Electronic switching device and inverter-integrated electric compressor equipped with it

Abstract

An electronic switching device comprising a conductor-free housing component mounted on a circuit substrate, wherein the conductor-free housing component is a power switching element, and in the circuit substrate at least one pair of through holes is formed in a width direction of the power switching element for examination in order to be positioned near the power switching element.

Description

Technical FieldThe present invention relates to an electronic switching device including leadless case members mounted on a circuit substrate, and an inverter-integrated electric compressor equipped with the electronic switching device.Prior ArtHeretofore, as an electric compressor for use in a vehicle air conditioner, an inverter integrated electric compressor has been employed in which an inverter switching portion is mounted on a housing in consideration of switching noises. In this case, as disclosed in JP 2004-190 547 A, for example, the inverter switching section is made up of an electronic switching device in which a plurality of power switching elements are mounted on a circuit substrate and a motor is driven in the case with the power switching elements.Moreover, in recent years, the power switching elements have been constructed from lead-free housing components. By using the non-conductive case members, on-resistance is reduced, current is increased, parasitic inductance is decreased, and the like is obtained, and power increase can be expected, as disclosed in JP H09-8 444 A, for example.In addition, DE 11 2013 004 490 T5 relates to a power converter device having a power semiconductor module, a drive circuit board mounted with a drive circuit, an AC-side relay conductor for transmitting the AC current, and an AC connection element. The power semiconductor module includes an AC side terminal connected to the AC side relay conductor and a control side terminal connected to the drive circuit board. The AC connector is provided on the opposite side to the power semiconductor module through the drive circuit board. The drive circuit board includes a transformer for transforming a low voltage to a high voltage and supplying the transformed voltage to the drive circuit, and a line for connecting the transformer to the drive circuit. Further, the drive circuit board forms a through hole provided on the side opposite to the transformer with the drive circuit interposed therebetween. The AC side relay conductor is connected to the AC side connector through the through hole.The publication "I-proper 520 positional current sample" Thurlby Thandar Instruments Ltd.; Huntingdon, 2024 (Brochure Part No. 82100-1440 Iss. 1A); URL: https: / / web.archive.org / web / 20160409585638 / http: / / www.aimtti.com / sites / default / files / brochure / prec-iprober520-5p.pdf) relates to a measuring device for measuring the current of conductor tracks.US 2013 / 0 077 255 A1 relates to a semiconductor control device having a plurality of semiconductor modules each having a cooling member and a semiconductor element, a circuit board on which a control element that controls the plurality of semiconductor modules is mounted, and a housing in which the plurality of semiconductor modules and the circuit board are mounted, respectively. The housing is provided with a cylindrical side wall forming an inner space inside the housing, and at both ends of the side wall, a first opening and a second opening are formed opposite to each other, respectively. The plurality of semiconductor modules includes a first semiconductor module mounted on the side wall on a side of the first opening and a second semiconductor module mounted on the side wall on a side of the second opening. The circuit board is positioned between the first semiconductor module and the second semiconductor module in the internal space.JP 2008-220 060 A relates to a power module connected between a DC power supply of a power conversion apparatus for driving an AC load from a DC power supply and an AC power supply. Second semiconductor elements constituting a circuit of a current sensor for detecting a current of the power module are mounted on a power module drive board equipped with first semiconductor elements for driving the power module.SUMMARY OF THE INVENTIONProblems to be Solved by the InventionHowever, when power switching elements are made of non-conductive case members, the lead terminals are disproportionately too short (non-conductive), so that a current probe cannot pass through the terminals in a state where the components are mounted on a circuit substrate. Consequently, there has been a problem that element characteristics cannot be measured, for example, in evaluation at a development stage or during substrate inspection in mass production.In addition, a parasitic inductance of the terminal changes when a clearance is provided for the current probe, for example, by extending the terminal. Therefore, an operation is different from an original operation, so that the element characteristics cannot be accurately measured.The present invention has been developed to solve such conventional technical problems, and an object thereof is to provide an electronic switching device capable of accurately measuring element characteristics in a state in which power switching elements made of non-conductive case members are mounted on a circuit substrate, and an inverter-integrated electric compressor equipped with the electronic switching device.Means for Solving the ProblemsAn electronic switching device of the invention according to claim 1 includes a leadless case member mounted on a circuit substrate, and is characterized in that the leadless case member is a power switching element, and at least a pair of through holes are formed in the circuit substrate in a width direction of the power switching element for inspection so as to be disposed in the vicinity of the power switching element.An electronic switching device of the invention according to claim 2 includes a leadless case member mounted on a circuit substrate, characterized in that the leadless case member is a power switching element, and a plurality of power switching elements are arranged on the circuit substrate in parallel in its width direction and connected in parallel to each other to form a power switching element group, and at least a pair of through holes in a width direction of the power switching element group for inspection are formed in the circuit substrate to be positioned in the vicinity of the power switching element group.The electronic switching device of the invention according to claim 3 is characterized in that the power switching element in the above-mentioned respective inventions includes a semiconductor chip molded from a resin, terminals protruding from the resin, and wire parts molded from the resin for connecting the semiconductor chip to the terminals, and the through holes are formed to correspond to a region where the wire parts are arranged.An inverter integrated electric compressor of the invention according to claim 4 is characterized by comprising a housing accommodating a motor and an inverter switching portion made up of the electronic switching device according to the above respective inventions for energizing the motor.The inverter integrated electric compressor of the invention according to claim 5 is characterized in that in the above invention, the inverter circuit part is fixed to the casing, and in this state, the power switching element is disposed in a heat exchanging relationship with the casing via a filler material for heat conduction.The inverter integrated electric compressor of the invention according to claim 6 is characterized in that in the invention according to claim 4, the inverter switching portion is fixed to the housing, and in this state, the power switching element is disposed in a heat exchanging relationship with the housing via a seat for heat conduction.The inverter integrated electric compressor of the invention according to claim 7 is characterized in that in the invention according to claim 4, the inverter switching portion is fixed to the housing by bonding the circuit substrate to the housing with an adhesive.Advantageous Effect of the InventionAccording to the invention of claim 1, in an electronic switching device including a leadless case member mounted on a circuit substrate, the leadless case member is a power switching element, and at least one pair of through holes for inspection are formed in the circuit substrate so as to be positioned in the vicinity of the power switching element. Consequently, a current probe is passed through this pair of through holes, so that a current of the power switching element mounted on the circuit substrate can be measured.Consequently, even in a case where the power switching element is composed of the non-conductive case member, it is possible to examine the characteristics (current and voltage) in actual switching of the power switching element, for example, during evaluation in a development phase or in substrate inspection in mass production, and it is possible to accurately measure the characteristics during an original operation, thereby achieving quality improvement. In particular, a structure is also simple, and thus a high increase in production cost can be suppressed.In addition, as in the invention of claim 2, on the circuit substrate, a plurality of power switching elements are arranged in parallel in the widthwise direction thereof and connected in parallel to each other to form a power switching element group. In this case, in the circuit substrate, at least a pair of through holes are formed in the width direction of the power switching element group for inspection so as to be positioned in the vicinity of the power switching element group. Consequently, the current probe is passed through this pair of through holes, so that the current of the power switching element group mounted on the circuit substrate can be measured.Thus, even in the case where the plurality of power switching elements composed of the non-conductive case members are arranged in parallel to each other and connected in parallel to each other to form the power switching element group, it is possible to examine the characteristics in the actual switching of the power switching element group, for example, during the evaluation in the development phase or during the substrate inspection in mass production, and it is possible to accurately measure the characteristics during the original operation and thus to achieve improvement in quality. Also in this case, the structure is similarly simple, and thus the high increase in production cost can be suppressed.More specifically, as in the invention of claim 3, the power switching element comprises a semiconductor chip molded from a resin, terminals protruded from the resin, and wire parts molded from the resin to connect the semiconductor chip to the terminals. In this case, the through holes are formed to correspond to a region where the wire members are arranged. Consequently, it is possible to more accurately measure a current flowing through the wire members with the current probe.The electronic switching device of each of the above inventions is particularly suitable for the configuration of an inverter switching portion of an inverter integrated electric compressor that includes a housing in which a motor is accommodated and that includes the inverter switching portion for supplying power to the motor as in the invention of claim 4.For example, as in the invention of claim 5, the inverter switching portion is fixed to the case, and in this state, the power switching element is disposed in a heat exchanging relationship with the case via a filler material for heat conduction. In this case, it can be visually confirmed whether or not the filling material is sufficiently filled by using the through holes. Consequently, it is possible to prevent in advance the disadvantage that severe defects such as smoking and burning due to cooling defects of the power switching elements in the casing occur.In addition, as in the invention of claim 6, the inverter switching portion is fixed to the casing, and in this state, the power switching element is disposed in a heat exchanging relationship with the casing via a seat for heat conduction. In this case as well, it can be visually confirmed whether or not the seat is sufficiently closely contacted for heat conduction by using the through holes. Thereby, the disadvantage that severe failures such as smoke and burning due to a cooling failure of the power switching elements in the casing can be prevented in advance.In addition, as in the invention of claim 7, the inverter switching portion is fixed to the case by bonding the circuit substrate with an adhesive. In this case, it can be confirmed whether or not the adhesive is sufficiently cured by using the through holes. Consequently, it is possible to prevent in advance the disadvantage that, for example, errors due to mounting defects of the inverter switching portion to the case occur in the circuit components.Brief Description of the DrawingsFIG. 1 is a perspective view of an inverter-integrated electric compressor of an embodiment to which an electronic switching device of the present invention is applied; FIG. 2 is a perspective view illustrating a state in which a cover part of the inverter integrated electric compressor of FIG. 1 is removed; FIG. 3 is a plan view of a state in which the cover part of the inverter integrated electric compressor of FIG. 1 is removed from an inverter accommodating portion side; FIG. 4 is a cross-sectional view taken along the A-A line of FIG. 3 ; FIG. 5 is an exploded perspective view of a portion of an inverter switching section that incorporates a smoothing capacitor in the inverter-integrated electric compressor of FIG. 1 ; FIG. 6 is an enlarged plan view of a power switching element group portion mounted on a highly heat radiating substrate of the inverter switching portion of FIG. 5 ; FIG. 7 is a perspective plan view of a power switching element constituting the power switching element group of FIG. 6 ; FIG. 8 is a bottom perspective view of the power switching element of FIG. 7 ; FIG. 9 is a cross-sectional view taken along the B-B line of the power switching element of FIG. 7 ; FIG. 10 is a transparent diagram illustrating an internal constitution of the power switching element of FIG. 7 ; and FIG. 11 is an enlarged plan view of a case in which a single power switching element is mounted on the high heat radiating substrate.MODE FOR CARRYING OUT THE INVENTIONHereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. An inverter-integrated electric compressor 1 of the embodiment constitutes a part of a refrigerant circuit of an air conditioner for vehicles that processes air of a vehicle interior of a vehicle not shown, and includes a motor not shown, a housing 2 in which a compression mechanism (not shown) to be operated with the motor is accommodated, and an inverter switching portion 3 that drives the motor. Note that the inverter switching section 3 is an electronic switching device of the present invention.The housing 2 includes a motor housing 4 for housing the motor therein, a compression mechanism housing 6 connected to one side of the motor housing 4 in the axial direction for accommodating the compression mechanism, a compression mechanism cover 7 for closing an opening on one side of the compression mechanism housing 6, an inverter accommodating portion 8 disposed on the other side of the motor housing 4 in the axial direction, and a cover member 11 for openably closing an opening 9 on the other side of the inverter accommodating portion 8.Note that FIGS. 1 and 2 show the inverter integrated electric compressor 1 of the embodiment such that the inverter accommodating portion 8 is shown on the upper side and the compression mechanism cover 7 is shown on the lower side, however, in reality, the compressor is arranged in a lateral direction such that the compression mechanism cover 7 is arranged on the one side and the inverter accommodating portion 8 is arranged on the other side.The motor of the embodiment is composed of a three-phase synchronous motor (a brushless DC motor), and the compression mechanism is, for example, a scroll compression mechanism. The compression mechanism is driven with the motor to compress a refrigerant, thereby expelling the refrigerant into the refrigerant circuit. Then, a low-temperature gas refrigerant drawn from an evaporator (also referred to as a "heat receiver") also constituting a part of the refrigerant circuit flows through the motor housing 4. Further, the inverter accommodating portion 8 is separated from the inside of the motor housing 4 in which the motor is accommodated by a partition wall 12 formed in the motor housing 4, and the partition wall 12 is also cooled by the low-temperature gas refrigerant.(1) Structure of Inverter Switching Section 3The inverter switching section 3 has a high heat radiating substrate 14 (a circuit substrate of the present invention) on which power switching elements 13 (non-conductive case members) constituting arms of the respective phases of the three-phase inverter circuit are mounted, a control substrate 17 on which a control circuit 16 is mounted, a bus bar assembly 18 connected to the power switching elements 13 of the high heat radiating substrate 14, and a filter shape assembly 21 on which a smoothing capacitor 19 is mounted.The inverter switching section 3 converts the DC voltage supplied from a battery of the vehicle not shown into AC voltage to supply power to a stator coil (not shown) of the motor. Thus, a connection point between the power switching element 13 on an upper arm side of each phase and the power switching element 13 on a lower arm side thereof is connected to the lead terminals 22, 23, and 24 extending from the partition wall 12 of the motor housing 4 via three clamping plates 26, respectively. A power source terminal of the upper arm side power switching element 13 and a ground terminal of the lower arm side power switching element 13 are connected to a power source harness of the above battery via a high power connector 28 (composed of a bolt) referred to as an HV connector of a connector housing 27 fixed to the motor housing 4.In this case, the lead terminals 22-24 each connected to the connection point between the power switching element 13 on the upper arm side of each phase and the power switching element 13 on the lower arm side thereof pass through the partition wall 12 to be connected to the above-mentioned stator winding of the motor in the motor case 4. Further, the power source terminals and the ground terminals are connected to the power source tree via a terminal plate 29 of the filter die assembly 21, a conductive member 31 referred to as an EMC bus bar assembly, a conductive circuit substrate 32 referred to as an EMC board, a connection bus bar 33, the high-power connector 28, and others. Note that numeral 34 denotes a bus bar housing, referred to as an EMC filter housing, for accommodating therein the connection bus bar 33.(2) Structure of High Heat Radiating Substrate 14The high heat radiating substrate 14 is a thick resin molded plate from which the circuit substrate is molded, the respective power switching elements 13 and their peripheral circuit components are disposed on one surface side of the substrate, and the power switching elements 13 are configured to extend through the high heat radiating substrate 14 so as to allow heat exchange with the other surface side. Note that circuit components are also disposed around the power switching element 13 in this surface.Further, on the one side of the high heat radiating substrate 14, electrode terminals (screws) 36, 37 and 38 which are conductive to the above-mentioned connection points between the power switching elements 13 on the upper arm side of each phase and the power switching elements 13 on the lower arm side thereof are projected via the bus bars 46, 47 and 48 of the following bus bar assembly 18 and via the terminal plates 26 respectively to the lead terminals 22, 23 and 24 projected from the partition wall 12. In addition, on the one surface of the high heat radiating substrate 14, electrode terminals (screws) 42 and 43 conductive to the above-mentioned power source terminals and the ground terminals protrude to a terminal plate 44 of the filter die assembly 21 via the bus bars 49 and 50 of the bus bar assembly 18 described later to be connected thereto. Further, a connector 39 is fixed to a peripheral portion of the one surface of the high heat radiating substrate 14 to be connected to the control circuit 16 of the control substrate 17 on an outer side of the bus bar assembly 18.(3) Structure of Control Substrate 17The control circuits 16 of the control substrate 17 are disposed on both surfaces of the control substrate 17, and perform switching control of the respective power switching elements 13 of the high heat radiating substrate 14 based on an instruction from the outside. Moreover, the control circuit has a function of transmitting a driving state of the motor to the outside, and has a state in which a circuit component such as a microcomputer is connected via a printed line. In addition, in a peripheral portion of the control substrate 17, a connection portion 41 to be connected to the above-mentioned connector 39 of the high heat radiating substrate 14 is disposed.(4) Structure of Filter Mold Assembly 21The smoothing capacitor 19 is connected across the power source terminals and the ground terminals of the three-phase inverter, and receives high-frequency components of a switching current of the three-phase inverter circuit. The smoothing capacitor 19 is disposed in the filter mold package (the circuit substrate) 21, and the terminal plate 29 of the filter mold package 21 is connected to the conductive member 31 as described above and conductively connected to the power source harness via the conductive circuit substrate 32, the connection bus bar 33, the high-power connector 28, and others. The terminal plate 44 is connected to the electrode terminals 42 and 43 of the above-mentioned high heat radiating substrate 14.(5) Construction of Bus Latch Assembly 18The bus bar assembly 18 has five bus bars 46, 47, 48, 49, and 50 constituting the wires of the three-phase inverter circuit. The respective bus bars 46- 50 are disposed at positions of an outer side of the control substrate 17 and are integrally molded by insert molding an insulating hard resin. The bus bars 46-48 connect the respective electrode terminals 36, 37 and 38 of the high heat radiating substrate 14 to the corresponding terminal plates 26, and the bus bars 49 and 50 connect the electrode terminals 42 and 43 to the terminal plate 44 of the filter die assembly 21.(6) Assembly and Fixing of Inverter Switching Portion 3Next, a procedure for assembling the inverter switching section 3 will be described. First, as shown in FIG. 5, the bus bar assembly 18 is sandwiched between the high heat radiating substrate 14 on which the power switching elements 13 and others are mounted and the control substrate 17 on which the control circuit 16 is mounted, and in this state, the high heat radiating substrate 14, the bus bar assembly 18 and the control substrate 17 are laminated.In this laminated state, the respective electrode terminals 36, 37 and 38 and the electrode terminals 42 and 43 made of the screws are inserted from the other surface side of the high heat radiating substrate 14, and the terminals pass through the high heat radiating substrate 14 to be screwed into the bus bars 46-50 of the bus bar assembly 18, respectively. By this screwing, the respective electrode terminals 36, 37, 38, 42 and 43 are led to the circuit substrate of the high heat radiating substrate 14 and the bus bars 46-50.Further, the screws 51 and 52 are inserted from the surface side of the control substrate 17 and pass through the control substrate 17 to be screwed into the bus bar assembly 18. By this screwing, the high heat radiating substrate 14, the bus bar assembly 18 and the control substrate 17 are integrated. Subsequently, the smoothing capacitor 19 is disposed on the side of the high heat radiating substrate 14, and in this state, the terminal plate 44 of the filter mold assembly 21 is fixed to the side of a surface of the bus bar assembly 18 including the bus bars 49 and 50, and the screws 53 and 54 are inserted and screwed into the bus bars 49 and 50, whereby the filter mold assembly 21 is fixed to the bus bar assembly 18 via the screws. In this state, the terminal plate 44 leads to the respective electrode terminals 42 and 43 via the bus bars 49 and 50. Thus, the inverter switching portion 3 including the high heat radiating substrate 14, the control substrate 17, the bus bar assembly 18, and the filter die assembly 21 (the smoothing capacitor 19) is integrated (to form a sub-assembly).The inverter switching portion 3 integrated in this manner is accommodated in the inverter accommodating portion 8 of the motor housing 4 such that the high heat radiating substrate 14 is disposed on the partition wall 12 side. At this time, a filler material (grease or the like) for heat conduction is filled on the other surface of the high heat radiating substrate 14 at positions corresponding to the power switching elements 13, and the corresponding power switching elements 13 are closely contacted with the partition wall 12 via the filler material to establish a heat exchange relationship. In addition, the smoothing condenser 19 is closely contacted with the partition wall 12 to establish the heat exchange relationship.Subsequently, the inverter switching portion 3 is fixed to the motor housing 4 (housing 2) by using a plurality of bolts. Thereafter, the terminal plates 26 extend over the lead terminals 22, 23, and 24 and the bus bars 46, 47, and 48 and are conductively fixed and screwed thereto. Further, the terminal plate 29 of the filter die assembly 21 is fixed to the conductive part 31 (FIGS. 4 and 2 ) via screws 56 to conduct. Subsequently, the cover part 11 is finally inserted over the opening 9 of the inverter accommodating portion 8 by using a plurality of screws, and thus the opening 9 of the inverter accommodating portion 8 (FIG. 1 ) is openably closed.(7) Structure of the power switching element 13 and structure of its circumferential high-heat radiating substrate 14Next, the structure of the power switching element 13 and the structure of the high heat radiating substrate 14 around the power switching elements will be described based on FIGS. 6 to 10. On the high heat radiating substrate 14, a plurality of power switching elements are mounted as a circuit substrate of the electronic switching device (the inverter switching section 3) of the present invention. In this case, depending on the embodiment, two of the respective power switching elements 13 are arranged in parallel as illustrated in FIG. 6, so that electronic circuits are connected in parallel to each other to form each power switching element group 13G (FIG. 6 ). Then, in the respective power switching element groups 13G, three power switching element groups on the upper arm sides of the respective phases and three power switching element groups on the lower sides thereof are used.Moreover, in the present invention, each power switching element 13 is made of a non-conductive case member. That is, the power switching element 13 is, for example, a MOSFET. As illustrated in FIGS. 7 to 10, the power switching element includes a semiconductor chip 57, a drain terminal 58 connected to a back surface of the semiconductor chip 57 via solder 60, a plurality of source terminals 59, a gate terminal 61, and a plurality of wire members 62 including aluminum wires to connect the surface of the semiconductor chip 57 to the source terminals 59 and the gate terminal 61, respectively.In addition, the semiconductor chip 57 and the wire members 62 are molded of a resin 63, and the source terminals 59 and the gate terminal 61 are disposed and exposed on one side in a longitudinal direction of the resin 63 (one side in the longitudinal direction of the power switching element 13). The drain port 58 is protruded from the resin 63 toward the back side. In addition, the respective terminals 58, 59 and 61 are connected to and mounted on the terminal substrate of the high heat radiating substrate 14.In addition, in the high heat radiating substrate 14, in the vicinity of each power switching element group 13G, a pair of through holes 64 and 64 for inspection in the embodiment are disposed on both sides of the power switching element group 13G in the width direction thereof. In this case, the respective through holes 64 and 64 are formed to correspond to a region X 1 where the wire members 62 are arranged as illustrated in FIGS. 9 and 10. Each through hole 64 has an opening dimension so that a current probe can be inserted into the through hole.In the above configuration, when the characteristics of the power switching element group 13G (the power switching elements 13) mounted on the high heat radiating substrate 14 are measured, for example, during the evaluation in a development phase or during the substrate inspection in mass production, the measurement is performed with a current probe (generally referred to as a Rogowsky coil current probe) passing through this pair of through holes 64. Further, when the filling material for heat conduction is filled in the other surface of the high heat radiating substrate 14 to bring the power switching element 13 closely into contact with the partition wall 12 as in the embodiment, this filling material is optically confirmed from each through hole 64.Thus, in the high heat radiating substrate 14, the pair of through holes 64 and 64 for inspection are positioned in the vicinity of the power switching element group 13G and formed in the width direction of the power switching element group 13G. Consequently, a current of the power switching element group 13G mounted on the high heat radiating substrate 14 can be measured with a current probe passed through this pair of through holes.Consequently, when a plurality of power switching elements 13 composed of the non-conductive case members are arranged in parallel and connected in parallel to each other to form the power switching element group 13G, it is possible to examine the characteristics in actually switching the power switching element group 13G, for example, during the evaluation in the development phase or during the substrate inspection in mass production, and it is possible to accurately measure the characteristics during an original operation while achieving improvement in quality. Further, such effects can be achieved with a simple structure in which the through holes 64 are made and thus a high increase in production cost can be avoided.Specifically, the power switching element 13 includes the semiconductor chip 57 molded from the resin 63, the terminals 58, 59, and 61 exposed from the resin 63, and the wire members 62 molded from the resin 63 to connect the semiconductor chip 57 to the terminals 59 and 61, and the through holes 64 are formed to correspond to the region X 1 where the wire members 62 are arranged. Consequently, it is possible to more accurately measure a current flowing through the wire members with the current probe.Specifically, as in the embodiment, the inverter switching portion 3 of the inverter integrated electric compressor 1 including the motor housing 4 in which the motor is accommodated and the inverter switching portion 3 for supplying power to the motor is constituted of the electronic switching device of the present invention, the inverter switching portion 3 is fixed to the motor housing 4, and in this state, the power switching elements 13 are arranged in the heat exchange relationship with the motor housing 4 via the filler material for heat conduction. In this case, whether or not the filling material is sufficiently filled can be visually confirmed via the through holes 64. Consequently, it is possible to prevent in advance the disadvantage that severe defects such as smoke and burning occur due to cooling defects of the power switching elements 13 in the motor housing 4.Here, in the embodiment, two power switching elements 13 are arranged in parallel and connected in parallel to each other to form the power switching element group 13G. However, when three power switching elements (device units) 13 are used on the upper arm sides of the respective phases and three power switching elements on the lower arm sides thereof as shown in FIG. 11, a pair of through holes 64 in the width direction of the power switching element 13 may be disposed in the vicinity of the power switching element 13 mounted on the high heat radiating substrate 14 for examination. Also in this case, the respective through holes 64 and 64 are formed corresponding to the region X 1 where the wire members 62 are provided.Also according to such a configuration, it is possible to measure a current of the power switching element 13 mounted on the high heat radiating substrate 14 with the current probe passing through the pair of through holes 64 and 64. Even if the power switching element 13 is made of the non-conductive case member, it is possible to check the characteristics (current and voltage) in actually switching the power switching element 13, for example, during the evaluation in the development phase or in the substrate inspection of mass production. Consequently, it is possible to measure the characteristics during an original operation, thereby achieving improvement in quality. Further, a structure is also simple, and thus a high increase in production cost can be avoided.Note that in this embodiment, the pair of through holes 64 is formed in the vicinity of the power switching element group 13G (the power switching elements 13), but other pairs of through holes may be formed. In addition, in the embodiment, the wire members 62 are made of aluminum wires, but may be made of thin metal plates (e.g., copper).Further, in the embodiment, the filler for heat conduction is filled in the other surface of the high heat radiating substrate 14 to bring the power switching element 13 closely into contact with the partition wall 12, but a seat (fixed) for heat conduction may be disposed at a position corresponding to the power switching element 13 on the other surface of the high heat radiating substrate 14 to bring each power switching element 13 into close contact with the partition wall 12 via this seat for heat conduction and thus establish a heat exchange relationship. In this case as well, it can be visually confirmed whether or not the seat is sufficiently close in contact with the partition wall for heat exchange by using the through holes 64. Consequently, it is possible to prevent in advance the disadvantage that severe defects such as smoke and burning occur due to cooling defects of the power switching elements 13 in the motor housing 4.In addition, in this embodiment, the inverter switching portion 3 is fixed to the motor housing 4 by using screws, but the other surface of the high heat radiating substrate 14 may be coated with an adhesive and adhered and fixed to the motor housing 4. In this case, it can be confirmed whether or not the adhesive is sufficiently cured by the use of the through holes 64. Consequently, it is possible to prevent in advance the disadvantage that failures occur in circuit components due to mounting defects of the inverter switching portion 3 to the motor housing 4.Further, the shapes and structures of the inverter switching portion 3, the motor housing 4, and the power switching elements 13 described in the embodiment are not limited thereto, and it goes without saying that the shapes and structures may be changed variously without departing from the gist of the present invention. Moreover, the electronic switching device of the present invention is not limited to an inverter-integrated electric compressor of the embodiment, and is applicable to various electric apparatuses.LIST OF REFERENCE CHARACTERS1 Inverter integrated electric compressor 2 Housing 3 Inverter switching portion (an electronic switching device) 4 Motor housing 6 Compression mechanism housing 8 Inverter accommodating portion 12 Partition wall 13 Power switching element (a non-conductive housing component) 13G Power switching element group 14 High heat radiating substrate (a circuit substrate) 17 Control substrate 18 Bus bar assembly 19 Smoothing capacitor 21 Filter mold assembly 22- 24 Lead terminal 46- 50 Bus bar 57 Semiconductor chip 58 Drain terminal 59 Source terminal 61 Gate terminal 62 Wire member 63 Resin 64 Through hole

Claims

An electronic switching device comprising a lead-less case member mounted on a circuit substrate, wherein the lead-less case member is a power switching element, and at least one pair of through holes in a width direction of the power switching element for inspection is formed in the circuit substrate to be positioned in the vicinity of the power switching element.An electronic switching device comprising a lead-less case member mounted on a circuit substrate, wherein the lead-less case member is a power switching element, and on the circuit substrate, a plurality of power switching elements are arranged in parallel in the width direction thereof and connected to each other in parallel to form a power switching element group, and in the circuit substrate, at least one pair of through holes in a width direction of the power switching element group for inspection is formed to be positioned in the vicinity of the power switching element group.The electronic switching device according to claim 1 or 2, wherein the power switching element includes a semiconductor chip molded from a resin, terminals protruding from the resin, and wire members molded from the resin for connecting the semiconductor chip to the terminals, and the through holes are respectively formed in a region where the wire members are arranged.An inverter integrated electric compressor comprising a housing accommodating a motor and an inverter switching portion formed of the electronic switching device according to any one of claims 1 to 3 to supply power to the motor.The inverter integrated electric compressor according to claim 4, wherein the inverter switching portion is fixed to the housing, and in this state, the power switching element is disposed in a heat exchange relationship with the housing via a filler material for heat exchange.The inverter integrated electric compressor according to claim 4, wherein the inverter switching portion is fixed to the housing, and in this state, the power switching element is disposed in a heat exchange relationship with the housing via a seat for heat exchange.The inverter integrated electric compressor according to claim 4, wherein the inverter switching portion is fixed to the housing by fixing the circuit substrate to the housing with an adhesive.

Images