JP7203349B2 - capacitor - Google Patents

Description

The present invention relates to capacitors.

A conductive wire (lead wire terminal) consisting of a single metal wire is connected by soldering to collective electrodes provided on a pair of side surfaces (both end surfaces) of the capacitor element, and the capacitor element to which the conductive wire is connected has an open top surface. In a film capacitor housed in a case, there is a structure in which protrusions are provided on two inner wall surfaces facing each other of the case and protrusions are provided on each conductive wire, and the upper part of the protrusion is in contact with the lower surface of the protrusion. , described in US Pat.

In the film capacitor of Patent Document 1, the two conductive wires are bent outward so that the distance between the two projections is wider than the distance between the two projections in order to bring the projections into contact with the projections. Therefore, before the conductive wire is bent, the distance between the two projections is wider than the distance between the two projections. It is wider than the width of the capacitor element at one solder portion (see FIG. 1 of Patent Document 1).

A groove may be provided at the tip of the projection of the case. In this case, part of the conductive wire is accommodated in the groove (see FIG. 4 of Patent Document 1). As a result, the conductive wire is held by the protrusions so as not to move toward the pair of inner wall surfaces of the case where the protrusions are not provided.

JP 2008-205074 A

In the film capacitor described above, the two projections are positioned outside the two straight conductive wires and the two solders, so that the conductive wires are bent after the capacitor element is housed in the case, as described above. At that time, there is concern that a stress load may be applied to the connection portion of the conductive wire by soldering. In addition, since the gap between both end surfaces of the capacitor element and the inner wall surface on which the protrusion is provided becomes large, there is a concern that the size of the case may become large.

SUMMARY OF THE INVENTION In view of such problems, an object of the present invention is to provide a capacitor in which lead wire terminals connected to electrodes of a capacitor element can be favorably held by a holding portion provided in a case.

A capacitor according to a main aspect of the present invention includes an element unit including a capacitor element having electrodes on both end faces, lead wire terminals connected to the electrodes, and a case accommodating the element unit. . Here, the dimension in the direction along the end surface of the capacitor element is smaller in the first direction in which the lead terminal extends from the electrode than in the second direction perpendicular to the first direction. Each of the lead wire terminals is fixed by soldering to the central portion of the end surface of the capacitor element in the second direction. The element unit is accommodated in the case so that the first direction is the opening direction of the case. The case includes a pair of first inner side faces facing both end faces of the capacitor element and a pair of second inner side faces perpendicular to the pair of first inner side faces. The lead protrudes toward the end face of the capacitor element facing the first inner side surface at the center of the pair of second inner side surfaces in the alignment direction, and the lead wire terminal is restricted from moving in the alignment direction. A retainer is provided for retaining the wire terminal. Further, in the case, the interval between the two holding portions is smaller than the dimension of the element unit at the two solder portions in the direction in which the two end faces of the capacitor element are arranged, and the second inner surface and the The distance from the holding portion is made smaller than the dimension from the end of the capacitor element to the end of the solder on the far side from the end in the second direction. In the element unit, the dimension from the end on the side where the lead wire terminal of the capacitor element extends in the first direction to the end of the solder on the far side from the end is such that the lead wire terminal is the second lead wire terminal. The element unit tilted so as to fall toward the inner surface side is inserted into the case from between the second inner surface and the holding portion, and the lead wire terminal contacts the upper end of the case. When the tilt of the element unit is returned, the solder has a dimension that allows the solder to move toward the inside of the case rather than the holding portion without coming into contact with the holding portion.

ADVANTAGE OF THE INVENTION According to this invention, the capacitor|condenser which can hold|maintain satisfactorily the lead-wire terminal connected to the electrode of a capacitor element by the holding|maintenance part provided in the case can be provided.

The effects and significance of the present invention will become clearer from the description of the embodiments shown below. However, the embodiment shown below is merely an example of carrying out the present invention, and the present invention is not limited to the embodiments described below.

FIG. 1 is a perspective view of a film capacitor in which the opening surface of the case faces upward according to the embodiment. FIG. 2 is an exploded perspective view of the film capacitor according to the embodiment. FIG. 3(a) is a bottom view of the element unit according to the embodiment, and FIG. 3(b) is a bottom view of the case according to the embodiment. FIG. 4(a) is a cross-sectional view taken along line AA' of FIG. 3(b) according to the embodiment, and FIG. FIG. 10 is a diagram showing that the device cannot be inserted into the case while it is in the posture when the device is held. FIG. 5 is a diagram for explaining a procedure for inserting the element unit into the case according to the embodiment; FIGS. 6A and 6B are diagrams for explaining the configuration of a film capacitor according to a modification. FIG.

A film capacitor 1, which is one embodiment of the capacitor of the present invention, will be described below with reference to the drawings. For convenience, front-rear, left-right, and up-down directions are indicated in each figure as appropriate. It should be noted that the illustrated directions only indicate relative directions of the film capacitor 1, and do not indicate absolute directions. Also, for convenience of explanation, some configurations such as "top surface" and "front side surface" may be named according to the direction of illustration.

In this embodiment, the film capacitor 1 corresponds to the "capacitor" described in the claims. Also, the edge electrode 110 corresponds to the "electrode" described in the claims. Further, the left inner wall surface 304a and the right inner wall surface 305a correspond to "a pair of first inner surfaces" described in claims. Further, the front inner wall surface 302a and the rear inner wall surface 303a correspond to "a pair of second inner surfaces" described in claims.

However, the above description is only for the purpose of associating the structure of the scope of claims with the structure of the embodiment, and the above correspondence allows the invention described in the scope of claims to correspond to the structure of the embodiment. It is not limited at all.

FIG. 1 is a perspective view of the film capacitor 1 with the opening of the case 300 facing upward. FIG. 2 is an exploded perspective view of the film capacitor 1. FIG. 3A is a bottom view of the element unit 500, and FIG. 3B is a bottom view of the case 300. FIG. 4(a) is a cross-sectional view taken along line AA' in FIG. 3(b), and FIG. 4(b) shows the case 300 when the element unit 500 is housed in the case 300. FIG. It is a diagram showing that it cannot be inserted into the In FIG. 1, part of the filling resin 400 is drawn with oblique lines, and the remaining part is drawn transparently. In addition, in FIG. 4B, the element unit 500 is drawn in a transparent state for the sake of convenience.

A film capacitor 1 includes a capacitor element 100 , a pair of lead wire terminals 200 , a case 300 and a filling resin 400 . An element unit 500 is configured by connecting a pair of lead wire terminals 200 to the capacitor element 100 . A filling resin 400 is filled in the case 300 housing the element unit 500 , and the filling resin 400 covers the capacitor element 100 and part of the pair of lead wire terminals 200 . The tip portions of the pair of lead wire terminals 200 are exposed from the filling resin 400 and extend below the case 300 .

Film capacitor 1 of the present embodiment can be mounted on a mounting surface such as a printed circuit board, and can be used, for example, as one of the electrical components of vehicles such as automobiles. When the film capacitor 1 is mounted on the mounting surface, the tip portions of the pair of lead wire terminals 200 are inserted into the through holes of the lands provided on the mounting surface and connected and fixed to the lands by soldering.

A detailed configuration of the film capacitor 1 will be described below.

Capacitor element 100 is formed by stacking two metallized films in which aluminum is vapor-deposited on a dielectric film, winding or laminating the stacked metallized films, and pressing them into a flat shape. Capacitor element 100 has a substantially elliptical cylindrical shape, and includes two left and right elliptical end faces 101 and a peripheral surface 102 connecting the two end faces 101 . The peripheral surface 102 is composed of a pair of upper and lower flat surfaces 102a and a pair of front and rear circular arc surfaces 102b. In capacitor element 100, the direction in which flat surfaces 102a are arranged, that is, the vertical dimension is smaller than the direction in which circular arc surfaces 102b are arranged perpendicular to the direction, that is, the dimension in the front-rear direction. End face electrodes 110 are formed on both end faces 101 of the capacitor element 100 by spraying a metal such as zinc. The direction in which the flat surfaces 102a are arranged corresponds to the first direction described in the claims, and the direction in which the circular arc surfaces 102b are arranged corresponds to the second direction described in the claims. Hereinafter, the direction in which the flat surfaces 102a are arranged is referred to as the lateral direction, and the direction in which the circular arc surfaces 102b are arranged is referred to as the longitudinal direction.

The pair of lead wire terminals 200 has a round bar shape and is formed by coating a highly conductive core material such as copper with a plating material such as tin. The upper ends of the pair of lead wire terminals 200 are connected and fixed by solder 120 to the end faces 101 on both sides of the capacitor element 100, that is, to the end face electrodes 110 on both sides. As a result, the pair of lead wire terminals 200 are electrically connected to the end surface electrodes 110 on both sides of the capacitor element 100 . At this time, the connection position of the lead wire terminal 200 to the end surface electrode 110 is the center portion of the end surface 101 of the capacitor element 100, that is, the center portion in the lateral direction and the center portion in the longitudinal direction. Terminal 200 extends straight downward. The solder 120 covers the upper ends of the lead terminals 200 , has a substantially circular shape when viewed from the front of the end face 101 of the capacitor element 100 , and is wider than the outer diameter (diameter) of the lead wire terminals 200 from the end face electrodes 110 . Raised to a slightly higher position.

Case 300 is made of resin, for example, polyphenylene sulfide (PPS). The case 300 is formed in a substantially rectangular parallelepiped box shape and includes a top surface portion 301, a front side surface portion 302, a rear side surface portion 303, a left side surface portion 304, a right side surface portion 305, and an open bottom surface. Each corner of the case 300 has a curved surface shape, and in particular, the corner between the top surface portion 301 and the front side surface portion 302 and the corner portion between the top surface portion 301 and the rear side surface portion 303 have a larger curved surface than the other corners. have a shape.

Inner wall surface 304 a of left side surface portion 304 and inner wall surface 305 a of right side surface portion 305 face end surfaces 101 on both sides of capacitor element 100 when element unit 500 is accommodated in case 300 . An inner wall surface 302a of the front side surface portion 302 and an inner wall surface 303a of the rear side surface portion 303 are perpendicular to an inner wall surface 304a of the left side surface portion 304 and an inner wall surface 305a of the right side surface portion 305 . The four inner wall surfaces 302a, 303a, 304a and 305a are hereinafter referred to as a front inner wall surface 302a, a rear inner wall surface 303a, a left inner wall surface 304a and a right inner wall surface 305a, respectively.

Rectangular parallelepiped legs 306 are formed on the lower surfaces of the front side surface portion 302 and the rear side surface portion 303 at two positions on the left and right sides. When the film capacitor 1 is mounted on a mounting surface such as a printed circuit board, the four legs 306 come into contact with the mounting surface. In addition, ribs 307 extending in the left-right direction are formed on the top surface portion 301 at two locations on the front and rear sides of the inner wall surface 301a. Due to these ribs 307 , when the element unit 500 is accommodated in the case 300 , a gap is created between the peripheral surface 102 of the capacitor element 100 and the top surface portion 301 into which the filling resin 400 enters.

On the left inner wall surface 304a and the right inner wall surface 305a, the front and rear inner wall surfaces 302a and the rear inner wall surface 303a are arranged in the longitudinal direction, that is, at the central portion in the direction in which the front inner wall surface 302a and the rear inner wall surface 303a are arranged, and at the upper end portion, that is, at a position slightly lower than the opening surface of the case 300. , a holding portion 308 is provided so as to protrude inside the case 300 . The holding portion 308 is provided with a U-shaped groove portion 309 at its tip so as to correspond to the cross-sectional shape of the lead terminal 200 . The groove portion 309 has a width substantially equal to the diameter of the lead wire terminal 200 and a depth larger than the radius of the lead wire terminal 200 .

In the case 300, the space C1 (see FIG. 3B) between the two holding portions 308 is the distance between the two solders 120 in the arrangement direction (horizontal direction) of the end faces 101 on both sides of the capacitor element 100. It is smaller than the dimension L1 (see FIG. 3(a)). Therefore, when the element unit 500 is arranged in the center of the arrangement direction (horizontal direction) of the left inner wall surface 304a and the right inner wall surface 305a in the case 300, when viewed from the opening direction of the case 300, the holding portion 308 overlaps the solder 120 and the lead wire terminal 200 , and the position of the groove portion 309 substantially matches the position of the lead wire terminal 200 .

When the film capacitor 1 is assembled, the element unit 500 and the case 300 are turned upside down, and the element unit 500 is accommodated in the case 300 through the opening 300a in the bottom surface of the case 300. FIG.

The element unit 500 is housed in the case 300 so that the direction in which the lead wire terminals 200 extend is aligned with the opening direction of the case 300, but it cannot be inserted into the case 300 in this posture. As described above, the distance C1 (see FIG. 3B) between the two holding portions 308 is smaller than the dimension L1 (see FIG. 3A) of the element unit 500 at the two solder 120 portions, and the solder This is because the portion 120 collides with the holding portion 308 .

Further, as shown in FIG. 4(b), the case 300 is such that the distance C2 between the front inner wall surface 302a (rear inner wall surface 303a) and the holding portion 308 is the side farther from the end of the capacitor element 100 in the longitudinal direction. is smaller than the dimension L2 to the end of the solder 120. Therefore, even if the element unit 500 is moved toward the front inner wall surface 302a as shown in FIG. In this posture, the element unit 500 cannot be inserted into the case 300 .

Therefore, the element unit 500 is inserted into the case 300 as follows.

FIG. 5 is a diagram for explaining the procedure for inserting the element unit 500 into the case 300. FIG. In FIG. 5, the element unit 500 is drawn in a transparent state for the sake of convenience. Here, an example in which the element unit 500 is inserted into the case 300 from between the front inner wall surface 302a and the holding portion 308 will be described. and the holding portion 308 into the case 300 .

Referring to FIG. 5, first, as shown in FIG. The element unit 500 is tilted so that the lead terminal 200 falls toward the front inner wall surface 302a until the angle L4 becomes smaller than the gap C2 between the front inner wall surface 302a and the holding portion 308. FIG. In this state, the element unit 500 is moved toward the front inner wall surface 302 a and inserted into the case 300 from between the front inner wall surface 302 a and the holding portion 308 . If the solder 120 moves further inside the case 300 than the holding portion 308 until the lead wire terminal 200 contacts the upper end of the case 300 as shown in FIG. Tilt is returned. After that, the element unit 500 is moved to the inner wall surface 301a of the top surface portion 301 of the case 300 as shown in FIG. D, and then moved to the center of the case 300 as shown in FIG. While the element unit 500 is moving toward the center, the lead terminal 200 contacts the end of the holding portion 308 . At this time, the end of the holding portion 308 can be avoided by bending the lead wire terminal 200 inward.

When the element unit 500 moves to the center of the case 300 as shown in FIG. At this time, more than half of the lead wire terminal 200 is fitted into the groove portion 309 in the radial direction of the lead wire terminal 200 . The lead wire terminal 200 is held by the holding portion 308 so that the direction in which the front inner wall surface 302a and the rear inner wall surface 303a are aligned (the front-rear direction) and the outward movement of the case 300 are restricted. position. Thus, the housing of the element unit 500 in the case 300 is completed.

Here, as the dimension of capacitor element 100 in the lateral direction increases, the dimension in the lateral direction from the end on the side where lead wire terminal 200 of capacitor element 100 extends to the end of solder 120 on the side farther from that end is As L3 (see FIG. 4(b)) increases, it becomes necessary to tilt the element unit 500 more. If the dimension L3 is further increased, when the element unit 500 is tilted back at the position where the lead terminal 200 contacts the upper end of the case 300, the solder 120 abuts against the holding portion 308 and is caught. The element unit 500 cannot be inserted into the case 300.

Therefore, in the present embodiment, the dimension L3 of the element unit 500 is set so that the lead terminal 200 faces the front inner wall surface 302a so that the element unit 500 can be inserted into the case 300 without being obstructed by the holding portion 308. The element unit 500 tilted so as to fall down is inserted into the case 300 from between the front inner wall surface 302a and the holding portion 308, and the element unit 500 tilts until the lead terminal 200 contacts the upper end of the case 300. When the solder 120 is returned, the solder 120 is sized to move toward the inside of the case 300, that is, toward the inner wall surface 301a of the top surface portion 301, rather than the holding portion 308 without contacting the holding portion 308.

When the element unit 500 is housed in the case 300 , the inside of the case 300 housing the capacitor element 100 is filled with the filling resin 400 . The filling resin 400 is a thermosetting resin such as an epoxy resin, and is injected into the case 300 in a liquid state to a position slightly above the holding portion 308 . After that, when the inside of the case 300 is heated, the filling resin 400 inside the case 300 is cured. Capacitor element 100 is covered with case 300 and filling resin 400 to be protected from moisture and impact.

Thus, the film capacitor 1 is completed as shown in FIG.

<Effect of Embodiment>
As described above, according to the present embodiment, the following effects can be obtained.

In the case 300, the space C1 (see FIG. 3B) between the two holding portions 308 is the distance between the two solders 120 in the arrangement direction (horizontal direction) of the end faces 101 on both sides of the capacitor element 100. Since it is smaller than the dimension L1 (see FIG. 3(a)), the tip of the holding portion 308 can be projected inward to the lead wire terminal 200 portion. Therefore, the lead wire terminal 200 can be held by the holding portion 308 without being bent outward. In addition, since the gaps between the end surfaces 101 on both sides of the capacitor element 100 and the left inner wall surface 304a and the right inner wall surface 305a of the case 300 are unlikely to increase, the case 300 is arranged in the direction in which the left inner wall surface 304a and the right inner wall surface 305a are aligned. Hard to grow.

In case 300, the distance C2 between front inner wall surface 302a (rear inner wall surface 303a) and holding portion 308 is L2 ( 4B), the case 300 is less likely to increase in size in the direction in which the front inner wall surface 302a and the rear inner wall surface 303a are arranged.

Furthermore, in the element unit 500, the dimension L3 (see FIG. 4(b)) from the edge of the lead wire terminal 200 of the capacitor element 100 extending in the lateral direction to the edge of the solder 120 farther from the edge is The element unit 500 tilted so that the lead wire terminal 200 falls toward the front inner wall surface 302a is inserted into the case 300 from between the front inner wall surface 302a and the holding portion 308, and the lead wire terminal 200 is placed on the upper end of the case 300. The dimensions are such that the solder 120 can move toward the inside of the case 300 rather than the holding portion 308 without contacting the holding portion 308 when the element unit 500 is tilted back before contact. Therefore, even if the case 300 is not unnecessarily large, the element unit 500 can be accommodated in the case 300 without being obstructed by the holding portion 308 .

Furthermore, more than half of the lead wire terminal 200 is fitted into the groove portion 309 of the holding portion 308 in the radial direction of the lead wire terminal 200 . This makes it difficult for the lead wire terminal 200 to come off from the groove portion 309 , so that the lead wire terminal 200 can be favorably held by the holding portion 308 . In addition, the dimensional accuracy of the interval between the lead wire terminals 200, which is important when the film capacitor 1 is mounted on a printed circuit board or the like, is improved, and the front and rear direction of each lead wire terminal 200 (the arrangement of the front inner wall surface 302a and the rear inner wall surface 303a) is improved. direction) can be reduced without the conventional jigs and tools.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the application examples of the present invention may be modified in various ways other than the above-described embodiments. It is possible.

For example, as shown in FIG. 6A, film capacitor 1 may use a capacitor element 100A having larger lateral and longitudinal dimensions than capacitor element 100 of the above-described embodiment. . In this case, in element unit 500A, dimension L2 from the end of capacitor element 100 in the longitudinal direction to the end of solder 120 farther from the end is larger than the same dimension L2 of element unit 500 of the above-described embodiment, and is short. Dimension L3 from the end of lead wire terminal 200 of capacitor element 100A extending in the hand direction to the far end of solder 120 is larger than the same dimension L2 of element unit 500 of the above-described embodiment.

When the element unit 500A of this modification is accommodated in the case 300, as shown in FIG. However, when the element unit 500 is tilted again after the lead terminal 200 approaches the upper end of the case 300, the solder 120 does not come into contact with the holding portion 308. is also moved inside the case 300 . Therefore, the element unit 500A of this modified example can also be housed in the case 300 without the solder 120 being caught by the holding portion 308, as in the above-described embodiment.

In addition, in FIG. 6A, the filling resin 400 is drawn transparently for the sake of convenience, and a part of its surface portion is hatched. In addition, in FIG. 6B, the element unit 500A is drawn transparently for convenience.

Further, in the above-described embodiment, the upper end portion of the lead wire terminal 200 is connected by the solder 120 to the center portion of the end surface 101 of the capacitor element 100 in the lateral direction. However, the upper end portion of lead wire terminal 200 may be connected by solder 120 to a position shifted from the central portion in the lateral direction of end surface 101 of capacitor element 100 toward one flat surface 102a.

Furthermore, in the above embodiment, capacitor element 100 is formed of a metallized film in which aluminum is deposited on a dielectric film. It may be formed of a modified film. Alternatively, capacitor element 100 may be formed of a metallized film obtained by vapor-depositing a plurality of these metals, or may be formed of a metallized film obtained by vapor-depositing an alloy of these metals. . In the above-described embodiment, the capacitor element 100 is formed by stacking two metallized films in which aluminum is vapor-deposited on a dielectric film, and winding or laminating the stacked metallized films. Alternatively, the capacitor element 100 may be formed by stacking a metallized film in which aluminum is vapor-deposited on both sides of a dielectric film and an insulating film, and then winding or laminating them. Furthermore, capacitor element 100 may be formed by stacking three or more metallized films and winding or stacking them.

Furthermore, in the above embodiment, the film capacitor 1 was mentioned as an example of the capacitor of the present invention. However, the present invention can also be applied to capacitors other than the film capacitor 1 .

In addition, the embodiments of the present invention can be appropriately modified in various ways within the scope of the technical idea indicated in the scope of claims.

In the description of the above embodiments, terms such as "upper" and "lower" indicate relative directions that depend only on the relative positional relationship of constituent members, and are vertical and horizontal. It does not indicate an absolute direction such as

INDUSTRIAL APPLICABILITY The present invention is useful for capacitors used in various electronic equipment, electrical equipment, industrial equipment, electrical equipment of vehicles, and the like.

1 Film capacitor (capacitor)
100 capacitor element 101 end face 110 end face electrode (electrode)
120 Solder 200 Lead wire terminal 300 Case 302a Front inner wall surface (second inner surface)
303a rear inner wall surface (second inner surface)
304a Left inner wall surface (first inner surface)
305a right inner wall surface (first inner surface)
308 holding portion 309 groove portion

Claims (2)

an element unit including a capacitor element having electrodes on both end faces and lead wire terminals connected to each of the electrodes;
and a case in which the element unit is accommodated,
The dimension in the direction along the end face of the capacitor element is such that the dimension in the first direction in which the lead terminal extends from the electrode is smaller than the dimension in the second direction orthogonal to the first direction,
each of the lead wire terminals is fixed by soldering to a central portion of the end surface of the capacitor element in the second direction;
the element unit is accommodated in the case so that the first direction is the opening direction of the case;
the case includes a pair of first inner side faces facing both end faces of the capacitor element and a pair of second inner side faces perpendicular to the pair of first inner side faces,
Each of the first inner side surfaces protrudes toward the end face of the capacitor element facing the first inner side surface at the center of the pair of second inner side surfaces in the direction in which the pair of second inner side surfaces are arranged. A holding portion is provided for holding the lead terminal so that the movement is restricted,
Said case is
the interval between the two holding portions is smaller than the dimension of the element unit at the two solder portions in the direction in which the two end faces of the capacitor element are arranged;
the distance between the second inner surface and the holding portion is smaller than the dimension from the end of the capacitor element to the end of the solder on the far side from the end in the second direction;
The element unit is
The dimension from the end on the side where the lead wire terminal of the capacitor element extends in the first direction to the end of the solder on the far side from the end is such that the lead wire terminal falls toward the second inner surface side. The tilted element unit is inserted into the case from between the second inner surface and the holding portion, and the tilt of the element unit is returned until the lead terminal contacts the upper end of the case. Sometimes, the size is such that the solder can move to the inside of the case rather than the holding portion without contacting the holding portion.
A capacitor characterized by: A capacitor according to claim 1, wherein
The holding portion is provided with a groove portion at the tip thereof, into which the lead wire terminal can be fitted more than half in the radial direction of the lead wire terminal.
A capacitor characterized by:

Images