JPH0315330B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a leadless aluminum electrolytic capacitor.

Structure of conventional examples and their problems Conventional so-called leadless electronic components of this type, such as chip-type aluminum electrolytic capacitors, are the first
It was configured as shown in the figure. In other words, an anode foil made by roughening aluminum foil and forming a dielectric oxide film by anodizing, and a cathode foil made by roughening aluminum foil are wound through a separator and impregnated with a driving electrolyte. This capacitor element is housed in a bottomed cylindrical metal case (not shown), and the open end is covered with an elastic sealing material such as rubber (not shown). An aluminum electrolytic capacitor is constructed by sealing the aluminum electrolytic capacitor, and a lead wire (not shown) drawn out from the aluminum electrolytic capacitor is electrically and mechanically connected to the comb electrode 1 by a method such as welding. Furthermore, a molded resin sheath 2 was applied to the entire body except for the comb electrode 1, and the tip portion 1a of the comb electrode 1 was bent along the bottom surface of the molded resin sheath 2 to obtain a completed product.

However, in such a chip-type aluminum electrolytic capacitor, when the chip-type aluminum electrolytic capacitor is mounted on a printed circuit board and the tip portion 1a of the comb electrode 1 is soldered to the land portion of the printed circuit board by reflow soldering, the comb Since the thickness of the tip portion 1a of the electrode 1 is extremely thin, flux gas cannot be sufficiently removed during reflow soldering, resulting in poor soldering, so-called tunnel soldering.

Soldering defects can be corrected by reflowing again or using a soldering iron, but with chip-type aluminum electrolytic capacitors, as is clear from the above structure, the capacitor element is impregnated with driving electrolyte. , and because the sealing is performed using a sealing material or a molded resin exterior 2, there is not much margin for heat stress, and if heat is applied twice or thrice, problems will occur in the characteristics, so once the It was necessary to perform perfect soldering.

Purpose of the Invention The purpose of the present invention is to solve these conventional problems, and to provide an aluminum electrolytic capacitor that allows stable soldering by ensuring flux degassing during reflow soldering. It is something to do.

Structure of the Invention In order to achieve the above object, the aluminum electrolytic capacitor of the present invention includes a capacitor element in which an anode foil and a cathode foil are wound with a separator in between, and a driving electrolyte is impregnated therein, and the capacitor element is housed therein. a cylindrical case with a bottom, a sealing member housed in the opening of the case, through which the lead wire connected to the capacitor element is passed through in order to draw it out to the outside, and a sealing member housed in the opening of the case; an insulating plate disposed so as to be in contact with the insulating plate, a recess is provided on the outer surface of the insulating plate, and the tip of the lead wire to be connected to the printed circuit board by reflow soldering is bent into the recess. and a convex portion is formed on the outer surface of the insulating plate, the convex portion being located on both sides of the concave portion and abutting the printed circuit board to form a gap between the printed circuit board and the tip of the lead wire. It is something.

According to this configuration, when the aluminum electrolytic capacitor is mounted on the printed circuit board, the outer surface of the insulating plate has
Since the convex portions formed on both sides of the concave portion come into contact with the printed circuit board, the aluminum electrolytic capacitor can be mounted on the printed circuit board in a stable manner. When connecting the tip of the lead wire to the land of the printed circuit board by reflow soldering, the flux gas generated during reflow soldering will surely escape through the gap. As a result, defects such as tunnel solder can be reliably prevented with a simple configuration of just providing a convex portion that contacts the printed circuit board.

Embodiment Hereinafter, an embodiment of the present invention will be described based on FIGS. 2 to 4. In the figure, 11 is an anode foil formed by roughening an aluminum foil and further forming a dielectric film by anodizing, and a cathode foil formed by roughening an aluminum foil, which are wound through a separator, and are then wrapped around a drive electrolyte. This capacitor element 11 is constructed by impregnating it with a liquid, and is housed in a cylindrical metal case 12 with a bottom, and a sealing member 13 having elasticity such as rubber is housed in the opening of the metal case 12. We are sealing the door.
Further, this sealing member 13 is connected to the capacitor element 11.
The lead wire 14 is passed through in order to draw out the lead wire 14 connected to the outside. Reference numeral 15 denotes an insulating plate disposed so as to be in contact with the end surface of the opening of the metal case 12. This insulating plate 15 is provided with a through hole (not shown) through which the lead wire 14 passes, and furthermore, the outer surface of the insulating plate 15 is provided with a through hole (not shown) through which the lead wire 14 passes. is provided with a recess 16 that communicates with the through hole. The lead wire 14 is connected to an insulating plate 15.
through the through hole provided in the
A is processed into a flat shape, and further bent along the recess 16 to be housed in the recess 16. 1
7 is a round convex portion integrally formed on the outer surface of the insulating plate 15, located on both sides of the concave portion 16;
The convex portion 17 comes into contact with the printed circuit board when the chip-type aluminum electrolytic capacitor is mounted on the printed circuit board, and forms a gap between the printed circuit board and the tip 14a of the lead wire 14.

As mentioned above, in one embodiment of the present invention,
Since convex portions 17 are formed on the outer surface of the insulating plate 15 on both sides of the concave portion 16, when the chip-type aluminum electrolytic capacitor is mounted on a printed circuit board, the chip-type aluminum electrolytic capacitor is mounted in a stable state. Furthermore, since the convex portion 17 comes into contact with the printed circuit board, a gap is formed between the printed circuit board and the tip 14a of the lead wire 14, so that the tip 14a of the lead wire 14 is connected to the land of the printed circuit board. When connecting by reflow soldering to
The flux gas generated during this reflow soldering will surely escape through the gap. This eliminates defects such as tunnel soldering and enables stable soldering.

FIG. 5 shows another embodiment of the present invention,
In this embodiment, rectangular protrusions 17a are integrally formed on the outer surface of the insulating plate 15, located on both sides of the recess 16. This embodiment also provides the same effects as the above-mentioned embodiment.

Effects of the Invention As described above, the aluminum electrolytic capacitor of the present invention is arranged so as to be in contact with the end face of the opening of the case, has a recess on the outer surface of the insulating plate, and reflow solders the printed circuit board in the recess. The tips of the lead wires to be connected are bent and housed, and the tips of the lead wires are placed on the outer surface of the insulating plate so as to be in contact with the printed circuit board on both sides of the recess, so that the tips of the lead wires and the printed circuit board are connected to each other. Since the convex part is formed to form a gap between Because a gap is formed, when the tip of the lead wire is connected to the land of the printed circuit board by reflow soldering, the flux gas generated during this reflow soldering will surely escape through the gap, and as a result, the printed circuit board will be damaged. The simple structure of just providing a convex portion that comes into contact with the substrate can reliably prevent defects such as tunnel soldering.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a chip-type aluminum electrolytic capacitor showing a conventional example, FIG. 2 is a sectional view of a chip-type aluminum electrolytic capacitor showing an embodiment of the present invention, and FIG.
4 is a bottom view of the insulating plate in the electrolytic capacitor, and FIG. 5 is a bottom view of the insulating plate showing another embodiment of the present invention. 11... Capacitor element, 12... Metal case, 13... Sealing member, 14... Lead wire, 14
a...Tip of lead wire, 15...Insulating plate, 16
...Concave portion, 17...Convex portion.

Claims (1)

[Claims] 1. A capacitor element in which an anode foil and a cathode foil are wound with a separator in between and impregnated with a driving electrolyte, a cylindrical case with a bottom that houses this capacitor element, and a lead wire connected to the capacitor element. The lead wire is passed through the case in order to draw it out to the outside, a sealing member is housed in the opening of the case, and an insulating plate is disposed so as to come into contact with the end surface of the opening of the case, A recess is provided on the outer surface of the board, and the tip of the lead wire to be connected to the printed circuit board by reflow soldering is bent and stored in the recess, and a recess is provided on the outer surface of the insulating board. An aluminum electrolytic capacitor characterized in that convex portions are formed on both sides of the printed circuit board to abut on the printed circuit board and form a gap between the printed circuit board and the tip of the lead wire.