JP4396628B2 - Busbar connection type electronic circuit device and assembly method thereof - Google Patents

Description

  The present invention relates to a power electronic circuit device formed by fastening a plurality of power electronic components, more preferably a large number of power electronic components, to a bus bar and a heat dissipating member which are parallel to each other, and to an improvement of the assembly method.

  Conventionally, in power electronic circuit devices that use multiple power electronic components that consume a large amount of power, such as motor control devices for electric vehicles and DC-DC converters for vehicles, a bus bar is connected to the terminal provided on the upper surface of these power electronic components. In addition, it is common to attempt to radiate heat by fixing the bottom surface of each power electronic component to a metal heat sink or a bottom plate portion of a metal case.

  Therefore, in this type of power electronic circuit device (power electronic circuit device), at least the terminal connection portion of the bus bar is disposed in parallel to the upper surface of a heat radiating member such as a metal heat radiating plate or a metal case. Of course, a step may be provided in a portion of the bus bar between the power electronic components according to the height of each power electronic component, or a step may be provided on the upper surface of the heat dissipation member. Note that the upper and lower directions in this specification are directions for convenience, and do not prevent the entire apparatus from being assembled in a state where it is spatially rotated by a predetermined angle.

  A typical assembly process of this type of power electronic circuit device will be described with reference to FIGS.

First, for example, the power electronic components 2 to 4 are fixed to the bottom surface of the metal case 1 by fastening or the like (FIG. 10), and then the female screw holes of the power electronic components 2 to 4 are aligned with the through holes of the bus bar 5 (FIG. 10). 11) Next, bolts or male screws are screwed into these holes to complete the fixing of the bus bar 5 and the electrical connection between the bus bar 5 and the power electronic components 2 to 4 (FIG. 12). An example of this type of power electronic circuit device is described in the following Patent Document 1 filed by the present applicant.
JP 2002-83915 A

  However, it has been found that the above-described conventional bus bar connection type electronic circuit device may cause the following problems. That is, due to variations in the height of each power electronic component, each power electronic component is fastened to, for example, the top surface of the metal heat sink or the bottom surface of the metal case, and the bus bar is fastened to the terminal portion of each electronic component. A phenomenon has occurred in which the thermal conductivity between the power electronic component and, for example, the bottom surface of the metal case varies.

  More specifically, although the power electronic component having a relatively large height is strongly pressed against the bottom surface of the metal case by the elastic deformation of the bus bar and can secure good heat conduction, the power electronic component having a relatively small height is used. On the other hand, the force acting away from the bottom surface of the metal case acts on the component, and the thermal conductivity between the bottom surface of the power electronic component and the bottom surface of the metal case decreases, and as a result, the temperature of the electronic component having a relatively small height. As a result, there was a possibility that the life would deteriorate.

  The above-described problem of increasing the thermal resistance between the bottom surface of the electronic component having a relatively small height and the bottom surface of the metal case is particularly the two of the two power electronic components arranged in the longitudinal direction of the bus bar. This becomes conspicuous when the height of the power electronic component is substantially smaller than the height of the power electronic component on the center side. That is, in this case, since the power electronic component on the center side is pulled upward from the power electronic components on both sides through the bus bars, the force to move away from the bottom surface of the metal case is doubled.

  In addition, the conventional assembly method for the power electronic component in which the metal heat sink or the metal case and the bus bar are assembled is as follows. First, each power electronic component is fastened to the upper surface of the metal heat sink or the bottom surface of the metal case, and then the metal heat dissipation. The bus bar was fastened to the terminal portion of each power electronic component fastened to the board.

  In this assembling method, it is necessary to fasten each power electronic component to a predetermined position on the bottom surface of the metal case one by one, which makes the alignment work complicated, and in addition, the power electronic component and the bottom surface of the metal case. Since the variation in the assembly position increases the positional variation of the terminal portion of each power electronic component, there is also a problem that the fastening of the terminal portion and the bus bar becomes troublesome.

  The present invention has been made in view of the above problems, and provides a bus bar connection type electronic circuit device that is excellent in workability and can suppress an increase in thermal resistance between a power electronic component and a heat radiating member, and an assembling method thereof. Its purpose is to do.

  A bus bar connection type electronic circuit device according to a first aspect of the present invention that solves the above problems includes a plurality of power electronic components, a metal heat dissipating member with the power electronic components fastened to the upper surface, and the upper surfaces of the power electronic components. A bus bar which is fastened to the terminal portion of the power bar and electrically connects each power electronic component, and the fastening portion of the bus bar to at least the power electronic component is at least the bottom surface of the power electronic component among the top surfaces of the heat dissipation member In the power electronic circuit device disposed substantially parallel to the portion in contact with the two, the two power electrons on both ends of the three or more power electronic components arranged in the longitudinal direction of the common bus bar When a component is attached to the heat dissipating member and the bus bar, a space generated between the heat dissipating member and the bus bar at the installation position of the power electronic component on the center side. That the height of the component installation space is characterized in that it is set lower than the height of the power electronic components of the central side provided in the component installation space.

  That is, according to the present invention, for example, the bus bar and the heat radiating member at the position of the central power electronic component in a state where the power electronic components on both ends of the three power electronic components arranged in a row are fastened to the bus bar and the heat radiating member. The manufacturing tolerance of the height of each power electronic component is set so that the component installation space defined as a space formed between the power electronic components is lower than the power electronic component on the center side.

  As a result, the bus bar is bent and deformed, and the power electronic components at both ends in the longitudinal direction of the bus bar are subjected to stress in a direction away from the heat radiating member by the bus bar. Stress in the pressing direction is applied.

  In this way, since a strong pressing force is applied to the power electronic component on the center side in the longitudinal direction from both sides, the thermal resistance between the power electronic component and the heat dissipation member can be favorably reduced. Instead, a force in the direction away from the heat dissipation member acts on the power electronic components at both ends in the longitudinal direction of the bus bar due to elastic deformation of the bus bar, but this force has a small height on the center side in the longitudinal direction of the bus bar. Since the power electronic component is smaller than the case where the power electronic component is provided, the deterioration of heat dissipation can be relatively reduced.

  That is, when a power electronic component with a small height is provided on the center side in the longitudinal direction of the bus bar, the bus bar is supported at both ends by two power electronic components with a high height and applies a large elastic force to the power electronic component on the center side. In the case where power electronic components having a small height are provided at both ends in the longitudinal direction of the bus bar, the bus bar is supported by one power electronic component having a high height on the center side and is provided on each of the two power electronic components on both ends. A small elastic force (direction away from the heat radiating member) is applied, and the power electronic components on both ends are opposed to the heat radiating member by the force to fasten the power electronic components and the heat radiating members on both ends sufficiently well. Can be secured.

  In a preferred aspect, a power electronic component that generates a larger amount of heat than the power electronic components on both ends in the longitudinal direction of the bus bar is disposed on the center side of the bus bar. That is, as described above, the power electronic component on the center side is strongly pressed against the heat radiating member by the bus bar, and therefore has a heat dissipation performance per unit area that is relatively superior to the power electronic components on both ends. For this reason, it is possible to suppress the temperature increase by disposing the power electronic component having a relatively large heat generation (or temperature increase is not preferable) on the center side relative to both ends.

In a preferred aspect, the bus bar is fastened to the power electronic component while avoiding a heat dissipating member fastening space that is a space set above a fastening portion of the plurality of power electronic components and the heat dissipating member. It is characterized by that.

  That is, in this invention, each power electronic component of the component assembly formed by previously fastening each power electronic component to the bus bar can be fastened to the heat dissipation member without being obstructed by the bus bar. More specifically, each power electronic component is fastened by a fastening tool that is inserted in the vertical direction through a heat dissipating member fastening space secured on the side of the bus bar.

  For this reason, the process of fastening each power electronic component individually to a heat radiating member can be omitted. That is, by connecting each power electronic component to the bus bar, the relative spatial position between each power electronic component is determined, so the position of each power electronic component and the heat radiating member can be determined simply by aligning the bus bar and the heat radiating member. Can be determined. Moreover, the process of fastening each power electronic component to a heat radiating member can be performed collectively, and fastening work can be simplified.

  In a preferred aspect, a first step of fastening the bus bar to each power electronic component to form a subassembly, a second step of setting the subassembly at a predetermined position above the heat radiating member, and thereafter And a third step of fastening the power electronic components of the subassembly to the heat dissipating member.

  That is, according to this assembling method, as described above, it is possible to simplify the alignment operation of each power electronic component connected to the bus bar to the heat radiating member, and it is possible to reduce the assembling cost and the assembling time.

  In a preferred aspect, a jig for determining a component position for setting each power electronic component before being fastened to the bus bar at a relative position between the power electronic components is prepared. After the electronic component is set on the jig and the relative position between the power electronic components is determined in advance, the bus bar is fastened to the power electronic component.

  That is, according to this aspect, the setting of the relative position between each power electronic component performed before fastening each power electronic component to the bus bar can be fitted into each power electronic component in a plane parallel to the main surface of the heat dissipation member. Since this is performed using a jig for determining the position of the component made up of a frame material having an appropriate hole, the relative positioning operation between the power electronic components can be performed very easily. Furthermore, if the bus bar is fastened to each power electronic component in a state where each power electronic component is set on the frame member, each power electronic component can be held at the time of the fastening work, and thus the assembly work is further simplified. Can be realized.

  After all, the present invention simplifies the fastening work of the heat dissipation member to each power electronic component by using the bus bar connected type electronic circuit device that holds the relative position between the power electronic components after the fastening. It is to be.

  Preferred embodiments of the bus bar connection type electronic circuit device of the present invention will be described with reference to the following embodiments. In addition, this invention is not limited to the following embodiment, Of course, this invention may be implemented by the combination of other well-known techniques. In the following description, it should be noted that the vertical direction is merely set for convenience.

(Embodiment 1)
The bus bar connection type electronic circuit device according to the first embodiment will be described below with reference to FIG.

  1 is a metal case, 2 to 4 are power electronic components, 5 is a bus bar, 6 to 9 are bolts for fastening components, and 10 to 13 are bolts for fastening bus bars. The metal case 1 is formed by, for example, pressing an aluminum alloy thick plate by pressing or the like, and has an upper end opened. Power electronic components 2 to 4 are fastened to the bottom surface 1 </ b> A of the metal case 1 by bolts 6 to 9. The power electronic components 2 to 4 are configured by electronic components that consume a large amount of power, such as power semiconductor switching element modules, transformers, power capacitors, and reactors. The bus bar 5 is formed by cutting a resin-coated copper plate into a predetermined shape, and is fastened with bolts 10 to 13 to a terminal portion (not shown) having a female screw hole provided on the upper surface of the power electronic components 2 to 4. Has been. In this embodiment, the bus bar 5 is a long plate parallel to the bottom surface 1A of the flat metal case 1 before assembly. The power electronic components 2 to 4 are arranged in the longitudinal direction of the bus bar 5, the height of the power electronic component 2 on the left end side is L2, the height of the power electronic component 4 on the center side is L1, and the power electronic component on the right end side The height of 3 is L3.

  The feature of this embodiment is that the height L1 of the power electronic component 4 on the center side is equal to the heights L2 and L3 of the power electronic components 2 and 3 on both ends, including manufacturing tolerances, or higher than the predetermined amount α. It is in the set point. The predetermined amount α is determined in accordance with the elastic deformation force of the bus bar 5, and preferably 0.5 to 5 mm. As a result, at the position of the power electronic component 4 on the center side, a space having a height of approximately (L2 + L3) / 2 between the lower surface of the bus bar 5 and the bottom surface of the metal case 1 (component installation space referred to in the present invention). Lx is formed.

  In this way, the following effects can be obtained. As shown in FIG. 1, a gap is generated between the power electronic components 2 and 3 and the bottom surface of the metal case 1 before the bolts 10 to 14 are fastened. Is eliminated by deformation toward the bottom surface 1 </ b> A side of the metal case 1. The elastic deformation of the deformation of the bus bar 5 presses the power electronic component 4 on the center side against the bottom surface 1A side of the metal case 1, and heat between the power electronic component 4 on the center side and the bottom surface 1A of the metal case 1 is heated. Reduce resistance. On the contrary, the bottom surfaces of the power electronic components 2 and 3 on both ends tend to be separated from the bottom surface 1A of the metal case 1 by the elastic deformation of the bus bar 5, but the force is applied to the two power electronic components 2 and 3 Since the force applied to one power electronic component is reduced when dispersed, the bolts 6 to 9 are opposed to this force even if a large bolt 6-9 is not used. Can be satisfactorily fastened to the bottom surface 1 </ b> A of the metal case 1. Moreover, the rotational torque for fastening each bolt 6-9 may be small.

  This means that when the power electronic components 2 and 3 on both ends are assembled to the bus bar 5 and the metal case 1, the height of the space (component installation space referred to in the present invention) generated at the position of the central power electronic component ( L2 + L3) / 2 is equal to or higher than the height L2 and L3 of the power electronic components 2 and 3 on both ends because the height L1 of the central power electronic component 4 installed in the component installation space is equal to or higher than the height L2 and L3. The power electronic component 4 becomes smaller than the height L1. In other words, the height L1 of the central power electronic component 4 is higher than the component installation space (L2 + L3) / 2. For this reason, when the power electronic components 2 to 4 are assembled to the bottom surface of the metal case 1, both end portions of the bus bar 5 are deformed by a height difference (L1− (L2 + L3) / 2). Normally, it is considered that there is plastic deformation and elastic deformation in this deformation, but the force in the peeling direction due to this elastic deformation is distributed and applied to the power electronic components 2 and 3 on both end sides. That adverse effect is reduced. In the above description, bending deformation of the bottom plate portion of the metal case 1 is not considered.

  In this embodiment, as the power electronic component 4 on the center side, a power electronic component larger than the power consumption of the power electronic components 2 and 3 on both ends or a power electronic component having a lower allowable temperature is adopted. As a result, a relatively strong cooling effect required for the central power electronic component 4 can be easily realized.

  In addition, you may arrange | position interposed members, such as an electrical insulation sheet, between the power electronic components 2-4 and the bottom face 1A of the metal case 1, and in this case, the height of the power electronic components 2-4 is these interposed. It should be calculated including the members.

(Modification)
The bus bar connection type electronic circuit device of FIG. 2 is the same as that of the device of FIG. 1, of the bottom surface 1 </ b> A of the metal case 1. A level difference higher than the surface by L4 is provided on the bottom surface 1A of the metal case 1. In this case, if this step height L4 is included as the height of the power electronic component 4, it is clear that the same relationship as in the first embodiment is established.

(Modification)
The bus bar connection type electronic circuit device of FIG. 3 is the same as that of the device of FIG. 1, but the mounting surface of the power electronic component 4 on the center side of the bottom surface 1A of the metal case 1 is mounted on the power electronic components 2 and 3 on both ends. A groove which is lower than the surface by L4 is provided on the bottom surface 1A of the metal case 1. In this case, if the step height L4 is subtracted as the height of the power electronic component 4, it is clear that the same relationship as in the first embodiment is established.

(Modification)
The bus bar connection type electronic circuit device of FIG. 4 further includes the mounting surface of the power electronic component 3 on the right end side of the bottom surface 1A of the metal case 1 in the device of FIG. A level difference higher than the placement surface by L5 is provided on the bottom surface 1A of the metal case 1. Also in this case, it is obvious that the same relationship as in the first embodiment is established if the step height L5 is included as the height of the power electronic component 5.

(Modification)
The bus bar connection type electronic circuit device of FIG. 5 further includes the mounting surface of the power electronic component 3 on the right end side of the bottom surface 1A of the metal case 1 in the device of FIG. A groove that is lower than the placement surface by L5 is provided on the bottom surface 1A of the metal case 1. Also in this case, it is obvious that the same relationship as in the first embodiment is established by subtracting the step height L5 as the height of the power electronic component 5.

(Modification)
The bus bar connection type electronic circuit device of FIG. 6 further includes the bus bar 5 of the power electronic components 2 and 3 on both ends of the bus bar 5 with the height of the connection portion with the power electronic component 4 on the center side. Is higher than the height of the connecting part by ΔL (not shown). In this case, it is obvious that the same relationship as in the first embodiment is established by subtracting the bus bar step ΔL from the height L1 of the power electronic component 4.

(Explanation of assembly process)
Next, the assembly process of this apparatus will be described with reference to FIGS.

  FIG. 7 shows a process of assembling the bus bar 5 to each power electronic component 2-4.

  Reference numeral 14 denotes a component position determining jig that determines a relative position between the power electronic components 2 to 4 and holds the power electronic components 2 to 4 while securing the relative position. The jig 14 is preferably a perforated metal plate. That is, the jig 14 has a component holding groove portion having flat upper surfaces 15 to 17 in which the bottom surfaces of the power electronic components 2 to 4 are in close contact and side surfaces 18 to 22 in close contact with the side surfaces of the power electronic components 2 to 4. 23 to 25. In order to facilitate setting (lowering) of the power electronic components 2 to 4 in the component holding groove portions 23 to 25, a taper is formed on the upper peripheral edges of the component holding groove portions 23 to 25.

  In this embodiment, as shown in FIG. 7, the jig 14 is provided with a through hole (may be a groove) surrounding the tip portions of the bolts 6 to 9. As a result, the power electronic components 2 to 4 can be individually set in the component holding groove portions 23 to 25 of the jig 14 with the bolts 6 to 9 being set in advance to the power electronic components 2 to 4. .

  After each power electronic component 2-4 is lowered and set in each component holding groove 23-25 of the jig 14, the bus bar 5 is moved to the space above the jig 14, and then the bus bar 5 is attached to the jig 14. On the other hand, it is set at a predetermined position in the horizontal direction. Thereby, since the female screw holes 26-29 of the terminal part of each power electronic component 2-4 and the through-holes 30-33 of the bus-bar 5 can be aligned, bolts 10-14 are used using a bolt fastening tool. The fastening between the bus bar 5 and each power electronic component 2 to 4 is completed.

  Next, the jig 14 is separated from the power electronic components 2 to 4, and the assembly 34 including the power electronic components 2 to 4 and the bus bar 5 is moved above the metal case 1 shown in FIG. The horizontal alignment with the metal case 1 is performed, and then the bolts 6 to 9 are fastened.

  What is important here is that, on the side of the bus bar 5, the bolt fastening tool for fastening the bolts 6 to 9 descends from above to the position for fastening the bolts 6 to 9, and rises again after the fastening is completed. The work space (space for fastening the heat radiation member) is secured. That is, in this embodiment, it is prohibited to arrange the bus bar 5 in the heat dissipating member fastening space. Thereby, it becomes possible to assemble a large number of the above-mentioned power electronic components to the bus bar and the metal case very easily. The planar shape of the bus bar is shown in FIG.

  In this embodiment, the metal case 1 is adopted as the heat radiating member of each of the power electronic components 2 to 4. However, it is obvious that a flat metal heat radiating plate may be used.

1 is a longitudinal sectional view showing an electronic circuit device of Example 1. FIG. It is a longitudinal cross-sectional view which shows the electronic circuit apparatus of a deformation | transformation aspect. It is a longitudinal cross-sectional view which shows the electronic circuit apparatus of a deformation | transformation aspect. It is a longitudinal cross-sectional view which shows the electronic circuit apparatus of a deformation | transformation aspect. It is a longitudinal cross-sectional view which shows the electronic circuit apparatus of a deformation | transformation aspect. It is a longitudinal cross-sectional view which shows the electronic circuit apparatus of a deformation | transformation aspect. It is a longitudinal cross-sectional view which shows the assembly | attachment process of the electronic circuit device of FIG. It is a longitudinal cross-sectional view which shows the assembly | attachment process of the electronic circuit device of FIG. It is a principal part top view of the electronic circuit device of FIG. It is a longitudinal cross-sectional view which shows the assembly | attachment process of the conventional electronic circuit device. It is a longitudinal cross-sectional view which shows the assembly | attachment process of the conventional electronic circuit device. It is a longitudinal cross-sectional view which shows the assembly | attachment process of the conventional electronic circuit device.

Explanation of symbols

  1 is a metal case, 2 to 4 are power electronic components, 5 is a bus bar, 6 to 9 are bolts for fastening components, 10 to 13 are bolts for fastening bus bars, 14 is a jig for determining the position of components, 23 to 25 Are the component holding groove portions 23 to 25.

Claims (5)

Multiple power electronic components,
Each of the power electronic components is a metal heat dissipating member fastened to the upper surface,
A bus bar that is fastened to a terminal portion on the upper surface of each power electronic component and electrically connects each power electronic component;
With
In the bus bar connection type electronic circuit device, the fastening portion of at least the power electronic component of the bus bar is arranged substantially parallel to a portion of the upper surface of the heat dissipation member that contacts at least the bottom surface of the power electronic component.
When the two power electronic components on both ends of the three or more power electronic components arranged in the longitudinal direction of the common bus bar are attached to the heat dissipating member and the bus bar, the power electronics on the center side The height of the component installation space, which is a space generated between the heat dissipation member and the bus bar at the component installation position, is set lower than the height of the power electronic component on the center side provided in the component installation space. A bus bar connection type electronic circuit device. The bus bar connection type electronic circuit device according to claim 1,
A bus bar connection type electronic circuit device in which power electronic components that generate more heat than the power electronic components at both ends in the longitudinal direction of the bus bar are arranged on the center side of the bus bar. The bus bar connection type electronic circuit device according to claim 1,
The bus bar is fastened to the power electronic component while avoiding a heat dissipating member fastening space which is a space set above a fastening portion between the plurality of power electronic components and the heat dissipating member. Busbar connection type electronic circuit device. In the assembly method of the bus bar connection type electronic circuit device according to claim 3,
A first step of forming a subassembly by fastening the bus bar to each of the power electronic components;
A second step of setting the subassembly at a predetermined position above the heat dissipating member;
Thereafter, a third step of fastening the power electronic components of the subassembly to the heat dissipation member;
A method of assembling a bus bar-connected electronic circuit device, comprising: In the assembly method of the bus bar connection type electronic circuit device according to claim 4,
Prepare a jig for component position determination to set each power electronic component before fastening to the bus bar at a relative position between the power electronic components,
The first step includes
A bus bar connection type electronic circuit device comprising: setting each power electronic component on the jig and preliminarily determining a relative position between the power electronic components; and fastening the bus bar to the power electronic component. Assembly method.

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