Metal-ceramics bonded substrate set, power module, and method for manufacturing power module

Abstract

To provide a metal-ceramics bonded substrate set capable of manufacturing a double-sided cooling type power module using a ceramics substrate as an insulating plate by a simple process, and a power module excellent in heat dissipation property and a method of manufacturing the same.SOLUTION: With a metal-ceramics bonded substrate set, an accommodation space for accommodating a ceramics substrate of a first metal-ceramics bonded substrate and a metal plate and a ceramics substrate of a second metal-ceramics bonded substrate and a metal plate in a state where a base unit of the first metal-ceramics bonded substrate and a base unit of the second metal-ceramics bonded substrate are bonded, and an opening communicating with the accommodation space are formed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a metal / ceramic bonding substrate set, a power module, and a method for manufacturing a power module. [Background technology]

[0002] Inverters, which are key devices in power converters, are equipped with power modules, and in order to increase their efficiency and reduce their size, measures such as reducing loss by switching from Si to SiC power semiconductors and increasing integration are being taken.Increasing the efficiency and reducing the size of power modules requires high power density, and sufficient heat dissipation is required to ensure the long-term reliability of the power modules.

[0003] A typical power module is configured with an insulating substrate, a metal circuit plate bonded to one side of the insulating substrate, and a heat-dissipating metal base plate bonded to the other side, with semiconductor chips and the like mounted on the metal circuit plate. In order to dissipate heat from heat-generating elements such as semiconductor chips to the outside, cooling means such as heat-dissipating fins and a cooling jacket are attached to the heat-dissipating metal base plate.

[0004] Known cooling methods for power modules include a single-sided cooling method in which heat dissipation fins or a cooling jacket are attached to one side of the semiconductor chip to cool it from one side, and a double-sided cooling method in which the semiconductor chip is cooled from both sides. For power modules that generate a large amount of heat due to recent trends toward higher efficiency and smaller size, it is useful to use a double-sided cooling method to improve heat dissipation performance. Patent Document 1, for example, discloses a double-sided cooling power module in which a power semiconductor module is housed in a metal case with heat dissipation sections on both sides. Patent Document 2, for example, discloses a double-sided cooling structure in which thermally conductive grease is placed between an electronic component mounting board and a cooling plate, and the electronic component mounting board is sandwiched between a pair of cooling plates with fins. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-36526 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-38847 Summary of the Invention [Problem to be solved by the invention]

[0006] In the power module disclosed in Patent Document 1, the power semiconductor module is covered with a first sealing resin to cover the outer peripheral side surface while leaving some of the multiple conductor plates constituting the power semiconductor module exposed. The covered power semiconductor module is then housed in a metal case, which is then pressed in the thickness direction and the space within the metal case is sealed with a second sealing resin to manufacture the power module. The technology disclosed in Patent Document 1 thus uses multiple sealing resins to ensure reliable sealing, thereby improving sealing strength and peel resistance. Furthermore, an insulating resin film is used as the insulating member, but the insulating resin film has low voltage resistance, and a structure using a ceramic substrate with better voltage resistance as the insulating member is desired.

[0007] However, with the technology disclosed in Patent Document 1, two sealing processes, namely sealing with a first sealing resin and sealing with a second sealing resin, are required to manufacture a double-sided cooling power module, which raises concerns about the complication of the manufacturing process and an increase in manufacturing costs.

[0008] Furthermore, the technology disclosed in Patent Document 2 above describes a method in which each electronic component mounting board attached to a cooling plate is placed in an electrode-integrated resin case, the collector electrode, emitter electrode, and base electrode are each connected to the electrode-integrated resin case, and each electrode-integrated resin case is filled with sealing resin. To fill the sealing resin, it is necessary to place each electronic component mounting board in the electrode-integrated resin case and fill each electrode-integrated resin case with sealing resin, which is not a simple process.

[0009] In view of the above circumstances, an object of the present invention is to provide a metal-ceramic bonding substrate set that enables a double-sided cooling type power module using a ceramic substrate as an insulating plate to be manufactured through a simple process, and to provide a power module with excellent heat dissipation properties and a manufacturing method thereof. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention provides a metal-ceramic bonding substrate set for use in a double-sided cooling power module, comprising: a first metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one side of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other side of the ceramic substrate; and a second metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one side of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other side of the ceramic substrate, wherein, when the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate are bonded together, a storage space is formed to store the ceramic substrate and metal plate of the first metal-ceramic bonding substrate and the ceramic substrate and metal plate of the second metal-ceramic bonding substrate, and an opening portion is formed in communication with the storage space.

[0011] The base portion of the first metal-ceramic bonding substrate may have a first beam portion integrally formed therewith that extends in the thickness direction of the base portion to form a joint between the base portion of the second metal-ceramic bonding substrate and the first metal-ceramic bonding substrate. The base portion of the second metal-ceramic bonding substrate may have a second beam portion integrally formed therewith that extends in the thickness direction of the base portion to form a joint between the base portion of the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate. The first beam portion and the second beam portion may form a joint such that they partially overlap each other when viewed from the side.

[0012] The base portion may be provided with a plurality of heat dissipation members that extend and protrude in a direction substantially perpendicular to the surface on the side to which the ceramic substrate is not bonded.

[0013] The ceramic substrate may be made of one or more materials selected from alumina, aluminum nitride, silicon nitride, and silicon carbide.

[0014] The base portion and the metal plate may be made of aluminum or an aluminum alloy.

[0015] The first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate may have a base portion directly bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern directly bonded to the other surface of the ceramic substrate.

[0016] Furthermore, according to the present invention, there is provided a double-sided cooling power module, comprising: a first metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a second metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; and a second metal-ceramic bonding substrate having one surface bonded to the metal plate for a circuit pattern of the first metal-ceramic bonding substrate and the other surface a semiconductor chip bonded to a metal plate for a circuit pattern of the second metal-ceramic bonding substrate, wherein a base portion of the first metal-ceramic bonding substrate and a base portion of the second metal-ceramic bonding substrate are bonded to each other, and an accommodating space is formed to accommodate the ceramic substrate and metal plate of the first metal-ceramic bonding substrate, the ceramic substrate and metal plate of the second metal-ceramic bonding substrate, and the semiconductor chip, and an opening portion communicating with the accommodating space is formed, and the accommodating space is filled with a sealing resin.

[0017] The base portion of the first metal-ceramic bonding substrate may have a first beam portion integrally formed therewith that extends in the thickness direction of the base portion to form a joint between the base portion of the second metal-ceramic bonding substrate and the first metal-ceramic bonding substrate. The base portion of the second metal-ceramic bonding substrate may have a second beam portion integrally formed therewith that extends in the thickness direction of the base portion to form a joint between the base portion of the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate. The first beam portion and the second beam portion may form a joint such that they partially overlap each other when viewed from the side.

[0018] The base portion may be provided with a plurality of heat dissipation members that extend and protrude in a direction substantially perpendicular to the surface on the side to which the ceramic substrate is not bonded.

[0019] The ceramic substrate may be made of one or more materials selected from alumina, aluminum nitride, silicon nitride, and silicon carbide.

[0020] The base portion and the metal plate may be made of aluminum or an aluminum alloy.

[0021] The first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate may have a base portion directly bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern directly bonded to the other surface of the ceramic substrate.

[0022] Further, according to the present invention, there is provided a method for manufacturing a double-sided cooled power module, comprising the steps of: mounting a semiconductor chip on a first metal-ceramic bonding substrate comprising a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; and bonding a second metal-ceramic bonding substrate comprising a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate between the base portion of the first metal-ceramic bonding substrate and the a ceramic substrate and a metal plate of the first metal-ceramic bonding substrate, a ceramic substrate and a metal plate of the second metal-ceramic bonding substrate, and a semiconductor chip are bonded to each other in a state where the ceramic substrate and the metal plate of the first metal-ceramic bonding substrate and a base portion of a second metal-ceramic bonding substrate are bonded to each other in a state where the ceramic substrate and the metal plate of the second metal-ceramic bonding substrate and a semiconductor chip are bonded to each other in a state where the semiconductor chip is bonded to the base portion of the first metal-ceramic bonding substrate, and a sealing resin is filled into the storage space through the opening portion.

[0023] The base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate may be joined by laser welding.

[0024] The ceramic substrate may be made of one or more materials selected from alumina, aluminum nitride, silicon nitride, and silicon carbide.

[0025] The base portion and the metal plate may be made of aluminum or an aluminum alloy.

[0026] The first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate may be configured by directly bonding a base portion to one surface of the ceramic substrate and directly bonding a metal plate for a circuit pattern to the other surface of the ceramic substrate. [Effects of the Invention]

[0027] According to the present invention, there is provided a metal-ceramic bonding substrate set that enables a double-sided cooling type power module using a ceramic substrate as an insulating plate to be manufactured through a simple process, and a power module with excellent heat dissipation properties and a manufacturing method thereof can be provided. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a schematic explanatory diagram of a power module. [Figure 2] FIG. 2 is a schematic explanatory view of a first metal / ceramic bonding substrate. [Figure 3] FIG. 2 is a schematic explanatory view of a second metal-ceramic bonding substrate. [Figure 4] 1A to 1C are explanatory diagrams illustrating a method for manufacturing a power module. [Figure 5] 1A to 1C are explanatory diagrams illustrating a method for manufacturing a power module. [Figure 6] 1A to 1C are explanatory diagrams illustrating a method for manufacturing a power module. [Figure 7] 1A to 1C are explanatory diagrams illustrating a method for manufacturing a power module. [Figure 8] 10A and 10B are schematic diagrams showing examples of the shapes of a pair of beam portions that form a joint portion. [Figure 9] FIG. 1 is a schematic view of a first metal / ceramic bonding substrate according to an example. [Figure 10] FIG. 2 is a schematic view of a second metal / ceramic bonding substrate in accordance with an example. DETAILED DESCRIPTION OF THE INVENTION

[0029] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0030] <Power module configuration> Fig. 1 is a schematic explanatory diagram of a double-sided cooling power module 1 according to this embodiment, showing a schematic cross-sectional view of the power module 1 as viewed from the side. As shown in Fig. 1, the power module 1 is formed by bonding together a metal-ceramic bonding substrate set consisting of a first metal-ceramic bonding substrate 30 and a second metal-ceramic bonding substrate 50. The first metal-ceramic bonding substrate 30 and the second metal-ceramic bonding substrate 50 are overlapped with each other so that the surfaces on which the ceramic substrates 33, 53 are disposed face each other, and are bonded together to form an accommodation space P between the two metal-ceramic bonding substrates for accommodating the ceramic substrates 33, 53 and the metal plates 37, 57 for circuit patterns.

[0031] This accommodation space P accommodates the ceramic substrates 33, 53, and also accommodates terminals 71, semiconductor chips 75, and the like at positions sandwiched between the metal plates 37 and 57. The accommodation space P also has an opening 39 on one of the side surfaces (the right end in the figure) of the power module 1 in FIG. 1 that is not the bottom or top surface. As shown in the figure, the terminals 71 may be configured to protrude to the outside through this opening 39. The terminals 71 are used, for example, as signal terminals or input or output electrodes.

[0032] The first metal-ceramic bonding substrate 30 and the second metal-ceramic bonding substrate 50 are bonded together by sealing at least one side of the power module 1 in a plan view. Preferably, three sides of the side surfaces excluding the opening 39 may be sealed. At least one side of the power module 1 opposite the opening 39 (the left end in the figure) is bonded together by sealing a first beam portion 40 and a second beam portion 60 (described later), forming a bonding portion 13. It is preferable that the housing space P is not in communication with the outside of the double-sided cooling type power module 1 by the two base portions, except for one side surface (the opening). This makes it easy to keep the sealing resin within the housing space P when it is injected into the housing space P through the opening. Although it may be possible to keep the sealing resin within the accommodation space P when the sealing resin is poured into the accommodation space P through the opening by sealing only one side of the power module 1 that is positioned opposite the opening 39, it is preferable to seal the three side surfaces excluding the opening in order to more reliably keep the sealing resin within the accommodation space P when the sealing resin is poured into the accommodation space P through the opening. The fact that the two base portions do not communicate with the outside of the double-sided cooling type power module 1 does not prevent the area near the opening that is not filled with sealing resin from being in communication with the outside.

[0033] In this manner, with the terminals 71, semiconductor chips 75, etc. housed in the housing space P, preferably three of the side surfaces excluding the opening 39 are sealed and joined, and sealing resin U is filled in through the opening 39 to seal the interior, thereby forming the power module 1.

[0034] <Configuration of metal-ceramic bonding substrate> (First metal-ceramic bonding substrate) FIG. 2 is a schematic cross-sectional view of a first metal-ceramic bonding substrate 30 according to this embodiment. As shown in FIG. 2, the first metal-ceramic bonding substrate 30 includes an electrically insulating ceramic substrate 33 having a substantially rectangular shape in plan view, a base portion 35 having a substantially rectangular shape in plan view bonded to the entire surface of one side (the bottom side in FIG. 2) of the ceramic substrate 33, and a metal plate 37 for one or more circuit patterns bonded to the other side (the top side in FIG. 2) of the ceramic substrate 33. The ceramic substrate 33 and the base portion 35, or the ceramic substrate 33 and the metal plate 37, may be directly bonded without using any other member. While the bonding can be achieved by known brazing or adhesive, direct bonding offers advantages in terms of bonding strength and productivity. The ceramic substrate 33 can be bonded to the base portion 35 at (part of) the side surface and one side of the ceramic substrate 33. This makes it easier to strengthen the bond between the ceramic substrate 33 and the base portion 35 .

[0035] First beam portions 40 are integrally formed on at least one end (left end in the drawing) of the surface of base portion 35 to which ceramic substrate 33 is bonded (top surface in the drawing), and function as a bonding end portion for bonding and integrating first metal-ceramic bonding substrate 30 and second metal-ceramic bonding substrate 50 when manufacturing the above-described power module 1. These first beam portions 40 are preferably formed on three side surfaces of base portion 35. The shape of first beam portion 40 can be arbitrarily designed, and it is preferable to form bonding portion 13, which is configured as an overlapping portion of two beam portions, by bonding first beam portion 40 to second beam portion 60, which will be described later.

[0036] Furthermore, a plurality of heat dissipation members 35a may be provided on the surface of the base portion 35 on the side to which the ceramic substrate 33 is not bonded (the lower surface in the drawing), extending and protruding in a direction approximately perpendicular to the surface. The heat dissipation members 35a may be configured to be detachable from the base portion 35, or may be formed integrally with the base portion 35. The semiconductor chip 75 and the like mounted on the metal plate 37 are heat-generating elements, and the heat is dissipated via the base portion 35. The base portion 35 may dissipate heat by itself, or, if the heat dissipation members 35a are provided, cooling may be achieved by dissipating heat to the heat dissipation members 35a via the base portion 35. The shape of the heat dissipation members 35a is not particularly limited, and may be, for example, pin-shaped or fin-shaped.

[0037] (Second metal-ceramic bonding substrate) FIG. 3 is a schematic cross-sectional view of a second metal-ceramic bonding substrate 50 according to this embodiment. As shown in FIG. 3, the second metal-ceramic bonding substrate 50 includes an electrically insulating ceramic substrate 53 having a substantially rectangular shape in plan view, a base portion 55 having a substantially rectangular shape in plan view bonded to the entire surface of one side (the bottom side in FIG. 3 ) of the ceramic substrate 53, and a metal plate 57 for one or more circuit patterns bonded to the other side (the top side in FIG. 3 ) of the ceramic substrate 53. The ceramic substrate 53 and the base portion 55, or the ceramic substrate 53 and the metal plate 57, may be directly bonded without using any other member. While the bonding can be achieved by known brazing or adhesive, direct bonding is advantageous in terms of bonding strength and productivity. The ceramic substrate 53 can be bonded to the base portion 55 at (part of) the side surface and one side of the ceramic substrate 53. This makes it easier to strengthen the bond between the ceramic substrate 53 and the base portion 55 .

[0038] At least one edge (right edge in the drawing) of the surface of base portion 55 to which ceramic substrate 53 is bonded (top surface in the drawing) is integrally formed with second beam portions 60, which function as a bonding edge for bonding and integrating first metal-ceramic bonding substrate 30 and second metal-ceramic bonding substrate 50 when manufacturing the above-described power module 1. Second beam portions 60 are preferably formed on three side surfaces of base portion 55. The shape of second beam portions 60 can be arbitrarily designed, and it is preferable that second beam portions 60 be bonded to the above-described first beam portion 40 to form bonding portion 13, which is configured as an overlapping portion of the two beam portions.

[0039] Furthermore, a plurality of heat dissipation members 55a may be provided on the surface of the base portion 55 on the side to which the ceramic substrate 53 is not bonded (the lower surface in the drawing), extending and protruding in a direction approximately perpendicular to the surface. The heat dissipation members 55a may be configured to be detachable from the base portion 55, or may be formed integrally with the base portion 55. The semiconductor chip 75 and the like are heat-generating bodies, and the heat generated therefrom is dissipated via the base portion 55. The base portion 55 may dissipate heat by itself, or, if the heat dissipation members 55a are provided, cooling may be achieved by dissipating heat to the heat dissipation members 55a via the base portion 55. The shape of the heat dissipation members 55a is not particularly limited, and may be, for example, pin-shaped or fin-shaped.

[0040] The first beam portion 40 and the second beam portion 60 may have any configuration. For example, they may be configured so that they partially overlap each other when viewed from the side of the power module 1. As an example, the first beam portion 40 (see FIG. 2) extends in the thickness direction of the base portion 35, has a tapered tip, and is formed in a stepped shape. The second beam portion 60 (see FIG. 3) extends in the thickness direction of the base portion 55, has a tapered tip, and is formed in a stepped shape. The tips of the beam portions may be offset in the thickness direction in a plan view and at least partially overlap each other in a side view. The first steps of the stepped first beam portion 40 and second beam portion 60 may be configured to hold the periphery of the ceramic substrates 33, 53 at the respective base portions 35, 55. The shapes of the first beam portion 40 and the second beam portion 60 may be different so that they can be distinguished from each other, or may be shapes that allow them to be aligned during bonding.

[0041] 8A and 8B are schematic diagrams showing an example of the shape of a pair of beams (first beam 40 and second beam 60) constituting joint 13. As shown in FIG. 8A, joint 13 may be configured such that the tips of beams 40a and 60a extending in the thickness direction of bases 35 and 55 are butted against each other and joined. Alternatively, as shown in FIG. 8B, joint 13 may be configured such that only one of the beams (for example, beam 60b in the figure) is shaped to extend in the thickness direction of the base, and the tip of beam 60b formed on base 55 is joined to flat base 35.

[0042] 8(c), the joint 13 may be configured to overlap and join the tips of beams 40c, 60c extending in the thickness direction of the bases 35, 55 with the tips shifted. Also, as shown in Fig. 8(d), the joint 13 may be configured to join a beam 40d formed as a recess in the base 35 and a beam 60d formed as a protrusion in the base 55 by fitting them together so that the tips overlap.

[0043] When laser welding is used as a sealing means for fixing the two base portions together, it is preferable to use a shape and configuration in which a pair of beam portions overlap in side view, as shown in Figures 8(c) and (d), in order to prevent the laser light from penetrating into the interior (storage space P) and to prevent the laser light from irradiating the terminals 71 and the semiconductor chip 75 and damaging them.

[0044] In the first metal-ceramic bonding substrate 30 and the second metal-ceramic bonding substrate 50 configured as described above with reference to FIGS. 2 and 3 , the ceramic substrates 33 and 53 function to maintain insulation between the metal plates 37 and 57 when multiple metal plates 37 and 57 are used for circuit patterns, and between the metal plates 37 and 57 and the base portions 35 and 55. The ceramic substrates 33 and 53 are preferably made of one or more materials selected from alumina, aluminum nitride, silicon nitride, and silicon carbide. When used as an insulating substrate for a power module, aluminum nitride or silicon nitride is preferred from the viewpoints of reliability and heat dissipation. The ceramic substrates 33 and 53 may contain unavoidable impurities or sintering aids. The thickness of the ceramic substrates 33 and 53 may be 0.1 mm to 1.0 mm, and the overall thickness of the metal-ceramic bonding substrate may be 1.0 mm to 5.0 mm. The shape of the ceramic substrates 33 and 53 is not particularly limited, but they can be approximately rectangular in plan view.

[0045] The base portions 35, 55 are preferably directly bonded to the ceramic substrates 33, 53. While this bonding can be achieved using known brazing or adhesives, direct bonding is advantageous in terms of bonding strength and productivity. The base portions 35, 55 may be formed on the periphery of one surface of the ceramic substrates 33, 53, the side surfaces, and the entire surface of the other surface. While the ceramic substrates 33, 53 can be bonded to the base portions 35, 55 only on one surface of the ceramic substrates 33, 53, bonding the side surfaces and the other surface also strengthens the bond between the ceramic substrates 33, 53 and the base portions 35, 55. The base portions 35, 55 may also be made of aluminum, an aluminum alloy, or copper. Aluminum is preferred from the viewpoints of achieving both hardness and thermal conductivity and suppressing deformation due to stress that may occur in the base portions 35, 55 when directly bonded to the ceramic substrates 33, 53. It is desirable that the base portions 35, 55 have a certain degree of hardness as a constituent member as well as thermal conductivity, and therefore are preferably harder than the metal plates 37, 57 for the circuit patterns.

[0046] The metal plates 37, 57 for the circuit patterns are preferably directly bonded to the ceramic substrates 33, 53. While this bonding can be achieved by known brazing or adhesive bonding, direct bonding is advantageous in terms of bonding strength and productivity. The metal plates 37, 57 may be made of aluminum, an aluminum alloy, or copper. Specifically, since chip components such as the semiconductor chip 75 are mounted on the metal plates 37, 57, a metal with excellent electrical and thermal conductivity is preferred. For example, the metal plates 37, 57 are preferably made of aluminum or an aluminum alloy containing 99.7% by mass or more, more preferably 99.9% by mass or more of aluminum. Note that the metal plates 37, 57 may be made of a high-hardness aluminum alloy to prevent deformation of the base portions 35, 55 and the metal plates 37, 57 due to stress, such as when the sealing resin U is filled and solidified.

[0047] The metal-ceramic bonding substrates 30, 50 may be manufactured by any method, including a general molten metal bonding method such as that described in JP 2017-228551 A. When the molten metal bonding method is used, the tapered shapes of the first beam portion 40 and the second beam portion 60 as described above allow the manufactured substrate to be easily removed from the mold.

[0048] <Power module manufacturing method> Power module 1 according to this embodiment is manufactured by combining a set of first metal-ceramic bonding substrate 30 and second metal-ceramic bonding substrate 50 as described above. An example of a method for manufacturing power module 1 will now be described with reference to the drawings.

[0049] 4 to 7 are explanatory views of the manufacturing method of power module 1 according to this embodiment, in which FIG. 4 shows the process of mounting semiconductor chip 75 and the like on first metal-ceramic bonding substrate 30, and FIGS. 5 to 7 show the process of bonding first metal-ceramic bonding substrate 30 and second metal-ceramic bonding substrate 50.

[0050] First, as shown in FIG. 4( a), in the first metal-ceramic bonding substrate 30, a plating layer 70 and terminals 71 are mounted on a metal plate 37 for forming a circuit pattern. The plating layer 70 and terminals 71 may be arranged in any configuration. The plating layer 70 may be formed as needed. For example, the terminals 71 may be configured to extend toward the openings 39 (see FIG. 1 ) when the power module 1 is manufactured and protrude outward from the openings 39. The plating layer 70 may be formed on the metal plate 37 by any method, such as electrolytic plating or electroless plating. The terminals 71 may be joined to the metal plate 37 by any method, such as metal wire joining.

[0051] 4(b), a first bonding material 73 is provided on the plating layer 70. The first bonding material 73 may be, for example, solder or a sintered material based on an element of Group 11 of the periodic table (sintered Cu, sintered Ag, etc.). Then, as shown in FIG. 4(c), a semiconductor chip 75 is mounted on the first bonding material 73, and one surface (the lower surface in the figure) of the semiconductor chip 75 is bonded to the metal plate 37 for the circuit pattern via the first bonding material 73 and the plating layer 70.

[0052] 4(d), a second bonding material 77 is provided on the other surface (the upper surface in the figure) of the semiconductor chip 75. The second bonding material 77 may be the same as the first bonding material 73, and may be, for example, solder or a sintered material based on an element of Group 11 of the periodic table (sintered Cu, sintered Ag, etc.).

[0053] 5, metal plate 57 of second metal-ceramic bonding substrate 50 is placed so as to be bonded to second bonding material 77, and semiconductor chip 75 is sandwiched between first metal-ceramic bonding substrate 30 and second metal-ceramic bonding substrate 50. As shown in the figure, an accommodation space P is formed between first metal-ceramic bonding substrate 30 and second metal-ceramic bonding substrate 50 to accommodate ceramic substrates 33, 53 and metal plates 37, 57.

[0054] 6, with semiconductor chip 75 sandwiched between them, a step is performed in which sealing means 80 is used to seal the contact area between base portion 35 of first metal-ceramic bonding substrate 30 and base portion 55 of second metal-ceramic bonding substrate 50. The sealing is performed on the side surfaces of base portions 35, 55 excluding openings 39, and at least one surface of base portions 35, 55, which are substantially rectangular in plan view, is sealed and bonded. Preferably, three side surfaces excluding openings 39 may be sealed. The sealing here is a process of bonding and fixing the two base portions together at bonding portion 13.

[0055] As shown in the figure, this sealing process may be performed by joining first beam 40 formed on base 35 and second beam 60 formed on base 55 at welded portion 81. This forms joint 13, which is the overlapping portion of the two beams, and reliably seals storage space P. That is, first metal-ceramic bonding substrate 30 and second metal-ceramic bonding substrate 50 are joined by joint 13 and integrated with semiconductor chip 75 and the like therein, forming storage space P. Specific examples of sealing means 80 will be described later.

[0056] 7, sealing resin U is then filled into housing space P through opening 39 to seal the interior. As a result, semiconductor chip 75 sandwiched between first metal-ceramic bonding substrate 30 and second metal-ceramic bonding substrate 50 is resin-sealed, and power module 1 is manufactured with only terminals 71 protruding from opening 39. This power module 1 is configured as a double-sided cooling system in which semiconductor chip 75 is sandwiched between a pair of metal-ceramic bonding substrates 30, 50 equipped with heat dissipation members on both sides thereof, and is cooled from both sides.

[0057] <Specific examples of sealing methods> Any sealing means may be used for the sealing process carried out in the method for manufacturing the power module 1 described with reference to Figures 4 to 7, and various methods are possible. Specific examples thereof will be described below.

[0058] (laser welding) Laser welding may be used as sealing means 80 for joining base portion 35 and base portion 55. In laser welding, it is preferable to use a laser beam with a high energy absorption rate and a short wavelength in order to achieve deep welding instantaneously in a short time. Specifically, in welding aluminum-based materials, it is preferable to use a semiconductor laser, fiber laser, or YAG laser. From the viewpoints of maintenance costs and high output power required to achieve deep welding, fiber lasers are particularly preferable. Laser welding is preferable as sealing means because it causes little damage to the semiconductor chip 75 and does not require a separate heating process.

[0059] The preferred conditions for using a fiber laser are as follows: The laser output is preferably 200 to 2700 W for a welding thickness of 0.5 mm to 4 mm. The slower the laser scanning speed, the deeper the weld that can be obtained, and the faster the speed, the shorter the production time. From this perspective, the laser scanning speed is preferably 40 mm / s or more and 1000 mm / s or less. The laser irradiation direction may be perpendicular to the side surfaces of the contact portion between base portion 35 and base portion 55, which are the welding targets (i.e., the laser irradiation angle is 90°), or the angle between the laser irradiation direction and the side surfaces of the contact portion between base portion 35 and base portion 55 (laser irradiation angle: taper angle) may be 5° to 90°.

[0060] During laser welding, it is preferable to use an inert gas as a shielding gas or to use a wobble function to prevent oxidation and reduce debris generated during laser welding. Helium or argon is preferably used as the inert gas. The shielding gas flow method may be, for example, a coaxial nozzle or a side nozzle.

[0061] When laser welding is used as the sealing means 80, it is possible to select an appropriate laser light source, a spot diameter below a certain level, laser output, etc. depending on the metal material of the base portions 35 and 55, and it is possible to weld and seal only the target areas in a short time using high-speed scanning. Therefore, there is no risk of damaging the internal semiconductor chip 75, and the sealing process can be carried out efficiently.

[0062] (Friction stir welding) Friction stir welding may be used as sealing means 80 for joining base portion 35 and base portion 55. By using friction stir welding, the sealing process can be performed without generating debris or the like. However, since a load is applied along with the friction vibration, the vibration and load may be transmitted to first metal-ceramic bonding substrate 30 and second metal-ceramic bonding substrate 50, which may damage semiconductor chip 75 inside.

[0063] (brazing method) Brazing may be used as the sealing means 80 for joining the base portion 35 and the base portion 55. In brazing, a filler metal is used to perform the sealing process, so that the sealing process can be easily performed even if the base portion 35 and the base portion 55 are made of different metal materials. On the other hand, brazing requires heat bonding in an atmospheric furnace, and the bonding temperature exceeds 400°C, for example. Therefore, there is a concern that the semiconductor chip 75 may be damaged due to heating, and that it may take a long time to cool down.

[0064] (Sintering method) A sintering method may be used as the sealing means 80 for joining the base portion 35 and the base portion 55. In the sintering method, a sintering material is selected according to the metal material of the base portions 35, 55, and the joining is performed at a low pressure at a temperature that will not damage the semiconductor chip 75. Because the joining is performed at a low pressure, there is almost no risk of the semiconductor chip 75 being damaged. On the other hand, because the joining is performed at a low pressure, the joining layer is likely to become loose, which may result in insufficient sealing.

[0065] <Action and effect> In the set of the first metal-ceramic bonding substrate 30 and the second metal-ceramic bonding substrate 50 according to this embodiment, the base portions 35, 55 and the metal plates 37, 57 may be directly bonded to the ceramic substrates 33, 53. In this case, there is no need to use thermally conductive grease or the like, and excellent voltage resistance is achieved. Furthermore, by manufacturing a power module 1 using a set of the first metal-ceramic bonding substrate 30 and the second metal-ceramic bonding substrate 50, a double-sided cooling power module 1 with excellent durability can be manufactured using a simple process. In other words, by limiting the number of sealing steps with the sealing resin U to one, improved production efficiency and reduced production costs can be achieved compared to the conventional double-sided cooling power module described in Patent Document 1.

[0066] Furthermore, when bonding the first metal-ceramic bonding substrate 30 and the second metal-ceramic bonding substrate 50, beams (first beam 40 and second beam 60) are formed on the base portions 35 and 55, respectively, and bonding is performed by forming a bonding portion 13 where the two beams overlap. This structure ensures a reliable sealing process during bonding, minimizing adverse effects on the semiconductor chip 75 held in the housing space P during bonding. In particular, when laser welding is used as the sealing means 80, this prevents laser light from penetrating into the interior (housing space P), preventing damage to the terminals 71 and the semiconductor chip 75 due to irradiation of the laser light.

[0067] While one embodiment of the present invention has been described above, the present invention is not limited to the illustrated embodiment. It is clear that a person skilled in the art can conceive of various modifications and alterations within the scope of the ideas described in the claims, and it is understood that these also naturally fall within the technical scope of the present invention. [Example]

[0068] <Example> As an example of the present invention, a power module manufactured using laser welding in the manufacturing method described in the above embodiment was subjected to a heat cycle test to evaluate the welding condition. To obtain the test specimens, a first metal-ceramic bonding substrate and a second metal-ceramic bonding substrate were first prepared. Fig. 9 is a schematic diagram of the first metal-ceramic bonding substrate, showing its partial dimensions. Fig. 10 is a schematic diagram of the second metal-ceramic bonding substrate, showing its partial dimensions. In addition to the plan views, Figs. 9 and 10 also show the AA and BB cross sections of the plan views.

[0069] The first metal-ceramic bonding substrate was produced by first placing an aluminum nitride plate serving as a rectangular ceramic substrate, measuring 68 mm in length, 17 mm in width, and 0.635 mm in thickness, into a mold, which was then heated in a nitrogen atmosphere inside the mold. Molten high-purity aluminum containing at least 99.9% by mass of aluminum was then poured into the mold while removing the oxide film on its surface. The mold was then cooled to solidify the molten aluminum, yielding a first metal-ceramic bonding substrate integrated with a metal base plate.

[0070] The resulting first metal-ceramic bonding substrate had an aluminum base portion integrally formed on the periphery of one surface of the ceramic substrate (a 1 mm wide portion covered with aluminum from the periphery), the side surfaces, and the entire other surface. When viewed from the other surface, this base portion was rectangular, measuring 77.25 mm long and 22.625 mm wide. The thickness of the base portion was 2.00 mm. Stepped beams (see Figure 9 for the length, width, and thickness of the beams) were formed on the base portion.

[0071] Two circuit patterns measuring 30.75 mm long, 16 mm wide, and 0.6 mm thick were formed on one side of the ceramic substrate, 1.5 mm away from the peripheral edge of one side of the ceramic substrate. One of the circuit patterns had a step measuring 7 mm long, 7 mm wide, and 0.65 mm thick. On the opposite side of the base, 130 columnar projections (heat dissipation pins) measuring 3 mm high and 1.5 mm in diameter were formed, spaced 2.5 mm apart and extending approximately perpendicular to the surface. This resulted in a metal-ceramic bonding substrate with an integrated metal base plate. The width of the base formed on the side of the ceramic substrate (the distance from the side of the ceramic substrate to the side of the base) was 4.625 mm, and the thickness of the base was 2.00 mm.

[0072] The second metal-ceramic bonding substrate was produced by first placing an aluminum nitride plate as a rectangular ceramic substrate, measuring 68 mm in length, 17 mm in width, and 0.635 mm in thickness, into a mold, which was then heated in a nitrogen atmosphere inside the mold. Molten high-purity aluminum containing at least 99.9% by mass of aluminum was then poured into the mold while removing the oxide film on its surface. The mold was then cooled to solidify the molten aluminum, yielding a second metal-ceramic bonding substrate integrated with a metal base plate.

[0073] The resulting metal-ceramic bonding substrate had an aluminum base formed integrally on the periphery of one surface of the ceramic substrate (a 1 mm wide portion covered with aluminum from the periphery), the side surfaces, and the entire other surface. When viewed from the other surface, this base was rectangular, measuring 77.25 mm long and 22.625 mm wide. The thickness of the base was 2.00 mm. Stepped beams (see Figure 10 for the length, width, and thickness of the beams) were formed on the base.

[0074] Two circuit patterns measuring 30.75 mm long, 13 mm wide, and 0.6 mm thick were formed on one side of the ceramic substrate, 2 mm away from the peripheral edge of one side of the ceramic substrate. One of the circuit patterns had a step measuring 7 mm long, 7 mm wide, and 0.65 mm thick. On the opposite side of the metal base plate, 130 columnar projections (heat dissipation pins) measuring 3 mm high and 1.5 mm in diameter were formed, spaced 2.5 mm apart, extending approximately perpendicular to the surface. This resulted in a metal-ceramic bonding substrate with an integrated metal base plate. The width of the base formed on the side of the ceramic substrate (the distance from the side of the ceramic substrate to the side of the base) was 4.625 mm, and the thickness of the metal base plate was 2.0 mm.

[0075] Next, Al or Cu electrodes or terminals were bonded to the circuit patterns of the first and second metal-ceramic bonding substrates in a direction extending toward the opening, followed by "metal wire bonding of Al, Cu, or other materials to predetermined locations on the circuit portions." Then, solder was applied as a bonding material to predetermined locations on the circuit patterns of the first and second metal-ceramic bonding substrates. A semiconductor chip was mounted on one of the substrates, and the bases of the first and second metal-ceramic bonding substrates were fitted together to bond the chip portions. At this time, the other side of the semiconductor chip was bonded to the circuit pattern of the second metal-ceramic bonding substrate via solder.

[0076] Next, the bonding surfaces (joints) of the bases of the first and second metal-ceramic bonding substrates were laser welded using a fiber laser under the conditions shown in Table 1 below, to integrate the first and second metal-ceramic bonding substrates. The laser was irradiated at a 90° angle and the wobble function was used for the laser welding. In Table 1 below, "3N Al" refers to high-purity aluminum.

[0077] [Table 1]

[0078] Next, sealing resin was filled in through the opening, and the housing space formed when the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate were integrated was sealed with resin, thereby obtaining a power module according to the example.

[0079] To determine whether the laser welding of the bonding surfaces of the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate was performed satisfactorily, a test specimen was prepared as follows using the above power module in the middle of its manufacture, and its durability was examined when it was subjected to a predetermined number of heat cycles under the conditions described below. Specifically, the bonding surfaces (bonding portions) of the base portions of the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate were laser welded using a fiber laser under the conditions listed in Table 1 to prepare a test specimen, which was then subjected to the following heat cycle test. When the cross section of the laser welded portion of this test specimen was observed before and after the heat cycle test, it was found that no cracks or other gaps had occurred in the joint between the base portion of the first metal-ceramic bonded substrate and the base portion of the second metal-ceramic bonded substrate, and that because the accommodation space P is not connected to the outside of the double-sided cooled power module 1 by the two base portions except for one side surface (opening), it is possible to keep the sealing resin within the accommodation space P when it is injected into the accommodation space P through the opening. Furthermore, when the cross section of the laser welded portion of this test specimen was observed before the heat cycle test, no areas were found on the inner surface of the accommodation space where it appeared that the laser had penetrated and melted, confirming that the laser light had not penetrated into the accommodation space.

[0080] The test specimen was placed in a heat cycle test chamber and subjected to 1,000 cycles in an air atmosphere. The heat pattern for one cycle was: → Hold at -40°C for 30 minutes → Hold at 25°C for 10 minutes → Hold at 150°C for 30 minutes → Hold at 25°C for 10 minutes.

[0081] The following configuration examples also fall within the technical scope of the present invention. (1) A metal-ceramic bonded substrate set used in a double-sided cooling power module, a first metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a second metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a metal-ceramic bonding substrate set, characterized in that, when the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate are bonded together, a storage space is formed to store the ceramic substrate and metal plate of the first metal-ceramic bonding substrate and the ceramic substrate and metal plate of the second metal-ceramic bonding substrate, and an opening portion is formed in communication with the storage space. (2) a first beam portion that forms a joint between the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate is integrally formed with the base portion so as to extend in a thickness direction of the base portion; a second beam portion that forms a joint between the base portion of the second metal-ceramic bonding substrate and the base portion of the first metal-ceramic bonding substrate is integrally formed with the base portion so as to extend in a thickness direction of the base portion; The metal-ceramic bonding substrate set according to (1), characterized in that the first beam portion and the second beam portion form a bonding portion such that they partially overlap each other when viewed from the side. (3) The metal-ceramic bonding substrate set according to (1) or (2), characterized in that the base portion is provided with a plurality of heat dissipation members on a surface on the side to which the ceramic substrate is not bonded, the heat dissipation members extending and protruding in a direction approximately perpendicular to the surface. (4) The metal-ceramic bonding substrate set according to any one of (1) to (3), characterized in that the ceramic substrate is made of one or more materials selected from alumina, aluminum nitride, silicon nitride, and silicon carbide. (5) The metal / ceramic bonding substrate set according to any one of (1) to (4), wherein the base portion and the metal plate are made of aluminum or an aluminum alloy. (6) The metal-ceramic bonding substrate set according to any one of (1) to (5), wherein the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate have a base portion directly bonded to one surface of the ceramic substrate and a metal plate for a circuit pattern directly bonded to the other surface of the ceramic substrate. (7) A double-sided cooling type power module, a first metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a second metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a semiconductor chip having one surface bonded to the metal plate for the circuit pattern of the first metal-ceramic bonding substrate and the other surface bonded to the metal plate for the circuit pattern of the second metal-ceramic bonding substrate, a base portion of the first metal-ceramic bonding substrate and a base portion of the second metal-ceramic bonding substrate are bonded together to form a housing space for housing the ceramic substrate and metal plate of the first metal-ceramic bonding substrate, the ceramic substrate and metal plate of the second metal-ceramic bonding substrate, and the semiconductor chip, and an opening communicating with the housing space; A power module, wherein the housing space is filled with a sealing resin. (8) A first beam portion is integrally formed on the base portion of the first metal-ceramic bonding substrate so as to extend in a thickness direction of the base portion, and the first beam portion forms a joint between the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate; a second beam portion that forms a joint between the base portion of the second metal-ceramic bonding substrate and the base portion of the first metal-ceramic bonding substrate is integrally formed with the base portion so as to extend in a thickness direction of the base portion; The power module according to (7), wherein the first beam portion and the second beam portion form a joint portion such that they partially overlap each other when viewed from the side. (9) A power module according to (7) or (8), characterized in that the base portion has a plurality of heat dissipation members provided on the surface on the side to which the ceramic substrate is not bonded, the heat dissipation members extending and protruding in a direction approximately perpendicular to the surface. (10) The power module according to any one of (7) to (9), wherein the ceramic substrate is made of at least one material selected from the group consisting of alumina, aluminum nitride, silicon nitride, and silicon carbide. (11) The power module according to any one of (7) to (10), wherein the base portion and the metal plate are made of aluminum or an aluminum alloy. (12) The power module according to any one of (7) to (11), characterized in that the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate have a base portion directly bonded to one surface of the ceramic substrate and a metal plate for a circuit pattern directly bonded to the other surface of the ceramic substrate. (13) A method for manufacturing a double-sided cooled power module, comprising: a semiconductor chip is mounted on a first metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a second metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate, is arranged in a state in which the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate are bonded to each other, so as to form an accommodation space for accommodating the ceramic substrate and metal plate of the first metal-ceramic bonding substrate, the ceramic substrate and metal plate of the second metal-ceramic bonding substrate, and the semiconductor chip, and an opening portion communicating with the accommodation space; bonding a base portion of the first metal-ceramic bonding substrate to a base portion of the second metal-ceramic bonding substrate; and filling the housing space with a sealing resin through the opening. (14) The method for manufacturing a power module according to (13), wherein the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate are joined by laser welding. (15) The method for producing a power module according to (13) or (14), wherein the ceramic substrate is made of at least one material selected from the group consisting of alumina, aluminum nitride, silicon nitride, and silicon carbide. (16) The method for manufacturing a power module according to any one of (13) to (15), wherein the base portion and the metal plate are made of aluminum or an aluminum alloy. (17) The method for manufacturing a power module according to any one of (13) to (16), characterized in that the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate are formed by directly bonding a base portion to one surface of the ceramic substrate and directly bonding a metal plate for a circuit pattern to the other surface of the ceramic substrate. [Industrial Applicability]

[0082] The present invention is applicable to a metal / ceramic bonding substrate set, a power module, and a method for manufacturing a power module. [Explanation of symbols]

[0083] 1...Power module 13…Joint part 30...First metal-ceramic bonding substrate 33...Ceramic substrate 35...Base 37...Metal plate 39...Opening 40...First beam 50...Second metal-ceramic bonding substrate 53...Ceramic substrate 55...Base 57...Metal plate 60...Second beam 70...Plating layer 71...Terminal 75...Semiconductor chip 80...Sealing means P...Containment space U…Sealing resin

Claims

1. A metal-ceramic bonding substrate set used in a double-sided cooling power module, a first metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a second metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a metal-ceramic bonding substrate set, characterized in that, in a state in which the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate are bonded together, a storage space is formed to store the ceramic substrate and metal plate of the first metal-ceramic bonding substrate and the ceramic substrate and metal plate of the second metal-ceramic bonding substrate, and an opening portion is formed in communication with the storage space.

2. a first beam portion that forms a joint between the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate is integrally formed with the base portion so as to extend in a thickness direction of the base portion; a second beam portion that forms a joint between the base portion of the second metal-ceramic bonding substrate and the base portion of the first metal-ceramic bonding substrate is integrally formed with the base portion so as to extend in a thickness direction of the base portion; 2. The metal-ceramic bonding substrate set according to claim 1, wherein the first beam portion and the second beam portion form a bonding portion such that they partially overlap each other when viewed from the side.

3. 3. The metal-ceramic bonding substrate set according to claim 1, wherein the base portion is provided with a plurality of heat dissipation members on a surface on a side to which the ceramic substrate is not bonded, the heat dissipation members extending and protruding in a direction approximately perpendicular to the surface.

4. 3. The metal / ceramic bonding substrate set according to claim 1, wherein the ceramic substrate is made of at least one material selected from the group consisting of alumina, aluminum nitride, silicon nitride, and silicon carbide.

5. 3. The metal / ceramic bonding substrate set according to claim 1, wherein said base portion and said metal plate are made of aluminum or an aluminum alloy.

6. 3. The metal-ceramic bonding substrate set according to claim 1, wherein the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate have a base portion directly bonded to one surface of the ceramic substrate and a metal plate for a circuit pattern directly bonded to the other surface of the ceramic substrate.

7. A double-sided cooling power module, a first metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a second metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a semiconductor chip having one surface bonded to the metal plate for the circuit pattern of the first metal-ceramic bonding substrate and the other surface bonded to the metal plate for the circuit pattern of the second metal-ceramic bonding substrate, a base portion of the first metal-ceramic bonding substrate and a base portion of the second metal-ceramic bonding substrate are bonded together to form a housing space for housing the ceramic substrate and metal plate of the first metal-ceramic bonding substrate, the ceramic substrate and metal plate of the second metal-ceramic bonding substrate, and the semiconductor chip, and an opening communicating with the housing space; A power module, wherein the housing space is filled with a sealing resin.

8. a first beam portion that forms a joint between the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate is integrally formed with the base portion so as to extend in a thickness direction of the base portion; a second beam portion that forms a joint between the base portion of the second metal-ceramic bonding substrate and the base portion of the first metal-ceramic bonding substrate is integrally formed with the base portion so as to extend in a thickness direction of the base portion; 8. The power module according to claim 7, wherein the first beam portion and the second beam portion form a joint portion such that they partially overlap each other when viewed from the side.

9. 9. The power module according to claim 7, wherein the base portion is provided with a plurality of heat dissipation members on a surface on the side to which the ceramic substrate is not bonded, the heat dissipation members extending and protruding in a direction substantially perpendicular to the surface.

10. 9. The power module according to claim 7, wherein the ceramic substrate is made of at least one material selected from the group consisting of alumina, aluminum nitride, silicon nitride, and silicon carbide.

11. 9. The power module according to claim 7, wherein the base portion and the metal plate are made of aluminum or an aluminum alloy.

12. 9. The power module according to claim 7, wherein the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate have a base portion directly bonded to one surface of the ceramic substrate and a metal plate for a circuit pattern directly bonded to the other surface of the ceramic substrate.

13. A method for manufacturing a double-sided cooled power module, comprising: a semiconductor chip is mounted on a first metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate; a second metal-ceramic bonding substrate including a ceramic substrate, a base portion bonded to one surface of the ceramic substrate, and a metal plate for a circuit pattern bonded to the other surface of the ceramic substrate, is arranged in a state in which the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate are bonded to each other, so as to form an accommodation space for accommodating the ceramic substrate and metal plate of the first metal-ceramic bonding substrate, the ceramic substrate and metal plate of the second metal-ceramic bonding substrate, and the semiconductor chip, and an opening portion communicating with the accommodation space; bonding a base portion of the first metal-ceramic bonding substrate to a base portion of the second metal-ceramic bonding substrate; and filling the housing space with a sealing resin through the opening.

14. 14. The method for manufacturing a power module according to claim 13, wherein the base portion of the first metal-ceramic bonding substrate and the base portion of the second metal-ceramic bonding substrate are joined by laser welding.

15. 15. The method for manufacturing a power module according to claim 13, wherein the ceramic substrate is made of at least one material selected from the group consisting of alumina, aluminum nitride, silicon nitride, and silicon carbide.

16. The method for manufacturing a power module according to claim 13 or 14, wherein the base portion and the metal plate are made of aluminum or an aluminum alloy.

17. 15. The method for manufacturing a power module according to claim 13, wherein the first metal-ceramic bonding substrate and the second metal-ceramic bonding substrate are formed by directly bonding a base portion to one surface of the ceramic substrate and directly bonding a metal plate for a circuit pattern to the other surface of the ceramic substrate.

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