JPH0459767B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electronic component, and more specifically, to a leadless polarized electronic component that is surface-mounted on a printed circuit board or the like. In the following description, an aluminum electrolytic capacitor, which is a type of polar electronic component, will be explained in detail, but the present invention is not limited to aluminum electrolytic capacitors, and the same applies to other polar electronic components.

Conventional structure and problems thereof A conventional so-called leadless polar electronic component of this type, such as a chip-type aluminum electrolytic capacitor, is constructed as shown in FIG. That is, an anode foil formed by roughening aluminum foil and forming a dielectric oxide film by anodizing the surface, and a cathode foil formed by roughening aluminum foil are wound through a separator and impregnated with a driving electrolyte. This capacitor element is housed in a cylindrical metal case 2 with a bottom, and the open end is sealed with an elastic sealing material 3 such as rubber to form an aluminum electrolytic capacitor. Then, the lead wire 4 drawn out from the aluminum electrolytic capacitor is electrically and mechanically connected to the comb-shaped terminal 5 by a method such as welding, and a molded resin sheath 6 is applied to the whole except for the comb-shaped terminal 5. It was considered a finished product.

This type of chip-type aluminum electrolytic capacitor is
In order to provide solder heat resistance when mounting on a printed circuit board, a molded resin exterior 6 is applied as described above, but in general, the molded exterior is
Pressure is applied at a temperature of 100℃ to 150℃ for about 5 minutes at a pressure of 10Kg/ ^cm2 . Under such harsh conditions, the driving electrolyte of the electrolytic capacitor evaporates, causing a decrease in capacitance and This has resulted in deterioration of characteristics such as an increase in tan δ, and since it is coated with a molded resin, it is extremely expensive. Furthermore, since it is a horizontal type, when it is mounted on a printed circuit board, it occupies a large area of the printed circuit board, which is a factor that hinders miniaturization of various devices. Moreover, since it is symmetrical, the polarity cannot be easily determined visually, and the polarity display must be printed or engraved on the main body.

OBJECTS OF THE INVENTION The present invention eliminates these conventional drawbacks, and aims to provide a leadless polarized electronic component that does not suffer from characteristic deterioration, is inexpensive, and whose polarity can be easily determined.

Structure of the Invention To achieve this object, the present invention provides an electronic component that is surface-mounted on a printed circuit board, etc., in which a component element is housed in a cylindrical case with a bottom, and the open end of the case is sealed with a sealing member. an electronic component body configured by the above, and in which a lead wire connected to the component element is passed through a sealing member and drawn out from the same end surface; and a rectangular insulating plate having a through hole through which the lead wire passes and having a size larger than the case, and a recess connected to the through hole is separated from each other on an outer surface of the insulating plate that contacts a printed circuit board, etc. At the same time, the tip of the lead that has passed through the through hole is bent so that it is disposed in the recess, and the anode or cathode side is provided at the corner of the insulating plate that protrudes outward from the case. It is equipped with a polarity display section that displays the polarity.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 2 to 4 regarding an aluminum electrolytic capacitor. In addition, in the figure, the same parts as in FIG. 1 are given the same numbers.

In the figure, 1 is a capacitor element similar to the conventional one, consisting of an anode foil made of a high-purity aluminum foil electrochemically roughened and then anodized to form a dielectric oxide film, and a roughened cathode. wrapped around aluminum foil with insulating paper in between, and
It is constructed by impregnating the wound material with a driving electrolyte. This capacitor element 1 is housed in a cylindrical metal case 2 with a bottom. Further, a lead wire 4 is connected to the anode foil and the cathode foil of the capacitor element 1.

The open end of the metal case 2 is connected to an elastic body 7a.
and a non-elastic body 7b.
is inserted and sealed by drawing, thereby forming the electronic component body. Further, the lead wire 4 connected to the capacitor element 1 passes through the sealing member 7 and is drawn out from the same end surface.

Reference numeral 8 denotes a rectangular insulating plate larger than the metal case, which is arranged so as to come into contact with the end surface from which the lead wire 4 of the electronic component body is drawn out. A hole 8a is provided.

A chamfered portion 9 serving as a polarity display portion indicating the anode or cathode side is formed at a corner portion of the insulating plate 8 that protrudes outward from the metal case 2, and as a result, polarity discrimination becomes extremely easy. In order to form the polarity display portion on the insulating plate 8 in this manner, shapes as shown in FIGS. 4a to 4d may also be considered. That is, the one in FIG. 4a has arcuate chamfers 9 formed on two corners, and the one in FIG. 4b has arcuate chamfers on two corners of the square insulating plate 8. 9 and planar chamfered portions 9 on the other two corners.
The one shown in FIG. 4c has triangular protrusions 10 on the two corners of the rectangular insulating plate 8, and the one shown in FIG. Triangular projections 10 of different heights are provided at the remaining corners of the insulating plate 8.

Further, on the outer surface of the insulating plate 8 that comes into contact with a printed circuit board, etc., recesses 8b connected to the through holes 8a are provided in a separated state from each other, and the tips of the lead wires 4 passing through the through holes 8a are provided. The portion 4a is bent so as to fit within the recess 8b.

That is, a wall formed by a part of the insulating plate 8 exists between the recesses 8b, and an insulating wall is interposed between the tip portions 4a of the lead wires 4 passing through the insulating plate 8. When surface-mounting and soldering to a printed circuit board or the like, it is possible to prevent the solder from flowing between the lead wires 4 and causing the lead wires 4 to be shot.

As described above, according to the electronic component of the present invention, the polarity display section is provided at the corner of the insulating plate, and the shape is asymmetric between the anode side and the cathode side, so even after being mounted on a printed circuit board, Polarity can be easily determined visually from the top and side, eliminating erroneous operations during mounting. In particular, in the present invention, since the polarity display part is provided at the corner of the rectangular insulating plate, it is only necessary to have the insulating plate of the minimum required size compared to the case, and the overall size can be reduced. . Moreover, since no mold resin exterior is used, it is possible to produce polar electronic components at low cost without deterioration of characteristics.

In addition, there is a wall formed by a part of the insulating plate between the recesses, and as a result, an insulating wall is interposed between the tips of the lead wires that penetrate the insulating plate. When surface-mounted and soldered, it is possible to prevent solder from flowing between the lead wires and causing the lead wires to be shot.

Furthermore, in the present invention, the lead wire is passed through a through hole provided in the insulating plate and bent to form a terminal portion for connection with an external circuit, without being coated with molded resin. Even if the printed circuit board bends or warps after soldering, there will be some slack, or so-called "play", between the through hole in the insulating board and the lead wire, so defects such as cracks will not occur. It is also possible to obtain the effect that this does not occur.

[Brief explanation of drawings]

Figures 1a and b are cross-sectional views and side views of a conventional chip-type aluminum electrolytic capacitor, Figure 2 is a perspective view of a leadless aluminum electrolytic capacitor according to an embodiment of the present invention, and Figure 3 is a cross-sectional view of a conventional chip-type aluminum electrolytic capacitor. The half-cut sectional views and FIGS. 4a to 4e are perspective views showing other embodiments of the insulating plate. 1...Capacitor element, 2...Metal case, 4
... Lead wire, 7 ... Sealing member, 8 ... Insulating plate,
8a...through hole, 9...chamfer, 10...protrusion.

Claims (1)

[Claims] 1. In an electronic component that is surface mounted on a printed circuit board, etc., a lead wire that is constructed by housing a component element in a bottomed cylindrical case and sealing the open end of the case with a sealing member and connected to the component element. an electronic component body formed by penetrating a sealing member and drawing it out from the same end face, and a through hole through which the lead wire passes through and which is disposed so as to abut the end face of the electronic component body from which the lead wire is drawn out, and and a rectangular insulating plate larger in size than the case, the outer surface of the insulating plate that comes into contact with the printed circuit board etc. is provided with recesses connected to the through-holes separated from each other, and the recesses connected to the through-holes are separated from each other. The tip of the lead is bent so as to be disposed in the recess, and a polarity display section for indicating an anode or a cathode side is provided at a corner of the insulating plate protruding outward from the case. polarized electronic components.