WO2018203496A1

WO2018203496A1 - Connection structure for conductive member and electric compressor equipped with same

Info

Publication number: WO2018203496A1
Application number: PCT/JP2018/016660
Authority: WO
Inventors: 裕司佐々木; 優石川; 良宣松沢; 雅明宍戸
Original assignee: 株式会社Ihi
Priority date: 2017-05-01
Filing date: 2018-04-24
Publication date: 2018-11-08
Also published as: JP2018190579A

Abstract

In the connection structure according to the present invention, a substrate has a through-hole formed therein that penetrates a conductor plate, an insulation layer, and a base substrate in the respective thickness directions thereof. The connection structure is provided with a fastening member which comprises: a shaft part inserted into a hole part and into the through-hole; a head part which is provided to a first end of the shaft part and which is locked on a connection part; and a nut which is provided to a second end of the shaft part and which is locked on the base substrate. The base substrate comprises: an isolation part surrounding the through-hole; and a peripheral part surrounding the isolation part. Provided between the isolation part and the peripheral part is a resin part that surrounds the isolation part and extends to reach the insulation layer in the thickness direction. The nut of the fastening member is configured to be within the ranges of the resin part and the isolation part.

Description

Connection structure of conductive members and electric compressor including the same

The present disclosure relates to a connection structure of conductive members and an electric compressor including the same.

As described in Patent Document 1, there is known a connection structure in which a terminal is connected to a copper pattern on an aluminum substrate. In this connection structure, the terminals are fixed to the copper pattern by soldering. An H-shaped electrode pattern is formed on the copper pattern. A terminal is soldered to this electrode pattern.

Japanese Utility Model Application Publication No. 5-79974

Since a metal substrate such as aluminum is excellent in heat dissipation, it can be adopted as an inverter or converter for large current. For example, a circuit made of copper foil or the like is formed on the front surface side of the substrate, and a base substrate is provided on the back surface side of the substrate. When an external circuit is electrically connected to the circuit, a conductive member (for example, a terminal) is used. The conductive member is soldered to the surface of the substrate as described in Patent Document 1 above.

Generally, the size of the conductive member through which a large current flows is large. In addition, a large amount of heat is required for soldering to a base substrate with good heat dissipation. Further, for example, when a semiconductor element such as a MOSFET (Metal-Oxide-semiconductor field-effect transistor) is mounted near a conductive member, the semiconductor element may be damaged by heat for soldering. Thus, soldering is a connection method with some limitations.

The present disclosure describes a connection structure of a conductive member in which the degree of freedom of connection of a conductive member to a metal substrate is increased, and an electric compressor including the same.

One aspect of the present disclosure is a connection structure of a conductive member in which a conductive member is electrically connected to a circuit provided on a first surface of a substrate, and the substrate is disposed on the first surface side to form a circuit. A conductive base plate made of metal, a base substrate made of metal disposed on the second side opposite to the first side, and an insulating layer disposed between the conductive plate and the base base plate; A conductive plate, an insulating layer, and a through hole penetrating the base substrate in the thickness direction are formed, and a hole communicating with the through hole is formed in the conductive member, and the conductive member is fixed to the substrate A fixing member, which is inserted into the through hole and the hole, and is provided at the shaft end including the first end on the first surface side and the second end on the second surface side, and at the first end of the shaft portion The first end, which is larger than the hole, is engaged with the conductive member, and is provided at the second end of the shaft, is larger than the through hole, and is formed on the base substrate. And a base member including an isolation portion surrounding the through hole and a peripheral portion surrounding the isolation portion, the base substrate comprising: A resin portion surrounding the isolation portion and reaching the insulating layer in the thickness direction is provided, and the second end portion of the fixing member is within the range of the resin portion and the isolation portion.

According to one aspect of the present disclosure, the degree of freedom in connection of the conductive member to the metal substrate is enhanced.

FIG. 1 is a cross-sectional view showing a connection structure according to an embodiment of the present disclosure. FIG. 2 is a bottom view showing the connection structure of FIG. FIG. 3 is a schematic view showing an example in which the connection structure of FIG. 1 is applied to an electric compressor. FIG. 4 is a cross-sectional view showing a connection structure according to a comparative example.

According to the connection structure of the conductive members, the substrate is formed with the conductive plate, the insulating layer, and the through hole penetrating the base substrate in the thickness direction. The shaft portion of the fixing member is inserted into the through hole and the hole portion of the conductive member. The first end and the second end provided at both ends of the shaft are locked on the conductive member and on the base substrate (more specifically, on the separation portion), whereby the conductive member is fixed to the substrate It is fixed. The second end of the fixing member is in contact with the isolation portion of the base substrate, but the isolation portion is insulated with respect to the peripheral portion by the resin portion reaching the insulating layer. The second end of the fixing member is in the range of the resin portion and the separating portion, and does not contact the peripheral portion. Therefore, the peripheral portion is insulated from the conductive member, the conductive plate, the fixing member and the isolation portion, and a short circuit between the circuit of the conductive plate and the peripheral portion of the base substrate does not occur. As described above, since the conductive member is connected using the through hole and the fixing member including the shaft portion, the limitation associated with the above-described conventional technology (for example, the solder connection structure) is alleviated. Thus, the degree of freedom in connection of the conductive member to the metal substrate is enhanced.

In some embodiments, the fixing member comprises a bolt including the shank and one of the first end and the second end, and a nut that is the other of the first end and the second end. The conductive member is fixed to the substrate by screwing the shaft of the bolt with respect to the nut. In this case, the conductive member can be easily fastened and fixed to the substrate by the bolt and the nut.

In some embodiments, the isolation portion is provided on the edge of the substrate in the direction orthogonal to the thickness direction, and the resin portion reaches the edge of the substrate. The edge of the substrate is, for example, a side or a corner of the substrate. Since the resin portion is provided to reach the edge of the substrate, the resin portion and the isolation portion surrounded by the resin portion can be easily formed.

In some embodiments, the standoffs are rectangular in shape. The rectangular shaped separator has a larger area than when the separator is circular. Thus, it is suitable for the seat surface of the second end. Since the resin portion also has a rectangular shape, it is easy to form the resin portion. If the second end is rectangular in shape, the standoff may conform to the shape of the second end, thus minimizing its area. As a result, for example, the cooling performance by the peripheral portion can be sufficiently secured.

An electric compressor according to another aspect of the present disclosure has a substrate, and a motor in which the conductive member is electrically connected to the substrate by the connection structure of any of the conductive members described above; Equipped with In this case, the degree of freedom of connection of the conductive members can be enhanced even for the electric compressor that can flow a large current.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols and redundant description will be omitted.

The connection structure 100 of the present embodiment will be described with reference to FIGS. 1 and 2. The connection structure 100 is a structure for electrically connecting a terminal (conductive member) 40 to the substrate 1 which is a metal substrate. The substrate 1 is, for example, a power substrate through which a large current flows. The terminal 40 connected to the substrate 1 is a terminal for flowing a large current. Terminal 40 may be, for example, a bus bar or the like.

The terminal 40 includes a flat connection portion 41 connected to the substrate 1 and a lead-out portion 42 provided continuously to the connection portion 41. The terminal 40 is, for example, an L-shaped component, but the shape of the terminal 40 is not limited to the L-shape. The lead portion 42 of the terminal 40 is connected to, for example, a power supply.

A plurality of terminals 40 may be connected to the substrate 1. One or more connection structures 100 are provided on the side 1 c (see FIG. 2) of the substrate 1. The connection structure 100 may be provided at the corner of the substrate 1. The substrate 1 having a rectangular shape as a whole has edge portions such as the side portions 1c and corner portions. The connection structure 100 is provided at these end edges. The edge means an edge in a direction orthogonal to the thickness direction of the substrate 1. The connection structure 100 may be provided in a portion other than the edge portion of the substrate 1, for example, in the central portion.

The substrate 1 includes a first surface 1a, which is a surface to which the terminal 40 is connected, and a second surface 1b opposite to the first surface 1a. The substrate 1 has a metal base substrate 3 on the second surface 1 b side. Thus, the heat dissipation of the substrate 1 is enhanced. The second surface 1 b of the substrate 1 may be connected to a cooling unit (not shown) in a region excluding the separation unit 21 described later.

The substrate 1 includes a conductive plate 2 disposed on the first surface 1 a side, a metal base substrate 3 disposed on the second surface 1 b side, and an insulation disposed between the conductive plate 2 and the base substrate 3. And a layer 4. The base substrate 3, the insulating layer 4 and the conductive plate 2 are stacked in this order and bonded to each other. Conductive plate 2 includes a front surface 2 a corresponding to first surface 1 a and a back surface 2 b opposite to conductive plate 2. Base substrate 3 includes a back surface 3 b corresponding to second surface 1 b and a front surface 3 a opposite to back surface 3 b. Insulating layer 4 includes a front surface 4 a facing back surface 2 b of conductive plate 2 and a back surface 4 b opposite to front surface 3 a of base substrate 3 opposite to front surface 4 a. The back surface 2 b of the conductive plate 2 and the surface 4 a of the insulating layer 4 are in contact with each other in a planar manner. The front surface 3a of the base substrate 3 and the back surface 4b of the insulating layer 4 are in flat contact with each other.

Conductive plate 2 is, for example, a metal foil. Conductive plate 2 may be, for example, a copper foil or the like. The conductive plate 2 is formed with a circuit to which the terminal 40 is electrically connected.

Base substrate 3 is a substrate made of, for example, aluminum. The base substrate 3 is attached to, for example, an apparatus to which the connection structure 100 is applied. The base substrate 3 is a cooling unit that dissipates heat generated by an inverter, a converter, or the like. The base substrate 3 may be connected to cooling means (not shown). The base substrate 3 may be made of iron or copper.

Insulating layer 4 is made of, for example, a thermosetting resin. Insulating layer 4 may be made of, for example, an epoxy resin. The insulating layer 4 insulates the base substrate 3 from the conductive plate 2. As a material which constitutes insulating layer 4, other publicly known insulating materials may be used.

The connection structure 100 includes a fastening member (fixing member) 10 for fixing the terminal 40 to the substrate 1. In the present embodiment, the bolt 13 and the nut (second end) 14 are used as the fastening member 10. Hereinafter, the fixing structure using the fastening member 10 will be described in detail.

As shown in FIG. 1, in the substrate 1, a through hole 5 penetrating in the thickness direction is formed. The through holes 5 are through holes penetrating the conductive plate 2, the insulating layer 4, and the base substrate 3 in the thickness direction. More specifically, in the conductive plate 2, for example, a cylindrical hole 2c is formed. In the insulating layer 4, for example, a cylindrical hole 4 c is formed. For example, a cylindrical hole 3 c is formed in the base substrate 3. The holes 2c, the holes 4c, and the holes 3c communicate with each other. The through hole 5 of the substrate 1 is formed by combining the hole 2c, the hole 4c, and the hole 3c.

The axes of the hole 2c, the hole 4c, and the hole 3c may coincide with each other. That is, the hole 2c, the hole 4c, and the hole 3c may be formed concentrically with respect to one axis. The diameters of the hole 2c, the hole 4c, and the hole 3c may be equal.

On the other hand, in the connection portion 41 of the terminal 40, for example, a cylindrical hole portion 41c is formed. The connection portion 41 is superimposed on the surface 2 a of the conductive plate 2 and is in contact with the circuit described above. The hole 41 c is in communication with the through hole 5.

The shaft 12 of the bolt 13 of the fastening member 10 is inserted through the hole 41 c of the terminal 40 and the through hole 5 of the substrate 1. The shaft portion 12 includes a first end disposed in the hole 41 c and a second end projecting from the second surface 1 b side of the through hole 5. The bolt 13 includes a head (first end) 11 provided at a first end of the shaft 12. The diameter of the head 11 (the width in the direction perpendicular to the axis of the shaft 12) is larger than the diameter of the hole 41c, for example, larger than the diameter of the through hole 5. The head 11 is locked on the connection portion 41. The head 11 may have a hexagonal shape that allows the rotary tool to be fitted. It is sufficient if a predetermined rotary tool can be fitted to the head 11. The shape of the head 11 is not limited. For example, the shape of the head 11 may be dish-like.

The nut 14 is provided at the second end of the shaft 12. The diameter of the nut 14 (the width in the direction perpendicular to the axis of the shaft 12) is larger than the diameter of the through hole 5, for example, larger than the diameter of the hole 41c. The nut 14 is locked on the back surface 3 b of the base substrate 3.

In the connection structure 100, the connection portion 41 of the terminal 40 is fixed to the substrate 1 by screwing the bolt 13 into the nut 14. The nut 14 disposed on the second surface 1 b side of the substrate 1 may be fixed to, for example, the back surface 3 b of the base substrate 3. The nut 14 may be accommodated in a recess of a member separate from the substrate 1. In this case, the nut 14 may be a floating nut. The nut 14 is not limited to a hexagonal shape, and may be a square. By adopting a configuration in which the nut 14 does not need to be gripped by a tool or the like, for example, even when the space on the second surface 1 b side of the substrate 1 is limited, the workability of tightening can be ensured.

The head 11 of the bolt 13 is crimped (contacted) to the connecting portion 41 by the fastening force of the fastening member 10, and the nut 14 is crimped (contacted) to the base substrate 3. The substrate 1 and the connection portion 41 are sandwiched and fixed by the head 11 and the nut 14.

Here, as shown in FIG. 1 and FIG. 2, the base substrate 3 includes an isolation portion 21 surrounding the through hole 5 and a peripheral portion 22 further enclosing the isolation portion 21. The isolation portion 21 and the peripheral portion 22 are made of, for example, the same material and have the same thickness. The isolation part 21 has, for example, a rectangular shape (see FIG. 2). The peripheral portion 22 may be connected to cooling means (not shown).

A resin portion 30 is provided between the isolation portion 21 and the peripheral portion 22. Resin portion 30 is made of, for example, a thermosetting resin. Resin portion 30 may be filled, for example, without a gap between isolation portion 21 and peripheral portion 22. Resin portion 30 may be made of, for example, an epoxy resin. In addition, the material which comprises the resin part 30 is not restricted to an epoxy resin. The resin portion 30 may be made of another thermosetting resin.

As shown in FIG. 2, the resin portion 30 surrounds the isolation portion 21. In the connection structure 100 provided on the side portion 1c of the substrate 1, the two end faces 30c and 30c of the U-shaped (or C-shaped) resin portion 30 reach the side portion 1c. Further, as shown in FIG. 1, the resin portion 30 reaches the insulating layer 4 in the thickness direction. That is, the resin portion 30 is in contact with the back surface 4 b of the insulating layer 4 over the entire length. The resin portion 30 electrically insulates the isolation portion 21 from the peripheral portion 22.

The nut 14 of the fastening member 10 is within the range of the separating portion 21. The nut 14 may be within the range of the resin portion 30 and the separating portion 21. That is, the size of the nut 14 and the sizes of the separating part 21 and the resin part 30 are set so that the nut 14 does not contact the peripheral part 22. In other words, the circumscribed circle (the circle passing through each vertex) of the nut 14 may be within the range of the resin portion 30 and the separating portion 21. It is preferable that the circumscribed circle of the nut 14 does not extend beyond the resin portion 30. The circumscribed circle of the nut 14 may be located inside the inner edge 30 b of the resin portion 30 or may intersect the inner edge 30 b but does not intersect the outer edge 30 a of the resin portion 30.

Subsequently, a method of manufacturing the connection structure 100 will be described. First, a U-shaped (or C-shaped) hole (sag) is formed in the base substrate 3 (slit processing). Thereby, the area | region corresponded to the resin part 30 is formed. The base substrate 3 is cut so as to cut both ends of the hole. Thus, a portion corresponding to the end face 30c is formed. Insulating layer 4 is formed on surface 3 a of base substrate 3. Subsequently, the resin portion 30 is formed in the hole. At this time, the resin portion 30 is formed to reach the insulating layer 4. Furthermore, a circuit is formed on the insulating layer 4. Then, in the central region surrounded by the resin portion 30, the through hole 5 penetrating in the thickness direction is formed. The terminal 40 is placed on the substrate 1 by placing the connection portion 41 of the terminal 40 on the first surface 1 a of the substrate 1 and screwing the bolt 13 through the hole 41 c and the through hole 5 to the nut 14 disposed on the second surface 1 b side. It is fixed to 1.

The connection structure 100 can be used for any electrical device. For example, as shown in FIG. 3, the connection structure 100 may be applied to an electric compressor 50 in which a large current flows. The electric compressor 50 compresses air and supplies the compressed air to an engine or the like. The electric compressor 50 includes an inverter 54, a motor 52, and a compressor 51 connected to the motor 52 via a rotating shaft 53. The inverter 54 converts direct current power supplied from the power supply 70 into alternating current power, and supplies the alternating current power to the motor 52. The motor 52 is driven by being supplied with AC power from the inverter 54. The compressor 51 attached to the rotating shaft 53 of the motor 52 is rotated by driving the motor 52. The rotation of the compressor 51 compresses the air. Connection structure 100 is provided, for example, in inverter 54. The connection structure 100 may be provided between the power supply 70 and the inverter 54 and may be a structure for electrically connecting them (see virtual lines in FIG. 3).

According to the connection structure 100 of the terminal 40, the substrate 1 is formed with the through holes 5 penetrating the conductive plate 2, the insulating layer 4, and the base substrate 3 in the thickness direction. The shaft 12 of the fastening member 10 is inserted into the through hole 5 and the hole 41 c of the terminal 40. The head 40 and the nut 14 provided at both ends of the shaft portion 12 are locked on the terminal 40 and the base substrate 3 (more specifically, on the separation portion 21), so that the terminal 40 is mounted on the substrate 1 It is fixed. The nut 14 of the fastening member 10 is in contact with the isolation portion 21 of the base substrate 3, but the isolation portion 21 is insulated from the peripheral portion 22 by the resin portion 30 reaching the insulating layer 4. The nut 14 of the fastening member 10 is within the range of the resin portion 30 and the separating portion 21 and does not contact the peripheral portion 22. Therefore, the peripheral portion 22 is insulated from the terminal 40, the conductive plate 2, the fastening member 10, and the separation portion 21, and a short circuit between the circuit of the conductive plate 2 and the peripheral portion 22 of the base substrate 3 does not occur. As described above, since the terminal 40 is connected using the through hole 5 and the fastening member 10 including the shaft portion 12, the limitation associated with the above-described prior art (for example, the soldering connection structure) is alleviated. Thus, the degree of freedom in connection of the terminal 40 to the metal substrate is enhanced.

For example, since the space of the fastening member 10 only needs to be secured, space saving is realized as compared with the case where the solder portion 210 is provided. In addition, even when a semiconductor element such as a MOSFET is mounted near the conductive member, the situation that the semiconductor element is damaged or destroyed by the heat for soldering is avoided. Further, as in the connection structure 200 shown in FIG. 4, the second connection member 202 which is a terminal of the external circuit is separately fastened by the fastening member 203 to the first connection member 201 soldered in the solder portion 210 It takes time and effort to weld. In the above embodiment, the terminals 40 can be connected with a simple configuration. There is no need to solder the terminals 40, and an excessive amount of heat is not required in the mounting process of the substrate 1, and the thermal stress on other mounted components is reduced. The connection of the terminal 40 such as a bus bar to the substrate 1 is facilitated, and the freedom in shape design of the substrate 1 and the terminal 40 is expanded. Furthermore, the peripheral portion 22 enhances the heat dissipation of the substrate 1. The heat dissipation of the substrate 1 is further enhanced by the peripheral portion 22 being connected to the external cooling means and being cooled.

The terminal 40 can be easily fastened and fixed to the substrate 1 by the bolt 13 and the nut 14 of the fastening member 10. The terminal 40 can be directly fastened to the substrate 1 by the bolt 13 and the nut 14.

Since the resin portion 30 is provided to reach the side portion 1 c of the substrate 1, the resin portion 30 and the isolation portion 21 surrounded by the resin portion 30 can be easily formed.

The rectangular separating portion 21 has a large area as compared with the case where the separating portion 21 is circular. Thus, it is suitable for the bearing surface of the nut 14. Since the resin portion 30 also has a rectangular shape, the resin portion 30 can be easily formed. If the nut 14 is rectangular in shape, the standoff 21 conforms to the shape of the nut 14 so that its area can be minimized. As a result, for example, the cooling performance by the peripheral portion 22 can be sufficiently secured.

When the connection structure 100 is applied to the motor-driven compressor 50, the degree of freedom in connection of the terminal 40 is enhanced even for the motor-driven compressor 50 in which a large current can flow. For example, the terminal 40 can be easily connected to a power substrate (metal substrate) that can be employed for the inverter 54 of the electric compressor 50. The peripheral portion 22 enhances the heat dissipation of the substrate 1. The heat dissipation of the substrate 1 is further enhanced by the peripheral portion 22 being connected to the external cooling means and being cooled.

Although the embodiment of the present disclosure has been described, the present disclosure is not limited to the above embodiment. For example, the shape of the isolation may be any other shape. The separator may not be provided at the end of the substrate 1.

The configuration of the fixing member may be changed as appropriate. For example, the shaft portion and the second end may be integrated, a bolt may be inserted from the second surface 1 b side of the substrate 1, and a nut may be provided on the connection portion 41 side of the terminal 40. A nut corresponding to the first end and a nut corresponding to the second end may be screwed into the stud bolt. Other than the fastening member may be adopted. For example, a rivet structure or a socket structure may be employed. A caulking structure may be employed.

The connection structure 100 may be applied to a noncontact power feeding system or the like.

According to some aspects of the present disclosure, the freedom of connection of the conductive member to the metal substrate is enhanced.

1 substrate 1a first surface 1b second surface 1c side portion (edge portion)
2 conductive plate 3 base substrate 4 insulating layer 5 through hole 10 fastening member (fixing member)
11 head (first end)
12 shaft portion 13 bolt 14 nut (second end)
21 separation portion 22 peripheral portion 30 resin portion 40 terminal (conductive member)
41c hole 50 electric compressor 51 compressor 52 motor 100 connection structure

Claims

A connection structure of a conductive member in which the conductive member is electrically connected to a circuit provided on the first surface of the substrate,
The substrate is
A conductive plate disposed on the first surface side and having the circuit formed thereon;
A metal base substrate disposed on a second surface opposite to the first surface;
An insulating layer disposed between the conductive plate and the base substrate;
In the substrate, a through hole penetrating the conductive plate, the insulating layer, and the base substrate in a thickness direction is formed, and in the conductive member, a hole communicating with the through hole is formed.
A fixing member for fixing the conductive member to the substrate, which is inserted into the through hole and the hole and includes a first end on the first surface side and a second end on the second surface side. A shaft portion, the first end portion of the shaft portion provided at the first end, the first end portion being larger than the hole and engaged on the conductive member, and provided at the second end of the shaft portion; And a second end portion larger than the through hole and locked on the base substrate.
The base substrate includes an isolation portion surrounding the through hole and a peripheral portion surrounding the isolation portion.
Between the isolation portion and the peripheral portion, a resin portion which surrounds the isolation portion and reaches the insulating layer in the thickness direction is provided.
The connection structure of a conductive member, wherein the second end of the fixing member is within the range of the resin portion and the separating portion.
The fixing member is
A bolt including the shaft and any one of the first end and the second end;
And a nut that is the other of the first end and the second end,
The connection structure of a conductive member according to claim 1, wherein the conductive member is fixed to the substrate by screwing the shaft portion of the bolt with respect to the nut.
The connection structure for a conductive member according to claim 1 or 2, wherein the isolation portion is provided at an edge of the substrate in a direction orthogonal to the thickness direction, and the resin portion reaches the edge of the substrate. .
The connection structure of a conductive member according to any one of claims 1 to 3, wherein the separation part has a rectangular shape.
A motor comprising the substrate and the conductive member electrically connected to the substrate by the conductive member connection structure according to any one of claims 1 to 4.
And a compressor coupled to the motor.