JP7084294B2 - Capacitor terminal - Google Patents

Description

The present invention relates to a capacitor terminal that connects a substrate and a capacitor by soldering a bus bar on the capacitor side.

A capacitor module in which a plurality of capacitors and a substrate for discharge control are housed in a resin case and the capacitors and the substrate are connected to each other via a bus bar is known (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-032831

As a structure for connecting the capacitor and the board, a structure in which the terminal on the board side and the bus bar on the capacitor side are connected by soldering may be adopted. In that case, if the terminals on the substrate side are provided so as to protrude from the resin portion of the case or the like, solder may flow to the resin portion side, causing problems such as carbonization or deformation of the resin portion.

Therefore, an object of the present invention is to provide a capacitor terminal capable of suppressing or eliminating the influence of solder bonding on the resin portion existing near the terminal.

The capacitor terminal according to one aspect of the present invention is provided so that the substrate and the capacitor are connected via a bus bar and protrude from the resin portion on the substrate side separated by sandwiching the resin portion, and are provided on the capacitor side. It is a capacitor terminal that connects the substrate and the capacitor by soldering the bus bar, and is located between the junction hole that is the target location of the solder junction and between the junction hole and the resin portion. Moreover, the slit extending along the width direction orthogonal to the protrusion direction from the resin portion is provided.

FIG. 3 is a plan view showing an example of a capacitor module provided with a signal terminal for a capacitor according to an embodiment of the present invention. The figure which shows the state which removed the substrate from the state of FIG. The figure which shows the part III of FIG. 1 enlarged. FIG. 3 is an enlarged perspective view showing the signal terminals of FIGS. 1 to 3 and their surroundings. The perspective view which shows the signal terminal of FIG. 4 further enlarged.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings. First, an example of a capacitor module provided with a capacitor terminal according to this embodiment will be described with reference to FIGS. 1 to 3. The capacitor module according to this embodiment is used for a power conversion device mounted on a vehicle such as an electric vehicle.

As shown in FIG. 1, the capacitor module 1 includes a plurality of capacitors 2, a discharge resistance substrate (hereinafter, abbreviated as a substrate) 3 for controlling the discharge of the capacitors 2, a positive electrode side of the capacitor 2, and the capacitor 2. It is provided with a pair of bus bars 4A and 4B for connecting each of the negative electrode sides and the substrate 3. In the following description, in order to distinguish the direction of the capacitor module 1, the direction in which the capacitor 2 and the substrate 3 are arranged is defined as the X direction, and the direction parallel to the paper surface of FIG. 1 and orthogonal to the X direction is defined as the Y direction. The direction orthogonal to the paper surface of FIG. 1 is defined as the Z direction. However, these definitions are for the purpose of distinguishing the direction of the capacitor module 1 for convenience of explanation, and have no technical significance. In FIG. 1, the capacitor 2 is arranged behind the bus bars 4A and 4B, and a part of them is visible.

The substrate 3 functions to forcibly discharge the electric charge stored in the capacitor 2 when, for example, the main switch of the vehicle is turned off. However, the function of the substrate is not limited to this, and a substrate having an appropriate function may be mounted on the capacitor module 1. Each of the buses 4A and 4B is provided with a plurality of external connection terminals 4a and 4b for connecting an external circuit or the like different from the capacitor module 1 and the capacitor 2 side by side in the X direction as an example. The external connection terminals 4a and 4b are extended in the Z direction as an example.

The capacitor 2, the substrate 3, and the bus bars 4A and 4B are housed in a resin case 5. As shown in FIG. 2, the case 5 is provided with a capacitor accommodating portion 5a in which the capacitor 2 is accommodated and a substrate accommodating portion 5b in which the substrate 3 is accommodated. The board accommodating portion 5b is provided with a pair of bus bars 6A and 6B for signal extraction. In the following, the words “capacitor side” may be added to the bus bars 4A and 4B, and the word “board side” may be added to the bus bars 6A and 6B to distinguish the bus bars. The bus bars 6A and 6B on the substrate side are arranged in the mold as insert parts at the time of molding the case 5, and are integrated with the case 5. The substrate 3 is attached to the case 5 so as to be appropriately connected to the bus bars 6A and 6B.

As an example of the capacitor terminal, each of the bus bars 6A and 6B on the board side is integrally provided with a signal terminal 7 for connecting to the bus bar 4 on the capacitor side. The case 5 is also provided with a pair of terminal pins 8 projecting in a direction different from the signal terminal 7 (for example, the Y direction). These terminal pins 8 are for connecting the substrate 3 and the external circuit.

As shown in FIG. 3, each signal terminal 7 is provided so as to project from the wall portion 5c separating the capacitor accommodating portion 5a and the substrate accommodating portion 5b of the case 5 toward the capacitor accommodating portion 5a. The protruding direction of the signal terminal 7 from the wall portion 5c substantially coincides with the X direction. The wall portion 5c corresponds to an example of the resin portion. Each of the signal terminals 7 is selectively connected to the bus bars 4A and 4B on the capacitor side by soldering. The connection is a mechanical and electrical connection. In FIG. 3, the solder joints are indicated by reference numerals Ps. When the assembly of various components such as the capacitor 2 and the substrate 3 is completed, the case 5 is further filled with resin and the components of the capacitor module 1 are molded.

As shown in FIGS. 4 and 5, the signal terminal 7 is provided with a joint hole 7a and a slit 7b located between the joint hole 7a and the wall portion 5c, in other words, on the root side of the signal terminal 7. There is. The joint hole 7a has an elongated hole shape formed so that its longitudinal direction is directed to the projecting direction (X direction) of the signal terminal 7 from the wall portion 5c, and the signal terminal 7 is formed in the thickness direction (X direction). It is provided as a through hole penetrating in the Z direction). As is clear from FIG. 3, the joint hole 7a is a portion to be soldered. That is, the solder bonding between the bus bars 4A and 4B on the capacitor side and the bus bars 6A and 6B on the substrate side is performed centering on the joint hole 7a. By extending the joint hole 7a along the projecting direction of the signal terminal 7, it is relatively easy to secure the joint hole 7a having a size required for soldering while suppressing a decrease in the cross-sectional area of the signal terminal 7.

On the other hand, the slit 7b has a long hole shape formed so that its longitudinal direction is oriented in the width direction (Y direction in the illustrated example) orthogonal to the protruding direction of the signal terminal 7, and the thickness of the signal terminal 7 is increased. It is provided as a through hole penetrating in the orthogonal direction. However, the longitudinal direction of the slit 7b does not necessarily have to exactly match the width direction of the signal terminal 7. The slit 7b may be slightly inclined with respect to the width direction of the signal terminal 7 at least in a part thereof. Alternatively, at least a part of the slit 7b may be accompanied by a curve. In any case, the slit 7b may have a shape extending along the width direction of the signal terminal 7 when viewed from the whole.

The total length of the slit 7b in the width direction of the signal terminal 7 may be set in association with the current value flowing through the signal terminal 7. When the slit 7b is provided, the cross-sectional area of the signal terminal 7 decreases at the position of the slit 7b. On the other hand, the cross-sectional area of the signal terminal 7 correlates with the maximum value of the current that can flow through the signal terminal 7, and the smaller the cross-sectional area, the lower the maximum value of the current that can flow. therefore,
Assuming the maximum value of the current passing through the signal terminal 7, the minimum value of the cross-sectional area required to pass the maximum current is calculated, and the total length of the slit 7b is within the range where the cross-sectional area equal to or larger than the minimum value is secured. It is appropriate to determine.

The joint holes 7a and slits 7b of the signal terminal 7 may be formed at the same time when the bus bars 6A and 6B are manufactured, respectively. For example, when each of the bus bars 6A and 6B is manufactured by punching from a metal plate, it is possible to simultaneously form the signal terminal 7 including the joint hole 7a and the slit 7b by the punching.

According to the above signal terminal 7, a slit 7b is provided so as to extend along the width direction of the signal terminal 7 between the joint hole 7a to be the target portion of soldering and the resin wall portion 5c. Therefore, even if the solder flows to the wall portion 5c side at the time of soldering, the flow can be blocked by the slit 7b and the solder can be prevented from reaching the wall portion 5c. Further, by providing the slit 7b, the cross-sectional area of the signal terminal 7 at the position of the slit 7b is reduced, so that the influence of heat shrinkage at the time of solder joining on the wall portion 5c can be reduced. Thereby, it is possible to suppress or eliminate the influence of the solder joint on the wall portion 5c. Further, since the slit 7b can be formed at the same time when the signal terminal 7 is manufactured and when the bus bars 6A and 6B on the substrate side are manufactured, it is not necessary to add a separate step for forming the slit 7b. This makes it possible to reduce costs. Moreover, since the outer peripheral shape of the signal terminal 7 may be the same regardless of the presence or absence of the slit 7b, there is no possibility that the arrangement of other parts around the signal terminal 7 will be affected.

The present invention is not limited to the above-mentioned form, and may be carried out in various modified or modified forms. For example, in the above embodiment, the protruding direction of the signal terminal 7 from the wall portion 5c as an example of the capacitor terminal is set to the arrangement direction (X direction) of the capacitor 2 and the substrate 3, but the protruding direction of the capacitor terminal. May be appropriately changed as long as it is suitable for the connection between the bus bar on the capacitor side and the board. The capacitor terminal is not limited to the example in which it is integrally formed with the bus bars 6A and 6B on the board side, and is provided in an appropriate manner as long as it can be used for connecting the capacitor to the board by interposing between the board and the bus bar on the capacitor side. It may be provided.

The embodiments of the present invention derived from the above-described embodiments and modifications will be described below. In the following, reference numerals in the drawings are added in parentheses, but the embodiment of the present invention is not limited to the illustrated form.

In the capacitor terminal (7) according to one aspect of the present invention, the substrate (3) and the capacitor (2) are connected via a bus bar (4A, 4B) and are separated by a resin portion (5c). The substrate (3) and the capacitor (2) are provided so as to protrude from the resin portion (5c) on the substrate (3) side, and the bus bars (4A, 4B) on the capacitor (2) side are solder-bonded to the substrate (3). ), Which is a terminal for a capacitor and is located between the joint hole (7a) which is the target portion of the solder joint and the joint hole and the resin portion, and is in the protruding direction from the resin portion (). It is provided with a slit (7b) extended along a width direction (for example, the Y direction) orthogonal to the X direction (for example).

According to the above aspect, even if the solder flows to the resin portion side at the time of solder joining, the flow can be blocked by the slit to prevent the solder from reaching the resin portion. Further, by reducing the cross-sectional area of the capacitor terminal at the position of the slit, it is possible to reduce the influence of heat shrinkage generated at the time of solder joining on the resin portion. By these actions, it is possible to suppress or eliminate the influence of the solder bonding on the resin portion existing near the terminal. Moreover, since the outer peripheral shape of the capacitor terminal does not change even if the slit is provided, there is no possibility that the arrangement of other parts around the capacitor terminal is affected.

In the above aspect, the junction hole may have a shape extended along the protruding direction of the capacitor terminal. In this case, it is possible to relatively easily provide a joint hole having a size required for soldering while ensuring the cross-sectional area of the capacitor terminal. Further, the capacitor terminal may be integrally formed with the board-side bus bar (6A, 6B) interposed between the capacitor-side bus bar and the board. According to this, when the bus bar on the substrate side is manufactured, the signal terminal can be formed at the same time, which is advantageous in reducing the manufacturing cost and the number of parts. Further, the bus bar on the substrate side may be provided as an insert component in a resin case accommodating the substrate. In this case, since the resin portion and the capacitor terminal are integrally inseparable, the resin portion is inevitably present on the root side of the capacitor terminal at the time of soldering. Therefore, the action and effect of providing the slit can be surely and effectively exhibited. Further, the bus bar on the substrate side may be configured as a punched product of a metal plate. According to this, it is possible to reduce the cost for manufacturing the terminal for the capacitor. In the above aspect, a hole is formed as the slit 7b through the signal terminal (capacitor terminal) in the thickness direction (Z direction), but as long as the flow to the wall portion 5c side of the solder is blocked, the through hole is formed. The hole is not limited to the hole to be formed, and may be a groove-shaped hole (recess) extended along the width direction (Y direction).

1 Capacitor module 2 Capacitor 3 Discharge resistance board (board)
4A, 4B Capacitor side bus bar 5c Wall part (resin part)
6A, 6B Substrate side bus bar 7 Signal terminal (capacitor terminal)
7a Joint hole 7b Slit

Claims (1)

The substrate and the capacitor are connected via a bus bar and are provided so as to protrude from the resin portion on the substrate side separated by sandwiching the resin portion, and the bus bar on the capacitor side is soldered to the substrate. A capacitor terminal for connecting the capacitor, which is located between the joint hole which is the target portion of the solder joint and the joint hole and the resin portion, and is orthogonal to the protruding direction from the resin portion. Capacitor terminals with slits extended along the width direction.

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