JPWO2009013943A1 - Electrolytic capacitor - Google Patents

Abstract

By eliminating the need for a seat plate, it is possible to reduce the height of the capacitor while maintaining the same capacity and low ESR characteristics as a conventional capacitor. A capacitor element, a bottomed case for housing the capacitor element, a sealing member used for sealing the capacitor element at an opening end of the bottomed case, the anode foil, and the cathode foil In an electrolytic capacitor having an anode lead wire and a cathode lead wire connected via a lead tab, the anode lead wire and the cathode lead wire protrude from the sealing member and are bent and mounted toward the outer frame of the bottomed case. A terminal portion connected to the substrate, wherein the sealing member has at least one convex portion on a surface exposed to the outside, and a tip surface of the convex portion, the anode lead wire, and the cathode lead wire The surfaces of the terminal portions connected to the mounting substrate are arranged on substantially the same plane. [Selection] Figure 1

Description

  The present invention relates to an electrolytic capacitor, and more particularly to a self-supporting electrolytic capacitor.

Conventionally, a structure as shown in FIG. 10 is known as a self-supporting electrolytic capacitor. (For example, patent document 1) That is, as shown in FIG. 4, the capacitor | condenser element 1 formed by winding the anode foil 2 and the cathode foil 3 through the separator paper 4 is produced. The capacitor element 1 is cut and heat-treated, and the capacitor element is impregnated with an electrolytic solution or a solid electrolyte is formed, and then stored in a bottomed cylindrical case 9 as shown in FIG. The anode lead wire 7 and the cathode lead wire 8 respectively connected to the anode foil 2 and the cathode foil 3 via the lead tab 6 are inserted into the through holes 106 of the substantially cylindrical sealing member 10 shown in FIG. The opening end of 9 is laterally drawn and curled. Next, a seat plate 11 made of an insulating member having a through hole is inserted, and the anode lead wire 7 and the cathode lead wire 8 projecting from the through hole of the seat plate 11 are pressed, and then outward in the case 9 respectively. The anode lead wire 7 and the cathode lead wire 8 are bent substantially vertically so that they are in a straight line, and the electrolytic capacitor shown in FIG. 10 is manufactured.

In the electrolytic capacitors as described above, there is an increasing demand for a reduction in height with an increase in capacity and a reduction in ESR (Equivalent Series Resistance).
JP 9-246120 A

In order to reduce the height of the capacitor, it is necessary to reduce the size of the capacitor element housed in the case. However, since the capacitance and ESR characteristics of the capacitor depend on the size of the capacitor element, large capacity and low ESR characteristics are required. It was very difficult to reduce the height while maintaining the characteristics.

In addition, the seat plate varies depending on the size of the capacitor element, and has a thickness of about 0.4 to 1.0 mm. It is indispensable to eliminate the seat plate to reduce the height while maintaining the capacitor characteristics. There was a problem that the independence of the capacitor could not be secured if the plate was removed.

In view of the above problems, the present invention provides a capacitor element formed by winding an anode foil and a cathode foil through a separator paper, a bottomed case for storing the capacitor element, and the capacitor element at an open end of the bottomed case. In an electrolytic capacitor having a sealing member used for sealing at a portion and an anode lead wire and a cathode lead wire connected to the anode foil and the cathode foil via a lead tab, the anode lead wire and the cathode lead wire are: Projecting from the sealing member, having a terminal portion that is bent in the direction of the outer frame of the bottomed case and connected to the mounting substrate, and the sealing member has at least one convex portion on the surface exposed to the outside. And the front end surface of the convex portion of the sealing member and the surface connected to the mounting substrate of the terminal portion of the anode lead wire and the cathode lead wire are arranged on substantially the same plane. And wherein the are.
Further, the bottomed case has a curled portion with an open end curled, and the height of the convex portion of the sealing member extends from an exposed surface of the sealing member to the apex of the curled portion. It is characterized by being higher than the height. It is preferable that a groove is formed in the anode lead wire direction and the cathode lead wire direction at the portion where the anode lead wire abuts on the top of the curled portion and the portion where the cathode lead wire abuts, respectively.

Another embodiment of the present invention includes a capacitor element formed by winding an anode foil and a cathode foil through a separator paper, a bottomed case for storing the capacitor element, and an opening end portion of the bottomed case. In an electrolytic capacitor having a sealing member used for sealing with, and an anode lead wire and a cathode lead wire connected to the anode foil and the cathode foil via lead tabs, the sealing member has two through holes. And a groove is provided from the two through holes toward the peripheral edge of the sealing member. Moreover, the notch part is provided in the location where the said anode lead wire and the said cathode lead wire of the opening edge part of the said bottomed case are projected.

According to the structure of the electrolytic capacitor of the present invention, independence can be ensured without a seat plate. In addition, since the seat plate is not required, it is possible to reduce the height of the capacitor while maintaining the capacitor characteristics such as low ESR. Further, the capacity of the electrolytic capacitor can be increased as compared with a self-standing electrolytic capacitor using a conventional seat plate having the same height.

The best mode for carrying out the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a cross-sectional side view of an electrolytic capacitor according to an embodiment of the present invention cut along a plane parallel to a direction in which an anode lead wire and a cathode lead wire are continuous. The electrolytic capacitor of the present invention includes a capacitor element 1, an anode lead wire 7, a cathode lead wire 8, a bottomed case 9, and a sealing member 10 connected to the capacitor element 1 via a lead tab 6. The bottomed case 9 is usually made of metal, and a part or all of the surface of the bottomed case 9 is covered with an insulating member such as an insulating resin. The open end of the bottomed case 9 has a curled portion that is curled after lateral drawing, and the sealing member 10 is a top view (a) and a side view (as viewed from the externally exposed surface 10a in FIG. As shown in b), it has a convex portion 101, and the terminal portions of the anode lead wire 7 and the cathode lead wire 8 are pressed so as to be flattened, respectively, toward the outer frame of the bottomed case 9. It is bent. The front end surface of the convex portion 101 and the surfaces of the terminal portions of the anode lead wire 7 and the cathode lead wire 8 connected to the mounting substrate are located on substantially the same horizontal plane. Thereby, the electrolytic capacitor can stably stand on its own.

  The open end of the bottomed case 9 may not be covered with an insulating member, and even if it is covered with an insulating member, the insulating member may be peeled off during curling. When the exposed metal surface of the bottomed case 9 and the anode and cathode lead wires 7 and 8 come into contact with each other, a short circuit failure or the like may occur. In order to prevent this and to ensure the self-supporting property of the electrolytic capacitor, the height h of the convex portion 101 is the height H from the exposed surface 10a to the outside of the sealing member 10 to the apex of the curled portion. Higher is preferred. In order to further reduce the height of the capacitor, the difference between the height H from the exposed surface 10a to the apex of the curled portion and the height h of the convex portion is preferably small. The sealing member 10 is an insulating member, and is particularly preferably an elastic body. As shown in FIG. 8, the bottomed case 9 is provided with notches 91 at two locations. The two notches 91 are located at locations where the anode lead wire 7 and the cathode lead wire 8 are projected onto the bottomed case 9, respectively. Even if the difference between the height h of the convex portion 101 and the height H from the externally exposed surface 10a of the sealing member 10 to the curled portion is very small due to the cutout portion 91, the bottomed case 9 and the anode The contact between the lead wire 7 and the cathode lead wire 8 can be prevented, and the occurrence of short-circuit defects or the like that may occur due to the contact between the metal surface of the bottomed case 9 and the anode lead wire 7 and / or the cathode lead wire. It can be suppressed. The depth of the notch 91 is not particularly limited, and can be appropriately changed depending on the height of the capacitor element, the diameter of the lead wire, and the like. Further, the width of the notch 91 can be appropriately changed depending on the diameter of the lead wire or the like.

Specifically, the above electrolytic capacitor is manufactured by the following method.

The capacitor element 1 is produced by winding the anode foil 2 and the cathode foil 3 through a separator paper 4 and stopping with a winding tape 5 as shown in FIG. An anode lead wire 7 is connected to the anode foil 2 via a lead tab 6, and a cathode lead wire 8 is connected to the cathode foil 3 via a lead tab 6. An oxide film is formed on at least the surface of the anode foil 2. Thereafter, a polymerization liquid containing a monomer and an oxidant liquid containing an oxidant are prepared, or a mixed liquid containing a monomer and an oxidant is prepared, and the capacitor element 1 is immersed, or the polymerization liquid and the oxidant solution or The mixed solution is applied to the capacitor element 1 to form a solid electrolyte in the capacitor element 1. As the monomer, a heterocyclic compound such as thiophene or pyrrole and / or a derivative thereof, aniline and / or a derivative thereof, or the like is employed. Here, the electrolyte formed in the capacitor element 1 is not limited to the conductive polymer as described above, but may be manganese dioxide, TCNQ complex salt, or the like. Further, the electrolyte is not limited to a solid one but may be an electrolytic solution.
The capacitor element 1 on which the electrolyte is formed as described above is housed in a bottomed cylindrical case 9 provided with a notch 91 as shown in FIG. Next, the sealing member 10 having the convex portion 101 as shown in FIG. 5 is inserted. At this time, the two notches 91 of the bottomed case 9 and the two through holes 106 provided in the sealing member are positioned on the same straight line when viewed from the direction of the externally exposed surface 10a of the sealing member 10. It is preferable to arrange in such a manner. Thereafter, the opening end of the case 9 is subjected to lateral drawing and curling. Thereby, the sealing member 10 clamps the lead tab 6, the anode lead wire 7, and the cathode lead wire 8, and seals the capacitor.
Thereafter, the terminal portions of the anode lead wire 7 and the cathode lead wire 8 protruding from the through hole 106 of the sealing member 10 are pressed, and the surface of the terminal portion connected to the mounting substrate is the tip surface of the convex portion 101. The electrolytic capacitor shown in FIG. 1 is produced by bending it so as to form substantially the same plane.
(Embodiment 2)
FIG. 2 is a cross-sectional side view of the electrolytic capacitor of the present invention cut along a plane parallel to the direction in which the anode lead wire and the cathode lead wire are continuous. The electrolytic capacitor includes a capacitor element 1, an anode lead wire 7, a cathode lead wire 8, a bottomed case 9, and a sealing member 10 connected to the capacitor element 1 through a lead tab 6. The sealing member 10 includes a through hole 106 and a convex portion 102 as shown in FIG. The open end of the bottomed case 9 has a curled portion that is curled after being laterally drawn. The terminal portions of the anode lead wire 7 and the cathode lead wire 8 are pressed so as to be flat, and the tip surface of the convex portion and the terminal portions of the anode lead wire 7 and the cathode lead wire 8 are pressed. Surfaces connected to the mounting substrate are located on substantially the same plane. Further, the height h of the convex portion is slightly higher than the height H from the exposed surface 10a to the outside of the sealing member 10 to the apex of the curled portion. As a result, the self-sustainability of the capacitor can be ensured. Further, in the top part of the curled portion, the portion in contact with the anode lead wire 7 and the portion in contact with the cathode lead wire 8 are respectively in the extending direction of the anode lead wire 7 and the cathode lead wire 8. A groove is provided along. Due to the presence of the groove, contact between the curled portion and the terminal portion of the anode lead wire 7 and the terminal portion of the cathode lead wire 8 can be avoided, so that a short circuit that may occur when the metal is exposed on the surface of the curled portion. Defects and the like can be reduced.

A method for manufacturing the above electrolytic capacitor will be described below.
The capacitor element 1 is formed in the same manner as in the first embodiment, the electrolyte is formed in the capacitor element 1, and the capacitor element 1 is accommodated in the bottomed case 9 shown in FIG. Next, the sealing member 10 in which the convex part 102 shown in FIG. 6 is formed is inserted. After that, the case is laterally drawn and curled. Thereby, the sealing member 10 tightens the lead tab 6, the anode lead wire 7, and the cathode lead wire 8, and seals the capacitor.

Among the tops of the curled curled portions, grooves that contact the anode lead wire 7 and portions that contact the cathode lead wire 8 are grooves along the portions where the anode lead wire 7 and the cathode lead wire 8 contact, respectively. Is made. Thereafter, the terminal portions of the anode lead wire 7 and the cathode lead wire 8 projecting from the through hole 106 of the sealing member 10 are pressed, and the surface of the terminal portion connected to the mounting substrate is the tip surface of the convex portion 101. Then, the surfaces of the terminal portions of the anode terminal 7 and the cathode terminal 8 which are connected to the mounting substrate are bent so as to form substantially the same horizontal plane, thereby producing an electrolytic capacitor. Here, the groove may be formed after pressing the anode lead wire 7 and the cathode lead wire 8 terminal portion and before bending.
(Embodiment 3)
FIG. 3 is a cross-sectional side view of an electrolytic capacitor according to another embodiment of the present invention cut along a line in which an anode lead wire and a cathode lead wire are connected. The electrolytic capacitor includes a capacitor element 1, an anode lead wire 7, a cathode lead wire 8, a bottomed case 9, and a sealing member 10 connected to the capacitor element 1 via a lead tab 6. As shown in FIG. 8, a notch 91 is provided at the opening end of the bottomed case 9, and the anode lead wire 7 and the cathode lead wire 8 are in contact with the bottomed case 9. The insulating properties are maintained by the notches 91. As a result, it is possible to suppress short-circuit defects or the like that may be caused by contact between the bottomed case 9 and the lead wires 7 and 8. The terminal portions of the anode lead terminal 7 and the cathode lead terminal 8 are pressed so as to be flat. The sealing member 10 has a shape as shown in a side sectional view (b) when the top view (a) and (a) are cut along the line XX ′ as seen from the externally exposed surface as shown in FIG. A groove 103 is provided from the two through holes 106 of the sealing member 10 toward the outer edge. The two grooves 103 are preferably on a substantially straight line. The depth of the groove 103 is preferably such that the terminal portions of the lead wires 7 and 8 slightly protrude from the externally exposed surface 10a. The depth of the groove 103 can be appropriately changed depending on the height of the capacitor element 1, the diameters of the lead wires 7 and 8, the thickness of the sealing member 10, and the like. Further, the cutout portions 91 of the bottomed case 9 are provided at locations where the anode lead wire 7 and the cathode lead wire 8 are projected. The depth of the notch 91 is not particularly limited, and can be appropriately changed depending on the height of the capacitor element 1, the height of the bottomed case 9, and the like.

A method for manufacturing the above electrolytic capacitor will be described below.

The capacitor element 1 manufactured in the same manner as in the first embodiment is stored in the bottomed case 9 provided with the two notches 91 shown in FIG. Next, the sealing member 10 with the groove 103 shown in FIG. 7 is inserted so that the exposed surface of the sealing member to the outside is located on the opening end surface of the bottomed case 9. At this time, the two cutout portions 91 are located at the projected portions of the grooves. The opening end of the bottomed case 9 is laterally drawn and curled. The electrolytic lead capacitor 7 shown in FIG. 3 is formed by pressing the terminal portions of the anode lead wire 7 and the cathode lead wire 8 protruding from the through-hole 106 of the sealing member 10 and bending the terminal portions into the grooves 103 of the sealing member 10. Can be made.

Example 1
A capacitor element 1 manufactured by a conventionally known method is housed in a cylindrical bottomed case 9 having a notch 91 shown in FIG. 8 and having a notch 91 and a height of 6.0 mm. The sealing member 10 in which the portion 101 is formed is viewed from above in a direction perpendicular to the externally exposed surface 10a of the sealing member 10 so that the front end surface of the convex portion 101 is located on the opening end surface of the bottomed case, The cutout portion 91 and the center of the through hole 106 provided in the sealing member 10 were inserted so as to be arranged on a substantially straight line. Thereafter, the open end of the bottomed case 9 was laterally drawn and subjected to curling. Next, the terminal portions of the anode lead wire 7 and the cathode lead wire 8 protruding from the through hole 106 of the sealing member 10 are respectively pressed, and connected to the convex portion 101 and the mounting substrate at the end of the anode lead wire 7. The lead wires 7 and 8 were bent so that the surface to be connected to the mounting substrate of the terminal portion of the cathode lead wire 8 and the terminal portion of the cathode lead wire 8 were on substantially the same plane, thereby producing an electrolytic capacitor.
(Example 2)
An electrolytic capacitor was produced in the same manner as in Example 1 except that the sealing member was provided with the convex portion 102 shown in FIG. 6 and the sealing member 10 made of an elastic body was used.
(Example 3)
The capacitor element 1 manufactured by a conventionally known method is accommodated in a cylindrical bottomed case 9 having a notch 91 shown in FIG. 8 and having a notch 91 and a height of 6.0 mm, as shown in FIG. The sealing member 10 made of an elastic body in which the groove 103 is formed is arranged so that the externally exposed surface 10a of the sealing member 10 is positioned slightly below the opening end surface of the bottomed case 9 and the bottomed case 9 It inserted so that the said notch part 91 might be located in the location where the groove | channel 103 of the said sealing member 10 is projected among opening edge parts. Thereafter, the opening end of the bottomed case 9 is laterally drawn and subjected to curling, and then each of the terminal portions of the anode lead wire and the cathode lead wire protruding from the through hole 106 of the sealing member 10 is pressed, and the sealing member Electrolytic capacitors were manufactured by bending the terminal portions of the anode lead terminal 7 and the cathode lead terminal 8 along the ten grooves 103.
Example 4
An electrolytic capacitor was produced in the same manner as in Example 3 except that the sealing member 10 shown in FIG. 11 was used. In addition, the sealing member 10 shown in FIG. 11 consists of elastic bodies.
(Example 5)
The capacitor element 1 manufactured by a conventionally known method is accommodated in a cylindrical bottomed case 9 having a diameter of 6.3 mm and a height of 6.0 mm shown in FIG. 9, and a convex portion 101 as shown in FIG. 5 is formed. The sealing member 10 made of an elastic material was inserted so that the externally exposed surface 10a of the sealing member 10 was positioned slightly below the opening end surface of the bottomed case 9. Thereafter, the opening end of the bottomed case 9 is laterally drawn and subjected to curling, and the center of the through-hole 106 of the sealing member 10 and the center of the top of the curled portion are viewed from the vertically upward direction of the external exposed surface 10a. A groove was provided on a substantially straight line connecting the convex portion 101. Next, the terminal portions of the anode lead wire 7 and the cathode lead wire 8 protruding from the through hole 106 of the sealing member are respectively pressed, and the surfaces of the terminal portions of the anode lead wire 7 and the cathode lead wire 8 that are connected to the mounting substrate. Then, the terminal portion of the anode lead wire 7 and the terminal portion of the cathode lead wire 8 were respectively bent so that the front end surface of the convex portion 101 of the sealing member 10 was located on substantially the same plane, thereby producing an electrolytic capacitor.
(Example 6)
An electrolytic capacitor was produced in the same manner as in Example 5 except that the sealing member 10 having the shape shown in FIG. 6 was used. In addition, the sealing member 10 shown in FIG. 6 consists of elastic bodies.
(Comparative Example 1)
A capacitor element 1 manufactured by a conventionally known method is φ6.3 mm, height shown in FIG. A substantially cylindrical sealing member 10 made of an elastic material as shown in FIG. 11 was inserted in a 6.0 mm cylindrical bottomed case 9. Thereafter, the opening end portion of the bottomed case 9 was laterally drawn and subjected to curl processing, and further, a through hole 106 and a plastic seat plate 11 having a groove provided in the outer edge direction from the through hole 106 were inserted. . Next, the terminal portions of the anode lead wire 7 and the cathode lead wire 8 protruding from the through hole of the seat plate 11 are respectively pressed, the lead wires 7 and 8 are bent along the groove of the seat plate 11, and the electrolytic capacitor is formed. Produced.
(Comparative Example 2)
An electrolytic capacitor was fabricated in the same manner as in Comparative Example 1 except that the bottomed case 9 had a diameter of 6.3 mm and a height of 5.0 mm.

For all the above Examples and Comparative Examples, the height of the produced electrolytic capacitor, the capacitance at 120 Hz, the ESR value at 100 kHz, and the LC (Leak current) after pressurizing 2.5 V for 2 minutes Each was measured. The results are shown in Table 1.

From Examples 1 to 6 and Comparative Example 1, the electrolytic capacitor of the present invention can achieve a product whose height is 0.5 to 1.0 mm lower than the conventional electrolytic capacitor without losing the characteristics of the capacitor. Further, from Examples 1 to 4 and Comparative Example 2, as long as the capacitors have the same height, the present invention can provide an electrolytic capacitor having a larger capacity and excellent ESR characteristics.
The above embodiments are merely illustrative of the present invention and should not be construed as limiting the invention described in the claims. The present invention can be freely modified within the scope of the claims and the scope of equivalent meanings.

It is side surface sectional drawing of the electrolytic capacitor of one Embodiment of this invention. It is side surface sectional drawing of the electrolytic capacitor of another embodiment of this invention. It is side surface sectional drawing of the electrolytic capacitor of another embodiment of this invention. It is a figure which shows the capacitor | condenser element of this invention. It is the top view (a) and side view (b) which looked at the externally exposed surface of one sealing member used for this invention. It is the top view (a) and side view (b) seen from the externally exposed surface of another sealing member used for this invention. It is the top view (a) and side sectional view (b) which looked at the external exposure surface of the sealing member used for this invention. It is a perspective view of one bottom case used for the present invention. It is a perspective view of another bottomed case used for this invention. It is side surface sectional drawing of the conventional electrolytic capacitor. It is the top view (a) seen from the external exposure surface of the sealing member used for the conventional and the electrolytic capacitor of this invention, and the surface view (b) which contacts a mounting board | substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capacitor element 2 Anode foil 3 Cathode foil 4 Separator paper 5 Winding tape 6 Lead tab 7 Anode lead wire 8 Cathode lead wire 9 Bottomed case 10 Sealing member 101 * 102 Protruding part 103 Groove 106 Through-hole 11 Seat plate

Claims (6)

Capacitor element in which anode foil and cathode foil are wound through separator paper, a bottomed case for storing the capacitor element, and a seal used for sealing the capacitor element at an opening end of the bottomed case In an electrolytic capacitor having a member, an anode lead wire and a cathode lead wire connected to the anode foil and the cathode foil via a lead tab,
The anode lead wire and the cathode lead wire protrude from the sealing member, bend each other toward the outer frame of the bottomed case, and have a terminal portion connected to the mounting substrate,
The sealing member has at least one or more convex portions on a surface exposed to the outside, and a surface connected to the mounting substrate of the tip surface of the convex portion and the terminal portions of the anode lead wire and the cathode lead wire. Are arranged on substantially the same horizontal plane. The bottomed case has a curled portion with an open end curled, and the height of the convex portion of the sealing member is higher than the height from the exposed surface of the sealing member to the apex of the curled portion. The electrolytic capacitor according to claim 1, wherein the electrolytic capacitor is high. The bottomed case has a curled portion with an open end curled, and a portion of the top of the curled portion where the anode lead wire abuts and a portion where the cathode lead wire abuts are 4. The electrolytic capacitor according to claim 2, wherein a groove is formed in each of a direction in which the anode lead wire and the cathode lead wire extend. 2. The cutout portion is provided in a portion where the anode lead wire is projected and a portion where the cathode lead wire is projected in the opening end portion of the bottomed case. 4. The electrolytic capacitor according to any one of 3. Capacitor element in which anode foil and cathode foil are wound through separator paper, a bottomed case for storing the capacitor element, and a seal used for sealing the capacitor element at an opening end of the bottomed case In an electrolytic capacitor having a member and an anode lead wire and a cathode lead wire connected to the anode foil and the cathode foil via lead tabs,
The said sealing member has two through-holes, The groove | channel is provided toward the peripheral part of the said sealing member from the said two through-holes, The electrolytic capacitor characterized by the above-mentioned. 7. The cutout portion is provided in a portion where the anode lead wire is projected and a portion where the cathode lead wire is projected in the opening end portion of the bottomed case. The electrolytic capacitor as described.

Images