JP3508521B2 - Power module terminal connector and terminal connection method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power module used in a motor control device in an electrically driven vehicle, and a power module terminal connecting tool and a terminal connecting method for preventing heating due to poor terminal connection. Regarding

[0002]

2. Description of the Related Art Conventionally, in a motor control device used in an electric motor driven vehicle such as a battery or forklift, a battery switching device for directly supplying electric power to a main motor for traveling is provided at the final stage of a control circuit. Especially, a power module having a large electric capacity is used. A power module is one in which a plurality of power semiconductor chips are incorporated in one resin package, the same chips are simply incorporated in parallel to increase the current capacity, and some types of chips constitute a simple circuit. There are various internal configurations such as those with built-in power chip drive circuits. The package is usually made of plastic, the semiconductor chip inside is insulated by ceramics, etc. Further, the cavity inside the package is filled with gel and epoxy resin from below to prevent oxidation of the chip peripheral circuit.

In addition, since the power module handles a large current due to the nature of its application, it generates a large amount of heat, and therefore is installed on a substrate having a large heat capacity and a high heat dissipation effect (high thermal conductivity), and heat is dissipated from the heat dissipation substrate inside the package. Is performed.

FIG. 4 is a view for explaining the external appearance of the package of the power module 1 generally used in an electrically driven vehicle and the like and the structure of the external terminal 2 portion. As shown in this figure, the module package 1 has a substantially rectangular parallelepiped shape, while the external terminals 2 have terminals that vertically project from the terminal openings 3 formed on the upper surface of the module package 1 when the module package 1 is assembled and manufactured. 3 is bent at a right angle from the root near 3 (arrow A), and the upper and lower surfaces are stopped by the nut 4 and the screw 10 for fixing the connection bar 6 (see FIG. 6). Here, since the nut 4 is simply loosely fitted in the hole formed in the upper surface of the package 1 in the same shape, the external terminal 2 itself has no mechanical restraint.

Also, in the circuit configuration of the motor control device, the method of increasing the current capacity by connecting a plurality of the same power modules 1 in parallel is often used, so that the connection bar 6 which is a conductor is used. Parallel connection between all external terminals 2 is often implemented. In this case, the connection bar 6 is joined to the upper surface of the bent external terminal 2 by screwing after contacting it with a sufficient area in consideration of conduction of a large current.

[0006]

However, according to the structure of the external terminal 2 of the module package 1 described above, when the external terminal 2 is bent during assembly and manufacturing, no matter how well the external terminal 2 is bent, the elasticity of the external terminal 2 itself causes the bending. As a result, a certain amount of rebound was generated as shown in FIG.

As described above, the package 1 of the power module is filled with gel and epoxy resin up to the vicinity of the terminal port 3 to prevent oxidation of the internal circuit, so that it extends from the internal circuit to the outside of the package 1. External terminal 2
Is firmly fixed in the vicinity of the external terminal port 3 in the package 1, and there is almost no play during bending.

When the connection bar 6 is joined by the screw stopper as described above in this state, the external terminal 2 is bent in a "V" shape as shown by an arrow B in FIG. The external terminal 2 and the connection bar 6 were in a state of being joined to each other without obtaining a sufficient contact area as specified.

However, taking the case of use in a large-sized battery / forklift as an example, the drive current of the traveling motor flowing in the power module becomes a large current of 500 A or more at the maximum, and it is bent into the "C" shape as described above. Since the external terminals that are not bent properly are not connected to the connection bar 6 due to the design, an area sufficient to withstand the passage of the large current cannot be obtained, so that an electric resistance component is generated at the contact portion. However, this resulted in an increase in heat generation. This (high) heat is accumulated inside the power module, which causes damage to the internal circuit.

Therefore, in order to prevent damage resulting from improper bending of the external terminal, the bent portion is inspected after connecting the connecting bar to the external terminal, and if the gap is wide, the connecting bar is opened. It took a lot of time to remove it, correct the bending of the terminal, and then reconnect it. However, if this external terminal is repeatedly bent and reconnected by screwing, some mechanical damage to the fixing screw and both terminals is unavoidable, which also affects the electrical connection between the two terminals. According to the above, heat generation and circuit damage were caused.

In view of the above-mentioned conventional problems, the present invention prevents the internal circuit from being damaged by heat generation, and thus enables a terminal for a power module which enables a sufficient contact area between both terminals to be obtained by a single connection. An object is to provide a connecting tool and a terminal connecting method using the connecting tool.

[0012]

The structure of a power module terminal connector according to the present invention and a power module terminal connecting method using the same will be described below.

First, the invention according to claim 1 relates to a terminal connecting tool for a power module for connecting terminals by screwing. When the connecting bar is completely screwed, the power module of the connecting bar is provided. The connection bar support having a shape for supporting the connection bar such that the lower plane of the terminal connection portion is at the same height as the upper plane of the power module terminal in the normal bending state, and the connection bar support are installed. Connection bar support fixing means for fixing to the board, screwing means for connecting and fixing the connection bar to the power module terminal, and screwing means for fixing the connection bar to the connection bar support To be done.

Next, the invention of claim 3 is the same as claim 1
The present invention relates to a method for connecting a power module terminal using the terminal connecting device described above, pressing the power module terminal by first screwing the connection bar to the connection bar support,
After that, the terminal connection method is performed by the procedure of screwing the connection bar to the power module terminal.

According to the above two inventions, in order to secure a sufficient contact area between both terminals in the related art, it is possible to accurately and accurately perform the terminal connection which is repeatedly performed while correcting the bending of the external terminal. Thus, it becomes possible to easily implement the terminal connection capable of preventing the heating caused by the poor contact between the terminals.

In the invention according to claim 1, for example, as in claim 2, the material of the bar support is made of a metal (aluminum or the like) having a high thermal conductivity, and the bar support fixing means is , A heat conductive insulating sheet sandwiched between the substrate and the bar support. With this, heat generated from the connection bar due to conduction of a large current is radiated to the installation board (and the body frame, etc. on which the installation board is installed) having a large heat capacity through the connection bar support while maintaining electrical insulation. Is possible.

According to a fourth aspect of the present invention, in a terminal connector for a power module in which terminals are connected by screwing, it is a conductor, has a rigidity higher than that of the power module terminal, and is screwed to a substrate to be installed. And a terminal connection body having a shape in which a lower plane of the power module terminal connection portion is at the same height as an upper plane of the power module terminal in a properly bent state when completely fixed. Terminal connecting body fixing means for fixing the terminal connecting body to the substrate on which the terminal connecting body is installed, and the terminal connecting body is connected and fixed to the power module terminal. It is composed of screwing means.

With this configuration, the connection bar and the connection bar support are integrally formed separately from the structure of the invention according to claims 1 and 3, so that the number of parts and the number of steps at the time of construction can be reduced. Therefore, cost and construction errors can be reduced.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view illustrating an embodiment of a power module terminal connector and a terminal connecting method using the same according to the present invention. In this embodiment, an example in which the same two power modules 1 and 1'are arranged in parallel with the connection bar support 7 interposed therebetween and the same terminals are connected in parallel by the connection bar 6 will be described. In addition, in the present embodiment, the connection bar support 7 described above is used.
Is an aluminum block, the installation board 8 is also an aluminum plate, and the connection bar 6 is an aluminum block 7 and an external terminal 2.
The connection bar screw fixing screws which are respectively fixed to the support screw 9 and the external terminal screw 10,
10 ', and other connecting bar screwing means are spring washers 11, 11', flat washers 12, 12 'and nuts (not shown), and the connecting bar support fixing means mounts the aluminum block 7 on the installation substrate 8. It consists of a fixing screw, a nut, an insulating spacer (the above three points are not shown), and a heat conductive insulating sheet 13.

First, FIG. 2 (a) illustrates the arrangement of the power modules 1, 1 ', the connection bar 6 and the connection bar support 7 according to the present invention immediately before connecting the connection bar 6 to the external terminal 2 of the power module. In the figure, the same two power modules 1 and 1 ′ are installed in parallel on an installation substrate 8 with an aluminum block 7 interposed therebetween. The power modules 1, 1'are directly fixed on the installation board 8 by screws 5, 5'at both ends of the package, while the aluminum block 7 has a heat conductive insulating sheet 13 sandwiched between it and the installation board 8. The aluminum block 7 and the installation board 8 are firmly fixed by a screw and a nut (not shown) so as to penetrate vertically. At this point, the height of the upper plane of the aluminum block 7 is the same as the height of the upper plane when the external terminals 2 of the power module are in a regular flat bent state. In addition, an insulating spacer is narrowly provided between the screw fixing the aluminum block 7 and the aluminum block 7 to electrically insulate the installation board 8 also made of aluminum. (Shown).

The screws 5, 5'for fixing the power modules 1, 1'to the installation board 8 and the screw 9 for fixing the connection bar 6 to the aluminum block 7 are attached to the installation board 8 and the aluminum block 7 respectively. It will be stopped by the cut female screw (not shown). And connection bar 6
Is in contact with the upper ends of the external terminals 2 in the rebounded state of the power modules 1, 1 ′ described above, the screw 9
It is stopped by the aluminum block 7.

The essential point of the terminal connecting method of the present invention starting from the state shown in FIG. 2 (a) is that the connecting bar 6 and the aluminum block 7 are slowly stopped by the screw 9 so that the external terminal 2 of the power module is at the same time. It is about bending.

According to this method, since the external terminal 2 is not bent directly by tightening the screw, the external terminal 2 has a degree of freedom in the lateral direction in this figure, and then the connecting bar 6 raises it. As a result, it can be bent so that it is pressed down comfortably (arrow F).

Finally, when the connecting bar 6 is completely stopped on the upper surface of the aluminum block 7, the external terminal 2 is in a regular bent state in which a contact area sufficient for conducting a large current by design is secured. In this case (Fig. 2 (b)), the connection bar 6 and the connection bar 6 can be stopped by the screws 10, 10 '(Fig. 2 (c)).

Here, the connection bar 6 used in the connection method of the present invention needs to have a high rigidity enough to bend the external terminal 2 of the power module in this manner. Here, the high rigidity refers to a material mechanical ability that enables bending of the power module terminal by combining material hardness and a size such as thickness and width as a member. Also, the spring washers 11, 11 'and the flat washers 1
2, 12 'maintains the screwing tension of the external terminal screws 10, 10' with respect to the connecting bar 6, and at the same time efficiently disperses the screwing stress, so that it is strongly fixed against external factors such as vibration. Is possible.

Further, since the connection bar support 7 in this embodiment is made of aluminum having a high thermal conductivity as a base material, the connection bar support 7 is generated at the joint between the external terminal 2 and the connection bar 6 when a large current is conducted. The high heat generated is radiated to the aluminum installation board 8 through the aluminum connection bar support 7 and the heat conductive insulating sheet 13. However, the insulating spacer and the insulating sheet 13 described above ensure electrical insulation between the connection bar support 7 and the installation substrate 8. Further, the connection bar support 7 is not limited to the form of the aluminum block described above, and a pillar-shaped configuration using another metal or an insulator as a base material is also possible. However, when this insulating support body is used for the connection bar support body 7, the heat dissipation effect in the form of the aluminum block described above cannot be expected. Also in this case, the height of the lower plane at the power module terminal connection portion of the connection bar is set to the external terminal 2 of the power module when the connection bar is installed on the installation substrate 8 and the connection bar is screwed. Is configured to match the height of the upper plane when it is in a normal bend.

Further, although the connecting bar 6 has a straight shape in the present embodiment, it is not necessarily limited to such a shape. For example, the height of the aluminum block 7 in FIG. Even if the connecting bar 6 is made higher (lower) than that, if the central portion of the connecting bar 6 is formed in a convex shape (concave shape) accordingly, the desired action can be obtained. It is also possible to combine the shapes of the aluminum block 7 and the aluminum block 7.

FIG. 3 is a view for explaining another embodiment of the power module terminal connector according to the present invention. In this figure, the difference from the embodiment is that the connection bar 6 and the connection bar support 7 are integrally formed as a terminal connection body 14, and the connection bar and the connection bar support are fixed. No need for screws and washers
Further, the step of screwing the connection bar to the connection bar support is also unnecessary. That is, the bending of the external terminal 2 of the power module described above is performed at the same time when the terminal connection body 14 is fixedly installed on the installation board 8.

Thus, in addition to the structure of the above-mentioned embodiment, the connection bar 6 and the connection bar support 7 are integrally formed, so that the number of parts and the number of steps at the time of construction can be reduced. Reduction will be achieved.

Further, in the embodiment of the present invention, the same two power modules are arranged in parallel so as to sandwich one connection bar support, and the same terminals are connected to each other by the connection bar. The present invention is not limited to this form, and one connection bar support is installed in one power module, or one power module is installed in parallel so as to be sandwiched by two connection bar supports. Also, a configuration in which three or more power modules are connected in parallel is possible to further increase the electric capacity. Also in this case, the connection bar is screwed in the order in which the connection bar support is first screwed.

[0031]

As described above in detail, according to the present invention, the power module, which has conventionally been subjected to repeated bending correction of the external terminals, can be easily carried out at one time. Since it is possible to prevent the disposal of parts due to damage to the construction, the construction cost can be reduced.

Further, since a sufficient contact area can be secured between both terminals, a high current can be suppressed and heat can be handled stably, improving the performance and prolonging the life of the power module (internal circuit), and eventually the motor and It is effective in improving battery performance and extending battery life.

[Brief description of drawings]

FIG. 1 is a terminal connector for a power module according to the present invention,
It is a side view explaining one embodiment of a terminal connecting method using it.

2A is a view immediately before connecting the connection bar to an external terminal, FIG. 2B is a view when the connection bar is cut off in an aluminum block, and FIG. 2C is a view when the connection bar is connected to an external terminal.
It is a figure explaining arrangement and connection of parts.

FIG. 3 is a diagram for explaining another embodiment of the power module terminal connector according to the present invention.

FIG. 4 is a diagram illustrating an appearance of a package of a power module generally used in an electrically driven vehicle or the like and a configuration of an external terminal portion.

FIG. 5 is a diagram illustrating a rebound that occurs in an external terminal of a power module.

[Fig. 6] "KU" of an external terminal produced by a conventional connection method
It is a figure explaining bending of a character shape.

[Explanation of symbols]

1, 1'Power module (package) 2, 2'external terminals 4 nuts 5, 5'screw 6 connection bar 7 Connection bar support (aluminum block) 8 installation boards 9 Support screw 10, 10 'External terminal screw 13 Thermally conductive insulation sheet 14 terminal connection

Claims (4)

(57) [Claims] 1. A terminal connector for a power module for connecting terminals by screwing, comprising: a connecting bar having rigidity higher than that of a power module terminal, which is a conductor; and the connecting bar when the connecting bar is completely screwed. The lower plane of the power module terminal connection part of the bar is
A connection bar support having a shape for supporting the connection bar so as to be at the same height as the upper plane of the power module terminal in a regular bent state, and the connection bar support is fixed to a substrate to be installed. Connection bar support fixing means, screwing means for connecting and fixing the connection bar to the power module terminal, and screwing means for fixing the connection bar to the connection bar support body, Power module terminal connector. 2. The bar supporting body is made of a heat conductive metal, and the bar supporting body fixing means has a heat conductive insulating member that is sandwiched between the substrate and the bar supporting body. The terminal connector for a power module according to claim 1. 3. The power module terminal connecting method using the terminal connecting device according to claim 1, wherein the power module terminal is pressed by first screwing the connection bar to the connection bar support, and then the connection bar. Is connected to the power module terminal with a screw. 4. A terminal connector for a power module, wherein terminals are connected by screwing, which is a conductor and has a rigidity higher than that of the power module terminal, and is fixed to a substrate to be installed by screwing.
A lower surface of the power module terminal connecting portion has a shape such that the lower surface has the same height as the upper surface of the power module terminal in a normally bent state, and the terminal connecting body and the board to be installed are tightly attached. A terminal connecting body fixing means for fixing the terminal connecting body to the substrate on which the terminal connecting body is installed; and a screwing means for connecting and fixing the terminal connecting body to the power module terminal. A terminal connector for a power module, which is characterized in that