JP2015056609A - Circuit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong a spatial distance between a conductor and a bus bar.SOLUTION: A metal substrate 41 has a metal plate 42. The metal substrate 41 has an insulating layer 43 on one surface of the metal plate 42. A conductive pattern 47, which is patterned in a desired shape, is bonded to the insulating layer 43. A bus bar 51 is bonded to the conductive pattern 47. A portion of the inner peripheral surface of an insertion hole 52 on the metal substrate 41 side is a separated portion 55. A portion different from the separated portion 55 of the inner peripheral surface of the insertion hole 52 is a contracted surface 56. The separated portion 55 inclines so as to be spaced apart from the metal plate 42 as it proceeds to the contracted surface 56 from a contact portion 54. The bus bar 51 has, on an opposite surface 53 facing the metal substrate 41, the contact portion 54 in contact with the metal substrate 41 and the separated portion 55 spaced apart from the metal substrate 41.

Description

  The present invention relates to a circuit device including a plate-like bus bar.

  As a semiconductor module having a bus bar fixed to the base, a semiconductor module described in Patent Document 1 is known. In the semiconductor module described in Patent Document 1, the bus bar is fixed to the cooler (base), and the semiconductor element is mounted on the bus bar.

JP 2012-28552 A

  By the way, in a circuit device, in addition to a bus bar through which current flows, a conductor that is not intended to flow current may be provided. In this case, it is desired to increase the spatial distance between the bus bar and the conductor so that the current flowing through the bus bar does not flow through the conductor.

  An object of the present invention is to provide a circuit device that can increase the spatial distance between a conductor and a bus bar.

  A circuit device that solves the above-described problem is a circuit device that includes a metal substrate, a metal substrate that includes a metal plate, an insulating layer provided on one surface of the metal plate, and a conductor pattern provided on the insulating layer. A plate-shaped bus bar is provided on the layer and the conductor pattern, and the bus bar has a facing surface facing the metal substrate, and a facing surface opposite to the facing surface, The opposing surface has a contact portion that contacts the metal substrate, and a separation portion that is provided on at least a part of a surface located between the contact portion and the opposite surface and is spaced apart from the metal substrate. To do.

  According to this, the spatial distance, which is the shortest distance from the metal plate to the bus bar without using the insulating layer, becomes longer than in the case where the separation portion is not provided. The metal plate is a conductor that is provided to improve heat dissipation and does not aim to flow current. Accordingly, the distance between the conductor and the bus bar can be increased. Note that the bus bar is provided on the insulating layer and the conductor pattern, not only when the bus bar is in contact with the insulating layer and the conductor pattern, but also on the insulating layer and the conductor pattern with a space therebetween. Also included are those provided on the insulating layer and the conductor pattern via a thing or inclusions.

  In the circuit device, it is preferable that the bus bar has an insertion hole through which a fixing member for fixing the bus bar to the metal substrate is inserted, and has the separation portion on an inner periphery of the insertion hole.

  According to this, the opening area of the insertion hole is smaller in the opening on the opposite surface side than the opening on the opposite surface side. For this reason, it can suppress that the pressure receiving area which receives the load of the fixing member in a bus bar decreases. When the diameter of the entire insertion hole is increased in order to increase the spatial distance from the metal plate to the insertion hole, the opening area on the opposite surface side is increased and the pressure receiving area is reduced. By suppressing that the pressure-receiving area of a bus bar becomes small, it can suppress that a load concentrates on a part of bus bar.

In the circuit device, the fixing member is preferably made of metal and inserted through the insertion hole through a resin collar.
According to this, since the opening area of the insertion hole is smaller than the opening on the opposite surface side, the contact area between the collar and the bus bar is less likely to be small. For this reason, it is suppressed that a load concentrates on a part of collar, and it is suppressed that a collar deform | transforms or breaks.

In the circuit device, the fixing member is preferably made of resin.
According to this, it is not necessary to ensure the insulation between the fixing member and the bus bar, and the collar becomes unnecessary.

  A circuit device that solves the above problems includes an insulating substrate, a bus bar that is provided on the insulating substrate and has an insertion hole, a metal fixing member that fixes the bus bar on the insulating substrate, and the fixing member. A resinous collar to be inserted, and the fixing member is inserted into the insertion hole through the collar, wherein the bus bar has an opposing surface facing the insulating substrate, and the opposing An opposing surface that is an opposite surface to the surface, and the opposing surface is at least part of a contact portion that contacts the insulating substrate and a surface located between the contact portion and the opposite surface. A gist of the present invention is that it is provided and has a separation portion that is separated from the insulating substrate, and the separation portion is provided on the inner periphery of the insertion hole.

  According to this, the spatial distance from the fixing member to the bus bar can be increased. The fixing member is a conductor that is provided to fix the bus bar to the circuit device and is not intended to flow current.

  According to the present invention, the spatial distance between the conductor and the bus bar can be increased.

The perspective view which shows the battery module in embodiment. The 2-2 sectional view taken on the line of FIG. 1 which shows the battery module in embodiment. The top view showing the circuit device in an embodiment. FIG. 4 is a sectional view taken along line 4-4 of FIG. 3 showing the circuit device according to the embodiment. Sectional drawing which shows the circuit apparatus of a comparative example. Sectional drawing which shows the modification of a circuit apparatus. Sectional drawing which shows the modification of a circuit apparatus. Sectional drawing which shows the modification of a circuit apparatus.

Hereinafter, an embodiment of a circuit device will be described.
As shown in FIGS. 1 and 2, the battery module 10 includes a plurality of battery cells 12 (for example, lithium ion secondary batteries and nickel metal hydride storage batteries) held in a battery holder 11. A heat transfer plate 13 is provided between the battery cells 12. End plates 14 are provided at both ends of the battery module 10 in the juxtaposition direction.

  The battery holder 11 holds the placement plate 15. The mounting plate 15 is disposed to face the surface of the battery cell 12 on which the terminals are provided. A metal substrate 41 is provided on the mounting plate 15. A plurality of electronic components 22 are mounted on the metal substrate 41. The electronic component 22 is a semiconductor element such as an FET (electrolytic effect transistor), for example.

  As shown in FIG. 3, the metal substrate 41 is provided with two bus bars 51 connected to the electronic component 22. One bus bar 51 has one end electrically connected to the battery cell 12 by the connecting bolt 21 and the other end connected to the electronic component 22 via the conductor pattern 47. One end of the other bus bar 51 is connected to a control device (not shown) that controls the battery module 10, and the other end is connected to the electronic component 22 via a conductor pattern 47. Each bus bar 51 is fixed to the metal substrate 41 by a bolt 23 as a fixing member. Each bus bar 51 is fixed at two locations by bolts 23. The fixing structure of the bolt 23 is the same at each location. In the present embodiment, a circuit device is configured by the metal substrate 41, the plurality of electronic components 22, and each bus bar 51. The circuit device of this embodiment is a control device that controls the battery module 10.

As shown in FIG. 4, the mounting plate 15 has a mounting plate through-hole 31 that penetrates in the thickness direction of the mounting plate 15. The mounting plate through-hole 31 has an internal thread on the inner peripheral surface.
The metal substrate 41 has an insulating layer 43 on one surface of the metal plate 42. The metal plate 42 is a member for improving the heat dissipation of the metal substrate 41, and is a conductor that is not intended to flow current. A surface 45 of the metal plate 42 opposite to the insulating surface 44 provided with the insulating layer 43 is bonded to the mounting plate 15. The metal plate 42 has a metal plate through hole 46 that penetrates in the thickness direction of the metal plate 42. The metal plate 42 is disposed such that the metal plate through hole 46 communicates with the placement plate through hole 31. On the insulating layer 43, a conductor pattern 47 patterned into a desired shape is bonded. In the present embodiment, the metal substrate 41 is configured by the metal plate 42, the insulating layer 43, and the conductor pattern 47. A flat bus bar 51 is joined on the insulating layer 43 and the conductor pattern 47. The bus bar 51 and the electronic component 22 are electrically connected by the conductor pattern 47. Note that the insulating layer 43 and the conductor pattern 47 are actually slightly thick, but are exaggerated in FIG. 4 for convenience of explanation.

  The bus bar 51 has an insertion hole 52 that penetrates in the thickness direction. The bus bar 51 is disposed so that the insertion hole 52 communicates with the metal plate through hole 46 and the placement plate through hole 31. The bus bar 51 has a contact portion 54 that contacts the metal substrate 41 and a separation portion 55 that is separated from the metal substrate 41 on the facing surface 53 that faces the metal substrate 41.

  The separation portion 55 is provided on a surface located between the contact portion 54 and an opposite surface 57 which is a surface opposite to the contact portion 54. In the present embodiment, the separation portion 55 and the opposite surface 57 are provided. A spacing portion 55 is provided on the inner peripheral surface of the insertion hole 52 located between the two.

  Specifically, the inner peripheral surface of the insertion hole 52 is inclined so that the hole diameter increases as the surface on the contact portion 54 side faces the contact portion 54. This inclined surface faces the metal substrate 41 and corresponds to the separation portion 55.

  The opening area of the insertion hole 52 is smaller in the opening on the opposite surface 57 side than in the opening on the contact portion 54 side. That is, the insertion hole 52 can also be regarded as having a reduced diameter portion that reduces the diameter of the insertion hole 52 on the opposite surface 57 side compared to the contact portion 54 side. Hereinafter, a portion of the inner peripheral surface of the insertion hole 52 that is different from the separation portion 55 is referred to as a reduced diameter surface 56. In the bus bar 51, the area of the opposite surface 57 is larger than the area of the contact portion 54.

  The bolt 23 is inserted into the insertion hole 52 through the collar 61. The collar 61 is made of an insulating resin, and includes a cylindrical insertion portion 62 that is inserted into the insertion hole 52 and a pedestal 63 that extends in a circular shape from the outer periphery of the insertion portion 62. A cylindrical upright portion 64 is erected from the periphery of the pedestal 63. The outer diameter of the insertion portion 62 is slightly smaller than the diameter of the portion where the reduced diameter surface 56 is provided in the insertion hole 52. The insertion portion 62 is inserted into the insertion hole 52 and the pedestal 63 is in contact with the opposite surface 57 of the bus bar 51.

  The bolt 23 is inserted into the insertion hole 52 through the collar 61 and is screwed into the mounting plate through hole 31 provided in the mounting plate 15. The head 24 of the bolt 23 is in contact with the pedestal 63 via the washer 25, and the load applied by the fastening force of the bolt 23 is applied to the collar 61 from the head 24 of the bolt 23 via the washer 25.

Next, the operation of the circuit device of this embodiment will be described.
When the battery cell 12 is charged and discharged, a current flows through the bus bar 51. At this time, it is necessary to secure a spatial distance (insulation distance) between the metal plate 42 and the bus bar 51 so that the current flowing through the bus bar 51 does not flow into the metal plate 42. The spatial distance is the shortest distance from the metal plate 42 to the bus bar 51 without using the insulating layer 43. In this embodiment, the spatial distance of the metal plate 42 and the inner periphery of the metal plate through-hole 46 are used. This is the shortest distance d1 from the corner portion 48 where the surface intersects to the separation portion 55 of the bus bar 51. Hereinafter, the circuit device 100 of the comparative example will be described. In the following description, only portions different from the circuit device of the embodiment will be described, and the same portions will be denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIG. 5, the circuit device 100 of the comparative example does not have the separation portion 55 on the facing surface 53 of the bus bar 51, and the entire surface of the facing surface 53 is the contact portion 54. That is, the insertion hole 104 of the bus bar 51 has the same diameter throughout.

  In the metal substrate 41, since the insulating surface 44 of the metal plate 42 is covered with the insulating layer 43, the insulating surface 44 and the corner portion 48 where the insulating surface 44 and the inner peripheral surface of the metal plate through hole 46 intersect. The shortest distance d2 from the opposite surface 53 of the bus bar 51 to the corner 102 where the inner peripheral surface of the insertion hole 104 intersects is the spatial distance. The spacing portion 55 is provided at the corner of the bus bar 51 closest to the corner 48 where the insulating surface 44 of the metal substrate 41 and the inner peripheral surface of the metal plate through hole 46 intersect.

  Further, as indicated by a broken line in FIG. 5, in order to increase the spatial distance from the metal plate 42 to the bus bar 51, the spatial distance may be increased by increasing the diameter of the insertion hole 52 provided in the bus bar 51. Conceivable. However, in this case, the contact area between the collar 61 and the opposite surface 57 of the bus bar 51 (the pressure receiving area of the bus bar 51) is reduced by the amount that the diameter of the insertion hole 52 is increased. When the contact area is small, the load from the bolt 23 is concentrated on a part of the collar 61, and the collar 61 may be deformed or damaged.

In the present embodiment, the spatial distance between the bus bar 51 and the metal plate 42 is increased without reducing the contact area between the bus bar 51 and the collar 61.
By the way, when forming the insertion hole 52 with a drill etc., in order to make the periphery of the insertion hole 52 smooth, the periphery of the insertion hole 52 may be chamfered. In this case, an inclined surface is provided on the periphery of the insertion hole 52 of the bus bar 51. In the present embodiment, the bus bar 51 is disposed so that the inclined surface faces the metal substrate 41 so that the inclined surface functions as a separation portion. Further, when both the contact portion 54 side and the opposite surface 57 side of the insertion hole 52 are chamfered and inclined surfaces are formed on both the contact portion 54 side and the opposite surface 57 side, the contact portion 54 side The inclination of the inclined surface is made gentler than the inclination on the opposite surface 57 side.

Therefore, according to the above embodiment, the following effects can be obtained.
(1) The bus bar 51 is provided with a separation portion 55 that is separated from the metal substrate 41. For this reason, the spatial distance between the bus bar 51 and the metal plate 42 can be increased.

  (2) A part of the inner peripheral surface of the insertion hole 52 of the bus bar 51 is a separating portion 55. When the diameter of the insertion hole 52 is increased in order to increase the spatial distance, the contact area between the collar 61 and the bus bar 51 is reduced, and the load from the bolt 23 is concentrated on a part of the bus bar 51. When the load is concentrated on a part of the bus bar 51, the bus bar 51 is deformed. In the present embodiment, by increasing the diameter only on the contact portion 54 side of the insertion hole 52, it is possible to suppress the load from being concentrated on a part of the bus bar 51 and to prevent the bus bar 51 from being deformed.

  (3) By increasing the diameter only on the contact portion 54 side of the insertion hole 52, it is possible to increase the spatial distance while suppressing the load from being concentrated on a part of the collar 61. For this reason, deformation and breakage of the collar 61 can be suppressed.

  (4) If an insulating substrate is used instead of the metal substrate 41 provided with the insulating layer 43 on the metal plate 42, it is not necessary to secure a spatial distance between the metal plate 42 and the bus bar 51. High heat dissipation compared to For this reason, by using the metal substrate 41, the heat generated by the electronic component 22 can be efficiently radiated.

In addition, you may change embodiment as follows.
As shown in FIG. 6, instead of the metal substrate 41, an insulating substrate 71 made of an insulating material may be used. The facing surface 72 of the bus bar 51 faces the insulating substrate 71. The facing surface 72 has a contact portion 73 that contacts the insulating substrate 71 and a separation portion 74 that is separated from the insulating substrate 71. In this case, since the metal plate 42 is not provided, it is not necessary to increase the spatial distance between the metal plate 42 and the bus bar 51. On the other hand, since the metal bolt 23 is a conductor that is not intended to pass current, it is necessary to increase the spatial distance from the metal bolt 23 to the bus bar 51 without passing through the insulator (collar 61). . Even in this case, as in the embodiment, when the separation portion 74 is provided, the shortest distance d3 from the bolt 23 to the bus bar 51 without the collar 61 is longer than that in the case where the separation portion 74 is not provided. .

  As shown in FIG. 7, the separation portion 55 may be provided on the side surface 59 of the bus bar 51. The side surface 59 is a surface located between the facing surface 53 and the opposite surface 57. In this case, the bus bar 51 may be bonded to the metal substrate 41 with a conductive bonding material such as solder or silver paste. In this case, the side surface 59 is a surface connecting the contact portion 54 and the opposite surface 57.

  ○ As shown in FIG. 8, the separation portion 55 may not be inclined. The insertion hole 52 is configured by connecting a first insertion hole 81 and a second insertion hole 82 having a diameter larger than that of the first insertion hole 81. The first insertion hole 81 is provided on the opposite surface 57 side, and the second insertion hole 82 is provided on the facing surface 53 side. A separating portion 55 that connects the inner peripheral surface of the first insertion hole 81 and the inner peripheral surface of the second insertion hole 82 is provided on a surface between the opposing surface 53 and the opposite surface 57, and faces the metal substrate 41. doing. In this case, the shortest distance d4 from the corner portion 48 to the inner peripheral surface of the second insertion hole 82 is the spatial distance.

  ○ The bolt 23 may be made of resin. When the bolt 23 is made of resin, no current flows through the bolt 23, so that the bolt 23 can be directly inserted into the insertion hole 52 of the bus bar 51 without providing the collar 61. Therefore, the fastening force of the bolt 23 is directly applied to the bus bar 51 from the head 24 of the bolt 23.

In place of the bolt 23, the bus bar 51 may be fixed to the metal substrate 41 by a caulking member that is caulked to an edge such as the mounting plate through hole 31 as a fixing member.
The circuit device is not limited to a control device that controls the battery module 10. For example, a circuit device constituting a DCDC converter may be used.

The reduced diameter surface 56 that does not face the metal substrate 41 may not be provided. That is, the entire inner peripheral surface of the insertion hole 52 may be the separation portion 55.
The metal substrate 41 may not have the conductor pattern 47, and the bus bar 51 and the electronic component 22 may be connected to each other by the bus bar 51 or a conductive wire.

  A female screw may be provided on the inner periphery of the metal plate through hole 46 so that the bolt 23 is screwed into the metal plate through hole 46. Further, a nut to which the bolt 23 inserted through the metal plate through hole 46 is screwed may be provided, and the bolt 23 may be fastened by screwing the bolt 23 to the nut.

The contact portion 54 may not be in direct contact with the metal substrate 41, and a conductive inclusion may be provided between the contact portion 54 and the metal substrate 41.
The bus bar 51 may be provided on the insulating layer 43 and the conductor pattern 47 with a space between them, or may be provided on the insulating layer 43 and the conductor pattern 47 through inclusions. That is, the bus bar 51 being provided on the insulating layer 43 and the conductor pattern 47 is not limited to the case where the bus bar 51 is in contact with the insulating layer 43 and the conductor pattern 47.

  The circuit device may be composed of a metal substrate 41 and a bus bar 51. That is, the electronic component 22 may not be mounted.

  DESCRIPTION OF SYMBOLS 23 ... Bolt, 41 ... Metal substrate, 42 ... Metal plate, 43 ... Insulating layer, 44 ... Insulating surface, 51 ... Bus bar, 52 ... Insertion hole, 53 ... Opposing surface, 54 ... Contact part, 55 ... Separation part, 57 ... Opposite side, 61 ... color.

Claims (5)

A metal plate,
An insulating layer provided on one surface of the metal plate;
A circuit device comprising a metal substrate having a conductor pattern provided on the insulating layer,
A plate-like bus bar is provided on the insulating layer and the conductor pattern,
The bus bar has a facing surface facing the metal substrate, and a facing surface that is a surface opposite to the facing surface,
The facing surface includes a contact portion that contacts the metal substrate, and a separation portion that is provided on at least a part of a surface located between the contact portion and the opposite surface and spaced from the metal substrate. A circuit device. The bus bar has an insertion hole through which a fixing member for fixing the bus bar to the metal substrate is inserted,
The circuit device according to claim 1, wherein the separation portion is provided on an inner periphery of the insertion hole.   The circuit device according to claim 2, wherein the fixing member is made of metal and is inserted into the insertion hole via a resin collar.   The circuit device according to claim 2, wherein the fixing member is made of resin. An insulating substrate;
A bus bar provided on the insulating substrate and having an insertion hole;
A metal fixing member for fixing the bus bar on the insulating substrate;
A resinous collar into which the fixing member is inserted, and a circuit device in which the fixing member is inserted into the insertion hole through the collar,
The bus bar has a facing surface facing the insulating substrate, and a facing surface that is a surface opposite to the facing surface,
The opposing surface has a contact portion that contacts the insulating substrate, and a separation portion that is provided on at least a part of a surface located between the contact portion and the opposite surface and is spaced from the insulating substrate,
The circuit device according to claim 1, wherein the separation portion is provided on an inner periphery of the insertion hole.