JPS6135689B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing resin-encased metallized polypropylene film capacitors.

Generally, the manufacturing method for this type of capacitor is to store a capacitor element with lead terminals attached in a rectangular resin case prepared in advance, and fill the void in the case with epoxy resin as a filler to seal it. I have to. However, if the capacitor element is made of metallized polypropylene film, the specific gravity is lower than that of the epoxy resin used as the filler, so the capacitor element may float during the epoxy resin filling process, reducing the thickness of the epoxy resin at the case opening. This caused the problem that the capacitor element would stick out from the resin surface, impairing its moisture resistance. Therefore, conventionally, as a means to prevent capacitor elements from lifting up when filled with epoxy resin, a plurality of rectangular resin cases 1a, 1b, 1c, 1 are arranged side by side as shown in FIG.
Capacitor elements 3a, 3b, 3c, 3d, 3e... with lead terminals 2 attached to each of them d, 1e...
A method is used in which a stopper 4 is placed on the surface of the lead-out terminal 2, and an epoxy resin 5 is filled. However, the capacitor element 3a,
3b, 3c, 3d, 3e... Output terminal 2 to end face
It is difficult to maintain the mounting position in the height direction of the capacitor element 3a at a constant position, and if capacitor elements 3a,
Storage positions of 3b, 3c, 3d, 3e... vary, square resin cases 1a, 1b, 1c, 1d, 1
(e) If the thickness of the epoxy resin 5 at the opening varies and a sufficient thickness cannot be ensured, it causes poor moisture resistance and has the disadvantage of not being able to withstand long-term use. Therefore, it would be possible to press each terminal one by one and fill it with epoxy resin, but this could not be considered an effective method as it had problems with workability and went against the recent trend of automation.

The present invention was made in view of the above points, and the capacitor element is adhered to the inside of the resin case using double-sided adhesive tape before filling with epoxy resin, thereby preventing the capacitor element from lifting during the epoxy resin filling process, improving workability and providing moisture resistance. It is an object of the present invention to provide a method for manufacturing metallized polypropylene film capacitors without the risk of defects.

An embodiment of the present invention will be described below with reference to the drawings. That is, as shown in FIG. 2, a plurality of capacitor elements 11 each formed by winding a metallized polypropylene film capacitor are tightened together to the optimum dimensions using a fastener 12, and in this state, they are heat-treated at 80 to 90°C for about 1 hour. I do. Next, capacitor element 1
Solder or zinc metal powder is thermally sprayed onto one end surface to form a metallicon electrode 13, and a lead terminal 14 is attached to the metallicon electrode 13. Then the fastener 12
As shown in FIG. 3, a double-sided adhesive tape 15 is pasted on the side opposite to the lead-out side of the lead-out terminal 14 of each separated capacitor element 11. As shown in FIG. 4, the capacitor element 11 is housed in a square resin case 16 made of polyester, polycarbonate, vinyl chloride, ABS resin, etc., and the capacitor element 11 is placed in the inner bottom of the square resin case 16. The epoxy resin 17 is then adhesively fixed with double-sided adhesive tape 15, and then the void in the square resin case 16 is filled with epoxy resin 17, and the epoxy resin 17 is cured by heat.
By using the above-mentioned means, the capacitor element 11
Double-sided adhesive tape 15 on the inner bottom of the square resin case 16
Since the capacitor element 11 can be reliably bonded and fixed by using metallized polypropylene film, even if the specific gravity is lower than the epoxy resin 17 used as a filler, the capacitor element 11 will not be lifted up during the filling process of the epoxy resin 17, and the initial The set opening thickness t of the epoxy resin 17 can be ensured. Therefore, the problem of poor moisture resistance due to insufficient opening thickness t can be solved, and at the same time, opening thickness t can be set to the minimum necessary, contributing to miniaturization. Furthermore, by simply storing the capacitor element 11 in the square resin case 16, the epoxy resin 17 can be fixed with adhesive, and a fixed storage position can be secured without using any special means.
It has many advantages such as easy automation including filling. In the above example, double-sided adhesive tape 1
5 has been described in which the capacitor elements 11 are removed from the fastener 12 and separated individually, but as shown in FIG. If the double-sided adhesive tape 20 is attached in this state, the double-sided adhesive tape 20 is cut into each capacitor element 18, and then the fastener 19 is removed to separate the capacitor elements 18 individually, the work efficiency can be greatly improved. can. 21 is a metallic electrode,
22 is a lead terminal. Next, FIG. 6 shows a comparison of characteristics between the metallized polypropylene film capacitor A obtained by the present invention and the metalized polypropylene film capacitor B obtained by the conventional means (the means explained based on FIG. 1). 〜Explained with reference to FIG. Both A and B were capacitor elements with a rating of 250V.AC-2μF made by polymerizing and winding polypropylene films metallized on one side, and the samples were each set to n=50. In other words, Figures 6 to 8 show the tanδ capacitance change rate and insulation resistance characteristics with respect to the standing time when 50 samples each were left in a constant temperature and humidity chamber at a temperature of 40°C and a humidity of 90 to 95%. . The measurement temperature was 20°C. As is clear from FIGS. 6 to 8, capacitor B manufactured using the conventional method shows that variations in all of the characteristics of tan δ, capacitance change rate, and insulation resistance become larger over time, and the characteristics deteriorate more severely. On the other hand, capacitor A according to the present invention has small variations in all of the above-mentioned characteristics, indicating that stable characteristics can be maintained for a long period of time.

As described above, according to the present invention, when manufacturing a metallized polypropylene film capacitor encased in a resin case, a plurality of capacitor elements are fixed with a fastener, a metallicon electrode is formed on the end face of the element, and a lead terminal is attached to the electrode. After applying double-sided adhesive tape to the side opposite to the lead-out side of the lead-out terminal, the capacitor element is housed in a resin case, fixed in the case with adhesive tape, and filled with epoxy resin. A manufacturing method for metallized polypropylene film capacitors that has great practical value and facilitates automation, which enables the production of capacitors that have excellent moisture resistance and can contribute to miniaturization without deterioration of characteristics even after long-term use. can be obtained.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the manufacturing process of a metallized polypropylene film capacitor by a conventional method.
Figures 2 and 5 relate to one embodiment of the present invention; Figure 2 is a perspective view showing a part of the manufacturing process of a metallized polypropylene film capacitor, and Figure 3 is a perspective view showing a capacitor element before being housed in a resin case. Figure, 4th
The figure is a sectional view showing a metallized polypropylene film capacitor, FIG. 5 is a perspective view showing a part of the manufacturing process according to another embodiment of the metallized polypropylene film capacitor, and FIGS. Figure 6 shows a comparison of the characteristics of metallized polypropylene film capacitors obtained by this method in a humidity storage test.
FIG. 7 is a capacitance change rate curve diagram, and FIG. 8 is an insulation resistance characteristic curve diagram. 11, 18... Capacitor element, 12, 19...
... Fastener, 13, 21 ... Metallicon electrode, 1
4, 22... Output terminal, 15, 20... Double-sided adhesive tape, 16... Square resin case, 17... Epoxy resin.

Claims (1)

[Scope of Claims] 1. Means for flattening a plurality of metallized polypropylene film capacitor elements with a fastener;
means for forming metal contact electrodes on both end faces of the capacitor element and attaching external terminals; means for pasting double-sided adhesive tape on the side surface of the capacitor element facing the external terminal lead-out side; A means for adhesively fixing it within the case;
A method for manufacturing a metallized polypropylene film capacitor, comprising means for filling the case cavity with an epoxy resin. 2. means for flattening a plurality of metallized polypropylene film capacitor elements with a fastener;
means for forming metal contact electrodes on both end faces of the capacitor element and attaching external terminals; means for pasting double-sided adhesive tape on the side surface of the capacitor element facing the external terminal lead-out side while being tightened with the fastener; means for cutting the tape into individual capacitor elements and removing the fasteners to separate the capacitor elements into individual capacitor elements; and after the means, storing the individually separated capacitor elements in a resin case and placing them in the case using the tape; A method for manufacturing a metallized polypropylene film capacitor, comprising means for adhesively fixing the capacitor and means for filling the cavity in the case with an epoxy resin.