WO2021111846A1 - Power semiconductor device, and method for manufacturing same - Google Patents

Power semiconductor device, and method for manufacturing same Download PDF

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Publication number
WO2021111846A1
WO2021111846A1 PCT/JP2020/042392 JP2020042392W WO2021111846A1 WO 2021111846 A1 WO2021111846 A1 WO 2021111846A1 JP 2020042392 W JP2020042392 W JP 2020042392W WO 2021111846 A1 WO2021111846 A1 WO 2021111846A1
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WO
WIPO (PCT)
Prior art keywords
terminal portion
power semiconductor
conductive
terminal
semiconductor device
Prior art date
Application number
PCT/JP2020/042392
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French (fr)
Japanese (ja)
Inventor
範之 別芝
公昭 樽谷
啓 林
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to JP2021562544A priority Critical patent/JP7170911B2/en
Priority to CN202080081445.0A priority patent/CN114730751A/en
Publication of WO2021111846A1 publication Critical patent/WO2021111846A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
    • H01L21/50—Assembly of semiconductor devices using processes or apparatus not provided for in a single one of the subgroups H01L21/06 - H01L21/326, e.g. sealing of a cap to a base of a container
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/48—Arrangements for conducting electric current to or from the solid state body in operation, e.g. leads, terminal arrangements ; Selection of materials therefor
    • 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
    • H01L2224/32—Structure, shape, material or disposition of the layer connectors after the connecting process of an individual layer connector
    • H01L2224/321—Disposition
    • H01L2224/32151—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive
    • H01L2224/32221—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked
    • H01L2224/32225—Disposition the layer connector connecting between a semiconductor or solid-state body and an item not being a semiconductor or solid-state body, e.g. chip-to-substrate, chip-to-passive the body and the item being stacked the item being non-metallic, e.g. insulating substrate with or without metallisation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • 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
    • H01L2224/34—Strap connectors, e.g. copper straps for grounding power devices; Manufacturing methods related thereto
    • H01L2224/39—Structure, shape, material or disposition of the strap connectors after the connecting process
    • H01L2224/40—Structure, shape, material or disposition of the strap connectors after the connecting process of an individual strap connector
    • H01L2224/401—Disposition
    • H01L2224/40135—Connecting between different semiconductor or solid-state bodies, i.e. chip-to-chip
    • H01L2224/40137—Connecting between different semiconductor or solid-state bodies, i.e. chip-to-chip the bodies being arranged next to each other, e.g. on a common substrate
    • H01L2224/40139—Connecting between different semiconductor or solid-state bodies, i.e. chip-to-chip the bodies being arranged next to each other, e.g. on a common substrate with an intermediate bond, e.g. continuous strap daisy chain

Definitions

  • This disclosure relates to a power semiconductor device and a manufacturing method thereof.
  • Patent Document 1 includes a power semiconductor element such as an insulated gate bipolar transistor (IGBT), a DCB substrate, a heat dissipation base plate, an insert case, a bus bar, and a lead wire. It discloses a power semiconductor device.
  • the DCB substrate is joined to the heat dissipation base plate.
  • the power semiconductor element is bonded to the DCB substrate.
  • the insert case is joined to the heat dissipation base plate and surrounds the power semiconductor element and the DCB substrate.
  • the insert case is provided with a bus bar.
  • the power semiconductor element is electrically connected to the bus bar via a lead wire. Specifically, one end of the lead wire is joined to the power semiconductor element by using solder. The other end of the lead wire is joined to the bus bar using solder.
  • the purpose of this disclosure is to improve the reliability of power semiconductor devices.
  • the power semiconductor device of the present disclosure includes a substrate, a first power semiconductor element, lead-out wiring, and a plate-shaped terminal.
  • the first power semiconductor element includes a first back surface electrode bonded to the substrate and a first front surface electrode on the opposite side of the first back surface electrode.
  • the plate-shaped terminal includes a first terminal portion and a second terminal portion. The first terminal portion is joined to the first front surface electrode by using the first conductive joining member.
  • the second terminal portion is joined to the lead-out wiring by using the second conductive joining member.
  • the first linear expansion coefficient difference between the first power semiconductor element and the first terminal portion is larger than the second linear expansion coefficient difference between the lead wiring and the second terminal portion.
  • the first terminal portion is thinner than the second terminal portion.
  • the method for manufacturing a power semiconductor device of the present disclosure is to bond the first back electrode of the first power semiconductor element to a substrate, and to attach a plate-shaped terminal to the first power semiconductor element on the side opposite to the first back electrode. 1 It is provided to join the front surface electrode and the lead-out wiring.
  • the plate-shaped terminal includes a first terminal portion and a second terminal portion. The difference in the first linear expansion coefficient between the first power semiconductor element and the first terminal portion is larger than the difference in the second linear expansion coefficient between the lead wiring and the second terminal portion. The first terminal portion is thinner than the second terminal portion. While the first terminal portion is bonded to the first front surface electrode using the first conductive bonding member, the second terminal portion is bonded to the lead-out wiring using the second conductive bonding member.
  • the first conductive joining member is heated by using the first heat source.
  • the first heat source is controlled based on the first temperature of the first terminal portion measured using the first temperature sensor.
  • the second conductive joining member is heated by using the second heat source.
  • the second heat source is controlled based on the second temperature of the second terminal portion measured using the second temperature sensor.
  • the thermal stress applied to the first conductive joining member can be reduced. It is possible to prevent the first conductive joint member from being cracked and the first terminal portion from being separated from the first front surface electrode.
  • the second terminal portion is thicker than the first terminal portion. The second terminal portion has a larger heat capacity than the first terminal portion. Therefore, the temperature rise of the second conductive bonding member can be reduced. Deterioration of the second conductive joint member is reduced. According to the power semiconductor device of the present disclosure, the reliability of the power semiconductor device can be improved. According to the method for manufacturing a power semiconductor device of the present disclosure, a power semiconductor device with improved reliability can be obtained.
  • FIG. It is the schematic sectional drawing of the power semiconductor device which concerns on Embodiment 1.
  • FIG. It is a figure which shows the flowchart of the manufacturing method of the power semiconductor device which concerns on Embodiment 1.
  • FIG. It is a figure which shows the flowchart of the process S4 of the manufacturing method of the power semiconductor device which concerns on Embodiment 1.
  • FIG. It is the schematic which shows the 1st example of the manufacturing apparatus of the power semiconductor apparatus which concerns on Embodiment 1.
  • FIG. It is a block diagram of the 1st example and the 2nd example of the manufacturing apparatus of the power semiconductor apparatus which concerns on Embodiment 1.
  • FIG. It is the schematic which shows the 2nd example of the manufacturing apparatus of the power semiconductor apparatus which concerns on Embodiment 1.
  • FIG. It is the schematic sectional drawing of the power semiconductor device which concerns on Embodiment 2.
  • FIG. It is the schematic sectional drawing of the power semiconductor device which concerns on Embodiment 3.
  • the power semiconductor device 1 of the first embodiment will be described with reference to FIG.
  • the power semiconductor device 1 mainly includes a substrate 10, a first power semiconductor element 20, lead wiring 41, 41 g, and plate-shaped terminals 50, 50 g.
  • the power semiconductor device 1 may further include a terminal block 40 and a heat sink 30.
  • the power semiconductor device 1 may further include a second power semiconductor element 25.
  • the substrate 10 includes an insulating layer 11, a front surface conductor layer 12, and a back surface conductor layer 13.
  • the substrate 10 extends along a first direction (x direction) and a second direction (y direction) orthogonal to the first direction.
  • the third direction (z direction) perpendicular to the first direction (x direction) and the second direction (y direction) is the thickness direction of the substrate 10.
  • the insulating layer 11 is, for example, a ceramic layer such as aluminum nitride (AlN), silicon nitride (Si 3 N 4 ), or alumina (Al 2 O 3 ), or an epoxy resin containing a boron nitride (BN) filler. It is a resin layer.
  • the insulating layer 11 preferably has electrical insulation and high thermal conductivity.
  • the insulating layer 11 has a thickness of, for example, 0.3 mm or more and 1.0 mm.
  • the front surface conductor layer 12 and the back surface conductor layer 13 are, for example, a copper (Cu) layer, an aluminum (Al) layer, or a laminate of Cu and Al.
  • the front surface conductor layer 12 and the back surface conductor layer 13 each have a thickness of, for example, 0.2 mm or more.
  • the front surface conductor layer 12 and the back surface conductor layer 13 may each have a thickness of 0.3 mm or more.
  • the front surface conductor layer 12 and the back surface conductor layer 13 each have a thickness of, for example, 1.0 mm or less.
  • the front surface conductor layer 12 and the back surface conductor layer 13 may each have a thickness of 0.6 mm or less.
  • Front surface The front surface of the conductor layer 12 is the main surface 10a of the substrate 10.
  • the first power semiconductor element 20 and the second power semiconductor element 25 are arranged adjacent to each other in the first direction (x direction).
  • the first power semiconductor element 20 and the second power semiconductor element 25 are made of silicon (Si).
  • the first power semiconductor element 20 and the second power semiconductor element 25 may be formed of a semiconductor material having a band gap larger than that of Si, such as silicon carbide (SiC), gallium nitride (GaN), and diamond.
  • a semiconductor material having a band gap larger than that of Si enables the first power semiconductor element 20 and the second power semiconductor element 25 to operate normally even at a high temperature, and also enables the power semiconductor device 1 to be miniaturized. ..
  • the first power semiconductor element 20 includes a first back surface electrode 22 and a first front surface electrode 21 on the opposite side of the first back surface electrode 22.
  • the first back surface electrode 22 and the first front surface electrode 21 are separated from each other in the thickness direction (third direction (z direction)) of the first power semiconductor element 20.
  • the second power semiconductor element 25 includes a second back surface electrode 27 and a second front surface electrode 26 on the opposite side of the second back surface electrode 27.
  • the second back surface electrode 27 and the second front surface electrode 26 are separated from each other in the thickness direction (third direction (z direction)) of the second power semiconductor element 25.
  • the thickness direction of the first power semiconductor element 20 (third direction (z direction)) and the thickness direction of the second power semiconductor element 25 (third direction (z direction)) are normals of the main surface 10a of the substrate 10. It is parallel to the direction (third direction (z direction)).
  • the first power semiconductor element 20 is an insulated gate bipolar transistor (IGBT), and the second power semiconductor element 25 is a freewheel diode (FWD).
  • the first front surface electrode 21 includes an emitter electrode (not shown) and a gate electrode (not shown), and the first back surface electrode 22 is a collector electrode.
  • the second front surface electrode 26 is an anode electrode.
  • the second back surface electrode 27 is a cathode electrode.
  • the first power semiconductor element 20 and the second power semiconductor element 25 may be other power semiconductor elements such as a metal oxide semiconductor field effect transistor (MOSFET).
  • MOSFET metal oxide semiconductor field effect transistor
  • the first back electrode 22 of the first power semiconductor element 20 is bonded to the front surface conductor layer 12 of the substrate 10 by using the conductive bonding member 23.
  • the second back electrode 27 of the second power semiconductor element 25 is bonded to the front surface conductor layer 12 of the substrate 10 by using the conductive bonding member 28.
  • the conductive bonding member 23 and the conductive bonding member 28 are formed of, for example, a solder such as lead-free solder, silver (Ag), copper (Cu), or a copper tin (CuSn) alloy.
  • the conductive joining member 23 and the conductive joining member 28 have, for example, a melting point of 250 ° C. or higher.
  • the conductive joining member 23 and the conductive joining member 28 may have a melting point of 300 ° C. or higher.
  • the conductive bonding member 23 and the conductive bonding member 28 may be formed of a metal fine particle sintered body such as a silver fine particle sintered body, a copper fine particle sintered body, or a CuSn fine particle sintered body.
  • the fine particles mean particles having a diameter of 100 ⁇ m or less.
  • the fine particles may be particles having a diameter of 10 ⁇ m or less, or may be nanoparticles.
  • the metal fine particle sintered body is obtained by sintering a paste in which metal fine particles are dispersed by utilizing the phenomenon that the metal fine particles are sintered at a temperature lower than the melting point of the metal constituting the fine particles.
  • the metal fine particle sintered body thus obtained has a melting point of the metal constituting the fine particles, and has a higher melting point than that of solder.
  • the metal fine particle sintered body enables the first power semiconductor element 20 and the second power semiconductor element 25 to operate normally even at a high temperature.
  • the metal fine particle sintered body improves the reliability of the power semiconductor device 1 and enables the power semiconductor device 1 to be miniaturized.
  • a first metallized layer (not shown) suitable for diffusion bonding with the first conductive bonding member 55 may be provided on the first front surface electrode 21.
  • a second metallized layer (not shown) suitable for diffusion bonding with the third conductive bonding member 56 may be provided on the second front surface electrode 26.
  • the first metallized layer and the second metallized layer are, for example, a gold (Au) layer and a nickel (Ni) layer from the outermost surface side, respectively. Is a laminated body in which is laminated.
  • the Au layer prevents oxidation of the outermost surfaces of the first front surface electrode 21 and the second front surface electrode 26, and improves the wettability with respect to the solder.
  • the Ni layer prevents the solder from diffusing into the first front surface electrode 21 and the second front surface electrode 26.
  • the thickness of the Ni layer is determined in consideration of the mode of heat application during solder bonding and the maximum temperature during operation of the first power semiconductor element 20 and the second power semiconductor element 25.
  • the Ni layer has, for example, a thickness of 1.5 ⁇ m or more and 5.0 ⁇ m or less.
  • the Ni layer is formed, for example, by sputtering or plating.
  • the lead-out wiring 41 and the plate-shaped terminal 50 electrically connect the first power semiconductor element 20 and the second power semiconductor element 25 to a member outside the power semiconductor device 1.
  • a current or voltage is supplied to the first power semiconductor element 20 and the second power semiconductor element 25 from a member outside the power semiconductor device 1 through the lead-out wiring 41 and the plate-shaped terminal 50, or the first power. It is supplied from the semiconductor element 20 and the second power semiconductor element 25 to a member outside the power semiconductor device 1.
  • the member outside the power semiconductor device 1 is, for example, a motor, and the power semiconductor device 1 is, for example, an inverter for driving a motor. When driving a motor, a current of several hundred amperes flows through the lead-out wiring 41 and the plate-shaped terminal 50.
  • the lead-out wiring 41 and the plate-shaped terminal 50 are formed of a laminate composed of a copper (Cu), copper tungsten (CuW) alloy, or a Cu layer / Invar (Fe-36% Ni alloy) layer / Cu layer, respectively. Has been done.
  • the lead-out wiring 41 and the plate-shaped terminal 50 are made of the same material.
  • the lead-out wiring 41 and the plate-shaped terminal 50 may be made of different materials from each other.
  • the lead-out wiring 41 mainly extends in the second direction (y direction), and the longitudinal direction of the lead-out wiring 41 is the second direction (y direction).
  • the plate-shaped terminal 50 mainly extends in the first direction (x direction) intersecting the lead-out wiring 41, and the longitudinal direction of the plate-shaped terminal 50 is the first direction (x direction).
  • the plate-shaped terminal 50 includes a first terminal portion 51 and a second terminal portion 52.
  • the plate-shaped terminal 50 may further include a third terminal portion 53 that connects the first terminal portion 51 and the second terminal portion 52.
  • the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are made of the same material, and the plate-shaped terminal 50 is composed of a single component.
  • the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are separate parts from each other, and the first terminal portion 51 and the second terminal Higher than the plate-shaped terminals 50 formed by connecting the portions 52 to each other, for example by soldering or welding, and connecting the second terminal portion 52 and the third terminal portion 53 to each other, for example by soldering or welding. Has reliability.
  • the plate-shaped terminal 50 may be composed of a plurality of parts.
  • the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are separate parts from each other, and the first terminal portion 51 and the second terminal portion 52 are connected to each other by, for example, soldering or welding.
  • the second terminal portion 52 and the third terminal portion 53 may be connected to each other by, for example, soldering or welding. Therefore, even if the plate-shaped terminal 50 has a complicated shape such as a crank shape in a plan view from the thickness direction (third direction (z direction)) of the substrate 10, the plate-shaped terminal 50 can be used. It can be formed with a relatively high yield and a relatively low cost.
  • the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are separate parts, the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are made of the same material. It may be formed of materials different from each other.
  • the first terminal portion 51 extends in the first direction (x direction), and the longitudinal direction of the first terminal portion 51 is the first direction (x direction).
  • the first terminal portion 51 extends along the main surface 10a of the substrate 10.
  • the second terminal portion 52 extends in the first direction (x direction), and the longitudinal direction of the second terminal portion 52 is the first direction (x direction).
  • the second terminal portion 52 extends along the main surface 10a of the substrate 10.
  • the third terminal portion 53 extends in the third direction (z direction), and the longitudinal direction of the third terminal portion 53 is the third direction (z direction).
  • the third terminal portion 53 extends along the thickness direction (third direction (z direction)) of the first power semiconductor element 20.
  • the distance between the first terminal portion 51 and the main surface 10a of the substrate 10 in the thickness direction of the first power semiconductor element 20 is the thickness direction of the first power semiconductor element 20 (the third direction (z direction)). It is shorter than the distance between the second terminal portion 52 and the main surface 10a of the substrate 10 in the third direction (z direction).
  • the first terminal portion 51 is thinner than the second terminal portion 52. Specifically, the ratio of the first thickness t 1 of the first terminal portion 51 to the second thickness t 2 of the second terminal portion 52 is 0.75 or less. This ratio may be 0.60 or less. The ratio of the first thickness t 1 of the first terminal portion 51 to the second thickness t 2 of the second terminal portion 52 is 0.10 or more. This ratio may be 0.20 or more.
  • the third terminal portion 53 is thinner than the second terminal portion 52. Specifically, the ratio of the third thickness t 3 of the third terminal portion 53 to the second thickness t 2 of the second terminal portion 52 is 0.75 or less. This ratio may be 0.60 or less. The ratio of the third thickness t 3 of the third terminal portion 53 to the second thickness t 2 of the second terminal portion 52 is 0.10 or more. This ratio may be 0.20 or more.
  • the first thickness t 1 of the first terminal portion 51 is 0.60 mm or less.
  • the first thickness t 1 may be 0.50 mm or less.
  • the first thickness t 1 of the first terminal portion 51 is, for example, 0.15 mm or more.
  • the first thickness t 1 may be 0.20 mm or more.
  • the second thickness t 2 of the second terminal portion 52 is, for example, 0.80 mm or more.
  • the second thickness t 2 may be 1.0 mm or more.
  • the second thickness t 2 of the second terminal portion 52 is, for example, 1.50 mm or less.
  • the second thickness t 2 of the second terminal portion 52 may be 1.35 mm or less.
  • the third thickness t 3 of the third terminal portion 53 is, for example, 0.60 mm or less.
  • the third thickness t 3 may be 0.50 mm or less.
  • the third thickness t 3 of the third terminal portion 53 is, for example, 0.15 mm or more.
  • the third thickness t 3 may be 0.20 mm or more.
  • the third thickness t 3 of the third terminal portion 53 may be equal to the first thickness t 1 of the first terminal portion 51.
  • the first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52.
  • the third linear expansion coefficient difference between the second power semiconductor element 25 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52.
  • Both the first power semiconductor element 20 and the second power semiconductor element 25 arranged adjacent to each other are joined to one plate-shaped terminal 50. Therefore, the wiring inductance can be reduced, and the surge voltage applied to the first power semiconductor element 20 and the second power semiconductor element 25 can be reduced. Further, the joining of the plate-shaped terminal 50 and the first power semiconductor element 20 and the joining of the plate-shaped terminal 50 and the second power semiconductor element 25 can be performed in one step. The productivity of the power semiconductor device 1 is improved.
  • the first terminal portion 51 is joined to the first front surface electrode 21 by using the first conductive joining member 55.
  • the second terminal portion 52 is joined to the lead-out wiring 41 by using the second conductive joining member 57.
  • the first terminal portion 51 is bonded to the second front surface electrode 26 by using the third conductive bonding member 56.
  • the second conductive joining member 57 may be formed of the same material as the first conductive joining member 55 and the third conductive joining member 56, or may be made of a different material from the first conductive joining member 55 and the third conductive joining member 56. It may be formed.
  • the first conductive bonding member 55, the second conductive bonding member 57, and the third conductive bonding member 56 are formed of, for example, a solder such as lead-free solder, silver (Ag), copper (Cu), or a copper tin (CuSn) alloy. Has been done.
  • the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 have a melting point of 250 ° C. or higher.
  • the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 may have a melting point of 300 ° C. or higher.
  • the first conductive bonding member 55 is a first solder containing Sn as a main component.
  • the first solder has a 0.2% proof stress higher than that of Sn.
  • the first solder is, for example, Sn—Cu-based solder or Sn—Sb-based solder.
  • the second conductive bonding member 57 is a second solder containing Sn as a main component.
  • the second solder has a higher thermal conductivity than Sn.
  • the second solder is, for example, Sn-Au-based solder or Sn-Ag-based solder.
  • the third conductive bonding member 56 is formed of a third solder containing Sn as a main component.
  • the third solder has a 0.2% proof stress higher than that of Sn.
  • the third solder is, for example, Sn—Cu-based solder or Sn—Sb-based solder.
  • the first conductive joining member 55 and the third conductive joining member 56 have a higher 0.2% proof stress than the second conductive joining member 57.
  • the second conductive joint member 57 has a higher thermal conductivity than the first conductive joint member 55 and the third conductive joint member 56.
  • the first conductive bonding member 55, the second conductive bonding member 57, and the third conductive bonding member 56 are formed of a metal fine particle sintered body such as a silver fine particle sintered body, a copper fine particle sintered body, or a CuSn fine particle sintered body. You may.
  • the metal fine particle sintered body is obtained by sintering a paste in which metal fine particles are dispersed by utilizing the phenomenon that the metal fine particles are sintered at a temperature lower than the melting point of the metal constituting the fine particles.
  • the metal fine particle sintered body thus obtained has a melting point of the metal constituting the fine particles, and has a higher melting point than that of solder.
  • the metal fine particle sintered body enables the first power semiconductor element 20 and the second power semiconductor element 25 to operate normally even at a high temperature.
  • the metal fine particle sintered body improves the reliability of the power semiconductor device 1 and enables the power semiconductor device 1 to be miniaturized.
  • the terminal block 40 is made of a heat-resistant insulating resin such as polyphenylene sulfide (PPS) or liquid crystal polymer (LCP).
  • the thermal conductivity of the terminal block 40 is smaller than the thermal conductivity of the lead-out wiring 41 and smaller than the thermal conductivity of the plate-shaped terminal 50.
  • the thermal conductivity of the terminal block 40 is smaller than the thermal conductivity of the first power semiconductor element 20 and smaller than the thermal conductivity of the second power semiconductor element 25.
  • the thermal conductivity of the terminal block 40 is, for example, 1.0 W / mK or less.
  • a part of the lead-out wiring 41 is embedded in the terminal block 40.
  • the rest of the lead-out wiring 41 is exposed from the terminal block 40.
  • the second terminal portion 52 of the plate-shaped terminal 50 is joined to the portion of the lead-out wiring 41 exposed from the terminal block 40 by using the second conductive joining member 57.
  • the lead-out wiring 41g is configured in the same manner as the lead-out wiring 41.
  • the lead-out wiring 41g extends in the second direction (y direction), and the longitudinal direction of the lead-out wiring 41g is the second direction (y direction).
  • a part of the lead-out wiring 41 g is embedded in the terminal block 40.
  • the rest of the lead-out wiring 41 g is exposed from the terminal block 40.
  • the lead-out wiring 41g is electrically insulated from the lead-out wiring 41 by the insulating resin constituting the terminal block 40.
  • the plate-shaped terminal 50g is configured in the same manner as the plate-shaped terminal 50.
  • the plate-shaped terminal 50g extends mainly in the first direction (x direction) intersecting the lead-out wiring 41g, and the longitudinal direction of the plate-shaped terminal 50g is the first direction (x direction).
  • One end of the plate-shaped terminal 50g is connected to a portion of the lead-out wiring 41g exposed from the terminal block 40 via a conductive joining member (not shown).
  • the other end of the plate-shaped terminal 50g is connected to the front surface conductor layer 12 of the substrate 10 via a conductive bonding member (not shown).
  • the heat sink 30 dissipates the heat generated by the first power semiconductor element 20 and the second power semiconductor element 25 to the outside of the power semiconductor device 1.
  • the heat sink 30 is made of a material having a high thermal conductivity, for example, copper (Cu) or aluminum (Al).
  • the heat sink 30 is preferably made of Al in order to reduce the weight of the automobile and improve fuel efficiency.
  • the heat sink 30 includes a top plate 31, a plurality of heat radiation fins 32, and a jacket 33.
  • a flow path 36 for the refrigerant 37 is formed between the top plate 31 and the jacket 33.
  • the plurality of heat radiation fins 32 are attached to the back surface of the top plate 31 that defines a part of the flow path 36, and are arranged in the flow path 36.
  • the top plate 31 and the jacket 33 are provided with an inlet 34 and an outlet 35 of the flow path 36.
  • the refrigerant 37 is, for example, water.
  • the refrigerant 37 flows from the radiator (not shown) to the inlet 34 of the flow path 36.
  • the refrigerant 37 flows through the flow path 36 and flows from the outlet 35 of the flow path 36 to the radiator.
  • the refrigerant 37 circulates in the radiator and the heat sink 30.
  • the top plate 31 is liquid-tightly attached to the jacket 33 in order to prevent the refrigerant 37 from leaking from the heat sink 30.
  • a rubber O-ring may be interposed between the top plate 31 and the jacket 33, and the top plate 31 and the jacket 33 may be fixed to each other with screws.
  • a sealing material may be applied between the top plate 31 and the jacket 33, and the top plate 31 and the jacket 33 may be fixed to each other with screws.
  • the top plate 31 and the jacket 33 may be brazed to each other.
  • the top plate 31 and the jacket 33 may be friction stir welded to each other.
  • the board 10 is attached to the heat sink 30.
  • the back surface conductor layer 13 of the substrate 10 is attached to the top plate 31 of the heat sink 30 by using the joining member 14.
  • the joining member 14 is, for example, an aluminum silicon (AlSi) brazing material or a solder containing Sn as a main component.
  • AlSi aluminum silicon
  • the heat-resistant 30 is a plating layer (for example, Ni plating layer or Sn plating layer) capable of forming an alloy with Sn-based solder. May be applied in advance. Since this plating layer is easily alloyed with Sn-based solder, it is easy to join the Sn-based solder and the heat sink 30 made of Al.
  • This plating layer has, for example, a thickness of 2 ⁇ m or more and 10 ⁇ m or less, and realizes good solder wettability and high bonding reliability.
  • the coefficient of linear expansion of the heat sink 30 is given by the coefficient of linear expansion of Al (23 ppm / K).
  • the substrate 10 has an insulating layer 11 made of Si 3 N 4 having a thickness of 0.32 mm, a front surface conductor layer 12 made of a Cu plate having a thickness of 0.50 mm, and the like.
  • the linear expansion coefficient of the substrate 10 is about 7 ppm / K or more and about 8 ppm / K or less. Therefore, the difference in linear expansion coefficient between the substrate 10 and the heat sink 30 becomes large.
  • a joining member having a large 0.2% proof stress can reduce the crack growth rate (crack growth amount per load cycle) of the joining member 14.
  • the terminal block 40 is attached to the heat sink 30. Specifically, the terminal block 40 is attached to the top plate 31 of the heat sink 30 using a silicone-based adhesive or screws.
  • the manufacturing method of the power semiconductor device 1 of the present embodiment includes joining the first power semiconductor element 20 and the second power semiconductor element 25 on the substrate 10 (S1). Specifically, the conductive bonding member 23 is used to bond the first back electrode 22 of the first power semiconductor element 20 to the front surface conductor layer 12 of the substrate 10. The second back electrode 27 of the second power semiconductor element 25 is joined to the front surface conductor layer 12 of the substrate 10 by using the conductive bonding member 28.
  • the manufacturing method of the power semiconductor device 1 of the present embodiment includes attaching the terminal block 40 to the heat sink 30 (S2). Specifically, for example, the terminal block 40 is attached to the top plate 31 of the heat sink 30 using a silicone-based adhesive or screws. A part of the lead-out wiring 41, 41 g is embedded in the terminal block 40. The rest of the lead-out wiring 41, 41 g is exposed from the terminal block 40.
  • the manufacturing method of the power semiconductor device 1 of the present embodiment includes joining the substrate 10 to the heat sink 30 (S3). Specifically, the back surface conductor layer 13 of the substrate 10 is attached to the heat sink 30 by using the joining member 14.
  • the joining member 14 is, for example, an aluminum silicon (AlSi) brazing material or a solder containing Sn as a main component.
  • the plate-shaped terminal 50 is joined to the first power semiconductor element 20, the second power semiconductor element 25, and the lead-out wiring 41 ( S4) is provided.
  • the first conductive bonding member 55, the second conductive bonding member 57, and the third conductive bonding member 56 are each the first front surface of the first power semiconductor element 20. It is placed on the second front surface electrode 26 of the second power semiconductor element 25 on the electrode 21 and on the portion of the lead-out wiring 41 exposed from the terminal block 40 (S41).
  • Bulk solder materials such as bar solder, plate solder, and sheet solder may be used for the first conductive joint member 55, the second conductive joint member 57, and the third conductive joint member 56. By using the bulk solder material, the amount of solder can be adjusted accurately.
  • the bulk solder material may be a fluxless solder material. By using the fluxless solder material, the step of cleaning the flux residue after soldering becomes unnecessary.
  • the plate-shaped terminal 50 is placed on the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 (S42).
  • the plate-shaped terminal 50 includes a first terminal portion 51 and a second terminal portion 52.
  • the plate-shaped terminal 50 may further include a third terminal portion 53 that connects the first terminal portion 51 and the second terminal portion 52.
  • the first terminal portion 51 is thinner than the second terminal portion 52.
  • the third terminal portion 53 is thinner than the second terminal portion 52.
  • the plate-shaped terminal 50 is obtained, for example, by the following steps. Prepare a conductive metal plate with a uniform thickness. Of the conductive metal plate, the portions corresponding to the first terminal portion 51 and the third terminal portion 53 are selectively etched. Then, the conductive metal plate is pressed. In this way, a plate-shaped terminal 50 including the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 can be obtained.
  • the first terminal portion 51 is placed on the first conductive joining member 55 and the third conductive joining member 56.
  • the second terminal portion 52 is placed on the second conductive joining member 57.
  • the difference in the first linear expansion coefficient between the first power semiconductor element 20 and the first terminal portion 51 is larger than the difference in the second linear expansion coefficient between the lead wiring 41 and the second terminal portion 52. ..
  • the difference in the third linear expansion coefficient between the second power semiconductor element 25 and the first terminal portion 51 is larger than the difference in the second linear expansion coefficient between the lead wiring 41 and the second terminal portion 52. ..
  • the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are heated (S43).
  • the first terminal portion 51 By heating the first terminal portion 51, the first conductive joint member 55 and the third conductive joint member 56 are heated, and by heating the second terminal portion 52, the second conductive joint member 57 is heated. You may. Specifically, the second conductive joining member 57 (or the second terminal portion 52) is heated while heating the first conductive joining member 55 and the third conductive joining member 56 (or the first terminal portion 51).
  • the first conductive joining member 55 and the third conductive joining member 56 is performed independently of the heating of the second conductive joining member 57 (or the second terminal portion 52).
  • the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are, for example, lead-free solder.
  • the first conductive bonding member 55 is a first solder containing Sn as a main component.
  • the first solder has a 0.2% proof stress higher than that of Sn.
  • the first solder is, for example, Sn—Cu-based solder or Sn—Sb-based solder.
  • the second conductive bonding member 57 is a second solder containing Sn as a main component.
  • the second solder has a higher thermal conductivity than Sn.
  • the second solder is, for example, Sn-Au-based solder or Sn-Ag-based solder.
  • the third conductive bonding member 56 is a third solder containing Sn as a main component.
  • the third solder has a 0.2% proof stress higher than that of Sn.
  • the third solder is, for example, Sn—Cu-based solder or Sn—Sb-based solder.
  • the first conductive joining member 55 and the third conductive joining member 56 each have a 0.2% proof stress higher than that of the second conductive joining member 57.
  • the second conductive joint member 57 has a higher thermal conductivity than each of the first conductive joint member 55 and the third conductive joint member 56.
  • the member 56 is, for example, a radiant heat method using infrared rays emitted from an infrared light source such as a halogen lamp (see FIGS. 4 and 5) or a heat transfer method using a heat block (see FIGS. 5 and 6). Is heated by.
  • an infrared light source such as a halogen lamp
  • a heat transfer method using a heat block see FIGS. 5 and 6. Is heated by.
  • the emissivity of the plate-shaped terminal 50 is 0.3 or more, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 (see FIGS.
  • the first terminal portion 51 and the second terminal portion 52 are heated.
  • the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are subjected to a heat transfer method (see FIGS. 5 and 6). (1st terminal portion 51 and 2nd terminal portion 52) are heated.
  • the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are heated by using the first heating device 60 shown in FIGS. 4 and 5.
  • the first heating device 60 includes a first heat source 61, a second heat source 62, a first temperature sensor 63, a second temperature sensor 64, and a control unit 65.
  • the first heat source 61 is, for example, a first infrared heater.
  • the second heat source 62 is, for example, a second infrared heater.
  • the first heat source 61 heats the first terminal portion 51 of the plate-shaped terminal 50 to heat the first conductive joint member 55 and the third conductive joint member 56.
  • the second heat source 62 heats the second terminal portion 52 of the plate-shaped terminal 50 to heat the second conductive bonding member 57.
  • the first temperature sensor 63 is a first radiation thermometer.
  • the second temperature sensor 64 is a second radiation thermometer.
  • the first temperature sensor 63 is separated from the plate-shaped terminal 50.
  • the first temperature sensor 63 measures the first temperature of the first terminal portion 51 of the plate-shaped terminal 50.
  • the first temperature sensor 63 indirectly measures the temperature of the first conductive joint member 55 and the temperature of the third conductive joint member 56.
  • the second temperature sensor 64 is separated from the plate-shaped terminal 50.
  • the second temperature sensor 64 measures the second temperature of the second terminal portion 52 of the plate-shaped terminal 50.
  • the second temperature sensor 64 indirectly measures the temperature of the second conductive joint member 57. Since the emissivity of the plate-shaped terminal 50 is 0.3 or more, the first temperature of the first terminal portion 51 and the second temperature of the second terminal portion 52 are used by using the first radiation thermometer and the second radiation thermometer. 2 Temperature can be measured accurately.
  • the control unit 65 is communicably connected to the first heat source 61, the second heat source 62, the first temperature sensor 63, and the second temperature sensor 64.
  • the control unit 65 controls the first heat source 61 based on the first temperature of the first terminal portion 51 measured by using the first temperature sensor 63.
  • the control unit 65 controls the second heat source 62 based on the second temperature of the second terminal portion 52 measured by using the second temperature sensor 64.
  • the first terminal portion 51 is heated by using the first heat source 61, and the first conductive joining member 55 comes into contact with the first terminal portion 51. And the third conductive bonding member 56 is heated.
  • the first heat source 61 is controlled based on the first temperature of the first terminal portion 51 measured by using the first temperature sensor 63.
  • the second terminal portion 52 is heated by using the second heat source 62, and the second conductive joining member 57 in contact with the second terminal portion 52 is heated.
  • the second heat source 62 is controlled based on the second temperature of the second terminal portion 52 measured using the second temperature sensor 64.
  • the second heating device 60b includes a first heat source 61b, a second heat source 62b, a first temperature sensor 63b, a second temperature sensor 64b, and a control unit 65.
  • the first heat source 61b is, for example, a first heat block.
  • the second heat source 62b is, for example, a second heat block.
  • the first heat source 61b heats the first terminal portion 51 of the plate-shaped terminal 50 to heat the first conductive bonding member 55 and the third conductive bonding member 56.
  • the second heat source 62b heats the second terminal portion 52 of the plate-shaped terminal 50 to heat the second conductive bonding member 57.
  • the first temperature sensor 63b is a first contact type thermometer.
  • the second temperature sensor 64b is a second contact thermometer.
  • the first temperature sensor 63b contacts the first terminal portion 51 of the plate-shaped terminal 50 and measures the first temperature of the first terminal portion 51.
  • the first temperature sensor 63b indirectly measures the temperature of the first conductive joining member 55 and the temperature of the third conductive joining member 56.
  • the second temperature sensor 64b contacts the second terminal portion 52 of the plate-shaped terminal 50 and measures the second temperature of the second terminal portion 52.
  • the second temperature sensor 64b indirectly measures the temperature of the second conductive joint member 57. Since the first contact thermometer contacts the first terminal portion 51 and the second contact thermometer contacts the second terminal portion 52, the emissivity of the plate-shaped terminal 50 is less than 0.3. Also, the first temperature of the first terminal portion 51 and the second temperature of the second terminal portion 52 can be accurately measured by using the first contact type thermometer and the second contact type thermometer.
  • the control unit 65 is communicably connected to the first heat source 61b, the second heat source 62b, the first temperature sensor 63b, and the second temperature sensor 64b.
  • the control unit 65 controls the first heat source 61b based on the first temperature of the first terminal portion 51 measured by using the first temperature sensor 63b.
  • the control unit 65 controls the second heat source 62b based on the second temperature of the second terminal portion 52 measured by using the second temperature sensor 64b.
  • the first terminal portion 51 is heated by using the first heat source 61b, and the first conductive joining member 55 comes into contact with the first terminal portion 51. And the third conductive bonding member 56 is heated.
  • the first heat source 61b is controlled based on the first temperature of the first terminal portion 51 measured using the first temperature sensor 63b.
  • the second terminal portion 52 is heated by using the second heat source 62b, and the second conductive joining member 57 in contact with the second terminal portion 52 is heated.
  • the second heat source 62b is controlled based on the second temperature of the second terminal portion 52 measured using the second temperature sensor 64b.
  • the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are cooled (S44).
  • the second terminal portion 51 is joined to the first front surface electrode 21 and the second front surface electrode 26 by using the first conductive bonding member 55 and the third conductive bonding member 56.
  • 52 is joined to the lead-out wiring 41 by using the second conductive joining member 57.
  • the plate-shaped terminal 50 is joined to the first front surface electrode 21 of the first power semiconductor element 20, the second front surface electrode 26 of the second power semiconductor element 25, and the lead-out wiring 41.
  • the plate-shaped terminal 50 g is the front surface conductor layer 12 and the lead-out wiring 41 g. Is joined to.
  • the method of joining the plate-shaped terminal 50 g to the front conductor layer 12 and the lead-out wiring 41 g is a method of joining the plate-shaped terminal 50 to the first power semiconductor element 20, the second power semiconductor element 25, and the lead-out wiring 41. The same is true.
  • the first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52. Greater than the difference.
  • the third linear expansion coefficient difference between the second power semiconductor element 25 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52.
  • the first power semiconductor element 20 and the second power semiconductor element 25 are mainly formed of Si (coefficient of linear expansion 2.5 ppm / K), and the plate-shaped terminal 50 and the lead-out wiring 41 are Cu (linear expansion).
  • the first linear expansion coefficient difference and the third linear expansion coefficient difference are 14.3 ppm / K, respectively, whereas the second linear expansion coefficient difference is It is zero. Therefore, the thermal stress applied to the first conductive bonding member 55 is larger than the thermal stress applied to the second conductive bonding member 57.
  • the thermal stress applied to the third conductive joint member 56 is larger than the thermal stress applied to the second conductive joint member 57.
  • a large thermal stress is repeatedly applied to the first conductive bonding member 55 and the third conductive bonding member 56.
  • the cross-sectional area of the conductive joining member means the area of the conductive joining member in the cross section parallel to the main surface 10a of the substrate 10. Due to the decrease in the cross-sectional area of the first conductive joining member 55 and the cross-sectional area of the third conductive joining member 56, the electric resistance of the first conductive joining member 55 and the electric resistance of the third conductive joining member 56 increase, and the first conductive Joule heat generated by the joining member 55 and the third conductive joining member 56 increases.
  • the thermal stress applied to the first conductive joint member 55 and the third conductive joint member 56 is further increased. Cracks may further develop in the first conductive joint member 55 and the third conductive joint member 56, and the first conductive joint member 55 and the third conductive joint member 56 may be completely torn.
  • a high potential difference is generated between the first front surface electrode 21 of the first power semiconductor element 20 and the lead-out wiring 41, and the first 1
  • An arc discharge is generated between the front surface electrode 21 and the lead-out wiring 41.
  • a high potential difference is generated between the second front surface electrode 26 of the second power semiconductor element 25 and the lead-out wiring 41, and an arc discharge is generated between the second front surface electrode 26 and the lead-out wiring 41.
  • the power semiconductor device 1 fails.
  • the first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the thermal stress applied to the first conductive joining member 55 and the third conductive joining member 56 can be reduced. Cracks occur in the first conductive joint member 55 and the third conductive joint member 56, and the first terminal portion 51 is separated from the first front surface electrode 21 and the second front surface electrode 26. Is prevented.
  • the heat generated in the first power semiconductor element 20 and the second power semiconductor element 25 is transferred to the second conductive bonding member 57 via the plate-shaped terminal 50. Therefore, the temperature of the second conductive joining member 57 rises.
  • the second conductive joining member 57 is in contact with the lead-out wiring 41, and a part of the lead-out wiring 41 is embedded in the terminal block 40 made of insulating resin. Therefore, the temperature of the second conductive bonding member 57 tends to rise. When the temperature of the second conductive joint member 57 rises, the second conductive joint member 57 deteriorates.
  • the second terminal portion 52 is thicker than the first terminal portion 51.
  • the second terminal portion 52 has a larger heat capacity than the first terminal portion 51. Therefore, the temperature rise of the second conductive bonding member 57 can be reduced. Deterioration of the second conductive joint member 57 is reduced.
  • the power semiconductor device 1 of the present embodiment includes a substrate 10, a first power semiconductor element 20, a lead-out wiring 41, and a plate-shaped terminal 50.
  • the first power semiconductor element 20 includes a first back surface electrode 22 bonded to the substrate 10 and a first front surface electrode 21 on the opposite side of the first back surface electrode 22.
  • the plate-shaped terminal 50 includes a first terminal portion 51 and a second terminal portion 52.
  • the first terminal portion 51 is bonded to the first front surface electrode 21 by using the first conductive bonding member 55.
  • the second terminal portion 52 is joined to the lead-out wiring 41 by using the second conductive joining member 57.
  • the first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52.
  • the first terminal portion 51 is thinner than the second terminal portion 52.
  • the first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52. Therefore, the thermal stress applied to the first conductive bonding member 55 is larger than the thermal stress applied to the second conductive bonding member 57.
  • the first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the thermal stress applied to the first conductive bonding member 55 can be reduced. It is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21.
  • the second terminal portion 52 is thicker than the first terminal portion 51.
  • the second terminal portion 52 has a larger heat capacity than the first terminal portion 51. Therefore, the temperature rise of the second conductive joint member 57 is reduced, and the deterioration of the second conductive joint member 57 is reduced. The reliability of the power semiconductor device 1 can be improved.
  • the ratio of the first thickness t 1 of the first terminal portion 51 to the second thickness t 2 of the second terminal portion 52 is 0.10 or more and 0.75 or less. Since this ratio is 0.75 or less, the thermal stress applied to the first conductive bonding member 55 can be reduced. Since this ratio is 0.10 or more, heat generation of the first terminal portion 51 due to the electric resistance of the first terminal portion 51 can be reduced. The temperature rise of the first conductive joining member 55 can be reduced, and the deterioration of the first conductive joining member 55 is reduced. The reliability of the power semiconductor device 1 can be improved.
  • the first thickness t 1 of the first terminal portion 51 is 0.15 mm or more and 0.60 mm or less.
  • the second thickness t 2 of the second terminal portion 52 is 0.80 mm or more and 1.50 mm or less.
  • the thermal stress applied to the first conductive joint member 55 can be reduced. It is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21. Since the first thickness t 1 of the first terminal portion 51 is 0.15 mm or more, heat generation of the first terminal portion 51 due to the electric resistance of the first terminal portion 51 can be reduced. The temperature rise of the first conductive joining member 55 can be reduced, and the deterioration of the first conductive joining member 55 is reduced.
  • the second thickness t 2 of the second terminal portion 52 is 0.80 mm or more, the temperature rise of the second conductive joint member 57 can be reduced, and the deterioration of the second conductive joint member 57 is reduced. .. Since the second thickness t 2 of the second terminal portion 52 is 1.50 mm or less, the mechanical strain applied from the second terminal portion 52 to the second conductive joint member 57 can be reduced. The reliability of the power semiconductor device 1 can be improved.
  • the first conductive bonding member 55 is formed of a metal fine particle sintered body.
  • the metal fine particle sintered body has a high melting point of the metal constituting the fine particles. Therefore, even if the first power semiconductor element 20 operates at a high temperature, the deterioration of the first conductive bonding member 55 is reduced. The reliability of the power semiconductor device 1 can be improved.
  • the first conductive bonding member 55 is the first solder containing Sn as a main component.
  • the first solder has a 0.2% proof stress higher than that of Sn.
  • the second conductive bonding member 57 is a second solder containing Sn as a main component.
  • the second solder has a higher thermal conductivity than Sn.
  • the first conductive joining member 55 has a higher 0.2% proof stress than the second conductive joining member 57. Therefore, it is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21.
  • the second conductive joint member 57 has a higher thermal conductivity than the first conductive joint member 55. Therefore, the temperature rise of the second conductive joining member 57 can be reduced, and the deterioration of the second conductive joining member 57 is reduced. The reliability of the power semiconductor device 1 can be improved.
  • first conductive joining member 55 and the second conductive joining member 57 are common in that they are solders containing Sn as a main component. Therefore, the first terminal portion 51 using the first conductive joining member 55 and the first front surface electrode 21 are joined, and the second terminal portion 52 using the second conductive joining member 57 and the lead-out wiring 41 are joined. Joining can be formed in the same process.
  • the power semiconductor device 1 has a configuration capable of improving the productivity of the power semiconductor device 1.
  • the lead-out wiring 41 further includes a third terminal portion 53 that connects the first terminal portion 51 and the second terminal portion 52.
  • the third terminal portion 53 is formed along the thickness direction (third direction (z direction)) of the first power semiconductor element 20 in which the first back surface electrode 22 and the first front surface electrode 21 are separated from each other. It is postponed.
  • the plate-shaped terminal is caused by the fact that the height of the first front surface electrode 21 in the thickness direction (third direction (z direction)) of the first power semiconductor element 20 is different from the height of the lead-out wiring 41.
  • the mechanical stress applied to the first conductive joining member 55 and the second conductive joining member 57 from 50 is reduced. Cracks occur in the first conductive joint member 55 and the second conductive joint member 57, the first terminal portion 51 is separated from the first front surface electrode 21, and the second terminal portion 52 is a lead-out wiring. It is prevented from peeling off from 41.
  • the reliability of the power semiconductor device 1 can be improved.
  • the power semiconductor device 1 of the present embodiment further includes a terminal block 40 made of an insulating resin. A part of the lead-out wiring 41 is embedded in the terminal block 40. The second terminal portion 52 is joined to the portion of the lead-out wiring 41 exposed from the terminal block 40 by using the second conductive joining member 57. The thermal conductivity of the terminal block 40 is smaller than the thermal conductivity of the lead-out wiring 41 and smaller than the thermal conductivity of the plate-shaped terminal 50.
  • a part of the lead-out wiring 41 is embedded in the terminal block 40 having a relatively low thermal conductivity. Therefore, the temperature of the second conductive joining member 57 joined to the lead-out wiring 41 tends to rise.
  • the second terminal portion 52 is thicker than the first terminal portion 51. Therefore, the temperature rise of the second conductive joining member 57 can be reduced, and the deterioration of the second conductive joining member 57 is reduced. The reliability of the power semiconductor device 1 can be improved.
  • the power semiconductor device 1 of the present embodiment further includes a second power semiconductor element 25.
  • the second power semiconductor element 25 includes a second back surface electrode 27 bonded to the substrate 10 and a second front surface electrode 26 on the opposite side of the second back surface electrode 27.
  • the first terminal portion 51 is bonded to the second front surface electrode 26 by using the third conductive bonding member 56.
  • the third linear expansion coefficient difference between the second power semiconductor element 25 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52.
  • the third linear expansion coefficient difference between the second power semiconductor element 25 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead-out wiring 41 and the second terminal portion 52. Therefore, the thermal stress applied to the third conductive joint member 56 is larger than the thermal stress applied to the second conductive joint member 57.
  • the first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the thermal stress applied to the third conductive joint member 56 can be reduced. It is possible to prevent the third conductive bonding member 56 from being cracked and the first terminal portion 51 from being separated from the second front surface electrode 26. The reliability of the power semiconductor device 1 can be improved.
  • both the first power semiconductor element 20 and the second power semiconductor element 25 are joined to one plate-shaped terminal 50. Therefore, the wiring inductance can be reduced, and the surge voltage applied to the first power semiconductor element 20 and the second power semiconductor element 25 can be reduced. Further, the joining of the plate-shaped terminal 50 and the first power semiconductor element 20 and the joining of the plate-shaped terminal 50 and the second power semiconductor element 25 can be performed in one step.
  • the power semiconductor device 1 has a structure capable of improving the productivity of the power semiconductor device 1.
  • the first back electrode 22 of the first power semiconductor element 20 is bonded to the substrate 10 (S1), and the plate-shaped terminal 50 is attached to the first back electrode 22. Is provided with joining (S4) to the first front surface electrode 21 of the first power semiconductor element 20 on the opposite side and the lead-out wiring 41.
  • the plate-shaped terminal 50 includes a first terminal portion 51 and a second terminal portion 52. The difference in the first linear expansion coefficient between the first power semiconductor element 20 and the first terminal portion 51 is larger than the difference in the second linear expansion coefficient between the lead wiring 41 and the second terminal portion 52. ..
  • the first terminal portion 51 is thinner than the second terminal portion 52.
  • the second terminal portion 52 is bonded to the lead-out wiring 41 using the second conductive bonding member 57. ..
  • the first conductive joining member 55 is heated by using the first heat sources 61 and 61b.
  • the first heat sources 61 and 61b are controlled based on the first temperature of the first terminal portion 51 measured using the first temperature sensors 63 and 63b.
  • the second conductive joining member 57 is heated by using the second heat sources 62 and 62b.
  • the second heat sources 62 and 62b are controlled based on the second temperature of the second terminal portion 52 measured using the second temperature sensors 64 and 64b.
  • the first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52. Therefore, the thermal stress applied to the first conductive bonding member 55 is larger than the thermal stress applied to the second conductive bonding member 57.
  • the first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the thermal stress applied to the first conductive bonding member 55 can be reduced. It is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21.
  • the second terminal portion 52 is thicker than the first terminal portion 51. The second terminal portion 52 has a larger heat capacity than the first terminal portion 51.
  • the temperature rise of the second conductive joining member 57 can be reduced, and the deterioration of the second conductive joining member 57 is reduced. According to the method for manufacturing the power semiconductor device 1 of the present embodiment, the power semiconductor device 1 with improved reliability can be obtained.
  • the second terminal portion 52 is thicker than the first terminal portion 51.
  • the second heat capacity of the second terminal portion 52 is larger than the first heat capacity of the first terminal portion 51.
  • the temperature of the second terminal portion 52 is less likely to rise than that of the first terminal portion 51. Therefore, the connection between the lead-out wiring 41 using the second conductive joining member 57 and the second terminal portion 52 may be poor.
  • the first conductive bonding member 55 in contact with the first terminal portion 51 is heated by using the first heat sources 61 and 61b, and the second terminal portion 52
  • the second conductive bonding member 57 in contact with the first heat source 61, 61b is heated by using a second heat source 62, 62b different from the first heat sources 61, 61b.
  • the first heat sources 61, 61b are controlled based on the first temperature of the first terminal portion 51 measured by using the first temperature sensors 63, 63b
  • the second heat sources 62, 62b are controlled. It is controlled based on the second temperature of the second terminal portion 52 measured by using the second temperature sensors 64, 64b different from the first temperature sensors 63, 63b.
  • the second temperature of the second terminal portion 52 is measured independently of the first temperature of the first terminal portion 51, and is the second.
  • the terminal portion 52 is heated independently of the first terminal portion 51. Therefore, even if the second terminal portion 52 is thicker than the first terminal portion 51, the first conductive joining member 55 in contact with the first terminal portion 51 and the second conductive joining member 57 in contact with the second terminal portion 52 are Can be heated properly.
  • the first front surface electrode 21 and the first terminal portion 51 are satisfactorily joined to each other by using the first conductive joining member 55, and the lead-out wiring 41 and the second terminal portion 52 are joined to each other by the second conductive joining member 57. Are well joined to each other using. According to the method for manufacturing the power semiconductor device 1 of the present embodiment, the power semiconductor device 1 with improved reliability can be obtained.
  • the first conductive bonding member 55 is a first solder containing Sn as a main component.
  • the first solder has a 0.2% proof stress higher than that of Sn.
  • the second conductive bonding member 57 is a second solder containing Sn as a main component.
  • the second solder has a higher thermal conductivity than Sn.
  • the first conductive joining member 55 has a higher 0.2% proof stress than the second conductive joining member 57. Therefore, it is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21. Further, the second conductive joining member 57 has a higher thermal conductivity than the first conductive joining member 55. Therefore, the temperature rise of the second conductive joining member 57 can be reduced, and the deterioration of the second conductive joining member 57 is reduced. According to the method for manufacturing the power semiconductor device 1 of the present embodiment, the power semiconductor device 1 with improved reliability can be obtained.
  • first conductive joining member 55 and the second conductive joining member 57 are common in that they are solders containing Sn as a main component. Therefore, the first terminal portion 51 using the first conductive joining member 55 and the first front surface electrode 21 are joined, and the second terminal portion 52 using the second conductive joining member 57 and the lead-out wiring 41 are joined. Joining can be formed in the same process. According to the method for manufacturing the power semiconductor device 1 of the present embodiment, the power semiconductor device 1 can be obtained with improved productivity.
  • Embodiment 2 The power semiconductor device 1b of the second embodiment will be described with reference to FIG. 7.
  • the power semiconductor device 1b of the present embodiment has the same configuration as the power semiconductor device 1 of the first embodiment, but is mainly different in the following points.
  • the second terminal portion 52b is a folded portion of the conductive metal plate constituting the plate-shaped terminal 50b.
  • the second terminal portion 52b is formed, for example, by folding a conductive metal plate having a uniform thickness one or more times.
  • the second terminal portion 52b may be formed by folding a conductive metal plate having a uniform thickness two or more times.
  • the manufacturing method of the power semiconductor device 1b of the present embodiment includes the same steps as the manufacturing method of the power semiconductor device 1 of the first embodiment, but differs in the manufacturing process of the plate-shaped terminal 50b.
  • the plate-shaped terminal 50b is obtained by, for example, the following steps. Prepare a conductive metal plate with a uniform thickness. The conductive metal plate is press-processed to obtain a plate-shaped terminal 50b including the first terminal portion 51, the second terminal portion 52b, and the third terminal portion 53. The second terminal portion 52b is formed by folding the conductive metal plate one or more times.
  • the power semiconductor device 1b of the present embodiment and the manufacturing method thereof exert the following effects in addition to the effects of the power semiconductor device 1 of the first embodiment and the manufacturing method thereof.
  • the second terminal portion 52b is a folded portion of a conductive metal plate constituting the plate-shaped terminal 50b.
  • the step of partially reducing the thickness of the conductive metal plate constituting the plate-shaped terminal 50b becomes unnecessary. Further, in the present embodiment, it is sufficient to prepare a conductive metal plate thinner than that of the first embodiment as the conductive metal plate constituting the plate-shaped terminal 50b. Therefore, the cost of the plate-shaped terminal 50b is reduced. The cost of the power semiconductor device 1b can be reduced.
  • Embodiment 3 The power semiconductor device 1c of the third embodiment will be described with reference to FIG.
  • the power semiconductor device 1c of the present embodiment has the same configuration as the power semiconductor device 1 of the first embodiment, but is mainly different in the following points.
  • a spring portion 54 is provided at the third terminal portion 53.
  • the spring portion 54 is formed by bending a conductive metal plate constituting the plate-shaped terminal 50c.
  • the spring portion 54 is obtained, for example, by pressing a conductive metal plate.
  • the manufacturing method of the power semiconductor device 1c of the present embodiment includes the same steps as the manufacturing method of the power semiconductor device 1 of the first embodiment, but is mainly different in the following two points.
  • the plate-shaped terminal 50c is obtained by the following steps. Prepare a conductive metal plate with a uniform thickness. The conductive metal plate is press-processed to obtain a plate-shaped terminal 50c including the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53. A spring portion 54 is formed in the third terminal portion 53. The spring portion 54 is formed by bending a conductive metal plate.
  • the plate-shaped terminal 50c is joined to the first power semiconductor element 20, the second power semiconductor element 25, and the lead-out wiring 41 (S4), the plate-shaped terminal 50c is connected to the first front surface electrode 21, Tilt with respect to the second front surface electrode 26 and the lead-out wiring 41 is more reliably prevented.
  • the first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the position of the center of gravity of the plate-shaped terminal 50c is proximal to the second terminal portion 52 and distal to the first terminal portion 51. That is, the position of the center of gravity of the plate-shaped terminal 50c is proximal to the second conductive joining member 57 and distal to the first conductive joining member 55 and the third conductive joining member 56.
  • the plate-shaped terminal 50c is joined to the first power semiconductor element 20, the second power semiconductor element 25, and the lead-out wiring 41 (S4), the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining are joined.
  • the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 become a liquid phase.
  • the thickness of the first conductive joining member 55, the second due to the weight of the plate-shaped terminal 50c.
  • the thickness of the conductive bonding member 57 and the thickness of the third conductive bonding member 56 can be changed.
  • the thickness of the second conductive joint portion proximal to the center of gravity of the plate-shaped terminal 50c decreases, the thickness of the first conductive joint portion distal to the center of gravity of the plate-shaped terminal 50c and the plate shape.
  • the thickness of the third conductive joint distal to the center of gravity of the terminal 50c may increase.
  • the plate-shaped terminal 50c may be tilted with respect to the first front surface electrode 21, the second front surface electrode 26, and the lead-out wiring 41.
  • the first conductive joining member 55 and the third conductive joining member 56 extend in the thickness direction (third direction (z direction)) of the first power semiconductor element 20, and the cross-sectional area of the first conductive joining member 55 and the first 3
  • the cross-sectional area of the conductive joining member 56 is reduced.
  • the joining strength of the first conductive joining member 55 and the joining strength of the third conductive joining member 56 after cooling the first conductive joining member 55 and the third conductive joining member 56 may be insufficient.
  • the thickness of the second conductive joint member 57 after cooling the second conductive joint member 57 may be remarkably reduced, and a large mechanical strain may be applied from the plate-shaped terminal 50c to the second conductive joint member 57. is there.
  • the first terminal portion 51 and the second terminal portion 52 are independent of each other in the thickness direction of the first power semiconductor element 20 (third direction (z direction)). Allows you to move to. Therefore, even if the position of the center of gravity of the plate-shaped terminal 50c is biased toward the second terminal portion 52, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are heated to become a liquid phase. At this time, the plate-shaped terminal 50c is prevented from being tilted with respect to the first front surface electrode 21, the second front surface electrode 26, and the lead-out wiring 41.
  • the cross-sectional area of the first conductive joining member 55 and the cross-sectional area of the third conductive joining member 56 are reduced, so that the joining strength of the first conductive joining member 55 and the joining strength of the third conductive joining member 56 are increased. Can be reliably prevented from decreasing.
  • the spring portion 54 can surely prevent a large mechanical strain from being applied to the second conductive joint member 57.
  • the power semiconductor device 1c of the present embodiment and the manufacturing method thereof have the same effects as the power semiconductor device 1 of the first embodiment and the manufacturing method thereof, but are mainly different in the following points.
  • the third terminal portion 53 is provided with a spring portion 54 formed by bending a conductive metal plate constituting the plate-shaped terminal 50c.
  • the cross-sectional area of the first conductive joining member 55 and the cross-sectional area of the third conductive joining member 56 are reduced, so that the joining strength of the first conductive joining member 55 and the joining strength of the third conductive joining member 56 are increased. Can be reliably prevented from decreasing.
  • the spring portion 54 can surely prevent a large mechanical strain from being applied to the second conductive joint member 57. The reliability of the power semiconductor device 1c can be improved.
  • 1,1b, 1c power semiconductor device 10 substrate, 10a main surface, 11 insulating layer, 12 front surface conductor layer, 13 back surface conductor layer, 14 bonding member, 20 first power semiconductor element, 21 first front surface Surface electrode, 22 1st back surface electrode, 23, 28 conductive bonding member, 25 2nd power semiconductor element, 26 2nd front surface electrode, 27 2nd back surface electrode, 30 heat sink, 31 top plate, 32 heat dissipation fin, 33 Jacket, 34 inlet, 35 outlet, 36 flow path, 37 refrigerant, 40 terminal block, 41,41 g lead-out wiring, 50, 50b, 50c, 50 g plate-shaped terminal, 51 first terminal part, 52, 52b second terminal part, 53 3rd terminal part, 54 spring part, 55 1st conductive joining member, 56 3rd conductive joining member, 57 2nd conductive joining member, 60 1st heating device, 60b 2nd heating device, 61, 61b 1st heat source, 62, 62b second heat source, 63, 63b first temperature

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Abstract

A power semiconductor device (1) comprises a first power semiconductor element (20), lead-out wiring (41), and a plate-shaped terminal (50). The plate-shaped terminal (50) includes a first terminal portion (51) and a second terminal portion (52). The first terminal portion (51) is joined to a first obverse surface electrode (21) of the first power semiconductor element (20). The second terminal portion (52) is joined to the lead-out wiring (41). A first linear expansion coefficient difference between the first power semiconductor element (20) and the first terminal portion (51) is greater than a second linear expansion coefficient difference between the lead-out wiring (41) and the second terminal portion (52). The first terminal portion (51) is thinner than the second terminal portion (52).

Description

パワー半導体装置及びその製造方法Power semiconductor devices and their manufacturing methods
　本開示は、パワー半導体装置及びその製造方法に関する。 This disclosure relates to a power semiconductor device and a manufacturing method thereof.
　特開２０１４－１１２３６号公報（特許文献１）は、絶縁ゲートバイポーラトランジスタ（ＩＧＢＴ）のようなパワー半導体素子と、ＤＣＢ基板と、放熱用ベース板と、インサートケース、バスバーと、リード線とを備えるパワー半導体装置を開示している。ＤＣＢ基板は、放熱用ベース板に接合されている。パワー半導体素子は、ＤＣＢ基板に接合されている。インサートケースは放熱用ベース板に接合されており、パワー半導体素子及びＤＣＢ基板を囲んでいる。インサートケースには、バスバーが設けられている。パワー半導体素子は、リード線を介して、バスバーに電気的に接続されている。具体的には、リード線の一端は、はんだを用いて、パワー半導体素子に接合されている。リード線の他端は、はんだを用いて、バスバーに接合されている。 Japanese Unexamined Patent Publication No. 2014-11236 (Patent Document 1) includes a power semiconductor element such as an insulated gate bipolar transistor (IGBT), a DCB substrate, a heat dissipation base plate, an insert case, a bus bar, and a lead wire. It discloses a power semiconductor device. The DCB substrate is joined to the heat dissipation base plate. The power semiconductor element is bonded to the DCB substrate. The insert case is joined to the heat dissipation base plate and surrounds the power semiconductor element and the DCB substrate. The insert case is provided with a bus bar. The power semiconductor element is electrically connected to the bus bar via a lead wire. Specifically, one end of the lead wire is joined to the power semiconductor element by using solder. The other end of the lead wire is joined to the bus bar using solder.
特開２０１４－１１２３６号公報Japanese Unexamined Patent Publication No. 2014-11236
　本開示の目的は、パワー半導体装置の信頼性を向上させることである。 The purpose of this disclosure is to improve the reliability of power semiconductor devices.
　本開示のパワー半導体装置は、基板と、第１パワー半導体素子と、引き出し配線と、板状端子とを備える。第１パワー半導体素子は、基板に接合されている第１裏面電極と、第１裏面電極とは反対側の第１おもて面電極とを含む。板状端子は、第１端子部分と、第２端子部分とを含む。第１端子部分は、第１導電接合部材を用いて第１おもて面電極に接合されている。第２端子部分は、第２導電接合部材を用いて引き出し配線に接合されている。第１パワー半導体素子と第１端子部分との間の第１の線膨張係数差は、引き出し配線と第２端子部分との間の第２の線膨張係数差よりも大きい。第１端子部分は、第２端子部分よりも薄い。 The power semiconductor device of the present disclosure includes a substrate, a first power semiconductor element, lead-out wiring, and a plate-shaped terminal. The first power semiconductor element includes a first back surface electrode bonded to the substrate and a first front surface electrode on the opposite side of the first back surface electrode. The plate-shaped terminal includes a first terminal portion and a second terminal portion. The first terminal portion is joined to the first front surface electrode by using the first conductive joining member. The second terminal portion is joined to the lead-out wiring by using the second conductive joining member. The first linear expansion coefficient difference between the first power semiconductor element and the first terminal portion is larger than the second linear expansion coefficient difference between the lead wiring and the second terminal portion. The first terminal portion is thinner than the second terminal portion.
　本開示のパワー半導体装置の製造方法は、第１パワー半導体素子の第１裏面電極を基板に接合することと、板状端子を、第１裏面電極とは反対側の第１パワー半導体素子の第１おもて面電極と引き出し配線とに接合することとを備える。板状端子は、第１端子部分と、第２端子部分とを含む。第１パワー半導体素子と第１端子部分との間の第１の線膨張係数の差は、引き出し配線と第２端子部分との間の第２の線膨張係数の差よりも大きい。第１端子部分は、第２端子部分よりも薄い。第１端子部分が第１導電接合部材を用いて第１おもて面電極に接合されながら、第２端子部分は第２導電接合部材を用いて引き出し配線に接合される。第１端子部分を第１おもて面電極に接合する際、第１導電接合部材は第１熱源を用いて加熱される。第１熱源は、第１温度センサを用いて測定される第１端子部分の第１温度に基づいて制御される。第２端子部分を引き出し配線に接合する際、第２導電接合部材は第２熱源を用いて加熱される。第２熱源は、第２温度センサを用いて測定される第２端子部分の第２温度に基づいて制御される。 The method for manufacturing a power semiconductor device of the present disclosure is to bond the first back electrode of the first power semiconductor element to a substrate, and to attach a plate-shaped terminal to the first power semiconductor element on the side opposite to the first back electrode. 1 It is provided to join the front surface electrode and the lead-out wiring. The plate-shaped terminal includes a first terminal portion and a second terminal portion. The difference in the first linear expansion coefficient between the first power semiconductor element and the first terminal portion is larger than the difference in the second linear expansion coefficient between the lead wiring and the second terminal portion. The first terminal portion is thinner than the second terminal portion. While the first terminal portion is bonded to the first front surface electrode using the first conductive bonding member, the second terminal portion is bonded to the lead-out wiring using the second conductive bonding member. When the first terminal portion is joined to the first front surface electrode, the first conductive joining member is heated by using the first heat source. The first heat source is controlled based on the first temperature of the first terminal portion measured using the first temperature sensor. When the second terminal portion is joined to the lead-out wiring, the second conductive joining member is heated by using the second heat source. The second heat source is controlled based on the second temperature of the second terminal portion measured using the second temperature sensor.
　第１端子部分は、第２端子部分よりも薄いため、第１導電接合部材に印加される熱応力を小さくすることができる。第１導電接合部材にき裂が発生すること、及び、第１端子部分が第１おもて面電極からはく離することが防止される。さらに、第２端子部分は、第１端子部分よりも厚い。第２端子部分は、第１端子部分よりも大きな熱容量を有する。そのため、第２導電接合部材の温度上昇が低減され得る。第２導電接合部材の劣化が低減される。本開示のパワー半導体装置によれば、パワー半導体装置の信頼性が向上され得る。本開示のパワー半導体装置の製造方法によれば、信頼性が向上されたパワー半導体装置を得ることができる。 Since the first terminal portion is thinner than the second terminal portion, the thermal stress applied to the first conductive joining member can be reduced. It is possible to prevent the first conductive joint member from being cracked and the first terminal portion from being separated from the first front surface electrode. Further, the second terminal portion is thicker than the first terminal portion. The second terminal portion has a larger heat capacity than the first terminal portion. Therefore, the temperature rise of the second conductive bonding member can be reduced. Deterioration of the second conductive joint member is reduced. According to the power semiconductor device of the present disclosure, the reliability of the power semiconductor device can be improved. According to the method for manufacturing a power semiconductor device of the present disclosure, a power semiconductor device with improved reliability can be obtained.
実施の形態１に係るパワー半導体装置の概略断面図である。It is the schematic sectional drawing of the power semiconductor device which concerns on Embodiment 1. FIG. 実施の形態１に係るパワー半導体装置の製造方法のフローチャートを示す図である。It is a figure which shows the flowchart of the manufacturing method of the power semiconductor device which concerns on Embodiment 1. FIG. 実施の形態１に係るパワー半導体装置の製造方法の工程Ｓ４のフローチャートを示す図である。It is a figure which shows the flowchart of the process S4 of the manufacturing method of the power semiconductor device which concerns on Embodiment 1. FIG. 実施の形態１に係るパワー半導体装置の製造装置の第一の例を示す概略図である。It is the schematic which shows the 1st example of the manufacturing apparatus of the power semiconductor apparatus which concerns on Embodiment 1. FIG. 実施の形態１に係るパワー半導体装置の製造装置の第一の例及び第二の例のブロック図である。It is a block diagram of the 1st example and the 2nd example of the manufacturing apparatus of the power semiconductor apparatus which concerns on Embodiment 1. FIG. 実施の形態１に係るパワー半導体装置の製造装置の第二の例を示す概略図である。It is the schematic which shows the 2nd example of the manufacturing apparatus of the power semiconductor apparatus which concerns on Embodiment 1. FIG. 実施の形態２に係るパワー半導体装置の概略断面図である。It is the schematic sectional drawing of the power semiconductor device which concerns on Embodiment 2. FIG. 実施の形態３に係るパワー半導体装置の概略断面図である。It is the schematic sectional drawing of the power semiconductor device which concerns on Embodiment 3. FIG.
　以下、本開示の実施の形態を説明する。なお、同一の構成には同一の参照番号を付し、その説明は繰り返さない。 Hereinafter, embodiments of the present disclosure will be described. The same reference number will be assigned to the same configuration, and the description will not be repeated.
　実施の形態１．
　図１を参照して、実施の形態１のパワー半導体装置１を説明する。パワー半導体装置１は、基板１０と、第１パワー半導体素子２０と、引き出し配線４１，４１ｇと、板状端子５０，５０ｇとを主に備える。パワー半導体装置１は、端子台４０とヒートシンク３０とをさらに備えてもよい。パワー半導体装置１は、第２パワー半導体素子２５をさらに備えてもよい。 Embodiment 1.
The power semiconductor device 1 of the first embodiment will be described with reference to FIG. The power semiconductor device 1 mainly includes a substrate 10, a first power semiconductor element 20, lead wiring 41, 41 g, and plate- shaped terminals 50, 50 g. The power semiconductor device 1 may further include a terminal block 40 and a heat sink 30. The power semiconductor device 1 may further include a second power semiconductor element 25.
　基板１０は、絶縁層１１と、おもて面導体層１２と、裏面導体層１３とを含んでいる。基板１０は、第１方向（ｘ方向）と、第１方向に直交する第２方向（ｙ方向）とに沿って延在している。第１方向（ｘ方向）と第２方向（ｙ方向）とに垂直な第３方向（ｚ方向）は、基板１０の厚さ方向である。 The substrate 10 includes an insulating layer 11, a front surface conductor layer 12, and a back surface conductor layer 13. The substrate 10 extends along a first direction (x direction) and a second direction (y direction) orthogonal to the first direction. The third direction (z direction) perpendicular to the first direction (x direction) and the second direction (y direction) is the thickness direction of the substrate 10.
　絶縁層１１は、例えば、窒化アルミニウム（ＡｌＮ）、窒化珪素（Ｓｉ3Ｎ4）、アルミナ（Ａｌ2Ｏ3）のようなセラミック層、または、窒化硼素（ＢＮ）フィラーを含むエポキシ樹脂のような樹脂層である。絶縁層１１は、好ましくは、電気的絶縁性を有し、かつ、高い熱伝導率を有する。絶縁層１１は、例えば、０．３ｍｍ以上１．０ｍｍの厚さを有している。 The insulating layer 11 is, for example, a ceramic layer such as aluminum nitride (AlN), silicon nitride (Si 3 N 4 ), or alumina (Al 2 O 3 ), or an epoxy resin containing a boron nitride (BN) filler. It is a resin layer. The insulating layer 11 preferably has electrical insulation and high thermal conductivity. The insulating layer 11 has a thickness of, for example, 0.3 mm or more and 1.0 mm.
　おもて面導体層１２と裏面導体層１３とは、例えば、銅（Ｃｕ）層、アルミニウム（Ａｌ）層、または、ＣｕとＡｌとの積層体である。おもて面導体層１２と裏面導体層１３とは、各々、例えば、０．２ｍｍ以上の厚さを有している。おもて面導体層１２と裏面導体層１３とは、各々、０．３ｍｍ以上の厚さを有してもよい。おもて面導体層１２と裏面導体層１３とは、各々、例えば、１．０ｍｍ以下の厚さを有している。おもて面導体層１２と裏面導体層１３とは、各々、０．６ｍｍ以下の厚さを有してもよい。おもて面導体層１２と裏面導体層１３が厚いほど、おもて面導体層１２及び裏面導体層１３の放熱性能が高まる。おもて面導体層１２と裏面導体層１３が薄いほど、絶縁層１１とおもて面導体層１２との間の線膨張係数差及び絶縁層１１と裏面導体層１３との間の線膨張係数差に起因しておもて面導体層１２及び裏面導体層１３から絶縁層１１に印加される熱応力が小さくなる。おもて面導体層１２のおもて面は、基板１０の主面１０ａである。 The front surface conductor layer 12 and the back surface conductor layer 13 are, for example, a copper (Cu) layer, an aluminum (Al) layer, or a laminate of Cu and Al. The front surface conductor layer 12 and the back surface conductor layer 13 each have a thickness of, for example, 0.2 mm or more. The front surface conductor layer 12 and the back surface conductor layer 13 may each have a thickness of 0.3 mm or more. The front surface conductor layer 12 and the back surface conductor layer 13 each have a thickness of, for example, 1.0 mm or less. The front surface conductor layer 12 and the back surface conductor layer 13 may each have a thickness of 0.6 mm or less. The thicker the front surface conductor layer 12 and the back surface conductor layer 13, the higher the heat dissipation performance of the front surface conductor layer 12 and the back surface conductor layer 13. The thinner the front surface conductor layer 12 and the back surface conductor layer 13, the difference in the coefficient of linear expansion between the insulating layer 11 and the front surface conductor layer 12 and the linear expansion coefficient between the insulating layer 11 and the back surface conductor layer 13. Due to the difference, the thermal stress applied to the insulating layer 11 from the front conductor layer 12 and the back surface conductor layer 13 becomes small. Front surface The front surface of the conductor layer 12 is the main surface 10a of the substrate 10.
　第１パワー半導体素子２０と第２パワー半導体素子２５とは、第１方向（ｘ方向）において互いに隣り合って配置されている。本実施の形態では、第１パワー半導体素子２０及び第２パワー半導体素子２５は、珪素（Ｓｉ）で形成されている。第１パワー半導体素子２０及び第２パワー半導体素子２５は、炭化ケイ素（ＳｉＣ）、窒化ガリウム（ＧａＮ）、ダイヤモンドのような、Ｓｉよりも大きなバンドギャップを有する半導体材料で形成されてもよい。Ｓｉよりも大きなバンドギャップを有する半導体材料は、第１パワー半導体素子２０及び第２パワー半導体素子２５が高温でも正常に動作することを可能にするとともに、パワー半導体装置１の小型化を可能にする。 The first power semiconductor element 20 and the second power semiconductor element 25 are arranged adjacent to each other in the first direction (x direction). In the present embodiment, the first power semiconductor element 20 and the second power semiconductor element 25 are made of silicon (Si). The first power semiconductor element 20 and the second power semiconductor element 25 may be formed of a semiconductor material having a band gap larger than that of Si, such as silicon carbide (SiC), gallium nitride (GaN), and diamond. A semiconductor material having a band gap larger than that of Si enables the first power semiconductor element 20 and the second power semiconductor element 25 to operate normally even at a high temperature, and also enables the power semiconductor device 1 to be miniaturized. ..
　第１パワー半導体素子２０は、第１裏面電極２２と、第１裏面電極２２とは反対側の第１おもて面電極２１とを含む。第１裏面電極２２と第１おもて面電極２１とは、第１パワー半導体素子２０の厚さ方向（第３方向（ｚ方向））において互いに離間している。第２パワー半導体素子２５は、第２裏面電極２７と、第２裏面電極２７とは反対側の第２おもて面電極２６とを含む。第２裏面電極２７と第２おもて面電極２６とは、第２パワー半導体素子２５の厚さ方向（第３方向（ｚ方向））において互いに離間している。第１パワー半導体素子２０の厚さ方向（第３方向（ｚ方向））及び第２パワー半導体素子２５の厚さ方向（第３方向（ｚ方向））は、基板１０の主面１０ａの法線方向（第３方向（ｚ方向））に平行である。 The first power semiconductor element 20 includes a first back surface electrode 22 and a first front surface electrode 21 on the opposite side of the first back surface electrode 22. The first back surface electrode 22 and the first front surface electrode 21 are separated from each other in the thickness direction (third direction (z direction)) of the first power semiconductor element 20. The second power semiconductor element 25 includes a second back surface electrode 27 and a second front surface electrode 26 on the opposite side of the second back surface electrode 27. The second back surface electrode 27 and the second front surface electrode 26 are separated from each other in the thickness direction (third direction (z direction)) of the second power semiconductor element 25. The thickness direction of the first power semiconductor element 20 (third direction (z direction)) and the thickness direction of the second power semiconductor element 25 (third direction (z direction)) are normals of the main surface 10a of the substrate 10. It is parallel to the direction (third direction (z direction)).
　本実施の形態では、第１パワー半導体素子２０は、絶縁ゲートバイポーラトランジスタ（ＩＧＢＴ）であり、第２パワー半導体素子２５は、フリーホイールダイオード（ＦＷＤ）である。第１おもて面電極２１は、エミッタ電極（図示せず）と、ゲート電極（図示せず）とを含み、第１裏面電極２２はコレクタ電極である。第２おもて面電極２６は、アノード電極である。第２裏面電極２７は、カソード電極である。第１パワー半導体素子２０及び第２パワー半導体素子２５は、金属酸化物半導体電界効果トランジスタ（ＭＯＳＦＥＴ）のような他のパワー半導体素子であってもよい。 In the present embodiment, the first power semiconductor element 20 is an insulated gate bipolar transistor (IGBT), and the second power semiconductor element 25 is a freewheel diode (FWD). The first front surface electrode 21 includes an emitter electrode (not shown) and a gate electrode (not shown), and the first back surface electrode 22 is a collector electrode. The second front surface electrode 26 is an anode electrode. The second back surface electrode 27 is a cathode electrode. The first power semiconductor element 20 and the second power semiconductor element 25 may be other power semiconductor elements such as a metal oxide semiconductor field effect transistor (MOSFET).
　第１パワー半導体素子２０の第１裏面電極２２は、導電接合部材２３を用いて、基板１０のおもて面導体層１２に接合されている。第２パワー半導体素子２５の第２裏面電極２７は、導電接合部材２８を用いて、基板１０のおもて面導体層１２に接合されている。導電接合部材２３及び導電接合部材２８は、例えば、鉛フリーはんだのようなはんだ、銀（Ａｇ）、銅（Ｃｕ）、または、銅スズ（ＣｕＳｎ）合金で形成されている。導電接合部材２３及び導電接合部材２８は、例えば、２５０℃以上の融点を有している。導電接合部材２３及び導電接合部材２８は、３００℃以上の融点を有してもよい。 The first back electrode 22 of the first power semiconductor element 20 is bonded to the front surface conductor layer 12 of the substrate 10 by using the conductive bonding member 23. The second back electrode 27 of the second power semiconductor element 25 is bonded to the front surface conductor layer 12 of the substrate 10 by using the conductive bonding member 28. The conductive bonding member 23 and the conductive bonding member 28 are formed of, for example, a solder such as lead-free solder, silver (Ag), copper (Cu), or a copper tin (CuSn) alloy. The conductive joining member 23 and the conductive joining member 28 have, for example, a melting point of 250 ° C. or higher. The conductive joining member 23 and the conductive joining member 28 may have a melting point of 300 ° C. or higher.
　導電接合部材２３及び導電接合部材２８は、銀微粒子焼結体、銅微粒子焼結体もしくはＣｕＳｎ微粒子焼結体のような金属微粒子焼結体で形成されてもよい。本明細書では、微粒子は、１００μｍ以下の直径を有する粒子を意味する。微粒子は、１０μｍ以下の直径を有する粒子であってもよく、ナノ粒子であってもよい。金属微粒子焼結体は、金属微粒子が微粒子を構成する金属の融点よりも低い温度で焼結する現象を利用して、金属微粒子が分散されたペーストを焼結することによって得られる。こうして得られた金属微粒子焼結体は、微粒子を構成する金属の融点を有しており、はんだに比べて高い融点を有している。金属微粒子焼結体は、第１パワー半導体素子２０及び第２パワー半導体素子２５が高温でも正常に動作することを可能にする。金属微粒子焼結体は、パワー半導体装置１の信頼性を向上させるとともに、パワー半導体装置１の小型化を可能にする。 The conductive bonding member 23 and the conductive bonding member 28 may be formed of a metal fine particle sintered body such as a silver fine particle sintered body, a copper fine particle sintered body, or a CuSn fine particle sintered body. As used herein, the fine particles mean particles having a diameter of 100 μm or less. The fine particles may be particles having a diameter of 10 μm or less, or may be nanoparticles. The metal fine particle sintered body is obtained by sintering a paste in which metal fine particles are dispersed by utilizing the phenomenon that the metal fine particles are sintered at a temperature lower than the melting point of the metal constituting the fine particles. The metal fine particle sintered body thus obtained has a melting point of the metal constituting the fine particles, and has a higher melting point than that of solder. The metal fine particle sintered body enables the first power semiconductor element 20 and the second power semiconductor element 25 to operate normally even at a high temperature. The metal fine particle sintered body improves the reliability of the power semiconductor device 1 and enables the power semiconductor device 1 to be miniaturized.
　第１おもて面電極２１上に、第１導電接合部材５５との拡散接合に適した第１メタライズ層（図示せず）が設けられていてもよい。第２おもて面電極２６上に、第３導電接合部材５６との拡散接合に適した第２メタライズ層（図示せず）が設けられていてもよい。第１導電接合部材５５及び第３導電接合部材５６がはんだである場合、第１メタライズ層及び第２メタライズ層は、各々、例えば、最表面側から金（Ａｕ）層とニッケル（Ｎｉ）層とが積層された積層体である。Ａｕ層は、第１おもて面電極２１及び第２おもて面電極２６の最表面の酸化を防止するとともに、はんだに対する濡れ性を向上させる。Ｎｉ層は、第１おもて面電極２１及び第２おもて面電極２６へのはんだの拡散を防止する。Ｎｉ層の厚さは、はんだ接合時の熱印加の態様と第１パワー半導体素子２０及び第２パワー半導体素子２５の動作時の最高温度とを考慮して決定される。Ｎｉ層は、例えば、１．５μｍ以上５．０μｍ以下の厚さを有している。Ｎｉ層は、例えば、スパッタリングまたはめっきによって形成される。 A first metallized layer (not shown) suitable for diffusion bonding with the first conductive bonding member 55 may be provided on the first front surface electrode 21. A second metallized layer (not shown) suitable for diffusion bonding with the third conductive bonding member 56 may be provided on the second front surface electrode 26. When the first conductive bonding member 55 and the third conductive bonding member 56 are solders, the first metallized layer and the second metallized layer are, for example, a gold (Au) layer and a nickel (Ni) layer from the outermost surface side, respectively. Is a laminated body in which is laminated. The Au layer prevents oxidation of the outermost surfaces of the first front surface electrode 21 and the second front surface electrode 26, and improves the wettability with respect to the solder. The Ni layer prevents the solder from diffusing into the first front surface electrode 21 and the second front surface electrode 26. The thickness of the Ni layer is determined in consideration of the mode of heat application during solder bonding and the maximum temperature during operation of the first power semiconductor element 20 and the second power semiconductor element 25. The Ni layer has, for example, a thickness of 1.5 μm or more and 5.0 μm or less. The Ni layer is formed, for example, by sputtering or plating.
　引き出し配線４１と板状端子５０とは、第１パワー半導体素子２０及び第２パワー半導体素子２５を、パワー半導体装置１の外部にある部材と電気的に接続する。電流または電圧が、引き出し配線４１及び板状端子５０を通って、パワー半導体装置１の外部にある部材から第１パワー半導体素子２０及び第２パワー半導体素子２５に供給される、または、第１パワー半導体素子２０及び第２パワー半導体素子２５からパワー半導体装置１の外部にある部材に供給される。パワー半導体装置１の外部にある部材は、例えば、モータであり、パワー半導体装置１は、例えば、モータを駆動するインバータである。モータを駆動する場合、数百アンペアの電流が、引き出し配線４１及び板状端子５０に流れる。 The lead-out wiring 41 and the plate-shaped terminal 50 electrically connect the first power semiconductor element 20 and the second power semiconductor element 25 to a member outside the power semiconductor device 1. A current or voltage is supplied to the first power semiconductor element 20 and the second power semiconductor element 25 from a member outside the power semiconductor device 1 through the lead-out wiring 41 and the plate-shaped terminal 50, or the first power. It is supplied from the semiconductor element 20 and the second power semiconductor element 25 to a member outside the power semiconductor device 1. The member outside the power semiconductor device 1 is, for example, a motor, and the power semiconductor device 1 is, for example, an inverter for driving a motor. When driving a motor, a current of several hundred amperes flows through the lead-out wiring 41 and the plate-shaped terminal 50.
　引き出し配線４１及び板状端子５０は、各々、銅（Ｃｕ）、銅タングステン（ＣｕＷ）合金、または、Ｃｕ層／インバー（Ｆｅ－３６％Ｎｉ合金）層／Ｃｕ層で構成される積層体で形成されている。本実施の形態では、引き出し配線４１及び板状端子５０とは、同じ材料で形成されている。引き出し配線４１及び板状端子５０とは、互いに異なる材料で形成されてもよい。 The lead-out wiring 41 and the plate-shaped terminal 50 are formed of a laminate composed of a copper (Cu), copper tungsten (CuW) alloy, or a Cu layer / Invar (Fe-36% Ni alloy) layer / Cu layer, respectively. Has been done. In the present embodiment, the lead-out wiring 41 and the plate-shaped terminal 50 are made of the same material. The lead-out wiring 41 and the plate-shaped terminal 50 may be made of different materials from each other.
　引き出し配線４１は、主に、第２方向（ｙ方向）に延在しており、引き出し配線４１の長手方向は第２方向（ｙ方向）である。板状端子５０は、主に、引き出し配線４１と交差する第１方向（ｘ方向）に延在しており、板状端子５０の長手方向は第１方向（ｘ方向）である。 The lead-out wiring 41 mainly extends in the second direction (y direction), and the longitudinal direction of the lead-out wiring 41 is the second direction (y direction). The plate-shaped terminal 50 mainly extends in the first direction (x direction) intersecting the lead-out wiring 41, and the longitudinal direction of the plate-shaped terminal 50 is the first direction (x direction).
　板状端子５０は、第１端子部分５１と、第２端子部分５２とを含む。板状端子５０は、第１端子部分５１と第２端子部分５２とを接続する第３端子部分５３をさらに含んでもよい。本実施の形態では、第１端子部分５１と第２端子部分５２と第３端子部分５３とは、同じ材料で形成されていて、板状端子５０は単一部品で構成されている。単一部品で構成されている板状端子５０は、第１端子部分５１と第２端子部分５２と第３端子部分５３とが互いに別部品であり、かつ、第１端子部分５１及び第２端子部分５２が例えばはんだまたは溶接によって互いに接続されるとともに、第２端子部分５２及び第３端子部分５３が例えばはんだまたは溶接によって互いに接続されることによって形成される板状端子５０に比べて、より高い信頼性を有する。 The plate-shaped terminal 50 includes a first terminal portion 51 and a second terminal portion 52. The plate-shaped terminal 50 may further include a third terminal portion 53 that connects the first terminal portion 51 and the second terminal portion 52. In the present embodiment, the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are made of the same material, and the plate-shaped terminal 50 is composed of a single component. In the plate-shaped terminal 50 composed of a single component, the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are separate parts from each other, and the first terminal portion 51 and the second terminal Higher than the plate-shaped terminals 50 formed by connecting the portions 52 to each other, for example by soldering or welding, and connecting the second terminal portion 52 and the third terminal portion 53 to each other, for example by soldering or welding. Has reliability.
　板状端子５０は、複数の部品で構成されてもよい。例えば、第１端子部分５１と第２端子部分５２と第３端子部分５３とは互いに別部品であり、かつ、第１端子部分５１及び第２端子部分５２が例えばはんだまたは溶接によって互いに接続されるとともに、第２端子部分５２及び第３端子部分５３が例えばはんだまたは溶接によって互いに接続されてもよい。そのため、板状端子５０が、基板１０の厚さ方向（第３方向（ｚ方向））からの平面視において、クランク形状のような複雑な形状を有していても、板状端子５０は、相対的に高い歩留まりでかつ相対的に低コストで形成され得る。第１端子部分５１と第２端子部分５２と第３端子部分５３とが互いに別部品である場合には、第１端子部分５１と第２端子部分５２と第３端子部分５３とは、同じ材料で形成されてもよいし、互いに異なる材料で形成されてもよい。 The plate-shaped terminal 50 may be composed of a plurality of parts. For example, the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are separate parts from each other, and the first terminal portion 51 and the second terminal portion 52 are connected to each other by, for example, soldering or welding. At the same time, the second terminal portion 52 and the third terminal portion 53 may be connected to each other by, for example, soldering or welding. Therefore, even if the plate-shaped terminal 50 has a complicated shape such as a crank shape in a plan view from the thickness direction (third direction (z direction)) of the substrate 10, the plate-shaped terminal 50 can be used. It can be formed with a relatively high yield and a relatively low cost. When the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are separate parts, the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 are made of the same material. It may be formed of materials different from each other.
　第１端子部分５１は、第１方向（ｘ方向）に延在しており、第１端子部分５１の長手方向は第１方向（ｘ方向）である。第１端子部分５１は、基板１０の主面１０ａに沿って延在している。第２端子部分５２は、第１方向（ｘ方向）に延在しており、第２端子部分５２の長手方向は第１方向（ｘ方向）である。第２端子部分５２は、基板１０の主面１０ａに沿って延在している。第３端子部分５３は、第３方向（ｚ方向）に延在しており、第３端子部分５３の長手方向は第３方向（ｚ方向）である。第３端子部分５３は、第１パワー半導体素子２０の厚さ方向（第３方向（ｚ方向））に沿って延在している。第１パワー半導体素子２０の厚さ方向（第３方向（ｚ方向））における第１端子部分５１と基板１０の主面１０ａとの間の距離は、第１パワー半導体素子２０の厚さ方向（第３方向（ｚ方向））における第２端子部分５２と基板１０の主面１０ａとの間の距離よりも短い。 The first terminal portion 51 extends in the first direction (x direction), and the longitudinal direction of the first terminal portion 51 is the first direction (x direction). The first terminal portion 51 extends along the main surface 10a of the substrate 10. The second terminal portion 52 extends in the first direction (x direction), and the longitudinal direction of the second terminal portion 52 is the first direction (x direction). The second terminal portion 52 extends along the main surface 10a of the substrate 10. The third terminal portion 53 extends in the third direction (z direction), and the longitudinal direction of the third terminal portion 53 is the third direction (z direction). The third terminal portion 53 extends along the thickness direction (third direction (z direction)) of the first power semiconductor element 20. The distance between the first terminal portion 51 and the main surface 10a of the substrate 10 in the thickness direction of the first power semiconductor element 20 (third direction (z direction)) is the thickness direction of the first power semiconductor element 20 (the third direction (z direction)). It is shorter than the distance between the second terminal portion 52 and the main surface 10a of the substrate 10 in the third direction (z direction).
　第１端子部分５１は、第２端子部分５２よりも薄い。特定的には、第２端子部分５２の第２厚さｔ2に対する第１端子部分５１の第１厚さｔ1の比は、０．７５以下である。この比は、０．６０以下であってもよい。第２端子部分５２の第２厚さｔ2に対する第１端子部分５１の第１厚さｔ1の比０．１０以上である。この比は、０．２０以上であってもよい。第３端子部分５３は、第２端子部分５２よりも薄い。特定的には、第２端子部分５２の第２厚さｔ2に対する第３端子部分５３の第３厚さｔ3の比は、０．７５以下である。この比は、０．６０以下であってもよい。第２端子部分５２の第２厚さｔ2に対する第３端子部分５３の第３厚さｔ3の比０．１０以上である。この比は、０．２０以上であってもよい。 The first terminal portion 51 is thinner than the second terminal portion 52. Specifically, the ratio of the first thickness t 1 of the first terminal portion 51 to the second thickness t 2 of the second terminal portion 52 is 0.75 or less. This ratio may be 0.60 or less. The ratio of the first thickness t 1 of the first terminal portion 51 to the second thickness t 2 of the second terminal portion 52 is 0.10 or more. This ratio may be 0.20 or more. The third terminal portion 53 is thinner than the second terminal portion 52. Specifically, the ratio of the third thickness t 3 of the third terminal portion 53 to the second thickness t 2 of the second terminal portion 52 is 0.75 or less. This ratio may be 0.60 or less. The ratio of the third thickness t 3 of the third terminal portion 53 to the second thickness t 2 of the second terminal portion 52 is 0.10 or more. This ratio may be 0.20 or more.
　第１端子部分５１の第１厚さｔ1は、０．６０ｍｍ以下である。第１厚さｔ1は、０．５０ｍｍ以下であってもよい。第１端子部分５１の第１厚さｔ1は、例えば、０．１５ｍｍ以上である。第１厚さｔ1は、０．２０ｍｍ以上であってもよい。第２端子部分５２の第２厚さｔ2は、例えば、０．８０ｍｍ以上である。第２厚さｔ2は、１．０ｍｍ以上であってもよい。第２端子部分５２の第２厚さｔ2は、例えば、１．５０ｍｍ以下である。第２端子部分５２の第２厚さｔ2は、１．３５ｍｍ以下であってもよい。第３端子部分５３の第３厚さｔ3は、例えば、０．６０ｍｍ以下である。第３厚さｔ3は、０．５０ｍｍ以下であってもよい。第３端子部分５３の第３厚さｔ3は、例えば、０．１５ｍｍ以上である。第３厚さｔ3は、０．２０ｍｍ以上であってもよい。第３端子部分５３の第３厚さｔ3は、第１端子部分５１の第１厚さｔ1に等しくてもよい。 The first thickness t 1 of the first terminal portion 51 is 0.60 mm or less. The first thickness t 1 may be 0.50 mm or less. The first thickness t 1 of the first terminal portion 51 is, for example, 0.15 mm or more. The first thickness t 1 may be 0.20 mm or more. The second thickness t 2 of the second terminal portion 52 is, for example, 0.80 mm or more. The second thickness t 2 may be 1.0 mm or more. The second thickness t 2 of the second terminal portion 52 is, for example, 1.50 mm or less. The second thickness t 2 of the second terminal portion 52 may be 1.35 mm or less. The third thickness t 3 of the third terminal portion 53 is, for example, 0.60 mm or less. The third thickness t 3 may be 0.50 mm or less. The third thickness t 3 of the third terminal portion 53 is, for example, 0.15 mm or more. The third thickness t 3 may be 0.20 mm or more. The third thickness t 3 of the third terminal portion 53 may be equal to the first thickness t 1 of the first terminal portion 51.
　第１パワー半導体素子２０と第１端子部分５１との間の第１の線膨張係数差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数差よりも大きい。第２パワー半導体素子２５と第１端子部分５１との間の第３の線膨張係数差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数差よりも大きい。 The first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52. The third linear expansion coefficient difference between the second power semiconductor element 25 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52.
　互いに隣り合って配置されている第１パワー半導体素子２０と第２パワー半導体素子２５とは、ともに、一つの板状端子５０に接合されている。そのため、配線インダクタンスを小さくすることができて、第１パワー半導体素子２０及び第２パワー半導体素子２５に印加されるサージ電圧を小さくすることができる。また、板状端子５０と第１パワー半導体素子２０との接合と、板状端子５０と第２パワー半導体素子２５との接合とを、一回の工程で行うことができる。パワー半導体装置１の生産性が向上する。 Both the first power semiconductor element 20 and the second power semiconductor element 25 arranged adjacent to each other are joined to one plate-shaped terminal 50. Therefore, the wiring inductance can be reduced, and the surge voltage applied to the first power semiconductor element 20 and the second power semiconductor element 25 can be reduced. Further, the joining of the plate-shaped terminal 50 and the first power semiconductor element 20 and the joining of the plate-shaped terminal 50 and the second power semiconductor element 25 can be performed in one step. The productivity of the power semiconductor device 1 is improved.
　具体的には、第１端子部分５１は、第１導電接合部材５５を用いて第１おもて面電極２１に接合されている。第２端子部分５２は、第２導電接合部材５７を用いて引き出し配線４１に接合されている。第１端子部分５１は、第３導電接合部材５６を用いて第２おもて面電極２６に接合されている。 Specifically, the first terminal portion 51 is joined to the first front surface electrode 21 by using the first conductive joining member 55. The second terminal portion 52 is joined to the lead-out wiring 41 by using the second conductive joining member 57. The first terminal portion 51 is bonded to the second front surface electrode 26 by using the third conductive bonding member 56.
　第２導電接合部材５７は、第１導電接合部材５５及び第３導電接合部材５６と同一材料で形成されてもよいし、第１導電接合部材５５及び第３導電接合部材５６とは異なる材料で形成されてもよい。第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は、例えば、鉛フリーはんだのようなはんだ、銀（Ａｇ）、銅（Ｃｕ）または銅スズ（ＣｕＳｎ）合金で形成されている。第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は、２５０℃以上の融点を有している。第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は、３００℃以上の融点を有してもよい。 The second conductive joining member 57 may be formed of the same material as the first conductive joining member 55 and the third conductive joining member 56, or may be made of a different material from the first conductive joining member 55 and the third conductive joining member 56. It may be formed. The first conductive bonding member 55, the second conductive bonding member 57, and the third conductive bonding member 56 are formed of, for example, a solder such as lead-free solder, silver (Ag), copper (Cu), or a copper tin (CuSn) alloy. Has been done. The first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 have a melting point of 250 ° C. or higher. The first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 may have a melting point of 300 ° C. or higher.
　特定的には、第１導電接合部材５５は、Ｓｎを主成分として含む第１はんだである。第１はんだは、Ｓｎよりも高い０．２％耐力を有している。第１はんだは、例えば、Ｓｎ－Ｃｕ系はんだ、または、Ｓｎ－Ｓｂ系はんだである。第２導電接合部材５７は、Ｓｎを主成分として含む第２はんだである。第２はんだは、Ｓｎよりも高い熱伝導率を有している。第２はんだは、例えば、Ｓｎ－Ａｕ系はんだ、または、Ｓｎ－Ａｇ系はんだである。第３導電接合部材５６は、Ｓｎを主成分として含む第３はんだで形成されている。第３はんだは、Ｓｎよりも高い０．２％耐力を有している。第３はんだは、例えば、Ｓｎ－Ｃｕ系はんだ、または、Ｓｎ－Ｓｂ系はんだである。第１導電接合部材５５及び第３導電接合部材５６は、第２導電接合部材５７よりも高い０．２％耐力を有している。第２導電接合部材５７は、第１導電接合部材５５及び第３導電接合部材５６よりも、高い熱伝導率を有している。 Specifically, the first conductive bonding member 55 is a first solder containing Sn as a main component. The first solder has a 0.2% proof stress higher than that of Sn. The first solder is, for example, Sn—Cu-based solder or Sn—Sb-based solder. The second conductive bonding member 57 is a second solder containing Sn as a main component. The second solder has a higher thermal conductivity than Sn. The second solder is, for example, Sn-Au-based solder or Sn-Ag-based solder. The third conductive bonding member 56 is formed of a third solder containing Sn as a main component. The third solder has a 0.2% proof stress higher than that of Sn. The third solder is, for example, Sn—Cu-based solder or Sn—Sb-based solder. The first conductive joining member 55 and the third conductive joining member 56 have a higher 0.2% proof stress than the second conductive joining member 57. The second conductive joint member 57 has a higher thermal conductivity than the first conductive joint member 55 and the third conductive joint member 56.
　第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は、銀微粒子焼結体、銅微粒子焼結体もしくはＣｕＳｎ微粒子焼結体のような金属微粒子焼結体で形成されてもよい。金属微粒子焼結体は、金属微粒子が微粒子を構成する金属の融点よりも低い温度で焼結する現象を利用して、金属微粒子が分散されたペーストを焼結することによって得られる。こうして得られた金属微粒子焼結体は、微粒子を構成する金属の融点を有しており、はんだに比べて高い融点を有している。金属微粒子焼結体は、第１パワー半導体素子２０及び第２パワー半導体素子２５が高温でも正常に動作することを可能にする。金属微粒子焼結体は、パワー半導体装置１の信頼性を向上させるとともに、パワー半導体装置１の小型化を可能にする。 The first conductive bonding member 55, the second conductive bonding member 57, and the third conductive bonding member 56 are formed of a metal fine particle sintered body such as a silver fine particle sintered body, a copper fine particle sintered body, or a CuSn fine particle sintered body. You may. The metal fine particle sintered body is obtained by sintering a paste in which metal fine particles are dispersed by utilizing the phenomenon that the metal fine particles are sintered at a temperature lower than the melting point of the metal constituting the fine particles. The metal fine particle sintered body thus obtained has a melting point of the metal constituting the fine particles, and has a higher melting point than that of solder. The metal fine particle sintered body enables the first power semiconductor element 20 and the second power semiconductor element 25 to operate normally even at a high temperature. The metal fine particle sintered body improves the reliability of the power semiconductor device 1 and enables the power semiconductor device 1 to be miniaturized.
　端子台４０は、例えば、ポリフェニレンサルファイド（ＰＰＳ）または液晶ポリマー（ＬＣＰ）のような、耐熱性を有する絶縁樹脂で形成されている。端子台４０の熱伝導率は、引き出し配線４１の熱伝導率よりも小さく、かつ、板状端子５０の熱伝導率よりも小さい。端子台４０の熱伝導率は、第１パワー半導体素子２０の熱伝導率より小さく、かつ、第２パワー半導体素子２５の熱伝導率より小さい。端子台４０の熱伝導率は、例えば、１．０Ｗ／ｍＫ以下である。引き出し配線４１の一部は、端子台４０に埋め込まれている。引き出し配線４１の残部は、端子台４０から露出している。板状端子５０の第２端子部分５２は、第２導電接合部材５７を用いて、端子台４０から露出した引き出し配線４１の部分に接合されている。 The terminal block 40 is made of a heat-resistant insulating resin such as polyphenylene sulfide (PPS) or liquid crystal polymer (LCP). The thermal conductivity of the terminal block 40 is smaller than the thermal conductivity of the lead-out wiring 41 and smaller than the thermal conductivity of the plate-shaped terminal 50. The thermal conductivity of the terminal block 40 is smaller than the thermal conductivity of the first power semiconductor element 20 and smaller than the thermal conductivity of the second power semiconductor element 25. The thermal conductivity of the terminal block 40 is, for example, 1.0 W / mK or less. A part of the lead-out wiring 41 is embedded in the terminal block 40. The rest of the lead-out wiring 41 is exposed from the terminal block 40. The second terminal portion 52 of the plate-shaped terminal 50 is joined to the portion of the lead-out wiring 41 exposed from the terminal block 40 by using the second conductive joining member 57.
　引き出し配線４１ｇは、引き出し配線４１と同様に構成されている。引き出し配線４１ｇは、第２方向（ｙ方向）に延在しており、引き出し配線４１ｇの長手方向は、第２方向（ｙ方向）である。引き出し配線４１ｇの一部は、端子台４０に埋め込まれている。引き出し配線４１ｇの残部は、端子台４０から露出している。引き出し配線４１ｇは、端子台４０を構成する絶縁樹脂によって、引き出し配線４１から電気的に絶縁されている。 The lead-out wiring 41g is configured in the same manner as the lead-out wiring 41. The lead-out wiring 41g extends in the second direction (y direction), and the longitudinal direction of the lead-out wiring 41g is the second direction (y direction). A part of the lead-out wiring 41 g is embedded in the terminal block 40. The rest of the lead-out wiring 41 g is exposed from the terminal block 40. The lead-out wiring 41g is electrically insulated from the lead-out wiring 41 by the insulating resin constituting the terminal block 40.
　板状端子５０ｇは、板状端子５０と同様に構成されている。板状端子５０ｇは、主に、引き出し配線４１ｇと交差する第１方向（ｘ方向）に延在しており、板状端子５０ｇの長手方向は、第１方向（ｘ方向）である。板状端子５０ｇの一端は、導電接合部材（図示せず）を介して、端子台４０から露出している引き出し配線４１ｇの部分に接続されている。板状端子５０ｇの他端は、導電接合部材（図示せず）を介して、基板１０のおもて面導体層１２に接続されている。 The plate-shaped terminal 50g is configured in the same manner as the plate-shaped terminal 50. The plate-shaped terminal 50g extends mainly in the first direction (x direction) intersecting the lead-out wiring 41g, and the longitudinal direction of the plate-shaped terminal 50g is the first direction (x direction). One end of the plate-shaped terminal 50g is connected to a portion of the lead-out wiring 41g exposed from the terminal block 40 via a conductive joining member (not shown). The other end of the plate-shaped terminal 50g is connected to the front surface conductor layer 12 of the substrate 10 via a conductive bonding member (not shown).
　ヒートシンク３０は、第１パワー半導体素子２０及び第２パワー半導体素子２５で発生した熱を、パワー半導体装置１の外部へ放散する。ヒートシンク３０は、例えば、銅（Ｃｕ）またはアルミニウム（Ａｌ）のような高い熱伝導率を有する材料で形成されている。パワー半導体装置１を自動車に適用する場合、自動車の軽量化及び燃費向上のために、ヒートシンク３０は、好ましくは、Ａｌで形成されている。 The heat sink 30 dissipates the heat generated by the first power semiconductor element 20 and the second power semiconductor element 25 to the outside of the power semiconductor device 1. The heat sink 30 is made of a material having a high thermal conductivity, for example, copper (Cu) or aluminum (Al). When the power semiconductor device 1 is applied to an automobile, the heat sink 30 is preferably made of Al in order to reduce the weight of the automobile and improve fuel efficiency.
　ヒートシンク３０は、天板３１と、複数の放熱フィン３２と、ジャケット３３とを含んでいる。天板３１とジャケット３３との間には、冷媒３７の流路３６が形成されている。複数の放熱フィン３２は、流路３６の一部を規定する天板３１の裏面に取り付けられており、流路３６内に配置されている。天板３１及びジャケット３３には、流路３６の入口３４と出口３５とが設けられている。冷媒３７は、例えば、水である。冷媒３７は、ラジエータ（図示せず）から流路３６の入口３４に流れる。冷媒３７は、流路３６を流れて、流路３６の出口３５からラジエータに流れる。冷媒３７は、ラジエータ及びヒートシンク３０を循環している。 The heat sink 30 includes a top plate 31, a plurality of heat radiation fins 32, and a jacket 33. A flow path 36 for the refrigerant 37 is formed between the top plate 31 and the jacket 33. The plurality of heat radiation fins 32 are attached to the back surface of the top plate 31 that defines a part of the flow path 36, and are arranged in the flow path 36. The top plate 31 and the jacket 33 are provided with an inlet 34 and an outlet 35 of the flow path 36. The refrigerant 37 is, for example, water. The refrigerant 37 flows from the radiator (not shown) to the inlet 34 of the flow path 36. The refrigerant 37 flows through the flow path 36 and flows from the outlet 35 of the flow path 36 to the radiator. The refrigerant 37 circulates in the radiator and the heat sink 30.
　冷媒３７がヒートシンク３０から漏れ出すことを防ぐために、天板３１は、ジャケット３３に、液密に取り付けられている。第一の例では、天板３１とジャケット３３との間にゴム製のＯリングを介在させて、天板３１とジャケット３３とを互いにねじで固定してもよい。第二の例では、天板３１とジャケット３３との間にシール材を塗布して、天板３１とジャケット３３とを互いにねじで固定してもよい。第三の例では、天板３１とジャケット３３とを互いにロウ付けしてもよい。第四の例では、天板３１とジャケット３３とを互いに摩擦撹拌接合してもよい。 The top plate 31 is liquid-tightly attached to the jacket 33 in order to prevent the refrigerant 37 from leaking from the heat sink 30. In the first example, a rubber O-ring may be interposed between the top plate 31 and the jacket 33, and the top plate 31 and the jacket 33 may be fixed to each other with screws. In the second example, a sealing material may be applied between the top plate 31 and the jacket 33, and the top plate 31 and the jacket 33 may be fixed to each other with screws. In the third example, the top plate 31 and the jacket 33 may be brazed to each other. In the fourth example, the top plate 31 and the jacket 33 may be friction stir welded to each other.
　基板１０は、ヒートシンク３０に取り付けられている。具体的には、基板１０の裏面導体層１３は、接合部材１４を用いて、ヒートシンク３０の天板３１に取り付けられている。接合部材１４は、例えば、アルミニウム珪素（ＡｌＳｉ）ロウ材、または、Ｓｎを主成分として含むはんだである。接合部材１４としてＳｎ系はんだを用い、かつ、ヒートシンク３０がＡｌで形成されている場合には、Ｓｎ系はんだと合金を形成し得るめっき層（例えば、Ｎｉめっき層またはＳｎめっき層）をヒートシンク３０に予め施してもよい。このめっき層は、Ｓｎ系はんだと合金化しやすいため、Ｓｎ系はんだとＡｌ製のヒートシンク３０とを接合し容易にする。このめっき層は、例えば、２μｍ以上１０μｍ以下の厚さを有しており、良好なはんだ濡れ性と高い接合信頼性とを実現する。 The board 10 is attached to the heat sink 30. Specifically, the back surface conductor layer 13 of the substrate 10 is attached to the top plate 31 of the heat sink 30 by using the joining member 14. The joining member 14 is, for example, an aluminum silicon (AlSi) brazing material or a solder containing Sn as a main component. When Sn-based solder is used as the joining member 14 and the heat sink 30 is formed of Al, the heat-resistant 30 is a plating layer (for example, Ni plating layer or Sn plating layer) capable of forming an alloy with Sn-based solder. May be applied in advance. Since this plating layer is easily alloyed with Sn-based solder, it is easy to join the Sn-based solder and the heat sink 30 made of Al. This plating layer has, for example, a thickness of 2 μm or more and 10 μm or less, and realizes good solder wettability and high bonding reliability.
　例えば、ヒートシンク３０がＡｌ製である場合、ヒートシンク３０の線膨張係数は、Ａｌの線膨張係数（２３ｐｐｍ／Ｋ）で与えられる。基板１０が、０．３２ｍｍの厚さを有するＳｉ3Ｎ4で形成されている絶縁層１１と、０．５０ｍｍの厚さを有するＣｕ板で形成されているおもて面導体層１２と、０．５０ｍｍの厚さを有するＣｕ板で形成されている裏面導体層１３とで構成されている場合、基板１０の線膨張係数は約７ｐｐｍ／Ｋ以上約８ｐｐｍ／Ｋ以下となる。そのため、基板１０とヒートシンク３０との間の線膨張係数差が大きくなる。基板１０とヒートシンク３０との間の線膨張係数差が大きい場合には、接合部材１４として、０．２％耐力が大きい接合部材を用いることが好ましい。０．２％耐力が大きい接合部材は、接合部材１４のき裂進展速度（負荷１サイクルあたりのき裂進展量）を小さくすることができる。 For example, when the heat sink 30 is made of Al, the coefficient of linear expansion of the heat sink 30 is given by the coefficient of linear expansion of Al (23 ppm / K). The substrate 10 has an insulating layer 11 made of Si 3 N 4 having a thickness of 0.32 mm, a front surface conductor layer 12 made of a Cu plate having a thickness of 0.50 mm, and the like. When composed of the back surface conductor layer 13 formed of a Cu plate having a thickness of 0.50 mm, the linear expansion coefficient of the substrate 10 is about 7 ppm / K or more and about 8 ppm / K or less. Therefore, the difference in linear expansion coefficient between the substrate 10 and the heat sink 30 becomes large. When the difference in coefficient of linear expansion between the substrate 10 and the heat sink 30 is large, it is preferable to use a joining member having a large 0.2% proof stress as the joining member 14. A joining member having a large 0.2% proof stress can reduce the crack growth rate (crack growth amount per load cycle) of the joining member 14.
　端子台４０は、ヒートシンク３０に取り付けられている。具体的には、端子台４０は、シリコーン系接着剤またはねじを用いて、ヒートシンク３０の天板３１に取り付けられている。 The terminal block 40 is attached to the heat sink 30. Specifically, the terminal block 40 is attached to the top plate 31 of the heat sink 30 using a silicone-based adhesive or screws.
　図２から図６を参照して、本実施の形態のパワー半導体装置１の製造方法を説明する。
　図２に示されるように、本実施の形態のパワー半導体装置１の製造方法は、基板１０上に第１パワー半導体素子２０及び第２パワー半導体素子２５を接合すること（Ｓ１）を備える。具体的には、導電接合部材２３を用いて、第１パワー半導体素子２０の第１裏面電極２２を基板１０のおもて面導体層１２に接合する。導電接合部材２８を用いて、第２パワー半導体素子２５の第２裏面電極２７を基板１０のおもて面導体層１２に接合する。 The manufacturing method of the power semiconductor device 1 of the present embodiment will be described with reference to FIGS. 2 to 6.
As shown in FIG. 2, the manufacturing method of the power semiconductor device 1 of the present embodiment includes joining the first power semiconductor element 20 and the second power semiconductor element 25 on the substrate 10 (S1). Specifically, the conductive bonding member 23 is used to bond the first back electrode 22 of the first power semiconductor element 20 to the front surface conductor layer 12 of the substrate 10. The second back electrode 27 of the second power semiconductor element 25 is joined to the front surface conductor layer 12 of the substrate 10 by using the conductive bonding member 28.
　図２に示されるように、本実施の形態のパワー半導体装置１の製造方法は、端子台４０をヒートシンク３０に取り付けること（Ｓ２）を備える。具体的には、例えば、シリコーン系接着剤またはねじを用いて、端子台４０をヒートシンク３０の天板３１に取り付ける。引き出し配線４１，４１ｇの一部は、端子台４０に埋め込まれている。引き出し配線４１，４１ｇの残部は、端子台４０から露出している。 As shown in FIG. 2, the manufacturing method of the power semiconductor device 1 of the present embodiment includes attaching the terminal block 40 to the heat sink 30 (S2). Specifically, for example, the terminal block 40 is attached to the top plate 31 of the heat sink 30 using a silicone-based adhesive or screws. A part of the lead- out wiring 41, 41 g is embedded in the terminal block 40. The rest of the lead- out wiring 41, 41 g is exposed from the terminal block 40.
　図２に示されるように、本実施の形態のパワー半導体装置１の製造方法は、基板１０をヒートシンク３０に接合すること（Ｓ３）を備える。具体的には、接合部材１４を用いて、基板１０の裏面導体層１３をヒートシンク３０に取り付ける。接合部材１４は、例えば、アルミ珪素（ＡｌＳｉ）ロウ材、または、Ｓｎを主成分として含むはんだである。 As shown in FIG. 2, the manufacturing method of the power semiconductor device 1 of the present embodiment includes joining the substrate 10 to the heat sink 30 (S3). Specifically, the back surface conductor layer 13 of the substrate 10 is attached to the heat sink 30 by using the joining member 14. The joining member 14 is, for example, an aluminum silicon (AlSi) brazing material or a solder containing Sn as a main component.
　図２に示されるように、本実施の形態のパワー半導体装置１の製造方法は、板状端子５０を、第１パワー半導体素子２０、第２パワー半導体素子２５及び引き出し配線４１に接合すること（Ｓ４）を備える。 As shown in FIG. 2, in the manufacturing method of the power semiconductor device 1 of the present embodiment, the plate-shaped terminal 50 is joined to the first power semiconductor element 20, the second power semiconductor element 25, and the lead-out wiring 41 ( S4) is provided.
　具体的には、図３に示されるように、第１導電接合部材５５、第２導電接合部材５７、第３導電接合部材５６を、それぞれ、第１パワー半導体素子２０の第１おもて面電極２１上、端子台４０から露出している引き出し配線４１の部分上、第２パワー半導体素子２５の第２おもて面電極２６上に載置する（Ｓ４１）。第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は、棒はんだ、板はんだまたはシートはんだのようなバルクはんだ材を用いてもよい。バルクはんだ材を用いることにより、はんだの量を正確に調整することができる。バルクはんだ材はフラックスレスはんだ材であってもよい。フラックスレスはんだ材を用いることにより、はんだ付け後のフラックス残渣の洗浄工程が不要になる。 Specifically, as shown in FIG. 3, the first conductive bonding member 55, the second conductive bonding member 57, and the third conductive bonding member 56 are each the first front surface of the first power semiconductor element 20. It is placed on the second front surface electrode 26 of the second power semiconductor element 25 on the electrode 21 and on the portion of the lead-out wiring 41 exposed from the terminal block 40 (S41). Bulk solder materials such as bar solder, plate solder, and sheet solder may be used for the first conductive joint member 55, the second conductive joint member 57, and the third conductive joint member 56. By using the bulk solder material, the amount of solder can be adjusted accurately. The bulk solder material may be a fluxless solder material. By using the fluxless solder material, the step of cleaning the flux residue after soldering becomes unnecessary.
　それから、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６上に、板状端子５０を載置する（Ｓ４２）。 Then, the plate-shaped terminal 50 is placed on the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 (S42).
　具体的には、板状端子５０は、第１端子部分５１と、第２端子部分５２とを含む。板状端子５０は、第１端子部分５１と第２端子部分５２とを接続する第３端子部分５３をさらに含んでもよい。第１端子部分５１は、第２端子部分５２よりも薄い。第３端子部分５３は、第２端子部分５２よりも薄い。板状端子５０は、例えば、以下の工程によって得られる。均一の厚さを有する導電金属板を準備する。導電金属板のうち、第１端子部分５１及び第３端子部分５３に相当する部分を選択的にエッチングする。それから、導電金属板をプレス加工する。こうして、第１端子部分５１、第２端子部分５２及び第３端子部分５３を含む板状端子５０が得られる。 Specifically, the plate-shaped terminal 50 includes a first terminal portion 51 and a second terminal portion 52. The plate-shaped terminal 50 may further include a third terminal portion 53 that connects the first terminal portion 51 and the second terminal portion 52. The first terminal portion 51 is thinner than the second terminal portion 52. The third terminal portion 53 is thinner than the second terminal portion 52. The plate-shaped terminal 50 is obtained, for example, by the following steps. Prepare a conductive metal plate with a uniform thickness. Of the conductive metal plate, the portions corresponding to the first terminal portion 51 and the third terminal portion 53 are selectively etched. Then, the conductive metal plate is pressed. In this way, a plate-shaped terminal 50 including the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53 can be obtained.
　第１端子部分５１は、第１導電接合部材５５及び第３導電接合部材５６上に載置される。第２端子部分５２は、第２導電接合部材５７上に載置される。第１パワー半導体素子２０と第１端子部分５１との間の第１の線膨張係数の差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数の差よりも大きい。第２パワー半導体素子２５と第１端子部分５１との間の第３の線膨張係数の差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数の差よりも大きい。 The first terminal portion 51 is placed on the first conductive joining member 55 and the third conductive joining member 56. The second terminal portion 52 is placed on the second conductive joining member 57. The difference in the first linear expansion coefficient between the first power semiconductor element 20 and the first terminal portion 51 is larger than the difference in the second linear expansion coefficient between the lead wiring 41 and the second terminal portion 52. .. The difference in the third linear expansion coefficient between the second power semiconductor element 25 and the first terminal portion 51 is larger than the difference in the second linear expansion coefficient between the lead wiring 41 and the second terminal portion 52. ..
　それから、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６を加熱する（Ｓ４３）。第１端子部分５１を加熱することによって、第１導電接合部材５５及び第３導電接合部材５６が加熱され、かつ、第２端子部分５２を加熱することによって、第２導電接合部材５７が加熱されてもよい。特定的には、第１導電接合部材５５及び第３導電接合部材５６（または第１端子部分５１）を加熱しながら、第２導電接合部材５７（または第２端子部分５２）を加熱する。さらに特定的には、第１端子部分５１の第１温度と第２端子部分５２の第２温度とを互いに独立して測定しながら、第１導電接合部材５５及び第３導電接合部材５６（または第１端子部分５１）の加熱を、第２導電接合部材５７（または第２端子部分５２）の加熱とは独立して行う。 Then, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are heated (S43). By heating the first terminal portion 51, the first conductive joint member 55 and the third conductive joint member 56 are heated, and by heating the second terminal portion 52, the second conductive joint member 57 is heated. You may. Specifically, the second conductive joining member 57 (or the second terminal portion 52) is heated while heating the first conductive joining member 55 and the third conductive joining member 56 (or the first terminal portion 51). More specifically, while measuring the first temperature of the first terminal portion 51 and the second temperature of the second terminal portion 52 independently of each other, the first conductive joining member 55 and the third conductive joining member 56 (or The heating of the first terminal portion 51) is performed independently of the heating of the second conductive joining member 57 (or the second terminal portion 52).
　第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は、例えば、鉛フリーはんだである。具体的には、第１導電接合部材５５は、Ｓｎを主成分として含む第１はんだである。第１はんだは、Ｓｎよりも高い０．２％耐力を有している。第１はんだは、例えば、Ｓｎ－Ｃｕ系はんだ、または、Ｓｎ－Ｓｂ系はんだである。第２導電接合部材５７は、Ｓｎを主成分として含む第２はんだである。第２はんだは、Ｓｎよりも高い熱伝導率を有している。第２はんだは、例えば、Ｓｎ－Ａｕ系はんだ、または、Ｓｎ－Ａｇ系はんだである。第３導電接合部材５６は、Ｓｎを主成分として含む第３はんだである。第３はんだは、Ｓｎよりも高い０．２％耐力を有している。第３はんだは、例えば、Ｓｎ－Ｃｕ系はんだ、または、Ｓｎ－Ｓｂ系はんだである。第１導電接合部材５５及び第３導電接合部材５６は、各々、第２導電接合部材５７よりも高い０．２％耐力を有している。第２導電接合部材５７は、第１導電接合部材５５及び第３導電接合部材５６の各々よりも、高い熱伝導率を有している。 The first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are, for example, lead-free solder. Specifically, the first conductive bonding member 55 is a first solder containing Sn as a main component. The first solder has a 0.2% proof stress higher than that of Sn. The first solder is, for example, Sn—Cu-based solder or Sn—Sb-based solder. The second conductive bonding member 57 is a second solder containing Sn as a main component. The second solder has a higher thermal conductivity than Sn. The second solder is, for example, Sn-Au-based solder or Sn-Ag-based solder. The third conductive bonding member 56 is a third solder containing Sn as a main component. The third solder has a 0.2% proof stress higher than that of Sn. The third solder is, for example, Sn—Cu-based solder or Sn—Sb-based solder. The first conductive joining member 55 and the third conductive joining member 56 each have a 0.2% proof stress higher than that of the second conductive joining member 57. The second conductive joint member 57 has a higher thermal conductivity than each of the first conductive joint member 55 and the third conductive joint member 56.
　第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６が鉛フリーはんだのようなはんだである場合、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は、例えば、ハロゲンランプのような赤外線光源から放射される赤外線を用いる輻射熱方式（図４及び図５を参照）、または、ヒートブロックを用いる伝熱方式（図５及び図６を参照）によって、加熱される。板状端子５０の放射率が０．３以上であるとき、輻射熱方式（図４及び図５を参照）によって、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６（第１端子部分５１及び第２端子部分５２）を加熱する。板状端子５０の放射率が０．３未満であるとき、伝熱方式（図５及び図６を参照）によって、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６（第１端子部分５１及び第２端子部分５２）を加熱する。 When the first conductive joining member 55, the second conductive joining member 57 and the third conductive joining member 56 are solders such as lead-free solder, the first conductive joining member 55, the second conductive joining member 57 and the third conductive joining are joined. The member 56 is, for example, a radiant heat method using infrared rays emitted from an infrared light source such as a halogen lamp (see FIGS. 4 and 5) or a heat transfer method using a heat block (see FIGS. 5 and 6). Is heated by. When the emissivity of the plate-shaped terminal 50 is 0.3 or more, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 (see FIGS. 4 and 5) are used by the radiant heat method. The first terminal portion 51 and the second terminal portion 52) are heated. When the emissivity of the plate-shaped terminal 50 is less than 0.3, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are subjected to a heat transfer method (see FIGS. 5 and 6). (1st terminal portion 51 and 2nd terminal portion 52) are heated.
　第一の例では、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は、図４及び図５に示される第１加熱装置６０を用いて、加熱される。第１加熱装置６０は、第１熱源６１と、第２熱源６２と、第１温度センサ６３と、第２温度センサ６４と、制御部６５とを含む。 In the first example, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are heated by using the first heating device 60 shown in FIGS. 4 and 5. The first heating device 60 includes a first heat source 61, a second heat source 62, a first temperature sensor 63, a second temperature sensor 64, and a control unit 65.
　第１熱源６１は、例えば、第１の赤外線ヒータである。第２熱源６２は、例えば、第２の赤外線ヒータである。第１熱源６１は、板状端子５０の第１端子部分５１を加熱して、第１導電接合部材５５及び第３導電接合部材５６を加熱する。第２熱源６２は、板状端子５０の第２端子部分５２を加熱して、第２導電接合部材５７を加熱する。 The first heat source 61 is, for example, a first infrared heater. The second heat source 62 is, for example, a second infrared heater. The first heat source 61 heats the first terminal portion 51 of the plate-shaped terminal 50 to heat the first conductive joint member 55 and the third conductive joint member 56. The second heat source 62 heats the second terminal portion 52 of the plate-shaped terminal 50 to heat the second conductive bonding member 57.
　第１温度センサ６３は、第１の放射温度計である。第２温度センサ６４は、第２の放射温度計である。第１温度センサ６３は、板状端子５０から離間している。第１温度センサ６３は、板状端子５０の第１端子部分５１の第１温度を測定する。第１温度センサ６３は、間接的に、第１導電接合部材５５の温度と第３導電接合部材５６の温度とを測定する。第２温度センサ６４は、板状端子５０から離間している。第２温度センサ６４は、板状端子５０の第２端子部分５２の第２温度を測定する。第２温度センサ６４は、間接的に、第２導電接合部材５７の温度を測定する。板状端子５０の放射率は０．３以上であるため、第１の放射温度計及び第２の放射温度計を用いて、第１端子部分５１の第１温度及び第２端子部分５２の第２温度を正確に測定することができる。 The first temperature sensor 63 is a first radiation thermometer. The second temperature sensor 64 is a second radiation thermometer. The first temperature sensor 63 is separated from the plate-shaped terminal 50. The first temperature sensor 63 measures the first temperature of the first terminal portion 51 of the plate-shaped terminal 50. The first temperature sensor 63 indirectly measures the temperature of the first conductive joint member 55 and the temperature of the third conductive joint member 56. The second temperature sensor 64 is separated from the plate-shaped terminal 50. The second temperature sensor 64 measures the second temperature of the second terminal portion 52 of the plate-shaped terminal 50. The second temperature sensor 64 indirectly measures the temperature of the second conductive joint member 57. Since the emissivity of the plate-shaped terminal 50 is 0.3 or more, the first temperature of the first terminal portion 51 and the second temperature of the second terminal portion 52 are used by using the first radiation thermometer and the second radiation thermometer. 2 Temperature can be measured accurately.
　制御部６５は、第１熱源６１と、第２熱源６２と、第１温度センサ６３と、第２温度センサ６４とに通信可能に接続されている。制御部６５は、第１温度センサ６３を用いて測定される第１端子部分５１の第１温度に基づいて、第１熱源６１を制御する。制御部６５は、第２温度センサ６４を用いて測定される第２端子部分５２の第２温度に基づいて、第２熱源６２を制御する。 The control unit 65 is communicably connected to the first heat source 61, the second heat source 62, the first temperature sensor 63, and the second temperature sensor 64. The control unit 65 controls the first heat source 61 based on the first temperature of the first terminal portion 51 measured by using the first temperature sensor 63. The control unit 65 controls the second heat source 62 based on the second temperature of the second terminal portion 52 measured by using the second temperature sensor 64.
　第１端子部分５１を第１おもて面電極２１に接合する際、第１熱源６１を用いて第１端子部分５１が加熱されて、第１端子部分５１に接触する第１導電接合部材５５及び第３導電接合部材５６が加熱される。第１熱源６１は、第１温度センサ６３を用いて測定される第１端子部分５１の第１温度に基づいて制御される。第２端子部分５２を引き出し配線４１に接合する際、第２熱源６２を用いて第２端子部分５２が加熱されて、第２端子部分５２に接触する第２導電接合部材５７が加熱される。第２熱源６２は、第２温度センサ６４を用いて測定される第２端子部分５２の第２温度に基づいて制御される。 When the first terminal portion 51 is joined to the first front surface electrode 21, the first terminal portion 51 is heated by using the first heat source 61, and the first conductive joining member 55 comes into contact with the first terminal portion 51. And the third conductive bonding member 56 is heated. The first heat source 61 is controlled based on the first temperature of the first terminal portion 51 measured by using the first temperature sensor 63. When the second terminal portion 52 is joined to the lead-out wiring 41, the second terminal portion 52 is heated by using the second heat source 62, and the second conductive joining member 57 in contact with the second terminal portion 52 is heated. The second heat source 62 is controlled based on the second temperature of the second terminal portion 52 measured using the second temperature sensor 64.
　第二の例では、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は、図５及び図６に示される第２加熱装置６０ｂを用いて、加熱される。第２加熱装置６０ｂは、第１熱源６１ｂと、第２熱源６２ｂと、第１温度センサ６３ｂと、第２温度センサ６４ｂと、制御部６５とを含む。 In the second example, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are heated by using the second heating device 60b shown in FIGS. 5 and 6. The second heating device 60b includes a first heat source 61b, a second heat source 62b, a first temperature sensor 63b, a second temperature sensor 64b, and a control unit 65.
　第１熱源６１ｂは、例えば、第１のヒートブロックである。第２熱源６２ｂは、例えば、第２のヒートブロックである。第１熱源６１ｂは、板状端子５０の第１端子部分５１を加熱して、第１導電接合部材５５及び第３導電接合部材５６を加熱する。第２熱源６２ｂは、板状端子５０の第２端子部分５２を加熱して、第２導電接合部材５７を加熱する。 The first heat source 61b is, for example, a first heat block. The second heat source 62b is, for example, a second heat block. The first heat source 61b heats the first terminal portion 51 of the plate-shaped terminal 50 to heat the first conductive bonding member 55 and the third conductive bonding member 56. The second heat source 62b heats the second terminal portion 52 of the plate-shaped terminal 50 to heat the second conductive bonding member 57.
　第１温度センサ６３ｂは、第１の接触式温度計である。第２温度センサ６４ｂは、第２の接触式温度計である。第１温度センサ６３ｂは、板状端子５０の第１端子部分５１に接触して第１端子部分５１の第１温度を測定する。第１温度センサ６３ｂは、間接的に、第１導電接合部材５５の温度と第３導電接合部材５６の温度とを測定する。第２温度センサ６４ｂは、板状端子５０の第２端子部分５２に接触して、第２端子部分５２の第２温度を測定する。第２温度センサ６４ｂは、間接的に、第２導電接合部材５７の温度を測定する。第１の接触式温度計は第１端子部分５１に接触し、第２の接触式温度計は第２端子部分５２に接触するため、板状端子５０の放射率が０．３未満であっても、第１の接触式温度計及び第２の接触式温度計を用いて、第１端子部分５１の第１温度及び第２端子部分５２の第２温度を正確に測定することができる。 The first temperature sensor 63b is a first contact type thermometer. The second temperature sensor 64b is a second contact thermometer. The first temperature sensor 63b contacts the first terminal portion 51 of the plate-shaped terminal 50 and measures the first temperature of the first terminal portion 51. The first temperature sensor 63b indirectly measures the temperature of the first conductive joining member 55 and the temperature of the third conductive joining member 56. The second temperature sensor 64b contacts the second terminal portion 52 of the plate-shaped terminal 50 and measures the second temperature of the second terminal portion 52. The second temperature sensor 64b indirectly measures the temperature of the second conductive joint member 57. Since the first contact thermometer contacts the first terminal portion 51 and the second contact thermometer contacts the second terminal portion 52, the emissivity of the plate-shaped terminal 50 is less than 0.3. Also, the first temperature of the first terminal portion 51 and the second temperature of the second terminal portion 52 can be accurately measured by using the first contact type thermometer and the second contact type thermometer.
　制御部６５は、第１熱源６１ｂと、第２熱源６２ｂと、第１温度センサ６３ｂと、第２温度センサ６４ｂとに通信可能に接続されている。制御部６５は、第１温度センサ６３ｂを用いて測定される第１端子部分５１の第１温度に基づいて、第１熱源６１ｂを制御する。制御部６５は、第２温度センサ６４ｂを用いて測定される第２端子部分５２の第２温度に基づいて、第２熱源６２ｂを制御する。 The control unit 65 is communicably connected to the first heat source 61b, the second heat source 62b, the first temperature sensor 63b, and the second temperature sensor 64b. The control unit 65 controls the first heat source 61b based on the first temperature of the first terminal portion 51 measured by using the first temperature sensor 63b. The control unit 65 controls the second heat source 62b based on the second temperature of the second terminal portion 52 measured by using the second temperature sensor 64b.
　第１端子部分５１を第１おもて面電極２１に接合する際、第１熱源６１ｂを用いて第１端子部分５１が加熱されて、第１端子部分５１に接触する第１導電接合部材５５及び第３導電接合部材５６が加熱される。第１熱源６１ｂは、第１温度センサ６３ｂを用いて測定される第１端子部分５１の第１温度に基づいて制御される。第２端子部分５２を引き出し配線４１に接合する際、第２熱源６２ｂを用いて第２端子部分５２が加熱されて、第２端子部分５２に接触する第２導電接合部材５７が加熱される。第２熱源６２ｂは、第２温度センサ６４ｂを用いて測定される第２端子部分５２の第２温度に基づいて制御される。 When the first terminal portion 51 is joined to the first front surface electrode 21, the first terminal portion 51 is heated by using the first heat source 61b, and the first conductive joining member 55 comes into contact with the first terminal portion 51. And the third conductive bonding member 56 is heated. The first heat source 61b is controlled based on the first temperature of the first terminal portion 51 measured using the first temperature sensor 63b. When the second terminal portion 52 is joined to the lead-out wiring 41, the second terminal portion 52 is heated by using the second heat source 62b, and the second conductive joining member 57 in contact with the second terminal portion 52 is heated. The second heat source 62b is controlled based on the second temperature of the second terminal portion 52 measured using the second temperature sensor 64b.
　それから、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６を冷却する（Ｓ４４）。第１端子部分５１が、第１導電接合部材５５及び第３導電接合部材５６を用いて、第１おもて面電極２１及び第２おもて面電極２６に接合されながら、第２端子部分５２が第２導電接合部材５７を用いて引き出し配線４１に接合される。こうして、板状端子５０は、第１パワー半導体素子２０の第１おもて面電極２１と第２パワー半導体素子２５の第２おもて面電極２６と引き出し配線４１とに接合される。 Then, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are cooled (S44). The second terminal portion 51 is joined to the first front surface electrode 21 and the second front surface electrode 26 by using the first conductive bonding member 55 and the third conductive bonding member 56. 52 is joined to the lead-out wiring 41 by using the second conductive joining member 57. In this way, the plate-shaped terminal 50 is joined to the first front surface electrode 21 of the first power semiconductor element 20, the second front surface electrode 26 of the second power semiconductor element 25, and the lead-out wiring 41.
　なお、板状端子５０を、第１パワー半導体素子２０、第２パワー半導体素子２５及び引き出し配線４１に接合する際（Ｓ４）、板状端子５０ｇは、おもて面導体層１２及び引き出し配線４１ｇに接合される。板状端子５０ｇをおもて面導体層１２及び引き出し配線４１ｇに接合する方法は、板状端子５０を、第１パワー半導体素子２０、第２パワー半導体素子２５及び引き出し配線４１に接合する方法と同様である。 When the plate-shaped terminal 50 is joined to the first power semiconductor element 20, the second power semiconductor element 25, and the lead-out wiring 41 (S4), the plate-shaped terminal 50 g is the front surface conductor layer 12 and the lead-out wiring 41 g. Is joined to. The method of joining the plate-shaped terminal 50 g to the front conductor layer 12 and the lead-out wiring 41 g is a method of joining the plate-shaped terminal 50 to the first power semiconductor element 20, the second power semiconductor element 25, and the lead-out wiring 41. The same is true.
　本実施の形態の作用を説明する。
　本実施の形態では、第１パワー半導体素子２０と第１端子部分５１との間の第１の線膨張係数差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数差よりも大きい。第２パワー半導体素子２５と第１端子部分５１との間の第３の線膨張係数差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数差よりも大きい。例えば、第１パワー半導体素子２０及び第２パワー半導体素子２５が主にＳｉ（線膨張係数２．５ｐｐｍ／Ｋ）で形成されており、かつ、板状端子５０及び引き出し配線４１がＣｕ（線膨張係数１６．８ｐｐｍ／Ｋ）で形成されている場合、第１の線膨張係数差及び第３の線膨張係数差は各々１４．３ｐｐｍ／Ｋであるのに対し、第２の線膨張係数差はゼロである。そのため、第１導電接合部材５５に印加される熱応力は、第２導電接合部材５７に印加される熱応力よりも大きい。第３導電接合部材５６に印加される熱応力は、第２導電接合部材５７に印加される熱応力よりも大きい。パワー半導体装置１の使用中に、第１導電接合部材５５及び第３導電接合部材５６に繰り返し大きな熱応力が印加される。 The operation of this embodiment will be described.
In the present embodiment, the first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52. Greater than the difference. The third linear expansion coefficient difference between the second power semiconductor element 25 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52. For example, the first power semiconductor element 20 and the second power semiconductor element 25 are mainly formed of Si (coefficient of linear expansion 2.5 ppm / K), and the plate-shaped terminal 50 and the lead-out wiring 41 are Cu (linear expansion). When formed with a coefficient of 16.8 ppm / K), the first linear expansion coefficient difference and the third linear expansion coefficient difference are 14.3 ppm / K, respectively, whereas the second linear expansion coefficient difference is It is zero. Therefore, the thermal stress applied to the first conductive bonding member 55 is larger than the thermal stress applied to the second conductive bonding member 57. The thermal stress applied to the third conductive joint member 56 is larger than the thermal stress applied to the second conductive joint member 57. During the use of the power semiconductor device 1, a large thermal stress is repeatedly applied to the first conductive bonding member 55 and the third conductive bonding member 56.
　この熱応力は、第１導電接合部材５５及び第３導電接合部材５６に、き裂を発生及び進展させ、第１導電接合部材５５の断面積と第３導電接合部材５６の断面積とを減少させる。本明細書では、導電接合部材の断面積は、基板１０の主面１０ａに平行な断面における導電接合部材の面積を意味する。第１導電接合部材５５の断面積及び第３導電接合部材５６の断面積の減少により、第１導電接合部材５５の電気抵抗及び第３導電接合部材５６の電気抵抗が増加して、第１導電接合部材５５及び第３導電接合部材５６で発生するジュール熱が増加する。第１導電接合部材５５及び第３導電接合部材５６に印加される熱応力がさらに増加する。第１導電接合部材５５及び第３導電接合部材５６においてき裂がさらに進展して、第１導電接合部材５５及び第３導電接合部材５６が完全に裂けることがある。第１導電接合部材５５及び第３導電接合部材５６が完全に裂けると、第１パワー半導体素子２０の第１おもて面電極２１と引き出し配線４１との間に高い電位差が発生して、第１おもて面電極２１と引き出し配線４１との間にアーク放電が発生する。第２パワー半導体素子２５の第２おもて面電極２６と引き出し配線４１との間に高い電位差が発生して、第２おもて面電極２６と引き出し配線４１との間にアーク放電が発生する。パワー半導体装置１が故障する。 This thermal stress causes and propagates cracks in the first conductive joint member 55 and the third conductive joint member 56, and reduces the cross-sectional area of the first conductive joint member 55 and the cross-sectional area of the third conductive joint member 56. Let me. In the present specification, the cross-sectional area of the conductive joining member means the area of the conductive joining member in the cross section parallel to the main surface 10a of the substrate 10. Due to the decrease in the cross-sectional area of the first conductive joining member 55 and the cross-sectional area of the third conductive joining member 56, the electric resistance of the first conductive joining member 55 and the electric resistance of the third conductive joining member 56 increase, and the first conductive Joule heat generated by the joining member 55 and the third conductive joining member 56 increases. The thermal stress applied to the first conductive joint member 55 and the third conductive joint member 56 is further increased. Cracks may further develop in the first conductive joint member 55 and the third conductive joint member 56, and the first conductive joint member 55 and the third conductive joint member 56 may be completely torn. When the first conductive joining member 55 and the third conductive joining member 56 are completely torn, a high potential difference is generated between the first front surface electrode 21 of the first power semiconductor element 20 and the lead-out wiring 41, and the first 1 An arc discharge is generated between the front surface electrode 21 and the lead-out wiring 41. A high potential difference is generated between the second front surface electrode 26 of the second power semiconductor element 25 and the lead-out wiring 41, and an arc discharge is generated between the second front surface electrode 26 and the lead-out wiring 41. To do. The power semiconductor device 1 fails.
　しかし、第１端子部分５１は、第２端子部分５２よりも薄い。そのため、第１導電接合部材５５及び第３導電接合部材５６に印加される熱応力を小さくすることができる。第１導電接合部材５５及び第３導電接合部材５６にき裂が発生すること、及び、第１おもて面電極２１及び第２おもて面電極２６から第１端子部分５１がはく離することが防止される。 However, the first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the thermal stress applied to the first conductive joining member 55 and the third conductive joining member 56 can be reduced. Cracks occur in the first conductive joint member 55 and the third conductive joint member 56, and the first terminal portion 51 is separated from the first front surface electrode 21 and the second front surface electrode 26. Is prevented.
　また、第１パワー半導体素子２０及び第２パワー半導体素子２５で発生した熱が、板状端子５０を介して、第２導電接合部材５７に伝わる。そのため、第２導電接合部材５７の温度が上昇する。加えて、第２導電接合部材５７は、引き出し配線４１に接触しており、引き出し配線４１の一部は絶縁樹脂製の端子台４０に埋め込まれている。そのため、第２導電接合部材５７の温度は上昇しやすい。第２導電接合部材５７の温度が上昇すると、第２導電接合部材５７が劣化する。例えば、第２導電接合部材５７の温度が上昇すると、第２導電接合部材５７に含まれる結晶粒が大きくなって、第２導電接合部材５７が金属疲労を起こすことがある。本実施の形態では、第２端子部分５２は、第１端子部分５１よりも厚い。第２端子部分５２は、第１端子部分５１よりも大きな熱容量を有する。そのため、第２導電接合部材５７の温度上昇を低減することができる。第２導電接合部材５７の劣化が低減される。 Further, the heat generated in the first power semiconductor element 20 and the second power semiconductor element 25 is transferred to the second conductive bonding member 57 via the plate-shaped terminal 50. Therefore, the temperature of the second conductive joining member 57 rises. In addition, the second conductive joining member 57 is in contact with the lead-out wiring 41, and a part of the lead-out wiring 41 is embedded in the terminal block 40 made of insulating resin. Therefore, the temperature of the second conductive bonding member 57 tends to rise. When the temperature of the second conductive joint member 57 rises, the second conductive joint member 57 deteriorates. For example, when the temperature of the second conductive bonding member 57 rises, the crystal grains contained in the second conductive bonding member 57 become large, and the second conductive bonding member 57 may cause metal fatigue. In the present embodiment, the second terminal portion 52 is thicker than the first terminal portion 51. The second terminal portion 52 has a larger heat capacity than the first terminal portion 51. Therefore, the temperature rise of the second conductive bonding member 57 can be reduced. Deterioration of the second conductive joint member 57 is reduced.
　本実施の形態のパワー半導体装置１及びその製造方法の効果を説明する。
　本実施の形態のパワー半導体装置１は、基板１０と、第１パワー半導体素子２０と、引き出し配線４１と、板状端子５０とを備える。第１パワー半導体素子２０は、基板１０に接合されている第１裏面電極２２と、第１裏面電極２２とは反対側の第１おもて面電極２１とを含む。板状端子５０は、第１端子部分５１と、第２端子部分５２とを含む。第１端子部分５１は、第１導電接合部材５５を用いて第１おもて面電極２１に接合されている。第２端子部分５２は、第２導電接合部材５７を用いて引き出し配線４１に接合されている。第１パワー半導体素子２０と第１端子部分５１との間の第１の線膨張係数差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数差よりも大きい。第１端子部分５１は、第２端子部分５２よりも薄い。 The effects of the power semiconductor device 1 of the present embodiment and the manufacturing method thereof will be described.
The power semiconductor device 1 of the present embodiment includes a substrate 10, a first power semiconductor element 20, a lead-out wiring 41, and a plate-shaped terminal 50. The first power semiconductor element 20 includes a first back surface electrode 22 bonded to the substrate 10 and a first front surface electrode 21 on the opposite side of the first back surface electrode 22. The plate-shaped terminal 50 includes a first terminal portion 51 and a second terminal portion 52. The first terminal portion 51 is bonded to the first front surface electrode 21 by using the first conductive bonding member 55. The second terminal portion 52 is joined to the lead-out wiring 41 by using the second conductive joining member 57. The first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52. The first terminal portion 51 is thinner than the second terminal portion 52.
　第１パワー半導体素子２０と第１端子部分５１との間の第１の線膨張係数差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数差よりも大きい。そのため、第１導電接合部材５５に印加される熱応力は、第２導電接合部材５７に印加される熱応力よりも大きい。しかし、第１端子部分５１は、第２端子部分５２よりも薄い。そのため、第１導電接合部材５５に印加される熱応力を小さくすることができる。第１導電接合部材５５にき裂が発生すること、及び、第１端子部分５１が第１おもて面電極２１からはく離することが防止される。さらに、第２端子部分５２は、第１端子部分５１よりも厚い。第２端子部分５２は、第１端子部分５１よりも大きな熱容量を有する。そのため、第２導電接合部材５７の温度上昇が低減されて、第２導電接合部材５７の劣化が低減される。パワー半導体装置１の信頼性が向上され得る。 The first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52. Therefore, the thermal stress applied to the first conductive bonding member 55 is larger than the thermal stress applied to the second conductive bonding member 57. However, the first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the thermal stress applied to the first conductive bonding member 55 can be reduced. It is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21. Further, the second terminal portion 52 is thicker than the first terminal portion 51. The second terminal portion 52 has a larger heat capacity than the first terminal portion 51. Therefore, the temperature rise of the second conductive joint member 57 is reduced, and the deterioration of the second conductive joint member 57 is reduced. The reliability of the power semiconductor device 1 can be improved.
　第２端子部分５２の第２厚さｔ2に対する第１端子部分５１の第１厚さｔ1の比は、０．１０以上０．７５以下である。この比が０．７５以下であるため、第１導電接合部材５５に印加される熱応力を小さくすることができる。この比が０．１０以上であるため、第１端子部分５１の電気抵抗に起因する第１端子部分５１の発熱が低減され得る。第１導電接合部材５５の温度上昇を低減することができて、第１導電接合部材５５の劣化が低減される。パワー半導体装置１の信頼性が向上され得る。 The ratio of the first thickness t 1 of the first terminal portion 51 to the second thickness t 2 of the second terminal portion 52 is 0.10 or more and 0.75 or less. Since this ratio is 0.75 or less, the thermal stress applied to the first conductive bonding member 55 can be reduced. Since this ratio is 0.10 or more, heat generation of the first terminal portion 51 due to the electric resistance of the first terminal portion 51 can be reduced. The temperature rise of the first conductive joining member 55 can be reduced, and the deterioration of the first conductive joining member 55 is reduced. The reliability of the power semiconductor device 1 can be improved.
　本実施の形態のパワー半導体装置１では、第１端子部分５１の第１厚さｔ1は、０．１５ｍｍ以上０．６０ｍｍ以下である。第２端子部分５２の第２厚さｔ2は、０．８０ｍｍ以上１．５０ｍｍ以下である。 In the power semiconductor device 1 of the present embodiment, the first thickness t 1 of the first terminal portion 51 is 0.15 mm or more and 0.60 mm or less. The second thickness t 2 of the second terminal portion 52 is 0.80 mm or more and 1.50 mm or less.
　第１端子部分５１の第１厚さｔ1が０．６０ｍｍ以下であるため、第１導電接合部材５５に印加される熱応力を小さくすることができる。第１導電接合部材５５にき裂が発生すること、及び、第１端子部分５１が第１おもて面電極２１からはく離することが防止される。第１端子部分５１の第１厚さｔ1が０．１５ｍｍ以上であるため、第１端子部分５１の電気抵抗に起因する第１端子部分５１の発熱が低減され得る。第１導電接合部材５５の温度上昇を低減することができて、第１導電接合部材５５の劣化が低減される。第２端子部分５２の第２厚さｔ2が０．８０ｍｍ以上であるため、第２導電接合部材５７の温度上昇を低減することができて、第２導電接合部材５７の劣化が低減される。第２端子部分５２の第２厚さｔ2が１．５０ｍｍ以下であるため、第２端子部分５２から第２導電接合部材５７に印加される機械的歪が低減され得る。パワー半導体装置１の信頼性が向上され得る。 Since the first thickness t 1 of the first terminal portion 51 is 0.60 mm or less, the thermal stress applied to the first conductive joint member 55 can be reduced. It is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21. Since the first thickness t 1 of the first terminal portion 51 is 0.15 mm or more, heat generation of the first terminal portion 51 due to the electric resistance of the first terminal portion 51 can be reduced. The temperature rise of the first conductive joining member 55 can be reduced, and the deterioration of the first conductive joining member 55 is reduced. Since the second thickness t 2 of the second terminal portion 52 is 0.80 mm or more, the temperature rise of the second conductive joint member 57 can be reduced, and the deterioration of the second conductive joint member 57 is reduced. .. Since the second thickness t 2 of the second terminal portion 52 is 1.50 mm or less, the mechanical strain applied from the second terminal portion 52 to the second conductive joint member 57 can be reduced. The reliability of the power semiconductor device 1 can be improved.
　本実施の形態のパワー半導体装置１では、第１導電接合部材５５は、金属微粒子焼結体で形成されている。一般に、金属微粒子焼結体は、微粒子を構成する金属が有する高い融点を有している。そのため、第１パワー半導体素子２０が高温で動作しても、第１導電接合部材５５の劣化が低減される。パワー半導体装置１の信頼性が向上され得る。 In the power semiconductor device 1 of the present embodiment, the first conductive bonding member 55 is formed of a metal fine particle sintered body. Generally, the metal fine particle sintered body has a high melting point of the metal constituting the fine particles. Therefore, even if the first power semiconductor element 20 operates at a high temperature, the deterioration of the first conductive bonding member 55 is reduced. The reliability of the power semiconductor device 1 can be improved.
　本実施の形態のパワー半導体装置１では、第１導電接合部材５５は、Ｓｎを主成分として含む第１はんだである。第１はんだは、Ｓｎよりも高い０．２％耐力を有している。第２導電接合部材５７は、Ｓｎを主成分として含む第２はんだである。第２はんだは、Ｓｎよりも高い熱伝導率を有している。 In the power semiconductor device 1 of the present embodiment, the first conductive bonding member 55 is the first solder containing Sn as a main component. The first solder has a 0.2% proof stress higher than that of Sn. The second conductive bonding member 57 is a second solder containing Sn as a main component. The second solder has a higher thermal conductivity than Sn.
　第１導電接合部材５５は、第２導電接合部材５７よりも、高い０．２％耐力を有している。そのため、第１導電接合部材５５にき裂が発生すること、及び、第１端子部分５１が第１おもて面電極２１からはく離することが防止される。第２導電接合部材５７は、第１導電接合部材５５よりも高い熱伝導率を有している。そのため、第２導電接合部材５７の温度上昇を低減することができて、第２導電接合部材５７の劣化が低減される。パワー半導体装置１の信頼性が向上され得る。 The first conductive joining member 55 has a higher 0.2% proof stress than the second conductive joining member 57. Therefore, it is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21. The second conductive joint member 57 has a higher thermal conductivity than the first conductive joint member 55. Therefore, the temperature rise of the second conductive joining member 57 can be reduced, and the deterioration of the second conductive joining member 57 is reduced. The reliability of the power semiconductor device 1 can be improved.
　さらに、第１導電接合部材５５と第２導電接合部材５７とは、Ｓｎを主成分として含むはんだである点で共通している。そのため、第１導電接合部材５５を用いた第１端子部分５１と第１おもて面電極２１との接合と、第２導電接合部材５７を用いた第２端子部分５２と引き出し配線４１との接合とは、同一の工程で形成され得る。パワー半導体装置１は、パワー半導体装置１の生産性の向上が可能な構成を備えている。 Further, the first conductive joining member 55 and the second conductive joining member 57 are common in that they are solders containing Sn as a main component. Therefore, the first terminal portion 51 using the first conductive joining member 55 and the first front surface electrode 21 are joined, and the second terminal portion 52 using the second conductive joining member 57 and the lead-out wiring 41 are joined. Joining can be formed in the same process. The power semiconductor device 1 has a configuration capable of improving the productivity of the power semiconductor device 1.
　本実施の形態のパワー半導体装置１では、引き出し配線４１は、第１端子部分５１と第２端子部分５２とを接続する第３端子部分５３をさらに含む。第３端子部分５３は、第１裏面電極２２と第１おもて面電極２１とが互いに離間している第１パワー半導体素子２０の厚さ方向（第３方向（ｚ方向））に沿って延在している。 In the power semiconductor device 1 of the present embodiment, the lead-out wiring 41 further includes a third terminal portion 53 that connects the first terminal portion 51 and the second terminal portion 52. The third terminal portion 53 is formed along the thickness direction (third direction (z direction)) of the first power semiconductor element 20 in which the first back surface electrode 22 and the first front surface electrode 21 are separated from each other. It is postponed.
　そのため、第１パワー半導体素子２０の厚さ方向（第３方向（ｚ方向））における、第１おもて面電極２１の高さが引き出し配線４１の高さと異なることに起因して板状端子５０から第１導電接合部材５５及び第２導電接合部材５７に印加される機械的応力が、低減される。第１導電接合部材５５及び第２導電接合部材５７にき裂が発生すること、第１端子部分５１が第１おもて面電極２１からはく離すること、及び、第２端子部分５２が引き出し配線４１からはく離することが防止される。パワー半導体装置１の信頼性が向上され得る。 Therefore, the plate-shaped terminal is caused by the fact that the height of the first front surface electrode 21 in the thickness direction (third direction (z direction)) of the first power semiconductor element 20 is different from the height of the lead-out wiring 41. The mechanical stress applied to the first conductive joining member 55 and the second conductive joining member 57 from 50 is reduced. Cracks occur in the first conductive joint member 55 and the second conductive joint member 57, the first terminal portion 51 is separated from the first front surface electrode 21, and the second terminal portion 52 is a lead-out wiring. It is prevented from peeling off from 41. The reliability of the power semiconductor device 1 can be improved.
　本実施の形態のパワー半導体装置１は、絶縁樹脂製の端子台４０をさらに備える。引き出し配線４１の一部は端子台４０に埋め込まれている。第２端子部分５２は、第２導電接合部材５７を用いて、端子台４０から露出している引き出し配線４１の部分に接合されている。端子台４０の熱伝導率は、引き出し配線４１の熱伝導率よりも小さく、かつ、板状端子５０の熱伝導率よりも小さい。 The power semiconductor device 1 of the present embodiment further includes a terminal block 40 made of an insulating resin. A part of the lead-out wiring 41 is embedded in the terminal block 40. The second terminal portion 52 is joined to the portion of the lead-out wiring 41 exposed from the terminal block 40 by using the second conductive joining member 57. The thermal conductivity of the terminal block 40 is smaller than the thermal conductivity of the lead-out wiring 41 and smaller than the thermal conductivity of the plate-shaped terminal 50.
　引き出し配線４１の一部が相対的に低い熱伝導率を有する端子台４０に埋め込まれている。そのため、引き出し配線４１に接合されている第２導電接合部材５７の温度は上昇しやすい。しかし、第２端子部分５２は第１端子部分５１よりも厚い。そのため、第２導電接合部材５７の温度上昇を低減することができて、第２導電接合部材５７の劣化が低減される。パワー半導体装置１の信頼性が向上され得る。 A part of the lead-out wiring 41 is embedded in the terminal block 40 having a relatively low thermal conductivity. Therefore, the temperature of the second conductive joining member 57 joined to the lead-out wiring 41 tends to rise. However, the second terminal portion 52 is thicker than the first terminal portion 51. Therefore, the temperature rise of the second conductive joining member 57 can be reduced, and the deterioration of the second conductive joining member 57 is reduced. The reliability of the power semiconductor device 1 can be improved.
　本実施の形態のパワー半導体装置１は、第２パワー半導体素子２５をさらに備える。第２パワー半導体素子２５は、基板１０に接合されている第２裏面電極２７と、第２裏面電極２７とは反対側の第２おもて面電極２６とを含む。第１端子部分５１は、第３導電接合部材５６を用いて第２おもて面電極２６に接合されている。第２パワー半導体素子２５と第１端子部分５１との間の第３の線膨張係数差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数差よりも大きい。 The power semiconductor device 1 of the present embodiment further includes a second power semiconductor element 25. The second power semiconductor element 25 includes a second back surface electrode 27 bonded to the substrate 10 and a second front surface electrode 26 on the opposite side of the second back surface electrode 27. The first terminal portion 51 is bonded to the second front surface electrode 26 by using the third conductive bonding member 56. The third linear expansion coefficient difference between the second power semiconductor element 25 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52.
　第２パワー半導体素子２５と第１端子部分５１との間の第３の線膨張係数差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数差よりも大きい。そのため、第３導電接合部材５６に印加される熱応力は、第２導電接合部材５７に印加される熱応力よりも大きい。しかし、第１端子部分５１は、第２端子部分５２よりも薄い。そのため、第３導電接合部材５６に印加される熱応力を小さくすることができる。第３導電接合部材５６にき裂が発生すること、及び、第１端子部分５１が第２おもて面電極２６からはく離することが防止される。パワー半導体装置１の信頼性が向上され得る。 The third linear expansion coefficient difference between the second power semiconductor element 25 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead-out wiring 41 and the second terminal portion 52. Therefore, the thermal stress applied to the third conductive joint member 56 is larger than the thermal stress applied to the second conductive joint member 57. However, the first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the thermal stress applied to the third conductive joint member 56 can be reduced. It is possible to prevent the third conductive bonding member 56 from being cracked and the first terminal portion 51 from being separated from the second front surface electrode 26. The reliability of the power semiconductor device 1 can be improved.
　さらに、第１パワー半導体素子２０と第２パワー半導体素子２５とは、ともに、一つの板状端子５０に接合されている。そのため、配線インダクタンスを小さくすることができて、第１パワー半導体素子２０及び第２パワー半導体素子２５に印加されるサージ電圧を小さくすることができる。また、板状端子５０と第１パワー半導体素子２０との接合と、板状端子５０と第２パワー半導体素子２５との接合とを、一回の工程で行うことができる。パワー半導体装置１は、パワー半導体装置１の生産性を向上させることが可能な構造を有している。 Further, both the first power semiconductor element 20 and the second power semiconductor element 25 are joined to one plate-shaped terminal 50. Therefore, the wiring inductance can be reduced, and the surge voltage applied to the first power semiconductor element 20 and the second power semiconductor element 25 can be reduced. Further, the joining of the plate-shaped terminal 50 and the first power semiconductor element 20 and the joining of the plate-shaped terminal 50 and the second power semiconductor element 25 can be performed in one step. The power semiconductor device 1 has a structure capable of improving the productivity of the power semiconductor device 1.
　本実施の形態のパワー半導体装置１の製造方法は、第１パワー半導体素子２０の第１裏面電極２２を基板１０に接合すること（Ｓ１）と、板状端子５０を、第１裏面電極２２とは反対側の第１パワー半導体素子２０の第１おもて面電極２１と引き出し配線４１とに接合すること（Ｓ４）とを備える。板状端子５０は、第１端子部分５１と、第２端子部分５２とを含む。第１パワー半導体素子２０と第１端子部分５１との間の第１の線膨張係数の差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数の差よりも大きい。第１端子部分５１は、第２端子部分５２よりも薄い。 In the method of manufacturing the power semiconductor device 1 of the present embodiment, the first back electrode 22 of the first power semiconductor element 20 is bonded to the substrate 10 (S1), and the plate-shaped terminal 50 is attached to the first back electrode 22. Is provided with joining (S4) to the first front surface electrode 21 of the first power semiconductor element 20 on the opposite side and the lead-out wiring 41. The plate-shaped terminal 50 includes a first terminal portion 51 and a second terminal portion 52. The difference in the first linear expansion coefficient between the first power semiconductor element 20 and the first terminal portion 51 is larger than the difference in the second linear expansion coefficient between the lead wiring 41 and the second terminal portion 52. .. The first terminal portion 51 is thinner than the second terminal portion 52.
　第１端子部分５１が第１導電接合部材５５を用いて第１おもて面電極２１に接合されながら、第２端子部分５２は第２導電接合部材５７を用いて引き出し配線４１に接合される。第１端子部分５１を第１おもて面電極２１に接合する際、第１導電接合部材５５は第１熱源６１，６１ｂを用いて加熱される。第１熱源６１，６１ｂは、第１温度センサ６３，６３ｂを用いて測定される第１端子部分５１の第１温度に基づいて制御される。第２端子部分５２を引き出し配線４１に接合する際、第２導電接合部材５７は第２熱源６２，６２ｂを用いて加熱される。第２熱源６２，６２ｂは、第２温度センサ６４，６４ｂを用いて測定される第２端子部分５２の第２温度に基づいて制御される。 While the first terminal portion 51 is bonded to the first front surface electrode 21 using the first conductive bonding member 55, the second terminal portion 52 is bonded to the lead-out wiring 41 using the second conductive bonding member 57. .. When the first terminal portion 51 is joined to the first front surface electrode 21, the first conductive joining member 55 is heated by using the first heat sources 61 and 61b. The first heat sources 61 and 61b are controlled based on the first temperature of the first terminal portion 51 measured using the first temperature sensors 63 and 63b. When the second terminal portion 52 is joined to the lead-out wiring 41, the second conductive joining member 57 is heated by using the second heat sources 62 and 62b. The second heat sources 62 and 62b are controlled based on the second temperature of the second terminal portion 52 measured using the second temperature sensors 64 and 64b.
　第１パワー半導体素子２０と第１端子部分５１との間の第１の線膨張係数差は、引き出し配線４１と第２端子部分５２との間の第２の線膨張係数差よりも大きい。そのため、第１導電接合部材５５に印加される熱応力は、第２導電接合部材５７に印加される熱応力よりも大きい。しかし、第１端子部分５１は、第２端子部分５２よりも薄い。そのため、第１導電接合部材５５に印加される熱応力を小さくすることができる。第１導電接合部材５５にき裂が発生すること、及び、第１端子部分５１が第１おもて面電極２１からはく離することが防止される。さらに、第２端子部分５２は、第１端子部分５１よりも厚い。第２端子部分５２は、第１端子部分５１よりも大きな熱容量を有する。そのため、第２導電接合部材５７の温度上昇を低減することができて、第２導電接合部材５７の劣化が低減される。本実施の形態のパワー半導体装置１の製造方法によれば、信頼性が向上されたパワー半導体装置１を得ることができる。 The first linear expansion coefficient difference between the first power semiconductor element 20 and the first terminal portion 51 is larger than the second linear expansion coefficient difference between the lead wiring 41 and the second terminal portion 52. Therefore, the thermal stress applied to the first conductive bonding member 55 is larger than the thermal stress applied to the second conductive bonding member 57. However, the first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the thermal stress applied to the first conductive bonding member 55 can be reduced. It is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21. Further, the second terminal portion 52 is thicker than the first terminal portion 51. The second terminal portion 52 has a larger heat capacity than the first terminal portion 51. Therefore, the temperature rise of the second conductive joining member 57 can be reduced, and the deterioration of the second conductive joining member 57 is reduced. According to the method for manufacturing the power semiconductor device 1 of the present embodiment, the power semiconductor device 1 with improved reliability can be obtained.
　第２端子部分５２は、第１端子部分５１よりも厚い。第２端子部分５２の第２熱容量は、第１端子部分５１の第１熱容量よりも大きい。第１端子部分５１及び第２端子部分５２を加熱したときに、第２端子部分５２は、第１端子部分５１よりも温度が上昇しにくい。そのため、第２導電接合部材５７を用いた引き出し配線４１と第２端子部分５２との接合が不良になることがある。しかし、本実施の形態のパワー半導体装置１の製造方法では、第１端子部分５１に接触する第１導電接合部材５５は第１熱源６１，６１ｂを用いて加熱されており、第２端子部分５２に接触する第２導電接合部材５７は、第１熱源６１，６１ｂとは別の第２熱源６２，６２ｂを用いて加熱されている。さらに、第１熱源６１，６１ｂは、第１温度センサ６３，６３ｂを用いて測定される第１端子部分５１の第１温度に基づいて制御されるのに対し、第２熱源６２，６２ｂは、第１温度センサ６３，６３ｂとは別の第２温度センサ６４，６４ｂを用いて測定される第２端子部分５２の第２温度に基づいて制御される。 The second terminal portion 52 is thicker than the first terminal portion 51. The second heat capacity of the second terminal portion 52 is larger than the first heat capacity of the first terminal portion 51. When the first terminal portion 51 and the second terminal portion 52 are heated, the temperature of the second terminal portion 52 is less likely to rise than that of the first terminal portion 51. Therefore, the connection between the lead-out wiring 41 using the second conductive joining member 57 and the second terminal portion 52 may be poor. However, in the manufacturing method of the power semiconductor device 1 of the present embodiment, the first conductive bonding member 55 in contact with the first terminal portion 51 is heated by using the first heat sources 61 and 61b, and the second terminal portion 52 The second conductive bonding member 57 in contact with the first heat source 61, 61b is heated by using a second heat source 62, 62b different from the first heat sources 61, 61b. Further, the first heat sources 61, 61b are controlled based on the first temperature of the first terminal portion 51 measured by using the first temperature sensors 63, 63b, whereas the second heat sources 62, 62b are controlled. It is controlled based on the second temperature of the second terminal portion 52 measured by using the second temperature sensors 64, 64b different from the first temperature sensors 63, 63b.
　このように、本実施の形態のパワー半導体装置１の製造方法では、第２端子部分５２の第２温度は、第１端子部分５１の第１温度とは独立して測定され、かつ、第２端子部分５２は第１端子部分５１とは独立して加熱されている。そのため、第２端子部分５２が第１端子部分５１よりも厚くても、第１端子部分５１に接触する第１導電接合部材５５と第２端子部分５２に接触する第２導電接合部材５７とは適切に加熱され得る。第１おもて面電極２１と第１端子部分５１とは第１導電接合部材５５を用いて互いに良好に接合され、かつ、引き出し配線４１と第２端子部分５２とは第２導電接合部材５７を用いて互いに良好に接合される。本実施の形態のパワー半導体装置１の製造方法によれば、信頼性が向上されたパワー半導体装置１を得ることができる。 As described above, in the manufacturing method of the power semiconductor device 1 of the present embodiment, the second temperature of the second terminal portion 52 is measured independently of the first temperature of the first terminal portion 51, and is the second. The terminal portion 52 is heated independently of the first terminal portion 51. Therefore, even if the second terminal portion 52 is thicker than the first terminal portion 51, the first conductive joining member 55 in contact with the first terminal portion 51 and the second conductive joining member 57 in contact with the second terminal portion 52 are Can be heated properly. The first front surface electrode 21 and the first terminal portion 51 are satisfactorily joined to each other by using the first conductive joining member 55, and the lead-out wiring 41 and the second terminal portion 52 are joined to each other by the second conductive joining member 57. Are well joined to each other using. According to the method for manufacturing the power semiconductor device 1 of the present embodiment, the power semiconductor device 1 with improved reliability can be obtained.
　本実施の形態のパワー半導体装置１の製造方法では、第１導電接合部材５５は、Ｓｎを主成分として含む第１はんだである。第１はんだはＳｎよりも高い０．２％耐力を有している。第２導電接合部材５７は、Ｓｎを主成分として含む第２はんだである。第２はんだはＳｎよりも高い熱伝導率を有している。 In the method for manufacturing the power semiconductor device 1 of the present embodiment, the first conductive bonding member 55 is a first solder containing Sn as a main component. The first solder has a 0.2% proof stress higher than that of Sn. The second conductive bonding member 57 is a second solder containing Sn as a main component. The second solder has a higher thermal conductivity than Sn.
　第１導電接合部材５５は、第２導電接合部材５７よりも高い０．２％耐力を有している。そのため、第１導電接合部材５５にき裂が発生すること、及び、第１端子部分５１が第１おもて面電極２１からはく離することが防止される。また、第２導電接合部材５７は、第１導電接合部材５５よりも高い熱伝導率を有している。そのため、第２導電接合部材５７の温度上昇を低減することができて、第２導電接合部材５７の劣化が低減される。本実施の形態のパワー半導体装置１の製造方法によれば、信頼性が向上されたパワー半導体装置１を得ることができる。 The first conductive joining member 55 has a higher 0.2% proof stress than the second conductive joining member 57. Therefore, it is possible to prevent the first conductive bonding member 55 from being cracked and the first terminal portion 51 from being separated from the first front surface electrode 21. Further, the second conductive joining member 57 has a higher thermal conductivity than the first conductive joining member 55. Therefore, the temperature rise of the second conductive joining member 57 can be reduced, and the deterioration of the second conductive joining member 57 is reduced. According to the method for manufacturing the power semiconductor device 1 of the present embodiment, the power semiconductor device 1 with improved reliability can be obtained.
　さらに、第１導電接合部材５５と第２導電接合部材５７とは、Ｓｎを主成分として含むはんだである点で共通している。そのため、第１導電接合部材５５を用いた第１端子部分５１と第１おもて面電極２１との接合と、第２導電接合部材５７を用いた第２端子部分５２と引き出し配線４１との接合とは、同一の工程で形成され得る。本実施の形態のパワー半導体装置１の製造方法によれば、向上された生産性でパワー半導体装置１を得ることができる。 Further, the first conductive joining member 55 and the second conductive joining member 57 are common in that they are solders containing Sn as a main component. Therefore, the first terminal portion 51 using the first conductive joining member 55 and the first front surface electrode 21 are joined, and the second terminal portion 52 using the second conductive joining member 57 and the lead-out wiring 41 are joined. Joining can be formed in the same process. According to the method for manufacturing the power semiconductor device 1 of the present embodiment, the power semiconductor device 1 can be obtained with improved productivity.
　実施の形態２．
　図７を参照して、実施の形態２のパワー半導体装置１ｂを説明する。本実施の形態のパワー半導体装置１ｂは、実施の形態１のパワー半導体装置１と同様の構成を備えるが、以下の点で主に異なる。 Embodiment 2.
The power semiconductor device 1b of the second embodiment will be described with reference to FIG. 7. The power semiconductor device 1b of the present embodiment has the same configuration as the power semiconductor device 1 of the first embodiment, but is mainly different in the following points.
　第２端子部分５２ｂは、板状端子５０ｂを構成する導電金属板の折り畳み部である。第２端子部分５２ｂは、例えば、均一な厚さを有する導電金属板を一回以上折り畳むことによって形成されている。第２端子部分５２ｂは、均一な厚さを有する導電金属板を二回以上折り畳むことによって形成されてもよい。 The second terminal portion 52b is a folded portion of the conductive metal plate constituting the plate-shaped terminal 50b. The second terminal portion 52b is formed, for example, by folding a conductive metal plate having a uniform thickness one or more times. The second terminal portion 52b may be formed by folding a conductive metal plate having a uniform thickness two or more times.
　本実施の形態のパワー半導体装置１ｂの製造方法は、実施の形態１のパワー半導体装置１の製造方法と同様の工程を備えているが、板状端子５０ｂの製造工程の点で異なる。本実施の形態では、板状端子５０ｂは、例えば、以下の工程によって得られる。均一の厚さを有する導電金属板を準備する。導電金属板をプレス加工して、第１端子部分５１、第２端子部分５２ｂ及び第３端子部分５３を含む板状端子５０ｂが得られる。第２端子部分５２ｂは、導電金属板を一回以上折り畳むことによって形成される。 The manufacturing method of the power semiconductor device 1b of the present embodiment includes the same steps as the manufacturing method of the power semiconductor device 1 of the first embodiment, but differs in the manufacturing process of the plate-shaped terminal 50b. In the present embodiment, the plate-shaped terminal 50b is obtained by, for example, the following steps. Prepare a conductive metal plate with a uniform thickness. The conductive metal plate is press-processed to obtain a plate-shaped terminal 50b including the first terminal portion 51, the second terminal portion 52b, and the third terminal portion 53. The second terminal portion 52b is formed by folding the conductive metal plate one or more times.
　本実施の形態のパワー半導体装置１ｂ及びその製造方法は、実施の形態１のパワー半導体装置１及びその製造方法の効果に加えて、以下の効果をさらに奏する。 The power semiconductor device 1b of the present embodiment and the manufacturing method thereof exert the following effects in addition to the effects of the power semiconductor device 1 of the first embodiment and the manufacturing method thereof.
　本実施の形態のパワー半導体装置１ｂ及びその製造方法では、第２端子部分５２ｂは、板状端子５０ｂを構成する導電金属板の折り畳み部である。板状端子５０ｂを構成する導電金属板の厚さを部分的に薄くする工程が不要になる。また、本実施の形態では、板状端子５０ｂを構成する導電金属板として、実施の形態１よりも薄い導電金属板を準備すれば足りる。そのため、板状端子５０ｂのコストが低減される。パワー半導体装置１ｂのコストが低減され得る。 In the power semiconductor device 1b of the present embodiment and the manufacturing method thereof, the second terminal portion 52b is a folded portion of a conductive metal plate constituting the plate-shaped terminal 50b. The step of partially reducing the thickness of the conductive metal plate constituting the plate-shaped terminal 50b becomes unnecessary. Further, in the present embodiment, it is sufficient to prepare a conductive metal plate thinner than that of the first embodiment as the conductive metal plate constituting the plate-shaped terminal 50b. Therefore, the cost of the plate-shaped terminal 50b is reduced. The cost of the power semiconductor device 1b can be reduced.
　実施の形態３．
　図８を参照して、実施の形態３のパワー半導体装置１ｃを説明する。本実施の形態のパワー半導体装置１ｃは、実施の形態１のパワー半導体装置１と同様の構成を備えるが、以下の点で主に異なる。 Embodiment 3.
The power semiconductor device 1c of the third embodiment will be described with reference to FIG. The power semiconductor device 1c of the present embodiment has the same configuration as the power semiconductor device 1 of the first embodiment, but is mainly different in the following points.
　パワー半導体装置１ｃでは、第３端子部分５３にばね部５４が設けられている。ばね部５４は、板状端子５０ｃを構成する導電金属板を折り曲げることによって形成されている。ばね部５４は、例えば、導電金属板をプレス加工することによって得られる。 In the power semiconductor device 1c, a spring portion 54 is provided at the third terminal portion 53. The spring portion 54 is formed by bending a conductive metal plate constituting the plate-shaped terminal 50c. The spring portion 54 is obtained, for example, by pressing a conductive metal plate.
　本実施の形態のパワー半導体装置１ｃの製造方法は、実施の形態１のパワー半導体装置１の製造方法と同様の工程を備えているが、主に以下の二つの点で異なる。 The manufacturing method of the power semiconductor device 1c of the present embodiment includes the same steps as the manufacturing method of the power semiconductor device 1 of the first embodiment, but is mainly different in the following two points.
　第一に、板状端子５０ｃは、以下の工程によって得られる。均一の厚さを有する導電金属板を準備する。導電金属板をプレス加工して、第１端子部分５１、第２端子部分５２及び第３端子部分５３を含む板状端子５０ｃが得られる。第３端子部分５３に、ばね部５４が形成されている。ばね部５４は、導電金属板を折り曲げることによって形成される。 First, the plate-shaped terminal 50c is obtained by the following steps. Prepare a conductive metal plate with a uniform thickness. The conductive metal plate is press-processed to obtain a plate-shaped terminal 50c including the first terminal portion 51, the second terminal portion 52, and the third terminal portion 53. A spring portion 54 is formed in the third terminal portion 53. The spring portion 54 is formed by bending a conductive metal plate.
　第二に、板状端子５０ｃを、第１パワー半導体素子２０、第２パワー半導体素子２５及び引き出し配線４１に接合する（Ｓ４）際に、板状端子５０ｃが第１おもて面電極２１、第２おもて面電極２６及び引き出し配線４１に対して傾くことがより確実に防止される。 Second, when the plate-shaped terminal 50c is joined to the first power semiconductor element 20, the second power semiconductor element 25, and the lead-out wiring 41 (S4), the plate-shaped terminal 50c is connected to the first front surface electrode 21, Tilt with respect to the second front surface electrode 26 and the lead-out wiring 41 is more reliably prevented.
　第１端子部分５１は、第２端子部分５２よりも薄い。そのため、板状端子５０ｃの重心の位置は、第２端子部分５２に近位しており、かつ、第１端子部分５１から遠位している。すなわち、板状端子５０ｃの重心の位置は、第２導電接合部材５７に近位しており、かつ、第１導電接合部材５５及び第３導電接合部材５６から遠位している。板状端子５０ｃを、第１パワー半導体素子２０、第２パワー半導体素子２５及び引き出し配線４１に接合する（Ｓ４）際に、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６を加熱して、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６が液相になる。第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６は液相であるとき、板状端子５０ｃの重さのために、第１導電接合部材５５の厚さ、第２導電接合部材５７の厚さ及び第３導電接合部材５６の厚さは変化し得る。 The first terminal portion 51 is thinner than the second terminal portion 52. Therefore, the position of the center of gravity of the plate-shaped terminal 50c is proximal to the second terminal portion 52 and distal to the first terminal portion 51. That is, the position of the center of gravity of the plate-shaped terminal 50c is proximal to the second conductive joining member 57 and distal to the first conductive joining member 55 and the third conductive joining member 56. When the plate-shaped terminal 50c is joined to the first power semiconductor element 20, the second power semiconductor element 25, and the lead-out wiring 41 (S4), the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining are joined. By heating the member 56, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 become a liquid phase. When the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are in a liquid phase, the thickness of the first conductive joining member 55, the second, due to the weight of the plate-shaped terminal 50c. The thickness of the conductive bonding member 57 and the thickness of the third conductive bonding member 56 can be changed.
　具体的には、板状端子５０ｃの重心に近位する第２導電接合部の厚さが減少する一方で、板状端子５０ｃの重心から遠位する第１導電接合部の厚さと、板状端子５０ｃの重心から遠位する第３導電接合部の厚さとが増加することがある。板状端子５０ｃは、第１おもて面電極２１、第２おもて面電極２６及び引き出し配線４１に対して傾くことがある。 Specifically, while the thickness of the second conductive joint portion proximal to the center of gravity of the plate-shaped terminal 50c decreases, the thickness of the first conductive joint portion distal to the center of gravity of the plate-shaped terminal 50c and the plate shape. The thickness of the third conductive joint distal to the center of gravity of the terminal 50c may increase. The plate-shaped terminal 50c may be tilted with respect to the first front surface electrode 21, the second front surface electrode 26, and the lead-out wiring 41.
　すると、第１導電接合部材５５及び第３導電接合部材５６が第１パワー半導体素子２０の厚さ方向（第３方向（ｚ方向））に伸びて、第１導電接合部材５５の断面積と第３導電接合部材５６の断面積とが減少する。第１導電接合部材５５及び第３導電接合部材５６を冷却した後の第１導電接合部材５５の接合強度と第３導電接合部材５６の接合強度が不十分となることがある。また、第２導電接合部材５７を冷却した後の第２導電接合部材５７の厚さが著しく薄くなって、板状端子５０ｃから第２導電接合部材５７に大きな機械的歪みが印加されることがある。 Then, the first conductive joining member 55 and the third conductive joining member 56 extend in the thickness direction (third direction (z direction)) of the first power semiconductor element 20, and the cross-sectional area of the first conductive joining member 55 and the first 3 The cross-sectional area of the conductive joining member 56 is reduced. The joining strength of the first conductive joining member 55 and the joining strength of the third conductive joining member 56 after cooling the first conductive joining member 55 and the third conductive joining member 56 may be insufficient. Further, the thickness of the second conductive joint member 57 after cooling the second conductive joint member 57 may be remarkably reduced, and a large mechanical strain may be applied from the plate-shaped terminal 50c to the second conductive joint member 57. is there.
　しかし、第３端子部分５３に形成されたばね部５４は、第１端子部分５１と第２端子部分５２とが互いに独立に第１パワー半導体素子２０の厚さ方向（第３方向（ｚ方向））に移動することを可能にする。そのため、板状端子５０ｃの重心の位置が第２端子部分５２側に偏っていても、第１導電接合部材５５、第２導電接合部材５７及び第３導電接合部材５６が加熱されて液相になった時に、板状端子５０ｃは、第１おもて面電極２１、第２おもて面電極２６及び引き出し配線４１に対して傾くことが防止される。ばね部５４は、第１導電接合部材５５の断面積と第３導電接合部材５６の断面積とが減少して、第１導電接合部材５５の接合強度と第３導電接合部材５６の接合強度とが低下することを、確実に防止することができる。ばね部５４は、第２導電接合部材５７に大きな機械的歪みが印加されることを確実に防止することができる。 However, in the spring portion 54 formed in the third terminal portion 53, the first terminal portion 51 and the second terminal portion 52 are independent of each other in the thickness direction of the first power semiconductor element 20 (third direction (z direction)). Allows you to move to. Therefore, even if the position of the center of gravity of the plate-shaped terminal 50c is biased toward the second terminal portion 52, the first conductive joining member 55, the second conductive joining member 57, and the third conductive joining member 56 are heated to become a liquid phase. At this time, the plate-shaped terminal 50c is prevented from being tilted with respect to the first front surface electrode 21, the second front surface electrode 26, and the lead-out wiring 41. In the spring portion 54, the cross-sectional area of the first conductive joining member 55 and the cross-sectional area of the third conductive joining member 56 are reduced, so that the joining strength of the first conductive joining member 55 and the joining strength of the third conductive joining member 56 are increased. Can be reliably prevented from decreasing. The spring portion 54 can surely prevent a large mechanical strain from being applied to the second conductive joint member 57.
　本実施の形態のパワー半導体装置１ｃ及びその製造方法は、実施の形態１のパワー半導体装置１及びその製造方法と同様の効果を奏するが、以下の点で主に異なる。 The power semiconductor device 1c of the present embodiment and the manufacturing method thereof have the same effects as the power semiconductor device 1 of the first embodiment and the manufacturing method thereof, but are mainly different in the following points.
　本実施の形態のパワー半導体装置及びその製造方法では、第３端子部分５３に、板状端子５０ｃを構成する導電金属板を折り曲げることによって形成されているばね部５４が設けられている。 In the power semiconductor device and its manufacturing method of the present embodiment, the third terminal portion 53 is provided with a spring portion 54 formed by bending a conductive metal plate constituting the plate-shaped terminal 50c.
　ばね部５４は、第１導電接合部材５５の断面積と第３導電接合部材５６の断面積とが減少して、第１導電接合部材５５の接合強度と第３導電接合部材５６の接合強度とが低下することを確実に防止することができる。ばね部５４は、第２導電接合部材５７に大きな機械的歪みが印加されることを確実に防止することができる。パワー半導体装置１ｃの信頼性が向上され得る。 In the spring portion 54, the cross-sectional area of the first conductive joining member 55 and the cross-sectional area of the third conductive joining member 56 are reduced, so that the joining strength of the first conductive joining member 55 and the joining strength of the third conductive joining member 56 are increased. Can be reliably prevented from decreasing. The spring portion 54 can surely prevent a large mechanical strain from being applied to the second conductive joint member 57. The reliability of the power semiconductor device 1c can be improved.
　今回開示された実施の形態１－３はすべての点で例示であって制限的なものではないと考えられるべきである。矛盾のない限り、今回開示された実施の形態１－３の少なくとも２つを組み合わせてもよい。本開示の範囲は、上記した説明ではなく請求の範囲によって示され、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が含まれることを意図される。 It should be considered that the embodiment 1-3 disclosed this time is an example in all respects and is not restrictive. As long as there is no contradiction, at least two of Embodiments 1-3 disclosed this time may be combined. The scope of the present disclosure is indicated by the scope of claims rather than the above description, and is intended to include all modifications within the meaning and scope of the claims.
　１，１ｂ，１ｃ　パワー半導体装置、１０　基板、１０ａ　主面、１１　絶縁層、１２　おもて面導体層、１３　裏面導体層、１４　接合部材、２０　第１パワー半導体素子、２１　第１おもて面電極、２２　第１裏面電極、２３，２８　導電接合部材、２５　第２パワー半導体素子、２６　第２おもて面電極、２７　第２裏面電極、３０　ヒートシンク、３１　天板、３２　放熱フィン、３３　ジャケット、３４　入口、３５　出口、３６　流路、３７　冷媒、４０　端子台、４１，４１ｇ　引き出し配線、５０，５０ｂ，５０ｃ，５０ｇ　板状端子、５１　第１端子部分、５２，５２ｂ　第２端子部分、５３　第３端子部分、５４　ばね部、５５　第１導電接合部材、５６　第３導電接合部材、５７　第２導電接合部材、６０　第１加熱装置、６０ｂ　第２加熱装置、６１，６１ｂ　第１熱源、６２，６２ｂ　第２熱源、６３，６３ｂ　第１温度センサ、６４，６４ｂ　第２温度センサ、６５　制御部。 1,1b, 1c power semiconductor device, 10 substrate, 10a main surface, 11 insulating layer, 12 front surface conductor layer, 13 back surface conductor layer, 14 bonding member, 20 first power semiconductor element, 21 first front surface Surface electrode, 22 1st back surface electrode, 23, 28 conductive bonding member, 25 2nd power semiconductor element, 26 2nd front surface electrode, 27 2nd back surface electrode, 30 heat sink, 31 top plate, 32 heat dissipation fin, 33 Jacket, 34 inlet, 35 outlet, 36 flow path, 37 refrigerant, 40 terminal block, 41,41 g lead-out wiring, 50, 50b, 50c, 50 g plate-shaped terminal, 51 first terminal part, 52, 52b second terminal part, 53 3rd terminal part, 54 spring part, 55 1st conductive joining member, 56 3rd conductive joining member, 57 2nd conductive joining member, 60 1st heating device, 60b 2nd heating device, 61, 61b 1st heat source, 62, 62b second heat source, 63, 63b first temperature sensor, 64, 64b second temperature sensor, 65 control unit.

Claims (15)

  1. 　基板と、
    　前記基板に接合されている第１裏面電極と、前記第１裏面電極とは反対側の第１おもて面電極とを含む第１パワー半導体素子と、
    　引き出し配線と、
    　第１端子部分と、第２端子部分とを含む板状端子とを備えるパワー半導体装置であって、
    　前記第１端子部分は、第１導電接合部材を用いて前記第１おもて面電極に接合されており、
    　前記第２端子部分は、第２導電接合部材を用いて前記引き出し配線に接合されており、
    　前記第１パワー半導体素子と前記第１端子部分との間の第１の線膨張係数差は、前記引き出し配線と前記第２端子部分との間の第２の線膨張係数差よりも大きく、
    　前記第１端子部分は、前記第２端子部分よりも薄い、パワー半導体装置。     With the board
    A first power semiconductor device including a first back surface electrode bonded to the substrate and a first front surface electrode opposite to the first back surface electrode.
    Drawer wiring and
    A power semiconductor device including a plate-shaped terminal including a first terminal portion and a second terminal portion.
    The first terminal portion is bonded to the first front surface electrode by using a first conductive bonding member.
    The second terminal portion is joined to the lead-out wiring by using a second conductive joining member.
    The first linear expansion coefficient difference between the first power semiconductor element and the first terminal portion is larger than the second linear expansion coefficient difference between the lead-out wiring and the second terminal portion.
    The first terminal portion is a power semiconductor device thinner than the second terminal portion.
  2. 　前記第２端子部分の第２厚さに対する前記第１端子部分の第１厚さの比は、０．１０以上０．７５以下である、請求項１に記載のパワー半導体装置。 The power semiconductor device according to claim 1, wherein the ratio of the first thickness of the first terminal portion to the second thickness of the second terminal portion is 0.10 or more and 0.75 or less.
  3. 　前記第１端子部分の第１厚さは、０．１５ｍｍ以上０．６０ｍｍ以下であり、
    　前記第２端子部分の第２厚さは、０．８０ｍｍ以上１．５０ｍｍ以下である、請求項１に記載のパワー半導体装置。     The first thickness of the first terminal portion is 0.15 mm or more and 0.60 mm or less.
    The power semiconductor device according to claim 1, wherein the second thickness of the second terminal portion is 0.80 mm or more and 1.50 mm or less.
  4. 　前記第１導電接合部材は、金属微粒子焼結体で形成されている、請求項１から請求項３のいずれか一項に記載のパワー半導体装置。 The power semiconductor device according to any one of claims 1 to 3, wherein the first conductive bonding member is made of a metal fine particle sintered body.
  5. 　前記第１導電接合部材は、Ｓｎを主成分として含む第１はんだであり、前記第１はんだはＳｎよりも高い０．２％耐力を有しており、
    　前記第２導電接合部材は、Ｓｎを主成分として含む第２はんだであり、前記第２はんだはＳｎよりも高い熱伝導率を有している、請求項１から請求項３のいずれか一項に記載のパワー半導体装置。     The first conductive bonding member is a first solder containing Sn as a main component, and the first solder has a 0.2% proof stress higher than that of Sn.
    The second conductive bonding member is a second solder containing Sn as a main component, and the second solder has a higher thermal conductivity than Sn, any one of claims 1 to 3. The power semiconductor device described in 1.
  6. 　前記第１はんだは、Ｓｎ－Ｃｕ系はんだ、または、Ｓｎ－Ｓｂ系はんだであり、
    　前記第２はんだは、Ｓｎ－Ａｕ系はんだ、または、Ｓｎ－Ａｇ系はんだである、請求項５に記載のパワー半導体装置。     The first solder is Sn—Cu-based solder or Sn—Sb-based solder.
    The power semiconductor device according to claim 5, wherein the second solder is a Sn—Au-based solder or a Sn—Ag-based solder.
  7. 　前記板状端子は、前記第１端子部分と前記第２端子部分とを接続する第３端子部分をさらに含み、
    　前記第３端子部分は、前記第１裏面電極と前記第１おもて面電極とが互いに離間している前記第１パワー半導体素子の厚さ方向に沿って延在している、請求項１から請求項６のいずれか一項に記載のパワー半導体装置。     The plate-shaped terminal further includes a third terminal portion that connects the first terminal portion and the second terminal portion.
    The third terminal portion extends along the thickness direction of the first power semiconductor element in which the first back surface electrode and the first front surface electrode are separated from each other. The power semiconductor device according to any one of claims 6.
  8. 　前記第３端子部分に、前記板状端子を構成する導電金属板を折り曲げることによって形成されているばね部が設けられている、請求項７に記載のパワー半導体装置。 The power semiconductor device according to claim 7, wherein a spring portion formed by bending a conductive metal plate constituting the plate-shaped terminal is provided at the third terminal portion.
  9. 　前記第２端子部分は、前記板状端子を構成する導電金属板の折り畳み部である、請求項１から請求項７のいずれか一項に記載のパワー半導体装置。 The power semiconductor device according to any one of claims 1 to 7, wherein the second terminal portion is a folded portion of a conductive metal plate constituting the plate-shaped terminal.
  10. 　絶縁樹脂製の端子台をさらに備え、
    　前記引き出し配線の一部は前記端子台に埋め込まれており、
    　前記第２端子部分は、前記第２導電接合部材を用いて、前記端子台から露出している前記引き出し配線の部分に接合されており、
    　前記端子台の熱伝導率は、前記引き出し配線の熱伝導率よりも小さく、かつ、前記板状端子の熱伝導率よりも小さい、請求項１から請求項９のいずれか一項に記載のパワー半導体装置。     With an additional terminal block made of insulating resin,
    A part of the lead-out wiring is embedded in the terminal block.
    The second terminal portion is joined to the portion of the lead-out wiring exposed from the terminal block by using the second conductive joining member.
    The power according to any one of claims 1 to 9, wherein the thermal conductivity of the terminal block is smaller than the thermal conductivity of the lead-out wiring and smaller than the thermal conductivity of the plate-shaped terminal. Semiconductor device.
  11. 　前記基板に接合されている第２裏面電極と、前記第２裏面電極とは反対側の第２おもて面電極とを含む第２パワー半導体素子をさらに備え、
    　前記第１端子部分は、第３導電接合部材を用いて前記第２おもて面電極に接合されており、
    　前記第２パワー半導体素子と前記第１端子部分との間の第３の線膨張係数差は、前記引き出し配線と前記第２端子部分との間の前記第２の線膨張係数差よりも大きい、請求項１から請求項１０のいずれか一項に記載のパワー半導体装置。     A second power semiconductor element including a second back surface electrode bonded to the substrate and a second front surface electrode opposite to the second back surface electrode is further provided.
    The first terminal portion is bonded to the second front surface electrode by using a third conductive bonding member.
    The third linear expansion coefficient difference between the second power semiconductor element and the first terminal portion is larger than the second linear expansion coefficient difference between the lead-out wiring and the second terminal portion. The power semiconductor device according to any one of claims 1 to 10.
  12. 　第１パワー半導体素子の第１裏面電極を基板に接合することと、
    　板状端子を、前記第１裏面電極とは反対側の前記第１パワー半導体素子の第１おもて面電極と引き出し配線とに接合することとを備え、
    　前記板状端子は、第１端子部分と、第２端子部分とを含み、
    　前記第１パワー半導体素子と前記第１端子部分との間の第１の線膨張係数の差は、前記引き出し配線と前記第２端子部分との間の第２の線膨張係数の差よりも大きく、
    　前記第１端子部分は、前記第２端子部分よりも薄く、
    　前記第１端子部分が第１導電接合部材を用いて前記第１おもて面電極に接合されながら、前記第２端子部分は第２導電接合部材を用いて前記引き出し配線に接合され、
    　前記第１端子部分を前記第１おもて面電極に接合する際、前記第１導電接合部材は第１熱源を用いて加熱され、前記第１熱源は、第１温度センサを用いて測定される前記第１端子部分の第１温度に基づいて制御され、
    　前記第２端子部分を前記引き出し配線に接合する際、前記第２導電接合部材は第２熱源を用いて加熱され、前記第２熱源は、第２温度センサを用いて測定される前記第２端子部分の第２温度に基づいて制御される、パワー半導体装置の製造方法。     Bonding the first back electrode of the first power semiconductor element to the substrate and
    The plate-shaped terminal is provided by joining the first front surface electrode and the lead-out wiring of the first power semiconductor element on the side opposite to the first back surface electrode.
    The plate-shaped terminal includes a first terminal portion and a second terminal portion.
    The difference in the first linear expansion coefficient between the first power semiconductor element and the first terminal portion is larger than the difference in the second linear expansion coefficient between the lead-out wiring and the second terminal portion. ,
    The first terminal portion is thinner than the second terminal portion,
    While the first terminal portion is bonded to the first front surface electrode using the first conductive bonding member, the second terminal portion is bonded to the lead-out wiring using the second conductive bonding member.
    When the first terminal portion is joined to the first front surface electrode, the first conductive bonding member is heated by using a first heat source, and the first heat source is measured by using a first temperature sensor. It is controlled based on the first temperature of the first terminal portion.
    When the second terminal portion is joined to the lead-out wiring, the second conductive joining member is heated by using a second heat source, and the second heat source is measured by using a second temperature sensor. A method of manufacturing a power semiconductor device, which is controlled based on the second temperature of a portion.
  13. 　前記第１導電接合部材は、Ｓｎを主成分として含む第１はんだであり、前記第１はんだはＳｎよりも高い０．２％耐力を有しており、
    　前記第２導電接合部材は、Ｓｎを主成分として含む第２はんだであり、前記第２はんだはＳｎよりも高い熱伝導率を有している、請求項１２に記載のパワー半導体装置の製造方法。     The first conductive bonding member is a first solder containing Sn as a main component, and the first solder has a 0.2% proof stress higher than that of Sn.
    The method for manufacturing a power semiconductor device according to claim 12, wherein the second conductive bonding member is a second solder containing Sn as a main component, and the second solder has a higher thermal conductivity than Sn. ..
  14. 　前記第１はんだは、Ｓｎ－Ｃｕ系はんだ、または、Ｓｎ－Ｓｂ系はんだであり、
    　前記第２はんだは、Ｓｎ－Ａｕ系はんだ、または、Ｓｎ－Ａｇ系はんだである、請求項１３に記載のパワー半導体装置の製造方法。     The first solder is Sn—Cu-based solder or Sn—Sb-based solder.
    The method for manufacturing a power semiconductor device according to claim 13, wherein the second solder is a Sn—Au-based solder or a Sn—Ag-based solder.
  15. 　前記板状端子は、前記第１端子部分と前記第２端子部分とを接続する第３端子部分をさらに含み、
    　前記第３端子部分は、前記第１裏面電極と前記第１おもて面電極とが互いに離間している前記第１パワー半導体素子の厚さ方向に沿って延在しており、
    　前記第３端子部分に、前記板状端子を構成する導電金属板を折り曲げることによって形成されているばね部が設けられている、請求項１２から請求項１４のいずれか一項に記載のパワー半導体装置の製造方法。     The plate-shaped terminal further includes a third terminal portion that connects the first terminal portion and the second terminal portion.
    The third terminal portion extends along the thickness direction of the first power semiconductor element in which the first back surface electrode and the first front surface electrode are separated from each other.
    The power semiconductor according to any one of claims 12 to 14, wherein a spring portion formed by bending a conductive metal plate constituting the plate-shaped terminal is provided in the third terminal portion. How to manufacture the device.
PCT/JP2020/042392 2019-12-02 2020-11-13 Power semiconductor device, and method for manufacturing same WO2021111846A1 (en)

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JP2006253516A (en) * 2005-03-14 2006-09-21 Hitachi Ltd Power semiconductor device
JP2008041851A (en) * 2006-08-04 2008-02-21 Hitachi Ltd Power semiconductor device
WO2017221730A1 (en) * 2016-06-24 2017-12-28 三菱電機株式会社 Power semiconductor device and method for manufacturing power semiconductor device
JP2019186264A (en) * 2018-04-02 2019-10-24 富士電機株式会社 Assembly jig and manufacturing method of semiconductor device
JP2019197842A (en) * 2018-05-11 2019-11-14 三菱電機株式会社 Power module, electric power conversion system, and method of manufacturing power module

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006253516A (en) * 2005-03-14 2006-09-21 Hitachi Ltd Power semiconductor device
JP2008041851A (en) * 2006-08-04 2008-02-21 Hitachi Ltd Power semiconductor device
WO2017221730A1 (en) * 2016-06-24 2017-12-28 三菱電機株式会社 Power semiconductor device and method for manufacturing power semiconductor device
JP2019186264A (en) * 2018-04-02 2019-10-24 富士電機株式会社 Assembly jig and manufacturing method of semiconductor device
JP2019197842A (en) * 2018-05-11 2019-11-14 三菱電機株式会社 Power module, electric power conversion system, and method of manufacturing power module

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