WO2014170997A1 - Power module and manufacturing method therefor - Google Patents

Power module and manufacturing method therefor Download PDF

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Publication number
WO2014170997A1
WO2014170997A1 PCT/JP2013/061562 JP2013061562W WO2014170997A1 WO 2014170997 A1 WO2014170997 A1 WO 2014170997A1 JP 2013061562 W JP2013061562 W JP 2013061562W WO 2014170997 A1 WO2014170997 A1 WO 2014170997A1
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WO
WIPO (PCT)
Prior art keywords
power module
insulating plate
ceramic insulating
intermediate layer
wiring layer
Prior art date
Application number
PCT/JP2013/061562
Other languages
French (fr)
Japanese (ja)
Inventor
英一 井出
谷江　尚史
中津　欣也
Original Assignee
株式会社 日立製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 株式会社 日立製作所 filed Critical 株式会社 日立製作所
Priority to PCT/JP2013/061562 priority Critical patent/WO2014170997A1/en
Priority to JP2015512256A priority patent/JPWO2014170997A1/en
Publication of WO2014170997A1 publication Critical patent/WO2014170997A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
    • H01L23/3735—Laminates or multilayers, e.g. direct bond copper ceramic substrates
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H01L2224/321—Disposition
    • H01L2224/32151—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/32221—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/32225—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/10—Details of semiconductor or other solid state devices to be connected
    • H01L2924/11—Device type
    • H01L2924/13—Discrete devices, e.g. 3 terminal devices
    • H01L2924/1304—Transistor
    • H01L2924/1305—Bipolar Junction Transistor [BJT]
    • H01L2924/13055—Insulated gate bipolar transistor [IGBT]

Definitions

  • the present invention relates to a power module and a manufacturing method thereof.
  • the power semiconductor chip used in this way is required to have a module structure that generates a large amount of heat when energized and can be efficiently cooled, and a module structure that does not break down due to thermal stress generated between the members generated by heat generation. .
  • Patent Document 1 As a conventional technique related to the present invention, for example, there are structures as described in Patent Document 1 and Patent Document 2.
  • the power module described in Patent Document 1 has a thermal expansion higher than that of Cu in order to prevent the ceramic insulating plate from being broken even if the wiring portions and metallized layers provided on both sides of the ceramic insulating plate having a small thermal expansion coefficient are thickened. In this structure, a metal with a small coefficient is inserted.
  • the power module described in Patent Document 2 has a structure in which molten Al is directly bonded to a ceramic insulating plate.
  • the molten Al metal is directly solidified to form a wiring portion for mounting the chip and a base portion for releasing heat.
  • a protrusion for holding the low thermal expansion material is provided on the mold, and the low thermal expansion material is installed at a predetermined position around the chip mounting portion of the wiring portion on which the chip is mounted.
  • the feature of this technology is that a base part that releases heat and a wiring part that mounts a chip with a low thermal expansion material inserted to reduce the thermal stress of the chip are prepared separately, and brazing material with a lower thermal conductivity than that is joined. It is not integrally bonded to the ceramic plate using a material but integrally formed with molten Al.
  • Patent Document 1 in order to reduce the thermal stress of the power module, Mo is combined in order to reduce the thermal expansion of Cu on both sides of the ceramic, but a material having a lower thermal conductivity than Cu is combined. As a result, the heat dissipation efficiency of the power module is reduced.
  • Patent Document 2 in order to hold the insulating substrate and the low thermal expansion material in the mold, it is necessary to take a certain distance between the insulating substrate and the low thermal expansion material in consideration of warpage and thickness variation. There was a problem that the thermal resistance increased by the thickness of the Al layer formed between the two. In addition, since the holding mechanism for installing the low thermal expansion material at a predetermined position on the chip mounting surface of the wiring portion is performed by the protrusion provided on the mold, there is a problem in manufacturing efficiency such as mold production and mold removal after casting. It was.
  • an object of the present invention is to provide a power module structure and a manufacturing method thereof that can improve heat radiation efficiency while reducing thermal stress of the power module using a composite material that has low thermal expansion and high heat dissipation.
  • a power module includes a base portion made of a composite material containing carbon, a ceramic insulating plate mounted on the base portion, and mounted on the ceramic insulating plate, An intermediate layer composed of a composite material, a wiring layer formed in the intermediate layer, and a semiconductor element bonded to the wiring layer via a bonding material, the ceramic insulating plate and the base portion, The ceramic insulating plate and the intermediate layer are joined with a metal forming the wiring layer.
  • FIG. 3A to FIG. 3D show a series of manufacturing methods of the power module 101 which is an example of the present invention.
  • the thickness X of the skin layer 302b formed on the side surface of the intermediate layer 401 of the power module which is a modification of the present invention will be described with reference to (a) and (b), from the thickness X of the skin layer 302b and 125 ° C.
  • produces when it cools to -40 degreeC is shown.
  • FIGS. 6A and 6B are views for explaining the thickness Y of the skin layer 302a formed at the interface between the intermediate layer 401 of the power module 101b and the ceramic insulating plate 501 as a modification of the present invention, and the skin layer 302a.
  • the result (c) of analyzing the relationship between the thickness Y of the skin layer 302a and the maximum thermal stress of the intermediate layer 401 generated when cooled from 125 ° C. to ⁇ 40 ° C. is shown.
  • the cross-sectional schematic diagram of the power module 101b1 which is a modification of this invention is shown.
  • the perspective view (a) and cross-sectional schematic diagram (b) of the power module 102 which are the modifications of this invention are shown.
  • the manufacturing method (a) and (b) of the power module 102 which is a modification of this invention is shown.
  • the perspective view (a) and cross-sectional schematic diagram (b) of the power module 103 which are the modifications of this invention are shown.
  • the manufacturing method (a) and (b) of the power module 103 which is a modification of this invention is shown.
  • the cross-sectional schematic diagram of the power module 104 which is a modification of this invention is shown.
  • the shape of the ceramic insulation board 501 and the base 402 of the power module of this invention, and the distribution map of the thermal stress generated when it cools from 125 degreeC to -40 degreeC are shown.
  • the logarithmic graph which showed the relationship between the shape from the ceramic insulating board 501 and the base 402 of the power module of this invention, the thermal stress generated when it cools from 125 degreeC to -40 degreeC, and the distance from a junction edge part is shown. .
  • the manufacturing method of the power module 104 which is a modification of this invention is shown.
  • FIG. 8A to FIG. 8D show a series of manufacturing methods of the power module 105 which is a modification of the present invention.
  • the cross-sectional schematic diagram of the power module 106 which is a modification of this invention is shown. It is the figure which looked at the composite material 310 of this invention from the upper surface.
  • the cross-sectional schematic diagram of the power module 107 which is a modification of this invention is shown.
  • the cross-sectional schematic diagram of the power module 108 which is a modification of this invention is shown. It is the figure which looked at the carbon molding 451 of this invention from the upper surface.
  • FIG. 1 is a perspective view of an example of a power module according to the present invention
  • FIG. 2 is a cross-sectional view taken along line AA ′ of FIG.
  • the power module 101 includes a base 402 from below, a ceramic insulating plate 501 disposed in contact with the base 402, an intermediate layer 401 disposed in contact with the ceramic insulating plate 501, and an intermediate layer 401.
  • the wiring layer 301 is joined to the wiring layer 301, and the IGBT 201 and the diode 202 are joined to the wiring layer 301 via the metal joint portion 601 in this order.
  • the wiring layer 301 is made of Al, Cu, or an alloy thereof having a small electric resistance, and has a thickness that satisfies the electric capacity required for the module.
  • the intermediate layer 401 under the wiring layer 301 is formed of Al—C or Cu—C, which is a composite material of Al, Cu, and C, which is a metal forming the wiring layer, and Al is interposed between porous C. And a structure impregnated with Cu.
  • the intermediate layer 301 is made of a Cu—C composite material when the wiring layer 301 is Cu, and is made of Al—C when the wiring layer 301 is Al.
  • C has higher thermal conductivity and lower thermal expansion than Al and Cu
  • the heat generated from the chip is efficient because it exists in a larger area than the chip on which the intermediate layer 401 configured as described above is mounted.
  • the thermal expansion coefficient is close to that of the chip or ceramic layer, so that the thermal stress generated in the chip or ceramic can be reduced.
  • the base 402 is formed of a composite material of Al or Cu and C, which is a metal forming the wiring layer, like the intermediate layer 401, and contributes to reduction of thermal stress and improvement of heat dissipation.
  • the base 402 and the intermediate layer 401 members having the same thermal expansion coefficient are arranged above and below the ceramic insulating plate 501, and the amount of strain generated above and below the ceramic insulating plate 501 is reduced. The difference can be reduced. Therefore, it is possible not only to reduce the thermal stress by a simple material, but also to reduce the thermal stress generated in the entire structure of the power module.
  • the ceramic insulating plate 501 is made of alumina, aluminum nitride, or silicon nitride with high heat dissipation, has a thickness that satisfies the withstand voltage required for the module, and has a plate shape. Further, as described above, the IGBT 201 (insulated gate bipolar transistor) and the diode 202 are electrically joined to the wiring layer 301 by the metal joint portion 601 such as solder or sintered metal.
  • the wiring layer 301, the intermediate layer 401, the ceramic insulating plate 501, and the base 402 are integrally manufactured by a manufacturing method to be described later, so that a bonding material (for example, a brazing material) is provided between the respective members. Is not arranged, that is, each member is directly joined without any other member. Therefore, it is possible to provide a power module capable of reducing thermal resistance and improving productivity as compared with a structure in which wiring, an intermediate layer, and a base member are prepared in advance and joined with a brazing material or the like.
  • a bonding material for example, a brazing material
  • the intermediate layer 401 and the base 402 serving as the low thermal expansion layer are provided on both surfaces of the ceramic insulating plate 501, as described above, it is possible to reduce the overall warpage during substrate fabrication and chip bonding. Therefore, when the dotted line BB ′ portion shown in FIG. 2 serving as a heat radiating surface is attached to the cooler via grease, the thickness variation is reduced, so that the low thermal conductive grease thickness is reduced and the increase in thermal resistance can be reduced.
  • FIG. 3 (a) a ceramic insulating plate 501 is inserted between porous carbon molded bodies 401a and 402a molded so as to have low thermal expansion and high heat dissipation after impregnation with molten metal.
  • Each positioning is performed by fixing with the molds 701, 702, 703, and 704.
  • the mold 703 is configured to be thicker than the carbon molded body 401a. In other words, a space 301 a is formed between the mold 704 and the carbon molded body 401. By configuring the mold 703 larger than the carbon molded body 401a as described above, the wiring layer 301 can be manufactured at the same time.
  • the mold is composed of a flat laminate with a simple shape. Therefore, it is possible to apply the release agent without any unevenness by a simple method, and it is possible to manufacture in a lump by arranging a large number in the plane direction or the stacking direction.
  • the carbon molded bodies 401a and 402a are arranged on both sides of the ceramic insulating plate 501, and when the fixing with the molds 701, 702, 703 and 704 is completed, the molten metal is replaced with the carbon molded body 401a. , 402a.
  • This process is shown in FIG.
  • FIG. 3B when impregnated with molten metal such as Al or Cu, or an alloy thereof, the porous carbon molded bodies 401a and 402a are impregnated with the molten metal, and have low thermal expansion and high heat dissipation.
  • An intermediate layer 401 and a base 402 made of -C or Cu-C are formed.
  • molten metal simultaneously flows into the space 301a shown in FIG. 3A, and a wiring layer 301 made of Al or Cu having low electrical resistance is formed.
  • the intermediate layer 401, the base 402 and the ceramic insulating plate 501 are joined together by the molten metal skin layer 302 that has exuded from the porous carbon molded bodies 401 a and 402 a. Since the joint portion made of molten metal is extremely thin, the distance between the intermediate layer 401 and the base 402 and the ceramic insulating plate 501 is reduced, and an increase in heat resistance can be suppressed and heat dissipation can be improved.
  • the impregnation of molten metal is performed by dipping in molten metal or injecting molten metal. Pressurization may be applied so that an unfilled part is not formed during the impregnation. At this time, since the temperature is higher than the melting point of Al or Cu, thermal stress is generated during cooling. In the structure of the present invention, since the low thermal expansion portions are installed on both sides of the ceramic, it is possible to reduce the generation and warpage of thermal stress during cooling as compared with the case of installing only on one side.
  • the composite 110 includes a base 402, a ceramic insulating plate 501, an intermediate layer 401, and a wiring layer 301.
  • FIG. 1 An enlarged view of the end A of the ceramic insulating plate 501 is shown in FIG.
  • the molten metal 401a, 402a is impregnated with the molten metal
  • the intermediate layer 401, the base 402, and the ceramic insulating plate 501 have a surface roughness, so there is a slight gap between them.
  • the skin layer 302 made of molten metal is formed and bonded over the entire surface of the intermediate layer 401 and the ceramic insulating plate 501, and the base 402 and the ceramic insulating plate 501.
  • a skin layer 302 made of molten metal is also formed between the molds 701 to 704 and the intermediate layer 401, the base 402 and the ceramic insulating plate 501.
  • the skin layer 302 is formed of Al, Cu, or an alloy thereof rich in spreadability, the thermal stress concentrated on the end portions of the intermediate layer 401, the base 402, and the ceramic insulating plate 501 can be dispersed and reduced.
  • the intermediate layer 401, the base 402, and the ceramic insulating plate 501 are not broken even by thermal stress generated when Al, Cu, or an alloy thereof melts to a room temperature from a high temperature (600 ° C. or higher).
  • the skin layer 302 (dotted line portion in the figure) formed on the ceramic insulating layer 501 is removed to provide an insulating creepage distance. At this time, etching using acid or alkali, blasting, or the like is used. Since the skin layer 302 is extremely thin, it can be easily removed by these processes. On the other hand, the skin layer 302 formed on the outer peripheral portion of the intermediate layer 401 and the base 402 is left because the thermal stress concentrated on the end portions of the intermediate layer 401 and the base 402 can be dispersed and reduced as described above. Is preferred.
  • the IGBT 201 and the diode 202 on the wiring layer 301 are lower in melting point than Sn or Zn or Bi or lower in melting point than Al or Cu. Bonding is performed with Ag or Cu nanoparticles, silver oxide, or copper oxide that are sintered at a temperature to form a metal bonding portion 601. At this time, plating may be performed as a surface treatment for improving the wettability and sinterability of the solder to increase the bonding strength.
  • the power module 101 is completed by bonding a wire or ribbon by ultrasonic bonding of the external terminal to the IGBT 201 and the surface main electrode or control terminal on the diode 202 side and the wiring layer 301.
  • Al—C or Cu—C which is a composite material having lower thermal expansion and higher thermal conductivity than the wiring layer 301, is provided on both surfaces of the ceramic insulating plate 501, and the composite material is connected to the wiring. Bonded with the metal forming the layer.
  • FIG. 4C shows the result of analyzing the relationship between the thickness X of the skin layer 302 b formed on the side surface of the intermediate layer 401 and the thermal stress generated in the intermediate layer 401. Since the same effect is obtained when the skin layer 302b is provided on the side surface of the base 402, it is omitted here.
  • FIG. 4B is an enlarged view of the dotted line portion shown in FIG. As shown in FIG.
  • FIG. 4B a skin layer 302b having a thickness X is provided on the side surface of the intermediate layer 401.
  • FIG. 4C shows the result of calculating the maximum stress generated in the intermediate layer 401 when cooled from 125 ° C. to ⁇ 40 ° C.
  • the horizontal axis in the figure is the thickness of the skin layer 302b
  • the vertical axis is a standard value where the maximum stress generated in the intermediate layer 401 is 1 when there is no skin layer. From the result of FIG. 4C, it can be seen that the maximum value of the thermal stress generated in the intermediate layer 401 monotonously decreases as the thickness of the skin layer 302b increases. In particular, when the thickness X of the skin layer 302b is 10 ⁇ m or more, the generated thermal stress is rapidly reduced.
  • Al—C and Cu—C are less rigid and inferior in thermal stress than Al and Cu, but the thermal stress generated by providing the skin layer 302b in a local region such as the end of the intermediate layer 401 or the base 402 is remarkably high. It was found that the reliability can be improved. Further, as shown in FIG. 4A, the skin layer 302 is not disposed on the main path of the heat flow radiating heat from the chips 201 and 202 to the base 402, so that the chip is increased even if the thickness of the skin layer 302 is increased. The thermal resistance between 201 and 202 and the base 402 does not increase. Furthermore, the side surfaces of the intermediate layer 401 and the base 402 are located at the furthest distance from the chips 201 and 202 that are the heat generation sources, and do not require the effect of heat spreading. It becomes possible to improve.
  • FIG. 5 shows an example in which the surface roughness of the side surfaces of the intermediate layer 401 and the base 402 is increased.
  • FIG.5 (b) is the figure which expanded the dotted-line part shown in Fig.5 (a).
  • the surface roughness of the intermediate layer 401b1 and the base 402b1 is set so that the thickness of the skin layer 302b can be increased at the ends of the intermediate layer 401b1 and the base 402b1. It is getting bigger.
  • dimples may be formed on the side surfaces of the intermediate layer 401c1 and the base 402c1.
  • FIG. 6C shows the result of analyzing the relationship between the thickness Y of the skin layer 302 a formed between the intermediate layer 401 and the ceramic insulating plate 501 and the thermal stress generated in the intermediate layer 401. Since the same effect is obtained when the skin layer 302a formed between the base 402 and the ceramic insulating plate 501 is provided, the description is omitted here.
  • FIG. 6B is an enlarged view of the dotted line portion shown in FIG. As shown in FIG.
  • FIG. 6C shows the result of calculating the maximum stress generated in the intermediate layer 401 when cooled from 125 ° C. to ⁇ 40 ° C.
  • the horizontal axis represents the thickness of the skin layer 302a
  • the vertical axis represents a standard value where the maximum stress generated in the intermediate layer 401 is 1 when there is no skin layer. From the result of FIG. 6C, it can be seen that the maximum value of the thermal stress generated in the intermediate layer 401 monotonously decreases as the thickness of the skin layer 302 increases. In particular, when the thickness Y of the skin layer 302a is 50 ⁇ m or more, the generated thermal stress is rapidly reduced. Therefore, it can be seen that when the thickness of the skin layer 302a is 50 ⁇ m or more, the generated thermal stress can be further reduced.
  • FIG. 7 shows an example in which the surface roughness of the surface of the intermediate layer 401 and the base 402 facing the ceramic insulating plate 501 is increased.
  • FIG.7 (b) is the figure which expanded the dotted-line part shown in Fig.7 (a).
  • FIG. 6B the surface roughness of the intermediate layer 401d1 and the base 402d1 on the ceramic insulating plate 501 side so that the thickness of the skin layer 302a at the interface between the intermediate layer 401d1 and the base 402d1 and the ceramic insulating plate 501 can be increased.
  • dimples may be formed on the surface of the intermediate layer 401e1 or the base 402e1 on the ceramic insulating plate 501 side.
  • FIG. 8 is a perspective view of a power module 102 which is an example of a modification of the power module 101 according to the present invention, and FIG. 8A and FIG.
  • the stress reduction effect of the intermediate layer 461 and the base 462 by the skin layer 302 formed during casting can be applied to the corners of the intermediate layer 461 and the base 462 where the thermal stress is greatest.
  • the skin layer 302 is thickly formed on the entire corners of the intermediate layer 461 and the base 462 (hereinafter, the skin layer formed near the corners of the intermediate layer 461 and the base 462 is referred to as a metallized layer 303).
  • the structures of the intermediate layer 461 and the base 462 are different from those of the intermediate layer 401 and the base 402 of the power module 101 as shown in FIG. A more detailed structure will be described with reference to FIG.
  • FIG. 9 shows a part of a process for manufacturing the power module 102 shown in FIG.
  • FIG. 9A shows a top view of the shape of the carbon molded body 461a before molding and the inner surface 703 '(broken line portion) of the mold 703 for positioning the ceramic insulating plate 501 and the carbon molded body 461a.
  • FIG. 9B is a top sectional view after casting. A corner portion of the carbon molded body 461a and the inner surface 703 'of the mold form a space, and a metallized layer 303 made of molten metal is formed in that region. Further, as shown in FIG.
  • the entire circumference of the carbon molded body 461a is not reduced, and only the corners are reduced, so that positioning can be performed with the mold 703, so that the ceramic insulating plate 501 and the intermediate layer 461 can be positioned. It is possible to increase the alignment accuracy.
  • the base 462 can also be provided with a metallized layer 303 having a thick skin layer formed on the entire surface at the corners of the base 462 while improving the alignment accuracy in the same manner.
  • the corners of the intermediate layer 401 and the base 402 are located at the furthest distance from the chips 201 and 202 serving as heat generation sources, and the effect of improving heat dissipation by improving the heat spread. Therefore, it is possible to improve the reliability without deteriorating the heat dissipation.
  • the corner portion of the intermediate layer 461 (or the base 462) is missing in an L shape, and the convex portions 461b are left on the four surfaces of the intermediate layer 461 (or the base 462). It is also possible to cut off only the corners.
  • the metallized layer 303 preferably has a structure provided up to the same plane as the convex portion 462b from the viewpoint of stress relaxation.
  • FIG. 11A to 11C show a part of a process for manufacturing the power module 103 shown in FIG. As shown in FIG.
  • the protrusion 473a (broken line portion) on the carbon molded body 472a, it is possible to provide a space for forming the metallized layer 303 between the mold 704. That is, the height of the protrusion becomes the metallized layer 303, and the thickness of the metallized layer 303 with a small warp can be manufactured with good reproducibility.
  • the protrusion is integrated with the carbon molded body 472a, the variation in the planar direction of the metallized layer 303 can be made small.
  • the metallized layer 303 is preferably provided up to the same plane as the projection 473 of the base 472 from the viewpoint of stress relaxation.
  • the power module 103 manufactured in this way can reduce the overall warpage during substrate manufacturing and chip bonding, and the thickness variation is reduced when the heat radiation surface is attached to the cooler via grease. As a result, the grease thickness with low thermal conductivity is reduced, and the increase in thermal resistance can be reduced.
  • FIG. 12 shows a power module 104 according to the second embodiment.
  • the difference between this embodiment and the first embodiment is that the area of the base 402 is wider than the ceramic insulating plate 501.
  • the concave portion 422 includes a bottom surface portion 422a and a side wall surface portion 422b.
  • FIG. 13 shows the result of analyzing the thermal stress in each shape.
  • 13A shows a shape in which a concave portion is provided on the ceramic insulating plate 501 installation surface of the base 402
  • FIG. 13B shows a shape in which no concave portion is provided on the ceramic insulating plate 501 installation surface, and FIG. Shape).
  • the result of calculating the stress generated when cooling from 125 ° C. to ⁇ 40 ° C. is shown, and it can be seen that the maximum value of the generated thermal stress is reduced by providing a recess on the ceramic insulating plate 501 installation surface. .
  • FIG. 14 shows the results displayed in double logarithm to show the stress singularity near the edge. It can be seen that the structure shown in FIG. 13A has the smallest thermal stress and can prevent the base 402 and the ceramic insulating plate 501 from being broken. This is because by providing a recess in the base 402, the ceramic insulating plate 501 and the side wall surface 422b of the recess 422 come into contact with the wall surface, and not only in the stacking direction in which the intermediate layer 401 and the like are stacked, but also in other directions (sidewalls). It is considered that the stress can be released also in the direction in which the surface portion 422b abuts and the stress can be dispersed.
  • a porous carbon molded body 401a and a carbon molded body 402b that is wider than the carbon molded body 401a and has a recess are prepared.
  • the carbon molded body 402b is configured such that both sides are wider than the ceramic insulating plate 501. Further, according to this structure, the thickness of the mold 801 in the horizontal direction is made thinner than the thickness of the mold 703 in the horizontal direction.
  • a concave portion 422 is provided in a portion of the base 402 where the ceramic insulating plate 501 is brought into contact, and the ceramic insulating plate 501 is disposed in the concave portion 422 (that is, brought into contact with the side wall surface portion 422b of the concave portion 422). The stress can be reduced.
  • the power module according to this embodiment is greatly different from the first embodiment in its manufacturing method. A modification of the power module manufacturing method according to the present invention will be described with reference to FIG.
  • FIG. 16 (a) shows a state before the molten metal is added.
  • Fig.16 (a) it is set as the structure which provides the protrusion part 401b in a part of peripheral part of the porous carbon molding 401a.
  • a mold for forming the wiring layer 301 can be omitted. Therefore, a mold 901 in which the molds 701, 702, and 703 are integrated as in the first embodiment can be used. Further, since the mold 901 can have a simple structure as described above, a plurality of composite materials 210 can be manufactured at once, and productivity is improved.
  • molten metal is poured into the carbon molded bodies 401a and 401b and carbon molded body 402a, respectively, and an intermediate layer 411 having a concave portion surrounded by the convex portion 411b, and a base 402 is formed.
  • the wiring layer 301 is formed in the concave portion surrounded by the convex portion 411b.
  • the ends of the intermediate layer 411 are shaved using means such as polishing and excavating both ends to obtain the power module 105.
  • a power module is produced using the carbon molded object which provided the protrusion 401b in the peripheral part of the carbon molded object 401a.
  • the mold can be simplified and the restraint in the thickness direction of the carbon molded body 401a is increased. Therefore, the intermediate layer 401, the base 402, and the skin layer 302 of the ceramic insulating plate 501. It becomes possible to reduce the thickness of the. Therefore, it is possible to reduce the distance between the ceramic insulating plate 501 and the intermediate layer 411, and the distance between the ceramic layer 501 and the base 402, and heat dissipation is further improved. Another advantage is that productivity can be improved because it can be fixed with a small number of molds.
  • the structure of the power module according to this embodiment will be described with reference to FIG.
  • This embodiment is different from the power module of the first embodiment in the structure of the intermediate layer 421 that exists on the upper side of the ceramic 501, and the intermediate layer 421 has a structure in which a protruding portion 421 b that protrudes from the base portion 421 a exists. It is a point.
  • the protruding portion 421b has a higher electrical resistance than the wiring layer 301, and thus it is preferable to provide the protruding portion 421b at a location other than a portion where low electrical resistance is required, such as a chip mounting portion.
  • the protrusion 421b is provided slightly inside (on the side closer to the chip) than the end of the intermediate layer 401, so that a space can be formed outside thereof, and the metallized layer 303 can be provided during casting.
  • the stress of the intermediate layer 401 can be reduced.
  • FIG. 18 is a view seen from above with the intermediate layer 401 of the composite material 310 of this embodiment deleted.
  • the present embodiment by forming a space 432b in the carbon molded body 432a, a portion formed only by the molten metal portion in the base 402 was produced. This point is different from the first embodiment.
  • the end of the ceramic insulating plate 501 where the thermal stress generated in the base 402 concentrates is good, and the corner is more effective for the part to be manufactured.
  • FIG. 19 shows a cross-sectional view of the power module 105 according to the present embodiment. Moreover, the enlarged view of the A section of the power module 105 is shown in FIG.
  • Application of Al—C or Cu—C reduces the amount of generated thermal stress, but Al—C and Cu—C are less rigid and less resistant to thermal stress than Al and Cu. Therefore, as shown in FIG. 19, by forming a power module by providing a space 432 b in the carbon composite 432, it is possible to form a metallized layer 303 in which a local region such as a stress concentration portion is replaced with Al or Cu. It becomes. Therefore, it becomes possible to prevent the destruction of Al—C and Cu—C, and it is possible to provide the power module 107 with improved reliability. Further, as shown in FIG. 19, the effect is further enhanced by tapering the corners of the metallized layer 303.
  • FIG. 21 (a) shows a carbon molded body 451 according to this embodiment
  • FIG. 21 (b) is a diagram of the carbon molded body 451 viewed from the AA cross section of FIG. 21 (a). It is.
  • the point which formed the space 452 of the reverse taper in the carbon molding 451 differs from 1st embodiment.
  • An intermediate layer 461 shown in FIG. 20 can be formed by impregnating the carbon molding 451 with molten metal. Then, at the same time when the intermediate layer 461 is formed, a reverse tapered metal portion 304 formed by solidifying the molten metal is formed. Since it is easy to make a reverse-tapered hole in the carbon molded body 451 before impregnation, the productivity is excellent. In the space, the corner portion of the intermediate layer 461 where the stress is concentrated is effective, and an increase in thermal resistance can be reduced by providing the corner portion away from the chip mounting portion.
  • the inversely tapered metallized layer 304 can be formed after forming the inversely tapered space 452 in the carbon molded body 451 and impregnating the carbon molded body 451 with molten metal. Therefore, the wiring layer 301 and the reverse taper type metallized layer 304 can be integrated, and the power module 105 in which the bonding strength between the wiring 301 and the intermediate layer 461 is improved by the anchor effect can be provided.
  • a power module includes a base portion made of a composite material containing carbon, a ceramic insulating plate mounted on the base portion, and an intermediate portion made of the composite material mounted on the ceramic insulating plate.
  • the intermediate layers are joined with the metal forming the wiring layer. Therefore, the thermal resistance from the wiring layer to the base is reduced, and a power module with high heat dissipation can be provided.
  • the composite material having the same composition is disposed on both surfaces of the ceramic insulating plate 501, whereby the thermal expansion coefficients can be made uniform on both surfaces of the ceramic insulating plate 501, leading to suppression of warpage.
  • the volume of the skin layer made of Al or Cu formed during casting is increased by increasing the unevenness of the side surface of the intermediate layer or the base portion. Therefore, it is possible to reduce the stress generation amount concentrated on the end of Al—C or Cu—C. Therefore, it is possible to prevent the intermediate layer and the base portion from being broken, and it is possible to provide a power module with improved reliability.
  • the power module according to the present invention has a skin layer volume composed of Al or Cu formed during casting by increasing the unevenness of the surface of the intermediate layer or the base portion on the mounting surface side of the ceramic insulating plate. Has increased. Therefore, it is possible to reduce the amount of stress that is concentrated at the end interface between Al—C or Cu—C and the ceramic insulating plate. Therefore, it is possible to prevent the destruction of Al—C and Cu—C, and it is possible to provide a power module with improved reliability.
  • the power module according to the present invention can form a stress relaxation portion replaced with Al or Cu over the entire region of the local region such as the stress concentration portion of the intermediate layer or the base portion. Therefore, it is possible to prevent the intermediate layer and the base portion formed of Al—C or Cu—C from being broken, and it is possible to provide a power module with improved reliability.
  • a protrusion is provided on the bottom surface of the base, and the remaining part is the wiring layer, so that the structure is substantially symmetric with respect to the ceramic insulating plate. Therefore, the amount of deformation such as warpage due to thermal stress can be reduced, and the occurrence of variations in the height of the heat radiation surface can be prevented. Therefore, since the increase in the thickness of the grease having low thermal conductivity due to the variation in the height of the heat radiation surface can be prevented in cooling through the grease, it is possible to provide a power module with further improved heat dissipation.
  • the base portion is configured to be larger than the ceramic insulating plate, the concave portion is provided in the base portion, and the ceramic insulating plate is mounted in the concave portion. Therefore, the ceramic insulating plate can be brought into contact with the side wall surface portion 422b of the recess 422, and thermal stress can be further reduced.
  • the intermediate layer has a recess, and a wiring layer is formed in the recess. Therefore, the combined thermal expansion coefficient between the wiring and the intermediate portion is reduced by the volume of the protruding portion of the intermediate layer, so that the generated thermal stress can be reduced.
  • the base portion has a hole at a position facing the corner of the ceramic insulating plate of the base portion, and the hole is filled with a metal forming the wiring layer.
  • a stress concentration reduction portion replaced with Al or Cu in a local region such as a stress concentration portion. Therefore, it is possible to prevent the destruction of Al—C and Cu—C, and it is possible to provide a power module with improved reliability.
  • a reverse taper portion is configured such that the intermediate layer decreases in size from the wiring layer toward the ceramic insulation plate, and the reverse taper portion, the ceramic insulation plate, In between, the metal which forms the said wiring layer is filled, and a reverse taper metal part is comprised, and the said reverse taper metal part and the said wiring layer are integrally formed. Therefore, it is possible to provide a power module in which the wiring layer and the reverse tapered metal portion can be integrated, and the bonding strength between the wiring and the intermediate layer is improved by the anchor effect.
  • the wiring layer is made of aluminum or copper
  • the composite material is a composite material of metal and carbon constituting the wiring layer. Therefore, since a composite material of Al—C and Cu—C, which has lower thermal expansion and higher heat dissipation than Al and Cu, is used, a highly reliable power module can be provided.
  • a first step of placing a carbon molded body in the mold on both surfaces of the ceramic insulating plate, and molten aluminum or molten copper are poured into the mold. It has a 3rd process which removes a metal mold
  • the carbon molded body disposed on one surface of the ceramic insulating plate has a concave portion, and the ceramic insulating plate is disposed in the concave portion in the first step.
  • the carbon molded body disposed on one surface of the ceramic insulating plate has a concave portion, and the concave portion of the carbon molded body is formed in the first step.
  • the ceramic insulating plate is disposed on a surface opposite to the surface.
  • a hole is provided in the carbon molded body disposed on one surface of the ceramic insulating plate, and in the first step, the hole in the carbon molded body and the ceramic are formed. It arrange
  • the carbon molded body disposed on one surface of the ceramic insulating plate is opposite in that the other surface facing the one surface is smaller than the one surface.
  • the other surface of the carbon molded body is arranged to face the ceramic insulating plate.
  • the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed.
  • the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described.
  • a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment.

Abstract

The purpose of the present invention is to provide the following: a power-module structure that uses a low-thermal-expansion, highly heat-dissipating composite material and can improve heat-dissipation efficiency while reducing the thermal stress applied to a power module; and a method for manufacturing said power-module structure. This power module is provided with the following: a base comprising a carbon-containing composite material; an insulating ceramic plate mounted on said base; an intermediate layer that comprises the aforementioned composite material and is mounted on the insulating ceramic plate; a wiring layer formed on the intermediate layer; and a semiconductor element joined to the wiring layer with a joining material interposed therebetween. The insulating ceramic plate and the base are joined together by a metal that also forms the wiring layer, as are the insulating ceramic plate and the intermediate layer.

Description

パワーモジュール及びその製造方法Power module and manufacturing method thereof
　本発明は、パワーモジュール及びその製造方法に関する。 The present invention relates to a power module and a manufacturing method thereof.
　近年、省エネのためにパワー半導体チップと呼ばれる半導体素子のスイッチングを利用した高効率な小型の電力変換装置が利用されている。このように用いられるパワー半導体チップは通電による大幅に発熱量が高く、効率的に冷却できるモジュール構造、発熱により発生する各部材間に発生する熱応力で破壊しないようなモジュール構造が求められている。 In recent years, high-efficiency small power converters using switching of semiconductor elements called power semiconductor chips have been used for energy saving. The power semiconductor chip used in this way is required to have a module structure that generates a large amount of heat when energized and can be efficiently cooled, and a module structure that does not break down due to thermal stress generated between the members generated by heat generation. .
　本発明にかかわる従来技術としては、例えば、特許文献１や特許文献２に記載されているような構造がある。 As a conventional technique related to the present invention, for example, there are structures as described in Patent Document 1 and Patent Document 2.
　特許文献１に記載されたパワーモジュールは、熱膨張係数が小さいセラミックス絶縁板の両側に設けられる配線部やメタライズ層を厚くしてもセラミックス絶縁板が破壊しないようにするため、Ｃｕよりも熱膨張係数が小さい金属を挿入する構造である。 The power module described in Patent Document 1 has a thermal expansion higher than that of Cu in order to prevent the ceramic insulating plate from being broken even if the wiring portions and metallized layers provided on both sides of the ceramic insulating plate having a small thermal expansion coefficient are thickened. In this structure, a metal with a small coefficient is inserted.
　一方、特許文献２に記載されたパワーモジュールは、溶湯Ａｌがセラミックス絶縁板に直接接合した構造をしている。金型内にセラミックス板を設置することで、溶融したＡｌ金属が直接凝固してチップを搭載する配線部や熱を逃がすベース部を形成している。また、金型に低熱膨張材を保持する突起を設け、チップを搭載する配線部のチップ搭載部周辺の所定の位置に低熱膨張材を設置している。この技術の特徴は、熱を逃がすベース部やチップの熱応力を低減する低熱膨張材を挿入したチップを搭載する配線部を別途用意して、それらよりも熱伝導率の低いろう材等の接合材を用いてセラミックス板に接合するのではなく、溶湯Ａｌにより一体形成したことにある。 On the other hand, the power module described in Patent Document 2 has a structure in which molten Al is directly bonded to a ceramic insulating plate. By installing a ceramic plate in the mold, the molten Al metal is directly solidified to form a wiring portion for mounting the chip and a base portion for releasing heat. Further, a protrusion for holding the low thermal expansion material is provided on the mold, and the low thermal expansion material is installed at a predetermined position around the chip mounting portion of the wiring portion on which the chip is mounted. The feature of this technology is that a base part that releases heat and a wiring part that mounts a chip with a low thermal expansion material inserted to reduce the thermal stress of the chip are prepared separately, and brazing material with a lower thermal conductivity than that is joined. It is not integrally bonded to the ceramic plate using a material but integrally formed with molten Al.
　近年、配線材料に主として用いられるＣｕあるいはＡｌと黒鉛（以下：Ｃ）を複合化することでＣｕやＡｌの低熱膨張化をしつつ、高熱伝導化できる材料（以下：Ｃｕ－Ｃ、Ａｌ－Ｃ複合材料）が開発されている。 In recent years, by combining Cu or Al, which is mainly used for wiring materials, and graphite (hereinafter referred to as C), a material capable of achieving high thermal conductivity while reducing the thermal expansion of Cu or Al (hereinafter referred to as Cu—C, Al—C). Composite materials) have been developed.
特開平０２－１７１５７号公報Japanese Patent Laid-Open No. 02-17157 特開２００６－２９４８９０号公報JP 2006-294890 A
　上述した特許文献１の構造では、パワーモジュールの熱応力低減のため、セラミックスの両面のＣｕを低熱膨張化させるためにＭｏを複合化させているが、Ｃｕよりも熱伝導率の低い材料を複合化したため、パワーモジュールの放熱効率が低下する問題があった。 In the structure of Patent Document 1 described above, in order to reduce the thermal stress of the power module, Mo is combined in order to reduce the thermal expansion of Cu on both sides of the ceramic, but a material having a lower thermal conductivity than Cu is combined. As a result, the heat dissipation efficiency of the power module is reduced.
　一方、特許文献２の構造では、金型で絶縁基板と低熱膨張材を保持するために、反りや厚さばらつきを考慮し、両者の距離を一定量とる必要があり、絶縁基板と低熱膨張材の間に形成されるＡｌ層の厚さ分、熱抵抗が増加する課題があった。また、配線部のチップ搭載面の所定の位置に低熱膨張材を設置するための保持機構を金型に設けられた突起で行うため、型作製や鋳造後の型外しなど製造効率に課題があった。 On the other hand, in the structure of Patent Document 2, in order to hold the insulating substrate and the low thermal expansion material in the mold, it is necessary to take a certain distance between the insulating substrate and the low thermal expansion material in consideration of warpage and thickness variation. There was a problem that the thermal resistance increased by the thickness of the Al layer formed between the two. In addition, since the holding mechanism for installing the low thermal expansion material at a predetermined position on the chip mounting surface of the wiring portion is performed by the protrusion provided on the mold, there is a problem in manufacturing efficiency such as mold production and mold removal after casting. It was.
　本発明は上記課題に鑑み、低熱膨張で高放熱な複合材料を用いて、パワーモジュールの熱応力低減しつつ放熱効率を向上できるパワーモジュール構造とその製造方法の提供することにある。 In view of the above problems, an object of the present invention is to provide a power module structure and a manufacturing method thereof that can improve heat radiation efficiency while reducing thermal stress of the power module using a composite material that has low thermal expansion and high heat dissipation.
　上記課題を解決するために本発明に係るパワーモジュールは、炭素を含有する複合材料により構成されるベース部と、当該ベース部に搭載されるセラミックス絶縁板と、当該セラミックス絶縁板に搭載され、前記複合材料で構成される中間層と、当該中間層に形成される配線層と、当該配線層に接合材料を介して接合される半導体素子と、を有し、前記セラミックス絶縁板と前記ベース部、及び前記セラミックス絶縁板と前記中間層は、それぞれ前記配線層を形成する金属で接合される。 In order to solve the above problems, a power module according to the present invention includes a base portion made of a composite material containing carbon, a ceramic insulating plate mounted on the base portion, and mounted on the ceramic insulating plate, An intermediate layer composed of a composite material, a wiring layer formed in the intermediate layer, and a semiconductor element bonded to the wiring layer via a bonding material, the ceramic insulating plate and the base portion, The ceramic insulating plate and the intermediate layer are joined with a metal forming the wiring layer.
　パワーモジュールに用いられるパワー半導体素子の放熱効率向上、熱応力低減、組立性向上を可能とするパワーモジュールの構造と製造方法の提供できる。 It is possible to provide a power module structure and manufacturing method that can improve the heat radiation efficiency, reduce the thermal stress, and improve the assembly of the power semiconductor element used in the power module.
本発明の一例であるパワーモジュール１０１の斜視図を示す。The perspective view of the power module 101 which is an example of this invention is shown. 本発明の一例であるパワーモジュール１０１の断面模式図を示す。The cross-sectional schematic diagram of the power module 101 which is an example of this invention is shown. 本発明の一例であるパワーモジュール１０１の一連の製造方法を示す図３（ａ）～（ｄ）である。FIG. 3A to FIG. 3D show a series of manufacturing methods of the power module 101 which is an example of the present invention. 本発明の変形例であるパワーモジュールの中間層４０１の側面に形成させたスキン層３０２ｂの厚さＸを説明する（ａ）および（ｂ）と、当該スキン層３０２ｂの厚さＸと１２５℃から-４０℃まで冷却した際に発生する中間層４０１の最大熱応力の関係を解析した結果（ｃ）を示す。The thickness X of the skin layer 302b formed on the side surface of the intermediate layer 401 of the power module which is a modification of the present invention will be described with reference to (a) and (b), from the thickness X of the skin layer 302b and 125 ° C. The result (c) which analyzed the relationship of the maximum thermal stress of the intermediate | middle layer 401 which generate | occur | produces when it cools to -40 degreeC is shown. 本発明の変形例であるパワーモジュール１０１ａ１の断面模式図（ａ）～（ｃ）を示す。Cross-sectional schematic diagrams (a) to (c) of a power module 101a1, which is a modification of the present invention, are shown. 本発明の変形例であるパワーモジュール１０１ｂの中間層４０１とセラミックス絶縁板５０１の界面に形成させたスキン層３０２ａの厚さＹを説明する図（ａ）および（ｂ）と、当該スキン層３０２ａのスキン層３０２ａの厚さＹと１２５℃から-４０℃に冷却した際に発生する中間層４０１の最大熱応力の関係を解析した結果（ｃ）を示す。FIGS. 6A and 6B are views for explaining the thickness Y of the skin layer 302a formed at the interface between the intermediate layer 401 of the power module 101b and the ceramic insulating plate 501 as a modification of the present invention, and the skin layer 302a. The result (c) of analyzing the relationship between the thickness Y of the skin layer 302a and the maximum thermal stress of the intermediate layer 401 generated when cooled from 125 ° C. to −40 ° C. is shown. 本発明の変形例であるパワーモジュール１０１ｂ１の断面模式図を示す。The cross-sectional schematic diagram of the power module 101b1 which is a modification of this invention is shown. 本発明の変形例であるパワーモジュール１０２の斜視図（ａ）と断面模式図（ｂ）を示す。The perspective view (a) and cross-sectional schematic diagram (b) of the power module 102 which are the modifications of this invention are shown. 本発明の変形例であるパワーモジュール１０２の製造方法（ａ）および（ｂ）を示す。The manufacturing method (a) and (b) of the power module 102 which is a modification of this invention is shown. 本発明の変形例であるパワーモジュール１０３の斜視図（ａ）と断面模式図（ｂ）を示す。The perspective view (a) and cross-sectional schematic diagram (b) of the power module 103 which are the modifications of this invention are shown. 本発明の変形例であるパワーモジュール１０３の製造方法（ａ）および（ｂ）を示す。The manufacturing method (a) and (b) of the power module 103 which is a modification of this invention is shown. 本発明の変形例であるパワーモジュール１０４の断面模式図を示す。The cross-sectional schematic diagram of the power module 104 which is a modification of this invention is shown. 本発明のパワーモジュールのセラミックス絶縁板５０１とベース４０２の形状と１２５℃から-４０℃に冷却した際に発生する熱応力の分布図を示す。The shape of the ceramic insulation board 501 and the base 402 of the power module of this invention, and the distribution map of the thermal stress generated when it cools from 125 degreeC to -40 degreeC are shown. 本発明のパワーモジュールのセラミックス絶縁板５０１とベース４０２の形状と１２５℃から-４０℃に冷却した際に発生する熱応力と接合部端部からの距離との関係を示した両対数グラフを示す。The logarithmic graph which showed the relationship between the shape from the ceramic insulating board 501 and the base 402 of the power module of this invention, the thermal stress generated when it cools from 125 degreeC to -40 degreeC, and the distance from a junction edge part is shown. . 本発明の変形例であるパワーモジュール１０４の製造方法を示す。The manufacturing method of the power module 104 which is a modification of this invention is shown. 本発明の変形例であるパワーモジュール１０５の一連の製造方法を示す図８（ａ）～（ｄ）である。FIG. 8A to FIG. 8D show a series of manufacturing methods of the power module 105 which is a modification of the present invention. 本発明の変形例であるパワーモジュール１０６の断面模式図を示す。The cross-sectional schematic diagram of the power module 106 which is a modification of this invention is shown. 本発明の複合材３１０を上面から見た図である。It is the figure which looked at the composite material 310 of this invention from the upper surface. 本発明の変形例であるパワーモジュール１０７の断面模式図を示す。The cross-sectional schematic diagram of the power module 107 which is a modification of this invention is shown. 本発明の変形例であるパワーモジュール１０８の断面模式図を示す。The cross-sectional schematic diagram of the power module 108 which is a modification of this invention is shown. 本発明の炭素成型体４５１を上面から見た図である。It is the figure which looked at the carbon molding 451 of this invention from the upper surface.
《第一の実施形態》
　本発明に関するパワーモジュールの一例の斜視図を図１、図１のＡＡ’断面を図２にそれぞれ示す。 First embodiment
FIG. 1 is a perspective view of an example of a power module according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA ′ of FIG.
　本発明にかかるパワーモジュール１０１は、図２に示す通り、下からベース４０２、ベース４０２に接して配置されるセラミックス絶縁板５０１、セラミックス絶縁板５０１に接して配置される中間層４０１、中間層４０１と接合される配線層３０１、配線層３０１に金属接合部６０１を介して接合されるＩＧＢＴ２０１及びダイオード２０２という順で構成されている。 As shown in FIG. 2, the power module 101 according to the present invention includes a base 402 from below, a ceramic insulating plate 501 disposed in contact with the base 402, an intermediate layer 401 disposed in contact with the ceramic insulating plate 501, and an intermediate layer 401. The wiring layer 301 is joined to the wiring layer 301, and the IGBT 201 and the diode 202 are joined to the wiring layer 301 via the metal joint portion 601 in this order.
　配線層３０１は電気抵抗の小さいＡｌ、Ｃｕあるいはそれらの合金であり、モジュールに求められる電気容量を満足する厚さとなっている。また、配線層３０１下の中間層４０１は、配線層を形成する金属であるＡｌやＣｕとＣとの複合材料であるＡｌ－ＣやＣｕ－Ｃで形成され、多孔質なＣの間にＡｌやＣｕが含浸した構造となっている。この中間層３０１は、配線層３０１がＣｕの場合にはＣｕ－Ｃの複合材料が用いられ、配線層３０１がＡｌの場合にはＡｌ－Ｃで構成される。ＣがＡｌやＣｕよりも、熱伝導率が高く低熱膨張であるため、上記のように構成された中間層４０１が搭載するチップよりも広い面積で存在することで、チップから発生した熱が効率よく集められるとともに、中間層４０１を厚く形成しても熱膨張係数がチップやセラミックス層と近いため、チップやセラミックスに発生する熱応力が低減することが可能となる。 The wiring layer 301 is made of Al, Cu, or an alloy thereof having a small electric resistance, and has a thickness that satisfies the electric capacity required for the module. The intermediate layer 401 under the wiring layer 301 is formed of Al—C or Cu—C, which is a composite material of Al, Cu, and C, which is a metal forming the wiring layer, and Al is interposed between porous C. And a structure impregnated with Cu. The intermediate layer 301 is made of a Cu—C composite material when the wiring layer 301 is Cu, and is made of Al—C when the wiring layer 301 is Al. Since C has higher thermal conductivity and lower thermal expansion than Al and Cu, the heat generated from the chip is efficient because it exists in a larger area than the chip on which the intermediate layer 401 configured as described above is mounted. In addition to being collected well, even if the intermediate layer 401 is formed thick, the thermal expansion coefficient is close to that of the chip or ceramic layer, so that the thermal stress generated in the chip or ceramic can be reduced.
　また、ベース４０２は中間層４０１と同様、配線層を形成する金属であるＡｌやＣｕとＣの複合材料で形成され、熱応力の低減と放熱性の向上に寄与している。このようにベース４０２と中間層４０１に同様の材料を用いることによって、セラミックス絶縁板５０１の上下で熱膨張係数をそろえた部材を配置することとなり、セラミックス絶縁板５０１の上下で発生する歪量の差を低減することできる。そのため、単純な材質による熱応力の低減だけでなく、パワーモジュールの全体構造でも発生する熱応力を低減することが可能となる。 Also, the base 402 is formed of a composite material of Al or Cu and C, which is a metal forming the wiring layer, like the intermediate layer 401, and contributes to reduction of thermal stress and improvement of heat dissipation. Thus, by using the same material for the base 402 and the intermediate layer 401, members having the same thermal expansion coefficient are arranged above and below the ceramic insulating plate 501, and the amount of strain generated above and below the ceramic insulating plate 501 is reduced. The difference can be reduced. Therefore, it is possible not only to reduce the thermal stress by a simple material, but also to reduce the thermal stress generated in the entire structure of the power module.
　セラミックス絶縁板５０１は、高放熱なアルミナや窒化アルミニウムや窒化珪素であり、モジュールに求められる耐電圧を満足する厚さとなっており、板状形状をしている。また、配線層３０１には、上述したようにＩＧＢＴ２０１（絶縁ゲート型バイポーラトランジスタ）とダイオード２０２がはんだや焼結金属などの金属接合部６０１により電気的に接合されている。 The ceramic insulating plate 501 is made of alumina, aluminum nitride, or silicon nitride with high heat dissipation, has a thickness that satisfies the withstand voltage required for the module, and has a plate shape. Further, as described above, the IGBT 201 (insulated gate bipolar transistor) and the diode 202 are electrically joined to the wiring layer 301 by the metal joint portion 601 such as solder or sintered metal.
　セラミックス絶縁板５０１の両面に近接して、配線層３０１よりも高放熱低熱膨張層な中間層４０１とベース４０２を設置することで、パワーモジュールの使用環境下で発生する熱応力低減しつつ高放熱化を図ることが可能となる。 By installing an intermediate layer 401 and a base 402 that are higher in heat dissipation and lower in thermal expansion than the wiring layer 301 in the vicinity of both surfaces of the ceramic insulating plate 501, high heat dissipation is achieved while reducing thermal stress generated in the use environment of the power module. Can be achieved.
　また、本実施形態では後述する作製方法で、配線層３０１、中間層４０１、セラミックス絶縁板５０１、ベース４０２をそれぞれ一体として作製しているため、それぞれの部材間に接合材料（例えばろう材など）が配置されない構造、つまりそれぞれの部材が他の部材を介さず直接接合する構造となっている。したがって、配線、中間層、ベース部材を予め用意してろう材などで接合する構造よりも熱抵抗の低減や生産性の向上が可能なパワーモジュールの提供が可能となる。 Further, in this embodiment, the wiring layer 301, the intermediate layer 401, the ceramic insulating plate 501, and the base 402 are integrally manufactured by a manufacturing method to be described later, so that a bonding material (for example, a brazing material) is provided between the respective members. Is not arranged, that is, each member is directly joined without any other member. Therefore, it is possible to provide a power module capable of reducing thermal resistance and improving productivity as compared with a structure in which wiring, an intermediate layer, and a base member are prepared in advance and joined with a brazing material or the like.
　また、低熱膨張層となる中間層４０１及びベース４０２をセラミックス絶縁板５０１の両面に設置したため、上述したように基板作製時やチップ接合時の全体の反りを小さくすることが可能となる。そのため、放熱面となる図２に示す点線ＢＢ’部をグリスを介して冷却器に取り付ける際、厚さばらつきが減少するので、低熱伝導なグリス厚さが小さくなり熱抵抗の増加を低減できる。 In addition, since the intermediate layer 401 and the base 402 serving as the low thermal expansion layer are provided on both surfaces of the ceramic insulating plate 501, as described above, it is possible to reduce the overall warpage during substrate fabrication and chip bonding. Therefore, when the dotted line BB ′ portion shown in FIG. 2 serving as a heat radiating surface is attached to the cooler via grease, the thickness variation is reduced, so that the low thermal conductive grease thickness is reduced and the increase in thermal resistance can be reduced.
　続いて、図３を用いて本発明に関するパワーモジュール１０１の製造方法について説明する。まず、図３(ａ）に示すように、溶融金属を含浸後に低熱膨張かつ高放熱となるように成型された多孔質な炭素成型体４０１ａと４０２ａの間にセラミックス絶縁板５０１を挿入し、金型７０１，７０２，７０３，７０４で固定することで、それぞれの位置決めをする。 Then, the manufacturing method of the power module 101 regarding this invention is demonstrated using FIG. First, as shown in FIG. 3 (a), a ceramic insulating plate 501 is inserted between porous carbon molded bodies 401a and 402a molded so as to have low thermal expansion and high heat dissipation after impregnation with molten metal. Each positioning is performed by fixing with the molds 701, 702, 703, and 704.
　また、金型７０３は炭素成型体４０１ａよりも厚くなるように構成されている。言い換えると、金型７０４と炭素成型体４０１の間には空間３０１ａが形成されることとなる。このように金型７０３を炭素成型体４０１ａよりも大きく構成することによって、同時に配線層３０１を作製することが可能となる。 Further, the mold 703 is configured to be thicker than the carbon molded body 401a. In other words, a space 301 a is formed between the mold 704 and the carbon molded body 401. By configuring the mold 703 larger than the carbon molded body 401a as described above, the wiring layer 301 can be manufactured at the same time.
　また、金型は簡易形状である平板の積層体で構成されている。そのため簡易な方法で離型剤をムラ無く塗布でき、平面方向や積層方向に多数並べて一括で製造することが可能となる。 Also, the mold is composed of a flat laminate with a simple shape. Therefore, it is possible to apply the release agent without any unevenness by a simple method, and it is possible to manufacture in a lump by arranging a large number in the plane direction or the stacking direction.
　図３（ａ）に示したようにセラミックス絶縁板５０１の両側に炭素成型体４０１ａ、４０２ａを配置し、金型７０１，７０２，７０３，７０４での固定が終了すると、溶融金属を炭素成型体４０１ａ、４０２ａに含浸させる工程に移る。その工程を示すのが図３(ｂ）である。図３（ｂ）に示すように、溶融金属であるＡｌやＣｕ、それらの合金を含浸させると、多孔質な炭素成型体４０１ａと４０２ａ内に溶融金属が含浸し、低熱膨張かつ高放熱なＡｌ-ＣあるいはＣｕ-Ｃで構成される中間層４０１、ベース４０２が形成される。さらに、図３（ａ）で示した空間３０１ａにも同時に溶融金属が流れ込み、低電気抵抗なＡｌあるいはＣｕで構成される配線層３０１が形成される。 As shown in FIG. 3 (a), the carbon molded bodies 401a and 402a are arranged on both sides of the ceramic insulating plate 501, and when the fixing with the molds 701, 702, 703 and 704 is completed, the molten metal is replaced with the carbon molded body 401a. , 402a. This process is shown in FIG. As shown in FIG. 3B, when impregnated with molten metal such as Al or Cu, or an alloy thereof, the porous carbon molded bodies 401a and 402a are impregnated with the molten metal, and have low thermal expansion and high heat dissipation. An intermediate layer 401 and a base 402 made of -C or Cu-C are formed. Furthermore, molten metal simultaneously flows into the space 301a shown in FIG. 3A, and a wiring layer 301 made of Al or Cu having low electrical resistance is formed.
　さらに、同時に多孔質な炭素成型体４０１ａと４０２ａから染み出た溶融金属のスキン層３０２により、中間層４０１、ベース４０２とセラミックス絶縁板５０１の接合が行われる。溶融金属による接合部が極薄いため、中間層４０１、ベース４０２とセラミックス絶縁板５０１との距離が小さくなり、熱抵抗の増加を抑えられ放熱性を向上することが可能となる。 Furthermore, the intermediate layer 401, the base 402 and the ceramic insulating plate 501 are joined together by the molten metal skin layer 302 that has exuded from the porous carbon molded bodies 401 a and 402 a. Since the joint portion made of molten metal is extremely thin, the distance between the intermediate layer 401 and the base 402 and the ceramic insulating plate 501 is reduced, and an increase in heat resistance can be suppressed and heat dissipation can be improved.
　溶融金属の含浸は、溶けた金属の中に浸漬、あるいは溶けた金属を注入することで行う。含浸中に未充填部ができないよう加圧を付与してもよい。この時、ＡｌやＣｕの融点以上の温度となっているため、冷却時に熱応力が発生する。本発明の構造では、セラミックスの両側に低熱膨張部を設置したので、片側だけに設置するよりも冷却時の熱応力の発生や反りを小さくすることが可能となる。 The impregnation of molten metal is performed by dipping in molten metal or injecting molten metal. Pressurization may be applied so that an unfilled part is not formed during the impregnation. At this time, since the temperature is higher than the melting point of Al or Cu, thermal stress is generated during cooling. In the structure of the present invention, since the low thermal expansion portions are installed on both sides of the ceramic, it is possible to reduce the generation and warpage of thermal stress during cooling as compared with the case of installing only on one side.
　続いて、図３(ｃ）に示すように、溶融金属を炭素成型体４０１ａ、４０２ａに含浸させた後に金型７０１，７０２，７０３，７０４を外し、複合体１１０を得る。複合体１１０は、ベース４０２、セラミックス絶縁板５０１、中間層４０１、配線層３０１から構成される。 Subsequently, as shown in FIG. 3C, after the molten metal is impregnated into the carbon molded bodies 401a and 402a, the molds 701, 702, 703, and 704 are removed, and the composite 110 is obtained. The composite 110 includes a base 402, a ceramic insulating plate 501, an intermediate layer 401, and a wiring layer 301.
　セラミックス絶縁板５０１の端部Ａを拡大したものを図３（ｃ）内に示す。溶融金属を炭素成型体４０１ａ、４０２ａに含浸させた際、中間層４０１、ベース４０２、セラミックス絶縁板５０１は表面粗さを有しているため、セラミックス絶縁板５０１との間にわずかな隙間が存在することになり、溶融金属で構成されたスキン層３０２が中間層４０１とセラミックス絶縁板５０１、ベース４０２とセラミックス絶縁板５０１の表面全面に亘って形成され接合される。また、中間層４０１、ベース４０２とセラミックス絶縁板５０１との接合と同様、金型７０１から７０４と中間層４０１、ベース４０２、セラミックス絶縁板５０１の間にも溶融金属によるスキン層３０２が形成される。スキン層３０２は、展延性に富むＡｌやＣｕ、それらの合金で形成されているため、中間層４０１、ベース４０２、セラミックス絶縁板５０１の端部で集中する熱応力を分散低減することができ、ＡｌやＣｕ、それらの合金が溶融する高い温度（６００℃以上）から、室温まで冷却する際に発生する熱応力でも中間層４０１、ベース４０２、セラミックス絶縁板５０１が破壊されない。 An enlarged view of the end A of the ceramic insulating plate 501 is shown in FIG. When the molten metal 401a, 402a is impregnated with the molten metal, the intermediate layer 401, the base 402, and the ceramic insulating plate 501 have a surface roughness, so there is a slight gap between them. As a result, the skin layer 302 made of molten metal is formed and bonded over the entire surface of the intermediate layer 401 and the ceramic insulating plate 501, and the base 402 and the ceramic insulating plate 501. Similarly to the joining of the intermediate layer 401 and the base 402 to the ceramic insulating plate 501, a skin layer 302 made of molten metal is also formed between the molds 701 to 704 and the intermediate layer 401, the base 402 and the ceramic insulating plate 501. . Since the skin layer 302 is formed of Al, Cu, or an alloy thereof rich in spreadability, the thermal stress concentrated on the end portions of the intermediate layer 401, the base 402, and the ceramic insulating plate 501 can be dispersed and reduced. The intermediate layer 401, the base 402, and the ceramic insulating plate 501 are not broken even by thermal stress generated when Al, Cu, or an alloy thereof melts to a room temperature from a high temperature (600 ° C. or higher).
　この中で、セラミックス絶縁層５０１に形成したスキン層３０２（図中点線部）は、絶縁沿面距離を設けるために除去する。この際、酸やアルカリを用いたエッチングや、ブラスト処理などを用いる。スキン層３０２は極薄いため、これらの処理で容易に除去可能である。一方、中間層４０１、ベース４０２の外周部に形成したスキン層３０２は、上述したように、中間層４０１、ベース４０２の端部で集中する熱応力を分散低減することができるため、残存させた方が好ましい。 Among these, the skin layer 302 (dotted line portion in the figure) formed on the ceramic insulating layer 501 is removed to provide an insulating creepage distance. At this time, etching using acid or alkali, blasting, or the like is used. Since the skin layer 302 is extremely thin, it can be easily removed by these processes. On the other hand, the skin layer 302 formed on the outer peripheral portion of the intermediate layer 401 and the base 402 is left because the thermal stress concentrated on the end portions of the intermediate layer 401 and the base 402 can be dispersed and reduced as described above. Is preferred.
　最後に図３(ｄ）に示すように、配線層３０１上にＩＧＢＴ２０１とダイオード２０２をＡｌやＣｕよりも融点が低いＳｎ、Ｚｎ、Ｂｉを主体としたはんだ材やＡｌやＣｕの融点よりも低い温度で焼結するＡｇやＣｕのナノ粒子や酸化銀や酸化銅で接合し、金属接合部６０１を形成する。この時、はんだのぬれ性や焼結性を向上して接合強度を上昇させるための表面処理としてめっきをしてもよい。その後、ＩＧＢＴ２０１とダイオード２０２側の表面主電極や制御端子、配線層３０１に外部端子を超音波接合によるワイヤ、リボンをボンディングしてパワーモジュール１０１が完成する。 Finally, as shown in FIG. 3 (d), the IGBT 201 and the diode 202 on the wiring layer 301 are lower in melting point than Sn or Zn or Bi or lower in melting point than Al or Cu. Bonding is performed with Ag or Cu nanoparticles, silver oxide, or copper oxide that are sintered at a temperature to form a metal bonding portion 601. At this time, plating may be performed as a surface treatment for improving the wettability and sinterability of the solder to increase the bonding strength. After that, the power module 101 is completed by bonding a wire or ribbon by ultrasonic bonding of the external terminal to the IGBT 201 and the surface main electrode or control terminal on the diode 202 side and the wiring layer 301.
　このように、本実施形態ではセラミックス絶縁板５０１の両面には、配線層３０１よりも低熱膨張かつ高熱伝導な複合材料であるＡｌ－ＣまたはＣｕ－Ｃが設けられており、当該複合材料が配線層を形成する金属で接合されている。言い換えるとセラミックス絶縁板５０１と複合材料の間にはろう材のような接合材料がない構造となっている。そのため、配線層３０１からベース４０２に至るまでの熱抵抗が小さくなり、放熱性の高いパワーモジュール１０１を提供することが可能となる。 As described above, in this embodiment, Al—C or Cu—C, which is a composite material having lower thermal expansion and higher thermal conductivity than the wiring layer 301, is provided on both surfaces of the ceramic insulating plate 501, and the composite material is connected to the wiring. Bonded with the metal forming the layer. In other words, there is a structure in which there is no bonding material such as a brazing material between the ceramic insulating plate 501 and the composite material. Therefore, the thermal resistance from the wiring layer 301 to the base 402 is reduced, and the power module 101 with high heat dissipation can be provided.
《第一の実施形態の変形例》
　続いて、本発明に関するパワーモジュール構造の第一の実施形態の変形例について説明する。なお、第一の実施形態のパワーモジュールと同様の構成については、上述した第一の実施形態で用いた図面番号と同様の図面番号を用いている。 << Modification of First Embodiment >>
Then, the modification of 1st embodiment of the power module structure regarding this invention is demonstrated. In addition, about the structure similar to the power module of 1st embodiment, the drawing number similar to the drawing number used in 1st embodiment mentioned above is used.
　図４と図５を用いて第一の実施形態の変形例であるパワーモジュール１０１ａを説明する。本実施形態では、中間層４０１やベース４０２の側面に配線層３０１と同様の金属から構成されるスキン層３０２ｂを設ける。図４（ｃ）は、中間層４０１の側面に形成するスキン層３０２ｂの厚さＸと中間層４０１に発生する熱応力の関係を解析した結果である。ベース４０２の側面にスキン層３０２ｂを設けた場合も同様の効果であるため、ここでは省略する。図４（ｂ）は図４（ａ）内に示した点線部を拡大した図である。図４ (ｂ）に示すように、中間層４０１の側面には厚さＸのスキン層３０２ｂが設けられている。図４(ｃ）は、１２５℃から-４０℃に冷却した際に中間層４０１に発生する最大応力を計算した結果である。図中の横軸はスキン層３０２ｂの厚さであり、縦軸はスキン層が無い場合に中間層４０１に発生する最大応力を１とした規格値である。図４(ｃ）の結果から、スキン層３０２ｂの厚さが大きくなるほど、中間層４０１に発生する熱応力の最大値が単調に低減することがわかる。特に、スキン層３０２ｂの厚さＸが１０ｕｍ以上では発生する熱応力が急激に減少する。Ａｌ-ＣやＣｕ-ＣはＡｌやＣｕよりも剛性に乏しく熱応力耐性に劣るが、中間層４０１やベース４０２の端部などの局所領域にスキン層３０２ｂを設けることで発生する熱応力が格段に低減され、信頼性を向上できることがわかった。また、図４(ａ）に示すように、スキン層３０２はチップ２０１や２０２からベース４０２に放熱する熱の流れの主経路上に配置されないので、スキン層３０２の厚さを増加してもチップ２０１や２０２とベース４０２の間の熱抵抗は増加しない。さらに、中間層４０１やベース４０２の側面は、発熱源となるチップ２０１や２０２から最も距離が離れた位置にあり、熱広がりの効果を必要としないため、放熱性を悪化させずに信頼性を向上することが可能となる。 A power module 101a, which is a modification of the first embodiment, will be described with reference to FIGS. In this embodiment, a skin layer 302 b made of the same metal as the wiring layer 301 is provided on the side surfaces of the intermediate layer 401 and the base 402. FIG. 4C shows the result of analyzing the relationship between the thickness X of the skin layer 302 b formed on the side surface of the intermediate layer 401 and the thermal stress generated in the intermediate layer 401. Since the same effect is obtained when the skin layer 302b is provided on the side surface of the base 402, it is omitted here. FIG. 4B is an enlarged view of the dotted line portion shown in FIG. As shown in FIG. 4B, a skin layer 302b having a thickness X is provided on the side surface of the intermediate layer 401. FIG. 4C shows the result of calculating the maximum stress generated in the intermediate layer 401 when cooled from 125 ° C. to −40 ° C. The horizontal axis in the figure is the thickness of the skin layer 302b, and the vertical axis is a standard value where the maximum stress generated in the intermediate layer 401 is 1 when there is no skin layer. From the result of FIG. 4C, it can be seen that the maximum value of the thermal stress generated in the intermediate layer 401 monotonously decreases as the thickness of the skin layer 302b increases. In particular, when the thickness X of the skin layer 302b is 10 μm or more, the generated thermal stress is rapidly reduced. Al—C and Cu—C are less rigid and inferior in thermal stress than Al and Cu, but the thermal stress generated by providing the skin layer 302b in a local region such as the end of the intermediate layer 401 or the base 402 is remarkably high. It was found that the reliability can be improved. Further, as shown in FIG. 4A, the skin layer 302 is not disposed on the main path of the heat flow radiating heat from the chips 201 and 202 to the base 402, so that the chip is increased even if the thickness of the skin layer 302 is increased. The thermal resistance between 201 and 202 and the base 402 does not increase. Furthermore, the side surfaces of the intermediate layer 401 and the base 402 are located at the furthest distance from the chips 201 and 202 that are the heat generation sources, and do not require the effect of heat spreading. It becomes possible to improve.
　続いて、図５に中間層４０１やベース４０２の側面の表面粗さを大きくした例を示す。図５（ｂ）は図５（ａ）内に示した点線部を拡大した図である。図５（ｂ）に示すよう、図５（ｂ）では、中間層４０１ｂ１とベース４０２ｂ１の端部にスキン層３０２ｂの厚さを厚く形成できるように、中間層４０１ｂ１やベース４０２ｂ１の表面粗さを大きくしている。また、図５(ｃ）に示すように、中間層４０１ｃ１やベース４０２ｃ１の側面部にディンプル(凹部）を形成してもよい。これにより、スキン層３０２ｂの体積が大きくなるため、中間層４０１やベース４０２の端部に発生する熱応力を低減する効果が大きくなる。 Subsequently, FIG. 5 shows an example in which the surface roughness of the side surfaces of the intermediate layer 401 and the base 402 is increased. FIG.5 (b) is the figure which expanded the dotted-line part shown in Fig.5 (a). As shown in FIG. 5B, in FIG. 5B, the surface roughness of the intermediate layer 401b1 and the base 402b1 is set so that the thickness of the skin layer 302b can be increased at the ends of the intermediate layer 401b1 and the base 402b1. It is getting bigger. Further, as shown in FIG. 5C, dimples (concave portions) may be formed on the side surfaces of the intermediate layer 401c1 and the base 402c1. Thereby, since the volume of the skin layer 302b is increased, the effect of reducing the thermal stress generated at the end portions of the intermediate layer 401 and the base 402 is increased.
　図６と図７を用いて第一の実施形態の変形例であるパワーモジュール１０１ｂを説明する。本実施形態では、中間層４０１やベース４０２とセラミックス絶縁板５０１との界面に形成するスキン層３０２ａの厚さを増加させた形態である。図６（ｃ）は、中間層４０１とセラミックス絶縁板５０１の間に形成させるスキン層３０２ａの厚みＹと中間層４０１に発生する熱応力の関係を解析した結果である。ベース４０２とセラミックス絶縁板５０１の間に形成させるスキン層３０２ａを設けた場合も同様の効果であるため、ここでは省略する。図６（ｂ）は図６（ａ）内に示した点線部を拡大した図である。図６ (ｂ）に示すように、中間層４０１の底面に厚さＹのスキン層３０２ａを設けている。図６(ｃ）は、１２５℃から-４０℃に冷却した際に中間層４０１に発生する最大応力を計算した結果である。図中の横軸はスキン層３０２ａの厚さであり、縦軸はスキン層が無い場合に中間層４０１に発生する最大応力を１とした規格値である。図６(ｃ）の結果から、スキン層３０２の厚さが大きくなるほど、中間層４０１に発生する熱応力の最大値が単調に低減することがわかる。特に、スキン層３０２ａの厚さＹが５０ｕｍ以上では発生する熱応力が急激に減少する。そのため、スキン層３０２ａの厚さが５０ｕｍ以上では、発生する熱応力をより低減できることがわかる。 A power module 101b, which is a modification of the first embodiment, will be described with reference to FIGS. In the present embodiment, the thickness of the skin layer 302a formed at the interface between the intermediate layer 401 or the base 402 and the ceramic insulating plate 501 is increased. FIG. 6C shows the result of analyzing the relationship between the thickness Y of the skin layer 302 a formed between the intermediate layer 401 and the ceramic insulating plate 501 and the thermal stress generated in the intermediate layer 401. Since the same effect is obtained when the skin layer 302a formed between the base 402 and the ceramic insulating plate 501 is provided, the description is omitted here. FIG. 6B is an enlarged view of the dotted line portion shown in FIG. As shown in FIG. 6B, a skin layer 302a having a thickness Y is provided on the bottom surface of the intermediate layer 401. FIG. 6C shows the result of calculating the maximum stress generated in the intermediate layer 401 when cooled from 125 ° C. to −40 ° C. In the drawing, the horizontal axis represents the thickness of the skin layer 302a, and the vertical axis represents a standard value where the maximum stress generated in the intermediate layer 401 is 1 when there is no skin layer. From the result of FIG. 6C, it can be seen that the maximum value of the thermal stress generated in the intermediate layer 401 monotonously decreases as the thickness of the skin layer 302 increases. In particular, when the thickness Y of the skin layer 302a is 50 μm or more, the generated thermal stress is rapidly reduced. Therefore, it can be seen that when the thickness of the skin layer 302a is 50 μm or more, the generated thermal stress can be further reduced.
　続いて、図７に中間層４０１やベース４０２のセラミックス絶縁板５０１と対向する面の表面粗さを大きくした例を示す。図７（ｂ）は図７（ａ）内に示した点線部を拡大した図である。図６（ｂ）では、中間層４０１ｄ１やベース４０２ｄ１とセラミックス絶縁板５０１との界面のスキン層３０２ａの厚さを厚く形成できるよう、中間層４０１ｄ１やベース４０２ｄ１のセラミックス絶縁板５０１側の表面粗さを大きくしている。また、図７(ｃ）に示すように、中間層４０１ｅ１やベース４０２ｅ１のセラミックス絶縁板５０１側の表面にディンプル(凹部）を形成してもよい。これにより、スキン層３０２ａの体積が大きくなるため、中間層４０１やベース４０２の端部に発生する熱応力を低減可能となる。このような構成にすることによって、中間層４０１やベース４０２の端部に発生する熱応力を分散して低減させることができ、信頼性の高いパワーモジュールを提供することが可能となる。 Subsequently, FIG. 7 shows an example in which the surface roughness of the surface of the intermediate layer 401 and the base 402 facing the ceramic insulating plate 501 is increased. FIG.7 (b) is the figure which expanded the dotted-line part shown in Fig.7 (a). In FIG. 6B, the surface roughness of the intermediate layer 401d1 and the base 402d1 on the ceramic insulating plate 501 side so that the thickness of the skin layer 302a at the interface between the intermediate layer 401d1 and the base 402d1 and the ceramic insulating plate 501 can be increased. Has increased. Further, as shown in FIG. 7C, dimples (concave portions) may be formed on the surface of the intermediate layer 401e1 or the base 402e1 on the ceramic insulating plate 501 side. Thereby, since the volume of the skin layer 302a becomes large, the thermal stress generated at the end portions of the intermediate layer 401 and the base 402 can be reduced. With such a configuration, it is possible to disperse and reduce the thermal stress generated at the end portions of the intermediate layer 401 and the base 402, and it is possible to provide a highly reliable power module.
　図８には、本発明に関するパワーモジュール１０１の変形例の一例であるパワーモジュール１０２の斜視図図８（ａ）とＡＡ’断面図８ (ｂ）をそれぞれに示す。本実施形態では、鋳造時に形成するスキン層３０２による中間層４６１やベース４６２の応力低減効果を熱応力が最も大きくなる中間層４６１やベース４６２の角部に作用させることができる構造としている。言い換えると、中間層４６１やベース４６２の角部にスキン層３０２を厚く全面に形成している（以下：中間層４６１やベース４６２の角部近傍に形成したスキン層をメタライズ層３０３とする。）。本変形例では、図８（ａ）に示すとおりパワーモジュール１０１の中間層４０１及びベース４０２の構造と比較し、中間層４６１及びベース４６２の構造が異なっている。より詳細な構造については、図９を用いて説明する。 FIG. 8 is a perspective view of a power module 102 which is an example of a modification of the power module 101 according to the present invention, and FIG. 8A and FIG. In this embodiment, the stress reduction effect of the intermediate layer 461 and the base 462 by the skin layer 302 formed during casting can be applied to the corners of the intermediate layer 461 and the base 462 where the thermal stress is greatest. In other words, the skin layer 302 is thickly formed on the entire corners of the intermediate layer 461 and the base 462 (hereinafter, the skin layer formed near the corners of the intermediate layer 461 and the base 462 is referred to as a metallized layer 303). . In this modification, the structures of the intermediate layer 461 and the base 462 are different from those of the intermediate layer 401 and the base 402 of the power module 101 as shown in FIG. A more detailed structure will be described with reference to FIG.
　図９は、図８に示したパワーモジュール１０２を作製するための工程の一部を示している。図９(ａ）は成型前の炭素成型体４６１ａの形状とセラミックス絶縁板５０１と炭素成型体４６１ａの位置決めを行う金型７０３の内面７０３’（破線部）の上視図を示している。図９(ｂ）は鋳造後の上視断面図である。炭素成型体４６１ａの角部と金型の内面７０３’とは空間を形成しており、その領域に溶融金属で構成されたメタライズ層３０３が形成される。また、図９(ａ）に示すように、炭素成型体４６１ａの全周を小さくせず、角部だけ小さくすることで、金型７０３で位置決めできることで、セラミックス絶縁板５０１と中間層４６１との位置あわせ精度を高めることが可能となる。ベース４６２についても同様の手法で、位置あわせ精度を高めつつベース４６２の角部にスキン層を厚く全面に形成したメタライズ層３０３を設けることができる。 FIG. 9 shows a part of a process for manufacturing the power module 102 shown in FIG. FIG. 9A shows a top view of the shape of the carbon molded body 461a before molding and the inner surface 703 '(broken line portion) of the mold 703 for positioning the ceramic insulating plate 501 and the carbon molded body 461a. FIG. 9B is a top sectional view after casting. A corner portion of the carbon molded body 461a and the inner surface 703 'of the mold form a space, and a metallized layer 303 made of molten metal is formed in that region. Further, as shown in FIG. 9A, the entire circumference of the carbon molded body 461a is not reduced, and only the corners are reduced, so that positioning can be performed with the mold 703, so that the ceramic insulating plate 501 and the intermediate layer 461 can be positioned. It is possible to increase the alignment accuracy. The base 462 can also be provided with a metallized layer 303 having a thick skin layer formed on the entire surface at the corners of the base 462 while improving the alignment accuracy in the same manner.
　また、図８(ａ）に示すように、中間層４０１やベース４０２の角部は、発熱源となるチップ２０１や２０２から最も距離が離れた位置にあり、熱広がり向上による放熱性向上の効果が小さいため、放熱性を悪化させずに信頼性を向上することが可能となる。なお、本変形例では中間層４６１（またはベース４６２）の角部をＬ字型に欠損させ、当該中間層４６１（またはベース４６２）の４つの面それぞれに凸部４６１ｂを残す構造としているが、角部のみを切り落とす形としても良い。ただし、本変形例のように中間層４６１（またはベース４６２）をＬ字型に欠損させ、凸部４６２ｂを有する構造とした方が、メタライズ層３０３の体積を大きくできるため、熱応力を低減する構造としては好ましい。なお、メタライズ層３０３は凸部４６２ｂと同一平面上まで設けられる構造となっている方が応力緩和の観点から好ましい。 Further, as shown in FIG. 8A, the corners of the intermediate layer 401 and the base 402 are located at the furthest distance from the chips 201 and 202 serving as heat generation sources, and the effect of improving heat dissipation by improving the heat spread. Therefore, it is possible to improve the reliability without deteriorating the heat dissipation. In this modification, the corner portion of the intermediate layer 461 (or the base 462) is missing in an L shape, and the convex portions 461b are left on the four surfaces of the intermediate layer 461 (or the base 462). It is also possible to cut off only the corners. However, it is possible to increase the volume of the metallized layer 303 and reduce the thermal stress when the intermediate layer 461 (or the base 462) is deficient in an L shape and has a convex portion 462b as in this modification. The structure is preferable. Note that the metallized layer 303 preferably has a structure provided up to the same plane as the convex portion 462b from the viewpoint of stress relaxation.
　続いて、本発明に関するパワーモジュールの変形例の一例であるパワーモジュール１０３の斜視図図１０（ａ）とＡＡ’断面図図１０ (ｂ）をそれぞれ示す。本変形例では、ベース４７２の底面の大部分に配線層３０１と同様の金属から構成されるメタライズ層３０３を設置することで、セラミックス絶縁板５０１をはさみ、配線層３０１、中間層４０１、ベース４７２、メタライズ層３０３と上下を略対称な構成にすることで、温度増減に伴う反りの発生をより抑制した構成としている。図１１（ａ）～（ｃ）は、図１０に示したパワーモジュール１０３を作製するための工程の一部を示している。図１１(ａ）に示すように、炭素成型体４７２ａに突起４７３ａ（破線部）を設けることで、金型７０４との間にメタライズ層３０３を作製するための空間を設けることが可能となる。つまり、突起の高さがメタライズ層３０３となり、反りが小さくなるメタライズ層３０３の厚さを再現よく作製できる。また、突起は炭素成型体４７２ａと一体化されているため、メタライズ層３０３の平面方向のばらつきも小さく作製可能となる。なお、このメタライズ層３０３はベース４７２の突起部４７３と同一平面上まで設けられている方が応力緩和の観点から好ましい。 Subsequently, a perspective view of a power module 103, which is an example of a modification of the power module according to the present invention, is shown in FIG. In this modification, a metallized layer 303 made of the same metal as that of the wiring layer 301 is disposed on most of the bottom surface of the base 472 so that the ceramic insulating plate 501 is sandwiched between the wiring layer 301, the intermediate layer 401, and the base 472. In addition, the metallized layer 303 and the upper and lower sides are configured to be substantially symmetrical so that the occurrence of warpage due to temperature increase and decrease is further suppressed. FIGS. 11A to 11C show a part of a process for manufacturing the power module 103 shown in FIG. As shown in FIG. 11A, by providing a protrusion 473a (broken line portion) on the carbon molded body 472a, it is possible to provide a space for forming the metallized layer 303 between the mold 704. That is, the height of the protrusion becomes the metallized layer 303, and the thickness of the metallized layer 303 with a small warp can be manufactured with good reproducibility. In addition, since the protrusion is integrated with the carbon molded body 472a, the variation in the planar direction of the metallized layer 303 can be made small. The metallized layer 303 is preferably provided up to the same plane as the projection 473 of the base 472 from the viewpoint of stress relaxation.
　このようにして作製されたパワーモジュール１０３は、基板作製時やチップ接合時の全体の反りを小さくすることが可能であり、放熱面をグリスを介して冷却器に取り付ける際、厚さばらつきが減少するので、低熱伝導なグリス厚さが小さくなり熱抵抗の増加を低減できる。 The power module 103 manufactured in this way can reduce the overall warpage during substrate manufacturing and chip bonding, and the thickness variation is reduced when the heat radiation surface is attached to the cooler via grease. As a result, the grease thickness with low thermal conductivity is reduced, and the increase in thermal resistance can be reduced.
《第二の実施形態》　続いて、本発明に関するパワーモジュール構造の第二の実施形態について説明する。なお、第一の実施形態のパワーモジュールと同様の構成については、上述した第一の実施形態で用いた図面番号と同様の図面番号を用いている。 << 2nd embodiment >> Then, 2nd embodiment of the power module structure regarding this invention is described. In addition, about the structure similar to the power module of 1st embodiment, the drawing number similar to the drawing number used in 1st embodiment mentioned above is used.
　第二の実施形態にかかるパワーモジュール１０４を図１２に示す。本実施形態と第一の実施形態の相違点は、ベース４０２の面積をセラミックス絶縁板５０１よりも広くした点が異なる。 FIG. 12 shows a power module 104 according to the second embodiment. The difference between this embodiment and the first embodiment is that the area of the base 402 is wider than the ceramic insulating plate 501.
　図１２のセラミックス絶縁板５０１の端部Ａを拡大した拡大図も図１２中に示し、ベース４０２のセラミックス絶縁板５０１設置面に凹部４２２を設けた際の効果を説明する。この凹部４２２は、底面部４２２ａと側壁面部４２２ｂから構成される。 12 is an enlarged view of the end portion A of the ceramic insulating plate 501 shown in FIG. 12, and the effect when the concave portion 422 is provided on the ceramic insulating plate 501 installation surface of the base 402 will be described. The concave portion 422 includes a bottom surface portion 422a and a side wall surface portion 422b.
　図１３は、各形状で熱応力を解析した結果である。図１３(ａ）はベース４０２のセラミックス絶縁板５０１設置面に凹部を設けた形状、(ｂ）はセラミックス絶縁板５０１設置面に凹部を設けない形状、(ｃ）は図２（第一の実施形態）の形状である。１２５℃から-４０℃に冷却した際に発生する応力を計算した結果を示しており、セラミックス絶縁板５０１設置面に凹部を設けることで発生する熱応力の最大値を低減していることがわかる。 FIG. 13 shows the result of analyzing the thermal stress in each shape. 13A shows a shape in which a concave portion is provided on the ceramic insulating plate 501 installation surface of the base 402, FIG. 13B shows a shape in which no concave portion is provided on the ceramic insulating plate 501 installation surface, and FIG. Shape). The result of calculating the stress generated when cooling from 125 ° C. to −40 ° C. is shown, and it can be seen that the maximum value of the generated thermal stress is reduced by providing a recess on the ceramic insulating plate 501 installation surface. .
　また、図１４に端部近傍の応力特異性を表すため両対数で表示した結果を示す。図１３(ａ）の構造が最も熱応力が小さい構造であり、ベース４０２やセラミックス絶縁板５０１の破壊を防止可能な構造となっていることがわかる。これは、ベース４０２に凹部を設けることによって壁面にセラミックス絶縁板５０１と凹部４２２の側壁面部４２２ｂが当接する形となり、中間層４０１などが積層している積層方向だけでなく、他の方向（側壁面部４２２ｂが当接する方向）にも応力を逃がすことができ、応力を分散させることができるためであると考えられる。 In addition, FIG. 14 shows the results displayed in double logarithm to show the stress singularity near the edge. It can be seen that the structure shown in FIG. 13A has the smallest thermal stress and can prevent the base 402 and the ceramic insulating plate 501 from being broken. This is because by providing a recess in the base 402, the ceramic insulating plate 501 and the side wall surface 422b of the recess 422 come into contact with the wall surface, and not only in the stacking direction in which the intermediate layer 401 and the like are stacked, but also in other directions (sidewalls). It is considered that the stress can be released also in the direction in which the surface portion 422b abuts and the stress can be dispersed.
　続いて、図１５を用いて本実施形態に関するパワーモジュール１０４の製造方法を説明する。なお、第一の実施形態と同様の点の説明は重複するため省くこととする。 Subsequently, a method for manufacturing the power module 104 according to this embodiment will be described with reference to FIG. In addition, since the description of the same point as 1st embodiment overlaps, it shall be abbreviate | omitted.
　本実施形態では、多孔質な炭素成型体４０１ａと当該炭素成型体４０１ａよりも幅広で凹部を有する炭素成型体４０２ｂを用意する。この炭素成型体４０２ｂは、両側をセラミックス絶縁板５０１よりも広くするようにしている。また、この構造に合わせて金型８０１の水平方向の厚さを金型７０３の水平方向の厚さよりも薄くしている。 In this embodiment, a porous carbon molded body 401a and a carbon molded body 402b that is wider than the carbon molded body 401a and has a recess are prepared. The carbon molded body 402b is configured such that both sides are wider than the ceramic insulating plate 501. Further, according to this structure, the thickness of the mold 801 in the horizontal direction is made thinner than the thickness of the mold 703 in the horizontal direction.
　セラミックス絶縁板５０１よりも広くした成型体４０２ｂの両側にザグリをいれることで、セラミックス板５０１の設置面のセラミックス板５０１の位置決めを金型を用いず容易にかつ高精度に行うことが可能となる。 By placing counterbore on both sides of the molded body 402b wider than the ceramic insulating plate 501, it is possible to easily and accurately position the ceramic plate 501 on the installation surface of the ceramic plate 501 without using a mold. .
　このようにベース４０２の面積をセラミックス絶縁板５０１よりも広くすることによって、ＩＧＢＴ２０１とダイオード２０２から発生したセラミックス絶縁板５０１に伝達した熱がベース４０２の面内方向に広がり、第一の実施形態の図２の放熱面積ＢＢ’よりも広い面積ＣＣ’で放熱できる。したがって、より放熱性が向上したパワーモジュールを提供することが可能となる。また、ベース４０２のセラミックス絶縁板５０１を当接させる部分に凹部４２２を設け、その凹部４２２にセラミックス絶縁板５０１を配置する（すなわち、凹部４２２の側壁面部４２２ｂに当接させる）事によって、さらに熱応力を低減することが可能となる。 Thus, by making the area of the base 402 wider than the ceramic insulating plate 501, the heat transmitted to the ceramic insulating plate 501 generated from the IGBT 201 and the diode 202 spreads in the in-plane direction of the base 402, and the first embodiment Heat can be radiated in an area CC ′ wider than the heat radiating area BB ′ in FIG. Therefore, it is possible to provide a power module with improved heat dissipation. Further, a concave portion 422 is provided in a portion of the base 402 where the ceramic insulating plate 501 is brought into contact, and the ceramic insulating plate 501 is disposed in the concave portion 422 (that is, brought into contact with the side wall surface portion 422b of the concave portion 422). The stress can be reduced.
《第三の実施形態》
　続いて、本発明に関するパワーモジュール構造の第三の実施形態について説明する。なお、第一の実施形態のパワーモジュールと同様の構成については、上述した第一の実施形態で用いた図面番号と同様の図面番号を用いている。 << Third embodiment >>
Next, a third embodiment of the power module structure relating to the present invention will be described. In addition, about the structure similar to the power module of 1st embodiment, the drawing number similar to the drawing number used in 1st embodiment mentioned above is used.
　本実施形態にかかるパワーモジュールが第一の実施形態と大きく異なる点はその製造方法である。本発明に関するパワーモジュールの製造方法の変形例を図１６を用いて説明する。 The power module according to this embodiment is greatly different from the first embodiment in its manufacturing method. A modification of the power module manufacturing method according to the present invention will be described with reference to FIG.
　図１６（ａ）は溶融金属を入れる前の状態を示すものである。本実施形態では図１６（ａ）に示すように、多孔質な炭素成型体４０１ａの周縁部の一部に突起部４０１ｂを設ける構成としている。このような構成にすることによって事、配線層３０１を形成するための金型を省略できる。そのため、第一の実施形態のように金型７０１、７０２、７０３を一体とした金型９０１を使用することができる。さらに、このように金型９０１を単純な構造とすることができるため、複数個の複合材２１０を一括で作製することができ、生産性が向上する。 FIG. 16 (a) shows a state before the molten metal is added. In this embodiment, as shown to Fig.16 (a), it is set as the structure which provides the protrusion part 401b in a part of peripheral part of the porous carbon molding 401a. By adopting such a configuration, a mold for forming the wiring layer 301 can be omitted. Therefore, a mold 901 in which the molds 701, 702, and 703 are integrated as in the first embodiment can be used. Further, since the mold 901 can have a simple structure as described above, a plurality of composite materials 210 can be manufactured at once, and productivity is improved.
　その後、図１６（ｂ）に示すように溶融金属を流し込み、炭素成型体４０１ａ及び４０１ｂ、炭素成型体４０２ａにそれぞれ金属を含浸させ、凸部４１１ｂに囲まれた凹部を有する中間層４１１と、ベース４０２が形成される。なお、このとき凸部４１１ｂに囲まれた凹部には配線層３０１が形成される。 Thereafter, as shown in FIG. 16 (b), molten metal is poured into the carbon molded bodies 401a and 401b and carbon molded body 402a, respectively, and an intermediate layer 411 having a concave portion surrounded by the convex portion 411b, and a base 402 is formed. At this time, the wiring layer 301 is formed in the concave portion surrounded by the convex portion 411b.
　そして、金型９０１、７０２が取り外され、図１６（ｃ）に示す複合材２１０が取り出される。 Then, the molds 901 and 702 are removed, and the composite material 210 shown in FIG.
　最後に両端を研磨、掘削等の手段を用いて中間層４１１の端部を削りパワーモジュール１０５を得る。 Finally, the ends of the intermediate layer 411 are shaved using means such as polishing and excavating both ends to obtain the power module 105.
　以上、本実施形態では炭素成型体４０１ａの周縁部に突起部４０１ｂを設ける構成とした炭素成型体を用いてパワーモジュールを作製する。この凸部４０１ｂを有する炭素成型体を用いることによって、金型を簡素化できるとともに、炭素成型体４０１ａの厚み方向の拘束が高まるため、中間層４０１、ベース４０２とセラミックス絶縁板５０１のスキン層３０２の厚みを減少させることが可能となる。そのため、セラミックス絶縁板５０１と中間層４１１、及びセラミックス層５０１とベース４０２の距離を近づけることが可能となり、放熱性がより向上する。また別の効果として、少ない数の金型で固定できるので生産性が向上する。 As mentioned above, in this embodiment, a power module is produced using the carbon molded object which provided the protrusion 401b in the peripheral part of the carbon molded object 401a. By using the carbon molded body having the convex portions 401b, the mold can be simplified and the restraint in the thickness direction of the carbon molded body 401a is increased. Therefore, the intermediate layer 401, the base 402, and the skin layer 302 of the ceramic insulating plate 501. It becomes possible to reduce the thickness of the. Therefore, it is possible to reduce the distance between the ceramic insulating plate 501 and the intermediate layer 411, and the distance between the ceramic layer 501 and the base 402, and heat dissipation is further improved. Another advantage is that productivity can be improved because it can be fixed with a small number of molds.
《第四の実施形態》
　続いて、本発明に関するパワーモジュール構造の第四の実施形態について説明する。なお、第一の実施形態のパワーモジュールと同様の構成については、上述した第一の実施形態で用いた図面番号と同様の図面番号を用いている。 << Fourth Embodiment >>
Next, a fourth embodiment of the power module structure relating to the present invention will be described. In addition, about the structure similar to the power module of 1st embodiment, the drawing number similar to the drawing number used in 1st embodiment mentioned above is used.
　本実施形態に関するパワーモジュールの構造を図１７を用いて説明する。本実施形態が第一の実施形態のパワーモジュールと異なる点は、セラミックス５０１の上側に存在する中間層４２１の構造であり、中間層４２１は土台部４２１ａから突出した突起部４２１ｂが存在する構造となっている点である。 The structure of the power module according to this embodiment will be described with reference to FIG. This embodiment is different from the power module of the first embodiment in the structure of the intermediate layer 421 that exists on the upper side of the ceramic 501, and the intermediate layer 421 has a structure in which a protruding portion 421 b that protrudes from the base portion 421 a exists. It is a point.
　続いて、本実施形態のパワーモジュール１０６の製造方法の一例について図１８、１９を用いて説明する。 Subsequently, an example of a method for manufacturing the power module 106 of the present embodiment will be described with reference to FIGS.
　上記構成により、新たに設けた突起部４２１ｂの体積分だけ配線３０１と中間部４２１の合成熱膨張係数が減少するので、発生する熱応力を低減することが可能となる。そのため、より信頼性の高いパワーモジュール１０６を提供することできる。なお、突起部４２１ｂは、配線層３０１に比較して電気抵抗が高いため、チップ搭載部など低電気抵抗が必要な箇所以外に設けた方が好ましい。ここでは省略するが、突起部４２１ｂは、中間層４０１の端部よりも少し内側（チップに近い側）に設けることで、その外側に空間が形成でき、鋳造時にメタライズ層３０３を設けることが可能となり、中間層４０１の応力を低減することが可能となる。 With the above configuration, the combined thermal expansion coefficient of the wiring 301 and the intermediate portion 421 is reduced by the volume of the newly provided protrusion 421b, so that it is possible to reduce the generated thermal stress. Therefore, the power module 106 with higher reliability can be provided. Note that the protruding portion 421b has a higher electrical resistance than the wiring layer 301, and thus it is preferable to provide the protruding portion 421b at a location other than a portion where low electrical resistance is required, such as a chip mounting portion. Although omitted here, the protrusion 421b is provided slightly inside (on the side closer to the chip) than the end of the intermediate layer 401, so that a space can be formed outside thereof, and the metallized layer 303 can be provided during casting. Thus, the stress of the intermediate layer 401 can be reduced.
《第五の実施形態》
　続いて、本発明に関するパワーモジュール構造の第五の実施形態について説明する。なお、第一の実施形態のパワーモジュールと同様の構成については、上述した第一の実施形態で用いた図面番号と同様の図面番号を用いている。 << Fifth Embodiment >>
Subsequently, a fifth embodiment of the power module structure according to the present invention will be described. In addition, about the structure similar to the power module of 1st embodiment, the drawing number similar to the drawing number used in 1st embodiment mentioned above is used.
　図１８は本実施形態の複合材３１０の中間層４０１を削除し、上方から見た図である。本実施形態では、図１８に示すように、炭素成型体４３２ａに空間４３２ｂを形成することにより、ベース４０２内に溶湯金属部のみで形成する箇所を作製した。この点が第一の実施形態とは異なる点である。 FIG. 18 is a view seen from above with the intermediate layer 401 of the composite material 310 of this embodiment deleted. In the present embodiment, as shown in FIG. 18, by forming a space 432b in the carbon molded body 432a, a portion formed only by the molten metal portion in the base 402 was produced. This point is different from the first embodiment.
　作製する箇所は、ベース４０２に発生する熱応力が集中するセラミックス絶縁板５０１の端部がよく、さらに角部が効果的である。例えば、図１８に示すように、炭素成型体４４３２のセラミックス絶縁板５０１の四隅に対応する部分に空間４３２ｂを設けるのが好ましい。 The end of the ceramic insulating plate 501 where the thermal stress generated in the base 402 concentrates is good, and the corner is more effective for the part to be manufactured. For example, as shown in FIG. 18, it is preferable to provide spaces 432 b in portions corresponding to the four corners of the ceramic insulating plate 501 of the carbon molded body 4432.
　図１９に本実施形態にかかるパワーモジュール１０５の断面図を示す。またパワーモジュール１０５のＡ部の拡大図を図１９内に示す。Ａｌ-ＣやＣｕ-Ｃの適用により、発生する熱応力量は低減するが、Ａｌ-ＣやＣｕ-ＣはＡｌやＣｕよりも剛性に乏しく熱応力耐性に劣る。そこで、図１９に示したように炭素成体４３２に空間４３２ｂを設けてパワーモジュールを作製することによって、応力集中部のような局所領域をＡｌやＣｕに置き換えたメタライズ層３０３を形成することが可能となる。そのため、Ａｌ-ＣやＣｕ-Ｃの破壊を防止することが可能となり、より信頼性の向上したパワーモジュール１０７を提供することが可能となる。また、図１９に示すように、メタライズ層３０３の角はテーパーとすることでさらに効果が大きくなる。 FIG. 19 shows a cross-sectional view of the power module 105 according to the present embodiment. Moreover, the enlarged view of the A section of the power module 105 is shown in FIG. Application of Al—C or Cu—C reduces the amount of generated thermal stress, but Al—C and Cu—C are less rigid and less resistant to thermal stress than Al and Cu. Therefore, as shown in FIG. 19, by forming a power module by providing a space 432 b in the carbon composite 432, it is possible to form a metallized layer 303 in which a local region such as a stress concentration portion is replaced with Al or Cu. It becomes. Therefore, it becomes possible to prevent the destruction of Al—C and Cu—C, and it is possible to provide the power module 107 with improved reliability. Further, as shown in FIG. 19, the effect is further enhanced by tapering the corners of the metallized layer 303.
《第六の実施形態》
　続いて、本発明に関するパワーモジュール構造の第六の実施形態について説明する。なお、第一の実施形態のパワーモジュールと同様の構成については、上述した第一の実施形態で用いた図面番号と同様の図面番号を用いている。 << Sixth Embodiment >>
Next, a sixth embodiment of the power module structure relating to the present invention will be described. In addition, about the structure similar to the power module of 1st embodiment, the drawing number similar to the drawing number used in 1st embodiment mentioned above is used.
　本発明に関するパワーモジュール１０８の構造を図２０、図２１を用いて説明する。本実施形態は、図２１（ａ）は、本実施形態にかかる炭素成型体４５１を示すもの、図２１（ｂ）は炭素成型体４５１を図２１（ａ）のＡ－Ａ断面から見た図である。図２１に示すように炭素成型体４５１に逆テーパーの空間４５２を形成した点が第一の実施形態と異なっている。 The structure of the power module 108 according to the present invention will be described with reference to FIGS. In this embodiment, FIG. 21 (a) shows a carbon molded body 451 according to this embodiment, and FIG. 21 (b) is a diagram of the carbon molded body 451 viewed from the AA cross section of FIG. 21 (a). It is. As shown in FIG. 21, the point which formed the space 452 of the reverse taper in the carbon molding 451 differs from 1st embodiment.
　炭素成型体４５１に溶融金属を含浸することで、図２０に示す中間層４６１が形成できる。そして中間層４６１が形成されるのと同時に溶融金属が固まって形成された逆テーパー金属部３０４が形成される。含浸前の炭素成型体４５１に逆テーパーの穴を空けることは容易であるため、生産性にも優れている。空間は応力集中する中間層４６１の角部が効果的であり、チップ搭載部から離れた箇所に設けることで熱抵抗の増加を小さくできる。 An intermediate layer 461 shown in FIG. 20 can be formed by impregnating the carbon molding 451 with molten metal. Then, at the same time when the intermediate layer 461 is formed, a reverse tapered metal portion 304 formed by solidifying the molten metal is formed. Since it is easy to make a reverse-tapered hole in the carbon molded body 451 before impregnation, the productivity is excellent. In the space, the corner portion of the intermediate layer 461 where the stress is concentrated is effective, and an increase in thermal resistance can be reduced by providing the corner portion away from the chip mounting portion.
　以上、本実施形態を実施することにより、炭素成型体４５１に逆テーパーの空間４５２を形成し、溶融金属を炭素成型体４５１に含浸させた後に逆テーパー型のメタライズ層３０４を形成できる。そのため配線層３０１と逆テーパー型のメタライズ層３０４を一体にすることができ、配線３０１と中間層４６１の接合強度をアンカー効果で向上させたパワーモジュール１０５を提供することが可能となる。 As described above, by implementing the present embodiment, the inversely tapered metallized layer 304 can be formed after forming the inversely tapered space 452 in the carbon molded body 451 and impregnating the carbon molded body 451 with molten metal. Therefore, the wiring layer 301 and the reverse taper type metallized layer 304 can be integrated, and the power module 105 in which the bonding strength between the wiring 301 and the intermediate layer 461 is improved by the anchor effect can be provided.
　以上、本発明を簡単に纏める。 In the above, the present invention is briefly summarized.
　本発明にかかるパワーモジュールは、炭素を含有する複合材料により構成されるベース部と、当該ベース部に搭載されるセラミックス絶縁板と、当該セラミックス絶縁板に搭載され、前記複合材料で構成される中間層と、当該中間層に形成される配線層と、当該配線層に接合材料を介して接合される半導体素子と、を有し、前記セラミックス絶縁板と前記ベース部、及び前記セラミックス絶縁板と前記中間層は、それぞれ前記配線層を形成する金属で接合される。そのため、配線層からベースに至るまでの熱抵抗が少なくなり、放熱性の高いパワーモジュールを提供することが可能となる。また、本発明ではセラミックス絶縁板５０１の両面には、同じ組成の複合材料が配置されることによって、セラミックス絶縁板５０１の両面で熱膨張係数をそろえることが可能になり、反りの抑制につながる。 A power module according to the present invention includes a base portion made of a composite material containing carbon, a ceramic insulating plate mounted on the base portion, and an intermediate portion made of the composite material mounted on the ceramic insulating plate. A layer, a wiring layer formed on the intermediate layer, and a semiconductor element bonded to the wiring layer via a bonding material, the ceramic insulating plate, the base portion, and the ceramic insulating plate, The intermediate layers are joined with the metal forming the wiring layer. Therefore, the thermal resistance from the wiring layer to the base is reduced, and a power module with high heat dissipation can be provided. Further, in the present invention, the composite material having the same composition is disposed on both surfaces of the ceramic insulating plate 501, whereby the thermal expansion coefficients can be made uniform on both surfaces of the ceramic insulating plate 501, leading to suppression of warpage.
　また、本発明にかかるパワーモジュールは、前記中間層やベース部の側面の凹凸を大きくすることで、鋳造時に形成するＡｌやＣｕで構成されるスキン層の体積を大きくしている。そのため、Ａｌ-ＣやＣｕ-Ｃの端部に集中する応力発生量を緩和することが可能となる。従って、中間層やベース部の破壊を防止することが可能となり、より信頼性を向上したパワーモジュールを提供することが可能となる。 Further, in the power module according to the present invention, the volume of the skin layer made of Al or Cu formed during casting is increased by increasing the unevenness of the side surface of the intermediate layer or the base portion. Therefore, it is possible to reduce the stress generation amount concentrated on the end of Al—C or Cu—C. Therefore, it is possible to prevent the intermediate layer and the base portion from being broken, and it is possible to provide a power module with improved reliability.
　また、本発明にかかるパワーモジュールは、前記セラミックス絶縁板の搭載面側の前記中間層やベース部の表面の凹凸を大きくすることで、鋳造時に形成するＡｌやＣｕで構成されるスキン層の体積を大きくしている。そのため、Ａｌ-ＣやＣｕ-Ｃとセラミックス絶縁板との端部界面に集中する応力発生量を低減することが可能となる。従って、Ａｌ-ＣやＣｕ-Ｃの破壊を防止することが可能となり、より信頼性を向上したパワーモジュールを提供することが可能となる。 Moreover, the power module according to the present invention has a skin layer volume composed of Al or Cu formed during casting by increasing the unevenness of the surface of the intermediate layer or the base portion on the mounting surface side of the ceramic insulating plate. Has increased. Therefore, it is possible to reduce the amount of stress that is concentrated at the end interface between Al—C or Cu—C and the ceramic insulating plate. Therefore, it is possible to prevent the destruction of Al—C and Cu—C, and it is possible to provide a power module with improved reliability.
　また、本発明にかかるパワーモジュールは、前記中間層や前記ベース部の応力集中部のような局所領域に対し、ＡｌやＣｕで置き換えた応力緩和部を全域に形成することが可能となる。従って、Ａｌ-ＣやＣｕ-Ｃで形成した中間層やベース部の破壊を防止することが可能となり、より信頼性を向上したパワーモジュールを提供することが可能となる。 In addition, the power module according to the present invention can form a stress relaxation portion replaced with Al or Cu over the entire region of the local region such as the stress concentration portion of the intermediate layer or the base portion. Therefore, it is possible to prevent the intermediate layer and the base portion formed of Al—C or Cu—C from being broken, and it is possible to provide a power module with improved reliability.
　また、本発明にかかるパワーモジュールは、前記ベースの底面部に突起を設け、残部を前記配線層とすることで、前記セラミックス絶縁板をはさんで上下略対称な構造としている。そのため、熱応力による反りなどの変形量を低減し、放熱面の高さばらつきの発生を防止できる。従って、グリスを介した冷却にあたり、放熱面の高さばらつきに起因した低熱伝導なグリス厚の増加を防止できるので、より放熱性を向上したパワーモジュールを提供することが可能となる。 In the power module according to the present invention, a protrusion is provided on the bottom surface of the base, and the remaining part is the wiring layer, so that the structure is substantially symmetric with respect to the ceramic insulating plate. Therefore, the amount of deformation such as warpage due to thermal stress can be reduced, and the occurrence of variations in the height of the heat radiation surface can be prevented. Therefore, since the increase in the thickness of the grease having low thermal conductivity due to the variation in the height of the heat radiation surface can be prevented in cooling through the grease, it is possible to provide a power module with further improved heat dissipation.
　また、本発明にかかるパワーモジュールは、前記ベース部が前記セラミックス絶縁板よりも大きく構成され、前記ベース部には凹部が設けられ、前記セラミックス絶縁板は、前記凹部に搭載されている。そのため、凹部４２２の側壁面部４２２ｂにセラミックス絶縁板を当接させる事ができ、さらに熱応力を低減することが可能となる。 Further, in the power module according to the present invention, the base portion is configured to be larger than the ceramic insulating plate, the concave portion is provided in the base portion, and the ceramic insulating plate is mounted in the concave portion. Therefore, the ceramic insulating plate can be brought into contact with the side wall surface portion 422b of the recess 422, and thermal stress can be further reduced.
　また、本発明にかかるパワーモジュールは、前記中間層は凹部を有し、当該凹部に配線層が形成されている。そのため、中間層の突起部の体積分だけ配線と中間部の合成熱膨張係数が減少するので、発生する熱応力を低減することが可能となる。 In the power module according to the present invention, the intermediate layer has a recess, and a wiring layer is formed in the recess. Therefore, the combined thermal expansion coefficient between the wiring and the intermediate portion is reduced by the volume of the protruding portion of the intermediate layer, so that the generated thermal stress can be reduced.
　また、本発明にかかるパワーモジュールは、前記ベース部が、当該ベース部のセラミックス絶縁板の隅部と対向する位置に穴を有しており、当該穴には前記配線層を形成する金属が充填されている。そのため、応力集中部のような局所領域に、ＡｌやＣｕで置き換えた応力集中低減部を形成することが可能となる。従って、Ａｌ-ＣやＣｕ-Ｃの破壊を防止することが可能となり、より信頼性を向上したパワーモジュールを提供することが可能となる。 In the power module according to the present invention, the base portion has a hole at a position facing the corner of the ceramic insulating plate of the base portion, and the hole is filled with a metal forming the wiring layer. Has been. Therefore, it is possible to form a stress concentration reduction portion replaced with Al or Cu in a local region such as a stress concentration portion. Therefore, it is possible to prevent the destruction of Al—C and Cu—C, and it is possible to provide a power module with improved reliability.
　また、本発明にかかるパワーモジュールは、前記中間層が、前記配線層から前記セラミックス絶縁板に向かって大きさが小さくなるように逆テーパー部が構成され、前記逆テーパー部と前記セラミックス絶縁板との間には前記配線層を形成する金属が充填されて逆テーパー金属部が構成され、前記逆テーパー金属部と前記配線層とは一体で形成されている。そのため、配線層と逆テーパー金属部を一体にすることができ、配線と中間層の接合強度をアンカー効果で向上させたパワーモジュールを提供することが可能となる。 In the power module according to the present invention, a reverse taper portion is configured such that the intermediate layer decreases in size from the wiring layer toward the ceramic insulation plate, and the reverse taper portion, the ceramic insulation plate, In between, the metal which forms the said wiring layer is filled, and a reverse taper metal part is comprised, and the said reverse taper metal part and the said wiring layer are integrally formed. Therefore, it is possible to provide a power module in which the wiring layer and the reverse tapered metal portion can be integrated, and the bonding strength between the wiring and the intermediate layer is improved by the anchor effect.
　また、本発明にかかるパワーモジュールは、前記配線層はアルミまたは銅で構成され、前記複合材料は、前記配線層を構成する金属と炭素との複合材料である。そのため、ＡｌやＣｕよりも低熱膨張で高放熱なＡｌ－Ｃ、Ｃｕ－Ｃの複合材料を用いているので、信頼性の高いパワーモジュールを提供することが可能である。 In the power module according to the present invention, the wiring layer is made of aluminum or copper, and the composite material is a composite material of metal and carbon constituting the wiring layer. Therefore, since a composite material of Al—C and Cu—C, which has lower thermal expansion and higher heat dissipation than Al and Cu, is used, a highly reliable power module can be provided.
　また、本発明にかかるパワーモジュールの製造方法では、前記セラミックス絶縁板の両面に炭素成型体を金型内に配置する第一の工程と、前記金型内に溶融したアルミまたは溶融した銅を流し込む第二の工程と、前記第二の工程の後に金型を取り外す第三の工程を有する。このようにすることによって、第一の実施形態のパワーモジュールを作製することが可能となる。 In the method for manufacturing a power module according to the present invention, a first step of placing a carbon molded body in the mold on both surfaces of the ceramic insulating plate, and molten aluminum or molten copper are poured into the mold. It has a 3rd process which removes a metal mold | die after a 2nd process and said 2nd process. By doing in this way, it becomes possible to produce the power module of 1st embodiment.
　また、本発明にかかるパワーモジュールの製造方法は、前記セラミックス絶縁板の一方の面に配置される炭素成型体は凹部を有し、前記第一の工程では当該凹部に前記セラミックス絶縁板が配置される。このようにすることによって、第二の実施形態のパワーモジュールを作製することが可能となる。 In the power module manufacturing method according to the present invention, the carbon molded body disposed on one surface of the ceramic insulating plate has a concave portion, and the ceramic insulating plate is disposed in the concave portion in the first step. The By doing in this way, it becomes possible to produce the power module of 2nd embodiment.
　また、本発明にかかるパワーモジュールの製造方法は、前記セラミックス絶縁板の一方の面に配置される炭素成型体は凹部を有し、前記第一の工程では、前記炭素成型体の凹部が形成された面とは反対側の面に前記セラミックス絶縁板が配置される。このようにすることによって、第四の実施形態のパワーモジュールを作製することが可能となる。 In the method for manufacturing a power module according to the present invention, the carbon molded body disposed on one surface of the ceramic insulating plate has a concave portion, and the concave portion of the carbon molded body is formed in the first step. The ceramic insulating plate is disposed on a surface opposite to the surface. By doing in this way, it becomes possible to produce the power module of 4th embodiment.
　また、本発明のパワーモジュールの製造方法において、前記セラミックス絶縁板の一方の面に配置される炭素成型体には穴が設けられ、前記第一の工程では、前記炭素成型体の穴と前記セラミックス絶縁板の隅部が対向するように配置される。このようにすることによって、第五の実施形態のパワーモジュールを作製することが可能となる。 In the method for manufacturing a power module of the present invention, a hole is provided in the carbon molded body disposed on one surface of the ceramic insulating plate, and in the first step, the hole in the carbon molded body and the ceramic are formed. It arrange | positions so that the corner part of an insulating board may oppose. By doing in this way, it becomes possible to produce the power module of 5th embodiment.
　また、本発明にかかるパワーモジュールの製造方法は、前記セラミックス絶縁板の一方の面に配置される炭素成型体は、一方の面よりも当該一方の面に対向する他方の面の方が小さい逆テーパー形状となるように構成され、前記第一の工程では、前記炭素成型体の他方の面が前記セラミックス絶縁板と対向して配置される。このようにすることによって、本発明の第六の実施形態のパワーモジュールを作製することが可能となる。 In the power module manufacturing method according to the present invention, the carbon molded body disposed on one surface of the ceramic insulating plate is opposite in that the other surface facing the one surface is smaller than the one surface. In the first step, the other surface of the carbon molded body is arranged to face the ceramic insulating plate. By doing in this way, it becomes possible to produce the power module of 6th embodiment of this invention.
　以上、本発明の実施形態について詳述したが、本発明は、前記の実施形態に限定されるものではなく、特許請求の範囲に記載された本発明の精神を逸脱しない範囲で、種々の設計変更を行うことができるものである。例えば、前記した実施の形態は本発明を分かりやすく説明するために詳細に説明したものであり、必ずしも説明した全ての構成を備えるものに限定されるものではない。また、ある実施形態の構成の一部を他の実施形態の構成に置き換えることが可能であり、また、ある実施形態の構成に他の実施形態の構成を加えることも可能である。さらに、各実施形態の構成の一部について、他の構成の追加・削除・置換をすることが可能である。 Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.
１０１　パワーモジュール
２０１　ＩＧＢＴ
２０２　ダイオード
３０１　配線
３０２　スキン層
３０３　メタライズ層
４０１　中間層
４０２　ベース
５０１　セラミックス絶縁板
６０１　金属接合部 101 Power module 201 IGBT
202 Diode 301 Wiring 302 Skin layer 303 Metallized layer 401 Intermediate layer 402 Base 501 Ceramic insulating plate 601 Metal junction

Claims (16)

  1. 　炭素を含有する複合材料により構成されるベース部と、
    　当該ベース部に搭載されるセラミックス絶縁板と、
    　当該セラミックス絶縁板に搭載され、前記複合材料で構成される中間層と、
    　当該中間層に形成される配線層と、
    　当該配線層に接合材料を介して接合される半導体素子と、を有するパワーモジュールにおいて、
    　前記セラミックス絶縁板と前記ベース部、及び前記セラミックス絶縁板と前記中間層は、それぞれ前記配線層を形成する金属で接合されることを特徴とするパワーモジュール。     A base composed of a composite material containing carbon;
    A ceramic insulating plate mounted on the base portion;
    An intermediate layer mounted on the ceramic insulating plate and composed of the composite material;
    A wiring layer formed in the intermediate layer;
    In a power module having a semiconductor element bonded to the wiring layer via a bonding material,
    The power module, wherein the ceramic insulating plate and the base portion, and the ceramic insulating plate and the intermediate layer are joined with a metal forming the wiring layer.
  2. 　請求項１に記載のパワーモジュールにおいて、
    　前記中間層及び、あるいは前記ベース部の側面に凹凸部が形成され、
    　前記中間層及び、あるいは前記ベース部の側面の凹凸部表面には前記配線層を形成する金属で構成されたスキン層が形成されることを特徴とするパワーモジュール。     The power module according to claim 1,
    An uneven portion is formed on the side surface of the intermediate layer and / or the base portion,
    The power module, wherein a skin layer made of a metal forming the wiring layer is formed on the intermediate layer and / or the surface of the concavo-convex portion on the side surface of the base portion.
  3. 　請求項１または２に記載のパワーモジュールにおいて、
    　前記中間層及び、あるいは前記ベース部の前記セラミックス絶縁板側の表面に凹凸部が形成され、
    　前記中間層及び、あるいは前記ベース部の前記セラミックス絶縁板側の表面の凹凸部表面には、前記配線層を形成する金属で構成されたスキン層が形成されることを特徴とするパワーモジュール。     The power module according to claim 1 or 2,
    An uneven portion is formed on the surface of the intermediate layer and / or the ceramic insulating plate side of the base portion,
    The power module, wherein a skin layer made of a metal forming the wiring layer is formed on the surface of the intermediate layer and / or the uneven portion of the surface of the base portion on the ceramic insulating plate side.
  4. 　請求項１乃至３のいずれかに記載のパワーモジュールにおいて、
    　前記中間層及び、あるいは前記ベース部の側面部に凸部を有し、当該凸部と同一平面上まで前記配線層を形成する金属で構成されたメタライズ層が形成されていることを特徴とするパワーモジュール。     The power module according to any one of claims 1 to 3,
    A metallized layer made of a metal having a convex portion on the side surface portion of the intermediate layer and / or the base portion and forming the wiring layer up to the same plane as the convex portion is formed. Power module.
  5. 　請求項１乃至４のいずれかに記載のパワーモジュールにおいて、
    前記ベース部の底面に凸部を有し、当該凸部と同一平面上まで前記配線層を形成する金属で構成されたメタライズ層が形成されていることを特徴とするパワーモジュール。     The power module according to any one of claims 1 to 4,
    A power module comprising a metallized layer made of a metal having a convex part on a bottom surface of the base part and forming the wiring layer on the same plane as the convex part.
  6. 　請求項１乃至５のいずれかに記載のパワーモジュールにおいて、
    　前記ベース部は前記セラミックス絶縁板よりも大きく構成され、
    　前記ベース部には凹部が設けられ、
    　前記セラミックス絶縁板は、前記凹部に搭載されていることを特徴とするパワーモジュール。     The power module according to any one of claims 1 to 5,
    The base portion is configured to be larger than the ceramic insulating plate,
    The base portion is provided with a recess,
    The ceramic insulating plate is mounted in the concave portion.
  7. 　請求項１乃至６のいずれかに記載のパワーモジュールにおいて、
    　前記中間層は凸部を有し、当該凸部と同一平面上まで配線層が形成されていることを特徴とするパワーモジュール。     The power module according to any one of claims 1 to 6,
    The power module, wherein the intermediate layer has a convex portion, and a wiring layer is formed on the same plane as the convex portion.
  8. 　請求項１乃至７のいずれかに記載のパワーモジュールにおいて、
    　前記中間層は凸部を有し、当該凸部と同一平面上まで配線層が形成されており、当該配線層に接合材料を介して接合される半導体素子の外周部に当該凸部が存在することを特徴とするパワーモジュール。     The power module according to any one of claims 1 to 7,
    The intermediate layer has a convex portion, and a wiring layer is formed on the same plane as the convex portion, and the convex portion exists on the outer peripheral portion of the semiconductor element joined to the wiring layer via a bonding material. A power module characterized by that.
  9. 　請求項１乃至８に記載のパワーモジュールにおいて、
    　前記ベース部は、当該ベース部のセラミックス絶縁板の隅部と対向する位置に穴を有しており、当該穴には前記配線層を形成する金属が充填されていることを特徴とするパワーモジュール。     The power module according to any one of claims 1 to 8,
    The base part has a hole at a position facing the corner of the ceramic insulating plate of the base part, and the hole is filled with a metal that forms the wiring layer. .
  10. 　請求項１乃至９に記載のパワーモジュールにおいて、
    　前記中間層は、前記配線層から前記セラミックス絶縁板に向かって大きさが小さくなるように逆テーパー部が構成され、
    　前記逆テーパー部と前記セラミックス絶縁板との間には前記配線層を形成する金属が充填されて逆テーパー金属部が構成され、
    　前記逆テーパー金属部と前記配線層とは一体で形成されていることを特徴とするパワーモジュール。     The power module according to claim 1, wherein
    The intermediate layer is configured with a reverse tapered portion so that the size decreases from the wiring layer toward the ceramic insulating plate,
    Between the reverse taper portion and the ceramic insulating plate, a metal that forms the wiring layer is filled to form a reverse taper metal portion,
    The power module, wherein the reverse taper metal part and the wiring layer are integrally formed.
  11. 　請求項１乃至１０のいずれかに記載のパワーモジュールにおいて、
    　前記配線層はアルミまたは銅で構成され、
    　前記複合材料は、前記配線層を構成する金属と炭素との複合材料であることを特徴とするパワーモジュール     The power module according to any one of claims 1 to 10,
    The wiring layer is made of aluminum or copper,
    The composite material is a composite material of metal and carbon constituting the wiring layer.
  12. 　炭素を含有する複合材料により構成されるベース部と、
    　当該ベース部に搭載されるセラミックス絶縁板と、
    　当該セラミックス絶縁板に搭載され、前記複合材料で構成される中間層と、
    　当該中間層に形成される配線層と、
    当該配線層に接合材料を介して接合される半導体素子と、を有するパワーモジュールの製造方法において、
    　前記セラミックス絶縁板の両面に炭素成型体を金型内に配置する第一の工程と、
    　前記金型内に溶融したアルミまたは溶融した銅を流し込む第二の工程と、
    　前記第二の工程の後に金型を取り外す第三の工程を有することを特徴とするパワーモジュールの製造方法。     A base composed of a composite material containing carbon;
    A ceramic insulating plate mounted on the base portion;
    An intermediate layer mounted on the ceramic insulating plate and composed of the composite material;
    A wiring layer formed in the intermediate layer;
    In a method for manufacturing a power module having a semiconductor element bonded to the wiring layer via a bonding material,
    A first step of disposing a carbon molding in the mold on both sides of the ceramic insulating plate;
    A second step of pouring molten aluminum or molten copper into the mold;
    A method of manufacturing a power module, comprising a third step of removing the mold after the second step.
  13. 　請求項１２に記載のパワーモジュールの製造方法において、
    　前記セラミックス絶縁板の一方の面に配置される炭素成型体は凹部を有し、
    　前記第一の工程では当該凹部に前記セラミックス絶縁板が配置されることを特徴とするパワーモジュールの製造方法。     In the manufacturing method of the power module of Claim 12,
    The carbon molded body disposed on one surface of the ceramic insulating plate has a recess,
    In the first step, the ceramic insulating plate is disposed in the concave portion.
  14. 　請求項１２に記載のパワーモジュールの製造方法において、
    　前記セラミックス絶縁板の一方の面に配置される炭素成型体は凹部を有し、
    　前記第一の工程では、前記炭素成型体の凹部が形成された面とは反対側の面に前記セラミックス絶縁板が配置されることを特徴とするパワーモジュールの製造方法。     In the manufacturing method of the power module of Claim 12,
    The carbon molded body disposed on one surface of the ceramic insulating plate has a recess,
    In the first step, the ceramic insulating plate is disposed on a surface opposite to the surface on which the concave portion of the carbon molded body is formed.
  15. 　請求項１２に記載のパワーモジュールの製造方法において、
    　前記セラミックス絶縁板の一方の面に配置される炭素成型体には穴が設けられ、
    　前記第一の工程では、前記炭素成型体の穴と前記セラミックス絶縁板の隅部が対向するように配置されることを特徴とするパワーモジュールの製造方法。     In the manufacturing method of the power module of Claim 12,
    A hole is provided in the carbon molded body disposed on one surface of the ceramic insulating plate,
    In the first step, the method of manufacturing a power module, wherein the hole of the carbon molded body and the corner of the ceramic insulating plate are arranged to face each other.
  16. 　請求項１２に記載のパワーモジュールの製造方法において、
    　前記セラミックス絶縁板の一方の面に配置される炭素成型体は、一方の面よりも当該一方の面に対向する他方の面の方が小さい逆テーパー形状となるように構成され、
    　前記第一の工程では、前記炭素成型体の他方の面が前記セラミックス絶縁板と対向して配置されることを特徴とするパワーモジュールの製造方法。     In the manufacturing method of the power module of Claim 12,
    The carbon molded body disposed on one surface of the ceramic insulating plate is configured such that the other surface facing the one surface is smaller in reverse taper shape than the one surface,
    In the first step, the other surface of the carbon molded body is disposed so as to face the ceramic insulating plate.
PCT/JP2013/061562 2013-04-19 2013-04-19 Power module and manufacturing method therefor WO2014170997A1 (en)

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Citations (4)

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JPH0948677A (en) * 1995-08-04 1997-02-18 Dowa Mining Co Ltd Metal-ceramic composite substrate and its production
JP2007073875A (en) * 2005-09-09 2007-03-22 Ngk Insulators Ltd Heat spreader module and its manufacturing method
WO2008123172A1 (en) * 2007-03-27 2008-10-16 Ngk Insulators, Ltd. Heat spreader module, heat sink and method for manufacturing the heat spreader module and the heat sink
JP2010077013A (en) * 2008-08-29 2010-04-08 Kyocera Corp Carbon-metal composite and circuit member or heat radiation member using the same

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CN101361184B (en) * 2006-01-13 2011-04-13 电气化学工业株式会社 Aluminum/silicon carbide composite and heat radiation part making use of the same
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JPH0948677A (en) * 1995-08-04 1997-02-18 Dowa Mining Co Ltd Metal-ceramic composite substrate and its production
JP2007073875A (en) * 2005-09-09 2007-03-22 Ngk Insulators Ltd Heat spreader module and its manufacturing method
WO2008123172A1 (en) * 2007-03-27 2008-10-16 Ngk Insulators, Ltd. Heat spreader module, heat sink and method for manufacturing the heat spreader module and the heat sink
JP2010077013A (en) * 2008-08-29 2010-04-08 Kyocera Corp Carbon-metal composite and circuit member or heat radiation member using the same

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