JPH03183112A - Manufacture of leadless electrolytic capacitor - Google Patents

Abstract

PURPOSE:To surely bond a frame part to a capacitor main body and to be strongly resistant to a mechanical stress when a leadless electrolytic capacitor is mounted on a board by forming the frame part which is deformed along a cauked groove part of the capacitor main body by a heat treatment, which is hooked to and held at the lower-end part of the capacitor main body and which is composed of a synthetic resin or the like. CONSTITUTION:A frame part 9 which is composed of a thermoplastic synthetic resin such as polyether sulfone, polystyrene terephthalate, polyether ether ketone, an aromatic polyester, polyethylene terephthalate or the like is formed in a bottomed tube shape. One part of the side and one part of a caulked part at an outer package case 5 are covered with its side part; the bottom part is formed so as to cover the whole part at one end face of the capacitor main body 1. Since the frame part 9 and the capacitor main body 1 are fixed and bonded firmly by thermally deforming the frame part 9, a firmly fixed and bonded state can be realized as compared with a case where an insulating sheet or the like is arranged on an end face of the capacitor main body and a lead wire is bent, fixed and bonded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a leadless electrolytic capacitor without through holes and compatible with so-called face bonding substrates.

In recent years, as electronic devices have become smaller and lighter and manufacturing processes have been simplified, leadless electrolytic capacitors without lead wires have been required.

[Conventional technology]

In the conventional leadless electrolytic capacitor, as shown in the proposal shown in FIG. 2, the entire capacitor element 2 is covered with an exterior member 13 molded with synthetic resin, and the lead wire 15 led out from the capacitor element 2 body is , a lead portion bent from the side surface to the bottom surface of the exterior member 13! It was electrically connected to 4.

Furthermore, as seen in Japanese Patent Application No. 57-232484, it has been proposed to mold a synthetic resin into a part of the capacitor body including the sealing material.

This structure was necessary to make the electrolytic capacitor independent and to electrically connect the lead portion 14 to the wiring pattern on the printed circuit board.

[Problem to be solved by the invention]

However, when molding the entire capacitor element, major changes to the capacitor structure itself are required.
The manufacturing process is complicated, and the heat generated when covering the capacitor element 2 body with the exterior member 13 is
This is not necessarily easy to realize because it has a negative effect on the electrical characteristics of the device.

Furthermore, even when resin is molded into a part of the capacitor body, the heat generated by the molding has a negative effect on the internal capacitor element, and a part of the capacitor body must be covered with a mold for molding. This results in a difficult manufacturing process.

Also, for example, as in the invention of Japanese Patent Application No. 58-3838,
It has been proposed that an insulating plate is placed on the end face of the capacitor body, and lead wires are pulled out from through holes provided in the insulating plate and bent along the bottom face of the insulating plate. According to this invention, there is no need for molding as in the previous proposal. However, the capacitor body and the insulating plate are fixed together only by bending the lead wire, and depending on the mechanical strength of the lead wire, the insulating plate may separate from the capacitor body. Alternatively, the mechanical stress applied to the insulating plate may be applied to the lead wire, which may have an adverse electrical effect on the internal capacitor element.

The present invention solves the above drawbacks and provides a method for easily manufacturing a leadless electrolytic capacitor that can be mounted on a face bonding board without changing the structure of the conventional electrolytic capacitor itself. The purpose is to

[Means to solve the problem]

The present invention is a method for manufacturing a leadless electrolytic capacitor, which covers at least the entirety of one end face of an exterior case and a part or all of a caulking portion on a side surface of the exterior case on the end face side from which a lead wire is led out. It is characterized in that the frame portion is fitted, the frame portion is anchored to the caulking portion through heat treatment, and the lead wire led out from the capacitor element is bent along the outer bottom surface of the frame portion.

[For production]

The side surface of the frame made of synthetic resin covers part or all of the caulking part of the capacitor body, and is heat-treated to deform along the caulking groove of the capacitor body, and the lower end of the capacitor body to be moored.

Therefore, the frame portion is firmly anchored to the lower end portion of the capacitor body.

Further, the lead wires protruding from the bottom of the frame are bent in opposite directions along the bottom of the frame, forming a substantially flat surface on the bottom, and connecting the printed circuit board provided on the face bonding board. It will come into contact with the wiring.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view showing the completed state of a leadless electrolytic capacitor manufactured according to an embodiment of the present invention. Figure 3 is a perspective view showing the shape of the frame used in the example;
The figure is an explanatory diagram illustrating the process of manufacturing a leadless electrolytic capacitor according to an embodiment of the present invention.

As shown in FIG. 1, the capacitor body 1 includes an electrode foil 3 and an electrolytic paper 4 wound around it, and a capacitor element 2 impregnated with an electrolyte solution, which is housed in an exterior case 5 made of aluminum or the like. A sealing member 8 made of elastic rubber or the like is formed to seal the opening of the exterior case 5.

Lead wires 6 , 7 for drawing out electrodes led out from the capacitor element 2 penetrate the sealing body 8 and protrude to the outside from the end surface of the capacitor body 1 .

polyether sulfone, polyethylene terephthalate,
As shown in FIG. 3, the frame portion 9 made of a thermoplastic synthetic resin such as polyetheretherketone, aromatic polyester, or polyethylene terephthalate is formed into a cylindrical shape with a bottom. The side surface part is formed to cover a part of the side surface of the outer case 5 and a part of the caulking part, and the bottom part is formed to cover the whole of one end surface of the capacitor body l. In addition, a through hole 10 is formed in the bottom of the frame portion 9, through which the lead wires 6 and 7 led from the capacitor body l are inserted, and the lead wires 6 and 7 are bent on the outer surface. A groove portion 1) into which the groove is inserted is provided.

This frame portion 9 is fitted onto the lower end surface of the capacitor main body l, and the fourth
As shown in the figure, lead wires 6.7 led out from the capacitor body 1 are made to protrude outside through a through hole 10 formed in the bottom surface of the frame portion 9. These protrusions are bent in opposite directions and fit into grooves 1) provided on the bottom surface of the frame section 9, forming the bottom surface of the frame section 9 into a flat surface.

After fitting the frame portion 9 into the capacitor body l, heat treatment is performed to heat and deform the upper end portion along the middle of the crimped portion of the capacitor, as shown in FIG. is fixed to the lower end of the capacitor body l.

According to this embodiment, the frame portion 9 is fixed to the lower end portion of the capacitor body 1 by thermal deformation, and the manufacturing process is simpler than when the entire capacitor element is molded. Further, since the temperature at which the frame portion 9 is thermally deformed is also lower than the molding temperature, the thermal influence on the internal capacitor element 2 is reduced.

In addition, since the frame portion 9 and the capacitor body l are firmly fixed due to thermal deformation of the frame portion 9, this is compared to the case where, for example, an insulating plate or the like is placed on the end face of the capacitor body and the lead wires are bent and fixed. This makes it possible to achieve a strong fixed state. Therefore, in the leadless electrolytic capacitor according to this embodiment, mechanical stress on the frame portion 9 is not applied to the internal capacitor element 2 through the lead wires 6 and 7.

〔Effect of the invention〕

As described above, the present invention provides a method for manufacturing a leadless electrolytic capacitor, in which at least one end face of the outer case and a part of the caulked part on the side surface of the outer case are attached to the end face side from which the lead wires are led out. The capacitor element is fitted with a frame that covers part or all of the capacitor, the frame is heat-treated to be anchored to the caulking part, and the lead wire led out from the capacitor element is bent along the outer bottom surface of the frame. A leadless electrolytic capacitor that can be mounted on a face bonding board can be easily manufactured without changing the structure of a normal electrolytic capacitor.

In addition, after the frame is fitted onto the capacitor body, it is heat-treated and deformed along the crimped part of the capacitor, ensuring a secure connection between the frame and the capacitor body, allowing leadless electrolytic capacitors to be attached to the board. It also becomes strong against mechanical stress when installed on a vehicle.

Also, compared to the conventional process of molding the entire capacitor element or part of the capacitor body,
There is no need for the process of injecting resin into a mold, etc., and a strong bond can be achieved just by heat treatment.

In summary, the present invention is an advantageous invention in which a leadless electrolytic capacitor that can be mounted on a face bonding board can be manufactured without changing the structure of a conventional electrolytic capacitor itself.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the completed state of a leadless electrolytic capacitor manufactured according to an embodiment of the present invention. FIG. 2 is a sectional view showing the structure of a conventional leadless electrolytic capacitor. FIG. 3 is a perspective view showing the shape of the frame used in the embodiment, and FIG. 4 is an explanatory diagram illustrating the process of manufacturing a leadless electrolytic capacitor according to the embodiment of the present invention. 1...Capacitor body, 2...Capacitor element, 3...
Electrode foil, 4. Electrolytic paper, 5. Exterior case, 6, 7.
15... Lead wire, 8... Sealing body, 9... Frame part, 13... Exterior member, 14... Lead part.

Claims (1)

[Claims] (1) Fitting a frame portion that covers at least one end surface of the outer case and a part or all of the caulking portion on the side surface of the outer case onto the end surface side from which the lead wire is led out;
A method for manufacturing a leadless electrolytic capacitor, in which the frame is anchored to the caulking part by heat treatment, and the lead wire led out from the capacitor element is bent along the outer bottom surface of the frame.