WO2018061517A1 - Power module, method for producing same and electric power converter - Google Patents

Power module, method for producing same and electric power converter Download PDF

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Publication number
WO2018061517A1
WO2018061517A1 PCT/JP2017/029727 JP2017029727W WO2018061517A1 WO 2018061517 A1 WO2018061517 A1 WO 2018061517A1 JP 2017029727 W JP2017029727 W JP 2017029727W WO 2018061517 A1 WO2018061517 A1 WO 2018061517A1
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WO
WIPO (PCT)
Prior art keywords
power module
conductor layer
cooler
circuit board
module according
Prior art date
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PCT/JP2017/029727
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French (fr)
Japanese (ja)
Inventor
畑中　康道
真之介 曽田
昌樹 田屋
穂隆 六分一
平松　星紀
祥 小杉
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三菱電機株式会社
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Publication of WO2018061517A1 publication Critical patent/WO2018061517A1/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
    • H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
    • H01L23/29—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the material, e.g. carbon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/28—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection
    • H01L23/31—Encapsulations, e.g. encapsulating layers, coatings, e.g. for protection characterised by the arrangement or shape
    • 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
    • H01L23/46—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements involving the transfer of heat by flowing fluids
    • H01L23/473—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements involving the transfer of heat by flowing fluids by flowing liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L25/00—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof
    • H01L25/03—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes
    • H01L25/04—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers
    • H01L25/07—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers the devices being of a type provided for in group H01L29/00
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L25/00—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof
    • H01L25/18—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof the devices being of types provided for in two or more different subgroups of the same main group of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N
    • 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
    • H01L2224/33—Structure, shape, material or disposition of the layer connectors after the connecting process of a plurality of layer connectors
    • 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
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/181—Encapsulation

Definitions

  • the present invention relates to a molded resin-encapsulated power module provided with a cooler, a manufacturing method thereof, and a power conversion device provided with the power module.
  • an active element soldered to a conductor in contact with one surface of a ceramic substrate is sealed with a mold resin, and has a conductor film formed on the other surface of the ceramic substrate.
  • a power module is disclosed in which the peripheral portion of the surface of the ceramic substrate on which the conductor film is formed is covered and the conductor film and the cooler are joined (for example, Patent Document 1).
  • the difference in the thermal expansion coefficient between the power module and the cooler is large at the metal joint portion between the conductor layer exposed portion of the ceramic substrate and the cooler of the power module in which the ceramic substrate is sealed with mold resin.
  • peeling occurs at the metal joint due to thermal stress such as temperature cycle.
  • the present invention has been made to solve the above-described problems, and an object thereof is to obtain a power module in which the reliability of a metal joint portion between an insulating circuit board sealed with a mold resin and a cooler is improved. Yes.
  • the power module according to the present invention has a conductor layer on an upper surface and a lower surface, an insulating substrate on which a semiconductor element is mounted on the upper conductor layer, and the lower conductor layer has a flat portion on a lower side and a side portion on a side surface. And a sealing resin that seals the insulating substrate by exposing the flat surface portion and a part of the side surface portion, and a bonding material that bonds the flat surface portion exposed from the sealing resin and a part of the side surface portion. And a cooler bonded to the insulating substrate through a bonding material.
  • FIG. 1 is a schematic plan view showing a power module according to Embodiment 1 of the present invention.
  • FIG. 2 is a schematic cross-sectional structure diagram showing the power module according to Embodiment 1 of the present invention.
  • FIG. 2 is a schematic diagram of a cross-sectional structure taken along one-dot chain line AA in FIG.
  • a power module 100 includes an insulating circuit board 4, a semiconductor element 5, an electrode terminal 6, a molding resin 7 that is a sealing resin, a bonding material 8, and a cooler 9.
  • the insulated circuit board 4 includes a ceramic plate 1 that is an insulated substrate and conductor layers 2 and 3 formed on the upper and lower surfaces of the ceramic plate 1.
  • a ceramic plate 1 silicon nitride (Si 3 N 4 ), aluminum nitride (AlN), alumina, or Zr-containing alumina can be used.
  • AlN and Si 3 N 4 are preferable from the viewpoint of thermal conductivity, and Si 3 N 4 is more preferable from the viewpoint of material strength.
  • the conductor layers 2 and 3 formed on both surfaces (upper surface and lower surface) of the ceramic plate 1 are made of metal having the same dimensions (size) and thickness. However, since an electric circuit is formed on each of the conductor layers 2 and 3, the pattern shape may be different.
  • the conductor layers 2 and 3 are smaller than the ceramic plate 1. By making the size of the conductor layers 2 and 3 smaller than that of the ceramic plate 1, the creeping distance between the conductor layers 2 and 3 can be increased (secured). Further, by making the size of the conductor layer 3 smaller than that of the ceramic plate 1, the sealing resin 7 can be made to wrap around the ceramic plate 1.
  • metals having excellent electrical conductivity and thermal conductivity for example, aluminum and aluminum alloys, copper and copper alloys can be used. In particular, it is preferable to use copper from the viewpoints of heat conduction and electric conduction.
  • the semiconductor element 5 On the conductor layer 2 on the upper surface side of the ceramic plate 1, the semiconductor element 5 is electrically joined, for example, as a joining material 8 via solder.
  • a power control semiconductor element switching element
  • MOSFET Metal Oxide Semiconductor Field Effect Transistor
  • silicon carbide SiC
  • Si silicon carbide
  • SiC silicon carbide
  • Si semiconductor elements or SiC semiconductor elements using these as substrate materials are applied.
  • the thickness of the SiC semiconductor element is preferably 0.08 to 0.2 mm. In order to reduce the thickness of the SiC semiconductor element to less than 0.08 mm, it takes time and cost to grind a very hard SiC wafer. Further, when the thickness of the SiC semiconductor element is larger than 0.2 mm, the heat dissipation of the SiC semiconductor element is lowered and the thermal stress at the interface with the sealing resin is increased. Therefore, the thickness of the SiC semiconductor element is preferably in the range of 0.08 to 0.2 mm.
  • solder is usually used as the bonding material 8 for bonding the semiconductor element 5 and the conductor layer 2 on the upper surface side of the insulating circuit board 4.
  • the bonding material 8 may be sintered silver or a liquid phase diffusion material. Sintered silver or a liquid phase diffusion material has a melting temperature higher than that of a solder material, and does not remelt when the cooler 9 and the conductor layer 3 on the lower surface side of the insulated circuit board 4 are joined. And the bonding reliability of the insulating circuit board 4 is improved.
  • the operating temperature of the power module 100 can be increased. Since sintered silver has better thermal conductivity than solder, the heat dissipation of the semiconductor element 5 is improved and the reliability is improved. Since the liquid phase diffusion material can be bonded with a lower load than sintered silver, the processability is good, and the influence of damage to the semiconductor element 5 due to the bonding load can be prevented.
  • the electrode terminal 6 is bonded to a predetermined electrode terminal 6 bonding position on the semiconductor element 5.
  • the electrode terminal 6 is also bonded to a predetermined electrode terminal 6 bonding position on the conductor layer 2 on the upper surface side of the insulated circuit board 4.
  • the electrode terminal 6 has a structure protruding from the side surface of the mold resin 7 to the outside.
  • a copper plate having a thickness of 0.5 mm processed into a predetermined shape by etching or die punching can be used as the electrode terminal 6, for example.
  • the conductor layer 3 on the lower surface side of the insulated circuit board 4 to which the semiconductor element 5 is not bonded includes a flat surface portion 31 on the lower side opposite to the surface in contact with the ceramic plate 1 and a side surface portion 32 on the side surface.
  • the conductor layer 3 is sealed with the mold resin 7 so that the lower flat portion 31 and a part of the side portion 32 on the side surface are exposed.
  • the exposed flat portion 31 and part of the side surface portion 32 of the conductor layer 3 are bonded to the cooler 9 using the bonding material 8.
  • the bonding material 8 is formed not only on the flat surface portion 31 of the conductor layer 3 but also on a part of the side surface portion 32 of the conductor layer 3.
  • the bonding material 8 is formed to a position (height) that contacts the portion of the mold resin 7 on the cooler 9 side (the bottom portion of the mold resin 7). However, as a position where the bonding material 8 is formed, the bonding material 8 may come into contact (climb up) on the mold resin 7, and the side surface portion 32 may be formed without contact between the mold resin 7 and the bonding material 8. It may be formed away from the top.
  • Mold resin 7 seals a part of insulating substrate 1, conductor layer 2, and side surface portion 32 of conductor layer 3 described above.
  • the mold resin 7 for example, an epoxy resin / phenol resin curing agent type mold resin filled with silica particles can be used.
  • solder can be used as the bonding material 8 between the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the cooler 9.
  • solder a Sn—Sb composition type solder material is preferable from the viewpoint of bonding reliability.
  • sintered silver or a liquid phase diffusion material is applied in addition to the solder as in the case of joining the semiconductor element 5 and the insulated circuit board 4. Is possible.
  • the solder shape of the junction part of the side part 32 of the conductor layer 3 and the cooler 9 becomes a taper (fillet) shape which gave the inclination.
  • the taper shape of the solder which is the bonding material 8 is a shape that expands from the insulating substrate 1 side of the side surface portion 32 of the conductor layer 3 toward the outer peripheral side of the cooler 9 (bottoming). That is, the solder shape of the joint portion between the side surface portion 32 of the conductor layer 3 and the cooler 9 is a shape in which the width on the cooler 9 side is wider than the width on the insulating substrate 1 side in a sectional view.
  • liquid phase diffusion material a Cu—Sn composition system material or a Cu—Ag composition system material is preferable from the viewpoint of bonding reliability. Since sintered silver has better thermal conductivity than solder, the heat dissipation of the power module 100 is improved and the reliability is improved. In addition, since the liquid phase diffusion material can be bonded with a lower load than sintered silver, the processability is good, and the influence of damage to the power module 100 due to the bonding load can be prevented.
  • the cooler 9 can be made of, for example, a composite material made of aluminum and ceramics such as aluminum and aluminum alloy, copper and copper alloy, and AlSiC. In particular, aluminum and aluminum alloys are preferable from the viewpoints of thermal conductivity, workability, and light weight. Inside the cooler 9, a flow path for flowing a cooling refrigerant is formed. In FIG. 2, it is possible to cool more efficiently by providing a plurality of cooling pins 91.
  • the structure of the cooler 9 is not limited to this structure, and any structure that can be cooled is applicable.
  • FIGS. 3 to 11 are schematic cross-sectional views showing the manufacturing steps of the power module according to Embodiment 1 of the present invention.
  • FIG. 3 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention.
  • FIG. 4 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module in the first embodiment of the present invention.
  • FIG. 5 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention.
  • FIG. 6 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention.
  • FIG. 3 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention.
  • FIG. 7 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module according to Embodiment 1 of the present invention.
  • FIG. 8 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention.
  • FIG. 9 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention.
  • FIG. 10 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module according to Embodiment 1 of the present invention.
  • FIG. 11 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module in the first embodiment of the present invention.
  • the power module 100 can be manufactured through the steps of FIGS.
  • the conductor layer 2 is formed on the upper surface of the ceramic plate 1, and the conductor layer 3 is formed on the lower surface (insulating circuit board forming step).
  • the ceramic plate 1 and the conductor layers 2 and 3 are joined by brazing or the like.
  • the conductor layers 2 and 3 are formed using metal layers having the same size and thickness.
  • the formation positions of the conductor layers 2 and 3 on the ceramic plate 1 are symmetrical (same) positions with the ceramic plate 1 interposed therebetween.
  • the pattern shape may be different.
  • the conductor layer 3 has a flat surface portion 31 opposite to the surface of the conductor layer 3 on the lower surface side of the insulated circuit board 4 that is in contact with the ceramic plate 1 and a side surface portion 32 of the conductor layer 3.
  • the semiconductor element 5 and the electrode terminal 6 are placed at predetermined positions (semiconductor element 5 arrangement region or electrode terminal 6 arrangement region) on the conductor layer 2 on the upper surface of the insulating circuit substrate 4. It electrically joins using the solder which is the joining material 8.
  • the electrode terminal 6 is electrically bonded to a predetermined position on the semiconductor element 5 (electrode terminal 6 arrangement region) using solder which is the bonding material 8 (member bonding step).
  • an electrical circuit is formed by joining the semiconductor element 5 and the electrode terminal 6 on the insulating circuit substrate 4.
  • the insulated circuit board 4 produced in the previous step is fixed in a mold processed into a predetermined shape and sealed with a mold resin 7.
  • the insulating circuit board 4 is placed on the lower mold 12, the upper mold 11 is placed on the lower mold 12, the mold resin 7 is press-fitted, and the press-fitted mold resin 7 is cured. I do.
  • the lower mold 12 is prepared (lower mold installation step), and the conductor layer 3 of the insulated circuit board 4 in which the semiconductor element 5 and the electrode terminal 6 are joined on the conductor layer 2 is formed in the lower mold. 12 is inserted into the lower mold cavity 13 which is an inset portion formed in the insulating portion 12 (insulating circuit board installation step).
  • the lower mold cavity 13 includes a lower flat portion 31 on the opposite side of the surface of the conductor layer 3 on the lower surface side of the insulating circuit board 4 that is in contact with the ceramic plate 1 and a side portion 32 on the side surface of the conductor layer 3. It is for fitting the part.
  • the portion of the conductor layer 3 (a part of the flat surface portion 31 and the side surface portion 32) fitted in the lower mold cavity 13 is not sealed with the mold resin 7 after the resin sealing, and is exposed from the mold resin 7. It becomes an area. Further, the portion exposed from the lower mold cavity 13 of the conductor layer 3 is sealed with a mold resin 7 after sealing with resin.
  • the lower mold 12 and the upper mold 11 are combined and the upper and lower molds are closed to dispose the insulating circuit board 4 inside the upper mold 11 and the lower mold 12.
  • the upper mold 11 and the lower mold 12 are fixed in a state where a part of the electrode terminal 6 protrudes from the side surface of the mold (upper mold installation step).
  • the electrode terminal 6 can be exposed to the outside of the mold resin 7 after sealing with the mold resin 7.
  • the electrode terminal 6 may be configured to have a bent portion in accordance with a protruding position from the mold resin 7 (not shown).
  • a mold resin 7 is press-fitted into a mold in which the insulating circuit board 4 is disposed.
  • a state in which the mold resin 7 is being press-fitted from the right side to the left side indicated by an arrow is shown.
  • the mold resin 7 for example, an epoxy resin / phenol resin curing agent resin (thermal expansion coefficient 12 ppm / K) filled with silica particles can be used (resin sealing step). Moreover, it can seal with the mold resin 7 by pressing-in the mold resin 7 in a metal mold
  • the mold resin 7 that has been press-fitted in the state where the insulating circuit board 4 is disposed in the mold is cured.
  • the curing treatment condition for the mold resin 7 is performed at 180 ° C. for 3 minutes (first resin curing step).
  • the press-fitted mold resin 7 is cured by performing the curing process.
  • the insulating circuit board 4 that has been sealed with the mold resin 7 is taken out from the upper and lower molds (insulating circuit board removing step).
  • the mold resin 7 is in a state in which the entire upper surface side of the insulating circuit substrate 4 and a part of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit substrate 4 are sealed.
  • the planar portion 31 and part of the side surface portion 32 of the conductor layer 3 are exposed from the mold resin 7.
  • the position of the mold resin 7 on the side surface portion 32 of the conductor layer 3 is such that when the insulating circuit board 4 is placed on the lower mold 12, the amount of insertion (depth) of the lower mold cavity 13 in which the conductor layer 3 is installed. Determined by.
  • the depth of the lower mold cavity 13 determines the exposure amount of the side surface portion 32 of the conductor layer 3 from the mold resin 7. Then, by adjusting the depth of the lower mold cavity 13, desired characteristics (peeling characteristics, insulating characteristics) can be obtained.
  • the insulating circuit board 4 sealed with the mold resin 7 taken out from the upper and lower molds shown in FIG. 9 is subjected to a curing treatment of the mold resin 7 in an oven at 175 ° C. for 6 hours (second process). Resin curing step). Through these steps, the insulated circuit board 4 sealed with the mold resin 7 is completed.
  • the insulating circuit board 4 resin-sealed with the mold resin 7 is fixed to a predetermined position of the cooler 9 with a jig through the bonding material 8 (cooling).
  • Container placement step ).
  • the bonding material 8 is melted and exposed from the mold resin 7 by reflowing the bonding material 8 using a reflow furnace as shown in FIG. 11.
  • the plane portion 31 and part of the side surface portion 32 (exposed portion) of the conductor layer 3 on the lower surface side of the insulated circuit board 4 are bonded to the cooler 9 via the bonding material 8 (cooler bonding step).
  • the power module 100 can be manufactured through the above main manufacturing processes.
  • the basic structure of the power module 100 used for the evaluation is as follows.
  • a Si semiconductor element As the semiconductor element 5, a Si semiconductor element is used. Then, a 0.1 mm-thick Si semiconductor element is joined to a predetermined position of the insulated circuit board 4 having an outer shape of 20 mm ⁇ 20 mm with solder. Then, the electrode terminal 6 is soldered to a predetermined position of the insulating circuit board 4 and the Si semiconductor element.
  • the copper pattern is formed is a conductive layer 2 and 3 of 16 mm ⁇ 16 mm in thickness 0.7mm size on both surfaces of the ceramic plate 1 of a thickness of 0.32 mm Si 3 N 4 ing.
  • the size of the conductor layers 2 and 3 is smaller than the size of the ceramic plate 1, and the conductor layers 2 and 3 do not protrude from the ceramic plate 1.
  • the lower mold 12 used for transfer mold sealing is fitted with the flat portion 31 and part of the side portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit board 4 having a size of 16 mm ⁇ 16 mm and a depth of 0.5 mm.
  • a lower mold cavity 13 is formed. For this reason, the entire surface of the ceramic plate 1 of the insulating circuit board 4 is sealed with the mold resin 7, and the plane of the lower planar portion 31 and the side portion 32 formed on the lower surface of the conductor layer 3 formed on the ceramic plate 1.
  • a height of 0.5 mm is exposed from the surface of the portion 31 toward the ceramic plate 1 and is sealed with a mold resin 7 (from the ceramic plate 1 of the side surface portion 32 of the conductor layer 3 to a position of 0.2 mm downward) Was sealed with mold resin 7).
  • a film-like solder having a size of 16 mm ⁇ 16 mm and a thickness of 0.3 mm is used as the bonding material 8. Then, the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the film-like solder were fixed to a predetermined position of the cooler 9 with a jig, and joined by heating in a reflow furnace.
  • the solder is inserted into the lower mold cavity 13 of the lower mold 12 of the conductor layer 3 on the lower surface side of the insulated circuit board 4. It joins with the part (a part of plane part 31 and side part 32) exposed from mold resin 7 which had been.
  • the cooler 9 is made of aluminum, and has a size of 60 mm ⁇ 60 mm and a thickness of 15 mm, and is capable of joining six insulated circuit boards 4 having a size of 20 mm ⁇ 20 mm.
  • the solder thickness between the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 is 0.25 mm. It is adjusted. Therefore, the solder protrudes from the exposed flat surface portion 31 of the conductor layer 3 on the lower surface side of the insulated circuit board 4 and is formed along the 0.5 mm exposed portion of the side surface portion 32 of the lower surface side conductor layer 3.
  • the solder shape formed on the side surface portion 32 of the conductor layer 3 is a taper shape from the ceramic plate 1 side toward the cooler 9, and a skirt (fillet) extending toward the outer peripheral portion of the cooler 9 on the upper surface of the cooler 9. Shape. That is, the solder shape of the joint portion between the side surface portion 32 of the conductor layer 3 and the cooler 9 is a shape in which the width on the cooler 9 side is wider than the width on the insulating substrate 1 side in a sectional view.
  • the solder thickness between the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 is adjusted by forming a 0.25 mm bonding wire spacer on the surface (upper surface) of the cooler 9 with a wire bonder.
  • the thickness was controlled to be 0.25 mm.
  • FIG. 12 is a schematic cross-sectional structure diagram showing the end portion of the insulating substrate of the power module according to Embodiment 1 of the present invention.
  • the thickness of the conductor layer 3 on the lower surface side of the insulated circuit board 4 is t (mm)
  • the exposed length of the conductor layer 3 was L (mm).
  • Table 1 shows the specifications of the prototype power module, the temperature cycle test peeling determination result, and the insulation test determination result.
  • Evaluation sample examples 1 to 18 differ only in the thickness (t) of the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the exposed length (L) from the mold resin 7 on the side surface portion 32 of the conductor layer 3.
  • a power module was prototyped by the same method as described above.
  • the exposed length of the side surface portion 32 of the conductor layer 3 from the mold resin 7 is determined by the depth of the lower mold cavity 13.
  • Table 1 shows the evaluation results as “OK” when no peeling was observed after the temperature cycle, and “NG” when peeling was observed.
  • FIG. 13 is a relationship diagram between the conductor layer thickness and the conductor layer side surface exposed length of the power module according to Embodiment 1 of the present invention.
  • Table 1 shows the conditions for which the determination was “OK” in both the peel determination and the insulation test determination after the temperature cycle test.
  • “black circles” in the graph indicate the exposed length L of the side surface portion 32 of the conductor layer 3 that becomes a pass determination in the temperature cycle test determination at each thickness t of the conductor layer 3.
  • the region of the exposure length L below the “black circle” is a region that fails the temperature cycle test determination, and the region of the exposure length L above the “black circle” passes the temperature cycle test determination. It is an area. It has been found that the exposed length L of the side surface portion 32 of the conductor layer 3 that is determined to pass in the temperature cycle test has a correlation with the thickness t of the conductor layer 3 and is shown below.
  • the exposed length L of the side surface portion 32 of the conductor layer 3 is the taper (fillet) height of the solder.
  • the exposed length L of the side surface portion 32 of the conductor layer 3 has an appropriate region with respect to the thickness t of the conductor layer 3.
  • Black squares in the graph of FIG. 13 indicate the exposed length L of the side surface portion 32 of the conductor layer 3 that is determined to pass in the insulation test at each thickness t of the conductor layer 3.
  • the region of the exposure length L below the “black square” is a region that passes the insulation test determination, and the region of the exposure length L above the “black square” is a region that fails the insulation test determination. It is. It has been found that the exposed length L of the side surface portion 32 of the conductor layer, which is determined to pass in the insulation test, has a correlation with the conductor layer thickness t and is shown below.
  • the dielectric breakdown path of the power module 100 is based on the ceramic plate 1 and the mold resin 7 starting from the end of the conductor layer 2 on the upper surface side of the insulated circuit board 4 on which the semiconductor element 5 having the maximum electric field strength is mounted. From the interface to the cooler 9.
  • the withstand voltage is greatly improved as compared with the case where the insulating circuit board 4 is not sealed with the mold resin 7.
  • the insulating properties are deteriorated because it approaches a state where the mold resin 7 is not sealed.
  • the difference between the thickness t of the conductor layer 3 and the exposed length L of the side surface portion 32 of the conductor layer 3 is adhered to the lower surface side of the ceramic plate 1 of the insulating circuit substrate 4 (the lower surface side is sealed). ) The thickness of the mold resin 7 is obtained.
  • the gap between the ceramic plate 1 and the mold is narrow at the time of molding the mold resin 7 and sufficient injection (intrusion) of the mold resin 7 is performed. Peeling and voids are generated between the ceramic plate 1 and the mold resin 7.
  • the resin thickness of the mold resin 7 adhered to the lower surface side of the ceramic plate 1 of the insulating circuit board 4 has a lower limit value, and the thickness is required to be 0.2 mm or more.
  • the exposed length L of the side surface portion 32 of the conductor layer 3 has an appropriate value. It was found that the formula (3) needs to be satisfied. Moreover, when the thickness of the conductor layer 3 was 0.4 mm, there was no area
  • the thickness of the conductor layer 3 increases, the area where both the bonding reliability between the insulating circuit board 4 and the cooler 9 and the insulation reliability of the power module 100 can be secured increases.
  • the upper limit of the thickness of the conductor layer 3 is also restricted due to restrictions in manufacturing the insulated circuit board 4 and restrictions on the temperature cycle test resistance of the insulated circuit board 4 itself.
  • the etching time is increased in proportion to the thickness of the conductor layer 3 and the manufacturing cost is increased.
  • the conductor layer 3 is thickened, thermal stress increases at the interface between the ceramic plate 1 and the conductor layer 3, and cracking of the ceramic plate 1 occurs even in a temperature cycle test with the insulated circuit board 4 alone. For this reason, the upper limit of the thickness of the conductor layer 3 is 1.0 mm.
  • FIG. 14 is a schematic cross-sectional view showing another power module according to Embodiment 1 of the present invention.
  • the power module 200 includes an insulated circuit board 4 sealed with two mold resins 7 on a cooler 9. In this way, by adjusting the size of the cooler 9, it is possible to arrange the insulated circuit board 4 sealed with a plurality of mold resins 7.
  • a part of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit substrate 4 sealed with the mold resin 7 is sealed with the mold resin 7. Since the planar portion 31 and part of the side surface portion 32 of the conductor layer 3 exposed from above and the cooler 9 are joined by the joining material 8, the occurrence of peeling at the metal joining portion can be suppressed. As a result, it becomes possible to improve the reliability of the power module.
  • the shape of the joined portion obtained by joining a part of the side surface portion 32 of the conductor layer 3 exposed from the mold resin 7 and the cooler 9 with the joining material 8 is a taper (fillet) shape, the heat at the metal joined portion The generation of stress can be suppressed, and the reliability of the power module can be improved.
  • the solder resist 10 is formed on the upper surface of the cooler 9 when the conductor layer 3 on the lower surface side of the insulated circuit board 4 used in the first embodiment and the cooler 9 are joined.
  • the solder resist 10 is formed on the upper surface of the cooler 9, the flow region of the bonding material 8 at the time of bonding between the conductor layer 3 and the cooler 9 can be restricted, and the side surface of the conductor layer 3 is surely The exposed region of the portion 32 can be covered with the bonding material 8. As a result, it becomes possible to improve the reliability of the power module. Since other points are the same as those in the first embodiment, detailed description thereof is omitted.
  • FIG. 15 is a schematic plan view showing the power module according to Embodiment 2 of the present invention.
  • FIG. 16 is a schematic cross-sectional structure diagram showing a power module according to Embodiment 2 of the present invention.
  • FIG. 16 is a schematic diagram of a cross-sectional structure taken along one-dot chain line BB in FIG.
  • a power module 300 includes an insulating circuit board 4, a semiconductor element 5, an electrode terminal 6, a molding resin 7 as a sealing resin, a bonding material 8, a cooler 9, and a solder resist 10. Except that the solder resist 10 is formed, it is the same as the first embodiment.
  • the solder resist 10 is formed on a surface where the conductor layer 3 on the lower surface side of the insulating circuit board 4 which is the upper surface of the cooler 9 is bonded by the bonding material 8.
  • the solder resist 10 is provided in a region surrounding the outer periphery of the bonding material 8 on the upper surface of the cooler 9. At this time, the solder resist 10 is formed with a predetermined distance from the bonding material 8. Therefore, the solder resist 10 has an opening 101 in the central region so that the bonding material 8 can be arranged at a predetermined interval.
  • the purpose of the solder resist 10 is arranged to limit the region where the bonding material 8 spreads on the upper surface of the cooler 9. That is, the solder resist 10 is disposed at a position where the bonding material 8 formed on the side surface portion 32 of the conductor layer 3 can be accurately tapered.
  • solder resist 10 As the solder resist 10, a general commercial product can be applied as long as adhesion to the cooler 9 and heat resistance can be secured.
  • FIG. 17 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module in the second embodiment of the present invention.
  • FIG. 18 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module in the second embodiment of the present invention.
  • FIG. 19 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module according to Embodiment 2 of the present invention.
  • FIG. 17 is performed after the manufacturing process of FIG. 9, and FIGS. 18 and 19 are replaced with the manufacturing process shown in FIGS.
  • the power module 300 using 10 can be manufactured.
  • solder resist 10 is formed on the outer peripheral portion of the upper surface of the cooler 9 as shown in FIG. 17. (Solder resist forming step). At this time, the solder resist 10 is formed with the opening 101 in the central region of the upper surface of the cooler 9.
  • the bonding material 8 is disposed in the opening 101 surrounded by the solder resist 10. Then, the insulating circuit board 4 encapsulated with the mold resin 7 is bonded to a predetermined position in the central region of the upper surface of the cooler 9 whose outer periphery is covered with the solder resist 10 via the bonding material 8. It is fixed using (cooler arrangement process).
  • the bonding material 8 is reflowed using a reflow furnace as shown in FIG. 19 instead of FIG. As a result, the bonding material 8 is melted, and the flat portion 31 and the portion (exposed portion) of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit substrate 4 exposed from the mold resin 7 are bonded to the cooler 9. (Cooler joining process).
  • the bonding material 8 has the solder resist 10 disposed on the outer peripheral portion of the upper surface of the cooler 9, so that the range (region) that is expanded during reflow is limited. That is, it expands inside the opening 101 of the solder resist 10. Due to the solder resist 10, the bonding material 8 is restricted in diffusion and gathers at the peripheral corners of the conductor layer 3, so that the exposed portion of the side surface portion 32 of the conductor layer 3 can be reliably covered.
  • the bonding material 8 is sufficiently supplied also at the corners of the conductor layer 3. Therefore, it becomes easy to form the taper (fillet) shape of the bonding material 8 also in this corner portion.
  • FIG. 20 is a schematic plan view showing the solder resist shape of the power module according to Embodiment 2 of the present invention.
  • FIG. 21 is a schematic cross-sectional structure diagram showing a corner portion of the power module according to Embodiment 2 of the present invention.
  • the conductor layer 3 is indicated by a dotted line.
  • the solder resist 10 has a dimension of 21 mm on the inner side and an opening in the central region.
  • the distance between the side portion of the conductor layer 3 and the side portion of the solder resist 10 is 2.5 mm.
  • a film-like solder having a size of 16 mm ⁇ 16 mm and a thickness of 0.3 mm is used as the bonding material 8 as in the first embodiment. It was implemented by fixing the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the film-like solder to a predetermined position of the cooler 9 with a jig and heating.
  • the solder thickness between the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 is adjusted to be 0.25 mm. Therefore, the solder protrudes from the exposed flat portion 31 of the conductor layer 3 on the lower surface side of the insulated circuit board 4, and a taper of the solder is formed along the exposed portion of the side surface portion 32 of the conductor layer 3 by 0.5 mm. It was.
  • FIG. 21 the result of having observed the taper shape of the corner
  • a portion of the conductor layer 3 covered with the mold resin 7 or the bonding material 8 is indicated by a dotted line.
  • the solder resist 10 When the solder resist 10 is not formed, the spread of the solder cannot be regulated, so that the amount of solder supplied to the corner of the conductor layer 3 is small and the taper height at the corner tends to be low. However, since the solder resist 10 is formed, the solder resist 10 acts as a dam with respect to the solder, and the solder spreads in a substantially square shape. As a result, since the solder also wraps around the exposed corners of the conductor layer 3, it is possible to ensure a taper height. And the reliability of the power module 300 improves.
  • FIG. 22 is a schematic plan view showing another solder resist shape of the power module according to Embodiment 2 of the present invention.
  • FIG. 23 is a schematic plan view showing another solder resist shape of the power module according to Embodiment 2 of the present invention.
  • FIG. 24 is a schematic cross-sectional structure diagram showing another corner portion of the power module according to Embodiment 2 of the present invention.
  • the conductor layer 3 is indicated by a dotted line.
  • the solder resist 10 has an inner side dimension of 18 mm and an opening in the central region.
  • a projecting portion pointed from the inside to the outside in which the opening from the inside toward the outside widens.
  • the distance between the side portion of the conductor layer 3 and the side portion of the solder resist 10 is 1.0 mm.
  • the shape of the protruding portion of the solder resist 10 is not limited to a shape with a sharp tip as shown in FIG. 22, but may have a round shape (a shape with a curvature) as shown in FIG. .
  • the solder is formed in the shape of the opening of the solder resist 10. For this reason, by making the tip of the protruding portion of the opening of the solder resist 10 round, it is possible to relieve the thermal stress acting on the solder during the temperature cycle test, and the reliability of the power module 300 is improved.
  • the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the cooler 9 are joined using film-like solder having a size of 16 mm ⁇ 16 mm and a thickness of 0.3 mm.
  • the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the film-like solder were fixed with a jig at a predetermined position of the cooler 9 and heated.
  • the solder thickness between the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 is adjusted to be 0.25 mm. Therefore, the solder protrudes outward from the exposed flat portion 31 of the conductor layer 3 on the lower surface side of the insulated circuit board 4, and forms a taper of the solder along the exposed portion of the side surface portion 32 of the conductor layer 3 by 0.5 mm. It became.
  • FIG. 24 shows the result of observing the tapered shape of the corner (corner portion) of the exposed conductor layer 3 after joining the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9.
  • a portion of the conductor layer 3 covered with the mold resin 7 or the bonding material 8 is indicated by a dotted line.
  • the solder also wraps around the exposed corner of the conductor layer 3. Further, as shown in FIG. 22 and FIG. 23, in the vicinity of the inner corner of the solder resist 10, since the protrusion is provided, the solder further wraps around the protrusion, and the uniform height. Can be formed. That is, the height of the solder in the side surface portion 32 of the conductor layer 3 is formed high (closer to the lower surface side of the insulating substrate 1 on which the conductor layer 3 is formed). Therefore, since the taper height of the conductor layer corner portion where the thermal stress is maximized during the temperature cycle test is secured, it is possible to prevent the peeling of the solder due to the stress relaxation effect of the taper, and the reliability of the power module 300 is improved.
  • the opening shape of the solder resist 10 be a shape approximately 1.0 mm larger than the outer shape of the conductor layer 3.
  • FIG. 25 is a schematic plan view showing another power module according to Embodiment 2 of the present invention.
  • a power module 400 includes an insulated circuit board 4 sealed with two mold resins 7 on a cooler 9.
  • a solder resist 10 is formed on the outer periphery of the conductor layer 3 on the lower surface side of each insulating circuit board 4. In this way, by adjusting the size of the cooler 9, it is possible to arrange the insulated circuit board 4 sealed with a plurality of mold resins 7.
  • a part of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit board 4 sealed with the mold resin 7 is also sealed with the mold resin 7. Since the planar portion 31, the side surface portion 32, and the cooler 9 of the conductor layer 3 exposed from the above are joined by the joining material 8, it is possible to suppress the occurrence of peeling at the metal joining portion. As a result, it becomes possible to improve the reliability of the power module.
  • the shape of the joint portion obtained by joining the flat portion 31, the side surface portion 32, and the cooler 9 of the conductor layer 3 exposed from the mold resin 7 with the joining material 8 is a tapered shape, the thermal stress at the metal joint portion is reduced. Generation
  • production can be suppressed and it becomes possible to improve the reliability of a power module.
  • solder resist 10 it is possible to form a tapered shape also at the corners of the conductor layer 3, to suppress the generation of thermal stress at the metal joint, and to improve the reliability of the power module. It becomes possible.
  • the shape of the solder resist 10 formed on the upper surface of the cooler 9 is a shape provided with a protruding portion in which the corner portion of the solder resist 10 protrudes from the inner side to the outer side, A taper shape with a uniform height can be formed, generation of thermal stress at the metal joint can be suppressed, and the reliability of the power module can be improved.
  • Embodiment 3 FIG.
  • the third embodiment is different in that the electrode terminal 6 used in the first and second embodiments is protruded from the upper surface side of the power module to the outside of the mold resin 7.
  • the electrode terminal 6 since the electrode terminal 6 is protruded from the upper surface side of the mold resin 7, the power module can be downsized while the reliability of the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the cooler 9 is ensured. It becomes possible. Since other points are the same as those in the first embodiment or the second embodiment, detailed description thereof is omitted.
  • FIG. 26 is a schematic plan view showing a power module according to Embodiment 3 of the present invention.
  • FIG. 27 is a schematic cross-sectional structure diagram showing a power module according to Embodiment 3 of the present invention.
  • FIG. 27 is a schematic cross-sectional view taken along the alternate long and short dash line CC in FIG.
  • a power module 500 includes an insulating circuit board 4, a semiconductor element 5, an electrode terminal 6, a mold resin 7, a bonding material 8, a cooler 9, and a solder resist 10.
  • the structure is the same as that of the second embodiment except that the electrode terminal 6 has a protruding structure protruding from the upper surface side of the mold resin 7 to the outside.
  • the mold resin sealing with the electrode terminal 6 protruding upward is performed by, for example, forming a cavity for storing the electrode terminal 6 in the upper mold, and inserting the electrode terminal 6 therein. And do it.
  • the electrode terminal 6 is processed into a predetermined shape.
  • the power module 500 can be manufactured in the same manner as in the second embodiment. Further, as in the first embodiment, a power module structure that does not use the solder resist 10 can be realized. With such a structure, the power module can be reduced in size while ensuring the reliability of the conductor layer 3 on the lower surface side of the insulated circuit board 4, the cooler 9, and the joint.
  • a part of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit board 4 sealed with the mold resin 7 is also sealed with the mold resin 7. Since the planar portion 31, the side surface portion 32, and the cooler 9 of the conductor layer 3 exposed from the above are joined by the joining material 8, it is possible to suppress the occurrence of peeling at the metal joining portion. As a result, it becomes possible to improve the reliability of the power module.
  • the shape of the joint portion obtained by joining the flat portion 31, the side surface portion 32, and the cooler 9 of the conductor layer 3 exposed from the mold resin 7 with the joining material 8 is a tapered shape, the thermal stress at the metal joint portion is reduced. Generation
  • production can be suppressed and it becomes possible to improve the reliability of a power module.
  • solder resist 10 it is possible to form a tapered shape also at the corners of the conductor layer 3, to suppress the generation of thermal stress at the metal joint, and to improve the reliability of the power module. It becomes possible.
  • the shape of the solder resist 10 formed on the upper surface of the cooler 9 is a shape in which the corner portion of the solder resist 10 protrudes to the outer peripheral side, a tapered shape having a uniform height at the corner portion of the conductor layer 3 is also formed. It can be formed, the generation of thermal stress at the metal joint can be suppressed, and the reliability of the power module can be improved.
  • the electrode terminal 6 is protruded from the upper surface side of the mold resin 7 to the outside of the mold resin 7, the power of the conductor layer 3 on the lower surface side of the insulated circuit board 4, the cooler 9, and the joint is ensured.
  • the module can be miniaturized.
  • Embodiment 4 the power module according to the first to third embodiments described above is applied to a power converter.
  • the present invention is not limited to a specific power converter, hereinafter, a case where the present invention is applied to a three-phase inverter will be described as a fourth embodiment.
  • FIG. 28 is a block diagram showing a configuration of a power conversion system to which the power conversion device according to Embodiment 4 of the present invention is applied.
  • the power supply 1000 is a DC power supply and supplies DC power to the power converter 2000.
  • the power supply 1000 can be composed of various types.
  • the power source 1000 can be composed of a direct current system, a solar battery, or a storage battery, and can be composed of a rectifier circuit or an AC / DC converter connected to the alternating current system. Also good.
  • the power supply 1000 may be configured by a DC / DC converter that converts DC power output from the DC system into predetermined power.
  • the power conversion device 2000 is a three-phase inverter connected between the power supply 1000 and the load 3000, converts DC power supplied from the power supply 1000 into AC power, and supplies AC power to the load 3000. As shown in FIG. 13, the power conversion device 2000 converts a DC power input from the power supply 1000 into an AC power and outputs a main conversion circuit 2001, and a control signal for controlling the main conversion circuit 2001. And a control circuit 2003 for outputting to the computer.
  • the load 3000 is a three-phase motor driven by AC power supplied from the power converter 2000.
  • the load 3000 is not limited to a specific application, and is an electric motor mounted on various electric devices.
  • the load 3000 is used as an electric motor for a hybrid vehicle, an electric vehicle, a railway vehicle, an elevator, or an air conditioner.
  • the main conversion circuit 2001 includes a switching element and a free wheel diode (not shown) built in the power module 2002, and converts the DC power supplied from the power supply 1000 into AC power by switching the switching element.
  • the load 3000 is supplied.
  • the main conversion circuit 2001 according to the present embodiment is a two-level three-phase full bridge circuit, and includes six switching elements and respective switching elements. It can be composed of six anti-parallel diodes.
  • the main conversion circuit 2001 is configured by a power module 2002 corresponding to any one of the above-described first to third embodiments, in which each switching element and each free-wheeling diode are incorporated.
  • the six switching elements are connected in series for each of the two switching elements to constitute upper and lower arms, and each upper and lower arm constitutes each phase (U phase, V phase, W phase) of the full bridge circuit.
  • the output terminals of the upper and lower arms that is, the three output terminals of the main conversion circuit 2001 are connected to the load 3000.
  • the main conversion circuit 2001 includes a drive circuit (not shown) for driving each switching element.
  • the drive circuit may be built in the power module 2002 or a drive circuit may be provided separately from the power module 2002. The structure provided may be sufficient.
  • the drive circuit generates a drive signal for driving the switching element of the main conversion circuit 2001 and supplies it to the control electrode of the switching element of the main conversion circuit 2001. Specifically, in accordance with a control signal from a control circuit 2003 described later, a drive signal for turning on the switching element and a drive signal for turning off the switching element are output to the control electrode of each switching element.
  • the drive signal When the switching element is maintained in the ON state, the drive signal is a voltage signal (ON signal) that is equal to or higher than the threshold voltage of the switching element, and when the switching element is maintained in the OFF state, the drive signal is a voltage that is equal to or lower than the threshold voltage of the switching element.
  • Signal (off signal) When the switching element is maintained in the ON state, the drive signal is a voltage signal (ON signal) that is equal to or higher than the threshold voltage of the switching element, and when the switching element is maintained in the OFF state, the drive signal is a voltage that is equal to or lower than the threshold voltage of the switching element.
  • Signal (off signal) When the switching element is maintained in the ON state, the drive signal is a voltage signal (ON signal) that is equal to or higher than the threshold voltage of the switching element, and when the switching element is maintained in the OFF state, the drive signal is a voltage that is equal to or lower than the threshold voltage of the switching element.
  • Signal (off signal) When the switching element is maintained in the ON state,
  • the control circuit 2003 controls the switching element of the main conversion circuit 2001 so that desired power is supplied to the load 3000. Specifically, based on the power to be supplied to the load 3000, the time (ON time) during which each switching element of the main converter circuit 2001 is to be turned on is calculated. For example, the main conversion circuit 2001 can be controlled by PWM control that modulates the ON time of the switching element according to the voltage to be output. Then, a control command (control signal) is supplied to the drive circuit included in the main conversion circuit 2001 so that an ON signal is output to the switching element that should be turned on at each time point and an OFF signal is output to the switching element that should be turned off. Is output. In accordance with this control signal, the drive circuit outputs an ON signal or an OFF signal as a drive signal to the control electrode of each switching element.
  • the power module according to the first to third embodiments is applied as the power module 2002 of the main conversion circuit 2001, thereby improving reliability. be able to.
  • the present invention is not limited to this, and can be applied to various power conversion devices.
  • a two-level power converter is used.
  • a three-level or multi-level power converter may be used.
  • the present invention is applied to a single-phase inverter. You may apply.
  • the present invention can be applied to a DC / DC converter or an AC / DC converter.
  • the power conversion device to which the present invention is applied is not limited to the case where the load described above is an electric motor.
  • the power source of an electric discharge machine, a laser processing machine, an induction heating cooker, or a non-contact power supply system It can also be used as a device, and can also be used as a power conditioner for a photovoltaic power generation system, a power storage system, or the like.
  • the invention may be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiment.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
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  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
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Abstract

The present invention provides a power module which has improved reliability with respect to a metal bonding part between a cooling device and an insulated circuit board that is sealed with a mold resin. A power module which is characterized by being provided with: an insulating substrate (1) which comprises conductor layers (2, 3) on the upper surface and the lower surface, while having a semiconductor element (5) mounted on the conductor layer (2) on the upper surface, and wherein the conductor layer (3) on the lower surface has a flat surface part (31) on the lower side and a lateral surface part (32) on the lateral side; a sealing resin (7) which seals the insulating substrate (1) so that the flat surface part (31) and a part of the lateral surface part (32) are exposed therefrom; a bonding material (8) which is bonded to the flat surface part (31) and the part of the lateral surface part (32) exposed from the sealing resin (7); and a cooling device (9) which is bonded to the insulating substrate (1), with the bonding material (89 being interposed therebetween.

Description

パワーモジュール、その製造方法および電力変換装置Power module, manufacturing method thereof, and power conversion device
　この発明は、冷却器を備えたモールド樹脂封止型のパワーモジュール、その製造方法およびこのパワーモジュールを備えた電力変換装置に関する。 The present invention relates to a molded resin-encapsulated power module provided with a cooler, a manufacturing method thereof, and a power conversion device provided with the power module.
　従来のパワーモジュールは、セラミック基板の一方の面に接触した導体にはんだ付けされた能動素子がモールド樹脂で封止され、セラミック基板の他方の面に形成された導体膜を有し、モールド樹脂は、セラミック基板の導体膜が形成された面の周縁部を覆い、導体膜と冷却器とが接合されたパワーモジュールが開示されている（例えば、特許文献１）。 In the conventional power module, an active element soldered to a conductor in contact with one surface of a ceramic substrate is sealed with a mold resin, and has a conductor film formed on the other surface of the ceramic substrate. A power module is disclosed in which the peripheral portion of the surface of the ceramic substrate on which the conductor film is formed is covered and the conductor film and the cooler are joined (for example, Patent Document 1).
特開２００３-０３１７６５号公報（第１３頁、第１２図）JP 2003-031765 (page 13, FIG. 12)
　しかしながら、従来のパワーモジュールでは、セラミック基板をモールド樹脂封止したパワーモジュールのセラミック基板の導体層露出部と冷却器との金属接合部は、パワーモジュールと冷却器との熱膨張係数の差が大きく、温度サイクルなどの熱応力で金属接合部に剥離が発生するという問題点があった。 However, in the conventional power module, the difference in the thermal expansion coefficient between the power module and the cooler is large at the metal joint portion between the conductor layer exposed portion of the ceramic substrate and the cooler of the power module in which the ceramic substrate is sealed with mold resin. There is a problem that peeling occurs at the metal joint due to thermal stress such as temperature cycle.
　この発明は、上述のような問題を解決するためになされたもので、モールド樹脂封止された絶縁回路基板と冷却器との金属接合部の信頼性を向上したパワーモジュールを得ることを目的としている。 The present invention has been made to solve the above-described problems, and an object thereof is to obtain a power module in which the reliability of a metal joint portion between an insulating circuit board sealed with a mold resin and a cooler is improved. Yes.
　この発明に係るパワーモジュールは、上面と下面とに導体層を有し、上面の導体層上に半導体素子が搭載された絶縁基板と、下面の導体層は下側に平面部、側面に側面部をそれぞれ有し、平面部と側面部の一部とを露出して絶縁基板を封止する封止樹脂と、封止樹脂から露出した平面部と側面部の一部とに接合する接合材と、接合材を介して絶縁基板と接合された冷却器と、を備えたことを特徴とする。 The power module according to the present invention has a conductor layer on an upper surface and a lower surface, an insulating substrate on which a semiconductor element is mounted on the upper conductor layer, and the lower conductor layer has a flat portion on a lower side and a side portion on a side surface. And a sealing resin that seals the insulating substrate by exposing the flat surface portion and a part of the side surface portion, and a bonding material that bonds the flat surface portion exposed from the sealing resin and a part of the side surface portion. And a cooler bonded to the insulating substrate through a bonding material.
　この発明によれば、絶縁回路基板と冷却器との金属接合部での剥離の発生を抑制でき、パワーモジュールの信頼性を向上させることが可能となる。 According to this invention, it is possible to suppress the occurrence of peeling at the metal joint between the insulating circuit board and the cooler, and to improve the reliability of the power module.
この発明の実施の形態１におけるパワーモジュールを示す平面構造模式図である。It is a planar structure schematic diagram which shows the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールを示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the manufacturing process of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the manufacturing process of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the manufacturing process of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the manufacturing process of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the manufacturing process of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the manufacturing process of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the manufacturing process of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the manufacturing process of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the manufacturing process of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの絶縁基板端部を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the insulated substrate edge part of the power module in Embodiment 1 of this invention. この発明の実施の形態１におけるパワーモジュールの導体層厚さと導体層側面露出長さとの関係図である。It is a related figure of the conductor layer thickness and conductor layer side surface exposure length of the power module in Embodiment 1 of this invention. この発明の実施の形態１における他のパワーモジュールを示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the other power module in Embodiment 1 of this invention. この発明の実施の形態２におけるパワーモジュールを示す平面構造模式図である。It is a plane structure schematic diagram which shows the power module in Embodiment 2 of this invention. この発明の実施の形態２におけるパワーモジュールを示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the power module in Embodiment 2 of this invention. この発明の実施の形態２におけるパワーモジュールを示す製造工程の断面構造模式図である。It is a cross-sectional structure schematic diagram of the manufacturing process which shows the power module in Embodiment 2 of this invention. この発明の実施の形態２におけるパワーモジュールを示す製造工程の断面構造模式図である。It is a cross-sectional structure schematic diagram of the manufacturing process which shows the power module in Embodiment 2 of this invention. この発明の実施の形態２におけるパワーモジュールを示す製造工程の断面構造模式図である。It is a cross-sectional structure schematic diagram of the manufacturing process which shows the power module in Embodiment 2 of this invention. この発明の実施の形態２におけるパワーモジュールのソルダーレジスト形状を示す平面構造模式図である。It is a plane structure schematic diagram which shows the soldering resist shape of the power module in Embodiment 2 of this invention. この発明の実施の形態２におけるパワーモジュールの角部を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the corner | angular part of the power module in Embodiment 2 of this invention. この発明の実施の形態２におけるパワーモジュールの他のソルダーレジスト形状を示す平面構造模式図である。It is a plane structure schematic diagram which shows the other soldering resist shape of the power module in Embodiment 2 of this invention. この発明の実施の形態２におけるパワーモジュールの他のソルダーレジスト形状を示す平面構造模式図である。It is a plane structure schematic diagram which shows the other soldering resist shape of the power module in Embodiment 2 of this invention. この発明の実施の形態２におけるパワーモジュールの他の角部を示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the other corner | angular part of the power module in Embodiment 2 of this invention. この発明の実施の形態２における他のパワーモジュールを示す平面構造模式図である。It is a plane structure schematic diagram which shows the other power module in Embodiment 2 of this invention. この発明の実施の形態３におけるパワーモジュールを示す平面構造模式図である。It is a plane structure schematic diagram which shows the power module in Embodiment 3 of this invention. この発明の実施の形態３におけるパワーモジュールを示す断面構造模式図である。It is a cross-sectional structure schematic diagram which shows the power module in Embodiment 3 of this invention. この発明の実施の形態４における電力変換装置を適用した電力変換システムの構成を示すブロック図である。It is a block diagram which shows the structure of the power conversion system to which the power converter device in Embodiment 4 of this invention is applied.
　はじめに、本発明のパワーモジュールの全体構成について、図面を参照しながら説明する。なお、図は模式的なものであり、示された構成要素の正確な大きさなどを反映するものではない。また、同一の符号を付したものは、同一またはこれに相当するものであり、このことは明細書の全文において共通することである。 First, the overall configuration of the power module of the present invention will be described with reference to the drawings. The drawings are schematic and do not reflect the exact size of the components shown. Moreover, what attached | subjected the same code | symbol is the same or it corresponds, This is common in the whole text of a specification.
実施の形態１．
　図１は、この発明の実施の形態１におけるパワーモジュールを示す平面構造模式図である。図２は、この発明の実施の形態１におけるパワーモジュールを示す断面構造模式図である。図１中の一点鎖線ＡＡにおける断面構造模式図が図２である。図において、パワーモジュール１００は、絶縁回路基板４、半導体素子５、電極端子６、封止樹脂であるモールド樹脂７、接合材８、冷却器９を備えている。 Embodiment 1 FIG.
1 is a schematic plan view showing a power module according to Embodiment 1 of the present invention. FIG. 2 is a schematic cross-sectional structure diagram showing the power module according to Embodiment 1 of the present invention. FIG. 2 is a schematic diagram of a cross-sectional structure taken along one-dot chain line AA in FIG. In the figure, a power module 100 includes an insulating circuit board 4, a semiconductor element 5, an electrode terminal 6, a molding resin 7 that is a sealing resin, a bonding material 8, and a cooler 9.
　絶縁回路基板４は、絶縁基板であるセラミック板１とセラミック板１の上面および下面に形成された導体層２，３を備えている。セラミック板１としては、窒化ケイ素（Ｓｉ３Ｎ４）、窒化アルミ（ＡｌＮ）、アルミナ、Ｚｒ含有アルミナを用いることができる。特に、熱伝導性の点からＡｌＮ、Ｓｉ３Ｎ４が好ましく、材料強度の点からＳｉ３Ｎ４がより好ましい。 The insulated circuit board 4 includes a ceramic plate 1 that is an insulated substrate and conductor layers 2 and 3 formed on the upper and lower surfaces of the ceramic plate 1. As the ceramic plate 1, silicon nitride (Si 3 N 4 ), aluminum nitride (AlN), alumina, or Zr-containing alumina can be used. In particular, AlN and Si 3 N 4 are preferable from the viewpoint of thermal conductivity, and Si 3 N 4 is more preferable from the viewpoint of material strength.
　セラミック板１の両面（上面、下面）に形成されている導体層２，３は、寸法（大きさ）、厚みがともに同じである金属を用いている。ただし、導体層２，３には、それぞれ電気回路が形成されるため、パターン形状が異なる場合がある。また、導体層２，３の大きさは、セラミック板１よりも小さい。導体層２，３の大きさをセラミック板１よりも小さくすることで、導体層２，３間の沿面距離を拡げる（確保）ことができる。さらに、導体層３の大きさをセラミック板１よりも小さくすることで、セラミック板１の下側に封止樹脂７を回り込ませることができる。導体層２，３としては、電気伝導、熱伝導性に優れた金属、例えば、アルミニウムおよびアルミニウム合金、銅および銅合金を用いることができる。特に、熱伝導、電気伝導の観点から銅を用いるのが好ましい。 The conductor layers 2 and 3 formed on both surfaces (upper surface and lower surface) of the ceramic plate 1 are made of metal having the same dimensions (size) and thickness. However, since an electric circuit is formed on each of the conductor layers 2 and 3, the pattern shape may be different. The conductor layers 2 and 3 are smaller than the ceramic plate 1. By making the size of the conductor layers 2 and 3 smaller than that of the ceramic plate 1, the creeping distance between the conductor layers 2 and 3 can be increased (secured). Further, by making the size of the conductor layer 3 smaller than that of the ceramic plate 1, the sealing resin 7 can be made to wrap around the ceramic plate 1. As the conductor layers 2 and 3, metals having excellent electrical conductivity and thermal conductivity, for example, aluminum and aluminum alloys, copper and copper alloys can be used. In particular, it is preferable to use copper from the viewpoints of heat conduction and electric conduction.
　セラミック板１の上面側の導体層２上には、半導体素子５が、例えば、接合材８としてはんだを介して電気的に接合されている。ここで、例えば半導体素子５としては、大電流を制御するＭＯＳＦＥＴ（Ｍｅｔａｌ　Ｏｘｉｄｅ　Ｓｅｍｉｃｏｎｄｕｃｔｏｒ　Ｆｉｅｌｄ　Ｅｆｆｅｃｔ　Ｔｒａｎｓｉｓｔｏｒ）のような電力制御用半導体素子（スイッチング素子）や還流用のダイオード等が用いられる。 On the conductor layer 2 on the upper surface side of the ceramic plate 1, the semiconductor element 5 is electrically joined, for example, as a joining material 8 via solder. Here, as the semiconductor element 5, for example, a power control semiconductor element (switching element) such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) that controls a large current, a free-wheeling diode, or the like is used.
　半導体素子５を構成する材料としては、例えば、珪素（Ｓｉ）以外に炭化珪素（ＳｉＣ）が適用可能である。これらを基板材料として用いたＳｉ半導体素子またはＳｉＣ半導体素子が適用される。 As a material constituting the semiconductor element 5, for example, silicon carbide (SiC) can be applied in addition to silicon (Si). Si semiconductor elements or SiC semiconductor elements using these as substrate materials are applied.
　ＳｉＣ半導体素子は、Ｓｉ半導体素子と比較して非常に硬いため、ＳｉＣ半導体素子厚は０.０８～０.２ｍｍであることが好ましい。ＳｉＣ半導体素子厚を０.０８ｍｍより薄くするためには、非常に硬いＳｉＣウエハを研削するため時間と費用がかかる。また、ＳｉＣ半導体素子厚が０.２ｍｍより厚い場合は、ＳｉＣ半導体素子の放熱性の低下や封止樹脂との界面の熱応力が大きくなる。そのため、ＳｉＣ半導体素子の厚みは０．０８～０．２ｍｍの範囲とすることが良い。 Since the SiC semiconductor element is very hard as compared with the Si semiconductor element, the thickness of the SiC semiconductor element is preferably 0.08 to 0.2 mm. In order to reduce the thickness of the SiC semiconductor element to less than 0.08 mm, it takes time and cost to grind a very hard SiC wafer. Further, when the thickness of the SiC semiconductor element is larger than 0.2 mm, the heat dissipation of the SiC semiconductor element is lowered and the thermal stress at the interface with the sealing resin is increased. Therefore, the thickness of the SiC semiconductor element is preferably in the range of 0.08 to 0.2 mm.
　半導体素子５と絶縁回路基板４の上面側の導体層２との接合は、通常は接合材８として、はんだが用いられる。また、接合材８は、はんだ以外に焼結銀や液相拡散材料が適用可能である。焼結銀や液相拡散材料は、はんだ材料と比較して溶融温度が高く、冷却器９と絶縁回路基板４の下面側の導体層３との接合時に再溶融することがなく、半導体素子５と絶縁回路基板４の接合信頼性が向上する。 Solder is usually used as the bonding material 8 for bonding the semiconductor element 5 and the conductor layer 2 on the upper surface side of the insulating circuit board 4. In addition to the solder, the bonding material 8 may be sintered silver or a liquid phase diffusion material. Sintered silver or a liquid phase diffusion material has a melting temperature higher than that of a solder material, and does not remelt when the cooler 9 and the conductor layer 3 on the lower surface side of the insulated circuit board 4 are joined. And the bonding reliability of the insulating circuit board 4 is improved.
　さらに、焼結銀や液相拡散材料は、はんだより溶融温度が高いため、パワーモジュール１００の動作温度の高温化が可能となる。焼結銀は、熱伝導性がはんだより良好なため、半導体素子５の放熱性が向上して信頼性が向上する。液相拡散材料は、焼結銀より低荷重で接合できるためプロセス性が良好で、接合荷重による半導体素子５へのダメージの影響が防止可能となる。 Furthermore, since sintered silver and liquid phase diffusion materials have a higher melting temperature than solder, the operating temperature of the power module 100 can be increased. Since sintered silver has better thermal conductivity than solder, the heat dissipation of the semiconductor element 5 is improved and the reliability is improved. Since the liquid phase diffusion material can be bonded with a lower load than sintered silver, the processability is good, and the influence of damage to the semiconductor element 5 due to the bonding load can be prevented.
　電極端子６は、半導体素子５上の所定の電極端子６接合位置に接合される。また、電極端子６は、絶縁回路基板４の上面側の導体層２上の所定の電極端子６接合位置にも接合される。電極端子６は、モールド樹脂７の側面側から外部へ突出した構造になっている。電極端子６は、例えば、厚み０.５ｍｍの銅板を、エッチングや金型打ち抜きなどで所定の形状に加工したものが使用可能である。 The electrode terminal 6 is bonded to a predetermined electrode terminal 6 bonding position on the semiconductor element 5. The electrode terminal 6 is also bonded to a predetermined electrode terminal 6 bonding position on the conductor layer 2 on the upper surface side of the insulated circuit board 4. The electrode terminal 6 has a structure protruding from the side surface of the mold resin 7 to the outside. As the electrode terminal 6, for example, a copper plate having a thickness of 0.5 mm processed into a predetermined shape by etching or die punching can be used.
　半導体素子５が接合されていない絶縁回路基板４の下面側の導体層３は、セラミック板１と接する面の反対側である下側に平面部３１、側面に側面部３２をそれぞれ備える。そして、導体層３は、導体層３の下側の平面部３１と側面の側面部３２の一部とが露出するようにモールド樹脂７で封止される。露出した導体層３の平面部３１と側面部３２の一部とは、接合材８を用いて冷却器９に接合されている。ここで、導体層３は、導体層３の平面部３１だけでなく、導体層３の側面部３２の一部にも接合材８が形成されている。この導体層３の側面部３２において、接合材８の形成位置（高さ）としては、モールド樹脂７の冷却器９側となる部分（モールド樹脂７の底部）と接する位置まで形成される。しかしながら、接合材８の形成位置として、モールド樹脂７上に接合材８が接触して（這い上がって）いても良く、また、モールド樹脂７と接合材８とが接触せずに、側面部３２上で離れて形成されていても良い。 The conductor layer 3 on the lower surface side of the insulated circuit board 4 to which the semiconductor element 5 is not bonded includes a flat surface portion 31 on the lower side opposite to the surface in contact with the ceramic plate 1 and a side surface portion 32 on the side surface. The conductor layer 3 is sealed with the mold resin 7 so that the lower flat portion 31 and a part of the side portion 32 on the side surface are exposed. The exposed flat portion 31 and part of the side surface portion 32 of the conductor layer 3 are bonded to the cooler 9 using the bonding material 8. Here, in the conductor layer 3, the bonding material 8 is formed not only on the flat surface portion 31 of the conductor layer 3 but also on a part of the side surface portion 32 of the conductor layer 3. In the side surface portion 32 of the conductor layer 3, the bonding material 8 is formed to a position (height) that contacts the portion of the mold resin 7 on the cooler 9 side (the bottom portion of the mold resin 7). However, as a position where the bonding material 8 is formed, the bonding material 8 may come into contact (climb up) on the mold resin 7, and the side surface portion 32 may be formed without contact between the mold resin 7 and the bonding material 8. It may be formed away from the top.
　モールド樹脂７は、絶縁基板１、導体層２および上記の導体層３の側面部３２の一部を封止する。モールド樹脂７は、例えば、シリカ粒子が充填されたエポキシ樹脂／フェノール樹脂硬化剤系のモールド樹脂が使用可能である。 Mold resin 7 seals a part of insulating substrate 1, conductor layer 2, and side surface portion 32 of conductor layer 3 described above. As the mold resin 7, for example, an epoxy resin / phenol resin curing agent type mold resin filled with silica particles can be used.
　絶縁回路基板４の下面側の導体層３と冷却器９との接合材８は、例えば、はんだが使用可能である。はんだとしては、Ｓｎ－Ｓｂ組成系のはんだ材が接合信頼性の観点で好ましい。絶縁回路基板４の下面側の導体層３と冷却器９との接合は、半導体素子５と絶縁回路基板４との接合の場合と同様に、はんだ以外に焼結銀や液相拡散材料が適用可能である。そして、導体層３の側面部３２と冷却器９との接合部のはんだ形状は、傾斜を持たせたテーパー（フィレット）形状となる。このことより、導体層３の外周部（周縁部）でのはんだの熱応力が緩和され、はんだの剥離が抑制される。ここで、接合材８であるはんだのテーパー形状は、導体層３の側面部３２の絶縁基板１側から冷却器９の外周側へ向かって拡がる（裾引き）形状である。すなわち、導体層３の側面部３２と冷却器９との接合部のはんだ形状は、断面視において、絶縁基板１側の幅よりも冷却器９側の幅が広い形状である。 For example, solder can be used as the bonding material 8 between the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the cooler 9. As the solder, a Sn—Sb composition type solder material is preferable from the viewpoint of bonding reliability. For joining the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9, sintered silver or a liquid phase diffusion material is applied in addition to the solder as in the case of joining the semiconductor element 5 and the insulated circuit board 4. Is possible. And the solder shape of the junction part of the side part 32 of the conductor layer 3 and the cooler 9 becomes a taper (fillet) shape which gave the inclination. As a result, the thermal stress of the solder at the outer peripheral portion (peripheral portion) of the conductor layer 3 is relaxed, and the peeling of the solder is suppressed. Here, the taper shape of the solder, which is the bonding material 8, is a shape that expands from the insulating substrate 1 side of the side surface portion 32 of the conductor layer 3 toward the outer peripheral side of the cooler 9 (bottoming). That is, the solder shape of the joint portion between the side surface portion 32 of the conductor layer 3 and the cooler 9 is a shape in which the width on the cooler 9 side is wider than the width on the insulating substrate 1 side in a sectional view.
　液相拡散材料としては、Ｃｕ－Ｓｎ組成系、Ｃｕ－Ａｇ組成系の材料が接合信頼性の観点で好ましい。焼結銀は熱伝導性がはんだより良好なため、パワーモジュール１００の放熱性が向上して信頼性が向上する。また、液相拡散材料は、焼結銀より低荷重で接合できるためプロセス性が良好で、接合荷重によるパワーモジュール１００へのダメージの影響が防止可能となる。 As the liquid phase diffusion material, a Cu—Sn composition system material or a Cu—Ag composition system material is preferable from the viewpoint of bonding reliability. Since sintered silver has better thermal conductivity than solder, the heat dissipation of the power module 100 is improved and the reliability is improved. In addition, since the liquid phase diffusion material can be bonded with a lower load than sintered silver, the processability is good, and the influence of damage to the power module 100 due to the bonding load can be prevented.
　冷却器９は、例えば、アルミニウムおよびアルミニウム合金、銅および銅合金、ＡｌＳｉＣなどのアルミニウムとセラミックスからなる複合材料を用いることができる。特に、熱伝導性、加工性、軽量の点からアルミニウムおよびアルミニウム合金が好ましい。冷却器９の内部には、冷却のための冷媒を流すための流路が形成されている。図２においては、複数の冷却ピン９１を設けることで、より効率的に冷却することが可能となる。冷却器９の構造としては、この構造に限定されるものではなく、冷却可能な構造であれば適用可能である。 The cooler 9 can be made of, for example, a composite material made of aluminum and ceramics such as aluminum and aluminum alloy, copper and copper alloy, and AlSiC. In particular, aluminum and aluminum alloys are preferable from the viewpoints of thermal conductivity, workability, and light weight. Inside the cooler 9, a flow path for flowing a cooling refrigerant is formed. In FIG. 2, it is possible to cool more efficiently by providing a plurality of cooling pins 91. The structure of the cooler 9 is not limited to this structure, and any structure that can be cooled is applicable.
　次に、上述のように構成された本実施の形態１のパワーモジュール１００の製造方法について説明する。 Next, a method for manufacturing the power module 100 of the first embodiment configured as described above will be described.
　図３から図１１は、この発明の実施の形態１におけるパワーモジュールの各製造工程を示す断面構造模式図である。図３は、この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。図４は、この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。図５は、この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。図６は、この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。図７は、この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。図８は、この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。図９は、この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。図１０は、この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。図１１は、この発明の実施の形態１におけるパワーモジュールの製造工程を示す断面構造模式図である。図３から図１１の工程を経ることにより、パワーモジュール１００を製造することができる。 FIGS. 3 to 11 are schematic cross-sectional views showing the manufacturing steps of the power module according to Embodiment 1 of the present invention. FIG. 3 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention. FIG. 4 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module in the first embodiment of the present invention. FIG. 5 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention. FIG. 6 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention. FIG. 7 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module according to Embodiment 1 of the present invention. FIG. 8 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention. FIG. 9 is a schematic cross-sectional structure diagram illustrating the manufacturing process of the power module according to Embodiment 1 of the present invention. FIG. 10 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module according to Embodiment 1 of the present invention. FIG. 11 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module in the first embodiment of the present invention. The power module 100 can be manufactured through the steps of FIGS.
　はじめに、図３に示すように、セラミック板１の上面に導体層２を、下面に導体層３を形成する（絶縁回路基板形成工程）。セラミック板１と導体層２，３との接合は、ロウ付け等により行う。このとき、導体層２，３は、大きさ、厚さが同じ金属層を用いて形成する。導体層２，３のセラミック板１上での形成位置は、セラミック板１を挟んで対称となる（同じ）位置である。ただし、導体層２，３には、それぞれ電気回路が形成されるため、パターン形状が異なる場合がある。なお、導体層３は、絶縁回路基板４の下面側の導体層３のセラミック板１と接する面の反対側である平面部３１と導体層３の側面部３２と有する。 First, as shown in FIG. 3, the conductor layer 2 is formed on the upper surface of the ceramic plate 1, and the conductor layer 3 is formed on the lower surface (insulating circuit board forming step). The ceramic plate 1 and the conductor layers 2 and 3 are joined by brazing or the like. At this time, the conductor layers 2 and 3 are formed using metal layers having the same size and thickness. The formation positions of the conductor layers 2 and 3 on the ceramic plate 1 are symmetrical (same) positions with the ceramic plate 1 interposed therebetween. However, since an electric circuit is formed on each of the conductor layers 2 and 3, the pattern shape may be different. The conductor layer 3 has a flat surface portion 31 opposite to the surface of the conductor layer 3 on the lower surface side of the insulated circuit board 4 that is in contact with the ceramic plate 1 and a side surface portion 32 of the conductor layer 3.
　次に、図４に示すように、絶縁回路基板４の上面の導体層２上の所定の位置（半導体素子５配置領域または、電極端子６配置領域）に、半導体素子５と電極端子６とを接合材８であるはんだを用いて電気的に接合する。また、半導体素子５上の所定の位置（電極端子６配置領域）に電極端子６を接合材８であるはんだを用いて電気的に接合する（部材接合工程）。このように、絶縁回路基板４上に、半導体素子５と電極端子６とを接合することで、電気回路が形成される。 Next, as shown in FIG. 4, the semiconductor element 5 and the electrode terminal 6 are placed at predetermined positions (semiconductor element 5 arrangement region or electrode terminal 6 arrangement region) on the conductor layer 2 on the upper surface of the insulating circuit substrate 4. It electrically joins using the solder which is the joining material 8. FIG. In addition, the electrode terminal 6 is electrically bonded to a predetermined position on the semiconductor element 5 (electrode terminal 6 arrangement region) using solder which is the bonding material 8 (member bonding step). Thus, an electrical circuit is formed by joining the semiconductor element 5 and the electrode terminal 6 on the insulating circuit substrate 4.
　次に、トランスファーモールド装置（図示せず）を用いて、所定形状に加工した金型内に前工程で作製した絶縁回路基板４を固定してモールド樹脂７で封止する。この後のモールド封止工程では、絶縁回路基板４の下金型１２への設置と下金型１２の上部へ上金型１１の配置とモールド樹脂７の圧入と圧入したモールド樹脂７の硬化とを行う。 Next, using a transfer mold apparatus (not shown), the insulated circuit board 4 produced in the previous step is fixed in a mold processed into a predetermined shape and sealed with a mold resin 7. In the subsequent mold sealing step, the insulating circuit board 4 is placed on the lower mold 12, the upper mold 11 is placed on the lower mold 12, the mold resin 7 is press-fitted, and the press-fitted mold resin 7 is cured. I do.
　図５に示すように、下金型１２を準備（下金型設置工程）し、導体層２上に半導体素子５と電極端子６とを接合した絶縁回路基板４の導体層３を下金型１２に形成したはめ込み部である下金型キャビティー１３にはめ込む（絶縁回路基板設置工程）。この下金型キャビティー１３は、絶縁回路基板４の下面側の導体層３のセラミック板１と接する面の反対側である下側の平面部３１と導体層３の側面の側面部３２の一部とをはめ込むためのものである。下金型キャビティー１３内にはめ込まれた導体層３の部分（平面部３１と側面部３２の一部）は、樹脂封止後、モールド樹脂７では封止されず、モールド樹脂７から露出した領域となる。また、導体層３の下金型キャビティー１３から露出した部分は、樹脂封止後、モールド樹脂７で封止される。 As shown in FIG. 5, the lower mold 12 is prepared (lower mold installation step), and the conductor layer 3 of the insulated circuit board 4 in which the semiconductor element 5 and the electrode terminal 6 are joined on the conductor layer 2 is formed in the lower mold. 12 is inserted into the lower mold cavity 13 which is an inset portion formed in the insulating portion 12 (insulating circuit board installation step). The lower mold cavity 13 includes a lower flat portion 31 on the opposite side of the surface of the conductor layer 3 on the lower surface side of the insulating circuit board 4 that is in contact with the ceramic plate 1 and a side portion 32 on the side surface of the conductor layer 3. It is for fitting the part. The portion of the conductor layer 3 (a part of the flat surface portion 31 and the side surface portion 32) fitted in the lower mold cavity 13 is not sealed with the mold resin 7 after the resin sealing, and is exposed from the mold resin 7. It becomes an area. Further, the portion exposed from the lower mold cavity 13 of the conductor layer 3 is sealed with a mold resin 7 after sealing with resin.
　次に、図６の示すように、下金型１２と上金型１１とを合わせて上下の金型を閉じることで絶縁回路基板４を上金型１１と下金型１２との内部に配置する。このとき、上金型１１と下金型１２とは、電極端子６の一部を金型の側面から突出させた状態で固定される（上金型設置工程）。このように電極端子６を金型の側面から突出させることで、モールド樹脂７で封止後に、電極端子６をモールド樹脂７の外部へと露出させることができる。このとき、電極端子６はモールド樹脂７（図示せず）からの突出位置に合わせて屈曲部を有する構成としても良い。 Next, as shown in FIG. 6, the lower mold 12 and the upper mold 11 are combined and the upper and lower molds are closed to dispose the insulating circuit board 4 inside the upper mold 11 and the lower mold 12. To do. At this time, the upper mold 11 and the lower mold 12 are fixed in a state where a part of the electrode terminal 6 protrudes from the side surface of the mold (upper mold installation step). Thus, by projecting the electrode terminal 6 from the side surface of the mold, the electrode terminal 6 can be exposed to the outside of the mold resin 7 after sealing with the mold resin 7. At this time, the electrode terminal 6 may be configured to have a bent portion in accordance with a protruding position from the mold resin 7 (not shown).
　次に、図７に示すように、内部に絶縁回路基板４を配置した金型内へモールド樹脂７を圧入する。図においては、矢印で示した右側から左側へ向かってモールド樹脂７が圧入される途中の状態を示している。モールド樹脂７としては、例えば、シリカ粒子が充填されたエポキシ樹脂／フェノール樹脂硬化剤系の樹脂（熱膨張係数１２ｐｐｍ／Ｋ）を用いることができる（樹脂封止工程）。また、樹脂材料に合わせた条件（圧力等）で金型内へモールド樹脂７を圧入することでモールド樹脂７により封止できる。 Next, as shown in FIG. 7, a mold resin 7 is press-fitted into a mold in which the insulating circuit board 4 is disposed. In the drawing, a state in which the mold resin 7 is being press-fitted from the right side to the left side indicated by an arrow is shown. As the mold resin 7, for example, an epoxy resin / phenol resin curing agent resin (thermal expansion coefficient 12 ppm / K) filled with silica particles can be used (resin sealing step). Moreover, it can seal with the mold resin 7 by pressing-in the mold resin 7 in a metal mold | die on the conditions (pressure etc.) according to the resin material.
　次に、図８に示すように、モールド樹脂７の圧入の完了後、金型内に絶縁回路基板４を配置したそのままの状態で圧入したモールド樹脂７の硬化処理を実施する。例えば、モールド樹脂７の硬化処理条件としては、１８０℃、３分間の条件で行う（第一の樹脂硬化工程）。このように硬化処理を行うことで圧入されたモールド樹脂７が硬化される。 Next, as shown in FIG. 8, after the press-fitting of the mold resin 7 is completed, the mold resin 7 that has been press-fitted in the state where the insulating circuit board 4 is disposed in the mold is cured. For example, the curing treatment condition for the mold resin 7 is performed at 180 ° C. for 3 minutes (first resin curing step). Thus, the press-fitted mold resin 7 is cured by performing the curing process.
　次に、図９に示すように、上下の金型内からモールド樹脂７での封止が完了した絶縁回路基板４を取り出す（絶縁回路基板取出工程）。このとき、モールド樹脂７は、絶縁回路基板４の上面側の全面と絶縁回路基板４の下面側の導体層３の側面部３２の一部とを封止した状態となっている。そして、導体層３の平面部３１と側面部３２の一部とはモールド樹脂７から露出した状態となっている。この導体層３の側面部３２のモールド樹脂７の位置は、絶縁回路基板４を下金型１２へ配置するときに、導体層３を設置した下金型キャビティー１３のはめ込み量（深さ）により決定される。 Next, as shown in FIG. 9, the insulating circuit board 4 that has been sealed with the mold resin 7 is taken out from the upper and lower molds (insulating circuit board removing step). At this time, the mold resin 7 is in a state in which the entire upper surface side of the insulating circuit substrate 4 and a part of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit substrate 4 are sealed. The planar portion 31 and part of the side surface portion 32 of the conductor layer 3 are exposed from the mold resin 7. The position of the mold resin 7 on the side surface portion 32 of the conductor layer 3 is such that when the insulating circuit board 4 is placed on the lower mold 12, the amount of insertion (depth) of the lower mold cavity 13 in which the conductor layer 3 is installed. Determined by.
　すなわち、この下金型キャビティー１３の深さが、導体層３の側面部３２のモールド樹脂７からの露出量を決定する。そして、この下金型キャビティー１３の深さを調整することで、所望の特性（剥離特性、絶縁特性）を得ることができる。 That is, the depth of the lower mold cavity 13 determines the exposure amount of the side surface portion 32 of the conductor layer 3 from the mold resin 7. Then, by adjusting the depth of the lower mold cavity 13, desired characteristics (peeling characteristics, insulating characteristics) can be obtained.
　さらに、図９に示した上下の金型から取り出したモールド樹脂７で封止された絶縁回路基板４は、オーブン中で１７５℃、６時間の条件でモールド樹脂７の硬化処理を行う（第二の樹脂硬化工程）。これらの工程を経ることにより、モールド樹脂７で封止された絶縁回路基板４が完成する。 Further, the insulating circuit board 4 sealed with the mold resin 7 taken out from the upper and lower molds shown in FIG. 9 is subjected to a curing treatment of the mold resin 7 in an oven at 175 ° C. for 6 hours (second process). Resin curing step). Through these steps, the insulated circuit board 4 sealed with the mold resin 7 is completed.
　次に、図１０に示すように、モールド樹脂７で樹脂封止された絶縁回路基板４は、接合材８を介して、冷却器９の所定の位置へ治具を用いて固定される（冷却器配置工程）。 Next, as shown in FIG. 10, the insulating circuit board 4 resin-sealed with the mold resin 7 is fixed to a predetermined position of the cooler 9 with a jig through the bonding material 8 (cooling). Container placement step).
　絶縁回路基板４と接合材８とを冷却器９に固定後、図１１に示すように、リフロー炉を用いて接合材８をリフローすることで接合材８が溶融し、モールド樹脂７から露出した絶縁回路基板４の下面側の導体層３の平面部３１と側面部３２の一部（露出部）と冷却器９とが接合材８を介して接合される（冷却器接合工程）。 After fixing the insulating circuit board 4 and the bonding material 8 to the cooler 9, the bonding material 8 is melted and exposed from the mold resin 7 by reflowing the bonding material 8 using a reflow furnace as shown in FIG. 11. The plane portion 31 and part of the side surface portion 32 (exposed portion) of the conductor layer 3 on the lower surface side of the insulated circuit board 4 are bonded to the cooler 9 via the bonding material 8 (cooler bonding step).
　以上の主要な製造工程を経ることで、パワーモジュール１００が製造できる。 The power module 100 can be manufactured through the above main manufacturing processes.
　次に、上記の製造工程を用いて試作した本実施の形態１のパワーモジュール１００の導体層３の厚さと導体層３の露出量を変えたときの剥離特性および絶縁特性について説明する。 Next, the peeling characteristics and the insulating characteristics when the thickness of the conductor layer 3 and the exposure amount of the conductor layer 3 of the power module 100 of the first embodiment manufactured using the above manufacturing process are changed will be described.
　評価に用いたパワーモジュール１００の基本構造は、以下の通りである。 The basic structure of the power module 100 used for the evaluation is as follows.
　半導体素子５としては、Ｓｉ半導体素子を用いる。そして、外形が２０ｍｍ×２０ｍｍの絶縁回路基板４の所定の位置に０.１ｍｍ厚のＳｉ半導体素子をはんだで接合する。そして、電極端子６を絶縁回路基板４、Ｓｉ半導体素子の所定の位置にはんだ接合する。 As the semiconductor element 5, a Si semiconductor element is used. Then, a 0.1 mm-thick Si semiconductor element is joined to a predetermined position of the insulated circuit board 4 having an outer shape of 20 mm × 20 mm with solder. Then, the electrode terminal 6 is soldered to a predetermined position of the insulating circuit board 4 and the Si semiconductor element.
　絶縁回路基板４の仕様は、厚さ０.３２ｍｍのＳｉ３Ｎ４のセラミック板１の両面に厚さ０.７ｍｍで大きさが１６ｍｍ×１６ｍｍの導体層２，３である銅パターンが形成されている。ここで、導体層２，３の大きさは、セラミック板１大きさよりも小さく、セラミック板１から、導体層２，３がはみ出すことはない。 Specifications of the insulating circuit board 4, the copper pattern is formed is a conductive layer 2 and 3 of 16 mm × 16 mm in thickness 0.7mm size on both surfaces of the ceramic plate 1 of a thickness of 0.32 mm Si 3 N 4 ing. Here, the size of the conductor layers 2 and 3 is smaller than the size of the ceramic plate 1, and the conductor layers 2 and 3 do not protrude from the ceramic plate 1.
　トランスファーモールド封止に用いる下金型１２には、大きさ１６ｍｍ×１６ｍｍで深さ０.５ｍｍの絶縁回路基板４の下面側の導体層３の平面部３１と側面部３２の一部とをはめ込む下金型キャビティー１３が形成されている。このため、絶縁回路基板４のセラミック板１の全面がモールド樹脂７で封止され、セラミック板１に形成された下面側の導体層３の下側の平面部３１と側面部３２のうちの平面部３１の表面からセラミック板１に向かって高さ０.５ｍｍを露出させてモールド樹脂７で封止される（導体層３の側面部３２のセラミック板１から下側へ０．２ｍｍの位置までをモールド樹脂７で封止した）。 The lower mold 12 used for transfer mold sealing is fitted with the flat portion 31 and part of the side portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit board 4 having a size of 16 mm × 16 mm and a depth of 0.5 mm. A lower mold cavity 13 is formed. For this reason, the entire surface of the ceramic plate 1 of the insulating circuit board 4 is sealed with the mold resin 7, and the plane of the lower planar portion 31 and the side portion 32 formed on the lower surface of the conductor layer 3 formed on the ceramic plate 1. A height of 0.5 mm is exposed from the surface of the portion 31 toward the ceramic plate 1 and is sealed with a mold resin 7 (from the ceramic plate 1 of the side surface portion 32 of the conductor layer 3 to a position of 0.2 mm downward) Was sealed with mold resin 7).
　絶縁回路基板４の下面側の導体層３と冷却器９との接合は、接合材８として大きさ１６ｍｍ×１６ｍｍ、厚さ０.３ｍｍのフィルム状のはんだを使用する。そして、冷却器９の所定位置に、絶縁回路基板４の下面側の導体層３とフィルム状のはんだとを冶具で固定して、リフロー炉で加熱することにより接合した。 For joining the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the cooler 9, a film-like solder having a size of 16 mm × 16 mm and a thickness of 0.3 mm is used as the bonding material 8. Then, the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the film-like solder were fixed to a predetermined position of the cooler 9 with a jig, and joined by heating in a reflow furnace.
　絶縁回路基板４の下面側の導体層３と冷却器９との接合時、はんだは、絶縁回路基板４の下面側の導体層３の下金型１２の下金型キャビティー１３内にはめ込まれていたモールド樹脂７から露出した部分（平面部３１と側面部３２の一部）と接合する。 When the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 are joined, the solder is inserted into the lower mold cavity 13 of the lower mold 12 of the conductor layer 3 on the lower surface side of the insulated circuit board 4. It joins with the part (a part of plane part 31 and side part 32) exposed from mold resin 7 which had been.
　ここで、冷却器９は、アルミニウム製で、大きさ６０ｍｍ×６０ｍｍ、厚さ１５ｍｍの外形で、外形２０ｍｍ×２０ｍｍの絶縁回路基板４が６個接合できる大きさである。 Here, the cooler 9 is made of aluminum, and has a size of 60 mm × 60 mm and a thickness of 15 mm, and is capable of joining six insulated circuit boards 4 having a size of 20 mm × 20 mm.
　絶縁回路基板４の下面側の導体層３と冷却器９との接合時に、絶縁回路基板４の下面側の導体層３と冷却器９との間のはんだ厚は、０.２５ｍｍとなるように調整している。そのため、はんだが絶縁回路基板４の露出した下面側の導体層３の平面部３１からはみ出し、下面側の導体層３の側面部３２の０.５ｍｍ露出した部分に沿ってはんだが形成される。導体層３の側面部３２に形成されたはんだ形状は、セラミック板１側から冷却器９へ向かうテーパー形状であり、冷却器９上面で冷却器９の外周部へ向かって拡がる裾引き（フィレット）形状である。すなわち、導体層３の側面部３２と冷却器９との接合部のはんだ形状は、断面視において、絶縁基板１側の幅よりも冷却器９側の幅が広い形状である。 When the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 are joined, the solder thickness between the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 is 0.25 mm. It is adjusted. Therefore, the solder protrudes from the exposed flat surface portion 31 of the conductor layer 3 on the lower surface side of the insulated circuit board 4 and is formed along the 0.5 mm exposed portion of the side surface portion 32 of the lower surface side conductor layer 3. The solder shape formed on the side surface portion 32 of the conductor layer 3 is a taper shape from the ceramic plate 1 side toward the cooler 9, and a skirt (fillet) extending toward the outer peripheral portion of the cooler 9 on the upper surface of the cooler 9. Shape. That is, the solder shape of the joint portion between the side surface portion 32 of the conductor layer 3 and the cooler 9 is a shape in which the width on the cooler 9 side is wider than the width on the insulating substrate 1 side in a sectional view.
　絶縁回路基板４の下面側の導体層３と冷却器９との間のはんだ厚の調整は、冷却器９の表面上（上面）にワイヤボンダで０.２５ｍｍのボンディングワイヤのスペーサを形成することで、厚さが０.２５ｍｍとなるよう制御した。 The solder thickness between the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 is adjusted by forming a 0.25 mm bonding wire spacer on the surface (upper surface) of the cooler 9 with a wire bonder. The thickness was controlled to be 0.25 mm.
　図１２は、この発明の実施の形態１におけるパワーモジュールの絶縁基板端部を示す断面構造模式図である。図において、絶縁回路基板４の下面側の導体層３の厚さをｔ（ｍｍ）、モールド樹脂７封止後の絶縁回路基板４の下面側の導体層３の側面部３２でモールド樹脂７からの導体層３の露出長さをＬ（ｍｍ）とした。 FIG. 12 is a schematic cross-sectional structure diagram showing the end portion of the insulating substrate of the power module according to Embodiment 1 of the present invention. In the figure, the thickness of the conductor layer 3 on the lower surface side of the insulated circuit board 4 is t (mm), and the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulated circuit board 4 after sealing with the mold resin 7 The exposed length of the conductor layer 3 was L (mm).
　表１に、試作したパワーモジュールの仕様と温度サイクル試験剥離判定結果、絶縁試験判定結果を示す。 Table 1 shows the specifications of the prototype power module, the temperature cycle test peeling determination result, and the insulation test determination result.
　評価サンプル例１～１８は、絶縁回路基板４の下面側の導体層３の厚さ（ｔ）および導体層３の側面部３２でのモールド樹脂７からの露出長さ（Ｌ）が異なるだけで、上記と同様の方法でパワーモジュールを試作した。導体層３の側面部３２のモールド樹脂７からの露出長さは、下金型キャビティー１３の深さによって決定される。 Evaluation sample examples 1 to 18 differ only in the thickness (t) of the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the exposed length (L) from the mold resin 7 on the side surface portion 32 of the conductor layer 3. A power module was prototyped by the same method as described above. The exposed length of the side surface portion 32 of the conductor layer 3 from the mold resin 7 is determined by the depth of the lower mold cavity 13.
　試作したパワーモジュールの絶縁回路基板４の下面側の導体層３と冷却器９とのはんだ接合部の剥離判定は、超音波映像装置ＦｉｎｅＳＡＴ（日立エンジニアリングアンドサービス社製）で行った。そして、剥離観察は、初期と温度サイクル試験（－４０～１２５℃、各３０分）を１０００サイクル後に行った。 Separation determination of the solder joint between the conductor layer 3 on the lower surface side of the insulated circuit board 4 of the prototype power module and the cooler 9 was performed with an ultrasonic imaging apparatus FineSAT (manufactured by Hitachi Engineering & Service). The peeling observation was performed after 1000 cycles of the initial and temperature cycle tests (−40 to 125 ° C., 30 minutes each).
　表１には、温度サイクル後に剥離が観察されない場合は「ＯＫ」、剥離が観察された場合は「ＮＧ」で評価結果を示した。 Table 1 shows the evaluation results as “OK” when no peeling was observed after the temperature cycle, and “NG” when peeling was observed.
　また、試作したパワーモジュールの温度サイクル試験（－４０～１２５℃、各３０分）を１０００サイクル後に、絶縁回路基板４の上面側の導体層２と冷却器９との間に電圧３.０ｋＶを１分間印加して、絶縁回路基板４の上面側の導体層２と冷却器９との絶縁が確保できた場合は「ＯＫ」、絶縁破壊した場合は「ＮＧ」で評価結果を示した。 Further, after 1000 cycles of the temperature cycle test (−40 to 125 ° C., 30 minutes each) of the prototype power module, a voltage of 3.0 kV was applied between the conductor layer 2 on the upper surface side of the insulating circuit board 4 and the cooler 9. When the insulation between the conductor layer 2 on the upper surface side of the insulating circuit board 4 and the cooler 9 was ensured by applying for 1 minute, the evaluation result was shown as “OK”, and when the insulation breakdown, “NG”.
Figure JPOXMLDOC01-appb-T000001
 　図１３は、この発明の実施の形態１におけるパワーモジュールの導体層厚さと導体層側面露出長さとの関係図である。表１における温度サイクル試験後の剥離判定と絶縁試験判定において、共に判定が「ＯＫ」となった条件について示している。
Figure JPOXMLDOC01-appb-T000001
 FIG. 13 is a relationship diagram between the conductor layer thickness and the conductor layer side surface exposed length of the power module according to Embodiment 1 of the present invention. Table 1 shows the conditions for which the determination was “OK” in both the peel determination and the insulation test determination after the temperature cycle test.
　図１３において、グラフ中の「黒丸」は、導体層３の各厚さｔにおいて、温度サイクル試験判定で合格判定となる導体層３の側面部３２の露出長さＬを示している。この「黒丸」より下の露出長さＬの領域は、温度サイクル試験判定で不合格となる領域で、この「黒丸」より上の露出長さＬの領域は、温度サイクル試験判定で合格となる領域である。温度サイクル試験で合格判定となる導体層３の側面部３２の露出長さＬは、導体層３の厚さｔと相関があり、以下で示されることがわかった。 In FIG. 13, “black circles” in the graph indicate the exposed length L of the side surface portion 32 of the conductor layer 3 that becomes a pass determination in the temperature cycle test determination at each thickness t of the conductor layer 3. The region of the exposure length L below the “black circle” is a region that fails the temperature cycle test determination, and the region of the exposure length L above the “black circle” passes the temperature cycle test determination. It is an area. It has been found that the exposed length L of the side surface portion 32 of the conductor layer 3 that is determined to pass in the temperature cycle test has a correlation with the thickness t of the conductor layer 3 and is shown below.
Figure JPOXMLDOC01-appb-M000002
Figure JPOXMLDOC01-appb-M000002
　ここで、導体層３の側面部３２の露出長さＬは、はんだのテーパー（フィレット）高さとなる。導体層３の側面部３２へのはんだの形状をテーパー形成とすることにより、導体層３の外周部（周縁部）でのはんだの熱応力が緩和され、絶縁回路基板４と冷却器９との金属接合部でのはんだの接合信頼性が向上する。 Here, the exposed length L of the side surface portion 32 of the conductor layer 3 is the taper (fillet) height of the solder. By making the shape of the solder on the side surface portion 32 of the conductor layer 3 tapered, the thermal stress of the solder on the outer peripheral portion (peripheral portion) of the conductor layer 3 is relieved, and the insulation circuit substrate 4 and the cooler 9 are Solder joint reliability at the metal joint is improved.
　しかし、テーパー高さが低い場合は、はんだの熱応力の緩和効果が十分ではなく、絶縁回路基板４と冷却器９とのはんだ接合部（金属接合部）に剥離が発生する。これらより、導体層３の側面部３２の露出長さＬには、導体層３の厚さｔに対して適正な領域があることがわかる。 However, when the taper height is low, the thermal stress relaxation effect of the solder is not sufficient, and peeling occurs at the solder joint (metal joint) between the insulating circuit board 4 and the cooler 9. From these, it can be seen that the exposed length L of the side surface portion 32 of the conductor layer 3 has an appropriate region with respect to the thickness t of the conductor layer 3.
　図１３のグラフ中の「黒四角」は、導体層３の各厚さｔにおいて、絶縁試験で合格判定となる導体層３の側面部３２の露出長さLを示している。この「黒四角」より下の露出長さＬの領域は、絶縁試験判定で合格となる領域、この「黒四角」より上の露出長さＬの領域は、絶縁試験判定で不合格となる領域である。絶縁試験で合格判定となる導体層の側面部３２の露出長さＬは、導体層厚ｔと相関があり、以下で示されることがわかった。 “Black squares” in the graph of FIG. 13 indicate the exposed length L of the side surface portion 32 of the conductor layer 3 that is determined to pass in the insulation test at each thickness t of the conductor layer 3. The region of the exposure length L below the “black square” is a region that passes the insulation test determination, and the region of the exposure length L above the “black square” is a region that fails the insulation test determination. It is. It has been found that the exposed length L of the side surface portion 32 of the conductor layer, which is determined to pass in the insulation test, has a correlation with the conductor layer thickness t and is shown below.
Figure JPOXMLDOC01-appb-M000003
Figure JPOXMLDOC01-appb-M000003
　ここで、パワーモジュール１００の絶縁破壊経路は、電界強度が最大となる半導体素子５が搭載された絶縁回路基板４の上面側の導体層２の端部を起点にセラミック板１とモールド樹脂７との界面から冷却器９に到る。 Here, the dielectric breakdown path of the power module 100 is based on the ceramic plate 1 and the mold resin 7 starting from the end of the conductor layer 2 on the upper surface side of the insulated circuit board 4 on which the semiconductor element 5 having the maximum electric field strength is mounted. From the interface to the cooler 9.
　このため、絶縁回路基板４をモールド樹脂７で封止することにより、モールド樹脂７で封止しない場合と比較して、絶縁耐圧は大きく向上する。しかしながら、セラミック板１とモールド樹脂７との界面に剥離やクラックが発生するとモールド樹脂７で封止しない状態に近づくため絶縁特性が低下する。温度サイクル試験後に、絶縁試験判定で合格するためには、温度サイクル試験で、セラミック板１とモールド樹脂７との界面の剥離やクラックを防止する必要がある。 Therefore, by sealing the insulating circuit board 4 with the mold resin 7, the withstand voltage is greatly improved as compared with the case where the insulating circuit board 4 is not sealed with the mold resin 7. However, if peeling or cracking occurs at the interface between the ceramic plate 1 and the mold resin 7, the insulating properties are deteriorated because it approaches a state where the mold resin 7 is not sealed. In order to pass the insulation test determination after the temperature cycle test, it is necessary to prevent peeling and cracking at the interface between the ceramic plate 1 and the mold resin 7 in the temperature cycle test.
　導体層３の厚さｔと導体層３の側面部３２の露出長さＬとの差が、絶縁回路基板４のセラミック板１の下面側に接着している（下面側を封止している）モールド樹脂７の厚さとなる。 The difference between the thickness t of the conductor layer 3 and the exposed length L of the side surface portion 32 of the conductor layer 3 is adhered to the lower surface side of the ceramic plate 1 of the insulating circuit substrate 4 (the lower surface side is sealed). ) The thickness of the mold resin 7 is obtained.
　絶縁回路基板４のセラミック板１の下面側のモールド樹脂７の厚さが薄い場合は、モールド樹脂７成形時にセラミック板１と金型との間隔が狭く、十分なモールド樹脂７の注入（浸入）が出来ず、セラミック板１とモールド樹脂７との間に剥離やボイドが発生する。 When the thickness of the mold resin 7 on the lower surface side of the ceramic plate 1 of the insulating circuit board 4 is thin, the gap between the ceramic plate 1 and the mold is narrow at the time of molding the mold resin 7 and sufficient injection (intrusion) of the mold resin 7 is performed. Peeling and voids are generated between the ceramic plate 1 and the mold resin 7.
　また、温度サイクル試験では、この部分のモールド樹脂７の厚さが薄い場合は、モールド樹脂７の強度が不足して、セラミック板１とモールド樹脂７との間に剥離やクラックが発生する。 Further, in the temperature cycle test, when the thickness of the mold resin 7 in this portion is thin, the strength of the mold resin 7 is insufficient, and peeling or cracking occurs between the ceramic plate 1 and the mold resin 7.
　このように、モールド樹脂７の厚さが薄い場合は、モールド樹脂７の成形不良や温度サイクル試験でのセラミック板１とモールド樹脂７との間に剥離やクラックで絶縁不良が発生する。そのため、絶縁回路基板４のセラミック板１の下面側に接着しているモールド樹脂７の樹脂厚には下限値があり、厚さとして０.２ｍｍ以上必要であることがわかった。 As described above, when the thickness of the mold resin 7 is small, a molding failure of the mold resin 7 or an insulation failure occurs due to peeling or cracking between the ceramic plate 1 and the mold resin 7 in the temperature cycle test. Therefore, it has been found that the resin thickness of the mold resin 7 adhered to the lower surface side of the ceramic plate 1 of the insulating circuit board 4 has a lower limit value, and the thickness is required to be 0.2 mm or more.
　以上より、絶縁回路基板４と冷却器９との接合信頼性とパワーモジュール１００の絶縁信頼性の両方を確保するためには、導体層３の側面部３２の露出長さＬに適正値があり、式（３）を満たす必要があることがわかった。また、導体層３の厚さが０.４ｍｍの場合、両方の試験を合格する領域はなかった。 From the above, in order to ensure both the bonding reliability between the insulating circuit board 4 and the cooler 9 and the insulating reliability of the power module 100, the exposed length L of the side surface portion 32 of the conductor layer 3 has an appropriate value. It was found that the formula (3) needs to be satisfied. Moreover, when the thickness of the conductor layer 3 was 0.4 mm, there was no area | region which passed both tests.
Figure JPOXMLDOC01-appb-M000004
Figure JPOXMLDOC01-appb-M000004
　導体層３の厚さが厚くなると、絶縁回路基板４と冷却器９との接合信頼性とパワーモジュール１００の絶縁信頼性の両方を確保可能な領域は増加する。しかしながら、絶縁回路基板４の製造上の制約や絶縁回路基板４自体の温度サイクル試験耐性の制約から導体層３の厚さの上限にも制約がある。 As the thickness of the conductor layer 3 increases, the area where both the bonding reliability between the insulating circuit board 4 and the cooler 9 and the insulation reliability of the power module 100 can be secured increases. However, the upper limit of the thickness of the conductor layer 3 is also restricted due to restrictions in manufacturing the insulated circuit board 4 and restrictions on the temperature cycle test resistance of the insulated circuit board 4 itself.
　導体層３をエッチングで製造する場合、導体層３の厚さに比例してエッチング時間が長くなり製造コストが高くなる。また、導体層３を厚くすると、セラミック板１と導体層３との界面で熱応力が大きくなり、絶縁回路基板４単体での温度サイクル試験でもセラミック板１の割れが発生する。このため、導体層３の厚さの上限値は１.０ｍｍである。 When the conductor layer 3 is manufactured by etching, the etching time is increased in proportion to the thickness of the conductor layer 3 and the manufacturing cost is increased. When the conductor layer 3 is thickened, thermal stress increases at the interface between the ceramic plate 1 and the conductor layer 3, and cracking of the ceramic plate 1 occurs even in a temperature cycle test with the insulated circuit board 4 alone. For this reason, the upper limit of the thickness of the conductor layer 3 is 1.0 mm.
　図１４は、この発明の実施の形態１における他のパワーモジュールを示す断面構造模式図である。図において、パワーモジュール２００は、冷却器９の上に２つのモールド樹脂７で封止された絶縁回路基板４を備えている。このように、冷却器９の大きさを調整することで、複数個のモールド樹脂７で封止された絶縁回路基板４を配置することが可能となる。 FIG. 14 is a schematic cross-sectional view showing another power module according to Embodiment 1 of the present invention. In the figure, the power module 200 includes an insulated circuit board 4 sealed with two mold resins 7 on a cooler 9. In this way, by adjusting the size of the cooler 9, it is possible to arrange the insulated circuit board 4 sealed with a plurality of mold resins 7.
　以上のように構成されたパワーモジュールにおいては、モールド樹脂７で封止された絶縁回路基板４の下面側の導体層３の側面部３２の一部をモールド樹脂７で封止し、モールド樹脂７から露出した導体層３の平面部３１と側面部３２の一部と冷却器９とを接合材８で接合したので、この金属接合部での剥離の発生が抑制できる。その結果、パワーモジュールの信頼性を向上させることが可能となる。 In the power module configured as described above, a part of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit substrate 4 sealed with the mold resin 7 is sealed with the mold resin 7. Since the planar portion 31 and part of the side surface portion 32 of the conductor layer 3 exposed from above and the cooler 9 are joined by the joining material 8, the occurrence of peeling at the metal joining portion can be suppressed. As a result, it becomes possible to improve the reliability of the power module.
　また、モールド樹脂７から露出した導体層３の側面部３２の一部と冷却器９とを接合材８で接合した接合部の形状をテーパー（フィレット）形状としたので、金属接合部での熱応力の発生が抑制でき、パワーモジュールの信頼性を向上させることが可能となる。 In addition, since the shape of the joined portion obtained by joining a part of the side surface portion 32 of the conductor layer 3 exposed from the mold resin 7 and the cooler 9 with the joining material 8 is a taper (fillet) shape, the heat at the metal joined portion The generation of stress can be suppressed, and the reliability of the power module can be improved.
実施の形態２．
　本実施の形態２においては、実施の形態１で用いた絶縁回路基板４の下面側の導体層３と冷却器９との接合形成において、冷却器９の上面にソルダーレジスト１０を形成した点が異なる。このように、冷却器９の上面にソルダーレジスト１０を形成したので、導体層３と冷却器９との接合時の接合材８の流動領域を制限することができ、確実に導体層３の側面部３２の露出領域を接合材８で覆うことができる。その結果、パワーモジュールの信頼性を向上させることが可能となる。なお、その他の点については、実施の形態１と同様であるので、詳しい説明は省略する。 Embodiment 2. FIG.
In the second embodiment, the solder resist 10 is formed on the upper surface of the cooler 9 when the conductor layer 3 on the lower surface side of the insulated circuit board 4 used in the first embodiment and the cooler 9 are joined. Different. Thus, since the solder resist 10 is formed on the upper surface of the cooler 9, the flow region of the bonding material 8 at the time of bonding between the conductor layer 3 and the cooler 9 can be restricted, and the side surface of the conductor layer 3 is surely The exposed region of the portion 32 can be covered with the bonding material 8. As a result, it becomes possible to improve the reliability of the power module. Since other points are the same as those in the first embodiment, detailed description thereof is omitted.
　図１５は、この発明の実施の形態２におけるパワーモジュールを示す平面構造模式図である。図１６は、この発明の実施の形態２におけるパワーモジュールを示す断面構造模式図である。図１５中の一点鎖線ＢＢにおける断面構造模式図が図１６である。図において、パワーモジュール３００は、絶縁回路基板４、半導体素子５、電極端子６、封止樹脂であるモールド樹脂７、接合材８、冷却器９、ソルダーレジスト１０を備えている。ソルダーレジスト１０を形成した以外は、実施の形態１と同様である。 FIG. 15 is a schematic plan view showing the power module according to Embodiment 2 of the present invention. FIG. 16 is a schematic cross-sectional structure diagram showing a power module according to Embodiment 2 of the present invention. FIG. 16 is a schematic diagram of a cross-sectional structure taken along one-dot chain line BB in FIG. In the figure, a power module 300 includes an insulating circuit board 4, a semiconductor element 5, an electrode terminal 6, a molding resin 7 as a sealing resin, a bonding material 8, a cooler 9, and a solder resist 10. Except that the solder resist 10 is formed, it is the same as the first embodiment.
　ソルダーレジスト１０は、冷却器９の上面である絶縁回路基板４の下面側の導体層３が接合材８で接合される面に形成されている。ソルダーレジスト１０は、冷却器９の上面で接合材８の外周部を囲む領域に設けられている。このとき、ソルダーレジスト１０は、接合材８と所定の間隔を設けて形成されている。そのため、ソルダーレジスト１０は、接合材８が所定の間隔をあけて配置できるように中央領域に開口部１０１を有している。ソルダーレジスト１０の目的は、接合材８が冷却器９の上面で拡がる領域を制限するために配置する。すなわち、ソルダーレジスト１０は、導体層３の側面部３２に形成される接合材８を、精度良くテーパー形状とできる位置に配置される。 The solder resist 10 is formed on a surface where the conductor layer 3 on the lower surface side of the insulating circuit board 4 which is the upper surface of the cooler 9 is bonded by the bonding material 8. The solder resist 10 is provided in a region surrounding the outer periphery of the bonding material 8 on the upper surface of the cooler 9. At this time, the solder resist 10 is formed with a predetermined distance from the bonding material 8. Therefore, the solder resist 10 has an opening 101 in the central region so that the bonding material 8 can be arranged at a predetermined interval. The purpose of the solder resist 10 is arranged to limit the region where the bonding material 8 spreads on the upper surface of the cooler 9. That is, the solder resist 10 is disposed at a position where the bonding material 8 formed on the side surface portion 32 of the conductor layer 3 can be accurately tapered.
　ソルダーレジスト１０は、冷却器９への接着性や耐熱性が確保可能であれば、一般的な市販品が適用可能である。 As the solder resist 10, a general commercial product can be applied as long as adhesion to the cooler 9 and heat resistance can be secured.
　次に、ソルダーレジスト１０を用いた場合の製造工程について説明する。 Next, the manufacturing process when the solder resist 10 is used will be described.
　図１７は、この発明の実施の形態２におけるパワーモジュールの製造工程を示す断面構造模式図である。図１８は、この発明の実施の形態２におけるパワーモジュールの製造工程を示す断面構造模式図である。図１９は、この発明の実施の形態２におけるパワーモジュールの製造工程を示す断面構造模式図である。実施の形態１のパワーモジュール１００の製造工程において、図１７は図９の製造工程の後に実施し、図１８、図１９は、図１０、図１１に示した製造工程と置き換えることで、ソルダーレジスト１０を用いたパワーモジュール３００を製造することができる。 FIG. 17 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module in the second embodiment of the present invention. FIG. 18 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module in the second embodiment of the present invention. FIG. 19 is a schematic cross-sectional structure diagram showing the manufacturing process of the power module according to Embodiment 2 of the present invention. In the manufacturing process of the power module 100 of the first embodiment, FIG. 17 is performed after the manufacturing process of FIG. 9, and FIGS. 18 and 19 are replaced with the manufacturing process shown in FIGS. The power module 300 using 10 can be manufactured.
　図３から図９の製造工程の後に、図１７に示すように、ソルダーレジスト１０は、冷却器９の上面の外周部に形成される。（ソルダーレジスト形成工程）。このとき、ソルダーレジスト１０は、冷却器９の上面の中央領域に開口部１０１を有して形成される。 3 to FIG. 9, the solder resist 10 is formed on the outer peripheral portion of the upper surface of the cooler 9 as shown in FIG. 17. (Solder resist forming step). At this time, the solder resist 10 is formed with the opening 101 in the central region of the upper surface of the cooler 9.
　次に、図１０の換わりに図１８に示すように、接合材８は、ソルダーレジスト１０で囲まれた開口部１０１内に配置される。そして、モールド樹脂７で樹脂封止された絶縁回路基板４は、接合材８を介して、ソルダーレジスト１０で外周部を覆われた冷却器９の上面の中央領域の所定の位置へ治具を用いて固定される（冷却器配置工程）。 Next, as shown in FIG. 18 instead of FIG. 10, the bonding material 8 is disposed in the opening 101 surrounded by the solder resist 10. Then, the insulating circuit board 4 encapsulated with the mold resin 7 is bonded to a predetermined position in the central region of the upper surface of the cooler 9 whose outer periphery is covered with the solder resist 10 via the bonding material 8. It is fixed using (cooler arrangement process).
　モールド樹脂７で樹脂封止された絶縁回路基板４を接合材８を介して冷却器９へ固定後、図１１の換わりに図１９に示すように、リフロー炉を用いて接合材８をリフローすることで接合材８が溶融し、モールド樹脂７から露出した絶縁回路基板４の下面側の導体層３の平面部３１と側面部３２の一部（露出部）と冷却器９とが接合される（冷却器接合工程）。 After fixing the insulating circuit board 4 resin-sealed with the mold resin 7 to the cooler 9 via the bonding material 8, the bonding material 8 is reflowed using a reflow furnace as shown in FIG. 19 instead of FIG. As a result, the bonding material 8 is melted, and the flat portion 31 and the portion (exposed portion) of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit substrate 4 exposed from the mold resin 7 are bonded to the cooler 9. (Cooler joining process).
　このとき、接合材８は、冷却器９の上面の外周部にソルダーレジスト１０を配置したことで、リフロー時の拡がる範囲（領域）が制限される。すなわち、ソルダーレジスト１０の開口部１０１の内部で拡がることになる。ソルダーレジスト１０によって、接合材８は、拡散が制限され導体層３の周辺角部へ集まることで、導体層３の側面部３２の露出部を確実に覆うことができる。 At this time, the bonding material 8 has the solder resist 10 disposed on the outer peripheral portion of the upper surface of the cooler 9, so that the range (region) that is expanded during reflow is limited. That is, it expands inside the opening 101 of the solder resist 10. Due to the solder resist 10, the bonding material 8 is restricted in diffusion and gathers at the peripheral corners of the conductor layer 3, so that the exposed portion of the side surface portion 32 of the conductor layer 3 can be reliably covered.
　また、ソルダーレジスト１０を形成したことで、導体層３の角部においても、接合材８が十分に供給される。そのため、この角部においても、接合材８のテーパー（フィレット）形状が形成し易くなる。 Further, since the solder resist 10 is formed, the bonding material 8 is sufficiently supplied also at the corners of the conductor layer 3. Therefore, it becomes easy to form the taper (fillet) shape of the bonding material 8 also in this corner portion.
　次に、上記の製造工程で作製されたパワーモジュール３００について、説明する。 Next, the power module 300 produced in the above manufacturing process will be described.
　図２０は、この発明の実施の形態２におけるパワーモジュールのソルダーレジスト形状を示す平面構造模式図である。図２１は、この発明の実施の形態２におけるパワーモジュールの角部を示す断面構造模式図である。図において、導体層３を点線で示している。 FIG. 20 is a schematic plan view showing the solder resist shape of the power module according to Embodiment 2 of the present invention. FIG. 21 is a schematic cross-sectional structure diagram showing a corner portion of the power module according to Embodiment 2 of the present invention. In the figure, the conductor layer 3 is indicated by a dotted line.
　図２０に示すように、ソルダーレジスト１０は、内側の一辺が２１ｍｍの寸法で中央領域が開口している。そして、導体層３の辺部分とソルダーレジスト１０の辺部との間隔は２.５ｍｍである。 As shown in FIG. 20, the solder resist 10 has a dimension of 21 mm on the inner side and an opening in the central region. The distance between the side portion of the conductor layer 3 and the side portion of the solder resist 10 is 2.5 mm.
　絶縁回路基板４の下面側の導体層３と冷却器９との接合は、接合材８として実施の形態１と同様に大きさが１６ｍｍ×１６ｍｍ、厚さが０.３ｍｍのフィルム状のはんだを使用して、冷却器９の所定位置に、絶縁回路基板４の下面側の導体層３とフィルム状のはんだとを治具で固定して、加熱することにより実施した。 For joining the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the cooler 9, a film-like solder having a size of 16 mm × 16 mm and a thickness of 0.3 mm is used as the bonding material 8 as in the first embodiment. It was implemented by fixing the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the film-like solder to a predetermined position of the cooler 9 with a jig and heating.
　絶縁回路基板４の下面側の導体層３と冷却器９との接合後、絶縁回路基板４の下面側の導体層３と冷却器９との間のはんだ厚は０.２５ｍｍとなるように調整しているため、はんだが絶縁回路基板４の下面側の導体層３の露出した平面部３１からはみ出し、導体層３の側面部３２の０.５ｍｍ露出した部分に沿ってはんだのテーパーが形成された。 After joining the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9, the solder thickness between the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 is adjusted to be 0.25 mm. Therefore, the solder protrudes from the exposed flat portion 31 of the conductor layer 3 on the lower surface side of the insulated circuit board 4, and a taper of the solder is formed along the exposed portion of the side surface portion 32 of the conductor layer 3 by 0.5 mm. It was.
　図２１には、絶縁回路基板４の下面側の導体層３と冷却器９との接合後の露出した導体層３の側面部３２の角部（コーナー部）のテーパー形状を観察した結果を示す。図において、モールド樹脂７または接合材８に覆われている部分の導体層３を点線で示している。大きさが１６ｍｍ×１６ｍｍ、厚さが０.３ｍｍのフィルム状のはんだが０.２５ｍｍの厚さまで押し潰される時には、はんだは円形状に広がって行く。 In FIG. 21, the result of having observed the taper shape of the corner | angular part (corner part) of the side part 32 of the exposed conductor layer 3 after joining the conductor layer 3 of the lower surface side of the insulated circuit board 4 and the cooler 9 is shown. . In the drawing, a portion of the conductor layer 3 covered with the mold resin 7 or the bonding material 8 is indicated by a dotted line. When a film-like solder having a size of 16 mm × 16 mm and a thickness of 0.3 mm is crushed to a thickness of 0.25 mm, the solder spreads in a circular shape.
　ソルダーレジスト１０を形成しない場合は、はんだの拡がりを規制できないため、導体層３の角部へのはんだの供給量が少なく角部でのテーパー高さが低くなる傾向にある。しかしながら、ソルダーレジスト１０を形成したことで、ソルダーレジスト１０がはんだに対してダムの役割をしてほぼ正方形の形ではんだが拡がる。その結果、露出した導体層３の角部にもはんだが回り込むので、テーパー高さを確保することが可能となる。そして、パワーモジュール３００の信頼性が向上する。 When the solder resist 10 is not formed, the spread of the solder cannot be regulated, so that the amount of solder supplied to the corner of the conductor layer 3 is small and the taper height at the corner tends to be low. However, since the solder resist 10 is formed, the solder resist 10 acts as a dam with respect to the solder, and the solder spreads in a substantially square shape. As a result, since the solder also wraps around the exposed corners of the conductor layer 3, it is possible to ensure a taper height. And the reliability of the power module 300 improves.
　図２２は、この発明の実施の形態２におけるパワーモジュールの他のソルダーレジスト形状を示す平面構造模式図である。図２３は、この発明の実施の形態２におけるパワーモジュールの他のソルダーレジスト形状を示す平面構造模式図である。図２４は、この発明の実施の形態２におけるパワーモジュールの他の角部を示す断面構造模式図である。図において、導体層３を点線で示している。 FIG. 22 is a schematic plan view showing another solder resist shape of the power module according to Embodiment 2 of the present invention. FIG. 23 is a schematic plan view showing another solder resist shape of the power module according to Embodiment 2 of the present invention. FIG. 24 is a schematic cross-sectional structure diagram showing another corner portion of the power module according to Embodiment 2 of the present invention. In the figure, the conductor layer 3 is indicated by a dotted line.
　図２２において、ソルダーレジスト１０は、内側の一辺が１８ｍｍの寸法で中央領域が開口している。ソルダーレジスト１０の接合材８と対向する角部において内側から外側へ向かう開口が拡がった突出部（内側から外側へ尖った）を備えている。導体層３の辺部分とソルダーレジスト１０の辺部との間隔は１.０ｍｍである。 Referring to FIG. 22, the solder resist 10 has an inner side dimension of 18 mm and an opening in the central region. In the corner portion of the solder resist 10 facing the bonding material 8, there is provided a projecting portion (pointed from the inside to the outside) in which the opening from the inside toward the outside widens. The distance between the side portion of the conductor layer 3 and the side portion of the solder resist 10 is 1.0 mm.
　ソルダーレジスト１０の突出部の形状は、図２２に示したような先端が尖った形状だけでなく、図２３に示すように、先端が丸い形状（曲率を持たせた形状）であってもよい。はんだは、ソルダーレジスト１０の開口部の形状で成形される。このため、ソルダーレジスト１０の開口部の突出部の先端を丸い形状とすることで、温度サイクル試験時にはんだに作用する熱応力を緩和可能となりパワーモジュール３００の信頼性が向上する。 The shape of the protruding portion of the solder resist 10 is not limited to a shape with a sharp tip as shown in FIG. 22, but may have a round shape (a shape with a curvature) as shown in FIG. . The solder is formed in the shape of the opening of the solder resist 10. For this reason, by making the tip of the protruding portion of the opening of the solder resist 10 round, it is possible to relieve the thermal stress acting on the solder during the temperature cycle test, and the reliability of the power module 300 is improved.
　絶縁回路基板４の下面側の導体層３と冷却器９との接合は、実施の形態１と同様に大きさが１６ｍｍ×１６ｍｍ、厚さが０.３ｍｍのフィルム状のはんだを使用して、冷却器９の所定位置に、絶縁回路基板４の下面側の導体層３とフィルム状のはんだとを治具で固定して、加熱することにより実施した。 As in the first embodiment, the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the cooler 9 are joined using film-like solder having a size of 16 mm × 16 mm and a thickness of 0.3 mm. The conductor layer 3 on the lower surface side of the insulating circuit board 4 and the film-like solder were fixed with a jig at a predetermined position of the cooler 9 and heated.
　絶縁回路基板４の下面側の導体層３と冷却器９との接合後、絶縁回路基板４の下面側の導体層３と冷却器９との間のはんだ厚は０.２５ｍｍとなるように調整しているため、はんだが絶縁回路基板４の下面側の導体層３の露出した平面部３１から外側へはみ出し、導体層３の側面部３２の０.５ｍｍ露出した部分に沿ってはんだのテーパー形成となった。 After joining the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9, the solder thickness between the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9 is adjusted to be 0.25 mm. Therefore, the solder protrudes outward from the exposed flat portion 31 of the conductor layer 3 on the lower surface side of the insulated circuit board 4, and forms a taper of the solder along the exposed portion of the side surface portion 32 of the conductor layer 3 by 0.5 mm. It became.
　図２４には、絶縁回路基板４の下面側の導体層３と冷却器９との接合後の露出した導体層３の角部（コーナー部）のテーパー形状を観察した結果を示す。図において、モールド樹脂７または接合材８に覆われている部分の導体層３を点線で示している。大きさが１６ｍｍ×１６ｍｍ、厚さが０.３ｍｍのフィルム状のはんだが、０.２５ｍｍの厚まで押し潰される時に、はんだは円形状に広がって行く。しかしながら、ソルダーレジスト１０を形成したことで、ソルダーレジスト１０がはんだに対してダムの役割をしてほぼ正方形の形ではんだが広がる。 FIG. 24 shows the result of observing the tapered shape of the corner (corner portion) of the exposed conductor layer 3 after joining the conductor layer 3 on the lower surface side of the insulated circuit board 4 and the cooler 9. In the drawing, a portion of the conductor layer 3 covered with the mold resin 7 or the bonding material 8 is indicated by a dotted line. When a film-like solder having a size of 16 mm × 16 mm and a thickness of 0.3 mm is crushed to a thickness of 0.25 mm, the solder spreads in a circular shape. However, since the solder resist 10 is formed, the solder resist 10 acts as a dam with respect to the solder, and the solder spreads in a substantially square shape.
　このため、はんだは、導体層３の露出した角部にも回り込む。さらに、図２２、図２３に示したようにソルダーレジスト１０の内側の角部近傍においては、突出部を設けた形状をしていることで、さらにこの突出部へはんだが回り込み、均一な高さのテーパーが形成可能となる。つまり、導体層３の側面部３２におけるはんだの高さが高く形成される（導体層３が形成されている絶縁基板１の下面側に近づく）。そのため、温度サイクル試験時に熱応力が最大となる導体層コーナー部のテーパー高さが確保されているので、テーパーの応力緩和効果ではんだの剥離が防止可能となりパワーモジュール３００の信頼性が向上する。 Therefore, the solder also wraps around the exposed corner of the conductor layer 3. Further, as shown in FIG. 22 and FIG. 23, in the vicinity of the inner corner of the solder resist 10, since the protrusion is provided, the solder further wraps around the protrusion, and the uniform height. Can be formed. That is, the height of the solder in the side surface portion 32 of the conductor layer 3 is formed high (closer to the lower surface side of the insulating substrate 1 on which the conductor layer 3 is formed). Therefore, since the taper height of the conductor layer corner portion where the thermal stress is maximized during the temperature cycle test is secured, it is possible to prevent the peeling of the solder due to the stress relaxation effect of the taper, and the reliability of the power module 300 is improved.
　このことより、均一な高さのテーパーを形成するためには、導体層３の外形よりも１.０ｍｍ程度大きな形状でソルダーレジスト１０の開口形状とすることが好ましい。 For this reason, in order to form a taper having a uniform height, it is preferable that the opening shape of the solder resist 10 be a shape approximately 1.0 mm larger than the outer shape of the conductor layer 3.
　図２５は、この発明の実施の形態２における他のパワーモジュールを示す平面構造模式図である。図において、パワーモジュール４００は、冷却器９の上に２つのモールド樹脂７で封止された絶縁回路基板４を備えている。それぞれの絶縁回路基板４の下面側の導体層３の外周部には、ソルダーレジスト１０が形成されている。このように、冷却器９の大きさを調整することで、複数個のモールド樹脂７で封止された絶縁回路基板４を配置することが可能となる。 FIG. 25 is a schematic plan view showing another power module according to Embodiment 2 of the present invention. In the figure, a power module 400 includes an insulated circuit board 4 sealed with two mold resins 7 on a cooler 9. A solder resist 10 is formed on the outer periphery of the conductor layer 3 on the lower surface side of each insulating circuit board 4. In this way, by adjusting the size of the cooler 9, it is possible to arrange the insulated circuit board 4 sealed with a plurality of mold resins 7.
　以上のように構成されたパワーモジュールにおいては、モールド樹脂７で封止された絶縁回路基板４の下面側の導体層３の側面部３２の一部もモールド樹脂７で封止し、モールド樹脂７から露出した導体層３の平面部３１と側面部３２と冷却器９とを接合材８で接合したので、この金属接合部での剥離の発生が抑制できる。その結果、パワーモジュールの信頼性を向上させることが可能となる。 In the power module configured as described above, a part of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit board 4 sealed with the mold resin 7 is also sealed with the mold resin 7. Since the planar portion 31, the side surface portion 32, and the cooler 9 of the conductor layer 3 exposed from the above are joined by the joining material 8, it is possible to suppress the occurrence of peeling at the metal joining portion. As a result, it becomes possible to improve the reliability of the power module.
　また、モールド樹脂７から露出した導体層３の平面部３１と側面部３２と冷却器９とを接合材８で接合した接合部の形状をテーパー形状としたので、金属接合部での熱応力の発生が抑制でき、パワーモジュールの信頼性を向上させることが可能となる。 Further, since the shape of the joint portion obtained by joining the flat portion 31, the side surface portion 32, and the cooler 9 of the conductor layer 3 exposed from the mold resin 7 with the joining material 8 is a tapered shape, the thermal stress at the metal joint portion is reduced. Generation | occurrence | production can be suppressed and it becomes possible to improve the reliability of a power module.
　さらに、ソルダーレジスト１０を用いることで、導体層３の角部においてもテーパー形状を形成することができ、金属接合部での熱応力の発生が抑制でき、パワーモジュールの信頼性を向上させることが可能となる。 Furthermore, by using the solder resist 10, it is possible to form a tapered shape also at the corners of the conductor layer 3, to suppress the generation of thermal stress at the metal joint, and to improve the reliability of the power module. It becomes possible.
　また、冷却器９の上面に形成するソルダーレジスト１０の形状を、ソルダーレジスト１０の角部を内部側から外部側へ突出した突出部を備えた形状としたので、導体層３の角部においても高さが均一なテーパー形状を形成することができ、金属接合部での熱応力の発生が抑制でき、パワーモジュールの信頼性を向上させることが可能となる。 Moreover, since the shape of the solder resist 10 formed on the upper surface of the cooler 9 is a shape provided with a protruding portion in which the corner portion of the solder resist 10 protrudes from the inner side to the outer side, A taper shape with a uniform height can be formed, generation of thermal stress at the metal joint can be suppressed, and the reliability of the power module can be improved.
実施の形態３．
　本実施の形態３においては、実施の形態１，２で用いた電極端子６において、パワーモジュールの上面側からモールド樹脂７外部へ突出させた点が異なる。このように、電極端子６をモールド樹脂７の上面側から突出させたので、絶縁回路基板４の下面側の導体層３と冷却器９との信頼性を確保したまま、パワーモジュールの小型化が可能となる。なお、その他の点については、実施の形態１または実施の形態２と同様であるので、詳しい説明は省略する。 Embodiment 3 FIG.
The third embodiment is different in that the electrode terminal 6 used in the first and second embodiments is protruded from the upper surface side of the power module to the outside of the mold resin 7. Thus, since the electrode terminal 6 is protruded from the upper surface side of the mold resin 7, the power module can be downsized while the reliability of the conductor layer 3 on the lower surface side of the insulating circuit board 4 and the cooler 9 is ensured. It becomes possible. Since other points are the same as those in the first embodiment or the second embodiment, detailed description thereof is omitted.
　図２６は、この発明の実施の形態３におけるパワーモジュールを示す平面構造模式図である。図２７は、この発明の実施の形態３におけるパワーモジュールを示す断面構造模式図である。図２６中の一点鎖線ＣＣにおける断面構造模式図が図２７である。図において、パワーモジュール５００は、絶縁回路基板４、半導体素子５、電極端子６、モールド樹脂７、接合材８、冷却器９、ソルダーレジスト１０を備えている。 FIG. 26 is a schematic plan view showing a power module according to Embodiment 3 of the present invention. FIG. 27 is a schematic cross-sectional structure diagram showing a power module according to Embodiment 3 of the present invention. FIG. 27 is a schematic cross-sectional view taken along the alternate long and short dash line CC in FIG. In the figure, a power module 500 includes an insulating circuit board 4, a semiconductor element 5, an electrode terminal 6, a mold resin 7, a bonding material 8, a cooler 9, and a solder resist 10.
　電極端子６がモールド樹脂７の上面側から外部へ突出した上出し構造になっている以外は、実施の形態２と同じ構造である。 The structure is the same as that of the second embodiment except that the electrode terminal 6 has a protruding structure protruding from the upper surface side of the mold resin 7 to the outside.
　図２７に示すように、電極端子６が上出し構造でのモールド樹脂封止は、例えば、上金型に電極端子６の収納用のキャビティーを形成しておき、そこに電極端子６を挿入して行う。モールド樹脂７の硬化後、電極端子６を所定の形状に加工する。他の工程は、実施の形態２と同様にして、パワーモジュール５００を作製できる。また、実施の形態１のように、ソルダーレジスト１０を用いないパワーモジュールの構造についても実現可能である。このような構造としたので、絶縁回路基板４の下面側の導体層３と冷却器９と接合部の信頼性を確保したまま、パワーモジュールの小型化が可能となる。 As shown in FIG. 27, the mold resin sealing with the electrode terminal 6 protruding upward is performed by, for example, forming a cavity for storing the electrode terminal 6 in the upper mold, and inserting the electrode terminal 6 therein. And do it. After the mold resin 7 is cured, the electrode terminal 6 is processed into a predetermined shape. In other steps, the power module 500 can be manufactured in the same manner as in the second embodiment. Further, as in the first embodiment, a power module structure that does not use the solder resist 10 can be realized. With such a structure, the power module can be reduced in size while ensuring the reliability of the conductor layer 3 on the lower surface side of the insulated circuit board 4, the cooler 9, and the joint.
　以上のように構成されたパワーモジュールにおいては、モールド樹脂７で封止された絶縁回路基板４の下面側の導体層３の側面部３２の一部もモールド樹脂７で封止し、モールド樹脂７から露出した導体層３の平面部３１と側面部３２と冷却器９とを接合材８で接合したので、この金属接合部での剥離の発生が抑制できる。その結果、パワーモジュールの信頼性を向上させることが可能となる。 In the power module configured as described above, a part of the side surface portion 32 of the conductor layer 3 on the lower surface side of the insulating circuit board 4 sealed with the mold resin 7 is also sealed with the mold resin 7. Since the planar portion 31, the side surface portion 32, and the cooler 9 of the conductor layer 3 exposed from the above are joined by the joining material 8, it is possible to suppress the occurrence of peeling at the metal joining portion. As a result, it becomes possible to improve the reliability of the power module.
　また、モールド樹脂７から露出した導体層３の平面部３１と側面部３２と冷却器９とを接合材８で接合した接合部の形状をテーパー形状としたので、金属接合部での熱応力の発生が抑制でき、パワーモジュールの信頼性を向上させることが可能となる。 Further, since the shape of the joint portion obtained by joining the flat portion 31, the side surface portion 32, and the cooler 9 of the conductor layer 3 exposed from the mold resin 7 with the joining material 8 is a tapered shape, the thermal stress at the metal joint portion is reduced. Generation | occurrence | production can be suppressed and it becomes possible to improve the reliability of a power module.
　さらに、ソルダーレジスト１０を用いることで、導体層３の角部においてもテーパー形状を形成することができ、金属接合部での熱応力の発生が抑制でき、パワーモジュールの信頼性を向上させることが可能となる。 Furthermore, by using the solder resist 10, it is possible to form a tapered shape also at the corners of the conductor layer 3, to suppress the generation of thermal stress at the metal joint, and to improve the reliability of the power module. It becomes possible.
　また、冷却器９の上面に形成するソルダーレジスト１０の形状を、ソルダーレジスト１０の角部を外周側へ突出した形状としたので、導体層３の角部においても高さが均一なテーパー形状を形成することができ、金属接合部での熱応力の発生が抑制でき、パワーモジュールの信頼性を向上させることが可能となる。 Moreover, since the shape of the solder resist 10 formed on the upper surface of the cooler 9 is a shape in which the corner portion of the solder resist 10 protrudes to the outer peripheral side, a tapered shape having a uniform height at the corner portion of the conductor layer 3 is also formed. It can be formed, the generation of thermal stress at the metal joint can be suppressed, and the reliability of the power module can be improved.
　さらに、電極端子６をモールド樹脂７の上面側からモールド樹脂７外部へ突出させたので、絶縁回路基板４の下面側の導体層３と冷却器９と接合部の信頼性を確保したまま、パワーモジュールの小型化が可能となる。 Furthermore, since the electrode terminal 6 is protruded from the upper surface side of the mold resin 7 to the outside of the mold resin 7, the power of the conductor layer 3 on the lower surface side of the insulated circuit board 4, the cooler 9, and the joint is ensured. The module can be miniaturized.
実施の形態４．
　本実施の形態４は、上述した実施の形態１から３にかかるパワーモジュールを電力変換装置に適用したものである。本発明は特定の電力変換装置に限定されるものではないが、以下、実施の形態４として、三相のインバータに本発明を適用した場合について説明する。 Embodiment 4 FIG.
In the fourth embodiment, the power module according to the first to third embodiments described above is applied to a power converter. Although the present invention is not limited to a specific power converter, hereinafter, a case where the present invention is applied to a three-phase inverter will be described as a fourth embodiment.
　図２８は、この発明の実施の形態４における電力変換装置を適用した電力変換システムの構成を示すブロック図である。 FIG. 28 is a block diagram showing a configuration of a power conversion system to which the power conversion device according to Embodiment 4 of the present invention is applied.
　図２８に示す電力変換システムは、電源１０００、電力変換装置２０００、負荷３０００を備える。電源１０００は、直流電源であり、電力変換装置２０００に直流電力を供給する。電源１０００は種々のもので構成することが可能であり、例えば、直流系統、太陽電池、蓄電池で構成することができるし、交流系統に接続された整流回路やＡＣ／ＤＣコンバータで構成することとしてもよい。また、電源１０００を、直流系統から出力される直流電力を所定の電力に変換するＤＣ／ＤＣコンバータによって構成することとしてもよい。 28 includes a power supply 1000, a power conversion device 2000, and a load 3000. The power supply 1000 is a DC power supply and supplies DC power to the power converter 2000. The power supply 1000 can be composed of various types. For example, the power source 1000 can be composed of a direct current system, a solar battery, or a storage battery, and can be composed of a rectifier circuit or an AC / DC converter connected to the alternating current system. Also good. The power supply 1000 may be configured by a DC / DC converter that converts DC power output from the DC system into predetermined power.
　電力変換装置２０００は、電源１０００と負荷３０００の間に接続された三相のインバータであり、電源１０００から供給された直流電力を交流電力に変換し、負荷３０００に交流電力を供給する。電力変換装置２０００は、図１３に示すように、電源１０００から入力される直流電力を交流電力に変換して出力する主変換回路２００１と、主変換回路２００１を制御する制御信号を主変換回路２００１に出力する制御回路２００３とを備えている。 The power conversion device 2000 is a three-phase inverter connected between the power supply 1000 and the load 3000, converts DC power supplied from the power supply 1000 into AC power, and supplies AC power to the load 3000. As shown in FIG. 13, the power conversion device 2000 converts a DC power input from the power supply 1000 into an AC power and outputs a main conversion circuit 2001, and a control signal for controlling the main conversion circuit 2001. And a control circuit 2003 for outputting to the computer.
　負荷３０００は、電力変換装置２０００から供給された交流電力によって駆動される三相の電動機である。なお、負荷３０００は特定の用途に限られるものではなく、各種電気機器に搭載された電動機であり、例えば、ハイブリッド自動車や電気自動車、鉄道車両、エレベーター、もしくは、空調機器向けの電動機として用いられる。 The load 3000 is a three-phase motor driven by AC power supplied from the power converter 2000. Note that the load 3000 is not limited to a specific application, and is an electric motor mounted on various electric devices. For example, the load 3000 is used as an electric motor for a hybrid vehicle, an electric vehicle, a railway vehicle, an elevator, or an air conditioner.
　以下、電力変換装置２０００の詳細を説明する。主変換回路２００１は、パワーモジュール２００２に内蔵されたスイッチング素子と還流ダイオードを備えており（図示せず）、スイッチング素子がスイッチングすることによって、電源１０００から供給される直流電力を交流電力に変換し、負荷３０００に供給する。主変換回路２００１の具体的な回路構成は種々のものがあるが、本実施の形態にかかる主変換回路２００１は２レベルの三相フルブリッジ回路であり、６つのスイッチング素子とそれぞれのスイッチング素子に逆並列された６つの還流ダイオードから構成することができる。主変換回路２００１は、各スイッチング素子や各還流ダイオードを内蔵する上述した実施の形態１から３のいずれかに相当するパワーモジュール２００２によって構成する。６つのスイッチング素子は２つのスイッチング素子ごとに直列接続され上下アームを構成し、各上下アームはフルブリッジ回路の各相（Ｕ相、Ｖ相、Ｗ相）を構成する。そして、各上下アームの出力端子、すなわち主変換回路２００１の３つの出力端子は、負荷３０００に接続される。 Hereinafter, details of the power conversion device 2000 will be described. The main conversion circuit 2001 includes a switching element and a free wheel diode (not shown) built in the power module 2002, and converts the DC power supplied from the power supply 1000 into AC power by switching the switching element. The load 3000 is supplied. Although there are various specific circuit configurations of the main conversion circuit 2001, the main conversion circuit 2001 according to the present embodiment is a two-level three-phase full bridge circuit, and includes six switching elements and respective switching elements. It can be composed of six anti-parallel diodes. The main conversion circuit 2001 is configured by a power module 2002 corresponding to any one of the above-described first to third embodiments, in which each switching element and each free-wheeling diode are incorporated. The six switching elements are connected in series for each of the two switching elements to constitute upper and lower arms, and each upper and lower arm constitutes each phase (U phase, V phase, W phase) of the full bridge circuit. The output terminals of the upper and lower arms, that is, the three output terminals of the main conversion circuit 2001 are connected to the load 3000.
　また、主変換回路２００１は、各スイッチング素子を駆動する駆動回路（図示なし）を備えているが、駆動回路はパワーモジュール２００２に内蔵されていてもよいし、パワーモジュール２００２とは別に駆動回路を備える構成であってもよい。駆動回路は、主変換回路２００１のスイッチング素子を駆動する駆動信号を生成し、主変換回路２００１のスイッチング素子の制御電極に供給する。具体的には、後述する制御回路２００３からの制御信号に従い、スイッチング素子をオン状態にする駆動信号とスイッチング素子をオフ状態にする駆動信号とを各スイッチング素子の制御電極に出力する。スイッチング素子をオン状態に維持する場合、駆動信号はスイッチング素子の閾値電圧以上の電圧信号（オン信号）であり、スイッチング素子をオフ状態に維持する場合、駆動信号はスイッチング素子の閾値電圧以下の電圧信号（オフ信号）となる。 The main conversion circuit 2001 includes a drive circuit (not shown) for driving each switching element. However, the drive circuit may be built in the power module 2002 or a drive circuit may be provided separately from the power module 2002. The structure provided may be sufficient. The drive circuit generates a drive signal for driving the switching element of the main conversion circuit 2001 and supplies it to the control electrode of the switching element of the main conversion circuit 2001. Specifically, in accordance with a control signal from a control circuit 2003 described later, a drive signal for turning on the switching element and a drive signal for turning off the switching element are output to the control electrode of each switching element. When the switching element is maintained in the ON state, the drive signal is a voltage signal (ON signal) that is equal to or higher than the threshold voltage of the switching element, and when the switching element is maintained in the OFF state, the drive signal is a voltage that is equal to or lower than the threshold voltage of the switching element. Signal (off signal).
　制御回路２００３は、負荷３０００に所望の電力が供給されるよう主変換回路２００１のスイッチング素子を制御する。具体的には、負荷３０００に供給すべき電力に基づいて主変換回路２００１の各スイッチング素子がオン状態となるべき時間（オン時間）を算出する。例えば、出力すべき電圧に応じてスイッチング素子のオン時間を変調するＰＷＭ制御によって主変換回路２００１を制御することができる。そして、各時点においてオン状態となるべきスイッチング素子にはオン信号を、オフ状態となるべきスイッチング素子にはオフ信号が出力されるよう、主変換回路２００１が備える駆動回路に制御指令（制御信号）を出力する。駆動回路は、この制御信号に従い、各スイッチング素子の制御電極にオン信号又はオフ信号を駆動信号として出力する。 The control circuit 2003 controls the switching element of the main conversion circuit 2001 so that desired power is supplied to the load 3000. Specifically, based on the power to be supplied to the load 3000, the time (ON time) during which each switching element of the main converter circuit 2001 is to be turned on is calculated. For example, the main conversion circuit 2001 can be controlled by PWM control that modulates the ON time of the switching element according to the voltage to be output. Then, a control command (control signal) is supplied to the drive circuit included in the main conversion circuit 2001 so that an ON signal is output to the switching element that should be turned on at each time point and an OFF signal is output to the switching element that should be turned off. Is output. In accordance with this control signal, the drive circuit outputs an ON signal or an OFF signal as a drive signal to the control electrode of each switching element.
　以上のように構成された本実施の形態４に係る電力変換装置においては、主変換回路２００１のパワーモジュール２００２として実施の形態１から３にかかるパワーモジュールを適用するため、信頼性向上を実現することができる。 In the power conversion device according to the fourth embodiment configured as described above, the power module according to the first to third embodiments is applied as the power module 2002 of the main conversion circuit 2001, thereby improving reliability. be able to.
　本実施の形態では、２レベルの三相インバータに本発明を適用する例を説明したが、本発明は、これに限られるものではなく、種々の電力変換装置に適用することができる。本実施の形態では、２レベルの電力変換装置としたが３レベルやマルチレベルの電力変換装置であっても構わないし、単相負荷に電力を供給する場合には単相のインバータに本発明を適用しても構わない。また、直流負荷等に電力を供給する場合にはＤＣ／ＤＣコンバータやＡＣ／ＤＣコンバータに本発明を適用することも可能である。 In this embodiment, an example in which the present invention is applied to a two-level three-phase inverter has been described. However, the present invention is not limited to this, and can be applied to various power conversion devices. In the present embodiment, a two-level power converter is used. However, a three-level or multi-level power converter may be used. When power is supplied to a single-phase load, the present invention is applied to a single-phase inverter. You may apply. In addition, when power is supplied to a direct current load or the like, the present invention can be applied to a DC / DC converter or an AC / DC converter.
　また、本発明を適用した電力変換装置は、上述した負荷が電動機の場合に限定されるものではなく、例えば、放電加工機やレーザー加工機、又は誘導加熱調理器や非接触器給電システムの電源装置として用いることもでき、さらには太陽光発電システムや蓄電システム等のパワーコンディショナーとして用いることも可能である。 In addition, the power conversion device to which the present invention is applied is not limited to the case where the load described above is an electric motor. For example, the power source of an electric discharge machine, a laser processing machine, an induction heating cooker, or a non-contact power supply system It can also be used as a device, and can also be used as a power conditioner for a photovoltaic power generation system, a power storage system, or the like.
　上述した実施の形態は、すべての点で例示であって制限的なものではないと解されるべきである。本発明の範囲は、上述した実施形態の範囲ではなく、特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更を含むものである。 It should be understood that the above-described embodiment is illustrative in all points and not restrictive. The scope of the present invention is shown not by the scope of the above-described embodiment but by the scope of the claims, and includes all modifications within the meaning and scope equivalent to the scope of the claims.
　また、上記の実施形態に開示されている複数の構成要素を適宜組み合わせることにより発明を形成してもよい。 Further, the invention may be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiment.
　１　セラミック板、２，３　導体層、４　絶縁回路基板、５　半導体素子、６　電極端子、７　モールド樹脂、８　接合材、９　冷却器、１０　ソルダーレジスト、１１　上金型、１２　下金型、１３　下金型キャビティー、３１　導体層３の平面部、３２　導体層３の側面部、９１　冷却ピン、１００，２００，３００，４００，５００，２００２　パワーモジュール、１０１　開口部、１０００　電源、２０００　電力変換装置、２００１　主変換回路、２００３　制御回路、３０００　負荷。 1 ceramic plate, 2, 3 conductor layer, 4 insulated circuit board, 5 semiconductor element, 6 electrode terminal, 7 mold resin, 8 bonding material, 9 cooler, 10 solder resist, 11 upper mold, 12 lower mold, 13 Lower mold cavity, 31 plane portion of conductor layer 3, 32 side surface portion of conductor layer 3, 91 cooling pin, 100, 200, 300, 400, 500, 2002 power module, 101 opening, 1000 power source, 2000 power conversion Equipment, 2001 main conversion circuit, 2003 control circuit, 3000 load.

Claims (12)

  1. 上面と下面とに導体層を有し、前記上面の前記導体層上に半導体素子が搭載された絶縁基板と、
    前記下面の前記導体層は下側に平面部、側面に側面部をそれぞれ有し、前記平面部と前記側面部の一部とを露出して前記絶縁基板を封止する封止樹脂と、
    前記封止樹脂から露出した前記平面部と前記側面部の一部とに接合する接合材と、
    前記接合材を介して前記絶縁基板と接合された冷却器と、
    を備えたことを特徴とするパワーモジュール。     An insulating substrate having a conductor layer on an upper surface and a lower surface, and a semiconductor element mounted on the conductor layer on the upper surface;
    The conductive layer on the lower surface has a flat surface portion on the lower side and a side surface portion on the side surface, a sealing resin that seals the insulating substrate by exposing the flat surface portion and a part of the side surface portion;
    A bonding material bonded to the flat portion exposed from the sealing resin and a part of the side surface;
    A cooler bonded to the insulating substrate via the bonding material;
    A power module comprising:
  2. 前記接合材は、前記側面部における形状がテーパー形状であることを特徴とする請求項１に記載のパワーモジュール。 The power module according to claim 1, wherein the bonding material has a tapered shape in the side surface portion.
  3. 前記側面部における形状は、断面視において、前記絶縁基板側の幅よりも前記冷却器側の幅が広いことを特徴とする請求項２に記載のパワーモジュール。 The power module according to claim 2, wherein the shape of the side surface portion is wider on the cooler side than on the insulating substrate side in a sectional view.
  4. 前記上面の前記導体層および前記半導体素子と接続する電極端子を備えたことを特徴とする請求項１から請求項３のいずれか１項に記載のパワーモジュール。 The power module according to any one of claims 1 to 3, further comprising an electrode terminal connected to the conductor layer on the upper surface and the semiconductor element.
  5. 前記電極端子は、前記封止樹脂の側面側から外部へ突出したことを特徴とする請求項４に記載のパワーモジュール。 The power module according to claim 4, wherein the electrode terminal protrudes outward from a side surface side of the sealing resin.
  6. 前記電極端子は、前記封止樹脂の上面側から外部へ突出したことを特徴とする請求項４に記載のパワーモジュール。 The power module according to claim 4, wherein the electrode terminal protrudes from the upper surface side of the sealing resin to the outside.
  7. 前記冷却器の上面で前記接合材の外周部を囲む領域に設けられたソルダーレジストと、
    を備えたことを特徴とする請求項１から請求項６のいずれか１項に記載のパワーモジュール。     A solder resist provided in a region surrounding the outer periphery of the bonding material on the upper surface of the cooler;
    The power module according to any one of claims 1 to 6, further comprising:
  8. 前記ソルダーレジストは、前記接合材の角部と対向する角部において内側から外側へ向かう突出部を備えたことを特徴とする請求項７に記載のパワーモジュール。 The power module according to claim 7, wherein the solder resist includes a protruding portion that extends from the inner side to the outer side at a corner portion facing the corner portion of the bonding material.
  9. 前記導体層の露出した前記側面部の長さをＬ（ｍｍ）とし、前記導体層の厚さをｔ（ｍｍ）としたとき、前記長さＬが、ｔ－０.２≧Ｌ≧１/３×ｔの範囲であることを特徴とする請求項１から請求項８のいずれか１項に記載のパワーモジュール。 When the length of the exposed side surface portion of the conductor layer is L (mm) and the thickness of the conductor layer is t (mm), the length L is t−0.2 ≧ L ≧ 1 / The power module according to claim 1, wherein the power module is in a range of 3 × t.
  10. 上面と下面とに導体層を有する絶縁基板の前記下面の前記導体層の側面の側面部の一部を露出して前記下面の前記導体層を下金型のはめ込み部にはめ込む絶縁回路基板設置工程と、
    前記絶縁基板と露出した前記側面部の一部とを封止樹脂で封止する樹脂封止工程と、
    前記封止樹脂から露出した前記下面の前記導体層の下側の平面部と前記側面部の一部とを接合材を介して冷却器と接合する冷却器接合工程と、
    を備えたことを特徴とするパワーモジュールの製造方法。     Insulating circuit board installation step of exposing a part of the side surface of the side surface of the conductor layer on the lower surface of the insulating substrate having a conductor layer on the upper surface and the lower surface and fitting the conductor layer on the lower surface into the fitting portion of the lower mold When,
    A resin sealing step of sealing the insulating substrate and a part of the exposed side surface portion with a sealing resin;
    A cooler joining step of joining a lower flat portion of the lower surface of the conductive layer exposed from the sealing resin and a part of the side face portion to a cooler via a joining material;
    A method for manufacturing a power module, comprising:
  11. 前記冷却器の上面に開口部を有するソルダーレジストを形成するソルダーレジスト形成工程と、
    を備えたことを特徴とする請求項１０に記載のパワーモジュールの製造方法。     A solder resist forming step of forming a solder resist having an opening on the upper surface of the cooler;
    The method for manufacturing a power module according to claim 10, comprising:
  12. 請求項１から請求項９のいずれか１項に記載のパワーモジュールを有し、入力される電力を変換して出力する主変換回路と、
    前記主変換回路を制御する制御信号を前記主変換回路に出力する制御回路と、
    を備えた電力変換装置。     A main conversion circuit that has the power module according to any one of claims 1 to 9 and converts and outputs input power;
    A control circuit for outputting a control signal for controlling the main conversion circuit to the main conversion circuit;
    The power converter provided with.
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6644196B1 (en) * 2019-02-01 2020-02-12 三菱電機株式会社 Semiconductor device, method of manufacturing the same, and power converter
JP6698965B1 (en) * 2019-06-06 2020-05-27 三菱電機株式会社 Semiconductor device, power converter, and method of manufacturing semiconductor device
JP2020098821A (en) * 2018-12-17 2020-06-25 富士電機株式会社 Semiconductor device and method of manufacturing semiconductor device
JPWO2021220357A1 (en) * 2020-04-27 2021-11-04
WO2022137701A1 (en) * 2020-12-22 2022-06-30 日立Astemo株式会社 Electric circuit element and power converting apparatus

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2023073752A1 (en) * 2021-10-25 2023-05-04 三菱電機株式会社 Semiconductor device, power conversion device, and method for manufacturing semiconductor device
WO2024116873A1 (en) * 2022-11-29 2024-06-06 ローム株式会社 Semiconductor module

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008227336A (en) * 2007-03-15 2008-09-25 Hitachi Metals Ltd Semiconductor module, circuit board used therefor
JP2012129336A (en) * 2010-12-15 2012-07-05 Fuji Electric Co Ltd Semiconductor device and manufacturing method of the same
JP2013225556A (en) * 2012-04-20 2013-10-31 Mitsubishi Electric Corp Semiconductor device and manufacturing method therefor
JP2014146645A (en) * 2013-01-28 2014-08-14 Mitsubishi Electric Corp Semiconductor device
WO2016031462A1 (en) * 2014-08-28 2016-03-03 富士電機株式会社 Power semiconductor module
JP2016092233A (en) * 2014-11-05 2016-05-23 富士電機株式会社 Semiconductor device
WO2016158020A1 (en) * 2015-04-01 2016-10-06 富士電機株式会社 Semiconductor module

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008227336A (en) * 2007-03-15 2008-09-25 Hitachi Metals Ltd Semiconductor module, circuit board used therefor
JP2012129336A (en) * 2010-12-15 2012-07-05 Fuji Electric Co Ltd Semiconductor device and manufacturing method of the same
JP2013225556A (en) * 2012-04-20 2013-10-31 Mitsubishi Electric Corp Semiconductor device and manufacturing method therefor
JP2014146645A (en) * 2013-01-28 2014-08-14 Mitsubishi Electric Corp Semiconductor device
WO2016031462A1 (en) * 2014-08-28 2016-03-03 富士電機株式会社 Power semiconductor module
JP2016092233A (en) * 2014-11-05 2016-05-23 富士電機株式会社 Semiconductor device
WO2016158020A1 (en) * 2015-04-01 2016-10-06 富士電機株式会社 Semiconductor module

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2020098821A (en) * 2018-12-17 2020-06-25 富士電機株式会社 Semiconductor device and method of manufacturing semiconductor device
JP7188049B2 (en) 2018-12-17 2022-12-13 富士電機株式会社 semiconductor equipment
JP6644196B1 (en) * 2019-02-01 2020-02-12 三菱電機株式会社 Semiconductor device, method of manufacturing the same, and power converter
WO2020157965A1 (en) * 2019-02-01 2020-08-06 三菱電機株式会社 Semiconductor device and method for manufacturing same, and power conversion device
JP6698965B1 (en) * 2019-06-06 2020-05-27 三菱電機株式会社 Semiconductor device, power converter, and method of manufacturing semiconductor device
WO2020245998A1 (en) * 2019-06-06 2020-12-10 三菱電機株式会社 Semiconductor device, power conversion device, and manufacturing method of semiconductor device
JPWO2021220357A1 (en) * 2020-04-27 2021-11-04
WO2022137701A1 (en) * 2020-12-22 2022-06-30 日立Astemo株式会社 Electric circuit element and power converting apparatus

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