JPH0878290A - Manufacture of solid electrolytic chip capacitor - Google Patents

Abstract

PURPOSE: To obtain a solid electrolytic chip capacitor in which the size and cost can be reduced. CONSTITUTION: The solid electrolytic chip capacitor 10 comprises a capacitor element 16 produced by forming a solid electrolytic layer 14 and a cathode layer 15 on a sintered pellet 13 planted with an anode rod 12 and then molding the entirety with a resin 17. The molding resin 17 is then partially removed to expose the surface 18 of the cathode layer 15 onto which a cathode terminal 19 is formed continuously to the peripheral surface of the molding resin 17. Subsequently, the anode rod 12 is bent toward the radial direction of the capacitor element 16 and a planar terminal 20 is provided at the forward end.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chip type solid electrolytic capacitor, and more particularly to a chip type solid electrolytic capacitor which can be downsized and can be manufactured at a reduced cost.

[0002]

2. Description of the Related Art In recent years, with the miniaturization of electronic equipment, a chip type solid electrolytic capacitor surface-mounted on a printed circuit board has a smaller planar shape in order to improve the volume efficiency on the printed circuit board. The height dimension is also required to be low. For example, in the chip-type solid electrolytic capacitor 30 shown in FIG. 3, a sintered pellet 30A in which an anode rod 31 is implanted has a capacitor element 34 in which a solid electrolyte layer 32 and a cathode layer 33 are formed. An anode terminal 35 welded to 31 and a cathode terminal 37 connected to the cathode layer 33 by using a conductive adhesive 36 or the like are bent along the exterior resin 38 of the capacitor element 34 and the circuit board 39 into a so-called crab-like shape. The above-mentioned objects are achieved by these.

However, in this chip type solid electrolytic capacitor 30, the anode terminal 3 which is a separate member (lead frame) is used.
5. Since the cathode terminal 37 is connected to the anode rod 31 and the cathode layer 33, respectively, and is routed around the exterior resin 38, there is a limit to downsizing, and the number of parts is increased and the manufacturing process is complicated. Was invited. Further, in general, when the anode terminal and the cathode terminal of the chip type solid electrolytic capacitor are long, an inductance component is easily generated, which is a problem in terms of characteristics.

On the other hand, the chip-type solid electrolytic capacitor 40 shown in FIG. 4 is based on Japanese Patent Publication No. 1-265727 proposed to solve such a problem. According to this, the exterior resin 43 is formed around the capacitor element 42 in which the solid electrolyte layer and the cathode layer are formed on the sintered pellet 41.
In order to provide the above, the exterior resin 43 is formed by leaving the cathode extraction portion 44 exposing the cathode layer and the anode extraction portion 46 from which the anode rod 45 projects. Then, a cathode part conductive layer 44A and an anode part conductive layer 46A are formed on the cathode extraction part 44 and the anode extraction part 46, respectively, and the electroless plating 4 is formed on each of these surfaces.
7 has been given. This chip type solid electrolytic capacitor 4
According to No. 0, when surface mounting on the circuit board 48, an anode terminal formed of a lead frame as a separate member,
Since the cathode terminal is not necessary, the problem of the chip type solid electrolytic capacitor 30 described above can be solved.

[0005]

However, in this chip type solid electrolytic capacitor 40, the cathode part conductive layer 44 is used.
A. Since the anode part conductive layer 46A wraps around to the peripheral surface of the capacitor element 42, the diameter of the part tends to increase. Therefore, the chip type solid electrolytic capacitor 40 is
There is no choice but to increase the height dimension on the circuit board 48, and there is a problem that volume efficiency is poor. The present invention has been made to solve the above conventional problems, and an object thereof is to provide a chip-type solid electrolytic capacitor that can achieve miniaturization and reduce manufacturing cost.

[0006]

In order to achieve the above-mentioned object, the invention described in claim 1 of the present invention provides a solid electrolyte layer on a sintered pellet made of valve metal powder in which an anode rod is implanted. A chip-type solid electrolytic capacitor having a capacitor element formed with a cathode layer made of carbon and a silver layer, and an exterior resin molded on the capacitor element, wherein the cathode layer is partially lacking the exterior resin. A cathode terminal made of solder plating having a surface continuous with the peripheral surface of the exterior resin is formed on the exposed surface, and the anode rod is bent in the radial direction of the capacitor element and has a plate-like shape at its tip. It is characterized in that the anode terminal is provided. In this case, the anode terminal may be formed into a desired shape by thinly crushing the tip of the anode rod, and the contact surface to the circuit board should be arranged in the same plane as the peripheral surface of the exterior resin and the cathode terminal. Good.

The invention according to claim 2 of the present invention is characterized in that the anode terminal extends in a direction along a tangential direction of the capacitor element.
In the invention according to claim 3 of the present invention, the anode rod has a flat portion formed at the tip of the anode rod, and an angle-shaped anode terminal leg connected to the flat portion. It is characterized by that. The flat portion may be formed so that the anode terminal leg can be connected to the anode rod,
Spot welding, laser welding, etc. may be used for connection with the anode terminal leg.

[0008]

In the invention described in claim 1 of the present invention, since the cathode terminal has the surface continuous with the peripheral surface of the exterior resin, the diameter of the portion does not increase. Therefore, compared with the conventional chip type solid electrolytic capacitor, the height dimension can be reduced and the volume efficiency can be improved. At this time, if the contact surface of the anode terminal to the circuit board is arranged in the same plane as the peripheral surface of the exterior resin and the cathode terminal, the height of the chip type solid electrolytic capacitor can be kept low and the cathode The terminal and the anode terminal come into contact with the circuit board at the same time.

According to the second aspect of the present invention, the anode terminal extends in the direction along the tangential direction of the capacitor element, that is, in the direction intersecting the axial direction of the capacitor element. Even when the chip type solid electrolytic capacitor having the cylindrical capacitor element is mounted on the circuit board, reliable mounting stability can be obtained.

In the invention according to claim 3 of the present invention, a flat portion is formed at the tip of the anode rod, and an angle-shaped anode terminal leg is connected to this tip. That is, the tip of the anode rod has only to have a minute flatness to which the anode terminal leg can be connected, which facilitates the processing. Moreover, the chip-type solid electrolytic capacitor has different shapes, depending on various situations where it is surface-mounted on the circuit board.
It is possible to easily expand the variation of the surface mounting form by selectively using the anode terminal leg having the size or by appropriately selecting the connection form between the anode rod and the anode terminal leg, and thereby the above object is achieved. .

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show one embodiment according to the present invention. The chip-type solid electrolytic capacitor 10 according to the present embodiment is surface-mounted on the circuit board 11.
It has a capacitor element 16 in which a solid electrolyte layer 14 and a cathode layer 15 made of carbon and silver layers are formed on a sintered pellet 13 made of valve action metal powder such as tantalum or the like in which an anode rod 12 is implanted.

The capacitor element 16 has an exterior resin 17 molded around it, and the cathode layer 15 is exposed to the outside by exposing the exterior resin 17 partially by using an appropriate means. Are formed. The capacitor element 16 has a cathode terminal 19 formed by solder plating on the exposed surface 18. On the other hand, the anode rod 12 protruding from the exterior resin 17 is bent in the radial direction of the capacitor element 16 (downward in FIG. 1), and a plate-shaped anode terminal 20 is provided at the tip thereof.

The cathode terminal 19 is solder-plated on the cathode layer 15 of the exposed surface 18, and the peripheral surface thereof is the exterior resin 1.
It is formed so as to be flush with the peripheral surface of 7. On the other hand, as shown in FIG. 2, the anode terminal 20 includes a flat portion 12A formed at the tip of the anode rod 12 and an angle-shaped anode terminal leg 21 connected to the flat portion 12A. . The flat portion 12A is formed into a substantially battledore shape that can be connected to the anode terminal leg 21 by thinly crushing the tip of the anode rod 12. The anode terminal leg 21 is arranged such that its longitudinal direction is along the tangential direction of the capacitor element 16, and is connected to the flat portion 12A by appropriate means such as spot welding or laser welding. Such an anode terminal leg 21 is housed in a minute space between the anode rod 12 bent downward and the exterior resin 17, as shown in the figure. Returning to FIG. 1, the cathode terminal 1 as described above
9, the anode terminal 20, the circuit board 1 in the exterior resin 17
It has contact surfaces 22 and 23 arranged in the same plane including the side surface facing 1.

In manufacturing the chip type solid electrolytic capacitor 10 of this embodiment, a capacitor element 16 in which a solid electrolyte layer 14 and a cathode layer 15 are formed on a sintered pellet 13 in which an anode rod 12 is implanted is used as an exterior resin 17. Mold. Then, the exterior resin 17 at a predetermined position in the capacitor element 16 is removed by an appropriate means such as a mechanical method, a laser, or a chemical method to form an exposed surface 18 where the cathode layer 13 is exposed to the outside. The exposed surface 18 is
The same effect can be obtained by molding the capacitor element 16 by bringing a predetermined cathode layer 13 into contact with the inner wall of the cavity.

Next, on the cathode layer 15, the exposed surface 18
Then, the cathode terminal 19 made of solder plating is formed. Then, the flat portion 12A is formed at the tip of the anode rod 12 and is bent in the radial direction of the capacitor element 16 (downward in FIG. 1), and the anode terminal leg 21 is spot-welded to the anode rod 12 via the flat portion 12A. Then, the chip type solid electrolytic capacitor 10 is obtained by connecting by an appropriate means such as laser welding.

According to this embodiment as described above, since the contact surface 22 of the cathode terminal 19 is continuous with the peripheral surface of the exterior resin 17, the diameter of the portion does not increase, and the height dimension on the circuit board 11 is increased. Can be lowered to improve the volumetric efficiency of the chip-type solid electrolytic capacitor 10. Further, since the contact surface 23 of the anode terminal 20 is arranged in the same plane as the contact surface 22 of the cathode terminal 19, the cathode terminal 19 is maintained while keeping the height dimension of the chip type solid electrolytic capacitor 10 low. And the anode terminal 20 can simultaneously contact the circuit board 11.

Further, the anode terminal 20 is the capacitor element 1.
Since it extends in the direction along the tangential direction of 6,
Chip type solid electrolytic capacitor 1 on circuit board 11
When 0, stable mountability is obtained. Further, the anode terminal 20 is configured by connecting the anode terminal leg 21 to the flat portion 12A. For this reason, the flat portion 12A has the anode terminal leg 2
It suffices to form it to the extent that 0 can be connected, which facilitates its processing. Then, according to various situations of the circuit board 11 on which the chip-type solid electrolytic capacitor 10 is surface-mounted, anode terminal legs having different shapes and sizes are selectively used, or a connection form between the anode rod and the anode terminal legs. By appropriately selecting, the variation of the surface mounting form can be easily expanded.

The present invention is not limited to the above-mentioned embodiments, and for example, materials, shapes, dimensions, forms and numbers of anode rods, flat portions, exposed surfaces, cathode terminals, anode terminals, anode terminal legs, etc. The formation position and the like are arbitrary and are not limited as long as the present invention can be achieved.

[0019]

According to the invention described in claim 1 of the present invention, the diameter of the cathode terminal is not increased and the volume efficiency of the chip type solid electrolytic capacitor can be improved. Further, according to the invention described in claim 2 of the present invention, the placement stability of the chip-type solid electrolytic capacitor on the circuit board can be obtained regardless of the shape of the capacitor element. According to the invention described in claim 3 of the present invention, by selecting the form of the anode terminal, the variation of the surface mounting form of the chip type solid electrolytic capacitor on the circuit board can be expanded.

[Brief description of drawings]

FIG. 1 is a front view and a side view showing an embodiment of the present invention.

FIG. 2 is a partial perspective view showing an anode terminal in the embodiment.

FIG. 3 is a sectional view showing a conventional chip type solid electrolytic capacitor.

FIG. 4 is a sectional view showing a conventional chip type solid electrolytic capacitor.

[Explanation of symbols]

 10 Chip type solid electrolytic capacitor 12 Anode rod 12A Flat part which is the tip of the anode rod 13 Sintered pellet 14 Solid electrolyte layer 15 Cathode layer 16 Capacitor element 17 Exterior resin 18 Exposed surface 19 Cathode terminal 20 Anode terminal 21 Anode terminal leg

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kaname Kurihara 2-2-1 Tsujido Shinmachi, Fujisawa-shi, Kanagawa Elner Co., Ltd. (72) Inventor Hiroshi Mizutsuki 2-2-1 Tsujido Shinmachi, Fujisawa-shi, Kanagawa Elner Co., Ltd.

Claims (3)

[Claims] 1. A capacitor element having a solid electrolyte layer and a cathode layer composed of a carbon and a silver layer formed on a sintered pellet made of valve-acting metal powder in which an anode rod is implanted, and the capacitor element is provided. In a chip-type solid electrolytic capacitor in which an exterior resin is molded, a cathode terminal made of solder plating having a surface continuous with the peripheral surface of the exterior resin is formed on the exposed surface of the cathode layer that is partially lacking the exterior resin. The anode rod is bent in the radial direction of the capacitor element, and a plate-shaped anode terminal is provided at the tip of the capacitor element. 2. The chip type solid electrolytic capacitor according to claim 1, wherein the anode terminal extends in a direction along a tangential direction of the capacitor element. 3. The anode rod has a flat portion formed at a tip of the anode rod, and an angle-shaped anode terminal leg connected to the flat portion. The chip-type solid electrolytic capacitor according to claim 2.