Copper-ceramic bonded body and insulated circuit board

Abstract

A copper-ceramic bonded body (10, 110) in which a copper member (12, 13, 112, 113) comprising copper or a copper alloy is bonded to a ceramic member (11, 111), in which an active metal compound layer (31) or a magnesium oxide layer (131) is formed in a region on the copper member side of the ceramic member (11, 111). The active metal compound layer (31) contains a compound of one or more active metals selected from the group consisting of Ti, Zr, Nb and Hf, and transition metal layers (34, 134) containing one or more transition metals selected from the group consisting of V, Cr, Mn, Fe, Co, Ni, Mo, Ta and W are formed at the interface of the active metal compound layer (31) or the magnesium oxide layer (131) on the copper member side.

Description

Technical Field

[0001] The present invention relates to a copper-ceramic joint body formed by joining a copper component made of copper or a copper alloy to a ceramic component, and an insulating circuit substrate formed by joining a copper plate made of copper or a copper alloy to the surface of a ceramic substrate.

[0002] This application claims priority based on patent application No. 2022-143902 filed in Japan on September 9, 2022, patent application No. 2023-089701 filed in Japan on May 31, 2023, and patent application No. 2023-108414 filed in Japan on June 30, 2023, and the contents of which are incorporated herein by reference. Background Art

[0003] The power module, LED module and thermoelectric module have a structure in which a power semiconductor element, LED element and thermoelectric element are bonded to an insulating circuit substrate having a circuit layer made of a conductive material formed on one side of an insulating layer.

[0004] For example, high-power control power semiconductor elements used to control wind power generation, electric vehicles, hybrid vehicles, etc. generate a lot of heat during operation. Therefore, as a substrate for mounting the power semiconductor elements, the following insulating circuit substrate has been widely used. The insulating circuit substrate comprises: a ceramic substrate; a circuit layer formed by joining a metal plate with excellent conductivity to one side of the ceramic substrate; and a heat dissipation metal layer formed by joining a metal plate to the other side of the ceramic substrate.

[0005] For example, Patent Document 1 proposes an insulating circuit substrate, which is formed with a circuit layer and a metal layer by bonding a copper plate to one side and the other side of a ceramic substrate. In Patent Document 1, a copper plate is arranged on one side and the other side of a ceramic substrate via a Ag-Cu-Ti based brazing material, and the copper plates are bonded by performing a heat treatment (so-called active metal brazing method). In this active metal brazing method, since a brazing material containing Ti as an active metal is used, the wettability of the molten brazing material and the ceramic substrate is improved, and the ceramic substrate and the copper plate are well bonded.

[0006] Patent Document 1: Japanese Patent No. 3211856 (B)

[0007] However, there is a recent tendency for the heat generation temperature of semiconductor elements mounted on insulating circuit boards to increase. In addition, semiconductor devices having semiconductor elements mounted on insulating circuit boards are used as high-temperature operating devices capable of high-speed switching.

[0008] Therefore, since the insulating circuit substrate is subjected to thermal stress under high temperature conditions in a short period, higher thermal cycle reliability than before is required. Summary of the invention

[0009] The present invention has been completed in view of the above-mentioned situation, and its purpose is to provide a copper-ceramic joint body and an insulating circuit substrate composed of the copper-ceramic joint body, wherein the copper-ceramic joint body has excellent bonding properties between ceramic parts and copper parts and excellent thermal cycle reliability even when subjected to severe thermal cycles.

[0010] In order to solve the above-mentioned problems, the copper-ceramic joint body of aspect 1 of the present invention is formed by joining a copper part composed of copper or a copper alloy to a ceramic part, and the copper-ceramic joint body is characterized in that an active metal compound layer or a magnesium oxide layer is formed in the area on the copper part side of the ceramic part, and the active metal compound layer contains a compound of one or more active metals selected from Ti, Zr, Nb and Hf, and a transition metal layer containing one or more transition metals selected from V, Cr, Mn, Fe, Co, Ni, Mo, Ta and W is formed at the interface of the active metal compound layer or the magnesium oxide layer on the copper part side.

[0011] In the copper-ceramic joint body of aspect 1 of the present invention, a Mg solid solution layer may be formed in a region of the copper component on the ceramic component side, and the transition metal layer may be formed between the Mg solid solution layer and the active metal compound layer or the magnesium oxide layer.

[0012] In the copper-ceramic joint body of aspect 1 of the present invention, an active metal compound layer or a magnesium oxide layer is formed in the region of the ceramic component on the copper component side, a Mg solid solution layer is formed in the region of the copper component on the ceramic component side, and the transition metal layer is formed between the Mg solid solution layer and the active metal compound layer or the magnesium oxide layer.

[0013] Here, the active metal compound layer or the magnesium oxide layer, the Mg solid solution layer and the transition metal layer have high bonding properties, and the transition metal layer has higher bonding properties to copper than the active metal compound layer or the magnesium oxide layer. Therefore, a Mg solid solution layer is formed in the region on the ceramic component side of the copper component, and the transition metal layer exists between the Mg solid solution layer and the active metal compound layer or the magnesium oxide layer, thereby greatly improving the bonding reliability between the ceramic component and the copper component.

[0014] Therefore, in the copper-ceramic joint body of the first aspect of the present invention, even when subjected to a thermal cycle under high temperature conditions in a short period, the ceramic member and the copper member do not separate, and the thermal cycle reliability is particularly excellent.

[0015] The copper-ceramic bonded body according to claim 2 of the present invention is characterized in that, in the copper-ceramic bonded body according to claim 1, the active metal compound layer is a structure in which a plurality of active metal compound particles are aggregated.

[0016] The copper-ceramic joint body according to the third aspect of the present invention is characterized in that, in the copper-ceramic joint body according to the second aspect, a copper grain boundary phase exists between the active metal compound particles.

[0017] A copper-ceramic bonded body according to a fourth aspect of the present invention is the copper-ceramic bonded body according to the first aspect, wherein the magnesium oxide layer is a structure in which a plurality of magnesium oxide particles are aggregated.

[0018] The copper-ceramic joint body according to the fifth aspect of the present invention is characterized in that, in the copper-ceramic joint body according to the fourth aspect, a copper grain boundary phase exists between the magnesium oxide particles.

[0019] The insulating circuit substrate of aspect 6 of the present invention is formed by joining a copper plate composed of copper or a copper alloy to the surface of a ceramic substrate, and the insulating circuit substrate is characterized in that an active metal compound layer or a magnesium oxide layer is formed in the area on the copper plate side of the ceramic substrate, the active metal compound layer contains a compound of one or more active metals selected from Ti, Zr, Nb and Hf, a Mg solid solution layer is formed in the area on the ceramic substrate side of the copper plate, and a transition metal layer containing one or more transition metals selected from V, Cr, Mn, Fe, Co, Ni, Mo, Ta and W is formed between the Mg solid solution layer and the active metal compound layer or the magnesium oxide layer.

[0020] In the insulating circuit substrate of aspect 6 of the present invention, since an active metal compound layer or a magnesium oxide layer is formed in the area on the copper plate side of the ceramic substrate, a Mg solid solution layer is formed in the area on the ceramic substrate side of the copper plate, and a transition metal layer is formed between the Mg solid solution layer and the active metal compound layer or the magnesium oxide layer, the bonding reliability between the ceramic substrate and the copper plate is greatly improved.

[0021] Therefore, in the insulating circuit substrate of the sixth aspect of the present invention, even when subjected to a thermal cycle under high temperature conditions in a short period, the ceramic substrate and the copper plate will not peel off, and thermal cycle reliability is particularly excellent.

[0022] The insulating circuit substrate according to claim 7 of the present invention is characterized in that, in the insulating circuit substrate according to claim 6, the active metal compound layer has a structure in which a plurality of active metal compound particles are aggregated.

[0023] The insulating circuit board according to claim 8 of the present invention is characterized in that, in the insulating circuit board according to claim 7, a copper grain boundary phase exists between the active metal compound particles.

[0024] The insulating circuit substrate according to claim 9 of the present invention is characterized in that, in the insulating circuit substrate according to claim 6, the magnesium oxide layer has a structure in which a plurality of magnesium oxide particles are aggregated.

[0025] The insulating circuit board according to a tenth aspect of the present invention is characterized in that, in the insulating circuit board according to the ninth aspect, a copper grain boundary phase exists between the magnesium oxide particles.

[0026] The copper-ceramic joint body of aspect 11 of the present invention is formed by joining a copper part composed of copper or a copper alloy to a ceramic part, and the copper-ceramic joint body is characterized in that an active metal compound layer containing a compound of one or more active metals selected from Ti, Zr, Nb and Hf is formed in the area on the copper part side of the ceramic part, and a transition metal layer containing one or more transition metals selected from V, Cr, Mn, Fe, Co, Ni, Mo, Ta and W is formed at the interface on the copper part side of the active metal compound layer.

[0027] In the copper-ceramic joint body of aspect 11 of the present invention, an active metal compound layer is formed in the region on the copper component side of the ceramic component, and a transition metal layer is formed at the interface of the active metal compound layer on the copper component side. Here, the active metal compound layer and the transition metal layer have high matching properties, and the transition metal layer has higher matching properties with copper than the active metal compound layer, so the presence of the transition metal layer between the active metal compound layer formed in the region on the copper component side of the ceramic component and the copper component can greatly improve the bonding reliability between the ceramic component and the copper component.

[0028] Therefore, in the copper-ceramic joint body of the eleventh aspect of the present invention, even when subjected to a thermal cycle under high temperature conditions in a short period, the ceramic component and the copper component do not peel off, and the thermal cycle reliability is particularly excellent.

[0029] The copper-ceramic joint body according to aspect 12 of the present invention is characterized in that, in the copper-ceramic joint body according to aspect 11, the transition metal layer contains one or two or more transition metals selected from V, Cr, Mn, Fe, Co and Ni.

[0030] According to the copper-ceramic joint body of aspect 12 of the present invention, the transition metal layer contains one or more transition metals selected from V, Cr, Mn, Fe, Co and Ni, so the bonding reliability between the ceramic component and the copper component is reliably improved.

[0031] The copper-ceramic joint body of aspect 13 of the present invention is characterized in that, in the copper-ceramic joint body of aspect 11 or aspect 12, a Cu-Ag layer containing a Cu phase and an Ag phase is formed in the area on the ceramic part side of the copper part, and the transition metal layer is formed between the Cu phase and the Ag phase and the active metal compound layer.

[0032] According to the copper-ceramic joint body of aspect 13 of the present invention, the transition metal layer has a high matching property with the Cu phase and the Ag phase, and even when a Cu-Ag layer containing the Cu phase and the Ag phase is formed in the area on the ceramic component side of the copper component, the bonding reliability between the ceramic component and the copper component will be greatly improved.

[0033] The insulating circuit substrate of aspect 14 of the present invention is formed by joining a copper plate composed of copper or a copper alloy to the surface of a ceramic substrate, and the insulating circuit substrate is characterized in that an active metal compound layer containing a compound of one or more active metals selected from Ti, Zr, Nb and Hf is formed in the area on the copper plate side of the ceramic substrate, and a transition metal layer containing one or more transition metals selected from V, Cr, Mn, Fe, Co, Ni, Mo, Ta and W is formed at the interface on the copper plate side of the active metal compound layer.

[0034] In the insulating circuit substrate of aspect 14 of the present invention, an active metal compound layer is formed in the area on the copper plate side of the ceramic substrate, and a transition metal layer is formed at the interface on the copper plate side of the active metal compound layer, so that the bonding reliability between the ceramic substrate and the copper plate is greatly improved.

[0035] Therefore, in the insulating circuit substrate of the fourteenth aspect of the present invention, even when subjected to a thermal cycle under high temperature conditions in a short period, the ceramic substrate and the copper plate will not be separated, and thermal cycle reliability is particularly excellent.

[0036] The insulating circuit substrate of aspect 15 of the present invention is characterized in that, in the insulating circuit substrate of aspect 14, the transition metal layer contains one or more transition metals selected from V, Cr, Mn, Fe, Co and Ni.

[0037] According to the insulating circuit substrate of aspect 15 of the present invention, the transition metal layer contains one or more transition metals selected from V, Cr, Mn, Fe, Co and Ni, so the bonding reliability between the ceramic substrate and the copper plate is reliably improved.

[0038] The insulating circuit substrate of aspect 16 of the present invention is characterized in that, in the insulating circuit substrate of aspect 14 or aspect 15, a Cu-Ag layer comprising a Cu phase and an Ag phase is formed in the area on the ceramic substrate side of the copper plate, and the transition metal layer is formed between the Cu phase and the Ag phase and the active metal compound layer.

[0039] According to the insulating circuit substrate of aspect 16 of the present invention, the transition metal layer has a high matching property with the Cu phase and the Ag phase, and even when a Cu-Ag layer containing the Cu phase and the Ag phase is formed in the area on the ceramic substrate side of the copper plate, the bonding reliability between the ceramic substrate and the copper plate will be greatly improved.

[0040] According to the present invention, a copper-ceramic bonded body having excellent bonding properties between a ceramic component and a copper component and excellent thermal cycle reliability even when subjected to severe thermal cycles and an insulating circuit substrate composed of the copper-ceramic bonded body can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic explanatory diagram of a power module using an insulating circuit substrate according to an embodiment of the present invention.

[0042] Figure 2 It is an enlarged explanatory diagram of a bonding interface between a circuit layer and a metal layer of an insulating circuit board according to the first embodiment of the present invention and a ceramic substrate.

[0043] Figure 3 This is a flowchart of the method for manufacturing the insulating circuit board according to the first embodiment of the present invention.

[0044] Figure 4 It is a schematic explanatory diagram of the method for manufacturing the insulating circuit board according to the first embodiment of the present invention.

[0045] Figure 5 It is a schematic explanatory diagram of an insulating circuit substrate according to a second embodiment of the present invention.

[0046] Figure 6 It is an enlarged explanatory diagram of a bonding interface between a circuit layer and a metal layer of an insulating circuit board according to a second embodiment of the present invention and a ceramic substrate.

[0047] Fig. 7A It is an explanatory diagram of the surface cutting test in the example.

[0048] Figure 7B It is an explanatory diagram of the surface cutting test in the example.

[0049] Figure 8This is a photograph of the observed bonding interface of the insulating circuit substrate of Invention Example A1 in the Examples.

[0050] Fig. 9 This is a photograph showing the observed bonding interface of the insulating circuit substrate of Invention Example A2 in the Examples. DETAILED DESCRIPTION

[0051] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0052] (First Embodiment)

[0053] The copper-ceramic joint body involved in the first embodiment of the present invention is an insulating circuit substrate 10, which is formed by joining a ceramic substrate 11 as a ceramic component composed of ceramic, a copper plate 22 (circuit layer 12) as a copper component composed of copper or a copper alloy, and a copper plate 23 (metal layer 13). Figure 1 2 shows a power module 1 including an insulating circuit substrate 10 according to the present embodiment.

[0054] The power module 1 comprises: an insulating circuit substrate 10 provided with a circuit layer 12 and a metal layer 13; Figure 1 The semiconductor element 3 is bonded via the bonding layer 2; and the other side ( Figure 1 Radiator 5 (lower side in the middle).

[0055] The semiconductor element 3 is made of a semiconductor material such as Si, and is bonded to the circuit layer 12 via the bonding layer 2 .

[0056] The bonding layer 2 is made of, for example, a Sn—Ag-based, Sn—In-based, or Sn—Ag—Cu-based solder material.

[0057] The heat sink 5 is used to dissipate heat from the insulating circuit substrate 10. The heat sink 5 is made of copper or a copper alloy, and in this embodiment, is made of phosphorus deoxidized copper. The heat sink 5 is provided with a flow path through which a cooling fluid flows.

[0058] In the present embodiment, the heat sink 5 and the metal layer 13 are bonded to each other via a solder layer 7 made of a solder material. The solder layer 7 is made of, for example, a Sn-Ag-based, Sn-In-based, or Sn-Ag-Cu-based solder material.

[0059] And, if Figure 1 As shown, the insulating circuit substrate 10 of this embodiment includes: a ceramic substrate 11; a surface ( Figure 1 and disposed on the other side of the ceramic substrate 11 ( Figure 1The metal layer 13 is shown below.

[0060] The ceramic substrate 11 is made of ceramics such as silicon nitride (Si3N4), aluminum nitride (AlN), and aluminum oxide (Al2O3) that have excellent insulation and heat dissipation properties. In the present embodiment, the ceramic substrate 11 is made of aluminum nitride (AlN) that has particularly excellent heat dissipation properties. In addition, the thickness of the ceramic substrate 11 is set, for example, within a range of 0.2 mm to 1.5 mm, and is set to 0.635 mm in the present embodiment.

[0061] like Figure 4 As shown, the circuit layer 12 is formed on one side of the ceramic substrate 11 ( Figure 4 The upper surface is joined to a copper plate 22 made of copper or a copper alloy.

[0062] In the present embodiment, the circuit layer 12 is formed by bonding a rolled plate of oxygen-free copper to the ceramic substrate 11 .

[0063] The thickness of the copper plate 22 that becomes the circuit layer 12 is set within a range of 0.1 mm to 2.0 mm, and is set to 0.25 mm in the present embodiment.

[0064] like Figure 4 As shown, the metal layer 13 is formed on the other side of the ceramic substrate 11 ( Figure 4 The bottom is formed by joining a copper plate 23 made of copper or a copper alloy.

[0065] In the present embodiment, the metal layer 13 is formed by bonding a rolled plate of oxygen-free copper to the ceramic substrate 11 .

[0066] The thickness of the copper plate 23 that becomes the metal layer 13 is set within a range of 0.1 mm to 2.0 mm, and is set to 0.25 mm in the present embodiment.

[0067] Here, Figure 2 2 is an enlarged view of the vicinity of the bonding interface between the ceramic substrate 11 and the circuit layer 12 (metal layer 13 ).

[0068] An active metal compound layer 31 including a compound of one or two or more active metals selected from Ti, Zr, Nb, and Hf is formed in a region on the circuit layer 12 (metal layer 13 ) side of the ceramic substrate 11 .

[0069] The active metal compound layer 31 is a layer formed by the active metal (Ti, Zr, Nb, Hf) used when bonding the ceramic substrate 11 and the copper plate 22 (copper plate 23) diffused into the ceramic substrate 11 and reacting with the constituent elements of the ceramic substrate 11, and becomes a part of the ceramic substrate 11.

[0070] More specifically, when the ceramic substrate is made of silicon nitride (Si3N4) or aluminum nitride (AlN), the active metal compound layer 31 is a layer made of nitrides of these active metals. When the ceramic substrate is aluminum oxide (Al2O3), it is a layer containing oxides of these active metals.

[0071] And, if Figure 2 As shown, the active metal compound layer 31 is a structure in which a plurality of active metal compound particles 32 are aggregated, and a copper grain boundary phase 33 exists between these active metal compound particles 32 .

[0072] In the present embodiment, Ti is used as the active metal used in bonding, and the ceramic substrate 11 is composed of silicon nitride (Si 3 N 4 ), so the active metal compound layer 31 is mainly composed of titanium nitride (TiN).

[0073] Furthermore, in the present embodiment, the active metal compound layer 31 is a layer formed by aggregation of a plurality of titanium nitride particles (active metal compound particles 32 ) having an average particle diameter of 10 nm to 100 nm.

[0074] Moreover, a transition metal layer 34 containing one or more transition metals selected from V, Cr, Mn, Fe, Co, Ni, Mo, Ta and W is formed at the interface on the circuit layer 12 (metal layer 13) side in the active metal compound layer 31.

[0075] The transition metal layer 34 may include one or more transition metals selected from V, Cr, Mn, Fe, Co, and Ni.

[0076] In addition, the transition metal layer 34 can be formed not only at the interface on the circuit layer 12 (metal layer 13) side in the active metal compound layer 31, but also at the interface between the active metal compound particles 32 and the copper grain boundary phase 33. That is, the transition metal layer 34 can be formed on the outer peripheral surface of the active metal compound particles 32 constituting the active metal compound layer 31.

[0077] Furthermore, in the present embodiment, the Mg solid solution layer 36 is formed in the region of the circuit layer 12 (metal layer 13 ) on the ceramic substrate 11 side.

[0078] The Mg solid solution layer 36 is formed by diffusion of Mg contained in a bonding material used when bonding the ceramic substrate 11 and the copper plate 22 (copper plate 23) to the copper plate 22 (copper plate 23) side, and becomes a part of the circuit layer 12 (metal layer 13).

[0079] In the region on the ceramic substrate 11 side of the circuit layer 12 (metal layer 13 ), a Cu—Ag layer including a Cu phase and an Ag phase may be formed in place of the Mg solid solution layer 36 or in a manner overlapping with the Mg solid solution layer 36 .

[0080] The Cu—Ag layer 36 is formed by diffusing Ag contained in a bonding material used when bonding the ceramic substrate 11 and the copper plate 22 (copper plate 23 ) to the copper plate 22 (copper plate 23 ) side, and becomes a part of the circuit layer 12 (metal layer 13 ).

[0081] Here, the Cu—Ag layer 36 includes a Cu phase and an Ag phase, but the transition metal layer 34 is formed between the Cu phase and the active metal compound layer 31 (active metal compound particles 32 ) and between the Ag phase and the active metal compound layer 31 (active metal compound particles 32 ).

[0082] In addition, the copper grain boundary phase 33 formed between the plurality of active metal compound particles 32 may contain Ag. In this case, a transition metal layer 34 may be formed between Cu of the copper grain boundary phase 33 and the active metal compound layer 31 (active metal compound particles 32), and between Ag of the copper grain boundary phase 33 and the active metal compound layer 31 (active metal compound particles 32).

[0083] Here, in the Mg solid solution layer 36 , when the total of Cu, Mg, active metals, and transition metals is 100 atomic %, the Mg concentration is in the range of 0.05 atomic % to 6.9 atomic % both inclusive.

[0084] In addition, the Mg solid solution layer 36 may contain an intermetallic compound (for example, Cu2Mg, CuMg2, etc.) having a Mg concentration in the range of 30 atomic % to 70 atomic %.

[0085] Here, in the present embodiment, the thickness of the active metal compound layer 31 is preferably within a range of 0.05 μm to 1.2 μm.

[0086] Furthermore, in the present embodiment, the thickness of the Mg solid solution layer 36 is preferably in the range of more than 0 μm and 200 μm or less, and more preferably 50 μm or more and 120 μm or less.

[0087] The thickness of the Cu—Ag layer 36 may be in the range of 0 μm or more and 15 μm or less.

[0088] Furthermore, in the present embodiment, the thickness of the transition metal layer 34 is preferably within a range of 1 nm to 15 nm.

[0089] Below, reference Figure 3 and Figure 4, a method for manufacturing the insulating circuit substrate 10 according to the present embodiment will be described.

[0090] (Jointing Material Arrangement Step S01)

[0091] First, prepare a ceramic substrate 11, such as Figure 4 As shown, Mg, Cu, active metals (Ti, Zr, Nb, Hf), and transition metals (V, Cr, Mn, Fe, Co, Ni, Mo, Ta, and W) are arranged as bonding materials 25 between the copper plate 22 forming the circuit layer 12 and the ceramic substrate 11, and between the copper plate 23 forming the metal layer 13 and the ceramic substrate 11.

[0092] Alternatively, Ag, Cu, active metals (Ti, Zr, Nb, Hf), and transition metals (V, Cr, Mn, Fe, Co, Ni, Mo, Ta, and W) are provided as the bonding material 25 .

[0093] Here, in the bonding material disposing step S01, the disposing amounts of Mg (or Ag), Cu, active metal, and transition metal are preferably set as follows: In addition, Cu (or Ag, Cu) may not be disposed as long as the ceramic substrate 11 and the copper plate 22 (copper plate 23) can be bonded.

[0094] Mg: 14.3 μmol / cm 2 Above 71.5 μmol / cm 2 the following

[0095] Cu: 0 μmol / cm 2 Above 70.5 μmol / cm 2 the following

[0096] Active metal: 0.8 μmol / cm 2 Above 18.8 μmol / cm 2 the following

[0097] Transition metals: 1.0 μmol / cm 2 Above and 15.0 μmol / cm 2 the following

[0098] or

[0099] Ag: 0 μmol / cm 2 Above 97.3 μmol / cm 2 the following

[0100] Cu: 0 μmol / cm 2 Above 77.8 μmol / cm 2 the following

[0101] Active metal: 0.8 μmol / cm 2 Above 18.8 μmol / cm 2 the following

[0102] Transition metals: 1.5 μmol / cm 2 Above and 15.0 μmol / cm 2 the following

[0103] (Lamination Step S02)

[0104] Next, the copper plate 22 and the ceramic substrate 11 are stacked via the bonding material 25 (Mg (or Ag), Cu, active metal, transition metal), and the ceramic substrate 11 and the copper plate 23 are stacked via the bonding material 25 (Mg (or Ag), Cu, active metal, transition metal).

[0105] (Joining process S03)

[0106] Next, the stacked copper plate 22, bonding material 25 (Mg (or Ag), Cu, active metal, transition metal), ceramic substrate 11, bonding material 25 (Mg (or Ag), Cu, active metal, transition metal) and copper plate 23 are pressurized in the stacking direction and placed in a vacuum furnace for heating to bond the copper plate 22, ceramic substrate 11 and copper plate 23.

[0107] At this time, each element of the bonding material 25 diffuses to the copper plates 22 and 23 or the ceramic substrate 11 to form a Mg solid solution layer 36 and an active metal compound layer 31, so there is no bonding layer between the ceramic substrate 11 and the circuit layer 12 (metal layer 13).

[0108] Here, the heating temperature in the joining process S03 is preferably in the range of 750°C to 950°C, and the total of the temperature integral values ​​in the heating process from 740°C to the heating temperature and the holding process at the heating temperature is preferably in the range of 30°C·h to 500°C·h.

[0109] In addition, the pressurizing load P in the joining step S03 is preferably in the range of 0.098 MPa to 1.47 MPa.

[0110] Here, when Ag is provided, the heating temperature in the joining process S03 is preferably in the range of not less than 810°C and not more than 900°C, and the total of the temperature integral values ​​in the heating process from 800°C to the heating temperature and the holding process at the heating temperature is preferably in the range of not less than 20°C·h and not more than 5000°C·h.

[0111] Furthermore, in the absence of Ag, the heating temperature in the joining process S03 is preferably in the range of not less than 900°C and not more than 1050°C, and the total of the temperature integral values ​​in the heating process from 890°C to the heating temperature and the maintaining process at the heating temperature is preferably in the range of not less than 20°C·h and not more than 5000°C·h.

[0112] As described above, the insulating circuit board 10 according to the present embodiment is manufactured through the bonding material disposing step S01 , the laminating step S02 , and the bonding step S03 .

[0113] (Heat sink bonding process S04)

[0114] Next, the heat sink 5 is bonded to the other surface side of the metal layer 13 of the insulating circuit board 10 .

[0115] The insulating circuit substrate 10 and the heat sink 5 are stacked with a solder material interposed therebetween and placed in a heating furnace, whereby the insulating circuit substrate 10 and the heat sink 5 are solder-joined with each other via the solder layer 7 .

[0116] (Semiconductor element bonding step S05)

[0117] Next, the semiconductor element 3 is bonded to one surface of the circuit layer 12 of the insulating circuit substrate 10 by soldering.

[0118] Through the above process, the Figure 1 The power module 1 is shown.

[0119] According to the insulating circuit substrate 10 (copper-ceramic joint body) of the present embodiment having the structure as described above, an active metal compound layer 31 is formed in the region on the circuit layer 12 (metal layer 13) side of the ceramic substrate 11, and a transition metal layer 34 is formed at the interface of the circuit layer 12 (metal layer 13) in the active metal compound layer 31, so that the bonding reliability between the ceramic substrate 11 and the circuit layer 12 (metal layer 13) is greatly improved.

[0120] Furthermore, in the insulating circuit substrate 10 of the present embodiment, a Mg solid solution layer 36 (or Cu-Ag layer 36) is formed in the area on the ceramic substrate 11 side of the circuit layer 12 (metal layer 13), and when a transition metal layer 34 is formed between the Mg solid solution layer 36 (Cu phase and Ag phase) and the active metal compound layer 31, the bonding reliability between the ceramic substrate 11 and the circuit layer 12 (metal layer 13) is greatly improved.

[0121] (Second Embodiment)

[0122] The copper-ceramic joint body involved in the second embodiment of the present invention is an insulating circuit substrate 110, which is formed by joining a ceramic substrate 111 as a ceramic component composed of ceramic, a copper plate (circuit layer 112) as a copper component composed of copper or a copper alloy, and a copper plate (metal layer 113).

[0123] In the present embodiment, the ceramic substrate 111 is made of alumina (Al 2 O 3 ) which has excellent insulation and heat dissipation properties.

[0124] Furthermore, the thickness of the ceramic substrate 111 is set, for example, within a range of 0.2 mm to 1.5 mm, and is set to 0.635 mm in the present embodiment.

[0125] The circuit layer 112 is formed by bonding a copper plate made of copper or a copper alloy to one surface of the ceramic substrate 111 .

[0126] In the present embodiment, the circuit layer 112 is formed by bonding a rolled plate of oxygen-free copper to the ceramic substrate 111 .

[0127] The thickness of the copper plate that becomes the circuit layer 112 is set within a range of 0.1 mm to 2.0 mm, and is set to 0.25 mm in the present embodiment.

[0128] The metal layer 113 is formed by bonding a copper plate made of copper or a copper alloy to the other surface of the ceramic substrate 111 .

[0129] In the present embodiment, the metal layer 113 is formed by bonding a rolled plate of oxygen-free copper to the ceramic substrate 111 .

[0130] The thickness of the copper plate that becomes the metal layer 113 is set within a range of 0.1 mm to 2.0 mm, and is set to 0.25 mm in the present embodiment.

[0131] Here, Figure 6 2 is an enlarged view of the vicinity of the bonding interface between the ceramic substrate 111 and the circuit layer 112 (metal layer 113 ).

[0132] A magnesium oxide layer 131 is formed in a region of the ceramic substrate 111 on the circuit layer 112 (metal layer 13 ) side.

[0133] The magnesium oxide layer 131 is a layer formed by diffusing Mg used when bonding the ceramic substrate 111 and the copper plate into the ceramic substrate 111 and reacting with oxygen in the ceramic substrate 111 , and becomes a part of the ceramic substrate 111 .

[0134] like Figure 6As shown, the magnesium oxide layer 131 is a structure in which magnesium oxide particles 132 are aggregated, and copper grain boundary phases 133 exist between these magnesium oxide particles 132 .

[0135] In the present embodiment, the average particle diameter of the magnesium oxide particles 132 constituting the magnesium oxide layer 131 is preferably in the range of 10 nm to 100 nm. The magnesium oxide particles 132 are made of, for example, MgO or MgAl2O4.

[0136] Moreover, a transition metal layer 134 containing one or more transition metals selected from V, Cr, Mn, Fe, Co, Ni, Mo, Ta and W is formed at the interface on the circuit layer 12 (metal layer 13) side in the magnesium oxide layer 131.

[0137] In addition, the transition metal layer 134 can be formed not only at the interface on the circuit layer 112 (metal layer 113) side in the magnesium oxide layer 131, but also at the interface between the magnesium oxide particles 132 and the copper grain boundary phase 133. That is, the transition metal layer 134 can be formed on the outer peripheral surface of the magnesium oxide particles 132 constituting the magnesium oxide layer 131.

[0138] Furthermore, in the present embodiment, the Mg solid solution layer 136 is formed in the region of the circuit layer 112 (metal layer 113 ) on the ceramic substrate 111 side.

[0139] The Mg solid solution layer 136 is a layer formed by diffusion of Mg contained in a bonding material used when bonding the ceramic substrate 111 and the copper plate to the copper plate side, and becomes a part of the circuit layer 112 (metal layer 113 ).

[0140] Here, in the Mg solid solution layer 136 , when the total of Cu, Mg, active metals, and transition metals is 100 atomic %, the Mg concentration is in the range of 0.05 atomic % to 6.9 atomic % both inclusive.

[0141] In addition, the Mg solid solution layer 136 may contain an intermetallic compound (eg, Cu2Mg, CuMg2, etc.) having a Mg concentration in the range of 30 atomic % to 70 atomic %.

[0142] Here, in the present embodiment, the thickness of the magnesium oxide layer 131 is preferably within a range of 0.05 μm to 1.2 μm.

[0143] Furthermore, in the present embodiment, the thickness of the Mg solid solution layer 136 is preferably in the range of more than 0 μm and 200 μm or less, and more preferably 50 μm or more and 120 μm or less.

[0144] Furthermore, in the present embodiment, the thickness of the transition metal layer 134 is preferably within a range of 1 nm to 15 nm.

[0145] The insulating circuit substrate 110 of the second embodiment is similar to the first embodiment. Figure 3 and Figure 4 The manufacturing method shown in FIG. 1 is to be used for manufacturing, that is, a bonding material disposing step S01, a laminating step S02, and a bonding step S03.

[0146] According to the insulating circuit substrate 110 (copper-ceramic joint body) of the present embodiment having the structure as described above, a magnesium oxide layer 131 is formed in the region on the circuit layer 112 (metal layer 113) side of the ceramic substrate 111, and a transition metal layer 134 is formed at the interface of the circuit layer 112 (metal layer 113) in the magnesium oxide layer 131, so that the bonding reliability between the ceramic substrate 111 and the circuit layer 112 (metal layer 113) is greatly improved.

[0147] Furthermore, in the insulating circuit substrate 110 of the present embodiment, a Mg solid solution layer 136 is formed in the area on the ceramic substrate 111 side of the circuit layer 112 (metal layer 113), and a transition metal layer 134 is formed between the Mg solid solution layer 136 and the magnesium oxide layer 131. The bonding reliability between the ceramic substrate 111 and the circuit layer 112 (metal layer 113) is greatly improved.

[0148] As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably within the range which does not deviate from the technical idea of ​​this invention.

[0149] For example, in this embodiment, a case where a semiconductor element is mounted on an insulating circuit substrate to form a power module is described, but the present invention is not limited thereto. For example, an LED element may be mounted on a circuit layer of an insulating circuit substrate to form an LED module, or a thermoelectric element may be mounted on a circuit layer of an insulating circuit substrate to form a thermoelectric module.

[0150] Furthermore, in the insulating circuit substrate of the present embodiment, an example of a ceramic substrate composed of aluminum nitride (AlN) and aluminum oxide (Al2O3) is given for explanation, but the present invention is not limited to this, and other ceramic substrates such as silicon nitride (Si3N4) may also be used.

[0151] In addition, in this embodiment, the case where a circuit layer is formed by joining a rolled plate of oxygen-free copper to a ceramic substrate is described, but this is not limited to this. A circuit layer can also be formed by joining a copper sheet formed by stamping a copper plate to a ceramic substrate in a circuit pattern configuration.

[0152] Example

[0153] (Example 1)

[0154] Hereinafter, the results of confirmation experiments conducted to confirm the effects of the present invention will be described.

[0155] First, ceramic substrates (40 mm×40 mm) were prepared as shown in Tables 1 to 3. The thickness was 0.635 mm for AlN and Al2O3, and 0.32 mm for Si3N4.

[0156] Furthermore, as a copper plate to be used as a circuit layer and a metal layer, a copper plate of 37 mm×37 mm made of oxygen-free copper and having a thickness of 0.25 mm was prepared.

[0157] Then, each element shown in Table 1 was disposed between the ceramic substrate and the copper plate as a bonding material to obtain a laminate of copper plate-ceramic substrate / copper plate.

[0158] Next, the copper plate and the ceramic substrate were bonded together under the conditions shown in Tables 4 to 6 to obtain insulating circuit substrates (copper-ceramic bonded bodies) of Inventive Examples 1 to 8, 11 to 14, 21 to 24, and Comparative Examples 1, 11, and 21.

[0159] The obtained insulating circuit substrate (copper-ceramic bonded body) was subjected to observation of the bonding interface.

[0160] The obtained insulating circuit board (copper-ceramic joint body) was subjected to 500 cycles of thermal cycling in a liquid bath under the conditions of -40°C×5min←→150°C×5min. Then, surface cutting was performed.

[0161] (Observation of Active Metal Compound Layer)

[0162] The obtained insulating circuit substrate (copper-ceramic joint body) was collected and observed by a scanning electron microscope (GeminiSEM 500 manufactured by Carl Zeiss AG) with an accelerating voltage of 7 kV and a magnification of 30,000 times to observe the cross-section of the bonding interface between the copper plate and the ceramic substrate in the range of 3 μm in height × 4 μm in width. There was an area where active metal and nitrogen (N) coexisted. When the total of active metal and nitrogen (N) in this area was set to 100 atomic %, the area where the concentration of active metal was more than 20 atomic % was judged as an active metal compound layer, and the area of ​​the area was measured. In addition, the active metal compound layer is part of the ceramic component. The thickness of the active metal compound layer is calculated by dividing the measured area by the width of the field of view. The measurements were carried out in five fields of view, and the average values ​​are shown in Tables 4 to 6.

[0163] (Observation of magnesium oxide layer)

[0164] The obtained insulating circuit substrate (copper-ceramic joint body) was collected and observed by a scanning electron microscope (GeminiSEM 500 manufactured by Carl Zeiss AG) with an accelerating voltage of 7 kV and a magnification of 30,000 times to observe the cross-section of the bonding interface between the copper plate and the ceramic substrate in the range of 3 μm in height × 4 μm in width. There was a region where magnesium (Mg) and oxygen (O) coexisted. When the total of magnesium (Mg) and oxygen (O) in this region was set to 100 atomic %, the region where the concentration of magnesium (Mg) was 40 atomic % or more was judged as a magnesium oxide layer, and the area of ​​the region was measured. In addition, the magnesium oxide layer is part of the ceramic component. The thickness of the active metal compound layer is calculated by dividing the measured area by the width of the field of view. The measurements were carried out in five fields of view, and the average values ​​are shown in Tables 4 to 6.

[0165] (Observation of Mg solid solution layer)

[0166] The obtained insulating circuit substrate (copper-ceramic joint body) was collected and observed. The EPMA device (JXA-8530F made by JEOL Ltd.) was used to analyze the cross section of the bonding interface between the copper plate and the ceramic substrate from the interface between the copper part and the active metal compound layer to the direction of the copper part for a length of 200 μm. When the total of active metal, transition metal, Mg, and Cu was set to 100 atomic %, the area with a Mg concentration of more than 0.05 atomic % and less than 6.9 atomic % was judged as the Mg solid solution layer, and the measured length was used as the thickness of the Mg solid solution layer. In addition, the Mg solid solution layer is a part of the copper part. The measurement was carried out in five fields of view, and the average value is shown in Tables 4 to 6.

[0167] (Observation of transition metal layer)

[0168] The obtained insulating circuit substrate (copper-ceramic joint body) was collected and observed by a scanning transmission electron microscope (TitanG2 ChemiSTEM made by Thermo Fisher Scientific Inc.) with an accelerating voltage of 200 kV and a magnification of 640,000 times to observe the cross-section of the bonding interface between the copper plate and the ceramic substrate in a range of 50 nm × 20 nm in height. When the total of Cu, Mg, ceramic constituent elements, active metals and transition metals was set to 100 atomic %, the region with a transition metal concentration higher than 1 atomic % in the active metal compound layer (particles) was judged as a transition metal layer, and the area of ​​the region was measured. The thickness of the transition metal layer was calculated by dividing the measured area by the width of the field of view. The measurements were carried out in five fields of view, and the average values ​​were shown in Tables 4 to 6. Here, ceramic constituent elements refer to Al, Si, N, and O.

[0169] (Surface cutting test)

[0170] The obtained insulating circuit substrate (copper-ceramic joint body) was subjected to a thermal cycle in a liquid bath under the conditions of -40°C×5 min←→150°C×5 min up to 500 cycles.

[0171] A surface cutting test was performed on an insulating circuit substrate (copper-ceramic bonded body) subjected to a thermal cycle to evaluate the bonding strength between the copper plate and the ceramic substrate.

[0172] In the surface cutting test, the copper plate was first cut to a thickness of 30 μm.

[0173] Moreover, if Fig. 7A and Figure 7B As shown, a cutting blade with a blade width of 0.3 mm was used to cut the copper plate at a horizontal cutting speed of 2 μm / sec and a vertical cutting speed of 0.1 μm / sec ((1) cutting stage). When the interface between the copper plate and the ceramic substrate was reached, the cutting blade was moved only in the horizontal direction ((2) stripping stage). The horizontal load at the point when the load in the horizontal direction was constant in the stripping stage was measured. The strength of the bonding interface was calculated by dividing the measured load by the blade width. The evaluation results are shown in Tables 4 to 6.

[0174] [Table 1]

[0175]

[0176] [Table 2]

[0177]

[0178] [Table 3]

[0179]

[0180] [Table 4]

[0181]

[0182] [Table 5]

[0183]

[0184] [Table 6]

[0185]

[0186] Comparing Examples 1 to 8 of the present invention and Comparative Example 1 in which the ceramic substrate is composed of AlN, it was confirmed that Examples 1 to 8 of the present invention in which the transition metal layer was formed had improved strength of the bonding interface compared to Comparative Example 1 in which the transition metal layer was not formed.

[0187] Comparing Examples 11 to 18 of the present invention and Comparative Example 11 in which the ceramic substrate is composed of Si 3 N 4 , it is confirmed that Examples 11 to 18 of the present invention in which the transition metal layer is formed have improved strength of the bonding interface compared to Comparative Example 11 in which the transition metal layer is not formed.

[0188] Comparing Examples 21 to 24 of the present invention and Comparative Example 21 in which the ceramic substrate is composed of Al 2 O 3 , it is confirmed that Examples 21 to 24 of the present invention in which the transition metal layer is formed have improved strength of the bonding interface compared to Comparative Example 21 in which the transition metal layer is not formed.

[0189] The above confirmation test results confirmed that according to the present example, it is possible to provide an insulating circuit substrate (copper-ceramic bonded body) having excellent bonding properties between the ceramic component and the copper component and excellent thermal cycle reliability even when subjected to severe thermal cycles.

[0190] (Example 2)

[0191] First, a ceramic substrate (40 mm×40 mm) was prepared as shown in Table 7. The thickness was 0.635 mm in the case of AlN and Al2O3, and 0.32 mm in the case of Si3N4.

[0192] Furthermore, as a copper plate to be used as a circuit layer and a metal layer, a copper plate of 37 mm×37 mm made of oxygen-free copper and having a thickness of 0.25 mm was prepared.

[0193] Then, each element shown in Table 7 was disposed as a bonding material between the ceramic substrate and the copper plate to obtain a laminate of copper plate-ceramic substrate / copper plate.

[0194] Next, the copper plate and the ceramic substrate were bonded together under the conditions shown in Table 8 to obtain insulating circuit substrates (copper-ceramic bonded bodies) of Inventive Examples A1 to A16 and Comparative Examples A1 to A3.

[0195] The obtained insulating circuit substrate (copper-ceramic bonded body) was subjected to observation of the bonding interface and a surface cutting test.

[0196] In addition, each layer in the bonding interface was observed as follows. The observation results of Example A1 of the present invention are shown in FIG. Figure 8 The observation results of Example A2 of the present invention are shown in Fig. 9 middle.

[0197] (Observation of Active Metal Compound Layer)

[0198] The observation of the active metal compound layer was basically carried out by the same method as in Example 1. In the case of this example, there is a region where the active metal and N or O coexist. In this region, when the total of the active metal, N and O is set to 100 atomic %, the region where the concentration of the active metal is 20 atomic % or more is judged to be the active metal compound layer, and the area of ​​the region is measured. The thickness of the active metal compound layer is calculated by the same method as in Example 1. The measurement was performed in five viewing fields, and the average value is shown in Table 8.

[0199] (Observation of Cu-Ag layer)

[0200] The obtained insulating circuit substrate (copper-ceramic joint body) was collected and observed. The EPMA device (JEOL Ltd. JXA-8530F) was used to analyze the cross section of the joint interface of the copper plate and the ceramic substrate from the interface of the copper part and the active metal compound layer to the direction of the copper part for a length of 100 μm. When the total of active metal, Ag and Cu was set to 100 atomic %, the region where the concentration of Ag was 9 atomic % or more was judged as the Cu-Ag layer, and the measured length was set to the thickness of the Cu-Ag layer. In addition, the Cu-Ag layer is a part of the copper part. Measured in five visual fields, the average value is shown in Table 8.

[0201] In addition, the Cu phase in the Cu-Ag layer is integrated with the Cu of the copper plate and therefore cannot be distinguished in composition.

[0202] (Observation of transition metal layer)

[0203] The observation of the transition metal layer is basically carried out by the same method as in Example 1. In the case of this embodiment, when the total of Cu, Ag, ceramic constituent elements, active metals and transition metals is set to 100 atomic %, the region with a transition metal concentration higher than 1 atomic % in the active metal compound layer (particles) is judged as the transition metal layer, and the area of ​​the region is measured. The thickness of the transition metal layer is calculated by dividing the measured area by the width of the measured field of view. The measurements are performed in five fields of view, and the average values ​​are shown in Table 8. Here, the ceramic constituent elements refer to Al, Si, N, and O.

[0204] The observation results of Example A1 of the present invention are shown in Figure 8 The observation results of Example A2 of the present invention are shown in Fig. 9 middle.

[0205] (Surface cutting test)

[0206] The surface cutting test was performed by the same method as in Example 1. Table 8 shows the evaluation results.

[0207]

[0208] [Table 8]

[0209]

[0210] Comparison of Examples A1 to A7 of the present invention and Comparative Example A1 in which the ceramic substrate is composed of AlN shows that Examples A1 to A7 of the present invention in which the transition metal layer is formed have improved strength of the bonding interface compared to Comparative Example A1 in which the transition metal layer is not formed.

[0211] Comparing Examples A8 to A14 of the present invention and Comparative Example A2 in which the ceramic substrate is composed of Si3N4, it is confirmed that Examples A8 to A14 of the present invention in which the transition metal layer is formed have improved strength of the bonding interface compared to Comparative Example A2 in which the transition metal layer is not formed.

[0212] Comparing the examples A15 and A16 of the present invention and the comparative example A3 in which the ceramic substrate is composed of Al2O3, it is confirmed that the strength of the bonding interface is improved in the examples A15 and A16 of the present invention in which the transition metal layer is formed, compared with the comparative example A3 in which the transition metal layer is not formed.

[0213] Here, in Example A1 of the present invention, Figure 8 As shown, it was observed that an Fe phase (transition metal layer) was formed between the Cu phase and the TiN (active metal compound layer).

[0214] Furthermore, in Example A2 of the present invention, Fig. 9 As shown in FIG. 1 , it is observed that an Fe phase (transition metal layer) is formed between the Ag phase and the TiN (active metal compound layer). Fig. 9 In the embodiment, a Cu phase was confirmed between the Ag phase and the Fe phase (transition metal layer).

[0215] (Example 3)

[0216] Ceramic substrates (40 mm×40 mm) shown in Table 9 were prepared in the same manner as in Example 2. The thickness was 0.635 mm in the case of AlN and Al2O3, and 0.32 mm in the case of Si3N4.

[0217] Furthermore, as a copper plate to be used as a circuit layer and a metal layer, a copper plate of 37 mm×37 mm made of oxygen-free copper and having a thickness of 0.25 mm was prepared.

[0218] Then, each element shown in Table 9 was disposed between the ceramic substrate and the copper plate as a bonding material to obtain a laminate of copper plate-ceramic substrate / copper plate.

[0219] Next, the copper plate and the ceramic substrate were bonded together under the conditions shown in Table 10 to obtain insulating circuit substrates (copper-ceramic bonded bodies) of Inventive Examples A21 to A30 and Comparative Examples A21 to A23.

[0220] The obtained insulating circuit board (copper-ceramic bonded body) was subjected to observation of the bonding interface in the same manner as in Example 2. Table 10 shows the evaluation results.

[0221] The obtained insulating circuit substrate (copper-ceramic joint body) was subjected to a thermal cycle in a liquid bath at -40°C × 5 min←→150°C × 5 min until 1000 cycles. Then, a surface cutting test was performed in the same manner as in Example 2. The evaluation results are shown in Table 10.

[0222]

[0223] [Table 10]

[0224]

[0225] Comparing Inventive Examples A21 to A24 and Comparative Example A21 in which the ceramic substrate is composed of AlN, it is confirmed that Inventive Examples A21 to A24 in which the transition metal layer is formed have improved strength of the bonding interface after thermal cycling loading compared to Comparative Example A21 in which the transition metal layer is not formed.

[0226] Comparing Examples A25 to A28 of the present invention and Comparative Example A22 in which the ceramic substrate is composed of Si3N4, it is confirmed that Examples A25 to A28 of the present invention in which the transition metal layer is formed have improved strength of the bonding interface after hot and cold cycle loading compared to Comparative Example A22 in which the transition metal layer is not formed.

[0227] When comparing Examples A29 and A30 of the present invention and Comparative Example A23 in which the ceramic substrate is composed of Al2O3, it is confirmed that the strength of the bonding interface after hot and cold cycle loading is improved in Examples A29 and A30 of the present invention in which the transition metal layer is formed, compared with Comparative Example A23 in which the transition metal layer is not formed.

[0228] The results of the above confirmation experiments confirmed that according to the present example, an insulating circuit substrate (copper-ceramic bonded body) having excellent bonding properties between the ceramic component and the copper component and excellent thermal cycle reliability can be provided even when subjected to severe thermal cycles.

[0229] Industrial Applicability

[0230] A copper-ceramic bonded body having excellent bonding properties between a ceramic component and a copper component and excellent thermal cycle reliability even when subjected to severe thermal cycles, and an insulating circuit board composed of the copper-ceramic bonded body can be provided.

[0231] Explanation of symbols

[0232] 10, 110 insulation circuit substrate (copper-ceramic joint body)

[0233] 11.111 Ceramic substrate (ceramic components)

[0234] 12, 112 circuit layers (copper parts)

[0235] 13, 113 metal layer (copper parts)

[0236] 31 Active metal compound layer

[0237] 34, 134 Transition metal layer

[0238] 36, 136Mg solid solution layer (or Cu-Ag layer)

[0239] 131 magnesium oxide layer

Claims

1. A copper-ceramic bonded body formed by bonding a copper component made of copper or a copper alloy to a ceramic component, wherein the copper-ceramic bonded body is characterized in that: An active metal compound layer or a magnesium oxide layer is formed in a region of the ceramic component on the copper component side, wherein the active metal compound layer contains a compound of one or more active metals selected from Ti, Zr, Nb and Hf. A transition metal layer containing one or more transition metals selected from V, Cr, Mn, Fe, Co, Ni, Mo, Ta and W is formed at the interface of the active metal compound layer or the magnesium oxide layer on the copper part side.

2. The copper-ceramic joint body according to claim 1, characterized in that: A Mg solid solution layer is formed in a region of the copper component on the ceramic component side. The transition metal layer is formed between the Mg solid solution layer and the active metal compound layer or the magnesium oxide layer.

3. The copper-ceramic joint body according to claim 2, characterized in that: The active metal compound layer is a structure in which a plurality of active metal compound particles are aggregated.

4. The copper-ceramic joint body according to claim 3, characterized in that: A copper grain boundary phase exists between the active metal compound particles.

5. The copper-ceramic joint body according to claim 2, characterized in that: The magnesium oxide layer is a structure in which a plurality of magnesium oxide particles are aggregated.

6. The copper-ceramic joint body according to claim 5, characterized in that: A copper grain boundary phase exists between the magnesium oxide particles.

7. An insulating circuit substrate, which is formed by bonding a copper plate made of copper or a copper alloy to the surface of a ceramic substrate, wherein: An active metal compound layer or a magnesium oxide layer is formed in the region on the copper plate side of the ceramic substrate, wherein the active metal compound layer contains a compound of one or more active metals selected from Ti, Zr, Nb and Hf. A transition metal layer containing one or more transition metals selected from V, Cr, Mn, Fe, Co, Ni, Mo, Ta and W is formed at the interface of the active metal compound layer or the magnesium oxide layer on the copper plate side.

8. The insulating circuit substrate according to claim 7, characterized in that: A Mg solid solution layer is formed in a region of the copper plate on the ceramic substrate side. The transition metal layer is formed between the Mg solid solution layer and the active metal compound layer or the magnesium oxide layer.

9. The insulating circuit substrate according to claim 8, characterized in that: The active metal compound layer is a structure in which a plurality of active metal compound particles are aggregated.

10. The insulating circuit substrate according to claim 9, characterized in that: A copper grain boundary phase exists between the active metal compound particles.

11. The insulating circuit substrate according to claim 8, characterized in that: The magnesium oxide layer is a structure in which a plurality of magnesium oxide particles are aggregated.

12. The insulating circuit substrate according to claim 11, characterized in that: A copper grain boundary phase exists between the magnesium oxide particles.

13. The copper-ceramic joint body according to claim 1, characterized in that: The active metal compound layer and the active metal compound layer in the magnesium oxide layer are formed in a region of the ceramic member on the copper member side.

14. The insulating circuit substrate according to claim 7, characterized in that: The active metal compound layer and the active metal compound layer in the magnesium oxide layer are formed in a region of the ceramic substrate on the copper plate side.

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