the heat radiating member side. It is sectional drawing which shows the structure of the conventional ceramic circuit board. It is a schematic sectional drawing showing the state after the in-on-beam etching process of the unpolished surface part of the ceramic substrate used for implementation of the manufacturing method of the conventional ceramic circuit board.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a mode for carrying out the present invention (hereinafter referred to as the present embodiment) will be described in detail with reference to the drawings.

Ceramic base plate of the present embodiment comprises a large number of impact force that having a mean concave convex height greater than the grain size of crystals constituting the ceramic substrate. Specifically, for example, as shown in FIG. 1, at least on the first surface 1a of the ceramic base plate 1 is a substrate, a number of projections 1c forming the unevenness repeated in a predetermined plurality of directions (s) is formed Yes. The second surface 1b on the back side of the first surface 1a is planar.

Further, as shown in FIG. 2, the first surface 1a and the second surface 1b is both major surfaces, ceramic base plate surface are a number of protrusions 1c which forms a concavo-convex shape repeating the plurality of directions are formed It may be 1.

Further, in FIG. 3, the first surface 1a is at least one main face, surface shows an example in which a large number are formed dimples 1d are no irregularities repeatedly to multiple directions. In addition, the 2nd surface 1b which is the other main surface is planar.

Further, in FIG. 4, the first surface 1a and the second surface 1b is both major surfaces, the surface shows an example in which a large number are formed dimples 1d are no irregularities repeatedly to multiple directions.

As shown in FIG. 1-2, according to the ceramic base plate 1 of this embodiment, on at least one surface, the surface having an average grain size greater height than the crystals constituting the ceramic substrate 1 to the plurality of directions irregularities since the projection 1c is made large number forms having, it can be released easily sintered body adjacent after firing. Further, a paste containing a metal is applied to the surface, when heated, high anchor effect can be obtained, it can be firmly adhered to the metallized layer of the active metal layer such as a ceramic board 1.

Note that the height of the unevenness, by photographing a cross-section including the surface of the ceramic base plate 1 at 2000 times magnification scanning electron microscopy, in the length 500 [mu] m, the height difference between the crest p and valley portions v adjacent it is the maximum value pv. The size of the irregularities is greater than the average grain size of crystals constituting the ceramic base plate 1, for example, the average crystal grain size of crystals constituting the ceramic base plate 1 is a 0.5μm or 13μm or less Yes, this average crystal grain size can be determined according to JIS R 1670-2006.

Further, as shown in FIG. 1-2, in particular, the main surface 1a, the surface over the entire surface of the 1b it is preferred that the number of repeated concavo-convex shape that not make collision force 1c plurality of directions is formed.

Each external shape of the collision force 1c, for example hemispherical, frustoconical, or if either conical or cylindrical. In particular, as shown in FIG. 1-2, it is preferable that the surface of the impact force 1c is formed in a hemispherical shape. Thus, when the surface of the impact force 1c is formed in a semi-spherical shape, as compared with the shape other than hemispherical, residual stress after firing so hard remain in the sintered body, strength is hardly lowered.

Further, collision force. 1c, be present alone, as shown in FIG. 1-2, not shown, may be present as multiple protrusions 1c overlap, as shown in FIG. 5 it may be a ceramic board 1 projection 1c is arranged at equal intervals in a predetermined direction. In Figure 5, although the longitudinal direction and the width direction the predetermined direction on the first surface 1a of the ceramic base plate 1, the predetermined direction may be one direction. Further, as shown in Figure 6, it may be a ceramic board 1 projection 1c are arranged side by side at equal intervals and staggered.

As in the ceramic base plate 1 shown in FIGS. 5 and 6, when the protrusion 1c are arranged at regular intervals, the protrusions 1c has a regular arrangement. Therefore, Ru can be pulled apart more easily sintered body adjacent after firing.

Figure 1, on the surface of the ceramic base plate 1 shown in 2,4 6, for example, Ti, Zr, Hf, applying a paste containing an active metal such as Nb, interposing the active metal layer obtained by heating Thus, a metal plate such as a copper plate can be joined.

When joining a metal plate in such a way, the height h of the collision force 1c, ease and the peeling of the sintered body adjacent after firing, the voids generated in the ceramic base plate 1 and the active metal interlayer size Is different. That is , when the value of the height h is small, voids hardly remain , and when the value of the height h is large, the sintered bodies are easily separated from each other.

From this point of view, the average height h of the protrusions 1c which definitive in the ceramic base plate 1 of this embodiment, Ru der least 52μm or less 16 [mu] m. Thereby, the adjacent sintered bodies can be easily separated after firing. Furthermore, even by applying a paste containing an active metal on the surface of the sintered body, to escape easily the air present between the projections 1c adjacent, ceramic base plate 1, the gap hardly remains in the active metal layers.

The height h of the impact force. 1c, taken at 2000 × magnification cross-section of the ceramic base plate 1 with a scanning electron microscope may be measured in the length 500 [mu] m.

Figure 1, as shown in 2,4 6, the ceramic base plate 1 of this embodiment, a ceramic having an insulating property, for example, silicon nitride, aluminum oxide, aluminum nitride, zirconium oxide, beryllium oxide and boron nitride 1 Because it is made of ceramics whose main component is more than seeds, it has excellent heat dissipation characteristics. Ceramic board 1, for example, is 30mm or more 80mm or less in length, width is not less 10mm or more 80mm or less, although the thickness varies depending on the application, to suppress the heat resistance, from the viewpoint of maintaining the durability, the thickness 0 It is preferable that the thickness is not less than 13 mm and not more than 0.64 mm.

Further, according to the ceramic base plate 1 of the present embodiment, it is preferable that the main component in at least the inside is silicon nitride. Since silicon nitride has both high thermal conductivity and high mechanical properties, it is effective when both of these properties are required.

In particular, of all components 100% by mass of the ceramic base plate 1, it is preferable that silicon nitride is 80% by mass or more. Examples of other components include at least one of erbium oxide, magnesium oxide, silicon oxide, molybdenum oxide, and aluminum oxide. As mechanical properties, it is preferable that the three-point bending strength is 750 MPa or more, the Young's modulus is 300 Gpa or more, the Vickers hardness (H _v ) is 13 GPa or more, and the fracture toughness (K _1C ) is 5 MPam ^1/2 or more. Ceramic base plate 1 the mechanical properties by this range can improve the durability against reliability, ie creep resistance and heat cycle.

However, the main component in this embodiment, of all components 100% by mass of the ceramic base plate 1, refers to a component accounting for at least 50 mass%.

As shown in FIG. 7, the heat radiating board 10 of the present embodiment, the binding layer 41 mainly composed of sequentially stacked active metal layers 31, 32 and copper on both principal surfaces of the ceramic base plate 1 And at least one copper plate mainly composed of copper or a copper alloy disposed on each of the bonding layers 41 and 42. The copper plate on one main surface is used as the circuit member 21, and the copper plate on the other main surface is used as the heat dissipation member 22. The radiating board 10 is a sintered body adjacent after sintering is easily detached, because of the use of ceramic board 1 mechanical properties is hardly impaired, a highly durable radiating board.

Circuit member 21 constituting the heat radiation board 10, for example, is 5mm or 60mm or less in length, width is 5mm or more 60mm or less. The thickness is determined by the magnitude of the current flowing through the circuit member 21, the amount of heat generated by an electronic component (not shown) mounted on the circuit member 21, and the thickness is, for example, 0.5 mm or more and 5 mm or less.

Further, the heat radiating member 22 configuring the heat radiating base plate 10 has the function of dissipating heat from a heating electronic component (not shown), for example, is 5mm or 60mm or less in length, width 5mm or 60mm or less, the thickness Is 0.5 mm or more and 5 mm or less.

Here, the copper plate containing copper or a copper alloy as a main component refers to a copper plate containing 90 mass% or more of copper or a copper alloy as a main component with respect to the circuit member 21 or the heat radiating member 22, and oxygen-free copper, It is preferable to use copper such as tough pitch copper or phosphorus deoxidized copper. In particular, among oxygen-free copper, it is preferable to use any of linear crystal oxygen-free, single-crystal high-purity oxygen-free copper, and vacuum-dissolved copper having a copper content of 99.995% by mass or more. This is because the higher the copper content, the lower the electrical resistance and the higher the thermal conductivity, so that the circuit characteristics (characteristics for suppressing the heat generation of electronic parts and reducing the power loss) and the heat radiation characteristics are excellent. In addition, the higher the copper content, the lower the yield stress and the easier the plastic deformation at high temperatures. Therefore, the bonding strength of the bonding layer 41, the circuit member 21, the bonding layer 42, and the heat dissipation member 22 increases, and more reliable. This is because the sex becomes higher.

  The copper plate in the present embodiment may be a thin sheet, for example, a copper foil.

Active metal layers 31 and 32 formed on both principal surfaces of the ceramic base plate 1 is, for example, titanium (Ti), zirconium (Zr), Ag containing active metals such as Group 4 element of hafnium (Hf) or the like It is made of a Cu alloy and bonds the circuit member 21 and the coupling layer 41, and the heat dissipation member 22 and the coupling layer 42, respectively.

As shown in FIG. 7, by providing the bonding layers 41 and 42 mainly composed of copper, the circuit member is formed at a low temperature of 300 ° C. or more and 500 ° C. or less by the diffusion action of copper which is the main component of the bonding layers 41 and 42. 21 and the heat radiating member 22 can be joined to the coupling layers 41 and 42, respectively. Further, since the bonding layers 41 and 42 are easily deformed, they can be joined even with a low load, and thermal stress generated during cooling can be relaxed by deformation. For this reason, a residual stress can be made small. Furthermore, a larger circuit member 21 or the warping be joined radiating member 22 hardly occurs in the thickness, it is possible to obtain an excellent heat radiation board 10 to heat dissipation characteristics. In some cases, a heat sink usually used for cooling an electronic component (not shown) can be eliminated.

  The bonding layers 41 and 42 containing copper as a main component are layers containing 90% by mass or more of copper as a main component with respect to the bonding layers 41 and 42, and the circuit member 21 and the heat dissipation member 22 are strengthened respectively. Join. These layers are preferably copper such as oxygen-free copper, tough pitch copper, and phosphorus deoxidized copper. In particular, among oxygen-free copper, it is preferable to use any of linear crystalline oxygen-free copper, single-crystal high-purity oxygen-free copper, and vacuum-melted copper having a copper content of 99.995% by mass or more.

Radiating board 10 of the present embodiment shown in FIG. 8, a bonding layer 41 composed mainly of sequentially stacked active metal layers 31, 32 and copper on both principal surfaces of the ceramic base plate 1, each And at least one copper plate mainly composed of copper or a copper alloy disposed on the bonding layers 41 and. Further, the copper plate on one of the main surfaces is used as the circuit member 21, and the copper plate on the other main surface is used as the heat radiating member 22, and the end surfaces 21 a and 22 a of the circuit member 21 and the heat radiating member 22 are coupled layers 31 and 32. It is characterized by being inside the respective end faces 31a, 32b.

As shown in FIG. 8, the end surfaces 21 a and 22 a of the circuit member 21 and the heat radiating member 22 are located inside the end surfaces 31 a and 32 a of the coupling layers 31 and 32, respectively. In the vicinity of 21a and 22a, the stress generated in the cooling step after heat bonding is easily relaxed in the bonding layers 31 and 32. Therefore, stress generated in the ceramic base plate 1 is reduced, it can be less heat dissipation board 10 with more warped. In particular, the distance between the end surface 21a of the circuit member 21 and the end surface 31a of the coupling layer 31 is 0.2 mm or more and 1 mm or less, and the distance between the end surface 22a of the heat dissipation member 22 and the end portion 32a of the coupling layer 32 is 0.2 mm or more and 1 mm or less. It is preferable that

The bonding layers 31 and 32 preferably have a Vickers hardness (H _v ) of 0.5 GPa or less. By setting the Vickers hardness (H _v ) of the bonding layers 31 and 32 to 0.5 GPa or less, the bonding layers 31 and 32 are easily elastically deformed, so that the bonding strength between the circuit member 21 and the heat dissipation member 22 is increased. Can do. In particular, the Vickers hardness (H _v ) is 0.2 GPa or more and 0
. More preferably, it is 5 GPa or less.

  Note that the Vickers hardness Hv of the bonding layers 31 and 32 may be measured in accordance with JIS Z 2244-2003, and the test load used for the measurement depends on the thickness of the bonding layers 31 and 32, for example, 98 mN (mm Newton) or 196 mN.

As shown in FIG. 9, the radiating board 10 in another embodiment, the heat radiating board 10 includes a ceramic base plate 1, the active metal layer 31 which are sequentially laminated on both main surfaces of the ceramic base plate 1 And bonding layers 41 and 42 mainly composed of copper, and at least one copper plate mainly composed of copper or a copper alloy disposed on each of the bonding layers 41 and 42. Moreover, the copper plate on one said main surface is used as the circuit member 21, the copper plate on the other said main surface is used as the heat radiating member 42, and the circuit member 21 is divided and arranged in a plurality of rows and a plurality of columns in plan view. It is characterized by.

Ceramic board 1, is 30mm or more 80mm or less length of the X direction shown in FIG. 9, the length of the Y-direction is at 10mm or more 80mm or less, the thickness varies depending on the application, but to suppress thermal resistance, durability From the viewpoint of maintaining the thickness, the thickness is preferably 0.13 mm or more and 0.64 mm or less. Such ceramic board 1, out of all components 100% constituting the ceramic base plate 1, it is preferable that silicon nitride is 80% by mass or more. As other additive components, at least one of erbium oxide, magnesium oxide, silicon oxide, molybdenum oxide, and aluminum oxide is included. As mechanical properties, it is preferable that the three-point bending strength is 750 MPa or more, the Young's modulus is 300 Gpa or more, the Vickers hardness (H _v ) is 13 GPa or more, and the fracture toughness (K _1C ) is 5 MPam ^1/2 or more. Ceramic base plate 1 the mechanical properties by this range can improve the durability against reliability, ie creep resistance and heat cycle.

Note that the three-point bending strength, the active metal layer 31 from the heat radiating board 10, bonding layer 41, after which the circuit member 21 and the heat radiating member 22 is removed by etching, in compliance with JIS R 1601-1995 Just measure. However, a small thickness of the ceramic base plate 1, if it is not possible to the thickness of the test piece cut out from the ceramic base plate 1 and 3 mm, the thickness of the ceramic base plate 1 may be a thickness of intact specimens.

As for the Young's modulus, after the active metal layer 31 from the heat radiating board 10, bonding layer 41, the circuit member 21 and the heat radiating member 22 is removed by etching, ultrasonic defined by JIS R 1602-1995 Measurement may be performed in accordance with the pulse method.
However, a small thickness of the ceramic base plate 1, if it is not possible to the thickness of the test piece cut out from the ceramic base plate 1 and 10 mm, the thickness of the ceramic base plate 1 may be a thickness of intact specimens.

The Vickers hardness (H _v ) and fracture toughness (K _1C ) may be measured according to the indenter press-in method (IF method) defined by JIS R 1610-2003 and JIS R 1607-1995, respectively. Incidentally, 0.5 mm specified in small thickness of the ceramic base plate 1, the thickness of the test piece cut from Seramimikku board 1, respectively JIS R 1610-2003, JIS R 1607-1995 indentation method (IF method), If it is not possible to 3mm, the result was evaluated thickness of the ceramic base plate 1 as the thickness of the intact specimens it is preferable to satisfy the above values. However, when the thickness of the ceramic base plate 1 is thin enough not able to satisfy the above values and evaluated as it thickness, pushing to change the load in accordance with the thickness of the ceramic base plate 1, on the basis of the result 0 Vickers hardness (Hv) and fracture toughness (K _1C ) at .5 mm and 3 mm may be estimated by simulation.

The volume resistivity as electrical properties, room temperature at ^{10 14 Ω} · cm or more and 300 ° C. at ^{10 12 Ω} · cm or more.

Active metal layers 31 and 32 formed on both principal surfaces of the ceramic base plate 1, for example, a titanium (Ti), zirconium (Zr), active metals such as Group 4 element such as hafnium (Hf) It consists of an Ag-Cu alloy, and couples the circuit member 21 and the coupling layer 41, and the heat dissipation member 22 and the coupling layer 42, respectively.

  The length in the X direction per one of the OO ′ lines of the active metal layers 31 and 32 is, for example, 12.4 mm to 24.4 mm, the length in the Y direction is 16.4 mm to 20.4 mm, and the thickness is 10 μm or more and 20 μm or less.

  Each circuit member 21 has a length in the X direction of 10 mm or more and 17 mm or less, a length in the Y direction of 10 mm or more and 20 mm or less, and the thickness of the circuit member 21 is the magnitude of the current flowing through the circuit member 21 or the electronic components mounted on the circuit member 21. It is determined by the amount of heat generated by a component (not shown), and is, for example, not less than 0.5 mm and not more than 5 mm.

  The heat dissipation member 22 has a function of releasing heat from a heated electronic component (not shown). For example, the length in the X direction is 10 mm or more and 17 mm or less, and the length in the Y direction is 10 mm or more. The thickness is 20 mm or less and the thickness is 0.5 mm or more and 5 mm or less.

Thus, when the circuit member 21 are disposed a plurality of rows, a plurality of rows in plan view, than the heat radiating board 10 on which a circuit element having the same number are arranged in one row or column, ceramic board One shape can be a square or a rectangle close to a square. Therefore, it is possible to suppress warpage of the heat radiation board 10 generated in the manufacturing process of the heat radiating board 10.

The warpage of the heat radiation board 10 will be described with reference to FIG. 10. 10 illustrates a plurality of rows, the heat radiating board 10 which is divided disposed in a plurality of columns circuit member 21 in plan view. FIG. 10 (b), the can shown in (d), the warpage of the heat radiation board 10 in any case substantially ceramic base plate 1 warpage. Total 1 line volume equal circuit member 21 in plan view has, compared with the heat radiating base plate 10 arranged in a plurality of rows, a plurality of rows of the circuit member 21, the heat radiating base plate 10 arranged in a plurality of rows, the ceramic base plate 1 The length in the longitudinal direction (X direction) can be shortened. Therefore, if a warp of the radius of curvature (R) is the same, warping _{(H 1)} that occur in the ceramic base plate 1 shown in FIG. 10 (b), occurs in the ceramic base plate 1 shown in FIG. 10 (d) The warpage (H ₂ ) can be made smaller.

The circuit member 21 preferably has a larger volume than the heat dissipation member 22. This is because it is possible to control the orientation of the warp generated in the heat radiating board 10 by the volume difference between the circuit member 21, the heat radiating member 22, the heat radiating board 10 of the present embodiment, circuit member 21 is heat radiation By making the volume per unit number larger than that of the member 22, the rigidity on the circuit member 21 side becomes higher than that on the heat radiating member 22 side. Therefore, the direction of the warp that occurs in the heat radiating board 1 0 can be controlled so as to be convex to the heat radiating member 22 side, it is possible to improve the adhesion between the heat dissipating member 22 sink (not shown) . Accordingly, the heat dissipation characteristics of the heat radiating board 10 can be further increased. In particular, when the number of circuit members 21 and heat radiating members 22 formed on both main surfaces is the same, and the circuit member 21 and the heat radiating members 22 are formed in corresponding positions, the volume difference per unit number is 20 mm ³ or more. More preferably.

Furthermore, the circuit member 21 is preferably harder than the heat dissipation member 22. It is possible to control the orientation of the warp circuit member 21, generated in the heat radiating board 10 by the hardness difference between the heat radiating member 22. The circuit member 21 has higher rigidity than the heat dissipation member 22, thereby increasing the rigidity of the heat dissipation member 21. Therefore, the direction of the warp that occurs in the heat dissipation board 10 can be controlled so as to be convex to the heat radiating member 22 side, it raised the adhesion between the heat dissipating member 22 and the heat sink (not shown). Accordingly, the heat dissipation characteristics of the heat radiating board 10 can be further increased. In particular, the Vickers hardness (Hv) of the circuit member 21 and the heat dissipation member 22 is preferably 0.7 GPa or more and 1.2 GPa or less, 0.5 GPa or more and 1.0 GPa or less, and the hardness difference thereof is preferably 0.2 GPa or more. is there.

  In addition, each volume of the circuit member 21 and the heat radiating member 22 can be measured using a three-dimensional shape measuring instrument or a metal microscope, an image measuring instrument, etc. by setting the magnification to 2 to 10 times. The Vickers hardness (Hv) of 22 may be measured in accordance with JIS Z 2244-2003, and the test load used for the measurement depends on the thicknesses of the circuit member 21 and the heat radiating member 22, for example, 196 mN (millinewton) And it is sufficient.

Radiating board 10 may be a heat radiating board 10 as shown in FIG. 11. According to this embodiment, the coupling layer 41 is partially formed over the plurality of circuit members 21, and the coupling layer 41 functions as a wiring connecting the plurality of circuit members 21. For this reason, the wiring by a wire becomes unnecessary and wiring is simplified.

Next, an example of a method of manufacturing the ceramic base plate 1 of the present embodiment.

If the main component of the ceramic base plate 1 is a silicon nitride, a is β ratio of siliceous nitride powder below 40%, the composition formula _{Si 6-Z Al Z O Z} N solid solution amount z of _8-Z is A ball nitride, a barrel mill, a rotary mill, a vibration mill, and a silicon nitride powder having a content of 0.5 or less and a powder comprising at least one of erbium oxide, magnesium oxide, silicon oxide, molybdenum oxide and aluminum oxide as an additive component , Bead-mixed using a bead mill, sand mill, agitator mill, etc., and pulverized into a slurry.

  Here, the total of the powder composed of at least one of erbium oxide, magnesium oxide, silicon oxide, molybdenum oxide and aluminum oxide, which are additive components, is the sum of the silicon nitride powder and the sum of the powders of these additive components. What is necessary is just to make it become 2-20 mass% when it is set as 100 volume%.

  There are two types of silicon nitride, α-type and β-type, due to the difference in crystal structure of silicon nitride. The α type is stable at low temperatures, the β type is stable at high temperatures, and the phase transition from α type to β type occurs irreversibly at 1400 ° C. or higher.

Here, the β conversion is the sum of the peak intensities of the α (102) diffraction line and the α (210) diffraction line obtained by the X-ray diffraction method, I _α , β (101) diffraction line and β ( 210) This is a value calculated by the following equation, where I _β is the sum of peak intensities with diffraction lines.

beta ratio _{= {I β / (I α} + I β)} × 100 (%) β ratio of silicon nitride powder affects the strength and fracture toughness of the ceramic base plate 1. The reason why a silicon nitride powder having a β conversion ratio of 40% or less is used is that both strength and fracture toughness can be increased. In particular, it is preferable to use a silicon nitride-based powder having a β conversion rate of 10% or less, whereby the solid solution amount z can be made 0.1 or more.

  The media used for pulverizing the silicon nitride-based powder can be media made of various ceramics such as silicon nitride, zirconia, and alumina. Is preferred.

Note that the silicon nitride powder is pulverized until the particle diameter (D ₉₀ ) at which the cumulative volume is 90% when the total cumulative volume of the particle size distribution curve is 100% is 3 μm or less. This is preferable from the viewpoints of improvement in cohesion and acicularization of the crystal structure. The particle size distribution obtained by grinding can be adjusted by the outer diameter of the media, the amount of the media, the viscosity of the slurry, the grinding time, and the like. In order to reduce the viscosity of the slurry, it is preferable to add a dispersant, and in order to pulverize in a short time, it is preferable to use a powder having a particle size (D ₅₀ ) of 1 μm or less that has a cumulative volume of 50% in advance.

  The obtained slurry is passed through a sieve having a particle size smaller than 200 mesh and then dried to obtain granules containing silicon nitride as a main component (hereinafter referred to as silicon nitride granules). For moldability, it is possible to mix an organic binder such as paraffin wax, polyvinyl alcohol (PVA), or polyethylene glycol (PEG) at a slurry level of 1% by mass or more and 10% by mass or less with respect to 100% by mass of the powder. Is preferable. The drying may be performed by a spray drying method using a spray dryer or the like, or may be another method.

Then, the silicon nitride granules are formed into a sheet by using a powder rolling method such as a roll compaction method to form a ceramic sheet, and the ceramic sheet is cut into a predetermined length to obtain a ceramic formed body . If the front surface to obtain a ceramic base plate 1 projecting 1c which forms a concavo-convex shape is formed repeatedly to multiple directions, by injecting the slurry with the viscosities in a predetermined amount or more to the syringe, the slurry of the ceramic molded body from the syringe A predetermined amount may be dropped on the surface of the substrate and dried.

Here, in the surface of the collision caused 1c hemispherical shape may be the viscosity of the slurry to be dropped on the surface of the ceramic body than 10 Pa · s.

Further, in order to obtain a ceramic base plate 1 which collision caused 1c are arranged at equal intervals, by placing a plurality of syringes at equal intervals, by dropping a predetermined amount of the slurry on the surface of the ceramic molded body, if dried Good.

Note that collision to the height of the raised 1c to obtain a ceramic base plate 1 is 16μm or more 52μm or less, it may be the height of the protrusions in the ceramic molded body to 20μm or 65μm or less.

The ceramic substrate of the present embodiment is obtained by laminating a plurality of ceramic molded bodies thus obtained in a firing furnace and holding the inside of the firing furnace in a nitrogen atmosphere at 1800 ° C. or more and 2000 ° C. or less for 5 to 40 hours. The board 1 can be obtained.

Next, a method for manufacturing the radiator board 10 of the present embodiment.

Radiating board 1 0 of the present embodiment, for example, is 30mm or more 80mm or less in length, width 10mm or more 80Mmmm, the thickness is 0.2mm or more 0.64mm on the following two main surfaces of the ceramic base plate 1, A paste of Ag—Cu alloy containing an active metal such as a group 4 element such as titanium (Ti), zirconium (Zr), hafnium (Hf) is applied by screen printing, roll coater method, brush coating, etc. After laminating a metal foil made of any one of copper, copper alloy, aluminum, aluminum alloy, molybdenum alloy, tungsten alloy and brass having a thickness of 0.1 mm or more and 0.6 mm or less, The active metal layers 31 and 32 and the bonding layers 41 and 42 are formed by heating and melting.

Next, the surfaces where the coupling layers 41 and 42 are in contact with the circuit member 21 and the heat radiating member 22 are polished, and the circuit members 21 and the heat radiating members 22 that are flat with the bonding layers 41 and 42 are bonded to, for example, 3 rows and 2 columns. And arranged in a matrix of 3 rows and 3 columns, and then heated to 300 ° C. or more and 500 ° C. or less in an atmosphere selected from an inert gas such as neon and argon, hydrogen and nitrogen, and 30 MP
at a pressure greater than or equal to a, it joined. The copper or copper alloy is cooled while pressurized to a temperature (50 ° C.) which is not oxidized, after reaching this temperature, exit pressure, to obtain a heat radiation board 10. As a specific method of forming the circuit of the circuit member 21, a copper plate that has been patterned by pressing or etching in advance to form a circuit may be used, or after bonding, patterning may be performed on the copper plate by etching, laser, or the like.

The resulting heat dissipating base plate 1 0 in the above-described manufacturing method, a sintered body adjacent after sintering is easily detached, a ceramic base plate 1 of this embodiment mechanical properties little impaired since it has, it may be a high heat dissipation board 10 durable.

Further, since the electronic apparatus of the present embodiment but is obtained by placing the various electronic components on the heat dissipation board 10, equipped with electronic components on the circuit member 21 in the high heat dissipation board 10 particularly durable, A highly durable electronic device can be obtained.

As described above, the heat radiating board 10 of this embodiment has a high street durability described above, insulated gate bipolar transistor (IGBT) devices, metal-oxide field effect transistor (MOSFET) device, a light emitting diode (LED) element, free wheeling diode (FWD) element, giant transistor (GTR) element and other semiconductor elements, sublimation type thermal printer head element, thermal ink jet printer head element, etc. The heat dissipation efficiency can be used with almost no decrease.

In addition, embodiment of this invention is not limited to the form mentioned above. For example, although described ceramic board having a plurality of impact force that have a concavo-convex of the average crystal grain size greater height than the crystals constituting the ceramic substrate, there may be depressions only.

Hereinafter, the case main component of the ceramic base plate 1 is an aluminum oxide, silicon nitride and aluminum nitride.

  First, aluminum oxide powder and various powders of magnesium oxide, calcium oxide and silicon oxide as additive components were wet-mixed using a ball mill and pulverized into a slurry.

  Here, the various powders of magnesium oxide, calcium oxide and silicon oxide are 0.15% by mass, 0.15% by mass and 0.2% by mass with respect to 100% by mass in total of the aluminum oxide powder and these various powders, respectively. %.

  Separately, silicon nitride powder having a β-conversion ratio of silicon nitride powder of 40% and erbium oxide powder as an additive component were wet-mixed using a ball mill, and pulverized into a slurry.

  Here, the erbium oxide powder was 8% by mass with respect to 100% by mass in total of the silicon nitride powder and the erbium oxide powder.

  Separately, aluminum nitride powder and various powders of neodymium oxide, ytterbium oxide and calcium oxide as additive components were wet-mixed using a ball mill, and pulverized into a slurry.

Here, the various powders of neodymium oxide, ytterbium oxide, and calcium oxide are 0.9% by mass, 1% by mass, and 0.9% by mass, respectively, with respect to the total amount of aluminum nitride powder and 100% by mass of these various powders. did.

  Then, each of the obtained slurries is passed through a sieve having a particle size of 250 mesh and dried to give granules mainly composed of aluminum oxide, silicon nitride, and aluminum nitride (hereinafter referred to as aluminum oxide granules, silicon nitride granules, (Referred to as aluminum nitride granules).

  In the slurry stage, polyvinyl alcohol (PVA) and polyethylene glycol (PEG) were mixed at 5% by mass with respect to 100% by mass of the powder.

  The aluminum oxide granule, silicon nitride granule and aluminum nitride granule are each formed into a sheet by roll compaction to form a ceramic sheet. The ceramic sheet is cut into a predetermined length, and the main components are oxidized. A ceramic molded body made of aluminum, silicon nitride, or aluminum nitride was obtained.

  And the ceramic shaping | molding in which the dimple 1d which the surface has repeatedly formed uneven | corrugated shape in multiple directions was formed by pressing the flat plate provided with the protrusion which has uneven | corrugated shape repeatedly in multiple directions to some ceramic molded bodies. Got the body.

  Note that for the hemispherical and conical samples whose dimples 1d have the shapes shown in Tables 1 and 2, the protrusions provided on the flat plate that presses the ceramic molded body were hemispherical and conical, respectively.

  In addition, in a part of the ceramic molded body on which the dimples 1d are formed, slurry containing the same component as the main component of the ceramic molded body is injected into a plurality of syringes, and the slurry is transferred from these syringes to the ceramic molded body. A predetermined amount was dropped on the surface and dried to form a protrusion 1c having a concavo-convex shape repeatedly in a plurality of directions.

  Further, in the remaining ceramic molded body, slurry containing the same component as the main component of the ceramic molded body is injected into a plurality of syringes, and a predetermined amount of slurry is dropped from the syringes onto the surface of the ceramic molded body. The ceramic molded body in which the protrusions 1c whose surface has a concavo-convex shape repeatedly formed in a plurality of directions was formed.

  Here, for the hemispherical and conical samples whose protrusions 1c have the shapes shown in Tables 1 and 2, the viscosities of the slurry dropped on the surface of the ceramic molded body were 10 Pa · s and 18 Pa · s, respectively.

  The ceramic molded body thus obtained was fired separately for each sample shown in Tables 1 and 2.

Specifically, for the ceramic molded body mainly composed of aluminum oxide, this ceramic molded body is shown in Sample Nos. 1 and 2 shown in Tables 1 and 2. Each, after stacking in a firing furnace by 10, the atmosphere air atmosphere in the firing furnace, the pressure of the atmosphere as a normal pressure to obtain a ceramic base plate 1 by holding 6 hours at 1600 ° C..

Further, for the ceramic molded body mainly composed of silicon nitride, this ceramic molded body is shown in Sample Nos. 1 and 2 shown in Tables 1 and 2. After stacking in a firing furnace by 10 pieces for each, air atmosphere the atmosphere in the firing furnace, the pressure of the atmosphere as a normal pressure to obtain a ceramic base plate 1 by holding 40 hours at 1970 ° C..

Further, for the ceramic molded body mainly composed of aluminum nitride, this ceramic molded body is shown in Sample Nos. 1 and 2 shown in Tables 1 and 2. After stacking in a firing furnace by 10 per atmosphere of nitrogen atmosphere in the firing furnace, the pressure of the atmosphere as a normal pressure to obtain a ceramic base plate 1 by holding at 1700 ° C. 10 hours.

Incidentally, after firing, since all samples were fixed ceramic board 1 together, from a point distant 50mm from the ceramic base plate 1 located in the central portion in the lamination direction, the pressure is fixed air 0.15MPa ceramic blown to board 1 5 seconds, it was counted and the number of the ceramic base plate 1 that is eliminated. Then, with respect to 10 pieces of the ceramic base plate 1, as shown in Tables 1 and 2 the ratio of the desorbed number of ceramic base plate 1 as the desorption rate. Sample No. Reference numerals 3 to 11, 36 to 44, and 69 to 77 are reference examples.

In Tables 1 and 2, and the type of irregularities a dimple, the sample between the dimples (distance of the center of a dimple and the center of its neighboring dimples) are shown as "equal", the projection ceramic board The first surface 1a is equally spaced in the longitudinal direction and the width direction. Further, the sample spacing of dimples each other is indicated as "unequal", the projection is irregularly spaced in the longitudinal direction and the width direction of the first surface 1a of the ceramic base plate 1. Here, the equal interval means that the difference between the dimples is 1 mm or less.

In Tables 1 and 2, a kind of uneven protrusions, the sample to which the interval is indicated as "equal" are equally spaced in the longitudinal direction and the width direction of the first surface 1a of the ceramic base plate 1 and are those using a syringe, sample the interval is indicated as "unequal" is use a syringe disposed at irregular intervals in the longitudinal direction and the width direction of the first surface 1a of the ceramic base plate 1 It was. In addition, the definition of equal intervals is between protrusions (the distance between the center of one protrusion and the center of the adjacent protrusion is 1 mm or less) as in the case where the type of unevenness is dimple.
In Tables 1 and 2, a type of irregularities dimples and protrusions, samples the interval is indicated as "equal", the projection is in the longitudinal direction and the width direction of the first surface 1a of the ceramic base plate 1 equal a flat plate which is formed in the interval, one using a syringe disposed at equal intervals in the longitudinal direction and the width direction of the first surface 1a of the ceramic base plate 1, the interval is shown as "unequal" samples unequal projection and flat plate are formed at equal intervals in the longitudinal direction and the width direction of the first surface 1a of the ceramic base plate 1, in the longitudinal direction and the width direction of the first surface 1a of the ceramic base plate 1 which are A syringe disposed at intervals is used.

Incidentally, after firing, since all samples were fixed ceramic board 1 together, from a point distant 50mm from the ceramic base plate 1 located in the central portion in the lamination direction, the pressure is fixed air 0.15MPa ceramic blown to board 1 5 seconds, it was counted and the number of the ceramic base plate 1 that is eliminated. Then, with respect to 10 pieces of the ceramic base plate 1, as shown in Tables 1 and 2 the ratio of the desorbed number of ceramic base plate 1 as the desorption rate.

Further, the average crystal grain size, bending the thermal conductivity and 3-point of the ceramic base plate 1 the intensity of the crystals constituting the ceramic base plate 1, according to JIS R 1670-2006, a laser flash method specified in JIS R 1611-1997 Measurements were made in accordance with a two-dimensional method and JIS R 1601-2008. However, a small thickness of the ceramic base plate 1, so could not be the thickness and 3mm cut out test pieces from the ceramic base plate 1, the thickness of the ceramic base plate 1 as the thickness of it is the test piece, 3 The point bending strength was measured.

Further, scanning with the electron microscope taken at 2000 × magnification cross-section including the surface of the ceramic base plate 1, the length 500 [mu] m, the maximum value of the height difference between the crest p and valley portions v adjacent pv, dimples The depth d of 1d and the height h of the protrusion 1c were measured. Here, the depth d of the dimple 1d and the height h of the protrusion 1c are average values of 10 pieces, respectively.

Next, by heat-treating the ceramic base plate 1 at 850 ° C., to remove the organic materials and residual carbon adhering to the surface of the ceramic base plate 1.

Added to the dimples and / or projections of the ceramic base plate 1, which is heat treated is formed plane, indium, added each powder of titanium and molybdenum, are mixed, the cellulose and terpineol silver and copper powder as a main component The paste obtained by kneading was applied by screen printing and then dried at 135 ° C. to form the metal layers 31 and 32 shown in FIG.

Then, a copper foil made of oxygen-free copper is placed in contact with the metal layers 31 and 32 and heated at 800 ° C. in a vacuum atmosphere, so that the circuit member 21 and the heat radiating member 22 pass through the metal layers 31 and 32, respectively. It is bonded to the ceramic base plate 1, to obtain a heat radiation board 10 shown in FIG.

Further, the ultrasonic flaw detection method, the measured plan view the area _{S v,} the ratio _{(= S v / S o ×} 100) to the area _{S o} of the surface heat dissipation member 22 is bonded to the ceramic base plate 1 Calculated as 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.

As shown in Tables 1 and 2, Sample No. 1, 2 , 12, 13, 23, 24, 34, 35, 45, 46, 56, 57, 67, 68, 78, 79, 89, 90 are based on the average crystal grain size of the crystals constituting the ceramic substrate 1. since without a collision force that having a unevenness of greater height, low desorption rate, not easily pulled apart the ceramic base plate 1 adjacent after firing.

On the other hand, sample no . 1 4～22,25～33, 4 7～55,58～66, 8 0～88,91～99 is that having a unevenness of greater height than the average grain size of crystals constituting the ceramic substrate 1 since it is provided with a collision force, high desorption rate was easily pulled apart the ceramic base plate 1 adjacent after firing.

As shown in Table 1, a sample composed mainly of ceramic base plate 1 is an aluminum oxide No. 14 to 22 and 25 to 33 are compared . 1 4～17,18～22,25～28,30～33, since from the surface of the collision force is formed in a semi-spherical shape, the residual stress after firing hardly remain in the sintered body, the three-point bending The strength was high and suitable.

Further, as shown in Table 1, a sample composed mainly of ceramic base plate 1 is an aluminum nitride No. Comparing 4 7～55,58～66 sample No. 4 7～50,52～55,58～60,62～66, since from the surface of the collision force is formed in a semi-spherical shape, the residual stress after firing hardly remain in the sintered body, the three-point bending The strength was high and suitable.

Further, as shown in Table 2, a sample composed mainly of ceramic base plate 1 is a silicon nitride No. Comparing the 8 0～88,91～99, sample No. 8 0～83,85～88,91～94,96～99, since from the surface of the collision force is formed in a semi-spherical shape, the residual stress after firing hardly remain in the sintered body, the three-point bending The strength was high and suitable.

Further, as shown in Table 1, samples No. 1 4～16,18～22,25～27,29～3 3, 47～49,51～55,58～60,62～66, 8 0～82,84～88,91～93,95～99 , since it is disposed at an equal interval in the collision outs predetermined direction, desorption ratio is higher, the more easily it pulled away the ceramic base plate 1 adjacent after firing.

Further, as shown in Table 1, the main component of the ceramic base plate 1 is an aluminum oxide, a sample only the height of the protrusions is different from No. When comparing 15, 16, 19, 20, and 21, sample no. 16,19,20, since the height of the projection is 16μm or more 52μm or less easily with Hikihanaseru the ceramic base plate 1 adjacent after firing, generated between the ceramic base plate 1 and the metal layer 32 There were few voids, which was suitable.

Further, as shown in Table 1, even when the main component of the ceramic base plate 1 is aluminum nitride or silicon nitride, collision height 16μm or 52μm following samples of causing the ceramic base plate 1 adjacent after firing together easily Hikihanaseru voids also less generated between the ceramic base plate 1 and the metal layer 32, it was suitable.

Furthermore, as shown in Table 2, samples No. 8 0～88,91～99, since the main component of the ceramic base plate 1 is a silicon nitride, see that combines high thermal conductivity and high mechanical properties, properties of both is obtained It is effective in some cases.

1: Ceramic board 10: radiator board 21: circuit member 22: heat dissipation members 31 and 32: the active metal layer 41: bonding layer

Claims (9)

A ceramic substrate having a plurality of protrusions on at least one main surface, wherein the protrusion has a maximum height difference between adjacent peak and valley bottoms from an average crystal grain size of crystals constituting the ceramic substrate. It has a size I凹 convex, a ceramic substrate, wherein the average height of the protrusions is 16μm or more 52μm or less.   The ceramic substrate according to claim 1, wherein a surface of the protrusion is formed in a hemispherical shape.   3. The ceramic substrate according to claim 1, wherein the protrusions are arranged at equal intervals in a predetermined direction.   4. The ceramic substrate according to claim 1, wherein the main component is silicon nitride.   A heat dissipation substrate, wherein a heat dissipation member is joined to the ceramic substrate according to claim 1.   A ceramic substrate according to any one of claims 1 to 4, a metal layer formed on a surface of the ceramic substrate on which a protrusion is formed, and a heat dissipation member disposed on the metal layer. Heat dissipation board.   An active metal layer and a bonding layer mainly composed of copper, which are sequentially laminated on both main surfaces of the ceramic substrate according to any one of claims 1 to 4, and copper or a copper alloy disposed on each bonding layer. And a copper plate on one main surface as a circuit member, and a copper plate on the other main surface as a heat radiating member.   The heat dissipation substrate according to claim 7, wherein the circuit members are arranged in a plurality of rows and a plurality of columns in a plan view.   An electronic device comprising an electronic component on the heat dissipation substrate according to claim 5.

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