JPH0963894A - Electric double layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electric double layer capacitor in which an insulating board can be fixed to the electrode surface facing a printed board by holding the insulating board on one electrode surface side through a lead terminal and an engaging/holding means and bending the circumferential fringe of insulating board toward the center of a capacitor body at the intermediate part of each lead terminal. SOLUTION: An insulation board 11 is made of a heat resistant electric insulation material and has outer diameter substantially equal to or smaller than that of a capacitor body 10. The insulation board 11 is provided, on one side thereof, with an engaging/holding means 30 for lead terminals 13. The engaging/holding means 30 is provided with two pairs of pawls 31, 31 being engaged resiliently with the opposite side edges of the lead terminal 13 floating from the electrode surface. Each lead terminal 12, 13 is bent, at the intermediate part thereof toward the center of the capacitor body 10 so that the insulation board 11 is held from the opposite sides thus shortening the interval D of the lead terminals 12, 13 as compared with the conventional case.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric double layer capacitor, and more specifically, it is equipped with a coin-type capacitor cell and is mounted in a horizontal position so that one electrode surface thereof faces a printed circuit board. It relates to an electric double layer capacitor.

[0002]

2. Description of the Related Art An electric double layer capacitor has a coin-shaped capacitor cell as a minimum unit and is used in a state in which a plurality of stacked capacitor cells are stacked according to the application, but since it is not provided with a terminal member itself. For example, when mounting on a printed circuit board, lead terminals are attached to the respective electrode surfaces.

FIG. 6 shows a capacitor body 1 as a conventional example. That is, the capacitor body 1 is formed by stacking two capacitor cells 2 and 3. According to this, a cup-shaped coupling member 4 is attached to one of the capacitor cells 2 on the cathode surface 2a side by welding. The anode surface 3b side of the other capacitor cell 3 is fitted and held and welded to the same coupling member 4.

The capacitor body 1 is covered with a sleeve 5 made of a heat-shrinkable and electrically insulating resin, and lead terminals 6 and 7 are provided on the anode surface 2b and the cathode surface 3a located at both ends of the laminated body. Are attached respectively. In addition,
Since the cases of the capacitor cells 2 and 3, the coupling member 4, and the lead terminals 6 and 7 are each made of a stainless material, they are attached by, for example, laser welding.

As a mounting form of the capacitor body 1 on a printed circuit board (not shown), a so-called vertical type in which the electrode surfaces 2b and 3a are orthogonal to the printed circuit board surface, and one of the electrode surfaces 2b and 3a is the printed circuit board surface. There is a so-called horizontal type in which they are opposed to each other in parallel, and they are appropriately selected depending on the design. However, when mounting in the horizontal state, as shown in FIG. , 7 are bent in the same direction so that their free ends (insertion legs) are substantially perpendicular to the electrode surfaces 2b, 3a of the same capacitor body 1.

That is, in this example, the lead terminal 7 attached to the cathode surface 3a on the side facing the printed circuit board is bent at a substantially right angle directly from its attachment base and attached to the other anode surface 2b. Lead terminal 6
Is bent substantially at right angles from the periphery of the capacitor body 1 along the side surface of the sleeve 5 so as to be parallel to the lead terminals 7 (see, for example, Japanese Utility Model Laid-Open No. 3730/1993).
The lead terminals 6 and 7 are made of stainless steel strip,
The welded parts on the electrode surface are recesses 6a, 7a which are recessed one step lower than the other parts.

[0007]

However, in the horizontal type, when the lead terminals 6 and 7 are attached to the capacitor body 1 with the intention of enhancing the stability when mounted on a printed circuit board, Since the mounting directions are oriented so that their free end sides are opposite to each other and the distance D between the lead terminals 6 and 7 is wide, it occupies a large space on the printed circuit board. It will restrict the wiring of parts. Further, the electrode surface on the side facing the printed circuit board, in this example, the cathode surface 3a, is exposed to heat during soldering, which may adversely affect the characteristics of the capacitor.

An electric double layer capacitor having a capacitor body similar to that described above, in which the free end side of each lead terminal is bent outward and mounted on the surface of a printed circuit board, Actual Kaihei 5-2802
As can be seen in Japanese Patent Publication No. 3, the seat plate can be held by the respective lead terminals on the electrode surface side facing the printed circuit board. However, this inevitably requires a seat plate that is larger than the capacitor body, which occupies a large space on the printed circuit board and is not preferable when high-density mounting is required.

Further, since the free end side of each lead terminal is bent outward to form a surface mount type, the seat plate can be held by utilizing the lead terminal, and the lead terminal is printed as described above. The technique of this prior art cannot be directly applied to a so-called discrete type electric double layer capacitor which is inserted into a through hole of a substrate.

However, Japanese Utility Model Laid-Open No. 5-28023 discloses that in a discrete type electric double layer capacitor,
It has been proposed that a seat plate be interposed between the capacitor body and the printed circuit board to provide heat resistance. However, this electric double layer capacitor has a structure in which a plurality of coin-shaped capacitor cells are housed in a cylindrical metal case with a bottom, an electrode plate is attached to the sealing part, and a pair of lead terminals is pulled out from the electrode plate. And therefore a smaller seat plate than the capacitor body can be used,
It cannot be denied that the number of parts is large and the cost is high.

The present invention has been made to solve such a conventional problem, and an object thereof is to include at least one coin-shaped capacitor cell, and a lead terminal is provided on each electrode surface of the capacitor cell. Each of the lead terminals has a capacitor body formed by bending the free end side of each lead terminal in the same direction substantially perpendicular to the electrode surface, and is mounted so that one electrode surface of the capacitor body faces the printed circuit board. In the electric double layer capacitor, it is possible to reduce the distance between the lead terminals without impairing the stability when mounted on the printed circuit board, and to face the printed circuit board without using a special holder as a separate component. Good heat resistance because an insulating plate with the same diameter as or smaller than the capacitor body can be attached to the side electrode surface To provide an electric double layer capacitor.

[0012]

To achieve the above object, the invention of claim 1 includes at least one coin-shaped capacitor cell, and a lead terminal is attached to each electrode surface of the capacitor cell. An electric double layer capacitor provided with a capacitor body formed by bending the free end side of each lead terminal in the same direction which is substantially perpendicular to the electrode surface, and one electrode surface of which faces the printed circuit board. In an insulating plate made of a heat-resistant electric insulating material having the same diameter as or smaller than that of the capacitor body and having engagement holding means for the lead terminal, the insulating plate being the one electrode. Is held on the surface side through the lead terminals and the engaging and holding means, and the middle portion of each lead terminal is the peripheral edge of the insulating plate. It is characterized by being bent toward the center of the capacitor body as pressing.

According to this, the insulating plate can be attached to the electrode surface facing the printed circuit board without using a special holder or the like as a separate component. Also, by bending the middle portion of each lead terminal toward the center of the capacitor body so as to press the peripheral edge of the insulating plate, the distance between the lead terminals can be narrowed, and accordingly, on the printed circuit board. The degree of freedom in drawing the wiring pattern is relaxed, and the wiring density can be increased in some cases.

According to a second aspect of the present invention, the lead terminal is formed of a strip plate, and the engagement holding means is provided with at least a pair of engagement claws elastically engaging both side edges of the strip plate. According to this, the insulating plate can be easily attached to the electrode surface on the side facing the printed circuit board by a so-called one-touch operation.

The invention according to claim 3 is characterized in that the insertion legs for the printed circuit board, which are continuously provided at the bent portions of the lead terminals, are arranged symmetrically with respect to the center of the capacitor body. According to this, the interval between the lead terminals can be narrowed without impairing the stability when mounted on the printed circuit board.

Further, according to the invention of claim 4, the insulating plate is provided with a notch at a portion corresponding to the bent portion of each of the lead terminals. The diameter can be made larger than the space between the lead terminals, and the heat resistance of the electric double layer capacitor can be further improved.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, specific examples of the electric double layer capacitor of the present invention will be described in more detail with reference to FIGS. 1 to 5. In each of these drawings, the same reference numerals are used for the constituent elements that are the same as or can be regarded as the same as those of the conventional example described above with reference to FIG.

FIG. 1 shows a completed view of a capacitor body 10 of an electric double layer capacitor according to the present invention. According to this, the insulating plate 11 is arranged on the electrode surface side facing the printed circuit board (not shown), and the insulating plate 11 is held so as to be held by the lead terminals 12 and 13.

The insulating plate 11 is made of a heat-resistant electric insulating material (for example, glass epoxy resin) and has an outer diameter which is substantially the same as or smaller than that of the capacitor body 10, but which almost covers the electrode surface. It is supposed to be profitable.

Then, on one surface of the insulating plate 11,
As shown in FIG. 2, engagement holding means 30 for the lead terminal 13 is provided. In this case, the lead terminal 13 corresponds to the lead terminal 7 shown in the conventional example of FIG. 6, and similarly, only the welded portion with respect to the electrode surface is a recess 13a which is recessed one step lower than the other portions.

However, in FIG. 2, the lead terminal 13 is shown as being inverted, so that the concave portion 13a thereof is depicted as a convex portion, and therefore, the portion other than the concave portion 13a as the welding portion is the electrode. It is in a state of being floated from the surface with a predetermined gap.

On the premise of this, the engagement holding means 30 in this embodiment is capable of elastically engaging with both side edges of the lead terminal 13 which is in a state of being floated from the electrode surface thereof. It has mating jaws 31, 31. In this example, the engagement holding means 30 has two pairs of engagement claws 31, 31, but the minimum essential unit may be a pair.

Further, in this embodiment, the insulating plate 11 is formed in a disk shape, and the notches 11a for inserting the lead terminals 12 and 13 into the peripheral portions corresponding to the lead terminals 12 and 13, respectively. Although 11b is provided, the insulating plate 11 may have another shape, that is, a polygonal shape such as a triangle, a quadrangle, or a hexagon. , Insulating plate 11
May have any thickness.

The middle portion of each lead terminal 12 and 13 is bent toward the center of the capacitor body 10 so as to hold the insulating plate 11 from both sides thereof, whereby the distance D between the lead terminals 12 and 13 is reduced to the conventional value. It is narrower than the example. Even if the distance D is narrowed in this way, by mounting the free ends (insertion legs with respect to the printed circuit board) of the lead terminals 12 and 13 symmetrically with respect to the center of the capacitor body 10, the printed circuit board mounting is performed. The stability of time is not impaired.

Next, an example of a method of attaching the insulating plate 11 to the capacitor body 10 will be described with reference to FIGS. In these figures, the capacitor body 10 is drawn in an opposite manner to that of FIG.

As shown in FIG. 3, the capacitor body 10 is composed of two capacitor cells 2 and 3 stacked with a coupling member 4 interposed therebetween, and is similar to the conventional example.
One lead terminal 12 is attached to the anode surface 2b and the other lead terminal 13 is attached to the cathode surface 3a side. In this case, the lead terminals 12 and 13 are formed in advance as follows. .

That is, the lead terminal 12 has an attachment base 121 welded to the anode surface 2b, and an intermediate portion 122 bent from the periphery of the capacitor body 10 along the sleeve 5 at substantially right angles to the attachment base 121. On the free end side of the intermediate portion 122, there is provided an inserting leg 123 for the printed circuit board, which is bent outward at a substantially right angle.

The intermediate portion 122 has a length corresponding to the axial length of the capacitor body 10 and extends around the cathode surface 3a side to insulate the insulating plate 11.
The length of the insertion leg 123 is such that the insertion leg 123 is substantially perpendicular to the printed circuit board (not shown) when the intermediate portion 122 is bent toward the cathode surface 3a side. It is bent almost at a right angle to.

The other lead terminal 13 has a mounting base 131 welded to the cathode surface 3a, an intermediate portion 132 raised from the mounting base 131 at a substantially right angle, and a free end side of the intermediate portion 132 outwardly. The insert leg 133 for the printed circuit board bent at a substantially right angle is provided.

In this case, the intermediate portion 132 has a length capable of pressing the peripheral edge portion of the insulating plate 11 when the intermediate portion 132 is bent approximately 90 degrees toward the center of the capacitor body 10. When bent in this manner, it is previously bent substantially at right angles to the intermediate portion 132 so as to be substantially perpendicular to a printed circuit board (not shown).

When the intermediate portions 122 and 132 are bent as described above to press the insulating plate 11,
The insertion legs 123 and 133 are the main body 10 of the capacitor.
The length is preferably such that it is arranged symmetrically with respect to the center of. Further, the lead terminals 12 and 13 are attached to the capacitor body 10 such that the insertion legs 123 and 133 thereof face in opposite directions.

When the insulating plate 11 is provided on the electrode surface facing the printed circuit board, in this example, on the cathode surface 3a side (actually, on the mounting base 131 of the lead terminal 13), the engaging claw 31 is first attached to the lead terminal. The insulating plate 11 is pressed against the lead terminal 13 side in a state of being opposed to both side edges of the lead terminal 13, and the engaging claws 31 are engaged with the both side edges of the lead terminal 13.

After holding the insulating plate 11 on the lead terminals 13 in this manner, as shown by the arrows in FIG. 4, the intermediate portions 122 and 132 of the lead terminals 12 and 13 are formed.
Is bent approximately 90 degrees toward the center of the capacitor body 10.

As a result, as shown in FIG.
The peripheral edge of the insulating plate 11 is pressed by the intermediate portions 122 and 132 and held on the cathode surface 3a, and the insertion legs 123 and 133 are oriented in the vertical direction. During this bending work, the insulating plate 11 is temporarily held by the above-mentioned engaging claws 31 so that there is no risk of falling off, and therefore the bending work can be performed easily.

[0035]

As described above, according to the present invention,
In a horizontal mounting type electric double layer capacitor, it is possible to attach an insulating plate made of a heat-resistant electric insulating material with a size equal to or smaller than the capacitor body on the electrode surface side facing the printed circuit board. Provided is an electric double layer capacitor having good heat resistance against heat during soldering.

Even if the insulating plate is held on the electrode surface, the insulating plate can be temporarily attached to the lead terminals by a so-called one-touch operation, and then the intermediate portion of each lead terminal is attached to the capacitor body. By bending the insulating plate toward the center and holding the peripheral edge of the insulating plate at the bent portion, the insulating plate can be reliably held without the need for new additional parts.

Further, as the intermediate portion of each lead terminal is bent toward the center of the capacitor body, the distance between the respective insertion legs with respect to the printed circuit board is narrowed, and the wiring pattern area on the printed circuit board is correspondingly reduced. Can be made large, the degree of freedom in drawing a wiring pattern can be relaxed, and the wiring density can be increased.

Even if the middle portion of each lead terminal is bent toward the center of the capacitor body, the insertion leg for the printed circuit board connected to the bent portion is symmetrical with respect to the center of the capacitor body. By arranging them, not only the spacing between the lead terminals can be narrowed without impairing the stability at the time of mounting on the printed circuit board, but also the spacing between the insertion legs can be adjusted according to the needs of the user side. It can be changed arbitrarily.

In addition, by providing the insulating plate with the notches corresponding to the respective lead terminals, the outer diameter of the insulating plate can be made larger than the space between the bent lead terminals, so that the electric double layer capacitor The heat resistance can be further improved.

[Brief description of drawings]

FIG. 1 is an external perspective view of a capacitor body that substantially constitutes the electric double layer capacitor of the present invention.

FIG. 2 is a perspective view showing a relationship between an engagement holding means provided on an insulating plate and a lead terminal.

FIG. 3 is a side view including a partial cross section showing a state in which an insulating plate is attached to a lead terminal of a capacitor body.

FIG. 4 is a side view including a part of a cross section for explaining a state in which an insulating plate is temporarily fixed to a capacitor body and an intermediate portion of each lead terminal is bent.

FIG. 5 is a side view including a cross section in a part corresponding to FIG. 1 showing a state in which an intermediate portion of each lead terminal is bent and an insulating plate is held.

FIG. 6 is a side view showing a partial cross-section of a conventional horizontal mounting type electric double layer capacitor.

[Explanation of symbols]

 2,3 Coin-shaped capacitor cell 4 Coupling member 5 Sleeve 10 Capacitor body 11 Insulating plate 12,13 Lead terminal 121,131 Attachment base 122,132 Intermediate part 123,133 Insertion leg 30 Engagement retainer 31 Engagement claw

Claims (4)

[Claims] 1. At least one coin-shaped capacitor cell is provided, and a lead terminal is attached to each electrode surface of the capacitor cell, and the free end side of each lead terminal is substantially the same as the electrode surface. An electric double-layer capacitor that is mounted so that one electrode surface thereof faces the printed circuit board, and has the same diameter as or smaller than that of the capacitor body. And an insulating plate made of a heat-resistant electrically insulating material having engagement holding means for the lead terminal, the insulating plate being held on the one electrode surface side via the lead terminal and the engagement holding means. At the same time, the middle portion of each lead terminal is oriented toward the center of the capacitor body so as to press the peripheral edge of the insulating plate. An electric double layer capacitor characterized by being bent and folded. 2. The lead terminal is formed of a strip plate, and the engagement holding means is provided with at least a pair of engagement claws elastically engaging both side edges of the strip plate. 1. The electric double layer capacitor described in 1. 3. The insertion leg for a printed circuit board, which is connected to the bent portion of each of the lead terminals, is arranged symmetrically with respect to the center of the capacitor body. Electric double layer capacitor. 4. The electric double layer capacitor according to claim 1, wherein the insulating plate is provided with a notch at a portion corresponding to a bent portion of each of the lead terminals.