JPH0655232U - Electrolytic capacitor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an electrolytic capacitor in which air is not trapped in the space formed between the sealing portion side of the electrolytic capacitor and the substrate without lowering the sealing strength of the electrolytic capacitor. . An electrolytic capacitor in which a sleeve (insulating sleeve 4) is covered on the surface of an outer case (2), the space formed between the sealing portion side of the outer case and the substrate (12) surface in the sleeve. A cutout portion (22) for discharging air trapped in the portion (10) is formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an electrolytic capacitor in which the outer peripheral surface of an outer case is covered with an insulating sleeve.

[0002]

[Prior art]

 Generally, in an electrolytic capacitor, an outer sleeve is covered with an insulating sleeve, and this insulating sleeve is used as an indicator of the rating and the like together with the insulation of the outer case. Usually, a shrink sleeve made of synthetic resin having excellent heat shrinkability in terms of workability is used for this insulating sleeve.

For example, as shown in FIG. 3, when the outer case 2 is covered with a heat-shrinkable insulating sleeve 4 to be shrunk, the opening edge portion of the insulating sleeve 4 has a sealing body 6 for sealing the outer case 2. The upper surface is contracted and curved along the opening edge of the outer case 2 to form a space 10 on the sealing portion side together with the edge 8 of the outer case 2. This space portion 10 is more prominent and has a large volume when the edge portion 8 of the exterior case 2 is curled.

[0004]

[Problems to be solved by the device]

 By the way, the sealing portion side of such an electrolytic capacitor is applied to the mounting surface of the substrate 12, the lead 14 is inserted into the through hole 16 formed in the substrate 12 and temporarily fixed, and the conductive pattern 18 on the back surface side thereof is formed. The lead 14 is fixed and electrically connected with the solder 20. In this case, the mounting surface of the substrate 12 is covered with the insulating sleeve 4 that uniformly covers the sealing portion side of the outer case 2, and since the insulating sleeve 4 has an appropriate elasticity, the space 10 is hermetically sealed. It becomes a state. If the solder 20 is processed by solder reflow in this state, the air in the space 10 is warmed and expanded through the substrate 12, and is discharged from the space 10. Moreover, since the air in the space 10 is heated instantaneously, the expansion coefficient of the air is high, and the size is such that the electrolytic capacitor is pushed up. Therefore, when the solder 20 is connected and fixed, a tilt of the electrolytic capacitor and a so-called blow hole in which air passes through the solder 20 occur, which causes the reliability of the circuit device to deteriorate.

Conventionally, it has been proposed that a curling portion of an outer case is provided with a cutout portion to discharge air remaining in a space portion on a sealing side. However, in an electrolytic capacitor, airtightness determines a characteristic. Therefore, cutting off a part of the curling part of the outer case reduces the sealing strength by that amount and causes deterioration of the characteristics.

Therefore, the present invention provides an electrolytic capacitor in which air is not trapped in the space formed between the substrate side and the sealing side of the electrolytic capacitor without lowering the sealing strength of the electrolytic capacitor. The purpose is to do.

[0007]

[Means for Solving the Problems]

 As shown in FIG. 1, the electrolytic capacitor of the present invention is an electrolytic capacitor in which a sleeve (insulating sleeve 4) is covered on the surface of an outer case (2), and the sleeve has a sealing portion side and a substrate. It is characterized in that a notch (22) for discharging air trapped in a space (10) formed between the (12) plane and the (12) plane is formed.

[0008]

[Action]

 The space formed between the board on which the electrolytic capacitor is mounted and the sealing part communicates with the outside air through the notch formed in the sleeve, and the air expanded during soldering has the notch. It is released to the outside air. Therefore, it is possible to prevent the electrolytic capacitor from being pushed up due to the expansion of air and the generation of blow holes in the solder.

[0009]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of the electrolytic capacitor of the present invention. The electrolytic capacitor is sealed by an outer case 2 and a sealing body 6, and an outer surface of the outer case 2 is covered with an insulating sleeve 4. As the insulating sleeve 4, a shrink sleeve made of synthetic resin having heat shrinkability is used.

A pair of rectangular notches 22 are formed in the diametrical direction on the upper surface of the sealing body 6 of the insulating sleeve 4, that is, at the edge portion facing the sealing portion side, and each notch portion 22 is The curling treatment portion of the outer case 2 inside is sufficiently exposed, that is, the space portion 10 on the sealing portion side is of a size that communicates with the outside air.

Therefore, as shown in FIG. 2, when the electrolytic capacitor is mounted on the substrate 12, that is, when the sealing portion side is applied to the mounting surface of the substrate 12, the space 10 formed in the sealing portion is The cutouts 22 formed in the insulating sleeve 4 communicate with the outside air. Therefore, when heated due to the connection by the solder 20, the expanded air is released to the outside air through the cutout portion 22. For this reason, it is possible to prevent the electrolytic capacitor from being pushed up by the expansion of air to cause an inclination or the formation of blowholes in the solder 20, and to enhance the reliability of the circuit device.

In the embodiment, the notches 22 are formed at two positions of the insulating sleeve 4 to allow air to be discharged. However, the notches 22 are formed on the size of the electrolytic capacitor and on the opening side. If the size or shape corresponds to the size of the space portion 10, the purpose can be achieved, and the notch portion 22 may be provided in one place.

[0014]

[Effect of device]

 As described above, according to the present invention, the air that is trapped in the space formed between the board surface and the sealing portion when mounted is prevented from deteriorating without reducing the sealing strength of the outer case. The notch formed on the bottom allows air to be released to the outside air, and the inclination of the electrolytic capacitor during soldering and the blowholes that occur in the solder can be reliably prevented, thus improving the quality and reliability of the circuit device that mounts the electrolytic capacitor. Can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of an electrolytic capacitor of the present invention.

FIG. 2 is a partial cross-sectional view showing a mounting example of the electrolytic capacitor shown in FIG.

FIG. 3 is a vertical cross-sectional view showing a mounting surface portion in a mounting example of a conventional electrolytic capacitor.

[Explanation of symbols]

 2 Outer case 4 Insulation sleeve 10 Space 12 Board 22 Notch

Claims (1)

[Scope of utility model registration request] 1. An electrolytic capacitor in which a surface of an outer case is covered with a sleeve, wherein the sleeve discharges air trapped in a space formed between a sealing portion side of the outer case and a substrate surface. An electrolytic capacitor having a notched portion.