JPH0332907B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chip-type film capacitor obtained from a film capacitor element equipped with lead wires, and a method for manufacturing the same. Chip-type film capacitors were made only by bending wires, and this satisfied the demand for miniaturization of conventional film capacitors.
The present invention discloses that the film capacitor can be made into a chip as it is and can be used as a film capacitor with sufficient reliability like other chip-shaped parts.

In recent years, electronic components have become increasingly lighter, thinner, shorter and smaller due to high-density mounting on printed wiring boards. In order to meet this demand for miniaturization and increase packaging density, a large number of rectangular or cylindrical components without lead wires, so-called leadless types, are being used.

Chip-type mounting electrodes generally do not use lead wires, but use metal caps or terminal plates as electrodes, or metal electrodes are provided by applying conductive paint or metal spraying, etc., and these are printed. It is placed between the lands of a wiring board with an adhesive, etc., and attached by soldering using the solder dip method or reflow method. However, since the structure and manufacturing method are different from those with lead wires, the lead type There are some points that make it difficult to standardize with the existing ones.

On the other hand, electronic components equipped with lead wires are also rapidly being developed to become more compact, and are often used in combination with the above-mentioned chip-shaped components. However, due to manufacturing issues, mass production is difficult. is the current situation.

As described above, the present invention provides a chip-type film capacitor which can be made into a chip electrode simply by bending the lead wires of a conventional flat-type film capacitor having lead wires in the same direction and bringing them into close contact with the surface of the main body.

Traditionally used film capacitors consist of (1) a pair of films and a pair of electrode foils that are wound alternately, and in the middle of the winding, the lead wires are fixed to the electrode foils by welding or other methods. Something with a flat shape. (2) After winding a pair of films and a pair of electrode foils alternately so that the electrode foils protrude to opposite sides in the width direction, and forming a flat shape,
Lead wires are firmly attached by welding to the protruding parts of the electrode foil on both sides. (3) Also, a pair of single-sided metalized films or a double-sided metalized film and a film are rolled together so that electrodes can be formed on both sides, flattened, and then metal sprayed on both sides to form electrodes. There are types with lead wires coming out from both ends, and types that are laminated, each coated with resin.

The present invention can be applied to any type of film capacitor in which the above flat lead wires are led out in the same direction. That is, the above film capacitor elements are all flat,
The lead wire is bent in the drawing direction along the element, into one surface or from one surface to the back surface, and is brought into close contact with the element surface, and the whole is covered with resin and a part of the lead wire on one or both sides is bent. The electrode is made to protrude, so the soldered electrode is in close contact with the main body.

The chip capacitor of the present invention can be made suitable for mass production as described below.

Next, the manufacturing method will be described.

A large number of wound lead wires of a flat or laminated element are held on a plate-shaped jig or a mount almost perpendicularly to the length direction with adhesive tape at regular intervals. In this state, hold the head or lead wire of each element against the plate-shaped jig or mount, and run it on the element surface along the lead wire direction.
After bending the lead wire so that it is wound within half a turn or within one turn, one element at a time, or at the same time, the lead wire is impregnated with a resin, dried and hardened, or coated with either one of them. After aging, at least one part of the lead wire on one surface, which will become the electrode, is ground to expose it so as to protrude, and the remaining lead wire is cut off. When cut, the chip-shaped film capacitors become individual pieces, but in mass production equipment, they can be placed side by side on a tape carrier at regular intervals and connected to the next process.

As mentioned above, the electrodes can be provided on one side, or on one or both sides, depending on whether the lead wire is bent less than half a turn or less than one turn. When bending within one turn, whether to provide electrodes on one side or both sides can be arbitrarily determined based on design.

Generally, the tip of the lead wire is flattened to maintain sufficient strength for welding, etc., but in the case of the present invention, the lead wire is not only the welded part but also the part that will become the chip electrode. A flat shape allows it to sit better on the surface of the capacitor.
Therefore, in the present invention, it is desirable that part or all of the lead wire be made into a flat shape in order to improve the adhesion as well as the stability of the attachment to the printed wiring board.

Next, the diagram will be explained.

FIG. 1 shows a capacitor element, in which 1 is a flat body, and 2 is a lead wire drawn out in the same direction.
A is a top view, b is a front view, and c is a side view.

FIG. 2 shows the capacitor element bent within one surface in the direction in which the lead wires are pulled out, with a being a top view and b being a front view. FIG. 3 shows the lead wire bent from the first surface into the back surface, and a is a top view and b is a front view. Figures 4 and 5 show chip-type film capacitors of the present invention, in which the elements shown in Figures 2 and 3 are impregnated and/or coated with resin. After the resin is cured, a portion of the lead wire that will become the electrode is exposed by grinding, and the remaining lead wire is cut to obtain a solder electrode. Figure 4 shows a chip capacitor 4 with soldered electrodes exposed on only one surface.
is a top view, and b is a front view. FIG. 5 shows a chip-type capacitor 5 in which the lead wires are bent from the first surface to the inside of the back surface, and electrodes are exposed on both sides, and a is a top view and b is a front view. In the case of FIG. 5, the electrodes may be exposed only on one surface and the other surfaces may be left covered with resin. You can choose one based on the usage of the parts. FIG. 6 is a diagram showing a so-called taped state in which elements are clamped at regular intervals with adhesive tape 7 on a plate-shaped jig 6, and a is a front view and b is a side view. 7 and 8 show the process of the manufacturing method of the present invention. In FIG. 6, the head part of the element or the lead wire portion,
Alternatively, it shows a state in which both are held down and the lead wires are bent in the lead-out direction so as to touch the surface of the element 1, and this may be done one by one sequentially or simultaneously in manufacturing. The same thing can be done even if the lead wire is in contact with the surface opposite to that shown in FIG. FIG. 7a is a front view, and FIG. 7b is a side view. Figure 8 shows a case in which the lead wire is wound once as opposed to half a turn in Figure 7. In this case, the lead wire is wound half more than in Figure 7, and therefore the lead wire is wrapped around both sides of the element. This will bring them closer together. Figure 8a
is a front view, and b is a side view. Figure 9 shows the 8th
As an example of resin impregnation or coating with each jig in the figure, an example of dipping the liquid resin 11 placed in the resin tank 10 is shown. It may be coated with any resin such as dipping, powder coating or the like. As will be described later, since a thermosetting resin is generally used, a curing step is required, but this is omitted in the figure. Although FIG. 9 shows the case of resin coating the device shown in FIG. 8 with electrodes attached on both sides, the same applies to the case where the device shown in FIG. 7 with electrodes attached on one side is coated. FIG. 10 is an explanatory diagram showing an element 12 coated with resin, and only one element is shown. FIG. 11 shows a capacitor 12 of the present invention in which the resin-coated surface is ground (not shown) to expose the lead wires that will become the electrodes. Cut to specified length. By cutting, the chip-shaped film capacitors are separated into individual pieces, but as described above, they can be freely arranged one after another at regular intervals on a carrier tape or the like and connected to the next process. Figure 12 shows a film capacitor element with lead wires held at regular intervals on a mount with adhesive tape at almost right angles to the length direction.
In addition to the method using the plate-shaped jig shown in the figure, the present invention can also be carried out in a state in which the jig is taped to a mount as shown in FIG. The method is the same as that for taping a plate-shaped jig, so the explanation will be omitted.
14 is a feed hole of the mount. 13 is a front view (a) and a side view (b) showing a state in which the chip-type film capacitor 4 of the present invention shown in FIG. 4 is attached to a printed wiring board 15. FIG. (The figure has been enlarged) For soldering, apply adhesive 17 between the wiring board lands, apply solder paste to the mounting part of the land and pass it through a reflow oven, or apply adhesive 17 and solder dip. This is done by passing it through a tank. In this case, it is necessary to use a film with high heat resistance. Further, in the case of using a reflow oven, application of adhesive can be omitted. Although FIG. 13 shows a case where a chip-type film capacitor is attached to a printed wiring board, the same applies to the case where a chip-type film capacitor 5 shown in FIG. 5 is attached.

From FIG. 13, it can be seen that the chip-type film capacitor of the present invention is conventionally used in the height direction.
It is used in the thickness direction.

In the above explanation, the manufacturing method of the present invention has been described in which an element without resin impregnation or exterior coating is held on a plate-shaped jig or mount with adhesive tape. Alternatively, a chip-type film capacitor can be manufactured by directly bringing lead wires into close contact with the surface of an element coated with one of the elements.

Regarding materials, electrode foils are usually made of
Aluminum etc. are used. The film may be of any material that can be used as a film capacitor, such as polyethylene terephthalate, polycarbonate, polypropylene, or a combination thereof. However, for the present invention to be miniaturized, that is, to be made into chips, it is desirable to select a material with good heat resistance. Polyethylene terelate film, which is the most commonly used film, is also suitable. Epoxy resin is most often used as the exterior resin, but you can freely choose one that is heat resistant and has little heat deformability. As for the coating method, you can freely select and use any applicable methods such as molding, liquid coating, liquid coating, powder resin, and the use or combination of other UV-curing resins and electron beam-curing resins. can.

The lead wire may be any wire used in a film capacitor, such as a copper-clad steel core wire, a solder-plated annealed copper wire, or a tin-plated wire. Although the wire diameter is not particularly limited, wires as thin as 0.5 to 0.3 mm or less are usually used, and there are no particular problems with bending.

To summarize the features of the present invention as described above, the present invention discloses a chip-type film capacitor that makes a conventional film capacitor having a lead wire smaller and forms a chip electrode using the lead wire, and a method for manufacturing the same. Since the conventional type with lead wire can be used as a chip type, it is desirable from the point of view of standardization, and is also effective in terms of manufacturing control, which leads to lower product costs. This invention is based on a technical idea that breaks away from the image that it has a structure different from the conventional one with lines, and is industrially useful.

[Brief explanation of drawings]

Fig. 1 shows a film capacitor element with lead wires, Fig. 2 shows a chip-type film capacitor element according to the present invention having electrodes on one surface, and Fig. 3 shows a chip-type film capacitor element according to the present invention having electrodes on both surfaces. shows. Figures 4 and 5 are
These are examples of chip-type film capacitors of the present invention. Figure 6 shows a film capacitor element taped to a plate-shaped jig. 7 to 11 show a method of manufacturing a chip-type film capacitor. FIG. 12 shows a film capacitor element taped on a mount with adhesive tape, a is a front view and b is a side view, and the manufacturing method is similar to that shown in FIGS. 7 to 11. Figure 13 shows the chip-type film capacitor of the present invention mounted on a printed wiring board by soldering, where a is a front view;
b is a side view. DESCRIPTION OF SYMBOLS 1... Film capacitor element, 2... Lead wire, 3... Resin coating layer, 4... Chip-type film capacitor according to the present invention, 5... Chip-type film capacitor according to the present invention, 6... Plate-shaped jig. , 7... Adhesive tape, 8... Element wrapped around lead wire and bent, 9... Element wrapped around lead wire and bent, 10... Resin tank, 11... Resin, 12
... Capacitor of the present invention under manufacture, 13 ... Cutting blade, 14 ... Feed round hole, 15 ... Printed wiring board, 1
6... Conductor portion (land) of printed wiring board, 17...
...Adhesive, 18...Soldered state, 19...Exposed electrode.

Claims (1)

[Claims] 1. A flat type lead in the same direction formed by winding an electrode foil such as aluminum and a dielectric material such as a plastic film, or winding or laminating two single-sided metalized films or two double-sided metalized films together. In a capacitor group in which a capacitor element is placed on a plate-shaped jig or mount, and the lead wires of the elements are sandwiched with adhesive tape at regular intervals along the length of the capacitor element, semi-circular strips are placed on the element surface along the direction in which the lead wires are drawn out. A chip shape is obtained by wrapping the lead wire within 1 turn or less, wrapping it with resin, then grinding it to expose the lead wire electrode protruding from at least one surface, and cutting off the remaining lead wire. Method of manufacturing film capacitors. 2. The method of manufacturing a chip-type film capacitor according to claim 1, wherein lead wire electrodes are exposed on the surface of the capacitor. 3. A flat film capacitor element with leads in the same direction, which is made by winding an electrode foil such as aluminum and a dielectric material such as a plastic film, or by winding or laminating two films metalized on one side or a metalized film on both sides. In a group of capacitor elements in which the lead wires of the above-mentioned elements are held on a board jig or a mount at regular intervals with adhesive tape or the like at regular intervals, approximately perpendicular to the length direction of the capacitor elements, A method for manufacturing a chip-shaped film capacitor, characterized in that a lead wire is wound within half a turn or within one turn along the same line and then folded one by one sequentially or simultaneously. 4. The method for manufacturing a chip-shaped film capacitor according to claim 3, wherein the capacitor element is neither impregnated with resin nor coated. 5. The method for manufacturing a chip-shaped film capacitor according to claim 3, wherein the capacitor element is impregnated with a resin or coated with a resin, or both. 6 In a group of capacitor elements in which flat capacitor elements with leads in the same direction are held approximately perpendicular to the length direction of a plate-shaped jig or mount using adhesive tape, etc., each capacitor element is At the same time, impregnate and coat with resin, or either one of them, and then grind after curing.
A method for manufacturing a chip-type film capacitor, in which an electrode is exposed so as to protrude on at least one surface, and the remaining lead wires are cut off. 7. A method for manufacturing a chip-type film capacitor according to claims 1 and 6, characterized in that a group of chip-type film capacitors formed by cutting lead wires are arranged on a carrier tape.