JP2021190535A - Chip type capacitor - Google Patents

Abstract

To improve the vibration resistance of a chip type capacitor.SOLUTION: A chip type capacitor includes a bottomed cylindrical storage container that houses a capacitor element inside, a sealing body having an insertion hole for inserting a lead drawn from the capacitor element while sealing the open end of the storage container, a seat plate having a flat plate-shaped seat plate main body facing the open end of the storage container and a collar portion protruding from the corner portion of the seat plate main body and holding an outer surface of the storage container, and a covering material that covers at least a part of the storage container attached to the seat plate and at least a part of the collar portion.SELECTED DRAWING: Figure 1

Description

The present invention relates to a chip type capacitor that is required to have vibration resistance.

Conventionally, in a chip type electrolytic capacitor, a seat plate made of resin or the like having an insertion hole through which a lead wire can be inserted is attached to the capacitor body on the sealing side of the capacitor body, and the lead wire is folded along the seat plate. A shape that can be bent and surface-mounted on a substrate is used.

In recent years, vibration resistance has been particularly required for chip-type electrolytic capacitors. As a measure against vibration, collars (walls) are provided at the four corners of the seat plate, and the collar provides a metal case for the capacitor body. A structure that holds the peripheral surface of the above is used (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2017-20409

In the conventional chip-type electrolytic capacitor that supports vibration resistance, measures such as providing a collar on the seat plate are taken, but when the capacitor body presses one collar part due to vibration, the other collar part and the capacitor body are taken. Since a gap is created between the capacitor and the capacitor, further improvement in vibration resistance is required for applications with large vibration mounted on vehicles and the like.

The present invention has been made in consideration of the above points, and an object of the present invention is to improve the vibration resistance of a chip type capacitor.

The chip-type capacitor of the present invention has a bottomed cylindrical storage container containing a capacitor element inside, and a sealing body having an insertion hole for inserting a lead drawn from the capacitor element while sealing the open end of the storage container. A seat plate having a flat plate-shaped seat plate main body facing the open end of the storage container and a collar portion protruding from a corner of the seat plate main body and holding an outer surface of the storage container, and storage attached to the seat plate. It is characterized by comprising a covering material that covers at least a part of the container and at least a part of the collar portion.

According to this configuration, the storage container and the seat plate can be integrated, and the storage container and the seat plate can be suppressed from vibrating separately.

Further, the chip type capacitor of the present invention is characterized in that, in the above configuration, the coating material is a heat-shrinkable resin.

According to this configuration, by using the heat-shrinkable resin as the covering material, the storage container and the seat plate can be brought into close contact with each other and integrated in a simple process.

Further, the chip type capacitor of the present invention is characterized in that, in the above configuration, a protrusion is provided on the surface of the collar portion covered with the covering material.

According to this configuration, by covering with the covering material including the protrusions, it is possible to obtain the effect that the covering material is hard to come off.

According to the chip type capacitor of the present invention, vibration resistance can be improved.

It is a perspective view which shows the chip type electrolytic capacitor which concerns on embodiment of this invention. It is a top view which shows the chip type electrolytic capacitor which concerns on embodiment of this invention. It is sectional drawing which shows the AA line in FIG. 2 in the cross section. It is sectional drawing which shows the BB line in FIG. 2 in the cross section. It is a perspective view which shows the state before coating of the chip type electrolytic capacitor which concerns on embodiment of this invention. It is a side view which shows the capacitor main body which concerns on embodiment of this invention. It is a side view which shows the covering area of the chip type electrolytic capacitor which concerns on embodiment of this invention. It is a perspective view which shows the chip type electrolytic capacitor which concerns on other embodiment. It is sectional drawing which shows the substrate which mounted the chip type electrolytic capacitor which concerns on other embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 is a perspective view showing a chip-type electrolytic capacitor 100 provided with a covering material 30, FIG. 2 is a plan view thereof, FIG. 3 is a cross-sectional view showing the line AA in a cross section, and FIG. 4 is a cross-sectional view thereof. It is a cross-sectional view which shows the BB line in the cross section, FIG. 5 is a perspective view which shows the capacitor main body 10 and the seat plate 20 before covering with a covering material 30, and FIG. 6 shows the appearance of the capacitor main body 10. It is a side view.

As shown in FIGS. 1 to 6, the chip type electrolytic capacitor 100 in the present embodiment includes a capacitor main body 10, a seat plate 20, and a covering material 30, and has a pair of leads 3 of the capacitor main body 10 as a substrate (not). It is mounted on the surface of the substrate by being electrically connected to (shown). As shown in FIG. 3, the capacitor main body 10 has a capacitor element 1, a bottomed cylindrical storage container 2 for storing the capacitor element 1 impregnated with an electrolytic solution, and a pair of leads connected to the capacitor element 1. 3 and a sealing body 4 in which an opening end of the storage container 2 is sealed and an insertion hole 4a through which a pair of leads 3 are inserted are formed.

The capacitor element 1 is configured by connecting a pair of leads 3 for taking out an electrode to an anode foil and a cathode foil having an oxide film formed on an aluminum foil, and winding the capacitor element 1 via a separator.

The storage container 2 is a bottomed cylindrical case made of aluminum as a material. A pressure valve 2d is provided on the bottom surface 2c of the storage container 2. Further, as shown in FIG. 6, the outer peripheral surface 2a of the storage container 2 is formed with a recess 2b extending in an annular shape along the circumferential direction thereof. The recess 2b is formed by inserting the sealing body 4 into the storage container 2 and then drawing the outer peripheral surface 2a of the storage container 2. The sealing body 4 is made of an elastic rubber such as isobutylene-isoprene rubber (IIR) or ethylene propylene terpolymer (EPT) as a material.

The seat plate 20 is made of synthetic resin and has insulating properties. The seat plate 20 is attached to the condenser main body 10 in a state of being in contact with the end portion (lower end portion of FIGS. 3 and 4) of the condenser main body 10 on the sealing body 4 side. That is, the seat plate 20 is attached to the capacitor main body 10 in a state of facing the sealing body 4. Further, the seat plate 20 has a flat plate-shaped seat plate main body 21. The seat plate main body 21 has a substantially square planar shape, but the planar shape is not particularly limited. The seat plate main body 21 has a hole 20a through which a pair of leads 3 derived from the capacitor element 1 is inserted, and a groove 20b for storing the pair of leads 3 inserted through the hole 20a by bending them at right angles. ing.

The mounting surface 21a on which the capacitor body 10 is mounted facing the sealing body 4 of the seat plate main body 21 is provided with a protruding collar portion 22 at each corner (four places) of the mounting surface 21a, and this collar is provided. The inner surface 22a of the portion 22 holds the outer peripheral surface 2a of the storage container 2. That is, the inner surface 22a of the collar portion 22 has a curved surface shape that matches the shape of the outer peripheral surface 2a of the storage container 2, and the inner surface 22a can hold the outer peripheral surface 2a of the storage container 2. ..

Since a slight gap is formed between the outer peripheral surface 2a of the storage container 2 and the inner surface 22a of the collar portion 22, the work can be smoothly performed when the storage container 2 is mounted on the seat plate main body 21. You can do it.

Further, in a state where the storage container 2 (capacitor main body 10) is mounted on the seat plate 20, at least a part of the outer peripheral surface 2a and a part of the collar portion 22 of the storage container 2 are covered with a covering material 30 made of a heat-shrinkable resin. Has been done. The coating material 30 is made of a highly heat-shrinkable resin material (for example, saturated polyester resin, polyvinyl chloride, fluororesin, etc.), and after mounting the condenser element 10 on the seat plate 20, the resin material in the form of a sheet is formed. The resin is wound around the outer peripheral surface 2a while including the collar portion 22 and heated at 85 ° C. for about 10 minutes so as to cover the storage container 2 of the condenser main body 10 and the collar portion 22 of the seat plate 20. In this way, the covering material 30 is in close contact with the outer peripheral surface 2a and the collar portion 22 of the storage container 2, so that the storage container 2 and the collar portion 22 are in close contact with each other by the resin material 30 and are integrated with each other. Even when vibration is applied to the chip-type electrolytic capacitor 100, it is possible to suppress the storage container 2 and the collar portion 22 (seat plate 20) from vibrating separately.

In the case of the present embodiment, the range covered by the covering material 30 is a range including a part of the bottom surface 2c of the storage container 2 (a region avoiding the pressure valve 2d), the outer peripheral surface 2a, and the collar portion 22. There is.

Here, as shown in FIG. 7, the height H1 in which the covering material 30 covers the storage container 2 covers from the tip end (upper end) of the collar portion 22 of the seat plate 20 to the vicinity of the mounting surface 21a of the seat plate main body 21. It is the height to get. As a result, a part of the seat plate 20 (collar portion 22) and the storage container 2 can be integrally brought into close contact with each other by the resin material 30. In this way, the seat plate 20 having the collar portion 22 is covered with the resin material 30 so as to include at least a part thereof (collar portion 22) and the storage container 2, so that the collar portion is particularly covered. When the storage container 2 sandwiched between the 22 and the collar portion 22 are brought into close contact with each other by the covering material 30 and integrated, it is possible to suppress the storage container 2 from vibrating between the collar portions 22. As a result, it is possible to prevent the capacitor body 10 from falling off from the seat plate 20.

Further, by covering the capacitor body 10 with the covering material 30 including a part of the collar part 22 of the seat plate 20, the height of the collar part 22 provided for the purpose of preventing the capacitor body 10 from falling off is lowered. Even if it is suppressed, the collar portion 22 and the capacitor body 10 can be sufficiently brought into close contact with each other by the covering material 30, and the capacitor body 10 can be sufficiently suppressed from falling off.

Further, the covering material 30 can cover the region including the concave portion 2b of the storage container 2 so that the portion covered by the covering material 30 includes the uneven portion such as the concave portion 2b, and the surface without unevenness. The adhesion of the covering material 30 can be further improved as compared with the case of covering only.

Next, the manufacturing process of the chip type electrolytic capacitor 100 in this embodiment will be described.
First, the electrode pull-out reed 3 is connected to each of the anode foil and the cathode foil while being wound around a cylindrical capacitor element via an electrolytic paper between the two electrode foils. Stop the end of winding with element stopper tape (crimping, winding process). Next, the capacitor element is impregnated with the driving electrolyte (impregnation step). Next, the lead of the capacitor element impregnated with the electrolytic solution is inserted through the insertion hole 4a provided in the sealing body 4, then placed in the storage container 2, and the opening of the storage container 2 is curled and the outer peripheral surface 2a is formed. Is drawn and sealed (assembly process). Next, a DC voltage is applied to the electrolytic capacitor (product) at a high temperature to repair the oxide film damaged by cutting or winding the foil (aging process). Next, the pair of leads 3 is flattened by a press to insert a hole 20a through which the leads 3 formed in the seat plate main body 21 are inserted, and then bent at a right angle so as to separate from each other into the seat plate main body 21. It is arranged in the formed groove 20b. In this way, the seat plate 20 is attached to the capacitor main body 10 in a state of facing the sealing body 4 (seat plate attaching step). The heat-shrinkable resin is wound around the outer peripheral surface 2a and the collar portion 22 of the storage container 2 and heated with respect to the chip-type electrolytic capacitor 100 assembled by these steps, so that the covering material 30 is brought into close contact with the chip-type electrolytic capacitor 100.
Thereby, the chip type electrolytic capacitor 100 provided with the covering material 30 can be manufactured.

In this way, the coating material 30 is provided by winding a sheet-shaped heat-shrinkable resin around the assembled chip-type electrolytic capacitor 100, so that the coating material 30 is provided without significantly changing the existing manufacturing process. The material 30 can be provided.

Further, by using the heat-shrinkable resin as the covering material 30, the capacitor main body 10 (storage container 2) and the seat plate 20 (collar portion 22) have a simple structure in which a sheet-shaped heat-shrinkable resin is wound and heated. Can be brought into close contact with.

Further, the completed chip-type electrolytic capacitor 100 is mounted on the substrate, and the chip-type electrolytic capacitor 100 is mounted on the substrate by performing a reflow soldering process. In this case, in the chip type electrolytic capacitor 100 of the present embodiment, the adhesion between the capacitor main body 10 and the seat plate 20 is improved by providing the covering material 30 on the outer peripheral surface 2a of the storage container 2. .. Therefore, as a configuration for improving the adhesion, for example, there is an advantage as shown below as compared with a configuration in which a resin is filled between the capacitor main body 10 and the mounting surface 21a of the seat plate 20 to bring them into close contact with each other. That is, according to the present embodiment, since the mounting surface 21a of the seat plate 20 and the capacitor main body 10 are not fixed, the internal pressure of the capacitor main body 10 when the chip type electrolytic capacitor is reflow mounted on the substrate. Even if the capacitor body 10 is deformed due to the increase in the pressure, the seat plate 20 does not warp accordingly, and the capacitor body 20 can be reliably mounted on the substrate.

In the above embodiment, as shown in FIG. 7, the height H1 (the height covering a part of the collar portion 22 of the seat plate 20) is within the range from the bottom plate 2b of the storage container 2 of the capacitor main body 10. The case where the covering material 30 is formed has been described, but the present invention is not limited to this, and various heights can be applied as long as the forming height of the covering material 30 is a height including the collar portion 22. Further, the seat plate 20 and the storage container 2 may all be covered. However, when the pressure valve 2d is provided on the bottom plate 2b of the storage container 2, it is necessary to avoid the area and cover the pressure valve 2d.

Further, for example, as shown in FIG. 8, the convex portion 22c may be provided in the region covered by the covering material 30 on the outer surface 22b of the collar portion 22. By doing so, the covering material 30 including the convex portion 22c can have the effect that the covering material 30 is hard to come off because the convex portion 22c is provided. In addition, instead of the convex portion 22c, a concave portion may be formed, and in short, by providing unevenness on the surface covered by the covering material 30, it is possible to prevent the covering material 30 from easily coming off.

Further, in the above-described embodiment, the case where the storage container 2 and the seat plate 20 of the capacitor main body 10 are brought into close contact with each other by the covering material 30 is described, but the present invention is not limited to this, and for example, as shown in FIG. 9, the substrate 50. The seat plate 20 and the storage container 2 may all be covered with the covering material 30. By doing so, the substrate, the seat plate 20, and the storage container 2 can be integrated together, and the vibration resistance of the capacitor main body 10 to the substrate and the seat plate 20 can be further improved.

Further, in the above-described embodiment, as a method of forming the covering material 30, a sheet-shaped heat-shrinkable resin is wound, but the present invention is not limited to this, and for example, the coated portion is covered with a ring-shaped heat-shrinkable resin. It may be covered and heated so as to cover it, or it may be attached and heated so as to cover the covering target portion with a clay-like heat-shrinkable resin.

In the above-described embodiment, the case where the present invention is applied to a chip-type aluminum electrolytic capacitor has been described, but the present invention is not limited to this, and any chip-type capacitor can be applied to various other capacitors. can.

2 Storage container 2a Outer peripheral surface 3 Lead 4 Sealing body 10 Capacitor body 20 Seat plate 21 Seat plate body 22 Collar 30 Covering material 100 Chip type electrolytic capacitor

Claims (3)

A bottomed cylindrical storage container that houses a capacitor element inside,
A sealing body having an insertion hole for inserting a lead drawn from the capacitor element while sealing the open end of the storage container.
A seat plate having a flat plate-shaped seat plate main body facing the open end of the storage container and a collar portion protruding from a corner portion of the seat plate main body and holding an outer surface of the storage container.
A chip type capacitor comprising a covering material that covers at least a part of the storage container attached to the seat plate and at least a part of the collar portion. The chip type capacitor according to claim 1, wherein the covering material is a heat-shrinkable resin. The chip type capacitor according to claim 1 or 2, wherein a protrusion is provided on the surface of the collar portion covered with the covering material.

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