JP2002299165A - Chip-type solid electrolytic capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate positioning of a capacitor element to a lead frame, in a chip-type solid electrolytic capacitor. SOLUTION: In this chip-type solid electrolytic capacitor 1, the capacitor element 2, from which an anode lead-out line 4 is led out and a sheath resin 3 for covering the capacitor element 2 are installed, and an anode terminal 5 and a cathode terminal 7 which are connected with the anode lead-out line 4 and a cathode layer of the capacitor element 2, respectively, are formed, in such a manner that parts of the respective terminals are exposed at least on a mounting surface of the chip-type solid electrolytic capacitor. In the capacitor, a plurality of upright parts 15, 16 which are formed, so as to rise up from opposite end portions of an anode terminal 6 are bent, a crossing part 17 is formed, and the anode lead-out line 4 of the capacitor element 1 is mounted on the crossing part 17. The crossing part 17 of the upright parts 15, 16 becomes the positioning reference of the anode lead-out line 4, so that positioning of the capacitor element 1 on a lead frame 11 is facilitated.

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 which can be used for high-density surface mounting mounted on various electronic devices.

[0002]

2. Description of the Related Art As a conventionally known chip type solid electrolytic capacitor, for example, FIG.
No. 8942. This chip-type solid electrolytic capacitor 51 is formed by molding and sintering a valve metal powder such as tantalum to form an oxide film serving as a dielectric by anodic oxidation on the surface of the anode body. A capacitor element 52 obtained by laminating a solid electrolyte layer such as manganese dioxide and a cathode layer made of carbon or silver paste on a lead frame having an anode lead 55 and a cathode lead 56; Have been.

A lead frame used for these chip-type solid electrolytic capacitors 51 is disclosed in, for example, Jpn.
No. 126 having a structure as shown in FIG. 5 or FIG. 6, wherein an anode lead wire derived from the capacitor element is welded to a lead frame of the anode, and the main body of the capacitor element has the cathode layer on its outer periphery. After bonding the part to the cathode lead frame with solder or the like, the capacitor element is resin-sealed by transfer molding with epoxy resin, etc., and the external lead formed by cutting the lead frame is bent along the exterior to form a chip An electrolytic capacitor is configured.

[0004] However, such a chip-type solid electrolytic capacitor 51 has an anode lead wire 54 and an anode lead 55.
Is welded to the resin 53, so that the volume occupied by the capacitor element 52 with respect to the entire size of the capacitor is small, so that there is a demand for a small and large-capacity chip-type solid electrolytic capacitor. It was not enough to deal with it.

[0005] For this reason, FIG.
Chip solid electrolytic capacitor 61 having a structure as shown in FIG.
It has been known. This chip type solid electrolytic capacitor 61
Has a structure in which the external electrodes 65 and 66 are provided on the mounting surface of the chip-type solid electrolytic capacitor, and the external electrodes 65 and 66 and the anode lead wire 64 of the capacitor element 62 are connected via a conductive auxiliary lead wire 69. Things.

In the chip type solid electrolytic capacitor having the structure shown in FIG. 4, the volume occupied by the capacitor element is larger than that of the conventional chip type solid electrolytic capacitor, and the volume efficiency can be improved.

[0007]

In the process of manufacturing a chip-type solid electrolytic capacitor as shown in FIG. 4, there is no positioning reference when mounting a capacitor element on the external electrodes 65 and 66. There is a possibility that the placement position of the capacitor element varies. Therefore, it is necessary to increase the margin of the resin layer to be molded, which has been a factor that hinders miniaturization of the chip-type solid electrolytic capacitor. In addition, since the auxiliary lead wire 69 is provided inside the capacitor, not only the internal structure becomes complicated, but also the number of components increases, so that the manufacturing process becomes complicated.

Accordingly, the present invention has been made in view of the above-described problems, and provides a structure of a chip-type solid electrolytic capacitor that can be further downsized and the manufacturing process can be simplified. Things.

[0009]

Therefore, according to the present invention, a dielectric oxide film is formed on the surface of an anode body in which a bar-shaped anode lead wire is buried, and an electrolyte layer and a cathode layer are successively formed. A capacitor element having an outer periphery serving as the cathode layer, comprising an exterior resin covering the capacitor element,
A chip-type solid electrolytic device formed by forming an anode terminal and a cathode terminal respectively connected to the anode lead wire and the cathode layer of the capacitor element so that a part of each terminal is exposed at least on the mounting surface of the chip-type solid electrolytic capacitor. In the capacitor, a plurality of upright portions formed so as to stand up from opposite ends of the anode terminal are bent to form an intersection by the upstanding portions, and an anode lead wire of the capacitor element is mounted on the intersection. The anode lead wire and the upright portion are electrically connected to each other.

A plurality of upright portions are formed so as to stand up from the opposite ends of the anode terminal, and the upright portions are bent so that the upright portions intersect with each other. Become a reference. Therefore, the position of the capacitor element with respect to the anode terminal can be fixed. In addition, the structure that obtains an electrical connection between the anode lead-out line of the capacitor element and the anode terminal by the upstanding portion that is continuous with the anode terminal reduces the number of parts and makes the manufacturing process of the chip-type solid electrolytic capacitor simple. Become.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1A and 1B are cross-sectional views illustrating a chip-type solid electrolytic capacitor according to the present embodiment, in which FIG. 1A is a view from a front view, and FIG. 1B is a view from a side.

[0012] Chip type solid electrolytic capacitor 1 of the present embodiment
As shown in FIG. 1, a capacitor element 2 having an anode lead wire 4 led out from one side, an anode terminal 5, and a side facing the anode terminal 5 and the capacitor element 2, 2, a cathode terminal 6 electrically and mechanically joined to the lower surface of the outer periphery of the capacitor element 2 by a conductive adhesive 7 and an exposed portion of the anode terminal 5 and the cathode terminal 6. And an exterior resin 3 that covers the capacitor element 2 so as to cover the capacitor element 2.

As the capacitor element 2, an element conventionally used as a solid electrolytic capacitor element, for example, an anode body obtained by molding and sintering a valve metal powder such as tantalum is added to a high-purity tantalum element. A rod-shaped anode lead-out wire 4 composed of Then, on the surface of the anode body, form an oxide film that becomes a dielectric by anodic oxidation,
A capacitor element or the like obtained by laminating a solid electrolyte layer such as manganese dioxide and a cathode layer made of carbon or silver paste on this oxide film can be suitably used. In addition, those using a conductive polymer such as polypyrrole as the solid electrolyte can also be used.

The anode terminal 5 used in this embodiment is
From each of the opposite sides of the anode terminal 5,
And a plurality of upright portions 15 and 16 provided so as to stand up with respect to the anode terminal 5. The upright portions 15 and 16 are each bent, and the upright portions 1 and 16 are bent.
5 and 16 intersect each other, and an intersection 17 is formed.

The capacitor element 2 is placed on the anode terminal 5, and the anode lead 4 of the capacitor element 2 is placed on the intersection 17. Also,
Since the anode terminal 5 is arranged on the lower surface of the capacitor element 2, when the lower surface of the capacitor element 2 comes into contact with the anode terminal 5, the anode terminal 5 is interposed via the cathode layer formed on the surface of the capacitor element 2. The insulating resin 9 is provided on the upper surface of the anode terminal 5 so that the insulating resin 9 is interposed between the capacitor terminal 2 and the lower surface of the capacitor element 2 due to the short circuit between the anode terminal 5 and the cathode terminal 6.

Hereinafter, the chip-type solid electrolytic capacitor 1 of this embodiment will be described along with its manufacturing steps. First, in this embodiment, the anode terminal 5 and the cathode terminal 6 have a shape as shown in FIG. 1 and are formed by a lead frame 11 on which a plurality of capacitor elements 2 can be mounted.
The lead frame 11 used in the chip-type solid electrolytic capacitor of this embodiment uses 42 alloy, which is an iron alloy containing 42% nickel, as a material. Further, the shape is as shown in FIG. 2, and two upright portions 15 and 16 are cut and raised continuously to a portion to be an anode terminal by pressing or bending a plate-like metal plate. ing. Then, the two upright portions 15 and 16 are bent so as to intersect with each other to form an intersection 17. When the upright portions 15 and 16 are formed by bending a part of the lead frame 11, the upright portions 15 and 16 can be formed simultaneously with the step of pressing the lead frame 11 from a plate-like metal. Since it is possible, the working process is simplified, which is preferable. At this time, if the shape of the upright portions 15 and 16 formed on the lead frame 11 is uniform, the position of the intersection 17 is also constant. The height of the intersection 17 between the upright portions 15 and 16 is determined by the anode lead wire 4 of the capacitor element 2 when the capacitor element 2 described later is mounted on the lead frame 11.
It is formed at the same height as the height.

The lead frame 1 shown in FIG.
Reference numeral 1 denotes only a peripheral portion of the mounted capacitor element, and a lead frame actually used is one in which the lead frame 11 shown in FIG. ing.

First, a coating material is applied to the upper surface of the portion to be the anode terminal 5 of the lead frame 11 and dried to form an insulating resin 9. As a method of applying these paints, a method is used in which the paints are applied to the corresponding portions of the lead frame 11 using an inkjet nozzle so that the thickness of the insulating resin 9 becomes a thickness that provides sufficient insulating properties, and the coating is dried and formed. However, the present invention is not limited to this, and any method can be used for forming the insulating resin 9.

In the application and drying by the ink jet nozzle, application and drying are repeatedly performed a plurality of times so that a good insulating resin layer without pinholes can be formed.

Further, as the insulating resin 9, since a relatively thick coating film can be easily obtained from the height of the solid content of the resin as well as the efficiency of the drying process, an ultraviolet curable resin is used in this embodiment. Although used, the invention is not so limited.

After the formation of the insulating resin 9, the cathode terminal 6
The conductive adhesive 7 is applied on the upper surface of the portion to be formed, and the capacitor element 2 is placed after the application.

As the conductive adhesive 7, since the cathode layer made of carbon or silver paste is exposed on the lower surface of the capacitor element 2 to be connected as described above, the viewpoint of adhesiveness with these cathode layers and the like is considered. Therefore, a silver-based conductive adhesive 7, which is usually used for mounting ICs or the like, is preferably used. However, the present invention is not limited to this. A paste or the like may be applied, and after the capacitor element 2 is mounted, the solder paste may be melted to fix and mount the capacitor element 2.

Capacitor element 2 to lead frame 11
At the time of mounting, the intersection 17 of the upright portions 15 and 16 serves as a reference for positioning the capacitor element 2 with respect to the lead frame 11. When the capacitor element 2 is mounted on the lead frame 11, the lateral movement of the anode lead wire 4 is restricted,
The anode lead wire 4 of the capacitor element 2 is placed at the intersection 17 while being guided by the upright portions 15 and 16. Positioning of the capacitor element 2 with respect to the lead frame 11 becomes easy. Also, the height of the intersection 17 is
Element 2 placed on lead frame 11
Is formed at the same height as the height of the anode lead wire 4, when the anode lead wire 4 is placed at the intersection 17, the bottom surface of the capacitor element 2 contacts the insulating resin 9 of the anode terminal 5. It comes to be placed in contact with it.

After the capacitor element is mounted on the lead frame, the anode lead wire and the upright portion of the anode terminal are electrically joined. The joining can be performed by a method such as resistance welding or laser welding.

Further, the capacitor element 2 is fixed by drying or curing the conductive adhesive 7.

Next, the entirety of the capacitor element and the lead frame 11 are covered with a sealing resin to be the exterior resin 3, and the exterior resin 3 is cured.

As the exterior resin 3, an epoxy resin such as epoxy acrylate, which is a molding resin used in the conventional transfer mold molding, can be suitably used, and a heat resistant material capable of withstanding soldering heat during board mounting. Any resin can be suitably used as long as it has properties and can obtain a liquid state at an appropriate heating state or normal temperature.

After the exterior resin 3 has been appropriately cured, a continuous body of chip-type solid electrolytic capacitors is cut out at predetermined positions to obtain individual chip-type solid electrolytic capacitors 1.

Although the present invention has been described with reference to the drawings, the present invention is not limited to the above-described embodiments, and changes and additions may be made without departing from the spirit of the present invention. Needless to say, this is included in the present invention.

[0030]

According to the present invention, a dielectric oxide film is formed on the surface of an anode body in which a bar-shaped anode lead wire is buried, and an electrolyte layer and a cathode layer are successively formed. A capacitor element, and an exterior resin covering the capacitor element, the anode lead wire of the capacitor element and an anode terminal and a cathode terminal respectively connected to the cathode layer, and a part of each terminal is at least a chip. In a chip-type solid electrolytic capacitor formed so as to be exposed on the mounting surface of the solid-state electrolytic capacitor, a plurality of upright portions continuous with the anode terminal are formed, and the upright portions intersect with each other. Since the anode lead-out line of the capacitor element is placed at the intersection, the intersection of the upright portion serves as a reference for positioning the anode lead-out line of the capacitor element. Therefore, the position of the capacitor element with respect to the anode terminal can be made constant.

Therefore, there is no variation in the mounting position of the capacitor element, and it is not necessary to provide a large margin for the resin layer to be molded. As a result, the size of the chip-type solid electrolytic capacitor can be reduced.

In addition, the upright portion connected to the anode terminal provides an electrical connection between the anode lead wire of the capacitor element and the anode terminal, so that the number of parts is reduced and the manufacturing process of the chip-type solid electrolytic capacitor is simplified. Becomes

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an internal structure of a chip-type solid electrolytic capacitor of the present invention, wherein FIG.
(B) is the figure seen from the side.

FIG. 2 is a perspective view showing a lead frame used in the present invention.

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]

 DESCRIPTION OF SYMBOLS 1 Chip-type solid electrolytic capacitor 2 Capacitor element 3 Outer resin 4 Anode lead-out line 5 Anode terminal 6 Cathode terminal 7 Conductive adhesive material 9 Insulating resin 11 Lead frame 15 Standing part 16 Standing part 17 Intersection 51 Chip-type solid electrolytic capacitor 53 Exterior Resin 54 Anode lead wire 55 Anode terminal 56 Cathode terminal 61 Chip type solid electrolytic capacitor 63 Exterior resin 64 Anode lead wire 65 Anode terminal 66 Cathode terminal 69 Auxiliary lead wire

Claims (1)

[Claims] 1. A capacitor in which a dielectric oxide film is formed on the surface of an anode body in which a bar-shaped anode lead wire is buried, and an electrolyte layer and a cathode layer are sequentially laminated and the outer periphery thereof is the cathode layer. Element, and an exterior resin covering the capacitor element, the anode terminal and the cathode terminal respectively connected to the anode lead wire and the cathode layer of the capacitor element, and a part of each terminal is at least a chip type solid electrolytic capacitor. In the chip-type solid electrolytic capacitor formed so as to be exposed on the mounting surface, a plurality of upright portions formed so as to stand up from opposing ends of the anode terminal are bent to form an intersection by the upright portions. A chip-type solid electrolytic capacitor formed and mounting an anode lead-out line of the capacitor element at the intersection and electrically connecting the anode lead-out line and the upright part.