JP5370282B2 - Electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor-driven compressor capable of simplifying electric joining work when forming a drive circuit unit while securing cooling property of a power element. <P>SOLUTION: In an inverter circuit 20, a first substrate 21 with a power element 214 incorporated in an insulating base material 211 and a second substrate 22 with no element incorporated therein are layered, and the second substrate 22 is positioned and fixed to a housing 1. The first substrate 21 is arranged more on the housing side from the second substrate 22. An electrode 212a is provided to a first face 21a. The electrode 212a is electrically connected to the electrode 222 of the second substrate 22 to form an electrically connection part 20a. A second face 21b is brought into close contact with a fitting face 1c formed at a part in which sucked refrigerant is distributed out of the outer surface of the housing 1. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to an electric compressor having a motor driving circuit such as a compression mechanism that compresses refrigerant, an electric motor that drives the compression mechanism, and an inverter circuit that drives the electric motor.

  Conventionally, there is an electric compressor including a compression mechanism that sucks and compresses a refrigerant, an electric motor that drives the compression mechanism, and a drive circuit unit that drives the motor. Then, in order to cool the power element of the drive circuit section that generates a large amount of heat during driving, the main body of the power element is brought into close contact with the outer peripheral surface of the housing via a base plate or the like, and protrudes from the main body of the power element toward the anti-housing direction. There is known an electric compressor in which the lead terminal of the power element is electrically connected to the circuit board of the drive circuit unit (see, for example, Patent Document 1).

JP 2004-190547 A

  However, in the above-described conventional electric compressor, when the drive circuit unit is formed, the circuit element is mounted on the surface of the circuit board by, for example, reflow soldering, and then the lead terminal of the power element is connected to the circuit board by, for example, flow soldering. There is a problem that the electrical connection work of the drive circuit section is complicated.

  The present invention has been made in view of the above points, and provides an electric compressor capable of simplifying an electrical joining operation when forming a drive circuit portion while ensuring cooling performance of a power element. For the purpose.

In order to achieve the above object, in the invention described in claim 1,
A compression mechanism for sucking and compressing the refrigerant;
An electric motor that drives the compression mechanism;
A drive circuit unit for driving the motor;
A housing that houses the compression mechanism and the motor, and through which the refrigerant sucked by the compression mechanism is circulated.
The drive circuit section
A first substrate having a power element built in an insulating base material for controlling power supplied to the motor, and a circuit element not mounted in the insulating base material and mounted on the surface by soldering . 2 substrates, the first substrate and the second substrate are stacked and arranged,
The first substrate is disposed closer to the housing than the second substrate, and an electrode formed as a land is provided on the first surface, which is one of both surfaces, and this electrode is disposed on the housing side of the second substrate . The electrodes formed as lands on the surface are electrically connected by soldering to form an electrical connection portion between the first substrate and the second substrate, and the other surface, the second surface is the outer surface of the housing It is characterized in that it is in contact with a mounting surface formed in a portion through which the suction refrigerant flows.

  According to this, when forming the drive circuit portion, when mounting the circuit element on the surface of the second substrate, the first substrate is mounted on the second substrate in the same manner as the circuit element. It is possible to form an electrical connection with the second substrate. In addition, the first substrate in which the power element is built in the insulating base can be brought into contact with the mounting surface of the housing, and can be cooled with the sucked refrigerant flowing in the housing. Therefore, it is possible to simplify the electrical joining operation when forming the drive circuit portion while ensuring the cooling performance of the power element.

In the first aspect of the invention, the second substrate has a fixing portion for positioning and fixing the second substrate with respect to the housing, and the other portion is provided between the fixing portion and the electrical connection portion. It is characterized in that a flexible part that is more easily bent is formed. When the first substrate and the second substrate are stacked and the second substrate is positioned and fixed with respect to the housing by the fixing portion, the distance between the fixing portion and the mounting surface of the housing, the variation in the substrate thickness, etc. The first substrate and the second substrate cannot be formed in a good contact state between the second surface of the first substrate and the mounting surface of the housing, or the pressing force of the first substrate on the mounting surface of the housing becomes too large. Stress concentration may occur at the electrical connection with the. However, according to the invention of this claim, the flexible portion formed between the fixed portion of the second substrate and the electrical connection portion is bent to provide a good contact state between the first substrate and the housing. It is possible to alleviate the stress concentration generated in the electrical connection portion between the first substrate and the second substrate while being formed.

According to a second aspect of the present invention, the flexible portion of the second substrate is formed in an annular shape surrounding the electrical connection portion. According to this, the stress concentration generated in the electrical connection portion between the first substrate and the second substrate can be reliably reduced while forming a good contact state between the first substrate and the housing.

According to a third aspect of the present invention, there is provided an elastic member disposed on the side opposite to the housing of the second substrate, and the elastic member presses the second substrate toward the housing. According to this, the elastic member can press the first substrate toward the housing via the second substrate, and can satisfactorily contact the second surface of the first substrate with the mounting surface of the housing.

According to a fourth aspect of the present invention, the elastic member presses a region of the second substrate where the electrical connection portion is formed. According to this, even if the elastic member presses the first substrate toward the housing via the second substrate, stress concentration is prevented from occurring at the electrical connection portion between the first substrate and the second substrate. Can do.

According to a fifth aspect of the present invention, an adhesive is interposed between the first substrate and the second substrate except for the electrical connection portion, and the first substrate and the second substrate are bonded. It is characterized by being. According to this, the periphery of the electrical connection portion between the first substrate and the second substrate is reinforced with the adhesive, and it is ensured that stress concentration occurs in the electrical connection portion between the first substrate and the second substrate. Can be prevented.

It is a front view which shows the external shape of the electric compressor in one Embodiment to which this invention is applied. It is the sectional view on the AA line in FIG. It is sectional drawing which shows the internal structure of an electric compressor. It is sectional drawing which shows schematic structure of the arrangement | positioning site | part of the inverter circuit 20 which is a drive circuit part. 3 is a top view of the inverter circuit 20. FIG. 3 is an enlarged cross-sectional view of a main part of an inverter circuit 20. FIG. It is a top view of the inverter circuit 20 in other embodiment. It is sectional drawing which shows schematic structure of the arrangement | positioning site | part of the inverter circuit 20 in other embodiment. It is a top view of the inverter circuit 20 in other embodiment. It is sectional drawing which shows schematic structure of the arrangement | positioning site | part of the inverter circuit 20 in other embodiment. It is sectional drawing which shows schematic structure of the arrangement | positioning site | part of the inverter circuit 20 in other embodiment. It is sectional drawing which shows schematic structure of the arrangement | positioning site | part of the inverter circuit 20 in other embodiment. It is sectional drawing which shows schematic structure of the arrangement | positioning site | part of the inverter circuit 20 in other embodiment. It is sectional drawing which shows schematic structure of the arrangement | positioning site | part of the inverter circuit 20 in other embodiment.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those described previously. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination is not particularly troublesome.

  FIG. 1 is a front view showing an outer shape of an electric compressor in an embodiment to which the present invention is applied. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is a cross-sectional view showing the internal structure of the electric compressor.

  The electric compressor 100 shown in FIG. 1 is arrange | positioned, for example in the engine room of a motor vehicle. The electric compressor 100 constitutes a refrigeration cycle device for a vehicle air conditioner together with a condenser, a decompressor, and an evaporator. The electric compressor 100 includes a housing 1.

  The housing 1 is made of a metal such as an aluminum material or an aluminum alloy material having high heat conductivity, and is formed in a substantially cylindrical shape. The housing 1 is provided with a refrigerant inlet 1a and a refrigerant outlet 1b.

  The refrigerant suction port 1 a is disposed on the one side in the axial direction in the housing 1. The refrigerant from the refrigerant outlet of the evaporator flows into the refrigerant inlet 1a. The refrigerant discharge port 1 b is disposed on the other side in the axial direction in the housing 1. The refrigerant discharge port 1b discharges the refrigerant toward the refrigerant inlet of the condenser.

  Legs 2 are provided on the upper side of the housing 1. Legs 3 and 4 are provided on the lower side of the housing 1. The leg portions 2, 3, 4 are each provided with a through-hole through which the bolt 5 passes. Each bolt 5 fixes the housing 1 to the side wall of the engine while passing through the through holes of the leg portions 2, 3, 4.

  2 and 3, the electric compressor 100 includes a motor unit 10 (corresponding to a motor), an inverter circuit 20 (corresponding to a drive circuit unit), a compression mechanism 30, and an inverter cover 40 (corresponding to a cover member). Etc.

  The motor unit 10 is a three-phase synchronous motor, and includes a rotating shaft 12, a rotor 13, a stator core 14, and a stator coil 15.

  The rotating shaft 12 is disposed in the housing 1. The rotating shaft 12 has an axial direction that coincides with the axial direction of the housing 1. The rotating shaft 12 is rotatably supported by bearings 12a and 12b. The rotating shaft 12 transmits the rotational driving force received from the rotor 13 to the compression mechanism 30. The bearings 12 a and 12 b are supported by the housing 1.

  The rotor 13 is, for example, a permanent magnet embedded in a cylindrical shape, and is fixed to the rotating shaft 12. The rotor 13 rotates together with the rotating shaft 12 based on the rotating magnetic field generated from the stator core 14.

  The stator core 14 is disposed on the outer peripheral side in the radial direction with respect to the rotor 13 (rotating shaft 12) in the housing 1. The stator core 14 is formed in a cylindrical shape whose axial direction coincides with the axial direction of the rotary shaft 12. The stator core 14 forms a gap with the rotor 13. The gap constitutes a refrigerant flow path 17 through which the refrigerant flows in parallel to the axial direction of the rotating shaft 12.

  The stator core 14 is made of a magnetic material and is supported from the inner peripheral surface of the housing 1. The stator coil 15 is wound around the stator core 14. The stator coil 15 generates a rotating magnetic field as will be described later.

  The compression mechanism 30 is disposed on the other side in the axial direction with respect to the motor unit 10. The compression mechanism 30 is a scroll type compressor composed of a fixed scroll and a movable scroll. The compression mechanism 30 turns the movable scroll by a rotational driving force from the rotary shaft 12 of the motor unit 10 to suck, compress, and discharge the refrigerant.

  The inverter circuit 20 is mounted on the mounting surface 1 c of the housing 1. The mounting surface 1c is formed on the outer peripheral portion of the housing 1 (that is, on the outer peripheral side in the radial direction of the rotating shaft 12). In the present embodiment, the mounting surface 1 c is located above the outer peripheral portion of the housing 1.

  The inverter circuit 20 is composed of a semiconductor element or the like, and constitutes a drive circuit that generates a three-phase voltage that drives the motor unit 10. The inverter cover 40 is formed so as to cover the inverter circuit 20. The inverter cover 40 is fastened to the housing 1 by a plurality of screws 42 (see FIG. 4).

  As shown in FIG. 2, the outer peripheral wall of the stator core 14 is provided with recesses 14a, 14b, 14c, and 14d. The recess 14 a is formed so as to be recessed in the radial center of the rotary shaft 12 and to extend in parallel to the stator core 14 in the axial direction. Similarly, the recesses 14 b, 14 c, and 14 d are formed so as to be recessed in the radial center of the rotating shaft 12 and extend in parallel to the stator core 14 in the axial direction.

  The recesses 14a, 14b, 14c, and 14d are arranged so as to be displaced at the same interval in the circumferential direction around the rotation shaft 12. The recess 14a is arranged on the inverter circuit 20 side. The recess 14 a forms a first refrigerant flow path 60 between the inner peripheral surface of the housing 1. The recesses 14b, 14c, and 14d constitute second refrigerant flow paths 61, 62, and 63, respectively, with the inner peripheral surface of the housing 1.

  Here, a heat insulating film 80 is provided on the side of the inverter circuit 20 in the recess 14a (on the inner surface of the recess 14a). FIG. 2 schematically shows a heat insulating film 80 having a predetermined thickness. Actually, the heat insulating film 80 is formed in a thin film shape.

  The heat insulating film 80 is formed so as to cover the bottom portion 140 and the side portions 141a and 141b of the concave portion 14a. That is, the heat insulating film 80 is formed in a substantially U-shape when viewed from the axial direction. The heat insulating film 80 prevents heat transfer between the refrigerant and the stator core 14.

  The heat insulating film 80 is made of a material that is highly resistant to refrigerant and lubricating oil (compressor oil) and can withstand high temperatures and high pressures. For example, bismuth (metal), ceramics (inorganic polymer), polyimide (organic inorganic high Molecule) and the like. As the heat insulating film 80, it is particularly preferable to use polyimide having excellent heat resistance.

  The operation of the electric compressor 100 having the above-described configuration will be briefly described. First, the inverter circuit 20 is turned on, and a three-phase drive current is passed through the stator coil 15 of the motor unit 10. Along with this, a rotating magnetic field is generated from the stator core 14, and thus a rotational force is generated on the rotor 13. Then, the rotor 13 rotates with the rotating shaft 12. Therefore, the compression mechanism 30 turns by the rotational driving force from the rotating shaft 12 and sucks the refrigerant.

  At this time, the suction refrigerant from the evaporator side flows into the refrigerant suction port 1 a side of the housing 1. Then, the sucked refrigerant passes through the refrigerant flow paths 17, 60, 61, 62, 63 and flows to the compression mechanism 30 side. The suction refrigerant is compressed by the compression mechanism 30 and discharged from the refrigerant discharge port 1b to the condenser side.

  On the other hand, the inverter circuit 20 generates heat along with its operation. This heat is transmitted to the refrigerant in the refrigerant flow path 60 through the meat part 1n of the housing 1 (see FIGS. 2 and 3).

  At this time, the stator coil 15 generates heat as the three-phase drive current is applied, but the heat insulation film 80 prevents heat transfer between the refrigerant in the refrigerant flow path 60 and the stator core 14. Therefore, the inverter circuit 20 is cooled by the refrigerant in the refrigerant flow path 60.

  Further, the heat generated from the stator coil 15 is transmitted to the refrigerant in the refrigerant flow paths 17 and 61 to 63 through the stator core 14. Thereby, the stator core 14 and the stator coil 15 can be cooled by the refrigerant in the refrigerant flow paths 17 and 61 to 63.

  Next, the configuration of the drive circuit unit that drives the motor will be described with reference to FIGS. 4 is a cross-sectional view showing a schematic configuration of an arrangement portion of the inverter circuit 20 which is a drive circuit unit, and FIG. 5 is a top view of the inverter circuit 20 (viewed from above in FIG. 4). 6 is an enlarged cross-sectional view of a main part of the inverter circuit 20. 5 and FIG. 6, illustration of circuit elements and the like mounted on the surface of the second substrate 22 is omitted.

  As shown in FIG. 4, the inverter cover 40 is attached to the housing 1 with screws 42 so as to cover the inverter circuit 20, and the inverter circuit 20 is attached to the inverter cover 40 with a plurality of screws 223. In other words, the inverter circuit 20 is housed in a casing having the mounting surface 1c of the housing 1 as a bottom surface portion and the inverter cover 40 serving as a side surface portion and a ceiling surface portion. A seal member 41 is disposed between the inverter cover 40 and the housing 1 to block the accommodation space of the inverter circuit 20 from the external space.

  The inverter circuit 20 includes a first substrate 21 and a second substrate 22, and the first substrate 21 and the second substrate 22 are electrical connection portions 20a (refer to FIG. 6) including electrodes 222 and electrodes 212a. It is connected. The first substrate 21 is a circuit board with a built-in element that incorporates a power element 214 and the like.

  On the other hand, the second substrate 22 is a non-element built-in circuit board in which no element is built in the insulating base material, and is composed of a so-called general-purpose printed circuit board such as a glass epoxy board, and various circuit elements are provided on the surface of the insulating base material. Has been implemented. The second substrate 22 is mounted with large components such as a connector 221 having a connection terminal with the outside and a power supply filter.

  The first substrate 21 and the second substrate 22 are laminated and the first substrate 21 is disposed closer to the housing 1 than the second substrate 22. The second substrate 22 is fixed to the inverter cover 40 with screws 223, and the inverter circuit 20 is positioned and fixed with respect to the housing 1. A portion of the second substrate 22 that is fixed to the inverter cover 40 with a screw 223 is a fixing portion 223 a that positions and fixes the second substrate 22 with respect to the housing 1 via the inverter cover 40.

  As shown in FIG. 6, a part of the conductor pattern 212 is formed on the first substrate 21 on the outer peripheral edge portion of the first surface 21a, which is one of the two surfaces (the upper surface in the drawing, the surface opposite to the housing). For example, an electrode 212a formed as a land is provided. This electrode 212a is electrically connected to an electrode 222 formed as a land, for example, on the lower surface (surface on the housing side) of the second substrate 22, and an electrical connection portion 20a between the first substrate 21 and the second substrate 22 is achieved. Is forming.

  Between the first substrate 21 and the second substrate 22 in the peripheral portion of the electrical connection portion 20a (that is, in a portion excluding the electrical connection portion 20a between the first substrate 21 and the second substrate 22). 1) An underfill 20b, which is an adhesive, is interposed between the first substrate 21 and the second substrate 22 to reinforce the periphery of the electrical connection portion 20a.

  And the 2nd surface 21b which is the other surface (illustration lower surface, housing side surface) among both surfaces of the 1st board | substrate 21 is a mounting surface formed in the site | part through which the suction | inhalation refrigerant | coolant distribute | circulates among the outer surfaces of the housing 1. It adheres closely to 1c.

  Specifically, an insulating heat radiating sheet 24 (corresponding to an insulating sheet member) is interposed between the second surface 21b of the first substrate 21 and the mounting surface 1c of the housing 1, and the insulating heat radiating sheet is provided. The first substrate 21 and the housing 1 are in close contact with each other through 24. The insulating heat dissipation sheet 24 is made of, for example, a silicone material filled with a ceramic filler.

  As shown also in FIG. 5, the second substrate 22 has a region where the first substrate 21 is stacked (the first substrate 21 is disposed inside the outer periphery of the second substrate 22 when viewed from the substrate stacking direction). Of the first substrate 21 and the second substrate 22 except for the electrical connection portion 20a (specifically, a region inside the electrical connection portion 20a), for example, a rectangular opening. 22a is formed. In this example, the housing-side surface of the edge portion along the opening 22 a of the second substrate 22 is an electrical connection portion 20 a with the first substrate 21.

  Therefore, the first surface 21a of the first substrate 21 is exposed in the opening 22a of the second substrate 22 in the region inside the electrical connection portion 20a, and the exposed region in the opening of the first surface 21a includes: A circuit element 215 a such as a snubber component that constitutes a circuit is mounted on the first substrate 22.

  As shown in FIGS. 4 and 5, grooves 217 a and 217 b are formed on the upper surface of the second substrate 22. The groove portion 217 a extends in a substantially rectangular ring shape so as to surround the electrical connection portion 20 a (specifically, a portion slightly outward from the outer periphery of the first substrate 21), and the groove portion 217 b includes a plurality of the second substrate 22. Are extended in a substantially arc shape so as to surround each of the fixed portions 223a. The portion where the groove portions 217a and 217b are formed on the second substrate 22 has a thinner substrate thickness than the other portions, and bends more than the other portions between the fixing portion 223a and the electrical connection portion 20a. An easy-to-use flexible part is formed.

  The groove portions 217a and 217b may be formed when the second substrate 22 is formed, or may be formed by removal processing such as cutting after the second substrate 22 is formed.

  For example, a rubber packing 43 is disposed on the upper surface side (the opposite housing side) of the second substrate 22. The packing 43 is formed in an annular shape corresponding to a region where the edge of the opening 22a of the second substrate 22 and the outer peripheral edge of the second substrate 21 overlap, that is, the region where the electrical connection portion 20a is formed.

  On the ceiling surface of the inverter cover 40, an annular projecting portion 40a projecting downward is formed. The protruding portion 40 a is formed in an annular shape corresponding to the shape of the packing 43, and the packing 43 is compressed between the protruding portion 40 a and the second substrate 22 in the illustrated vertical direction. Thereby, the packing 43 presses the region where the electrical connection portion 20a is formed on the lower surface side of the second substrate 22 in the housing direction. The packing 43 corresponds to an elastic member that is disposed on the side opposite to the housing of the second substrate 22 and presses the second substrate 22 toward the housing 1.

  The pressed portion by the packing 43 is preferably a region of the second substrate 22 where the electrical connection portion 20a is formed on the lower surface side, but the load applied to the electrical connection portion 20a does not cause a problem. For example, it may be a region outside the electrical connection portion 20a.

  Here, the configuration of the first substrate 21 will be described. As shown in FIG. 6, the first substrate 21 includes an insulating base material 211 made of a thermoplastic resin, a power element 214 disposed inside the insulating base material 211, and other members disposed inside the insulating base material 211. Circuit elements 215 and other electronic components such as other circuit elements 215a (for example, passive elements such as resistors) disposed on the surface, and power elements 214 and other circuit elements formed inside or on the surface of the insulating substrate 211 215 and 215a are provided with a conductor pattern 212 and an interlayer connection via 213 as wiring portions that are electrically connected.

  In other words, the first substrate 21 has an interlayer connection in which conductor patterns 212 are arranged in multiple layers on the surface and inside of an insulating base material 211 made of a thermoplastic resin, and a part of the conductor patterns 212 of different layers is an interlayer connection portion. The power element 214 is electrically connected between the vias 213 (for example, a conductive paste can be used) and electrically connected to the conductor pattern 212 and the interlayer connection portion 213 in the insulating base material 211. It is a multilayer substrate on which electronic parts such as are arranged.

  In addition, the first substrate 21 includes a heat dissipation chip 216 made of, for example, copper, which is a heat transfer member embedded in the insulating base material 211. The heat dissipating chip 216 is embedded in a portion of the insulating base material 211 that is closer to the mounting surface 1c side of the housing 1 than the power element 214 (lower side in FIG. 6). The lower surface of the heat dissipating chip 216 is exposed from the insulating base material 211, and the lower surface of the heat dissipating chip 216 and the lower surface of the insulating base material 211 are in the same plane.

  The insulating base material 211 of the first substrate 21 is configured by, for example, laminating a plurality of thermoplastic resin films (base material films) and bonding (welding) them to each other. In addition, as a thermoplastic resin used for the resin film, for example, polyether ether ketone (PEEK), polyether imide (PEI), a mixture of polyether ether ketone and polyether imide, or a liquid crystal polymer may be employed. Can do.

  The first substrate 21 has a conductive pattern 212 made of, for example, a metal foil as a part of the wiring portion on the surface, and a conductor (for example, a conductive paste) is embedded in a via hole having the conductive pattern 212 as a bottom. Penetration depending on the size of the thermoplastic resin film (base film) having the interlayer connection via 213 as a part of the wiring part, the built-in electronic component such as the power element 214 and the built-in component such as the heat radiation chip 216 A plurality of layers of thermoplastic resin films (base film) having holes are laminated and bonded (welded) to each other.

  The conductor pattern 212 is preferably thicker in a so-called power system (for example, a motor current system) in which a relatively large current flows than in a non-power system (for example, a signal transmission system). When the power-type conductor pattern 212 is arranged in the same layer as the non-power-type conductor pattern 212, for example, a copper metal plate member can be used as the power-type conductor pattern 212. When the non-power conductive pattern 212 is disposed in a different layer, the power conductive pattern 212 can be formed of a metal foil or metal plate member that is thicker than the non-power conductive pattern 212.

  The first substrate 21 can be manufactured as follows. A plurality of thermoplastic resin films as described above are laminated with the power element 214, the circuit element 215, and the like disposed therein. And it pressurizes from both sides in the lamination direction, heating this laminated body. For example, pressurization is performed for 10 to 20 minutes at a pressure of 1 to 10 MPa under an atmospheric temperature of 250 to 350 ° C. Thus, the 1st board | substrate 21 can be manufactured by thermocompression bonding collectively.

  Although an example in which a plurality of thermoplastic resin films are used as the insulating base material 211 of the first substrate 21 has been described, the insulating base material 211 only needs to contain at least a thermoplastic resin, for example, thermoplastic. A base film containing a resin and a base film containing a thermosetting resin are laminated together (for example, alternately or so that the base films containing a thermosetting resin are not continuously laminated). You may make it employ | adopt. In this example, a base film containing a thermoplastic resin functions as an adhesive layer.

  The thermoplastic resin is preferably disposed around a built-in element such as the power element 214 built in the insulating base material 211. It is preferable to dispose the thermoplastic resin in at least a part of the portion in contact with the built-in element, and it is more preferable to dispose the thermoplastic resin over the entire area (entire surface) surrounding the built-in element. When a thermoplastic resin is disposed in a portion in contact with the built-in element, the built-in elements such as the power element 214 are sealed in the insulating base material 211 when the insulating base material 211 is formed by heating and pressing a plurality of laminated resin films. It is easy to stop (the entire area except the electrical connection portion on the outer surface of the built-in element is in close contact with the insulating base material).

  As is apparent from FIG. 6, the first substrate 21 is formed with a through hole 211 a that penetrates the insulating base material 211 in the thickness direction (vertical direction in the drawing) in the vicinity of the left side end portion in the drawing.

  The heat dissipating chip 216 is disposed so as to include a part or the whole of the projection region of the power element 214 in the thickness direction (the vertical direction in the drawing) of the insulating base material 211, and extends greatly to the left side in the drawing. . The heat radiation chip 216 extends to a region including a portion where the through hole 211a of the insulating base material 211 is formed. A through hole 216 a is formed on the same axis in the heat radiation chip 216 in correspondence with the through hole 211 a of the insulating base material 211.

  In a portion of the housing 1 where the mounting surface 1c is formed, a through terminal 16 extending from the stator coil 15 of the motor unit 10 (not shown in FIG. 6) and penetrating the housing 1 protrudes. The portion protruding outward is disposed in the through hole 211 a of the insulating base material 211. The through terminal 16 is a so-called hermetic terminal in which a portion penetrating the housing 1 is hermetically sealed with, for example, a glass material between the housing 1 and the housing 1.

  The through terminal 16 is electrically connected to the heat radiation chip 216 of the first substrate 21 by, for example, pressure contact. The inner diameter of the through hole 216a (and the inner diameter of the through hole 211a if necessary) is slightly smaller than the outer diameter of the through terminal 16, and the through terminal 16 is press-fitted into the through hole 216a to form the electrical connection configuration. can do. The heat dissipating chip 216 is electrically connected to the power element 214 by contacting the conductor pattern 212 or the like, and is connected to the through terminal 16 of the heat dissipating chip 216 (the through hole 216a portion of the heat dissipating chip 216). However, this is an output unit that outputs supply power from the first substrate 21 to the motor unit 10.

  The through terminal 16 may be electrically connected only to the heat dissipation chip 216, but may be connected to the conductor pattern 212 or the like having the same potential as the heat dissipation chip 216.

  Further, by adopting a terminal structure that can be elastically deformed in the radially inward direction to the through terminal 16, electrical connection may be performed by pressure contact between the through terminal 16 and the output portion of the first substrate 21. The outer diameter is slightly smaller than the inner diameters of the through-holes 216a and 211a, and conductive intermediate members that can be elastically deformed radially inward are disposed around the through-terminals 16 so that the outputs of the through-terminals 16 and the first substrate 21 can be obtained. Electrical connection may be made by pressure contact with the part via a conductive interposition member.

  Here, a method for manufacturing the inverter circuit 20 and a method for mounting the inverter circuit 20 to the housing 1 will be briefly described.

  As described above, when the first substrate 21 in which the power element 214 and the circuit element 215 are built is manufactured, first, the circuit element and the first substrate 21 are mounted on the surface of the second substrate 22. The first substrate 21 is also handled as one of the circuit elements, and is disposed on the surface of the second substrate 22 using, for example, the same mounter. At this time, the circuit element 215 a is also mounted on the first surface 21 a of the first substrate 21.

  Next, the circuit element mounted on the surface of the second substrate 22 and the first substrate 21 are mounted by reflow soldering. At the same time, the circuit element 215a mounted on the first surface 21a of the first substrate 21 is also mounted by reflow soldering. Implement.

  When the inverter circuit 20 is manufactured in this way, the inverter circuit 20 is attached to the inverter cover 40. For example, the ceiling surface of the inverter cover 40 is in a downward position, the packing 43 is attached to the tip of the protruding portion 40 a, the inverter circuit 20 is further attached from above, and the second substrate 22 of the inverter circuit 20 is attached by screws 223. Are fixed to the inverter cover 40.

  At this time, the inverter circuit 20 is pushed by the packing 43 and bent so as to protrude slightly upward, and the packing 43 is slightly compressed between the protruding portion 40 a and the second substrate 22. Specifically, the flexible part provided with the grooves 217a and 217b of the second substrate 22 is bent, so that the inverter circuit 20 is pushed by the packing 43 and slightly protrudes upward. Almost no stress is applied to the electrical connection portion 20a with the second substrate 22 (stress concentration does not occur).

  When the inverter circuit 20 is thus mounted on the inverter cover 40, the assembly of the inverter circuit 20 and the inverter cover 40 is mounted on the housing 1. Specifically, the inverter cover 40 is fixed to the housing 1 with screws 42. Accordingly, the second surface 21 b of the first substrate 21 of the inverter circuit 20 is in close contact with the mounting surface 1 c of the housing 1.

  Before the assembly of the inverter circuit 20 and the inverter cover 40 is mounted on the housing 1, the inverter circuit 20 is slightly bent and protrudes in the direction of the housing. However, the assembly of the inverter circuit 20 and the inverter cover 40 is advanced by screwing. After the solid body approaches the housing 1 and the second surface 21b of the first substrate 21 comes into contact with the mounting surface 1c of the housing 1, the protruding amount of the inverter circuit 20 decreases and the compression amount of the packing 43 increases. A tight contact state between the second surface 21b of the first substrate 21 and the mounting surface 1c of the housing 1 is ensured. At this time, electrical connection between the through terminal 16 and the output portion of the first substrate 21 is also performed.

  Thus, when the mounting of the inverter circuit 20 to the housing 1 is completed, the inverter circuit 20 may remain bent due to the dimensional variation of each component (mainly the dimensional variation in the substrate thickness direction). . Also in this case, the flexible portion provided with the grooves 217a and 217b of the second substrate 22 is bent so that no stress is applied to the electrical connection portion 20a between the first substrate 21 and the second substrate 22. It has become.

  According to the above-described configuration, the inverter circuit 20 includes the first substrate 21 that is an element-embedded substrate in which the power element 214 is embedded in the insulating base material 211 and the second substrate 22 that is a non-element-embedded substrate. Thus, the second substrate 22 is positioned and fixed with respect to the housing 1. The first substrate 21 is disposed closer to the housing than the second substrate 22, and an electrode 212 a is provided on the first surface 21 a, and the electrode 212 a is electrically connected to the electrode 222 of the second substrate 22. The second surface 21b is in close contact with the mounting surface 1c formed in the portion of the outer surface of the housing 1 through which the suction refrigerant flows.

  Therefore, when the inverter circuit 20 is manufactured, when the circuit element is mounted on the surface of the second substrate 22, the first substrate 21 is mounted on the second substrate 22 in the same manner as the circuit element. An electrical connection portion 20 a between 21 and the second substrate 22 can be formed. Further, the first substrate 21 in which the power element 214 is built in the insulating base material 211 can be brought into close contact with the mounting surface 1 c of the housing 1, and can be cooled with the suction refrigerant flowing in the housing 1. In this way, it is possible to simplify the electrical joining operation when manufacturing the inverter circuit 20 while ensuring the cooling performance of the power element 214.

  In addition, an opening 22a is formed in the second substrate 22 in a region excluding the electrical connection portion 20a in the region where the first substrate 21 is stacked, and the first substrate 21 in the first substrate 21 is formed in the opening 22a. A circuit element 215a is mounted on the surface 21a. Thus, by arranging the power element 214 and the circuit elements 215 and 215a in a so-called three-dimensional arrangement, the mounting density of the first substrate 21 can be improved and the wiring length can be made relatively short. Accordingly, the wiring inductance when forming a closed loop circuit including the built-in power element 214 and the circuit element 215a mounted on the first surface 21a can be reduced, and the surge voltage generated during the switching operation of the power element 214 can be reduced. Thus, generation of noise can be suppressed and loss can be reduced.

  In addition, a packing 43 that is an elastic member interposed between the inverter cover 40 and the second substrate 22 is provided, and the packing 43 presses the second substrate 22 toward the housing 1. ing. Therefore, the packing 43 can press the first substrate 21 toward the housing 1 via the second substrate 22, and the second surface 21 b of the first substrate 21 can be securely adhered to the mounting surface 1 c of the housing 1.

  Further, the packing 43 presses a region where the electrical connection portion 20 a is formed on the lower surface side of the upper surface of the second substrate 22. Therefore, even if the packing 43 presses the first substrate 21 toward the housing 1 through the second substrate 22, and the second surface 21 b of the first substrate 21 is brought into close contact with the mounting surface 1 c of the housing 1, the first substrate It is possible to prevent stress concentration from occurring in the electrical connection portion 20a between the first substrate 21 and the second substrate 22.

  Further, an underfill 20b, which is an adhesive, is interposed between the first substrate 21 and the second substrate 22 except for the electrical connection portion 20a, thereby bonding the first substrate 21 and the second substrate 22 together. doing. Accordingly, the periphery of the electrical connection portion 20a between the first substrate 21 and the second substrate 22 is reinforced with the underfill 20b, and stress concentration occurs in the electrical connection portion 20a between the first substrate 21 and the second substrate 22. This can be surely prevented.

  Further, the inverter circuit 20 that is a drive circuit unit includes a first substrate 21 in which a power element 214 that controls supply power supplied to the motor unit 10 is incorporated in an insulating base material 211. It is attached to the attachment surface 1 c of the housing 1 and is cooled by the sucked refrigerant flowing through the housing 1. Therefore, it is not necessary to dispose the main body portion of the power element 214 in a layer different from the circuit board and cool it by pressing it against the housing. In this way, the size of the inverter circuit 20 can be reduced while ensuring the cooling performance of the power element 214.

  Further, when the power element main body is disposed in a layer different from the circuit board and pressed against the housing to cool the power element, it is difficult to transfer the heat of the circuit board to the housing. It is possible to dissipate heat from the first substrate 21 to the housing 1, and heat dissipation can be improved.

  When the power element body is arranged in a layer different from the circuit board and is pressed against the housing to cool the power element, an inner connector is generally used for the electrical connection between the through terminal and the circuit board. It is done.

  This is due to the following reasons. When a glass material is used for the hermetic seal portion of the through terminal, a material whose linear expansion coefficient approximates that of the glass material needs to be used as a constituent material of the through terminal. Further, the circuit board is secured to the housing via a fixing member made of, for example, an aluminum material while ensuring a spatial distance from the housing in order to ensure space insulation. However, this fixing member has a larger coefficient of linear expansion than the penetrating terminal, and the electrical connection portion between the penetrating terminal and the circuit board is far away from the hermetic seal portion due to the spatial distance. Accordingly, a connector having a floating structure is used in order to suppress the occurrence of a large stress in the electrical connection portion between the through terminal and the circuit board under an environment where the temperature change is large.

  However, according to the configuration of the present embodiment, as shown in FIG. 4, the first substrate 21 can be brought into contact with the mounting surface 1 c of the housing 1 via the insulating heat-dissipating sheet 24. The spatial distance with the first substrate 21 can be reduced. Thereby, since it can suppress that big stress generate | occur | produces in the electrical connection part of the penetration terminal 16 and the 1st board | substrate 21 in an environment with a large temperature change, an inner connector can be abolished.

  In addition, the first substrate 21 has a heat radiation chip 216 in the insulating base material 211 at a portion closer to the attachment surface 1 c than the power element 214. Therefore, the heat generated by the power element 214 can be easily transmitted to the housing 1 via the heat radiation chip 216, and the cooling performance of the power element 214 can be improved.

  Further, the heat dissipation chip 216 is electrically connected to the power element 214, and the heat dissipation chip 216 and the through terminal 16 are directly connected. Therefore, the conduction path of the supply current to the motor unit 10 having a relatively large current can be made compact (no need to use a wide conductor pattern or the like), and the size of the first substrate 21 can be further reduced. Can do. In the present embodiment, the conductive pattern 212 in contact with the heat radiation chip 216 may be a metal foil having the same thickness as that of the non-power system even if it is a power system.

  Further, the heat radiation chip 216 exposed on the lower surface of the first substrate 21 is used as a power conduction path. An insulating heat radiation sheet 24 is interposed between the first substrate 21 and the mounting surface 1 c of the housing 1. Therefore, a short circuit between the heat radiation chip 216 and the housing 1 can be prevented.

  The inverter circuit 20 is configured by electrically connecting a first substrate 21 that is a circuit board with a built-in element and a first substrate 22 that is a circuit board with a non-element built-in. Therefore, the inverter circuit 20 can be configured at a relatively low cost by using a part of the substrate constituting the inverter circuit 20 as a relatively inexpensive non-element built-in circuit board.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  In the above embodiment, the opening 22a of the second substrate 22 is formed in the substantially central portion of the second substrate 22, but the present invention is not limited to this. The opening 22a may be unevenly distributed from the central portion of the second substrate 22, and, for example, as shown in FIG. 7, the opening 22a is notched inward from the side portion of the second substrate 22 (forming a recess). The opening 22a having a notch structure (recessed shape) may be used.

  Moreover, in the said embodiment, although groove part 217a, 217b was formed in the upper surface (surface by the side of a housing) of the 2nd board | substrate 22, it was set as the flexible part which is more flexible than another site | part, The structure of a flexible part is It is not limited to this. For example, only one of the groove portions 217a and 217b may be used. Further, as shown in FIG. 8, grooves 217 a and 217 b may be formed on the lower surface (surface on the housing side) of the second substrate 22 to form flexible portions. Moreover, as shown in FIG. 9, you may comprise a flexible part not by a groove part but by the through-holes 217c and 217d arranged at intervals. A combination of these may also be used. The flexible part may be provided between the fixing part 223a of the second substrate 22 and the electrical connection part 20a, but is preferably provided in an annular shape so as to surround the electrical connection part 20a.

  Moreover, in the said embodiment, although the 2nd board | substrate 22 was pressed directly in the housing direction with the packing 43 which is an elastic member arrange | positioned on the non-housing side of the 2nd board | substrate 22, it is not limited to this. . For example, as shown in FIG. 10, for example, a resin or metal plate member 44 may be interposed between the packing 43 and the second substrate 22. If the plate member 44 is provided so as to cover the entire area of the electrical connection portion 20a when viewed from the upper side in the figure, the pressing force by the packing 43 is applied evenly to the electrical connection portion 20a, and stress concentration occurs. It can be surely prevented. Further, it is more preferable that the plate member 44 is provided so as to cover the entire region where the first substrate 21 and the second substrate 22 overlap.

  Moreover, in the said embodiment, although the 2nd board | substrate 22 was fixed to the inverter cover 40 with the screw 223, and the inverter circuit 20 was positioned and fixed with respect to the housing 1 via the inverter cover 40, it is limited to this. is not. For example, for fixing the second substrate 22 to the inverter cover 40, engaging means (fixing means) other than screws may be employed. Alternatively, the second substrate 22 may be directly fixed to the housing 1 with screws or engaging means (fixing means) other than screws, and the inverter circuit 20 may be positioned and fixed with respect to the housing 1.

  For example, as shown in FIG. 11, the second substrate 22 may be fixed to the housing 1 with screws 223. In this case, the second substrate 22 may be pressed toward the housing by an elastic member disposed on the opposite side of the second substrate 22 to the housing. However, as shown in FIG. A plate member 225 made of resin or metal disposed on the opposite side of the housing may be screwed to the housing 1 to press the second substrate 22 in the direction of the housing.

  If the plate member 225 is formed in an annular shape so as to cover the entire area of the electrical connection portion 20a when viewed from the upper side in the figure, the pressing force is applied almost evenly to the electrical connection portion 20a, and stress concentration occurs. Can be reliably prevented from occurring. Further, it is more preferable that the plate member 224 is provided so as to cover the entire region where the first substrate 21 and the second substrate 22 overlap. If comprised as FIG. 11, the inverter circuit 20, the plate member 225, and the inverter cover 40 can be assembled | attached one way at a time with respect to the housing 1, and it is very preferable from a viewpoint of manufacturability.

  Also, as shown in FIG. 12, the screw 224 is disposed in the region where the first substrate 21 and the second substrate 22 overlap, and the plate member 225 disposed on the opposite side of the second substrate 22 is disposed in the housing. 1 may be screwed and pressed. According to this, it is possible to make the plate member 225 relatively small. For example, in the configuration shown in FIGS. 11 and 12, an elastic member such as a rubber gasket may be interposed between the plate member 225 and the second substrate 22.

  Moreover, in the said embodiment, although the penetration terminal 16 was electrically connected to the 1st board | substrate 21 of the inverter circuit 20, it is not limited to this, For example, as shown in FIG. It may be electrically connected to the substrate 22.

  Moreover, in the said embodiment, although the opening 22a was provided in the 2nd board | substrate 22, it is not limited to this, For example, as shown in FIG. 14, the 2nd board | substrate 22 which does not have an opening is employ | adopted. It doesn't matter.

  Moreover, in the said embodiment, while forming the flexible part which consists of groove part 217a, 217b in the 2nd board | substrate 22, the packing 43 which is an elastic member which presses the 2nd board | substrate 22 toward a housing was arrange | positioned. If the first substrate 21 can be pressed against the housing 1 without applying stress that causes a problem in the electrical connection portion 20a, either or both of the flexible portion and the elastic member can be eliminated.

  Moreover, in the said embodiment, although the penetration terminal 16 extended from the motor part 10 was arrange | positioned in the through-hole 211a of the 1st board | substrate 21, it connected to the through-hole 216a of the chip | tip 216 for thermal radiation which is an output part. However, the present invention is not limited to this. For example, an output unit that outputs supply power from the first substrate 21 to the motor unit 10 may be provided in a wiring unit such as the conductor pattern 212 instead of the heat dissipation chip 216.

  Moreover, in the said embodiment, although the chip | tip 216 for heat radiation was electrically connected with the power element 214, it is not limited to this. For example, the insulating heat radiation sheet 24 may be interposed between the conductor pattern 212 and the heat radiation chip 216.

  Moreover, in the said embodiment, although the inverter circuit 20 which is a drive circuit part was comprised with the two board | substrates of the 1st board | substrate 21 and the 2nd board | substrate 22, it is not limited to this. The inverter circuit 20 may be composed of three or more substrates including the first substrate 21 and the second substrate 22.

  In the above-described embodiment, the inverter circuit 20 that is the drive circuit unit is attached to the side surface of the housing 1 that is substantially parallel to the axial direction of the motor unit 10 (the direction in which the motor unit 10 and the compression mechanism 30 are arranged). However, it is a so-called camel-back type electric compressor, but is not limited to this, and is attached to a mounting surface formed at a portion of the outer surface of the housing 1 through which the suction refrigerant flows. If it is. For example, the motor unit 10 may be attached to the surface on the side opposite to the compression mechanism in the axial direction (the surface on the right side in FIG. 1) (a so-called inline type electric compressor may be used).

1 Housing 1c Mounting surface 10 Motor part (motor)
20 Inverter circuit (drive circuit section)
20a Electrical connection 20b Underfill (adhesive)
21 1st board | substrate 21a 1st surface 21b 2nd surface 22 2nd board | substrate 22a opening 30 compression mechanism 211 insulating base material 212a electrode 214 power element 215a circuit element 217a, 217b groove part (flexible part)
217c, 217d Through hole (flexible part)
222 Electrode 223a fixing part

Claims (5)

A compression mechanism for sucking and compressing the refrigerant;
An electric motor for driving the compression mechanism;
A drive circuit unit for driving the motor;
A housing that houses the compression mechanism and the motor, and in which a refrigerant sucked by the compression mechanism flows.
The drive circuit unit is
A first substrate having a power element built in an insulating base material for controlling power supplied to the motor, and a circuit element not mounted in the insulating base material and mounted on the surface by soldering A second substrate, wherein the first substrate and the second substrate are stacked and arranged,
The first substrate is disposed closer to the housing than the second substrate, and an electrode formed as a land is provided on a first surface which is one of both surfaces, and the electrode is the second substrate. Are electrically connected by soldering to an electrode formed as a land on the surface of the housing side of the housing to form an electrical connection portion between the first substrate and the second substrate, and a second surface which is the other surface. The surface is in contact with the mounting surface formed in the portion through which the suction refrigerant flows inside the outer surface of the housing ,
The second substrate has a fixing portion for positioning and fixing the second substrate with respect to the housing, and is more flexible than the other portion between the fixing portion and the electrical connection portion. An electric compressor characterized in that a portion is formed . The electric compressor according to claim 1 , wherein the flexible portion is formed in an annular shape surrounding the electrical connection portion. An elastic member disposed on the opposite side of the second substrate to the housing;
The electric compressor according to claim 1, wherein the elastic member presses the second substrate toward the housing. The electric compressor according to claim 3 , wherein the elastic member presses a region of the second substrate where the electrical connection portion is formed. An adhesive is interposed between the first substrate and the second substrate except for the electrical connection portion, and the first substrate and the second substrate are bonded to each other. The electric compressor according to any one of claims 1 to 4 .

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