WO2018135221A1 - 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
WO2018135221A1
WO2018135221A1 PCT/JP2017/045675 JP2017045675W WO2018135221A1 WO 2018135221 A1 WO2018135221 A1 WO 2018135221A1 JP 2017045675 W JP2017045675 W JP 2017045675W WO 2018135221 A1 WO2018135221 A1 WO 2018135221A1
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WO
WIPO (PCT)
Prior art keywords
insulating sheet
power semiconductor
circuit body
semiconductor device
cooling body
Prior art date
Application number
PCT/JP2017/045675
Other languages
French (fr)
Japanese (ja)
Inventor
順平 楠川
円丈 露野
健 徳山
晃 松下
佐藤　俊也
Original Assignee
日立オートモティブシステムズ株式会社
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Publication of WO2018135221A1 publication Critical patent/WO2018135221A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L25/00—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof
    • H01L25/03—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes
    • H01L25/04—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers
    • H01L25/07—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof all the devices being of a type provided for in the same subgroup of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. assemblies of rectifier diodes the devices not having separate containers the devices being of a type provided for in group H01L29/00
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L25/00—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof
    • H01L25/18—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof the devices being of types provided for in two or more different subgroups of the same main group of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2224/00—Indexing scheme for arrangements for connecting or disconnecting semiconductor or solid-state bodies and methods related thereto as covered by H01L24/00
    • H01L2224/01—Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
    • H01L2224/26—Layer connectors, e.g. plate connectors, solder or adhesive layers; Manufacturing methods related thereto
    • H01L2224/31—Structure, shape, material or disposition of the layer connectors after the connecting process
    • H01L2224/33—Structure, shape, material or disposition of the layer connectors after the connecting process of a plurality of layer connectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • 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
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/4805—Shape
    • H01L2224/4809—Loop shape
    • H01L2224/48091—Arched
    • 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
    • H01L2224/42—Wire connectors; Manufacturing methods related thereto
    • H01L2224/47—Structure, shape, material or disposition of the wire connectors after the connecting process
    • H01L2224/48—Structure, shape, material or disposition of the wire connectors after the connecting process of an individual wire connector
    • H01L2224/481—Disposition
    • H01L2224/48151—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
    • H01L2224/48221—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
    • H01L2224/48245—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 metallic
    • H01L2224/48247—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 metallic connecting the wire to a bond pad of the item
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/15—Details of package parts other than the semiconductor or other solid state devices to be connected
    • H01L2924/181—Encapsulation

Definitions

  • the present invention relates to a power semiconductor device and a manufacturing method thereof, and more particularly, to a power semiconductor device used in an in-vehicle power conversion device and a manufacturing method thereof.
  • EV electric vehicle
  • HEV hybrid car
  • a pseudo AC voltage is created by switching the DC voltage of the battery and the power semiconductor element, and the motor can be driven with high efficiency.
  • this power semiconductor element Since this power semiconductor element generates heat when energized, high heat dissipation is required.
  • a metal cooling body having fins is used for heat radiation, and grounded to ground (GND) for the purpose of stabilizing the potential and preventing electric shock.
  • GND ground
  • an insulating member is required between the power semiconductor element and the cooling body, and the insulating member is required to have excellent thermal conductivity and high insulation reliability.
  • an insulating layer is disposed between a circuit body incorporating a semiconductor element and the heat radiating body, and heat generated by the semiconductor element is radiated through the insulating layer.
  • the power semiconductor device described in Patent Document 1 has an insulating sheet disposed between a circuit body incorporating a power semiconductor element and a cooling body, thereby providing thermal conductivity and insulation between the power semiconductor element and the cooling body. Have. Moreover, the separation of the cooling body and the circuit body is suppressed by devising the structure of the metal case member including the cooling body.
  • an object of the present invention is to improve the adhesion and adhesion between the insulating sheet and the covering material, suppress the separation between the insulating sheet and the covering material, and improve the insulation reliability.
  • a circuit body having a power semiconductor element, a cooling body facing the circuit body, and a space between the circuit body and the cooling body are arranged.
  • the insulation reliability of the power semiconductor device can be improved.
  • FIG. 3 is an enlarged cross-sectional view showing a state where an insulating sheet 110A is peeled off from a cooling body 108A and a state where an insulating sheet 108B is peeled off from a circuit body 150 in FIG.
  • FIG. 3 is an internal plan view focusing on portions of an insulating sheet 110A and an insulating sheet 110B of the power semiconductor device 100.
  • FIG. 5 is an enlarged cross-sectional view of a portion B of the power semiconductor device 100 of the present example of FIG. 4.
  • 2 is a cross-sectional structure diagram of a circuit body 150 of a power semiconductor device 100.
  • FIG. It is a figure which shows the result of having implemented the temperature cycle test with respect to the Example and the comparative example, and measuring the partial discharge start voltage of the power semiconductor device for every predetermined cycle.
  • FIG. 1 is a cross-sectional structure diagram of a power semiconductor device 100 as a comparative example.
  • FIG. 2 is an enlarged cross-sectional view of a dotted-line square portion in FIG. 3 is an enlarged cross-sectional view illustrating a state where the insulating sheet 110A is peeled from the cooling body 108A and a state where the insulating sheet 110B is peeled from the circuit body 150 in FIG.
  • the insulating sheet 110A and the insulating sheet 110B are disposed between the circuit body 150, the cooling body 108A, and the cooling body 108B.
  • the insulating sheet 110A and the circuit body 150 are substantially equal, or the insulating sheet 110A has a side formed larger than the circuit body 150. It was.
  • a coating material (for example, potting resin) is formed on the outer surface of the insulating sheet 110A that is perpendicular to the contact surface of the insulating sheet 110A with the circuit body 150 and the contact surface of the insulating sheet 110A with the cooling body 108A.
  • the outer shape of the insulating sheet 110A is cut from an insulating sheet having a size larger than that required for the power semiconductor device 100 to an insulating sheet having a size necessary for the power semiconductor device, the outer shape of the insulating sheet is In general, it has a straight shape with no irregularities.
  • the separation is caused by the insulation sheets 110A and 110B and the circuit body 150, and the insulating sheets 110A and 110B and the cooling bodies 108A and 108B. There is a possibility of spreading to the separation (121 and 122 in FIG. 3).
  • the insulating sheets 110A and 110B are formed to be thin in order to improve heat dissipation. However, the insulating sheets 110A and 110B play a role of insulation between the circuit body 150 and the cooling bodies 108A and 108B, and the insulation sheets 110A and 110B and the circuit body 150 are insulated. When the sheets 110A and 110B are separated from the cooling bodies 108A and 108B, partial discharge may be generated in the separated spaces.
  • the insulating sheets 110A and 110B when viewed from the direction perpendicular to the contact surface between the circuit body 150 and the insulating sheets 110A and 110B, the insulating sheets 110A and 110B have sides formed smaller than the circuit body 150 and the cooling bodies 108A and 108B. And the sides of the insulating sheets 110 ⁇ / b> A and 110 ⁇ / b> B are formed in a concavo-convex shape so that the covering material 111 is bitten.
  • FIG. 4 is a cross-sectional structure diagram of the power semiconductor device 100 of the present embodiment.
  • FIG. 5 is an internal plan view focusing on the insulating sheet 110 ⁇ / b> A and the insulating sheet 110 ⁇ / b> B of the power semiconductor device 100.
  • FIG. 6 is a diagram for explaining a mechanism for forming a concavo-convex shape on the outer shape of the insulating sheet 110A and the insulating sheet 110B, and shows a state before the insulating sheet 110A and the insulating sheet 110B are pressed.
  • FIG. 5 is an internal plan view focusing on the insulating sheet 110 ⁇ / b> A and the insulating sheet 110 ⁇ / b> B of the power semiconductor device 100.
  • FIG. 6 is a diagram for explaining a mechanism for forming a concavo-convex shape on the outer shape of the insulating sheet 110A and the insulating sheet 110B, and shows a state before the insulating sheet 110A and the
  • FIG. 7 is a diagram for explaining a mechanism for forming a concavo-convex pattern on the outer shape of the insulating sheet 110A and the insulating sheet 110B, and shows a state after the insulating sheet 110A and the insulating sheet 110B are pressed.
  • FIG. 8 is an enlarged cross-sectional view of part B of the power semiconductor device 100 of this embodiment shown in FIG.
  • FIG. 9 is a cross-sectional structure diagram of the circuit body 150 of the power semiconductor device 100.
  • the power semiconductor element 101 is fixed to the conductor plate 102A and the conductor plate 102B via the bonding material 103A and the bonding material 103B.
  • the conductor plate 102A and the conductor plate 102B are made of, for example, copper, copper alloy, aluminum, aluminum alloy, or the like.
  • Solder is mainly used for the bonding material 103A and the bonding material 103B, but a conductive paste in which metal powder such as silver is dispersed in resin is also used.
  • IGBTs and diodes as the power semiconductor element 101, and Si devices are mainly used at present, but devices such as SiC can be used.
  • the power semiconductor element 101, the conductor plate 102A, and the conductor plate 102B are sealed by a technique such as transfer molding using the sealing resin 106, and the circuit body 150 is completed.
  • the sealing resin 106 a resin mainly composed of an epoxy resin is usually used.
  • fillers such as silica and alumina are dispersed in the resin to adjust the thermal expansion coefficient. Is used.
  • a part of the input / output terminal 104 protrudes from the sealing resin 106.
  • the case 109 includes a cooling body 108 ⁇ / b> A and a cooling body 108 ⁇ / b> B in which heat dissipating fins 107 are formed on the outer periphery, a side wall portion, and a seal portion that forms an insertion port for inserting the circuit body 150.
  • the circuit body 150 is inserted in a state where the insulating sheet 110A and the insulating sheet 110B are disposed on both surfaces of the surface of the circuit body 150 where the conductor plate 102A and the conductor plate 102B are exposed.
  • the arrangement relationship between the cooling body 108A, the cooling body 108B, the insulating sheet 110A, the insulating sheet 110B, and the circuit body 150 will be described.
  • the insulating sheet 110A and the insulating sheet 110B are more than the circuit body 150, the cooling body 108A, and the cooling body 108B. Try to have small sides.
  • the outermost broken lines 108A 'and 108B' indicate the outer peripheral shapes of the cooling bodies 108A and 108B.
  • a solid line 150A indicates the outer peripheral shape of the contact surface of the circuit body 150 with the insulating sheet 110A or the insulating sheet 110B.
  • the inner peripheral broken lines 110A 'and 110B' indicate the outer peripheral shape of the insulating sheet 110A or the insulating sheet 110B before being pressed by the press. Further, the dotted line on the innermost peripheral side shows a state in which the conductor plates 102A and 102B are exposed from the sealing resin 106.
  • the outer shapes 110A 'and 110B' of the insulating sheet are formed to be smaller than the contact surface 150A between the inner wall surface shapes 108A 'and 108B' of the cooling body and the insulating sheet of the circuit body 150.
  • outer peripheral shape 110A ′ of the insulating sheet 110A before being pressed by the press and the outer peripheral shape 110B ′ of the insulating sheet 110B before being pressed by the press are formed to be larger than the outer shapes of the conductor plates 102A and 102B.
  • the circuit body 150, the insulating sheet 110A, and the insulating sheet 110B are arranged at the predetermined positions in the case 109, they are set in a vacuum press machine, and the radiating fin 107 side of the cooling bodies 108A and 108B is pressed at a high temperature. To do.
  • the cooling body 108A and the insulating sheet 110A between the insulating sheet 110A and the circuit body 150, between the cooling body 108B and the insulating sheet 110B, and between the insulating sheet 110B and the circuit body 150.
  • the concavo-convex shapes 110A ′′ and 110B ′′ as shown in FIG. 5 are formed on the outer shape of the insulating sheet 110A or the insulating sheet 110B.
  • FIG. 6 and 7 are schematic views of the surface of the insulating sheet 110 (insulating sheet 110A or 110B) viewed from the pressing direction of the cooling body 108A or the cooling body 108B.
  • FIG. 6 shows a state before pressing
  • FIG. 7 shows a state after pressing.
  • the lower side of the drawing shows the outer peripheral shape of the insulating sheet 110.
  • the insulating sheet 110 is composed of a resin 132 in which inorganic fillers 131 having different particle sizes are dispersedly contained.
  • the inorganic filler 131 is preferably one having good thermal conductivity in order to dissipate the heat generated by the power semiconductor element 101 to the cooling bodies 108A and 108B.
  • boron nitride (BN), aluminum nitride (AlN), aluminum oxide (Al 2 O 3 ) or the like can be used.
  • the outer peripheral shapes 110A ′ and 110B ′ of the insulating sheet 110 are formed smaller than the contact surface between the inner wall surface of the cooling body 108A or the cooling body 108B and the insulating sheet 110 of the circuit body 150, the outer peripheral shape 110A of the insulating sheet 110.
  • a force (this force is referred to as a scavenging force) is applied to the resin 132 in a state where the pressure is also applied to “and 110B” and the viscosity is lowered, in order to flow in the outer direction of the insulating sheet 110.
  • This scavenging force can be controlled by the viscosity of the resin 132 of the insulating sheet 110 and the pressing pressure. The lower the viscosity and the higher the pressure, the larger the scavenging force.
  • the resistance force acts on the inorganic filler 131 dispersed in the resin 132 against the scavenging force, and this resistance force is proportional to the particle size and weight of the filler 131, and the resistance force increases as the inorganic filler 131 increases.
  • the force obtained by subtracting the resistance force from the scavenging force becomes the force through which the resin 132 flows in the outer direction of the insulating sheet 110.
  • FIG. 7 shows the state of the insulating sheet 110 after being pressed.
  • the portion where the resin 132 and the small inorganic filler 131 are distributed is pushed out in the outer direction, and the portion where the large inorganic filler 131 is distributed is not pushed out.
  • an uneven shape is formed in the outer shape of the insulating sheet 110. Can be made.
  • the insulating sheet 110 preferably contains a filler having a particle size of 10 ⁇ m or more.
  • the integrated circuit body 150, the insulating sheet 110, and the case 109 are taken out from the press machine, and the opening portion on the terminal side of the case 109 is taken out. Then, a covering material 111 (potting resin) is poured into the interior space of the case 109 to fill and form the covering material 111.
  • potting resin potting resin
  • FIG. 9 is a cross-sectional view of part B of the power semiconductor device of this embodiment shown in FIG. As shown in FIG. 8, the covering material 111 is formed so as to be bitten into the outer shape of the insulating sheet 110 pressed with the resin 132 or the small inorganic filler 131.
  • the power semiconductor device 100 is completed by placing it in a high-temperature bath and curing the covering material 111 under predetermined conditions.
  • the separation between the outer shape of the insulating sheet 110 and the covering material 111 advances to the separation between the insulating sheet 110 and the cooling body 108A or 108B, or the separation between the insulating sheet 110 and the circuit body 150, and a high voltage is applied to the separation portion. Then, a phenomenon called partial discharge occurs.
  • FIG. 10 shows an example and a comparative example.
  • the temperature cycle test is implemented, and the result of measuring the partial discharge start voltage of the power semiconductor device every predetermined cycle is shown.
  • the horizontal axis represents the number of temperature cycles
  • the vertical axis represents the partial discharge start voltage at each temperature cycle.
  • the partial discharge start voltage decreased to 2.3 kVrms after 2000 temperature cycles.
  • the partial discharge start voltage decreased with the progress of the test cycle.
  • the decrease in the partial discharge start voltage is caused by the interface between the outer portion of the insulating sheet 110 and the covering material 111 being separated from each other, and starting from that portion, the cooling body 108A or 108B and the insulating sheet 110 are separated from each other. This is because the electric field is concentrated and partial discharge occurs.
  • the outer shape portion of the insulating sheet 110 was a linear shape, and the adhesion (adhesion) strength of the covering material was weak, and therefore separation occurred.
  • DESCRIPTION OF SYMBOLS 100 Power semiconductor device, 101 ... Power semiconductor element, 102A ... Conductor plate, 102B ... Conductor plate, 103A ... Bonding material, 103B ... Bonding material, 104 ... Input / output terminal, 104A ... AC output terminal, 104B ... DC input terminal, 104C ... Control terminal, 105 ... Metal thin wire, 106 ... Sealing resin, 107 ... Heat radiating fin, 108A ... Cooling body, 108A '... Outer peripheral shape of cooling body 108A, 108B' ... Outer peripheral shape of cooling body 108B, 108B ...

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

Abstract

The present invention addresses the problem of improving sticking force or adhesive force between an insulating sheet and a coating material, preventing separation of the insulating sheet and the coating material, and improving insulation reliability. A power semiconductor device of the present invention is provided with: a circuit body having a power semiconductor element; a cooling body opposing the circuit body; an insulating sheet which is disposed in a space between the circuit body and the cooling body and which contains an inorganic filler; and a coating material contacting the circuit body, the cooling body, and the insulating sheet. When viewed from a direction perpendicular to a contact surface between the circuit body and the insulating sheet, the insulating sheet has a side formed smaller than the circuit body and the cooling body, wherein the side of the insulating sheet is formed in an irregular shape such that the coating material can be embedded therein.

Description

パワー半導体装置及びその製造方法Power semiconductor device and manufacturing method thereof
　本発明は、パワー半導体装置及びその製造方法に関し、特に車載用電力変換装置に用いられるパワー半導体装置及びその製造方法に関する。 The present invention relates to a power semiconductor device and a manufacturing method thereof, and more particularly, to a power semiconductor device used in an in-vehicle power conversion device and a manufacturing method thereof.
　近年、地球規模での環境や資源問題がクローズアップされており、資源の有効活用、省エネルギー化の推進、地球温暖化ガスの排出を抑制するため、パワー半導体素子を用いた電力変換装置が民生用、車載用、鉄道用、産業用、インフラ用などの分野に利用されている。 In recent years, environmental and resource issues on a global scale have been highlighted, and in order to effectively use resources, promote energy conservation, and suppress global warming gas emissions, power conversion devices using power semiconductor elements are for consumer use. It is used in fields such as automotive, railway, industrial, and infrastructure.
　例えば車載用で見ると、モータで駆動する電気自動車（ＥＶ）や、モータ駆動とエンジン駆動を組み合わせたハイブリッドカー（ＨＥＶ）などがある。これらＥＶやＨＥＶでは、バッテリーの直流電圧を、パワー半導体素子をスイッチングすることにより、擬似的な交流電圧を作りだし、高効率にモータを駆動できる。 For example, when viewed in a vehicle, there are an electric vehicle (EV) driven by a motor and a hybrid car (HEV) combining motor driving and engine driving. In these EVs and HEVs, a pseudo AC voltage is created by switching the DC voltage of the battery and the power semiconductor element, and the motor can be driven with high efficiency.
　このパワー半導体素子は通電により発熱するため、高い放熱性が求められる。通常、放熱には、フィンを有する金属製の冷却体を用い、電位の安定化や、感電防止を目的としてグラウンド（ＧＮＤ）に接地する。このため、パワー半導体素子と冷却体との間には絶縁部材が必要であり、絶縁部材には優れた熱伝導性と高い絶縁信頼性が必要とされる。 Since this power semiconductor element generates heat when energized, high heat dissipation is required. Usually, a metal cooling body having fins is used for heat radiation, and grounded to ground (GND) for the purpose of stabilizing the potential and preventing electric shock. For this reason, an insulating member is required between the power semiconductor element and the cooling body, and the insulating member is required to have excellent thermal conductivity and high insulation reliability.
　放熱性を向上する手段としては、例えば特許文献１に示されるような、半導体素子を内蔵した回路体と放熱体の間に絶縁層が配置され、半導体素子の発熱を絶縁層を介して放熱体に逃がす構造のパワー半導体装置が知られている。 As a means for improving heat dissipation, for example, as disclosed in Patent Document 1, an insulating layer is disposed between a circuit body incorporating a semiconductor element and the heat radiating body, and heat generated by the semiconductor element is radiated through the insulating layer. 2. Description of the Related Art A power semiconductor device having a structure for releasing the heat is known.
　特許文献１に記載されたパワー半導体装置は、パワー半導体素子を内蔵した回路体と冷却体の間に絶縁シートを配置することで、パワー半導体素子と冷却体の間の熱伝導性と絶縁性を有している。また、冷却体を含む金属ケース部材の構造を工夫することで、冷却体と回路体との離間抑制を図っている。 The power semiconductor device described in Patent Document 1 has an insulating sheet disposed between a circuit body incorporating a power semiconductor element and a cooling body, thereby providing thermal conductivity and insulation between the power semiconductor element and the cooling body. Have. Moreover, the separation of the cooling body and the circuit body is suppressed by devising the structure of the metal case member including the cooling body.
　しかし、絶縁シートと被覆材間の離間に関しての抑制効果は不明である。絶縁シートと被覆材間が離間した場合のパワー半導体装置の絶縁信頼性に対する更なる向上が求められている。 However, the effect of suppressing the separation between the insulating sheet and the covering material is unknown. There is a demand for further improvement in the insulation reliability of the power semiconductor device when the insulating sheet and the covering material are separated from each other.
特開２０１６－３９２２４号公報JP 2016-39224 A
　そこで本発明の課題は、絶縁シートと被覆材間の密着力、接着力を向上させ、絶縁シートと被覆材との離間を抑制し、絶縁信頼性を向上させることである。 Therefore, an object of the present invention is to improve the adhesion and adhesion between the insulating sheet and the covering material, suppress the separation between the insulating sheet and the covering material, and improve the insulation reliability.
　上記課題を解決するために、本発明に係るパワー半導体装置では、パワー半導体素子を有する回路体と、前記回路体と対向する冷却体と、前記回路体と前記冷却体の間の空間に配置されかつ無機フィラーを含有する絶縁シートと、前記回路体と前記冷却体と前記絶縁シートに接する被覆材と、を備え、前記回路体と前記絶縁シートとの接触面の直角方向から見た場合、前記絶縁シートは前記回路体と前記冷却体よりも小さく形成された辺を有し、前記絶縁シートの前記辺は、前記被覆材が噛み込まれるような凹凸型に形成する。 In order to solve the above problems, in a power semiconductor device according to the present invention, a circuit body having a power semiconductor element, a cooling body facing the circuit body, and a space between the circuit body and the cooling body are arranged. And an insulating sheet containing an inorganic filler, and the circuit body, the cooling body, and a coating material in contact with the insulating sheet, and when viewed from the direction perpendicular to the contact surface between the circuit body and the insulating sheet, The insulating sheet has sides that are formed smaller than the circuit body and the cooling body, and the sides of the insulating sheet are formed in a concavo-convex shape so that the covering material is bitten.
　本発明により、パワー半導体装置の絶縁信頼性を向上させることができる。 According to the present invention, the insulation reliability of the power semiconductor device can be improved.
比較例としてのパワー半導体装置の断面構造図である。It is sectional drawing of the power semiconductor device as a comparative example. 図１の点線四角部の拡大断面図である。It is an expanded sectional view of the dotted-line square part of FIG. 図２において絶縁シート１１０Ａが冷却体１０８Ａから剥離した状態と、絶縁シート１０８Ｂが回路体１５０から剥離した状態を示す拡大断面図である。FIG. 3 is an enlarged cross-sectional view showing a state where an insulating sheet 110A is peeled off from a cooling body 108A and a state where an insulating sheet 108B is peeled off from a circuit body 150 in FIG. 本実施例のパワー半導体装置１００の断面構造図である。It is sectional structure drawing of the power semiconductor device 100 of a present Example. パワー半導体装置１００の絶縁シート１１０Ａ及び絶縁シート１１０Ｂの部分に着目した内部平面図である。3 is an internal plan view focusing on portions of an insulating sheet 110A and an insulating sheet 110B of the power semiconductor device 100. FIG. 絶縁シート１１０Ａ及び絶縁シート１１０Ｂの外形に凹凸型を形成するメカニズムを説明するための図であり、絶縁シート１１０Ａ及び絶縁シート１１０Ｂを押圧する前の状態を示す。It is a figure for demonstrating the mechanism in which an uneven | corrugated type | mold is formed in the external shape of 110 A of insulating sheets and the insulating sheet 110B, and shows the state before pressing the insulating sheet 110A and the insulating sheet 110B. 絶縁シート１１０Ａ及び絶縁シート１１０Ｂの外形に凹凸型を形成するメカニズムを説明するための図であり、絶縁シート１１０Ａ及び絶縁シート１１０Ｂを押圧した後の状態を示す。It is a figure for demonstrating the mechanism which forms an uneven | corrugated type | mold in the external shape of 110 A of insulating sheets and the insulating sheet 110B, and shows the state after pressing the insulating sheet 110A and the insulating sheet 110B. 図４の本実施例のパワー半導体装置１００のＢ部の拡大断面図である。FIG. 5 is an enlarged cross-sectional view of a portion B of the power semiconductor device 100 of the present example of FIG. 4. パワー半導体装置１００の回路体１５０の断面構造図である。2 is a cross-sectional structure diagram of a circuit body 150 of a power semiconductor device 100. FIG. 実施例及び比較例に対し、温度サイクル試験を実施し、所定サイクル毎にパワー半導体装置の部分放電開始電圧を測定した結果を示す図である。It is a figure which shows the result of having implemented the temperature cycle test with respect to the Example and the comparative example, and measuring the partial discharge start voltage of the power semiconductor device for every predetermined cycle.
　以下、本実施形態の課題及び原理を説明するために、比較例の図面を用いて説明する。図１は、比較例としてのパワー半導体装置１００の断面構造図である。図２は、図１の点線四角部の拡大断面図である。図３は、図２において絶縁シート１１０Ａが冷却体１０８Ａから剥離した状態と、絶縁シート１１０Ｂが回路体１５０から剥離した状態を示す拡大断面図である。 Hereinafter, in order to explain the problem and principle of the present embodiment, a description will be given with reference to the drawings of comparative examples. FIG. 1 is a cross-sectional structure diagram of a power semiconductor device 100 as a comparative example. FIG. 2 is an enlarged cross-sectional view of a dotted-line square portion in FIG. 3 is an enlarged cross-sectional view illustrating a state where the insulating sheet 110A is peeled from the cooling body 108A and a state where the insulating sheet 110B is peeled from the circuit body 150 in FIG.
　回路体１５０と冷却体１０８Ａ及び冷却体１０８Ｂとの間に絶縁シート１１０Ａと絶縁シート１１０Ｂが配置される。回路体１５０と絶縁シート１１０Ａとの接触面の直角方向から見た場合、絶縁シート１１０Ａと回路体１５０はほぼ等しいか、もしくは絶縁シート１１０Ａは回路体１５０よりも大きく形成された辺を有していた。 The insulating sheet 110A and the insulating sheet 110B are disposed between the circuit body 150, the cooling body 108A, and the cooling body 108B. When viewed from the direction perpendicular to the contact surface between the circuit body 150 and the insulating sheet 110A, the insulating sheet 110A and the circuit body 150 are substantially equal, or the insulating sheet 110A has a side formed larger than the circuit body 150. It was.
　絶縁シート１１０Ａの回路体１５０との接触面と、絶縁シート１１０Ａの冷却体１０８Ａとの接触面に直角方向になる絶縁シート１１０Ａの外形側面には、被覆材（例えばポッティング樹脂）が形成される。 A coating material (for example, potting resin) is formed on the outer surface of the insulating sheet 110A that is perpendicular to the contact surface of the insulating sheet 110A with the circuit body 150 and the contact surface of the insulating sheet 110A with the cooling body 108A.
　絶縁シート１１０Ａの外形は、パワー半導体装置１００に必要なサイズの絶縁シートよりもより大きなサイズの絶縁シートから、パワー半導体装置に必要なサイズの絶縁シートに切断されるため、絶縁シートの外形は、一般的に凹凸のない直線状の形状を有している。 Since the outer shape of the insulating sheet 110A is cut from an insulating sheet having a size larger than that required for the power semiconductor device 100 to an insulating sheet having a size necessary for the power semiconductor device, the outer shape of the insulating sheet is In general, it has a straight shape with no irregularities.
　このような絶縁シートの外形が略直線形状であると、絶縁シート１１０Ａ、１１０Ｂと被覆材１１１の接合する力が小さくなり、絶縁シート１１０Ａ、１１０Ｂの外形側面と被覆材１１１との間で離間（図２の１２０Ａ及び１２０Ｂ）する可能性が高くなる。 When the outer shape of such an insulating sheet is substantially linear, the bonding force between the insulating sheets 110A and 110B and the covering material 111 is reduced, and the outer side surface of the insulating sheets 110A and 110B and the covering material 111 are separated ( The possibility of 120A and 120B in FIG.
　また、絶縁シート１１０Ａ、１１０Ｂの外形側面と被覆材１１１との間で、もし離間が生じた場合、その離間が絶縁シート１１０Ａ、１１０Ｂと回路体１５０、絶縁シート１１０Ａ、１１０Ｂと冷却体１０８Ａ、１０８Ｂ間の離間（図３の１２１と１２２）に広がる可能性がある。 In addition, if separation occurs between the outer side surfaces of the insulating sheets 110A and 110B and the covering material 111, the separation is caused by the insulation sheets 110A and 110B and the circuit body 150, and the insulating sheets 110A and 110B and the cooling bodies 108A and 108B. There is a possibility of spreading to the separation (121 and 122 in FIG. 3).
　絶縁シート１１０Ａ、１１０Ｂは放熱性を高めるため薄く形成されるが、回路体１５０と冷却体１０８Ａ、１０８Ｂ間の絶縁の役割を担っており、絶縁シート１１０Ａ、１１０Ｂと回路体１５０との間、絶縁シート１１０Ａ、１１０Ｂを冷却体１０８Ａ、１０８Ｂとの間が離間した場合、その離間した空間で、部分放電を発生させる場合もある。 The insulating sheets 110A and 110B are formed to be thin in order to improve heat dissipation. However, the insulating sheets 110A and 110B play a role of insulation between the circuit body 150 and the cooling bodies 108A and 108B, and the insulation sheets 110A and 110B and the circuit body 150 are insulated. When the sheets 110A and 110B are separated from the cooling bodies 108A and 108B, partial discharge may be generated in the separated spaces.
　そこで本実施形態では、回路体１５０と絶縁シート１１０Ａ、１１０Ｂとの接触面の直角方向から見た場合、絶縁シート１１０Ａ、１１０Ｂは回路体１５０と冷却体１０８Ａ、１０８Ｂよりも小さく形成された辺を有し、絶縁シート１１０Ａ、１１０Ｂの前記辺は、被覆材１１１が噛み込まれるような凹凸型に形成している。 Therefore, in this embodiment, when viewed from the direction perpendicular to the contact surface between the circuit body 150 and the insulating sheets 110A and 110B, the insulating sheets 110A and 110B have sides formed smaller than the circuit body 150 and the cooling bodies 108A and 108B. And the sides of the insulating sheets 110 </ b> A and 110 </ b> B are formed in a concavo-convex shape so that the covering material 111 is bitten.
　実施例について、図４から図９を用いながら説明する。 Examples will be described with reference to FIGS.
　図４は、本実施例のパワー半導体装置１００の断面構造図である。図５は、パワー半導体装置１００の絶縁シート１１０Ａ及び絶縁シート１１０Ｂの部分に着目した内部平面図である。図６は、絶縁シート１１０Ａ及び絶縁シート１１０Ｂの外形に凹凸型を形成するメカニズムを説明するための図であり、絶縁シート１１０Ａ及び絶縁シート１１０Ｂを押圧する前の状態を示す。図７は、絶縁シート１１０Ａ及び絶縁シート１１０Ｂの外形に凹凸型を形成するメカニズムを説明するための図であり、絶縁シート１１０Ａ及び絶縁シート１１０Ｂを押圧した後の状態を示す。図８は、図１の本実施例のパワー半導体装置１００のＢ部の拡大断面図である。また、図９は、パワー半導体装置１００の回路体１５０の断面構造図である。 FIG. 4 is a cross-sectional structure diagram of the power semiconductor device 100 of the present embodiment. FIG. 5 is an internal plan view focusing on the insulating sheet 110 </ b> A and the insulating sheet 110 </ b> B of the power semiconductor device 100. FIG. 6 is a diagram for explaining a mechanism for forming a concavo-convex shape on the outer shape of the insulating sheet 110A and the insulating sheet 110B, and shows a state before the insulating sheet 110A and the insulating sheet 110B are pressed. FIG. 7 is a diagram for explaining a mechanism for forming a concavo-convex pattern on the outer shape of the insulating sheet 110A and the insulating sheet 110B, and shows a state after the insulating sheet 110A and the insulating sheet 110B are pressed. FIG. 8 is an enlarged cross-sectional view of part B of the power semiconductor device 100 of this embodiment shown in FIG. FIG. 9 is a cross-sectional structure diagram of the circuit body 150 of the power semiconductor device 100.
　実施例のパワー半導体装置の作製方法について以下説明する。 A method for manufacturing the power semiconductor device of the example will be described below.
　まず図９を用いて、回路体１５０の作製方法について説明する。 First, a manufacturing method of the circuit body 150 will be described with reference to FIG.
　パワー半導体素子１０１は、導体板１０２Ａ及び導体板１０２Ｂに接合材１０３Ａ及び接合材１０３Ｂを介して固着される。　導体板１０２Ａ及び導体板１０２Ｂは、例えば銅、銅合金、あるいはアルミニウム、アルミニウム合金などにより形成されている。　接合材１０３Ａ及び接合材１０３Ｂは、主に半田が使用されるが、樹脂中に銀などの金属粉を分散させた導電ペーストなども使われる。　パワー半導体素子１０１としては、ＩＧＢＴやダイオードがあり、現状主にＳｉデバイスが使用されているが、ＳｉＣなどのデバイスを用いることができる。 The power semiconductor element 101 is fixed to the conductor plate 102A and the conductor plate 102B via the bonding material 103A and the bonding material 103B. The conductor plate 102A and the conductor plate 102B are made of, for example, copper, copper alloy, aluminum, aluminum alloy, or the like. Solder is mainly used for the bonding material 103A and the bonding material 103B, but a conductive paste in which metal powder such as silver is dispersed in resin is also used. There are IGBTs and diodes as the power semiconductor element 101, and Si devices are mainly used at present, but devices such as SiC can be used.
　そして、パワー半導体素子１０１と導体板１０２Ａと導体板１０２Ｂを封止樹脂１０６を用いてトランスファーモールド等の技術により封止し、回路体１５０が完成する。 Then, the power semiconductor element 101, the conductor plate 102A, and the conductor plate 102B are sealed by a technique such as transfer molding using the sealing resin 106, and the circuit body 150 is completed.
　封止樹脂１０６としては、通常エポキシ樹脂を主体とする樹脂が使用され、他の部材との熱応力を小さくするため、熱膨張率の調整のためシリカやアルミナなどのフィラーを樹脂中に分散させたものが使われる。 As the sealing resin 106, a resin mainly composed of an epoxy resin is usually used. In order to reduce thermal stress with other members, fillers such as silica and alumina are dispersed in the resin to adjust the thermal expansion coefficient. Is used.
　入出力端子１０４は、その一部が封止樹脂１０６から突出する。 A part of the input / output terminal 104 protrudes from the sealing resin 106.
　続いて図４から図８を用いてパワー半導体装置１００の作製方法について説明する。図４においてケース１０９は、外周に放熱フィン１０７を形成した冷却体１０８Ａ及び冷却体１０８Ｂと、側壁部と、回路体１５０を挿入するための挿入口を形成するシール部と、から構成する。 Subsequently, a manufacturing method of the power semiconductor device 100 will be described with reference to FIGS. In FIG. 4, the case 109 includes a cooling body 108 </ b> A and a cooling body 108 </ b> B in which heat dissipating fins 107 are formed on the outer periphery, a side wall portion, and a seal portion that forms an insertion port for inserting the circuit body 150.
　ケース１０９の内部に、回路体１５０の導体板１０２Ａ及び導体板１０２Ｂが露出している面の両面に絶縁シート１１０Ａ及び絶縁シート１１０Ｂを配置した状態で回路体１５０を挿入する。 In the case 109, the circuit body 150 is inserted in a state where the insulating sheet 110A and the insulating sheet 110B are disposed on both surfaces of the surface of the circuit body 150 where the conductor plate 102A and the conductor plate 102B are exposed.
　ここで、冷却体１０８Ａ、冷却体１０８Ｂ、絶縁シート１１０Ａ、絶縁シート１１０Ｂと回路体１５０の配置関係について説明する。図４のように、回路体１５０と絶縁シート１１０Ａ及び絶縁シート１１０Ｂとの接触面の直角方向から見た場合、絶縁シート１１０Ａ及び絶縁シート１１０Ｂは回路体１５０と冷却体１０８Ａ及び冷却体１０８Ｂよりも小さく形成された辺を有するようにする。 Here, the arrangement relationship between the cooling body 108A, the cooling body 108B, the insulating sheet 110A, the insulating sheet 110B, and the circuit body 150 will be described. As shown in FIG. 4, when viewed from the direction perpendicular to the contact surface between the circuit body 150 and the insulating sheet 110A and the insulating sheet 110B, the insulating sheet 110A and the insulating sheet 110B are more than the circuit body 150, the cooling body 108A, and the cooling body 108B. Try to have small sides.
　図５を用いて、接触面の直角方向から見た場合の配置関係について説明する。最外周の破線１０８Ａ’及び１０８Ｂ’は冷却体１０８Ａ及び１０８Ｂの外周形状を示す。実線１５０Ａは、回路体１５０の絶縁シート１１０Ａ又は絶縁シート１１０Ｂとの接触面の外周形状を示す。 Referring to FIG. 5, the arrangement relationship when viewed from the direction perpendicular to the contact surface will be described. The outermost broken lines 108A 'and 108B' indicate the outer peripheral shapes of the cooling bodies 108A and 108B. A solid line 150A indicates the outer peripheral shape of the contact surface of the circuit body 150 with the insulating sheet 110A or the insulating sheet 110B.
　内周側の破線１１０Ａ’及び１１０Ｂ’は、プレスにより押圧する前の絶縁シート１１０Ａ又は絶縁シート１１０Ｂの外周形状を示す。また、最内周側の点線は、導体板１０２Ａ及び１０２Ｂが封止樹脂１０６から露出した状態を示す。 The inner peripheral broken lines 110A 'and 110B' indicate the outer peripheral shape of the insulating sheet 110A or the insulating sheet 110B before being pressed by the press. Further, the dotted line on the innermost peripheral side shows a state in which the conductor plates 102A and 102B are exposed from the sealing resin 106.
　絶縁シートの外形１１０Ａ’、１１０Ｂ’は、冷却体の内壁面外形１０８Ａ’、１０８Ｂ’と回路体１５０の絶縁シートとの接触面１５０Ａよりも小さくなるように形成する。 The outer shapes 110A 'and 110B' of the insulating sheet are formed to be smaller than the contact surface 150A between the inner wall surface shapes 108A 'and 108B' of the cooling body and the insulating sheet of the circuit body 150.
　また、プレスにより押圧する前の絶縁シート１１０Ａの外周形状１１０Ａ’及びプレスにより押圧する前の絶縁シート１１０Ｂの外周形状１１０Ｂ’は、導体板１０２Ａ及び１０２Ｂの外形よりも大きくなるように形成する。 Further, the outer peripheral shape 110A ′ of the insulating sheet 110A before being pressed by the press and the outer peripheral shape 110B ′ of the insulating sheet 110B before being pressed by the press are formed to be larger than the outer shapes of the conductor plates 102A and 102B.
　ケース１０９内に回路体１５０と絶縁シート１１０Ａ及び絶縁シート１１０Ｂを上記所定の位置に配置させた後、これらを真空プレス機にセットし、冷却体１０８Ａ及び１０８Ｂの放熱フィン１０７側を高温下で押圧する。これにより、冷却体１０８Ａと絶縁シート１１０Ａの間と、絶縁シート１１０Ａと回路体１５０との間と、冷却体１０８Ｂと絶縁シート１１０Ｂの間と、さらに絶縁シート１１０Ｂと回路体１５０との間とを接着させる。この押圧の工程により、絶縁シート１１０Ａまたは絶縁シート１１０Ｂの外形には、図５に示すような凹凸形状１１０Ａ’’及び１１０Ｂ’’が形成される。 After the circuit body 150, the insulating sheet 110A, and the insulating sheet 110B are arranged at the predetermined positions in the case 109, they are set in a vacuum press machine, and the radiating fin 107 side of the cooling bodies 108A and 108B is pressed at a high temperature. To do. Thus, between the cooling body 108A and the insulating sheet 110A, between the insulating sheet 110A and the circuit body 150, between the cooling body 108B and the insulating sheet 110B, and between the insulating sheet 110B and the circuit body 150. Adhere. As a result of this pressing step, the concavo-convex shapes 110A ″ and 110B ″ as shown in FIG. 5 are formed on the outer shape of the insulating sheet 110A or the insulating sheet 110B.
　図６及び図７を用いて絶縁シート１１０Ａ及び１１０Ｂの外周に形成される凹凸形状１１０Ａ’’及び１１０Ｂ’’の形成メカニズムを説明する。 The formation mechanism of the concavo-convex shapes 110A "and 110B" formed on the outer periphery of the insulating sheets 110A and 110B will be described with reference to FIGS.
　図６及び図７は、冷却体１０８Ａまたは冷却体１０８Ｂの押圧する方向から見た絶縁シート１１０（絶縁シート１１０Ａ又は１１０Ｂ）の表面模式図である。 6 and 7 are schematic views of the surface of the insulating sheet 110 (insulating sheet 110A or 110B) viewed from the pressing direction of the cooling body 108A or the cooling body 108B.
　図６は押圧する前、図７は押圧後の状態を表しており、それぞれの図において図の下側の辺が絶縁シート１１０の外周形状の状態を表している。 FIG. 6 shows a state before pressing, and FIG. 7 shows a state after pressing. In each drawing, the lower side of the drawing shows the outer peripheral shape of the insulating sheet 110.
　図６及び図７において絶縁シート１１０は、樹脂１３２中に粒度が異なる無機フィラー１３１を分散含有させたもので構成される。 6 and 7, the insulating sheet 110 is composed of a resin 132 in which inorganic fillers 131 having different particle sizes are dispersedly contained.
　無機フィラー１３１としては、パワー半導体素子１０１の発熱を冷却体１０８Ａ及び１０８Ｂに放熱するため、熱伝導性が良いものが好ましく、例えば、窒化ホウ素（ＢＮ）、窒化アルミ（ＡｌＮ）、酸化アルミニウム（Ａｌ２Ｏ３）などが使用できる。 The inorganic filler 131 is preferably one having good thermal conductivity in order to dissipate the heat generated by the power semiconductor element 101 to the cooling bodies 108A and 108B. For example, boron nitride (BN), aluminum nitride (AlN), aluminum oxide (Al 2 O 3 ) or the like can be used.
　図６において、押圧の工程では、樹脂１３２が硬化する前の状態である絶縁シート１１０に熱を加え、樹脂１３２の粘度を低下させる。樹脂１３２の粘度が下がった状態で、冷却体１０８Ａまたは冷却体１０８Ｂのフィン放熱１０７側の面を押圧する。 In FIG. 6, in the pressing step, heat is applied to the insulating sheet 110 that is in a state before the resin 132 is cured to reduce the viscosity of the resin 132. With the viscosity of the resin 132 lowered, the surface of the cooling body 108A or the cooling body 108B on the fin heat radiation 107 side is pressed.
　絶縁シート１１０の外周形状１１０Ａ’及び１１０Ｂ’は冷却体１０８Ａまたは冷却体１０８Ｂの内壁面と回路体１５０の絶縁シート１１０との接触面よりも小さく形成されているため、絶縁シート１１０の外周形状１１０Ａ’及び１１０Ｂ’にも押圧がかかり、粘度が低下した状態の樹脂１３２に、絶縁シート１１０の外形方向に流れようとする力（ここでこの力を掃流力と呼ぶ）が働く。 Since the outer peripheral shapes 110A ′ and 110B ′ of the insulating sheet 110 are formed smaller than the contact surface between the inner wall surface of the cooling body 108A or the cooling body 108B and the insulating sheet 110 of the circuit body 150, the outer peripheral shape 110A of the insulating sheet 110. A force (this force is referred to as a scavenging force) is applied to the resin 132 in a state where the pressure is also applied to “and 110B” and the viscosity is lowered, in order to flow in the outer direction of the insulating sheet 110.
　この掃流力は、絶縁シート１１０の樹脂１３２の粘度と押圧する圧力で制御することができ、粘度が低く、圧力が高いほど掃流力を大きくすることができる。 This scavenging force can be controlled by the viscosity of the resin 132 of the insulating sheet 110 and the pressing pressure. The lower the viscosity and the higher the pressure, the larger the scavenging force.
　この掃流力に対し、樹脂１３２中に分散させた無機フィラー１３１には抵抗力が働き、この抵抗力はフィラー１３１の粒径と重量に比例し、大きな無機フィラー１３１ほど抵抗力が大きくなる。掃流力から抵抗力を差し引いた力が絶縁シート１１０の外形方向へ樹脂１３２が流れる力となる。 The resistance force acts on the inorganic filler 131 dispersed in the resin 132 against the scavenging force, and this resistance force is proportional to the particle size and weight of the filler 131, and the resistance force increases as the inorganic filler 131 increases. The force obtained by subtracting the resistance force from the scavenging force becomes the force through which the resin 132 flows in the outer direction of the insulating sheet 110.
　図７は、押圧後の絶縁シート１１０の状態を表している。樹脂１３２や小さな無機フィラー１３１が分布している部分はより外形方向に押し出され、大きな無機フィラー１３１が分布している部分は押し出されず、結果として押圧後、絶縁シート１１０の外形に凹凸型を形成させることができる。 FIG. 7 shows the state of the insulating sheet 110 after being pressed. The portion where the resin 132 and the small inorganic filler 131 are distributed is pushed out in the outer direction, and the portion where the large inorganic filler 131 is distributed is not pushed out. As a result, after pressing, an uneven shape is formed in the outer shape of the insulating sheet 110. Can be made.
　無機フィラー１３１の大きさによって掃流力に対する抵抗力が変化し、その差分が大きいほどより絶縁シート１１０の外形に形成される凹凸が大きくなる。このため、凹凸を形成するためには絶縁シート１１０中に粒径１０μｍ以上のフィラーを含有することが好ましい。 The resistance to the scavenging force changes depending on the size of the inorganic filler 131, and the unevenness formed on the outer shape of the insulating sheet 110 increases as the difference increases. For this reason, in order to form unevenness, the insulating sheet 110 preferably contains a filler having a particle size of 10 μm or more.
　プレス押圧の状態で絶縁シート１１０の硬化がなされるまで所定時間保持した後、プレス機から回路体１５０、絶縁シート１１０、ケース１０９が一体形成されたものを取り出し、ケース１０９の端子側の開口部分から被覆材１１１（ポッティング樹脂）を流し込み、ケース１０９の内部空間に被覆材１１１を充填形成させる。 After holding for a predetermined time until the insulating sheet 110 is cured in the press-pressed state, the integrated circuit body 150, the insulating sheet 110, and the case 109 are taken out from the press machine, and the opening portion on the terminal side of the case 109 is taken out. Then, a covering material 111 (potting resin) is poured into the interior space of the case 109 to fill and form the covering material 111.
　この時、絶縁シート１１０の外形の凹凸形状部分にも、図４に示される被覆材１１１が形成される。図９は、図４に示す本実施例のパワー半導体装置のＢ部における断面図である。図８に示されるように、樹脂１３２や小さな無機フィラー１３１が押圧された絶縁シート１１０の外形に被覆材１１１が噛み込まれるように形成される。 At this time, the covering material 111 shown in FIG. 4 is also formed on the uneven portion of the outer shape of the insulating sheet 110. FIG. 9 is a cross-sectional view of part B of the power semiconductor device of this embodiment shown in FIG. As shown in FIG. 8, the covering material 111 is formed so as to be bitten into the outer shape of the insulating sheet 110 pressed with the resin 132 or the small inorganic filler 131.
　その後、高温槽内に置き、所定の条件で被覆材１１１を硬化させ、パワー半導体装置１００が完成する。 Thereafter, the power semiconductor device 100 is completed by placing it in a high-temperature bath and curing the covering material 111 under predetermined conditions.
　（温度サイクル試験）
　実施例と図１に示した比較例のパワー半導体装置とを比較することにより本実施形態の効果を検証した。具体的には、パワー半導体装置１００の温度サイクル試験（ΔＴ＝１６５度）を実施し、所定サイクル毎の部分放電試験を実施することで評価した。 (Temperature cycle test)
The effect of this embodiment was verified by comparing the example and the power semiconductor device of the comparative example shown in FIG. Specifically, a temperature cycle test (ΔT = 165 degrees) of the power semiconductor device 100 was performed, and evaluation was performed by performing a partial discharge test every predetermined cycle.
　絶縁シート１１０の外形と被覆材１１１の離間が、絶縁シート１１０と冷却体１０８Ａ又は１０８Ｂとの離間、または絶縁シート１１０と回路体１５０との離間に進展し、その離間部に高電圧が印加されると部分放電という現象が生じる。 The separation between the outer shape of the insulating sheet 110 and the covering material 111 advances to the separation between the insulating sheet 110 and the cooling body 108A or 108B, or the separation between the insulating sheet 110 and the circuit body 150, and a high voltage is applied to the separation portion. Then, a phenomenon called partial discharge occurs.
　部分放電試験は、パワー半導体装置１００の全ての入出力端子１０４（交流出力端子１０４Ａ、直流出力端子１０４Ｂ、制御端子１０４Ｃ）を同電位となるよう短絡し、部分放電試験機にて入出力端子１０４とケース１０９との間に交流電圧を印加し、徐々に電圧を上昇させ部分放電の電荷量が５ｐＣを超えた時の電圧を部分放電開始電圧とした。なお、印加電圧の最大は２．５ｋＶｒｍｓとして、２．５ｋＶｒｍｓで部分放電が発生しないサンプルについては、グラフ化するため便宜上部分放電電圧を２．５ｋＶｒｍｓとした。 In the partial discharge test, all the input / output terminals 104 (AC output terminal 104A, DC output terminal 104B, and control terminal 104C) of the power semiconductor device 100 are short-circuited to have the same potential, and the input / output terminals 104 are tested using a partial discharge tester. An AC voltage was applied between the case 109 and the case 109, and the voltage was gradually increased to set the voltage when the partial discharge charge amount exceeded 5 pC as the partial discharge start voltage. Note that the maximum applied voltage was 2.5 kVrms, and the partial discharge voltage was set to 2.5 kVrms for convenience in order to graph the sample in which partial discharge did not occur at 2.5 kVrms.
　図１０に、実施例及び比較例に対し。温度サイクル試験を実施し、所定サイクル毎にパワー半導体装置の部分放電開始電圧を測定した結果を示す。図１０において、横軸は温度サイクルのサイクル数、縦軸は各温度サイクル時点での部分放電開始電圧を表す。 FIG. 10 shows an example and a comparative example. The temperature cycle test is implemented, and the result of measuring the partial discharge start voltage of the power semiconductor device every predetermined cycle is shown. In FIG. 10, the horizontal axis represents the number of temperature cycles, and the vertical axis represents the partial discharge start voltage at each temperature cycle.
　図１０から分かるように、実施例及び比較例のパワー半導体装置において、温度サイクル１５００サイクル経過時点では、印加電圧の最大値２．５ｋＶｒｍｓにおいても部分放電の発生は無かった。しかし、比較例では、温度サイクル２０００サイクル経過後において部分放電開始電圧は２．３ｋＶｒｍｓに低下した。その後も比較例においては、試験サイクルの経過と伴に部分放電開始電圧が低下した。この部分放電開始電圧の低下は、絶縁シート１１０の外形部と被覆材１１１との界面が離間し、その部分を起点として冷却体１０８Ａ又は１０８Ｂと絶縁シート１１０の離間に進展、その離間した空間に電界が集中し、部分放電が発生したためである。比較例では、絶縁シート１１０の外形部が直線形状であり、被覆材の密着（接着）強度が弱く、そのために離間が発生した。 As can be seen from FIG. 10, in the power semiconductor devices of the example and the comparative example, no partial discharge occurred even at the maximum value of 2.5 kVrms when the temperature cycle was 1500 cycles. However, in the comparative example, the partial discharge start voltage decreased to 2.3 kVrms after 2000 temperature cycles. After that, in the comparative example, the partial discharge start voltage decreased with the progress of the test cycle. The decrease in the partial discharge start voltage is caused by the interface between the outer portion of the insulating sheet 110 and the covering material 111 being separated from each other, and starting from that portion, the cooling body 108A or 108B and the insulating sheet 110 are separated from each other. This is because the electric field is concentrated and partial discharge occurs. In the comparative example, the outer shape portion of the insulating sheet 110 was a linear shape, and the adhesion (adhesion) strength of the covering material was weak, and therefore separation occurred.
　これに対し、実施例では、温度サイクル４０００サイクル経過後も２．５ｋＶｒｍｓでの部分放電の発生は無かった。実施例では絶縁シート１１０の外形部に凹凸型を有し、その部分に被覆材１１１が噛み込むように形成されるため、絶縁シート１１０と被覆材１１１との密着（接着）強度が高くできる。 In contrast, in the example, no partial discharge occurred at 2.5 kV rms even after 4000 temperature cycles. In the embodiment, since the outer shape of the insulating sheet 110 has a concavo-convex shape and the covering material 111 is formed so as to bite into that portion, the adhesion (adhesion) strength between the insulating sheet 110 and the covering material 111 can be increased.
　これにより、パワー半導体装置１００の動作、停止による温度変化によって生じる可能性のある絶縁シート１１０と被覆材１１１の離間を防止できる。この離間防止により、部分放電の発生を防止でき、信頼性の高いパワー半導体装置１００を得ることができる。 Thereby, it is possible to prevent the insulation sheet 110 and the covering material 111 from being separated due to a temperature change caused by the operation and stop of the power semiconductor device 100. By preventing this separation, the occurrence of partial discharge can be prevented, and a highly reliable power semiconductor device 100 can be obtained.
１００…パワー半導体装置、１０１…パワー半導体素子、１０２Ａ…導体板、１０２Ｂ…導体板、１０３Ａ…接合材、１０３Ｂ…接合材、１０４…入出力端子、１０４Ａ…交流出力端子、１０４Ｂ…直流入力端子、１０４Ｃ…制御端子、１０５…金属細線、１０６…封止樹脂、１０７…放熱フィン、１０８Ａ…冷却体、１０８Ａ’ …冷却体１０８Ａの外周形状、１０８Ｂ’ …冷却体１０８Ｂの外周形状、１０８Ｂ…冷却体、１０９…ケース、１１０Ａ…絶縁シート、１１０Ｂ…絶縁シート、１１０Ａ’ …プレスにより押圧する前の絶縁シート１１０Ａの外周形状、１１０Ｂ’ …プレスにより押圧する前の絶縁シート１１０Ｂの外周形状、１１０Ａ’’ …凹凸形状、１１０Ｂ’’ …凹凸形状、１１１…被覆材、１２０Ａ…絶縁シートと被覆材の離間、１２０Ｂ…絶縁シートと被覆材の離間、１２１…冷却体と絶縁シートの離間、１２２…回路体と絶縁シートの離間、１３１…無機フィラー１３２…樹脂、１５０…回路体、１５０Ａ…回路体１５０と絶縁シート１１０Ａ又は絶縁シート１１０Ｂとの接触面の外周形状 DESCRIPTION OF SYMBOLS 100 ... Power semiconductor device, 101 ... Power semiconductor element, 102A ... Conductor plate, 102B ... Conductor plate, 103A ... Bonding material, 103B ... Bonding material, 104 ... Input / output terminal, 104A ... AC output terminal, 104B ... DC input terminal, 104C ... Control terminal, 105 ... Metal thin wire, 106 ... Sealing resin, 107 ... Heat radiating fin, 108A ... Cooling body, 108A '... Outer peripheral shape of cooling body 108A, 108B' ... Outer peripheral shape of cooling body 108B, 108B ... Cooling body , 109, case, 110A, insulating sheet, 110B, insulating sheet, 110A ′ ... outer peripheral shape of insulating sheet 110A before pressing by press, 110B ′ ... outer peripheral shape of insulating sheet 110B before pressing by pressing, 110A '' ... Uneven shape, 110B '' ... Uneven shape, 111 ... Coating material, 120A ... Insulating sheet Spacing material separation, 120B: insulation sheet and coating material separation, 121 ... cooling body and insulation sheet separation, 122 ... circuit body and insulation sheet separation, 131 ... inorganic filler 132 ... resin, 150 ... circuit body, 150A ... Peripheral shape of contact surface between circuit body 150 and insulating sheet 110A or insulating sheet 110B

Claims (4)

  1. 　パワー半導体素子を有する回路体と、
    　前記回路体と対向する冷却体と、
    　前記回路体と前記冷却体の間の空間に配置されかつ無機フィラーを含有する絶縁シートと、
    　前記回路体と前記冷却体と前記絶縁シートに接する被覆材と、を備え、
    　前記回路体と前記絶縁シートとの接触面の直角方向から見た場合、前記絶縁シートは前記回路体と前記冷却体よりも小さく形成された辺を有し、
    　前記絶縁シートの前記辺は、前記被覆材が噛み込まれるような凹凸型に形成されるパワー半導体装置。     A circuit body having a power semiconductor element;
    A cooling body facing the circuit body;
    An insulating sheet disposed in a space between the circuit body and the cooling body and containing an inorganic filler;
    The circuit body, the cooling body, and a covering material in contact with the insulating sheet,
    When viewed from the direction perpendicular to the contact surface between the circuit body and the insulating sheet, the insulating sheet has sides formed smaller than the circuit body and the cooling body,
    The power semiconductor device, wherein the side of the insulating sheet is formed in a concavo-convex shape in which the covering material is bitten.
  2. 　請求項１に記載のパワー半導体装置において、
    　前記回路体と前記絶縁シートとの接触面の直角方向から見た場合、前記絶縁シートは前記回路体の導体板よりも大きく形成された辺を有しているパワー半導体装置。     The power semiconductor device according to claim 1,
    The power semiconductor device, wherein the insulating sheet has a side formed larger than a conductor plate of the circuit body when viewed from a direction perpendicular to a contact surface between the circuit body and the insulating sheet.
  3. 　請求項１または２に記載のパワー半導体装置において、
    　前記絶縁シートは、樹脂中に無機フィラーを分散含有させたものであり、少なくとも粒径が１０μｍよりも大きいフィラーを含有するパワー半導体装置。     The power semiconductor device according to claim 1 or 2,
    The insulating sheet is a power semiconductor device in which an inorganic filler is dispersed and contained in a resin, and at least a filler having a particle size larger than 10 μm.
  4. 　パワー半導体素子を有する回路体と冷却体により絶縁シートを挟む第１工程と、
    　未硬化状態の前記絶縁シートに熱を加えて当該絶縁シートを構成する樹脂の粘度を低下させた状態で、前記回路体又は前記冷却体を加圧することで、当該樹脂を流し出すことで前記絶縁シートの辺に凹凸型を形成する第２工程と、
    　前記前記絶縁シートの前記凹凸型に被覆材を充填する第３工程と、を備えるパワー半導体装置の製造方法。     A first step of sandwiching an insulating sheet between a circuit body having a power semiconductor element and a cooling body;
    Insulating the insulating sheet by pouring out the resin by pressurizing the circuit body or the cooling body in a state where the viscosity of the resin constituting the insulating sheet is reduced by applying heat to the uncured insulating sheet. A second step of forming a concavo-convex mold on the side of the sheet;
    And a third step of filling the concave-convex mold of the insulating sheet with a covering material.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014123644A (en) * 2012-12-21 2014-07-03 Mitsubishi Electric Corp Power semiconductor device
WO2017110614A1 (en) * 2015-12-25 2017-06-29 三菱電機株式会社 Semiconductor device and manufacturing method therefor
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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