JP6514843B2 - Metallized film capacitor - Google Patents

Description

  The present invention relates to a metallized film capacitor including a capacitor element in which a metallized film is wound or laminated.

  Many metalized film capacitors including a capacitor element in which a metallized film obtained by vapor-depositing a metallized film such as aluminum or zinc on a dielectric film such as a polypropylene film or a polyethylene terephthalate film is used in many cases for electronic devices etc. There is.

  The metallized film capacitor described in Patent Document 1 has a capacitor element housed in a case, and a gap between the case and the capacitor element is filled with a resin to ensure the performance of the capacitor. .

JP, 2012-69717, A

  In the metallized film capacitor of Patent Document 1, when the case is made of metal, in order to ensure insulation of the capacitor element, an insulating element cap having a concave shape is disposed between the case bottom and the capacitor element. There is a need. In addition, it is necessary to dispose an insulating upper lid that faces the inner peripheral side surface of the case near the upper end of the capacitor element and partially closes the opening of the case. The upper lid is provided with a terminal of a capacitor.

  The resin is filled into the case after the element cap is accommodated in the case and the capacitor element with the upper lid is accommodated in the case. Since the distance between the inner peripheral side surface of the case and the element cap is narrow, the resin is difficult to reach, and there is a problem that air bubbles are easily generated in this portion. In addition, since the distance between the inner peripheral side surface of the case and the upper lid is narrow, it is difficult for the resin to reach, and there is a problem that air bubbles are easily generated in this portion. The air bubbles cause the performance of the metallized film capacitor to deteriorate due to moisture absorption. Moreover, if it is going to be filled with resin so that a bubble may not generate | occur | produce, workability will deteriorate.

  An object of the present invention is to provide a metallized film capacitor having a structure in which air bubbles are less likely to occur when the resin is filled.

The metallized film capacitor of the present invention comprises a capacitor element in which a metallized film provided with a vapor deposition electrode on at least one surface of a dielectric film is wound or laminated, and an element electrode formed on both end surfaces of the capacitor element. And a metal case having a bottomed cylindrical shape having an opening, wherein the capacitor element unit is accommodated, and a direction orthogonal to the both end faces of the capacitor element is an axial direction; A resin filled in the metal case, and two insulating covering members arranged to face both end faces of the capacitor element unit accommodated in the metal case and part of side faces connected to the end faces And a plurality of axially extending plurality of radially extending outwardly of the metal case are provided on the outer peripheral side surface of each covering member. Ribs are formed so as to be aligned in the circumferential direction. The tip of the first rib is in contact with the inner circumferential side surface of the metal case.
Further, one of the two covering members is the element cap facing the inner bottom surface of the metal case, and the other covering member of the two covering members is the metal case of the metal case. An upper lid arranged so as to partially close the opening and provided with two terminals, each terminal being connected to each element electrode through a lead, and the resin being at least the upper lid and the resin A gap with a metal case is filled, and both axial ends of the gap are open, assuming that the gap is not filled with the resin.

  According to the present invention, a sufficient gap is secured between the outer circumferential side surface of the covering member and the inner circumferential side surface of the metal case by the first rib, so that the gap is easily filled with the resin. Therefore, generation of air bubbles in the gap can be suppressed.

Further, the outer end surface of the front Symbol element cap, at least one second rib protruding along the axial direction of the metal casing may be formed. According to this, a sufficient gap is secured between the outer end surface of the element cap and the inner bottom surface of the metal case by the second rib, so that the gap is easily filled with the resin. Therefore, generation of air bubbles in the gap can be suppressed.

In this case, the leads connected to the terminals of the hand is, the are connected with the element electrode and the solder formed on the end face facing the element cap in the capacitor element, among the elements cap At least one of the circumferential side surface and the side surface of the capacitor element unit opposite to this, the diameter and the lead of which the plurality of axially extending third ribs projecting toward the other side are connected to the one terminal In the axial direction of the metal case, at least one of the inner bottom surface of the element cap and the end face of the capacitor element unit opposite to the inner surface is formed so as to line up circumferentially at a position not facing the direction At least one fourth rib protruding along the axial direction of the lead connected to the one terminal It may be formed at a position.

  When a lead connected to one of the terminals is connected to the device electrode using solder, it is difficult to control the height of the solder and the solder and the device cap interfere with each other to reduce the capacity of the capacitor device. Since the variation of the insulation distance with the metal case becomes large, the positional accuracy of the capacitor element in the element cap can be enhanced by the third and fourth ribs formed so as not to interfere with the lead. Therefore, the accommodation of the capacitor element is improved, and the variation in the insulation distance from the metal case can be reduced. In addition, since a sufficient gap is secured between the element cap and the capacitor element, the resin can be easily filled in the gap and generation of air bubbles in the gap can be suppressed.

  The first to fourth ribs may be formed on the covering member. According to this, it becomes easy to form the 1st-4th ribs.

  At this time, a plurality of fifth ribs protruding toward the capacitor element and extending in the axial direction may be formed in the circumferential direction on the inner circumferential side surface of the upper lid. According to this, in order to secure a sufficient gap between the inner peripheral side surface of the upper lid and the capacitor element, the resin is more likely to permeate through the gap and further penetrate into the inside of the case. Therefore, generation of air bubbles in the gap can be suppressed.

  Further, at least one of the leads may be rigid and the upper lid may be fixed to the metal case. Since the resin to be filled usually has a specific gravity larger than that of the capacitor element, the capacitor element floats up and the capacitor element comes out of the resin surface. In order to prevent this, a jig (weight) is used as the capacitor element Since it is necessary to dispose the capacitor element on the upper side to prevent the capacitor element from floating, the capacitor element can be prevented from floating without using a jig.

  According to the present invention, a sufficient gap is secured between the outer circumferential side surface of the covering member and the inner circumferential side surface of the metal case by the first rib, so that the gap is easily filled with the resin. Therefore, generation of air bubbles in the gap can be suppressed.

FIG. 1 is a transparent perspective view of a metalized film capacitor according to an embodiment of the present invention. It is a cross-sectional view of the metallized film capacitor in the II-II line of FIG. It is a longitudinal cross-sectional view of the metallized film capacitor in the III-III line of FIG. It is a longitudinal cross-sectional view of the metallized film capacitor in the IV-IV line of FIG. It is the perspective view seen from the upper and lower direction of the element cap contained in the metallized film capacitor shown in FIG. It is the perspective view of the upper cover contained in the metallized film capacitor shown in FIG. 1, and its elements on larger scale.

  A dry type cylindrical metallized film capacitor according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the metallized film capacitor 1 is one in which a capacitor element unit 20 is accommodated in a metal case 10. As shown in FIG. 3, the capacitor element unit 20 includes a capacitor element 21 and element electrodes 22 a and 22 b formed on both end surfaces of the capacitor element 21.

  The capacitor element 21 is formed by winding or laminating a metallized film in which a metal such as aluminum or zinc is vapor-deposited on one side or both sides of a dielectric film such as a polypropylene film or a polyethylene terephthalate film. The element electrodes 22a and 22b are formed by metallikon processing. In the present embodiment, the capacitor element 21 has a cylindrical shape.

  The metal case 10 is made of, for example, aluminum, and has a bottomed cylindrical shape having an opening. The axial direction of the metal case 10 is orthogonal to both end surfaces of the capacitor element 21. The capacitor element 21 is disposed such that the element electrode 22 b faces the inner bottom surface of the element cap 30 described later.

  The metallized film capacitor 1 further includes an element cap 30 and an upper lid 40 which are both covering members. Both end surfaces of the capacitor element unit 20 are covered with an element cap 30 and an upper lid 40. The element cap 30 is an insulating member having a concave shape as shown in FIGS. 5 (a) and 5 (b). The element cap 30 is disposed to face the inner bottom surface of the metal case 10. The inner diameter of the element cap 30 is slightly larger than the outer diameter of the capacitor element 21, and the height thereof is about 1⁄5 of the height of the capacitor element 21. Therefore, the element cap 30 not only faces the lower end surface of the capacitor element unit 20 but also faces a part of the side surface connected to the lower end surface.

  The upper lid 40 is an insulating member, and includes a cylindrical portion 41 and a flat portion 42. The flat plate portion 42 is an elongated plate member fixed to the upper end of the cylindrical portion 41 so as to pass on the central axis of the cylindrical portion 41, and the width thereof is about 1/3 of the diameter of the cylindrical portion 41. As shown in FIGS. 6A and 6B, grooves 42a and 42b are provided at both ends of the upper surface of the flat plate portion 42. As shown in FIG. As shown in FIG. 4, at the upper end of the metal case 10, two projections 10a, 10b having the same width as or narrower than the grooves 42a, 42b are provided at positions corresponding to the grooves 42a, 42b. The projections 10a and 10b of the metal case 10 are engaged with the flat plate portion 42 at the grooves 42a and 42b by bending the metal case 10 at a right angle so that the projections 10a and 10b are horizontal. The upper lid 40 is thereby fixed to the metal case 10. In this state, the flat plate portion 42 faces the upper end surface of the capacitor element unit 20 so as to partially close the opening of the metal case 10. Note that, as a modification, the upper lid 40 may be fixed to the metal case 10 by performing a crimping process using a punch.

  On the upper surface of the flat plate portion 42, two cylindrical projections 42c and 42d which are radially separated are formed. The terminals 51 and 52 of the metalized film capacitor 1 are accommodated in the two protrusions 42c and 42d, respectively. The terminals 51 and 52 respectively project from the upper surfaces of the protrusions 42 c and 42 d and are exposed to the lower surface of the flat plate portion 42.

  The upper cover 40 further includes a pressing plate 43 protruding from a position corresponding to the center of the two protrusions 42 c and 42 d on the lower surface of the flat plate portion 42. The pressing plate 43 has a height substantially equal to the distance from the flat plate portion 42 to the element electrode 22 a of the capacitor element unit 20. An insulating distance between the terminals 51 and 52 exposed to the lower surface of the flat plate portion 42 and the element electrode 22 a is secured by the pressing plate 43.

  The inner diameter of the cylindrical portion 41 is slightly larger than the outer diameter of the capacitor element 21, and the height thereof is about 1⁄4 of the height of the capacitor element 21. Therefore, the cylindrical portion 41 is opposed to a part of the side surface connected to the upper end surface of the capacitor element unit 20.

  The terminal 51 and the element electrode 22 b are connected via a lead (connection copper plate) 61. Similarly, the terminal 52 and the element electrode 22 a are connected via the lead 62. Connection between the leads 61 and 62 and the terminals 51 and 52 is performed by spot welding, and solder is used for connection between the leads 61 and 62 and the device electrodes 22a and 22b. The leads 61 and 62 are copper plates having a thickness of 0.3 mm, and have rigidity to such an extent that they are not deformed by the buoyancy received by the capacitor element unit 20 in the resin 70 described later. Covered with insulating paper. As shown in FIG. 4, the lead 61 is bent in a U-shape such that the height thereof is substantially equal to the distance from the flat plate portion 42 to the element electrode 22b. The lead 61 is in contact with the side surface of the capacitor element unit 20 except for a portion extending in the axial direction of the metal case 10 near the flat plate portion 42. The lead 62 is bent in a U-shape such that the height thereof is substantially equal to the distance from the flat plate portion 42 to the element electrode 22a.

  Since it is difficult to control the solder height used to connect the lead 61 and the device electrode 22b, dimensional variation is likely to occur in the capacitor device unit 20 including the solder.

  The metal case 10 is filled with a resin 70 which is a high-viscosity substance for securing capacitor performance. To manufacture the metallized film capacitor 1, first, the element cap 30 is disposed in the metal case 10, and then the capacitor element unit 20 coupled to the upper lid 40 via the leads 61 and 62 is disposed in the metal case 10. Be done. Thereafter, the upper lid 40 is fixed to the metal case 10, and then the resin 70 is filled into the metal case 10 from between the flat plate portion 42 and the metal case 10.

  As shown in FIGS. 5A and 5B, on the outer peripheral side surface of the element cap 30, eight elongated ribs 30a (first ribs) extending in the axial direction are circumferentially aligned at an equal angle of 45 °. Is formed. The length of the rib 30 a is the same as the height of the element cap 30. Further, as shown in FIGS. 6A and 6B, also on the outer peripheral side surface of the cylindrical portion 41 of the upper lid 40, eight elongated ribs 41a (first ribs) axially extending at an equal angle of 30 °. It is formed to line up in the circumferential direction. The length of the rib 41 a is the same as the height of the cylindrical portion 41. The tips of the ribs 30 a and 41 a are in contact with the inner peripheral side surface of the metal case 10. Thus, a sufficient gap corresponding to the height of the ribs 30a, 41a is formed between the outer peripheral side surface of the element cap 30 and the outer peripheral side surface of the cylindrical portion 41 and the inner peripheral side surface of the metal case 10. The resin 70 is also filled in the gap.

  Four ribs (second ribs) 30 b are formed on the outer end surface (outer bottom surface) of the element cap 30. The four ribs 30b are arranged at equal distances (half the radius of the bottom surface of the element cap 30) from the center of the bottom surface of the element cap 30 so that they form a square in plan view. The lower end of the rib 30 b is in contact with the inner bottom surface of the metal case 10. Thus, a sufficient gap between the outer end surface of element cap 30 and the inner bottom surface of metal case 10 by the height of rib 30 b (between the outer peripheral side surface of element cap 30 and the inner peripheral side surface of metal case 10) (Connected to the gap formed in the above), and the resin 70 is also filled in the gap.

  As shown in FIG. 5A, on the inner circumferential side surface of the element cap 30, eight elongated ribs 30c (third ribs) extending in the axial direction are formed to be circumferentially aligned at an equal angle of 45 °. ing. The rib 30c is formed at the same angular position as the rib 30a. The length of the rib 30 c is the same as the height of the element cap 30. The tip of the rib 30 c is in contact with the side surface of the capacitor element 21. Thus, a sufficient gap corresponding to the height of the rib 30c is formed between the inner peripheral side surface of the element cap 30 and the capacitor element unit 20, and the resin 70 is also filled in the gap.

  Further, four ribs 30 d (fourth rib) and one rib 30 e (fourth rib) are formed on the inner bottom surface of the element cap 30. The four ribs 30 d are circumferentially aligned at an equal angle of 90 ° and connected to the lower end of the rib 30 c. The rib 30e has a cross shape and is formed at the center of the inner bottom surface of the element cap, and the extension directions of the four arms coincide with the direction from the center of the element cap 30 toward the four ribs 30d. The tips of the ribs 30d and 30e are both in contact with the bottom surface of the capacitor element unit 20 (element electrode 22b). Thus, a sufficient gap between the inner bottom surface of element cap 30 and capacitor element unit 20 and the height of ribs 30 d and 30 e (formed between the inner peripheral side surface of element cap 30 and capacitor element unit 20) (Connected to the gap), and the gap is filled with the resin 70.

  In the present embodiment, as shown in FIG. 2, eight ribs 30 c are formed at positions not facing the leads 61 in the radial direction. Further, the four ribs 30 d and one rib 30 e are formed at positions not facing the lead 61 in the axial direction. As a result, since the ribs 30c, 30d, and 30e do not interfere with the lead 61, even if there is a dimensional variation in the capacitor element unit 20 including the solder used to connect the lead 61 and the element electrode 22b. The gap formed between the element cap 30 and the capacitor element unit 20 can be used as a buffer space for containing solder, and the positional accuracy of the capacitor element unit 20 in the element cap 30 can be enhanced. Therefore, the accommodation of the capacitor element unit 20 is improved, and the variation of the insulation distance with the metal case 10 can be reduced.

  As shown in FIG. 6A, on the inner circumferential side surface of the cylindrical portion 41 of the upper lid 40, eight axially extending elongated ribs 41b (fifth ribs) are circumferentially aligned at an equal angle of 30 °. Is formed. The length of the rib 41 b is the same as the height of the cylindrical portion 41. The tip of the rib 41 b is in contact with the side surface of the capacitor element unit 20. Thus, a sufficient gap corresponding to the height of the rib 41b is formed between the inner peripheral side surface of the cylindrical portion 41 of the upper lid 40 and the capacitor element unit 20, and the resin 70 is also filled in this gap. There is.

  In the present embodiment, as described above, the lead 61 connected to the terminal 51 has rigidity, and the upper lid 40 is fixed to the metal case 10. Since the resin 70 filled in the metal case 10 has a specific gravity larger than that of the capacitor element unit 20, if the lead 61 does not have rigidity or if the upper lid 40 is not fixed to the metal case 10, the capacitor element The unit 20 floats up and the capacitor element unit 20 comes out of the resin surface. In order to prevent this, it is necessary to dispose a jig (weight) on the capacitor element unit 20 to prevent the floating thereof, but in the present embodiment, the floating of the capacitor element is prevented without using the jig. it can.

  In the present embodiment, as described above, the ribs 41a and 41b are provided on the cylindrical portion 41, whereby the outer peripheral side surface of the cylindrical portion 41 of the upper lid 40, the inner peripheral side surface of the metal case 10 and the cylindrical portion 41, and the capacitor element Between the unit 20, a sufficient gap corresponding to the height of the ribs 41a and 41b is secured. Therefore, the resin 70 filled into the metal case 10 from between the flat plate portion 42 and the cylindrical portion 41 can easily penetrate the inside of the metal case 10 through the gap. Therefore, generation of air bubbles in the gap can be suppressed.

  Furthermore, in the present embodiment, as described above, by providing the ribs 30a to 30e on the element cap 30, the ribs 30a to 30e are provided between the element cap 30 and the metal case 10 and the capacitor element unit 20, respectively. A sufficient gap is secured for the height of the Therefore, the resin 70 filled into the metal case 10 from between the flat plate portion 42 and the metal case 10 tends to be filled in the gap. Therefore, generation of air bubbles in the gap can be suppressed.

  Further, in the present embodiment, since the first to fifth ribs are all formed on the element cap 30 or the cylindrical portion 41, the ribs are compared to the case where these ribs are formed on the metal case 10 or the capacitor element unit 20. Has the advantage of being easy to form.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various design changes may be made to the above-described embodiments as long as they are described in the claims. It is possible. For example, it is possible to adopt the following modification.
The first rib may be formed on both the element cap 30 and the cylindrical portion 41 and the inner peripheral side surface of the metal case 10 opposite thereto.
-The second rib may be one.
The second rib may be formed on both the element cap 30 and the inner bottom surface of the metal case 10 opposite thereto.
The third rib may be formed on the capacitor element unit 20, or may be formed on both the element cap 30 and the side surface of the capacitor element unit 20 opposed thereto.
-The fourth rib may be one. However, it is preferable to make it radiation shape like embodiment mentioned above.
The fourth rib may be formed on the capacitor element unit 20, or may be formed on both of the element cap 30 and the end face of the capacitor element unit 20 opposed thereto.
-It is not necessary that all of the first to fifth ribs be formed, as long as at least the first rib is formed.
The leads 61 and 62 may not have rigidity. In that case, the pressing plate 43 serves to prevent the capacitor element unit 20 from rising.

Reference Signs List 1 metallized film capacitor 10 metal case 20 capacitor element unit 21 capacitor element 22a, 22b element electrode 30 element cap 40 upper lid 41 cylindrical portion 42 flat plate portion 42a, 42b groove 10a, 10b protrusion 51, 52 terminal 70 resin 61, 62 lead 30a Rib (1st rib)
41a rib (first rib)
30b rib (the second rib)
30c rib (third rib)
30d rib (fourth rib)
30e rib (4th rib)
41b Rib (5th rib)
43 Holding plate

Claims (6)

A capacitor element in which a metallized film having a vapor deposition electrode provided on at least one surface of a dielectric film is wound or laminated, and a capacitor element unit including element electrodes formed on both end surfaces of the capacitor element;
A metal case having a bottomed cylindrical shape having an opening, the capacitor element unit being accommodated, and a direction orthogonal to the both end surfaces of the capacitor element being an axial direction;
A resin filled in the metal case;
And two insulating covering members disposed to face both end surfaces of the capacitor element unit housed in the metal case and part of side surfaces connected to the end surfaces,
A plurality of first ribs projecting radially outward of the metal case and extending in the axial direction are formed on the outer peripheral side surface of each covering member so as to be circumferentially aligned, and the tip of the first rib is formed Contact the inner circumferential side of the metal case,
The covering member of one of the two covering members is an element cap facing the inner bottom surface of the metal case,
The other of the two covering members, the covering member is an upper lid disposed so as to partially close the opening of the metal case, and provided with two terminals.
Each terminal is connected to each element electrode through a lead,
The resin is filled at least in the gap between the upper lid and the metal case,
A metallized film capacitor characterized in that both axial ends of the gap are open, assuming that the gap is not filled with the resin.
The outer end surface of the front Symbol element cap, metalized film capacitor according to claim 1, characterized in that it is at least one second rib protruding along the axial direction is formed in the metal case. The leads connected to the terminals of the hand, are connected with the element electrode and the solder formed on the end face facing the element cap in the capacitor element,
A plurality of third ribs projecting toward the other and extending in the axial direction are connected to the one terminal on at least one of the inner peripheral side surface of the element cap and the side surface of the capacitor element unit opposed thereto. The metal is formed on the inner bottom surface of the element cap and at least one of the end surfaces of the capacitor element unit opposite to the inner surface of the element cap, which are formed to align in the circumferential direction at positions not facing the leads radially The at least one fourth rib protruding along the axial direction of the case is formed at a position not opposed to the lead connected to the one terminal in the axial direction. Metallized film capacitor.   The metallized film capacitor according to claim 3, wherein the first to fourth ribs are formed on the covering member.   The plurality of fifth ribs protruding toward the capacitor element and extending in the axial direction are formed on the inner peripheral side surface of the upper lid so as to be aligned in the circumferential direction. Metallized film capacitor.   The metallized film capacitor according to any one of claims 3 to 5, wherein at least one of the leads has rigidity and the upper lid is fixed to the metal case.

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