JP2002237427A - Surface-mounting electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-mounting electronic part which is equipped with a land pattern that is formed on a circuit board and restrained from getting complicated, and a seat plate and a lead that are kept free from damage even if a vibrating load is imposed on them. SOLUTION: A chip-type aluminum electrolytic capacitor 9 is equipped with a bottomed cylindrical case 2, a capacitor element 1 which is housed in the case 2 and provided with a pair of the leads 16 and 17 implanted upright in it, and the seat plate 3 which is fixed to the case 2 so as to cover its opening. The leads 16 and 17 are made to penetrate through through holes 33 and 33, and their tips are bent along the surface of the seat plate 3. A metal layer 4 formed of a solderable metal is provided to each of the through holes 33 by covering its inner peripheral surface and opening edge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface-mounted electronic component which is surface-mounted on a circuit board.

[0002]

2. Description of the Related Art In recent years, various electronic components surface-mounted on a circuit board have been formed into chips in order to increase the mounting density. For example, as shown in FIG. 5, the capacitor element (1) was housed in a bottomed cylindrical aluminum case (2), and the opening of the case (2) was sealed using a rubber packing (21). A chip type aluminum electrolytic capacitor (90) is known.

The chip type aluminum electrolytic capacitor (9)
0), the capacitor element (1) is, as shown in FIG.
An anode foil (11) made of an etched aluminum foil formed with a chemical conversion film and an opposing cathode foil (12) are overlapped with a separator (13) interposed therebetween, and this is wound into a roll to produce a winding element. Then, the winding element is impregnated with a solid electrolyte. Here, the solid electrolyte is a TCNQ complex salt,
Conductive polymers such as polypyrrole, polythiophene, polyfuran, and polyaniline. The TCNQ is 7,
It means 7,8,8-tetracyanoquinodimethane.

A pair of lead terminals (15) and (15) are drawn out from the anode foil (11) and the opposite cathode foil (12), and pin-shaped anode leads (16) are respectively connected from these lead terminals (15) and (15). ) And the cathode lead (17) are elongated. As shown in FIG. 5, at the end of the capacitor element (1) from which the lead terminals (15) and (15) protrude,
A rubber packing (21) for sealing is fitted, and after the capacitor element (1) is accommodated in an aluminum case (2), a lateral drawing process is performed on the opening end of the case (2). By performing the curling process, the rubber packing (21) is pressed from the surroundings, and the case (2) is sealed.

[0005] A seat plate (30) is attached to the end surface of the aluminum case (2) on the opening side. The seat plate (30) is made of heat-resistant synthetic resin and has two through holes (33) in the center.
(33) has been established. Then, the anode lead (16) and the cathode lead (17) are inserted into the through holes (33) and (33), and the front ends thereof are formed into a flat plate by performing press working, and the seat plate (30) It is bent substantially at right angles along the surface (36). The above chip type aluminum electrolytic capacitor (9
0) is mounted on the circuit board by soldering the flat portions of the leads (16) and (17) to the surface of the land of the circuit board.

As shown in FIG. 7, when the chip type aluminum electrolytic capacitor is surface-mounted on the circuit board (60), the flat portions of the leads (16) and (17) are placed on the surface of the land (6). The chip type aluminum electrolytic capacitor is fixed on the circuit board (60) by the solder (5) while being covered with the solder (5) in a state of being in contact with the lead (16) (1).
The conduction between 7) and the land (6) is ensured.

When the conventional chip-type aluminum electrolytic capacitor (90) is used in an environment receiving a vibration load such as an electric device mounted on a vehicle, the vibration load concentrates on the bent portions of the leads (16) and (17). Therefore, there is a problem that the bent portion is disconnected. In addition, seat plate (30) by vibration
There was a problem of cracking.

Therefore, as shown in FIG. 8, there has been proposed a chip type aluminum electrolytic capacitor in which a pair of auxiliary electrodes (22) and (22) are attached to the surface of a seat plate (31) (Japanese Patent Application Laid-Open No. H10-163,878).
000-21682). In the capacitor, each lead (16)
(17) and the pair of auxiliary electrodes (22) and (22) are each soldered to a land on the circuit board. In the capacitor, since the auxiliary electrodes (22) and (22) are soldered to the lands, the seat plate (30) is fixed on the circuit board, thereby preventing the seat plate (30) from cracking due to vibration. I can do it.

[0009]

However, even in the above-mentioned chip type aluminum electrolytic capacitor, each lead (1
6) It is unavoidable that the vibration load is concentrated on the bent portion of (17), so that the disconnection of the lead cannot be prevented. Further, since it is necessary to form lands for soldering the auxiliary electrodes (22), there is a problem that the land pattern is complicated. Therefore, the object of the present invention is to
It is an object of the present invention to provide a surface-mounted electronic component that does not complicate a land pattern of a circuit board and does not cause damage to leads and a seat plate even when subjected to a vibration load.

[0010]

The surface-mounted electronic component of the present invention is an electronic component that can be surface-mounted on a circuit board,
A bottomed cylindrical outer case, a component element housed in the outer case in which a pair of leads are protruded, and a seat plate attached to an opening of the outer case so as to cover the opening, Each of the pair of leads penetrates a through hole formed in the seat plate, and has a tip portion bent along the surface of the seat plate. A metal layer made of a solderable metal is formed in at least the inner peripheral surface of the through hole of the seat plate. Note that a gap is formed between the surface of the metal layer and the outer peripheral surface of the lead so that the molten solder can enter.

In the above-mentioned surface-mounted electronic component of the present invention, since the metal layer is formed by using a solderable metal, the solder melted in the gap between the surface of the metal layer and the outer peripheral surface of the lead. When the solder is cooled and solidified, the lead is firmly fixed on the circuit board by the solder, and the seat plate is fixed to the lead. As a result, cracking of the seat plate and disconnection of the lead due to vibration are prevented.

In a specific configuration, the metal layer is made of gold,
It is formed of one metal selected from silver, copper, tin, zinc, lead, chromium, cobalt, and nickel, or an alloy of two or more metals. According to the specific configuration,
Soldering to the metal layer is possible.

In another specific configuration, the metal layer comprises:
It is formed to cover the inner peripheral surface of the through hole of the seat plate and at least the opening edge on the circuit board side. According to this specific configuration, since the solder layer covering the bent portion of the lead is formed to cover the lead more widely than in the related art, the connection strength of the lead to the circuit board is improved. In addition, since the seat plate and the circuit board are connected by solder, the seat plate is firmly fixed on the circuit board.

[0014] In still another specific configuration, the metal layer is formed by a preformed metal pipe piece. According to this specific configuration, the metal layer can be easily formed by attaching the metal pipe pieces to the through holes of the seat plate.

[0015]

According to the surface mount electronic component of the present invention, the land pattern of the circuit board does not become complicated. Further, since the seat plate and the lead are fixed to each other by the solder, there is no possibility that the lead and the seat plate are damaged even when receiving a vibration load.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention applied to a chip type aluminum electrolytic capacitor will be specifically described with reference to the drawings.

As shown in FIG. 1, a chip type aluminum electrolytic capacitor (9) of this embodiment has a capacitor element (1).
And a cylindrical aluminum case (2) with a bottom, and the case
(2) a rubber packing (21) for sealing the opening,
It consists of a seat plate (3).

In the capacitor (9), as shown in FIG. 6, a capacitor element (1) has an anode foil (1) having a chemical conversion film formed thereon.
1) and the opposing cathode foil (12) are overlapped with a separator (13) interposed therebetween, and wound up in a roll to produce a winding element, and a conductive polymer layer is formed in the winding element. From the anode foil (11) and the counter cathode foil (12),
A pair of lead terminals (15) (15) is drawn out, and an anode lead (16) and a cathode lead (17) extend from these lead terminals (15) (15).

As shown in FIG. 1, the capacitor element (1) is housed in an aluminum case (2), and the ends of the capacitor element (1) from which the lead terminals (15) and (15) protrude are provided. A rubber packing (21) for sealing is fitted, and seals an opening of the case (2). And the case
By performing lateral drawing and curling on the end on the opening side of (2), the rubber packing (21) is pressed from the surroundings to seal the case (2).

A seat plate (3) made of a heat-resistant synthetic resin is attached to an end surface on the opening side of the aluminum case (2). The seat plate (3) has through holes as shown in FIG. 2 at positions corresponding to the anode lead (16) and the cathode lead (17).
(33) (33) is opened, covering the inner peripheral surface of each through-hole (33) and each opening edge (34), solderable metal, for example, gold, silver, copper, tin, zinc , Lead, chromium, cobalt,
Alternatively, a metal layer (4) made of nickel is formed.
The metal layer (4) has a cylindrical portion (4) covering the inner peripheral surface of the through hole (33).
0) and two flanges (41) (41) covering both opening edges (34) (34).

The anode lead (16) and the cathode lead (17) of the capacitor element (1) are inserted into respective through holes (33) of the seat plate (3) as shown in FIG. It is processed and formed into a flat plate shape, and is bent substantially at right angles along the surface (35) of the seat plate (3). In the chip-type aluminium electrolytic capacitor, the anode lead (16) and the cathode lead (17) are soldered to the surface of the land of the circuit board and mounted on the circuit board by a reflow process.

FIG. 3 shows a state in which the leads (16) and (17) of the chip type aluminum electrolytic capacitor are soldered to the surface of the land (6) of the circuit board (60). In the reflow process, the molten solder (5) enters a gap formed between the surface of the metal layer (4) and the outer peripheral surfaces of the leads (16) and (17). Then, as the solder (5) cools and solidifies, the leads (16) and (17) and the seat plate (3) are fixed to each other. The molten solder (5) is also filled between the land (6) and the flange (41) of the metal layer (4) on the seat plate surface (35) side, and the solder (5) is cooled and solidified. By doing the circuit board (60)
And the seat plate (3) are fixed to each other.

As described above, in the chip-type aluminum electrolytic capacitor according to the present invention, the leads (16) and (17) and the seat plate (3) are fixed to each other by the solder (5) and the land (6). And the seat plate (3) are fixed to each other by the solder (5). Therefore, even if the capacitor receives a vibration load, the vibration load concentrates on the bent portions of the leads (16) and (17). Is not disconnected, and the seat plate (3) does not break due to vibration. Land (6) and seat plate (3)
Are fixed in a large area by the solder (5) filled between the flange (41) of the metal layer (4) and the land (6), so that the land (6) and the seat plate (3) are fixed. And the bent portions of the leads (16) and (17) are covered with a sufficient area by the solder (5), so that the lands (6) of the leads (16) and (17) are ) Is also improved.
Further, since two lands for soldering the two leads (16) and (17) may be formed on the circuit board, the land pattern of the circuit board does not become complicated.

Next, a method of manufacturing the chip type aluminum electrolytic capacitor of this embodiment will be described. In the manufacturing process of the seat plate (3), as shown in FIG.
A metal layer such as gold is plated on the inner peripheral surface and the opening edges (34) and (34) to form a metal layer (4).

In the manufacturing process of the capacitor element (1), first, an aluminum foil is subjected to an etching treatment and a chemical conversion treatment to produce an anode foil (11), and as shown in FIG. The cathode foil (12) is wound into a cylindrical shape via a separator paper (13), and the end is fixed with a stopping tape (14) to produce a winding element. Next, the winding element is
Iron p-toluenesulfonate containing n-butyl alcohol
(III) and dipped in 3,4-ethylenedioxythiophene. As a result, a conductive polymer layer is formed between the anode foil (11) and the counter cathode foil (12), and the capacitor element (1) is obtained.

Chip type aluminum electrolytic capacitor (9)
In the assembling process, first, as shown in FIG. 4 (a), a rubber packing (21) for sealing is fitted to the end of the capacitor element (1) from which the pair of leads (16) and (17) protrude. And then the same figure
As shown in (b), the capacitor element (1) is housed in an aluminum case (2). Subsequently, as shown in FIG. 3 (c), the lateral end of the opening of the aluminum case (2) is subjected to a horizontal drawing process and a curling process, and a rubber packing (21) is pressed from the surroundings to form a case (2). ), A voltage is applied to the capacitor element (1) in a high temperature state, and the anode foil (1) is sealed.
Aging treatment is performed to repair the oxide film damage in 1). Finally, as shown in FIG. 3 (d), each lead (16) (17) is inserted into each through hole (33) of the seat plate (3), and each lead (16) (17)
Of the chip type aluminum electrolytic capacitor according to the present embodiment is formed by pressing the tip portion of the chip-shaped aluminum electrolytic capacitor into a flat plate shape and bending it at substantially right angles along the surface (35) of the seat plate (3).
Assemble (9).

A vibration test was performed using the chip-type aluminum electrolytic capacitor shown in FIG. 1 and the conventional chip-type aluminum electrolytic capacitor shown in FIG. In addition, copper was used as the material of the metal layer (4), and the thickness of the metal layer was 0.16 mm. Each capacitor has a diameter of 10 mm, a length of 8.0 mm, and an output voltage of 16 mm.
V and the capacitance were 150 μF. Vibration test is JIS C
The method is performed in accordance with Section 8.8.3 of 5102, the type of vibration is C, the vibration frequency range is 10 to 2000 Hz, the total amplitude is 1.5 mm, and the vibration time in each of X, Y and Z directions is respectively 6 hours (18 hours in total). Table 1 shows the results of the vibration test.

[0028]

[Table 1]

As is clear from the results shown in Table 1, in the chip-type aluminum electrolytic capacitor of the above embodiment, no break of the lead occurred and no crack of the seat plate occurred. The lead did not break because the lead was fixed to the seat plate by soldering. The reason why the seat plate did not crack was that the seat plate was fixed to the leads by solder and the seat plate was also fixed on the circuit board.

The configuration of each part of the present invention is not limited to the above embodiment, and various modifications can be made within the technical scope described in the claims. For example, the present invention can be widely applied to surface mount electronic components without being limited to chip type aluminum electrolytic capacitors. Also, as a method of forming a metal layer on the inner surface and the opening edge of the through hole of the seat plate,
Although the plating method is adopted, a method of preparing a metal pipe piece in advance and attaching it to the through hole may be adopted. Furthermore, although a polythiophene-based functional polymer was used as the electrolyte, a conventionally known electrolyte such as an electrolytic solution or a TCNQ complex salt can also be used.

[Brief description of the drawings]

FIG. 1 is a sectional view of a chip type aluminum electrolytic capacitor according to the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the capacitor.

FIG. 3 is an enlarged sectional view showing a state where the capacitor is mounted on a circuit board.

FIG. 4 is a diagram illustrating an assembly process of the capacitor.

FIG. 5 is a cross-sectional view of a conventional chip-type aluminum electrolytic capacitor.

FIG. 6 is a partially exploded perspective view of the capacitor element.

FIG. 7 is an enlarged sectional view showing a state in which a conventional chip-type aluminum electrolytic capacitor is mounted on a circuit board.

FIG. 8 is a view showing a surface of a seat plate of another conventional chip-type aluminum electrolytic capacitor.

[Explanation of symbols]

 (1) Capacitor element (2) Case (3) Seat plate (33) Through hole (35) Surface (4) Metal layer (5) Solder (6) Land (9) Chip type aluminum electrolytic capacitor

Continued on the front page (72) Inventor Kazumasa Fujimoto 217 Fukumo, Omachi-cho, Kishima-gun, Saga Prefecture Inside Saga Sanyo Kogyo Co., Ltd. Sanyo Kogyo Co., Ltd. F-term (reference) 5E336 AA04 BB01 CC02 CC53 EE03 GG15

Claims (5)

[Claims] 1. An electronic component surface mountable on a circuit board, comprising: an outer case having a bottomed cylindrical shape; a component element having a pair of leads protruding and housed in the outer case; and an opening in the outer case. And a seat plate attached to the opening so as to close the opening, wherein a pair of leads of the electronic component respectively penetrate through holes formed in the seat plate, and a tip end thereof is a surface of the seat plate. In the surface-mounted electronic component bent along, the through hole of the seat plate covers at least the inner peripheral surface, and a metal layer made of a solderable metal is formed. Surface mount electronic components. 2. The metal layer is formed of one metal selected from gold, silver, copper, tin, zinc, lead, chromium, cobalt, and nickel, or an alloy of two or more metals. The surface-mounted electronic component according to claim 1. 3. The surface-mounted electronic component according to claim 1, wherein a gap through which molten solder can enter is formed between the surface of the metal layer and the outer peripheral surface of the lead. 4. The surface mounting according to claim 1, wherein the metal layer is formed so as to cover an inner peripheral surface of the through hole of the seat plate and at least an opening edge on a circuit element substrate side. Electronic components. 5. The surface-mounted electronic component according to claim 1, wherein the metal layer is formed of a preformed metal pipe piece.