JPH0419778Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a composite capacitor in which three capacitors are integrated and a third external electrode made of a metal foil electrode is provided on the outer peripheral surface of the capacitor element. The present invention relates to a composite capacitor in which manufacturing workability is improved by forming a laminate of a foil electrode and a dielectric film, and further forming a thermoplastic adhesive layer on the inner surface of the laminate.

[Prior Art] Conventionally, in order to remove high-frequency noise applied to electronic devices, a noise filter has been configured using a capacitor as shown in FIG. 5A, or by combining a capacitor and a coil as shown in FIG. 5B. This is incorporated into the circuit and used. Among the components that make up the noise filter, the three capacitors C ₁ , C ₂ and C ₃ , which are connected between the lines of the circuit and between the line and the ground, respectively, are widely used as the basic components of the noise filter. Various composite capacitors have been devised in which these are integrated by delta connection, and the present applicant has already proposed a composite capacitor equipped with a third external electrode made of a metal foil electrode (Utility Application No. 115450-1981). ing.

That is, as shown in FIG. 6, the above composite capacitor has a pair of metalized dielectric films 4, 4 stacked on top of each other, and a metal foil electrode 6 sandwiched between the pair of dielectric films 5, 5'. A capacitor element 8 is formed by stacking a metal foil electrode 6 and a dielectric film 5 and winding them together.
is formed. Although not shown, metallization is applied to both end surfaces of the capacitor element 8 to form first and second external electrodes, and the terminal end of the metal foil electrode 6 is wound around the outer peripheral surface of the capacitor element 8. It has a structure in which it is rotated to form a third external electrode.

The composite capacitor 1 has a first external electrode and a second external electrode.
Since a capacitance is formed between the external electrode of the external electrode and the third external electrode and each of the first and second external electrodes, and a total of three capacitors are integrated, it is small and can be installed in a small space. In addition, it is easy to incorporate into the circuit, and since the third external electrode is formed on the outer peripheral surface of the capacitor element, it is easy to lead out the external terminal. .

[Problems to be solved by the invention] However, in the composite capacitor having the above-mentioned configuration, the number of sheets of material wound to form the third external electrode increases, making the winding work complicated.
Furthermore, in order to terminate the winding of a capacitor element, it is necessary to apply adhesive to the inner surface of the metal foil electrode and fix it to the outer circumferential surface of the capacitor element at the end of the winding process, which makes the process complicated. There's a problem.

This invention was devised in view of the above points,
The object of the present invention is to realize a composite capacitor that is small in size and easy to incorporate into a circuit, has external terminals easily drawn out, and has easy winding work and winding termination work.

[Means for Solving the Problems] In order to solve the above problems, the present invention forms a thermoplastic adhesive layer on the inner surface of a laminate made by laminating and integrating a dielectric film and a metal foil electrode in advance, This is stacked and wound with a metallized dielectric film to form a capacitor element, and first and second external electrodes are respectively formed on both end surfaces of the capacitor element, and the The gist of the present invention is a composite capacitor in which a winding terminal end of a laminate is arranged on the outer peripheral surface of a capacitor element to form a third external electrode.

[Function] Since the present invention has the above-mentioned configuration, the number of sheets of material to be wound is reduced, and if the capacitor element is heated at the end of the winding operation, the thermoplastic adhesive layer forms a laminate. The end of the winding is fixed to the outer peripheral surface of the capacitor element, and capacitance is formed between the first, second, and third external electrodes, and the three capacitors are integrated in a delta-connected state. . Therefore, when mounting this composite capacitor in a circuit, by connecting the first and second external electrodes to each line of the circuit and the third external electrode to the ground, the connection between the lines of the circuit and between the line and the ground can be achieved. A capacitor is incorporated in each.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

[Example 1] Figs. 1 and 2 show a composite capacitor according to an embodiment of the present invention, in which Fig. 1A is an exploded side sectional view of the main part of a capacitor element, and Fig. 1B is a main part. The developed cross-sectional view and FIG. 2 are perspective views of the completed product. In the figure, a composite capacitor 1 is constructed of a pair of dielectric films 2 and 2' made of synthetic resin such as polyester or insulating paper such as capacitor paper, each made of metal such as aluminum except for the margin at one end. Vapor-deposited electrodes 3 and 3' are provided to form metallized dielectric films 4 and 4', which are wound so that the margin parts are arranged at different ends and overlapped with each other with a slight shift in the width direction. There is. Furthermore, during the winding process, a thermoplastic adhesive layer 7 such as rubber or resin adhesive is applied to the inner surface of the laminate 13 consisting of the dielectric film 5 and the metal foil electrode 6, that is, the surface that becomes the inner side when it is wound. A capacitor element 8 is formed by inserting the capacitor element 8 and winding the capacitor element 8 together.

The laminate 13 includes a dielectric film 5 having approximately the same width as the metallized dielectric films 4, 4'.
A metal foil electrode 6 made of aluminum foil, tin foil, etc. having a width narrower than that of the dielectric film 5 is overlaid approximately at the center in the width direction of the dielectric film 5, and is formed in advance by bonding or other means. Then, it is wound with the dielectric film 5 side on the inside and the metal foil electrode 6 side on the outside so that its terminal end is arranged on the outer circumferential surface of the capacitor element 8. At the end of winding, for example, a heating roller is applied. They are brought into contact with each other, heated, and bonded and fixed by a thermoplastic adhesive layer 7. In this state, the metal foil electrode 6 is exposed on the outer peripheral surface of the capacitor element 8 and is formed as a third external electrode 9. Further, as shown in FIG. 2, the capacitor element 8 is flattened by pressing, and a metallized coating such as solder is applied to both end surfaces by spraying metal such as solder to form a first external electrode 10 and a second external electrode 10'. do.

Therefore, between the first external electrode 10 and the second external electrode 10', between the second external electrode 10' and the third external electrode 9, and between the third external electrode 9 and the first external electrode The first, second and third electrodes are connected between the external electrode 10 and the external electrode 10.
The three capacitors C ₁ , C ₂ and C ₃ shown in FIGS. 5A and 5B are integrated in a delta connection.

In this case, at the starting end of the laminate 13,
There is a possibility that the metal foil electrode 6 and the vapor deposited electrode 3' of the metallized dielectric film 4' may be short-circuited, but even if a short circuit should occur, the short-circuited portion of the vapor deposited electrode 3' will be removed by the healing action. Therefore, there are no insulation problems. Although not shown, the metallized dielectric film 4' at the starting end of the laminate 13
If an insulating film is inserted between the laminate 13 and the laminate 13, or the metal foil electrode 6 at the starting end of the laminate 13 is removed in advance, insulation measures can be made more reliable.

[Embodiment 2] FIG. 3 shows another embodiment of the present invention, in which a dielectric film 5' is placed between the metal foil electrode 6 side of the laminate 13 and the metallized dielectric films 4, 4'. The other configurations are the same as in the first embodiment. In the case of this embodiment, the vapor-deposited electrodes 3, 3' at the end portions of the metallized dielectric films 4, 4' are removed by burn-off treatment, voltage treatment, etc., so that the dielectric film 5' does not exist. However, the dielectric film 5' strengthens the insulation between the metal foil electrode 6 connected to the ground and the metallized dielectric films 4, 4'. Therefore, the withstand voltage of the grounded capacitor can be improved.

The capacitance of the second and third capacitors in the embodiments described above can be determined by changing the opposing area between the metal foil electrode and the vapor-deposited electrode by changing the width and insertion position of the metal foil electrode. Can be adjusted.

As shown in FIG. 4, a composite capacitor formed by integrating three capacitors is provided with a first external electrode 10 and a second external electrode 1 as necessary.
Welding (not shown) or soldering a first external terminal 11 and a second external terminal 11' to 0', respectively.
Furthermore, a third external terminal 12 is soldered to the third external electrode 9 (not shown), or a third external terminal 12 is soldered to the third external electrode 9.
2 is made up of metal pieces formed into a substantially J-shape, which are sandwiched and connected, and then housed in a case and sealed with resin or coated with resin to form an exterior.
In this case, since the laminate 13 integrally formed with the third external electrode 9 is fixed to the outer peripheral surface of the capacitor element 8 by the thermoplastic adhesive layer 7, the connection with the third external terminal 12 is The properties will be good.

[Effects of the invention] As detailed above, the composite capacitor of the invention has the following effects:
Since three capacitors are integrated, it is small and easy to incorporate into a circuit. Furthermore, since a laminate is used in which a dielectric film and a metal foil electrode are laminated together, the number of sheets of material to be wound is reduced, simplifying the winding process. Since the end of the winding of the metal foil electrode is exposed on the outer circumferential surface of the capacitor element to serve as the third external electrode, it is easy to lead out the external terminal from the third external electrode, and it is also possible to This has various practical values, such as the laminate is fixed by simple heating without using any agent, and the end-of-winding process becomes easy.

[Brief explanation of the drawing]

1 to 4 show a composite capacitor according to the present invention. FIG. 1A is an exploded side cross-sectional view of the main part of a capacitor element in one embodiment, and FIG. 1B is an exploded cross-sectional view of the main part. Figure 2 is a perspective view of the finished product, Figure 3 is a perspective view of the finished product.
Figure A is an exploded side sectional view of the main part of a capacitor element in another embodiment, Figure 3B is an exploded cross-sectional view of the main part, and Figure 4 is a perspective view showing a state in which external terminals are connected. 5A and 5B are circuit diagrams incorporating a noise filter, and FIG. 6 is an exploded side sectional view of essential parts of a conventional capacitor element. 1... Composite capacitor, 4, 4'... Metallized dielectric film, 5, 5'... Dielectric film, 6
...Metal foil electrode, 7...Thermoplastic adhesive layer, 8...
... Capacitor element, 9 ... Third external electrode, 10
...first external electrode, 10'...second external electrode,
13...Laminated body.

Claims (1)

[Claims for Utility Model Registration] (1) Forming a thermoplastic adhesive layer on the inner surface of a laminate made by laminating and integrating a dielectric film and a metal foil electrode in advance, and layering this with a metallized dielectric film. A capacitor element is formed by winding the laminated body, first and second external electrodes are formed on both end faces of the capacitor element, and the winding end portion of the laminate is wound around the capacitor element so that the metal foil electrode is exposed. A composite capacitor comprising a third external electrode arranged on the outer peripheral surface of the capacitor. (2) The composite capacitor according to claim 1 of the utility model registration, characterized in that a dielectric film is disposed between the metal foil electrode side of the laminate and the metallized dielectric film.