JP2003197486A - Chip solid electrolytic capacitor and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain a groove cutting process from becoming complicated and to eliminate adverse effects caused by burrs produced in the groove-cutting process. <P>SOLUTION: A dielectric oxide film, an electrolytic layer, and a cathode layer are successively laminated on the surface of an anode body for the formation of a capacitor element 2, whose outer surface serves as the cathode layer, wherein the anode body is equipped with an anode lead wire 4 and formed of valve action metal. The capacitor elements 2 are mounted on a lead frame 11, equipped with a plurality of repetitive units each provided with an anode terminal 5 connected to the anode lead wire 4 of the capacitor element 2 and a cathode terminal 6 connected to the cathode layer of the capacitor element 2. The capacitor elements 2 mounted on the lead frame 11, the anode terminals 5, and the cathode terminals 6 are coated with a sheathing resin 3 so as to make the terminals 5 and 6 partially exposed. The repetitive units of the lead frame 11, where the capacitor elements 2 covered with the sheathing resin 3 are located inside, are cut into prescribed shapes to obtain chip solid electrolytic capacitors 1. A groove 29 is provided to the lead frame 11 so as to enable the corresponding parts serving as the end side corners of the anode terminal 5 and the cathode terminal 6 by cutting to be cutouts 7 and 7'. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a chip type solid electrolytic capacitor which can be used for high density surface mounting mounted on various electronic devices and a manufacturing method thereof.

[0002]

2. Description of the Related Art A chip-type solid electrolytic capacitor usable for these high-density surface mounting is disclosed in Japanese Patent Laid-Open No. 2001-69.
As proposed in Japanese Patent Publication No. 78, a dielectric oxide film and an electrolyte layer are sequentially laminated on the surface of an anode body made of a valve metal, which has an anode lead wire, and the outer periphery of the anode body serves as the cathode layer. Mounting step of mounting the capacitor element on a lead frame having a plurality of repeating units each having an anode terminal connected to an anode lead wire of the capacitor element and a cathode terminal connected to the cathode layer, and mounting on the lead frame A coating step of coating the capacitor element and the anode terminal and the cathode terminal with an exterior resin so that a part of each electrode terminal is exposed; and the inside of the capacitor element coated with the exterior resin There is known a method for manufacturing a chip type solid electrolytic capacitor including a cutting step of cutting a repeating unit of the lead frame into a predetermined shape.

In the chip type solid electrolytic capacitor obtained by the above-mentioned manufacturing method, the metal burrs such as the lead frame in the cutting step may project toward the lower surface of the anode terminal and the cathode terminal. Therefore, in mounting the chip type solid electrolytic capacitor, there are problems that the anode terminal and the cathode terminal are not soldered well, and the chip type solid electrolytic capacitor is misaligned, and these problems are solved. For this reason, the present applicants have previously filed 2001-
As proposed in Japanese Patent No. 286923, a method has been proposed for solving the problems caused by these burrs by performing a groove portion for accommodating the burrs prior to the cutting process.

[0004]

It is very useful to perform the above-mentioned groove portions prior to the cutting work, because the influence of burrs generated in the cutting work can be almost eliminated, and the groove portions described above are highly useful. The groove machining step for carrying out the machining is required, which complicates the process, and some burrs are generated in the lower surface direction of the anode terminal and the cathode terminal also in the groove machining step, and these burrs are generated. There is a problem that it may adversely affect the soldering of the anode terminal and the cathode terminal.

Therefore, the present invention has been made by paying attention to the above-mentioned problems, and a chip type solid electrolytic capacitor capable of eliminating the adverse effects due to the complication of the groove processing step and burrs generated in the groove processing step. And its manufacturing method.

[0006]

In order to solve the above problems, a chip type solid electrolytic capacitor of the present invention has an anode lead wire and a dielectric oxide film on the surface of an anode body made of valve metal. An electrolytic layer and a cathode layer are sequentially laminated and formed, and a capacitor element whose outer periphery is the cathode layer is connected to an anode terminal connected to an anode lead wire of the capacitor element and a cathode layer of the capacitor element. It is mounted on a lead frame having a plurality of repeating units each including a cathode terminal, and the capacitor element, the anode terminal, and the cathode terminal mounted on the lead frame are covered with an exterior resin so that a part of each pole terminal is exposed. Obtained by cutting the repeating unit of the lead frame in which the capacitor element covered with the exterior resin is formed into a predetermined shape. A chip type solid electrolytic capacitor, characterized in that the lead frame is provided with a groove portion for making a portion which becomes an end side corner portion of the anode terminal and the cathode terminal by the cutting into a notch shape. There is. According to this feature, the groove portion which was conventionally formed by the groove processing is previously processed on the lead frame, so that the groove processing step can be omitted and the groove processing can be simplified. It is also possible to eliminate the adverse effects of burrs that occur in the process.

According to the method of manufacturing a chip type solid electrolytic capacitor of the present invention, a dielectric oxide film, an electrolyte layer and a cathode layer are sequentially laminated on the surface of an anode body having an anode lead wire and made of a valve metal. A lead having a plurality of repeating units including a capacitor element whose outer periphery is the cathode layer, an anode terminal connected to an anode lead wire of the capacitor element, and a cathode terminal connected to the cathode layer of the capacitor element. A mounting step of mounting on a frame; a coating step of coating the capacitor element, the anode terminal and the cathode terminal mounted on the lead frame with an exterior resin so that a part of each pole terminal is exposed; A chip type including a cutting step of cutting the repeating unit of the lead frame in which the capacitor element covered with the exterior resin is embedded into a predetermined shape. A method of manufacturing a body electrolytic capacitor, wherein the lead frame is provided with a groove portion for cutting out portions of the anode terminal and the cathode terminal, which are corner portions of the side edges, by cutting in the cutting step. It is characterized by that. According to this feature, the groove portion which was conventionally formed by the groove processing is previously processed on the lead frame, so that the groove processing step can be omitted and the groove processing can be simplified. It is also possible to eliminate the adverse effects of burrs that occur in the process.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

(Example)

FIG. 1 is a perspective view showing the structure of the chip type solid electrolytic capacitor of this embodiment, and FIG. 2 is a sectional view showing the chip type solid electrolytic capacitor of this embodiment.
[FIG. 6] is a diagram showing a shape of a lead frame used in this example.

Chip type solid electrolytic capacitor 1 of the present embodiment
As shown in FIG. 1, the capacitor element 2 and the anode lead wire 4 led out from one side surface of the capacitor element 2 come into contact with each other by being bent, and are welded to the outer periphery of the anode lead wire 4 by welding. An anode terminal 5 provided with a tongue portion 8 to be connected to the anode terminal 5 is disposed below the capacitor element 2 on the side facing the anode terminal 5 with the capacitor element 2 interposed therebetween.
The capacitor element 2 is connected to the lower surface of the outer peripheral portion of the capacitor element 2 electrically and mechanically with a conductive adhesive 10 and the cathode terminal 6 and a portion except the exposed portions of the anode terminal 5 and the cathode terminal 6. Exterior resin 3 to cover
It is mainly composed of and.

As shown in FIG. 3, the anode terminal 5 used in this embodiment has a tongue portion 8 formed in a ribbon shape so as to project laterally from the region where the capacitor element 2 is mounted. Is formed in such a length that the tongue portion 8 can be brought into contact with the anode lead wire 4 by bending the tongue portion 8 from the lead-out portion of the projecting portion, and the lower surface of the capacitor element 2 and the anode terminal to be mounted. When the upper surface of the capacitor element 5 comes into contact with the upper surface of the capacitor element 2, the anode terminal 5 and the negative electrode terminal 6 are short-circuited via the cathode layer formed on the surface of the capacitor element 2, so that insulation is provided between the lower surface of the capacitor element 2. So that the resin 9 intervenes,
An insulating resin 9 is provided on the upper surface.

The capacitor element 2 is an element which has been conventionally used as a solid electrolytic capacitor element, for example, anodized on the surface of a sintered body obtained by molding and sintering valve metal powder such as tantalum. To form a dielectric oxide film as an anode body, and 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 the anode body. It can be used preferably. still,
As the solid electrolyte, those using a polymer electrolyte such as polypyrrole can also be used.

In this embodiment, the anode terminal 5, the tongue portion 8 and the cathode terminal 6 are shaped as shown in FIG.
A plurality of repeating units each consisting of a pair of anode terminal 5 and cathode terminal 6 are arranged to form a lead frame 11 on which a plurality of capacitor elements 2 can be mounted, and the bottom surfaces of these anode terminals 5 and cathode terminals 6 are formed. At the predetermined position, the groove portion 2 which becomes the cutout portions 7 and 7'shown in FIG. 2 by the final cutting.
9 is formed, and in this embodiment, 3 × 5 = 15 repeating units including the anode terminal 5 and the cathode terminal 6 in which the groove portions 29 are formed are arranged and the sealing resin 3 is formed.
And a sealing unit 3 which is a sealing region to be sealed at the same time is sealed with the sealing resin 3 without a gap, and the sealing region which is the sealing unit is a lead frame. 11 are repeatedly arranged in the longitudinal direction.

Further, in the lead frame 11 of the present embodiment, as shown in FIG. 3, a cutting guide serving as a guide for cutting lines 34 and 35 for facilitating cutting is provided at an outer peripheral position surrounding the set unit. With the holes 32,
At the outer peripheral position of the cutting guide hole 32, the through holes 30, 3 are formed.
1 is provided, and by providing these through holes 30 and 31, when the lead frame 11 is cut, particularly when the outer peripheral parts 11a and 11b of the set unit shown in FIG. 3 are cut, these outer peripheral parts are provided. It becomes difficult for vibration and mechanical stress (stress) in the cutting of the capacitor to be transmitted to the lead frame 11 and the capacitor element 2 included in the set unit, and the cathode terminal 6 is detached and the capacitor element 2 and Although it is possible to avoid deterioration of electrical connection characteristics with the cathode terminal 6, it is preferable.
The present invention is not limited to this.

The chip type solid electrolytic capacitor 1 of this embodiment will be described below along with its manufacturing process. First, as shown in FIG. 4A, a coating material is applied and dried on the upper surface of the portion of the lead frame 11 to be the anode terminal 5, and the insulating resin 9 is formed. In the present embodiment, as a method of applying these paints, an ink jet nozzle (not shown) is used to apply the paint to the relevant portion of the lead frame 11 so that the thickness of the insulating resin 9 is a thickness that provides sufficient insulation. However, the present invention is not limited to this, and any method can be used as a method of forming these insulating resins 9.

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

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

After the insulating resin 9 is formed, as shown in FIG.
As shown in FIG. 4, the conductive adhesive 10 is applied and formed on the upper surface of the portion to be the cathode terminal 6, and after the application, the capacitor element 2 is mounted as shown in FIG. 4C.

In these conductive adhesives 10, since the lower surface of the capacitor element 2 to be connected exposes the cathode layer made of carbon or silver paste as described above,
From the viewpoint of adhesion to these cathode layers, etc.
The silver-based conductive adhesive 10 used for mounting C or the like is preferably used, but the present invention is not limited to this, and a solder paste or the like is applied instead of the conductive adhesive 10. Then, after mounting the capacitor element 2, the solder paste is melted to fix the capacitor element 2,
It may be mounted.

After mounting these capacitor elements 2, the conductive adhesive 10 is dried or cured to fix the capacitor elements 2, and after the fixing, as shown in FIG. The tongue portion 8 formed by leading out is bent toward the mounting side of the capacitor element 2 and brought into contact with the anode lead wire 4, and the anode lead wire 4 and the tongue portion 8 are formed.
And are connected by welding to electrically connect the anode lead wire 4 to the anode terminal 5.

Next, as shown in FIG. 4 (e), the lead frame 11 on which the capacitor element 2 is mounted is mounted on a ferrite plate 19 which is a flat plate with the non-mounting surface of the capacitor element 2 of the lead frame 11 as the lower surface. And the lower surface and the upper surface of the ferrite plate 19 are brought into contact with each other, and a sealing resin serving as an exterior resin 3 is entirely provided from the mounting side of the lead frame 11 on which the capacitor element 2 is mounted. Is poured into the lead frame 1 so as to have a predetermined thickness so as to be covered with the exterior resin 3.
The exterior atmosphere of No. 1 is made to be a vacuum, so that the exterior resin 3 is filled up to a fine region inside, and then the exterior resin 3 is cured.

As described above, it is preferable to make the external atmosphere a vacuum because the outer resin 3 can be quickly filled even in a fine area inside, but the present invention is not limited to this.

As the exterior resin 3, an epoxy resin such as epoxy acrylate, which is a molding resin used in conventional transfer molding, can be preferably used, and at the same time, a heat resistance that can withstand soldering heat during mounting on a substrate. Any resin having properties and capable of obtaining a liquid state at an appropriate heating state or room temperature can be suitably used.

Further, in the present embodiment, as described above, the lead frame 11 on which the capacitor element 2 is mounted is placed on the ferrite plate 19 which is a magnetic body and has high heat resistance to form the exterior resin 3. I am pouring the sealing resin,
This is preferable because the flat ferrite plate 19 can regulate the outflow amount of the sealing resin to the lower surface of the lead frame 11 and reduce the size of the protruding portion 3 ′ of the exterior resin. However, the present embodiment is not limited to this, and these ferrite plates 19
Instead of this, a heat resistant film may be attached to form the exterior resin 3, or the lead frame 11 may be arranged inside the mold to form the exterior resin 3.

It should be noted that it is optional to apply a release agent or the like to the upper surface of the ferrite plate 19 to prevent the adhesion with the exterior resin 3.

After the exterior resin 3 is appropriately cured, as shown in FIG. 5 (f), the lead frame 11 sealed with the sealing resin is peeled off from the ferrite plate 19, and then the exterior resin 3 is removed. The protruding portion 3 ′ and the lead frame 11 are ground from the lower surface of the lead frame 11 using an elastic polishing body. In this embodiment, as the elastic polishing body, the outer periphery of the side surface of the elastic polishing body is brought into contact with the lower surface of the lead frame 11 for polishing, but the present invention is not limited to this. A disk-shaped body may be used, and the disk surface may be brought into contact with the lower surface of the lead frame 11 and polished.

As described above, not only the protruding portion 3'of the exterior resin but also the entire lower surface of the lead frame 11 is thinly ground so that the lead frame 11 before resin sealing has high strength. It becomes possible to use a thick lead frame which is hard to warp and has excellent handleability, which can improve workability, and the volume ratio of the lead frame 11 in the obtained capacitor can be reduced by making the entire lower surface of the lead frame 11 thin. The volume ratio of the capacitor element 2 occupying in the capacitor can be made higher since it can be reduced as compared with the case where it is not ground and a larger (higher) capacitor element 2 can be mounted. Although preferred, this embodiment is not so limited.

After these grinding steps, as shown in FIG. 5 (g), the exposed portion of the lead frame 11 is plated with a metal such as solder plating 14 which can improve the wettability with the solder, and then the chip-type solid On the surface opposite to the exposed surface of the lead frame 11 corresponding to the upper surface of the electrolytic capacitor 1,
As shown in (h), the dicing tape 15 is attached.

After the dicing tape 15 is adhered, as shown in FIG. 5 (i), the exterior resin that has penetrated into the groove portion 29 is cut from the groove portion 29 by, for example, cutting with a rotary blade. When 3 is removed, the metal burr of the lead frame 11 generated by the cutting is housed in the notches 7 and 7'formed by the groove 29, and these cutting lines (cutting grooves) are formed. After forming 35, the chip-type solid electrolytic capacitor 1 of the present invention is obtained by cutting in the vertical direction.

As in the present embodiment, by forming the groove portions 29 in the anode terminal 5 and the cathode terminal 6 of the lead frame 11 in advance, groove processing for forming the cutout portions 7 and 7 '. It is not necessary to carry out the above in the process, and not only the process can be simplified but also the metal burr of the lead frame 11 is provided with the notch portion 7 formed in the groove 29
Since it is housed in 7 ', the adverse effect of these burrs can be eliminated.

The present invention has been described above with reference to the drawings. However, the present invention is not limited to the above-mentioned embodiments, and even if there are changes and additions within the scope not departing from the gist of the present invention, Needless to say, it is included in the present invention.

For example, in the above embodiment, 1 is set in the set unit.
Although it is designed to incorporate five capacitor elements 2,
The present invention is not limited to this, and it is also possible to incorporate 4, 6, or 9 capacitor elements 2 in these set units, and the number of these elements depends on the shape and size of the set unit. It may be selected appropriately.

In the above embodiment, the tongue portion 8 is used to connect the anode lead wire 4 and the anode terminal 5, but the present invention is not limited to this, and the anode terminal 5 is not limited to this.
Is formed into an L-shape in cross-section so that it can be brought into contact with the lower end of the anode lead wire 4, or a pillow-shaped connecting member is arranged between the anode terminal 5 and the anode lead wire 4 for connection. The connection method between the anode lead wire 4 and the anode terminal 5 may be appropriately selected.

[0035]

The present invention has the following effects.

(A) According to the first aspect of the present invention, the groove portion which was conventionally formed by groove processing is previously processed in the lead frame, whereby the groove processing step can be omitted, Not only can it be simplified, but it is also possible to eliminate the adverse effects of burrs that occur in the groove processing process.

(B) According to the invention of claim 2, the groove portion which was conventionally formed by groove processing is previously processed in the lead frame, so that the groove processing step can be omitted, Not only can it be simplified, but it is also possible to eliminate the adverse effects of burrs that occur in the groove processing process.

[Brief description of drawings]

FIG. 1 is a perspective view showing a structure of a chip type solid electrolytic capacitor in an example of the present invention.

FIG. 2 is a cross-sectional view showing a chip type solid electrolytic capacitor in an example of the present invention.

FIG. 3 is a diagram showing a shape of a lead frame used in this embodiment of the present invention.

FIG. 4 is a diagram showing a manufacturing process of the chip-type solid electrolytic capacitor of the present invention.

FIG. 5 is a diagram showing a manufacturing process of the chip type solid electrolytic capacitor of the present invention.

[Explanation of symbols]

1 chip type solid electrolytic capacitor 2 Capacitor element 3 Exterior resin 3'Exterior resin (protruding part) 4 Anode lead wire 5 Anode terminal 6 cathode terminal 7 Notch (anode) 7'Notch (cathode) 8 tongue 9 Insulating resin 10 Conductive adhesive 11 lead frame 12 Elastic polishing body 13 recess 14 Solder plating 15 dicing tape 19 Ferrite plate (flat plate) 30 through holes 31 through hole 32 Cutting guide hole 34 Cutting line (groove) 35 Cutting line (groove)

Claims (2)

[Claims] 1. A capacitor having an anode lead wire and a dielectric oxide film, an electrolyte layer, and a cathode layer, which are sequentially laminated on the surface of an anode body made of a valve metal, the outer periphery of which serves as the cathode layer. The element is mounted on a lead frame having a plurality of repeating units each having an anode terminal connected to the anode lead wire of the capacitor element and a cathode terminal connected to the cathode layer of the capacitor element, and mounted on the lead frame. The capacitor element, the anode terminal, and the cathode terminal are coated with an exterior resin so that a part of each electrode terminal is exposed, and the lead frame in which the capacitor element coated with the exterior resin is contained. Is a chip-type solid electrolytic capacitor obtained by cutting the repeating unit of the above into a predetermined shape. A chip-type solid electrolytic capacitor, characterized in that a groove portion is provided for forming a notch-like portion at the end side corner portion of the terminal and the cathode terminal. 2. A capacitor having an anode lead wire and a dielectric oxide film, an electrolyte layer and a cathode layer which are sequentially laminated on the surface of an anode body made of a valve metal, and the outer periphery of which is the cathode layer. A mounting step of mounting an element on a lead frame having a plurality of repeating units each including an anode terminal connected to an anode lead wire of the capacitor element and a cathode terminal connected to a cathode layer of the capacitor element, and the lead frame. A coating step of coating the capacitor element and the anode terminal and the cathode terminal mounted on a casing with an exterior resin so that a part of each electrode terminal is exposed; and the capacitor element coated with the exterior resin. A method for manufacturing a chip-type solid electrolytic capacitor, comprising: a cutting step of cutting an internal repeating unit of the lead frame into a predetermined shape. Manufacturing of a chip-type solid electrolytic capacitor, characterized in that the frame is provided with a groove portion for cutting out portions of the anode terminal and the cathode terminal, which are corners of the side edges, by cutting in the cutting step. Method.