JPS6012281Y2 - Electrolytic capacitor - Google Patents

Description

[Detailed description of the invention] This invention relates to electrolytic capacitors, and in particular aims to reduce the cost of large-capacity electrolytic capacitors used in high-voltage circuits and reduce the area occupied on the mounting board. .

Conventionally, electrode foils used in large-capacity electrolytic capacitors for high-voltage circuits have fine pores that are roughened by electrolytic etching because the thickness of the anodic oxide film, which is the dielectric, increases in proportion to the anodic oxidation voltage. is filled with an anodic oxide film.

Therefore, as the anodic oxidation voltage increases, the capacitance decreases exponentially.

Furthermore, as the thickness of the anodized film increases, the physical strength of the foil also decreases.

For this reason, it has become necessary to use a thick foil having a thickness of 1100 P or more for the raw foil used as the electrode foil.

Therefore, the product size becomes extremely large, and as a result, the unit cost of the exterior case and sealing plate becomes expensive, which has the disadvantage of increasing the product cost.

The present invention standardizes the above-mentioned high-voltage, large-capacity products to reduce manufacturing costs, and also connects the products themselves in series to reduce the area occupied by the mounting board.

The present invention will be described below with reference to embodiments shown in FIGS. 1 and 2.

FIG. 1 is a sectional view of an electrolytic capacitor, in which a wound capacitor element 1 is housed in an exterior case 3 after impregnating an electrolytic solution into the capacitor element 1 having lead-out leads 2 and 2' for connecting external terminals.

The exterior case 3 has a recessed portion on the outer surface of the bottom portion, and a cylindrical terminal 4 made of solderable metal is previously attached to the inner wall of the recessed portion.

After the one-side glued 2 and the cylindrical terminal 4 are connected by a rivet 6 or the like, the recess is filled with a low melting point metal 5 such as solder.

The other counter electrode lead 2' is connected to an external lead terminal 8 whose tip end 7 has a convex shape and size that can be bonded and soldered to the recess of the exterior case 3.

After capacitor element 1 is housed in case 3 in this manner, sealing plate 9 is fitted into the opening of case 3, and sealing resin 10 is then filled and sealed.

The product manufactured according to the above embodiment has concave and convex terminals at both upper and lower ends of the exterior case 3.

Incidentally, in the above embodiment, a screw groove may be provided on the side surface of the recess or on the external terminal so that two capacitors can be connected in series with a screw.

FIG. 2 shows an example of the use of the electrolytic capacitor according to the present invention. For example, two capacitors are connected in series and the operating voltage is twice the rated voltage of each capacitor.

The convex tip 7 of the terminal 8 is inserted into a hole previously provided in the mounting board 13 and fixed with solder 12 or the like.

Further, the solder 5 in the recess provided on the bottom surface of the exterior case 3 is melted, and the convex tip 7 of the terminal 8 of another capacitor is inserted into this molten solder and connected.

Then, by soldering and connecting the solder 5 in the recess provided on the bottom of the external case 3 of the other stacked capacitor to the electrode 14 on the board 13 using the lead wire 11, the two products are connected. This is a series connection.

Due to the characteristics of capacitors, when n capacitors are connected in series, their capacitance decreases to 1.

Therefore, when using n devices connected in series, a withstand voltage of 1 and a capacitance of n times the rated value are required.

For example, for a rating of 500W V -2200μF,
Five 100WV-11000μF are required.

The electrode foil used as a standard specification has an anodizing voltage of 540V for 500WV and 125V for 1100WV.
At 540V, the thickness of the document used as V tossle and electrode foil needs to be 100μm, but at 125V it needs to be 6μm thick.
The thickness may be 5 to 70 μm.

Moreover, although there are differences in surface roughening methods, the capacitance of 125V foil is about m times that of 540V foil.

Therefore, when using five devices connected in series as described above,
Even if 5 times the product capacity is required, the required anode foil area will be approximately the same.

As a result, the amount of the anode foil used was significantly reduced, as well as the amount of the cathode foil, separator, etc., making it possible to significantly reduce material consumption.

As shown above, the electrolytic capacitor of the present invention has a simple structure for series connection, occupies less installation space for stacking and connecting capacitors, and significantly reduces the amount of materials used.
It has great industrial and practical value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the electrolytic capacitor of the present invention.
FIG. 2 is a front view of two electrolytic capacitors connected in series and mounted on a printed circuit board. 1: capacitor element, 2, 2': drawer lead, 3: exterior case, 5: solder reservoir, 8: external terminal, 9: sealing plate.

Claims (1)

[Scope of utility model registration request] The bottom of the bottomed exterior case has a recess with a diameter that fits the external terminal, and the sealing plate that fits into the opening of the case has the external terminal formed, and the recess or external terminal and the capacitor are connected to each other. An electrolytic capacitor made by connecting the lead leads drawn out from the element.