JP5029293B2 - Cased capacitor - Google Patents

Description

  The present invention relates to a cased capacitor having a structure in which a capacitor element is housed in a case and filled with resin.

A cased capacitor having a structure in which a capacitor element is housed in a case and filled with a resin is used in a power conversion device or the like as a filter capacitor or a snubber capacitor. These capacitors are used in parallel with IGBTs (insulated gate bipolar transistors). In this case, as shown in FIG. 5, the connection terminals 52 and 52 connected to the IGBT 51 and the like are led out from the case opening 53 so as to straddle the case side wall 54 (see, for example, Patent Document 1).
JP 2007-059455 A

  However, in the capacitor described in Patent Document 1, since the connection terminals 52 and 52 connected to the capacitor element 55 are led out from the case opening 53 so as to straddle the case side wall 54, the connection terminals 52 and 52 are provided. This leads to a disadvantage that the lead-out distance becomes longer and the inductance (L component) of the capacitor becomes larger. Moreover, since it is necessary to ensure a predetermined insulation distance from the terminal surface a of the part straddling the case side wall 54, it is also a factor that hinders high density of the inverter and the like.

  The present invention has been made in order to solve the above-described conventional problems, and its purpose is to make it possible to reduce the inductance and to increase the density of inverters and the like. It is to provide a capacitor.

The cased capacitor according to claim 1 is a cased capacitor in which the capacitor element 2 is housed in the case 1 and filled with the resin 5 and the pair of connection terminals 17 and 17 are led to the outside. Both the connection terminal 17 of the first electrode plate 3 connected to the portion 10 and the connection terminal 17 of the second electrode plate 4 connected to the other electrode portion 10 of the capacitor element 2 penetrate the same case side wall 8a. In addition, the first electrode plate 3 and the second electrode plate 4 are overlapped via the insulating layer 21 at a position closer to the case opening 7 than the capacitor element 2. It is characterized by that.

Further, the cased capacitor of claim 2 is a cased capacitor in which the capacitor element 2 is housed in the case 1 and filled with the resin 5 and a pair of connection terminals 17 and 17 are led out to the outside. Both the connection terminal 17 of the first electrode plate 3 connected to the electrode portion 10 and the connection terminal 17 of the second electrode plate 4 connected to the other electrode portion 10 of the capacitor element 2 are the same case side wall 8a. along with being derived in case the outside through, the first electrode plate 3 is at least one of the second electrode plate 4, on the substantially entire surface coplanar connection terminal 17 also electrode plates 3 and 4, including It is formed so that it may be located.

  According to the cased capacitor of claim 1, the lead-out distance of the connection terminal is shorter than in the conventional case where the connection terminal is led out from the case opening so as to straddle the case side wall, and the inductance (L component) of the capacitor is reduced. It becomes possible to reduce. In addition, since the insulation distance that should be ensured is significantly shorter than the conventional example where it was necessary to ensure a predetermined insulation distance from the terminal surface across the side wall of the case, it is possible to increase the density of inverters and the like. Become.

  In addition, according to the cased capacitor, since the current flows in the opposite direction through the overlapping first electrode plate and second electrode plate, the wiring inductance between the first electrode plate and the second electrode plate is reduced.

Further, according to the cased capacitor of claim 2, at least one of the first electrode plate and the second electrode plate is formed such that substantially the entire surface of the electrode plate including the connection terminals is located on the same plane. As a result, the degree of processing in bending is reduced, which facilitates manufacturing and reduces manufacturing costs.

  Next, specific embodiments of the cased capacitor of the present invention will be described in detail with reference to the drawings. As shown in FIGS. 1 and 2, the cased capacitor according to one embodiment of the present invention includes a plurality (two in the figure) of capacitor elements 2 and 2 together with first and second electrode plates 3 and 4. It is configured by being housed in a shallow resin case 1 and filling the case 1 with a resin 5 such as an epoxy resin.

  The case 1 includes a substantially rectangular bottom wall 6 and a rectangular frame-shaped side wall 8 rising from the peripheral end of the bottom wall 6, and an opening formed by opening a side facing the bottom surface of the bottom wall 6. 7 has. The point to be noted here is that a specific side wall 8a of the side walls 8 is formed of a resin flat plate and is detachable with respect to the bottom wall 6 and the other side walls 8, and this resin. This means that the flat plate 8a has through holes 9 and 9 through which connection terminals 17 and 17 to be described later are inserted.

  The capacitor element 2 is a laminated or wound film capacitor element, and is formed thin and flat. Metallicon electrodes 10 and 10 as electrode portions are respectively formed on side surfaces along the opposing thickness direction of the capacitor element 2.

  And the capacitor | condenser element 2 has the surface 11 located in the opening part 7 side of the case 1, the back surface 12 opposed to the bottom surface of the case 1, and the metallicon electrodes 10 and 10 opposed to the side surface of the case 1. In the state, it is stored in the case 1.

  Since the first electrode plate 3 has substantially the same shape as the second electrode plate 4 to be described later, the first electrode plate 3 will be described with reference to the reference numerals attached to the second electrode plate 4, as shown in FIG. A flat plate portion 15 disposed along the surface 11 of the capacitor elements 2, 2 on the opening 7 side, and a pair extending from the flat plate portion 15 and connected to one of the metallicon electrodes 10, 10 of the capacitor elements 2, 2. Internal connection portions 16 and 16 and a connection terminal 17 extending from the flat plate portion 15 on the same plane and protruding outward from the case 1.

  The flat plate portion 15 is formed in a substantially rectangular shape and has a thickness of about 1 mm. The internal connection parts 16, 16 extend downward in an approximately L shape from one end of the flat plate part 15, and the tips thereof are attached to one metallicon electrode 10, 10 with solder 20, 20. The connection terminal 17 extends in the same plane as the flat plate portion from an end portion orthogonal to one end portion (end portion provided with the internal connection portion 16) of the flat plate portion 15 and penetrates the side wall (resin flat plate) 8a of the case 1. It is led out through the hole 9 (see FIGS. 1, 2, and 4).

  As shown in FIG. 3, the second electrode plate 4 includes a flat plate portion 15 disposed along the surface 11 of the capacitor elements 2 and 2 on the opening 7 side of the case 1, and a capacitor extending from the flat plate portion 15. A case 1 that extends from the pair of internal connection portions 16 and 16 connected to the other metallicon electrodes 10 and 10 of the elements 2 and 2 and the flat plate portion 15 and substantially the same as the connection terminal 17 of the first electrode plate 3. And a connection terminal 17 protruding outward.

  The flat plate portion 15 is formed in a substantially rectangular shape and has a thickness of about 1 mm. The flat plate portion 15 is superimposed on the flat plate portion 15 of the first electrode plate 3 with a sheet-like insulator 21 interposed therebetween. The internal connection parts 16, 16 extend downward in a substantially L shape in a direction opposite to the internal connection parts 16, 16 of the first electrode plate 3 from the other end parallel to the one end of the flat plate part 15. The tips are attached to the other metallicon electrodes 10, 10 with solder 20, 20. The connection terminal 17 is bent slightly downward at the end of the flat plate portion 15 and extends in parallel with the connection terminal 17 of the first electrode plate 3 so as to extend on substantially the same plane. Is led out through the through hole 9 of the side wall (resin flat plate) 8a (see FIGS. 1, 2, and 4).

  Next, the procedure for assembling the above cased capacitor will be described. First, the first and second electrode plates 3 and 4 are connected to the capacitor elements 2 and 2. Next, the connection terminals 17 and 17 are inserted into the through holes 9 and 9 of the resin flat plate 8a serving as the side wall of the case 1, and the resin flat plate 8a is fixed to the side of the case 1 (for example, uneven fitting). A cased capacitor is manufactured by filling the case 1 with the resin 5 (see FIG. 4).

  Then, as shown in FIG. 1, the capacitor manufactured as described above is arranged on the side of the IGBT 30 or the like, and the connection terminals 17 and 17 are connected to the IGBT 30 for use. As a result, in the cased capacitor of the above embodiment, the lead-out distance of the connection terminals 17 and 17 is shorter than in the conventional case, and the inductance (L component) of the capacitor can be reduced. Further, since the connection terminals 17 and 17 penetrate the case side wall 8a and the terminal surface a is covered with the resin, it is not necessary to secure an insulation distance, so that it is possible to increase the density of the inverter and the like. Become.

  In this case-containing capacitor, the current flows in the opposite directions to the flat plate portions 15 and 15 of the first and second electrode plates 3 and 4 that are overlapped with each other, and the magnetic field generated by the current is partially By canceling out, the wiring inductance inside the case 1 can be reduced.

  Furthermore, since the first electrode plate 3 is configured such that the flat plate portion 15 and the connection terminal 17 are positioned on the same plane, the degree of processing by bending is reduced, and the manufacturing cost can be reduced. In addition, this is substantially the same for the second electrode plate 4, and therefore, a capacitor can be provided at low cost.

  Although specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the present invention. For example, the first electrode plate 3 and the second electrode plate 4 are arranged in the case 1 so as to be vertically stacked on the opening 7 side of the capacitor elements 2 and 2. Alternatively, the second electrode plate 4 may be disposed closer to the bottom wall 6 than the capacitor elements 2 and 2. The connecting terminals 17 and 17 preferably have a thickness of about 0.5 to 2.6 mm and a width of about 8 to 200 mm. However, the present invention is not limited to this.

1 is a longitudinal sectional view of a cased capacitor according to an embodiment of the present invention. It is the perspective view similarly. It is a perspective view which shows arrangement | positioning of the electrode plate with respect to a capacitor | condenser element. It is a longitudinal cross-sectional view which expands and shows the principal part of the said capacitor | condenser with a case. It is a longitudinal cross-sectional view of the conventional cased capacitor | condenser.

Explanation of symbols

  1 .. Case 2 .. Capacitor element 3.. First electrode plate 4.. Second electrode plate 5 .. Resin 7 .. Opening 8a .. Case side wall (resin flat plate) 9.・ Through hole, 10 ..Side electrode part, 11 ..Capacitor element surface, 12 ..Capacitor element back surface, 15 ..Plate part, 16 ..Internal connection part, 17 ..Connection terminal, 21. body,

Claims (2)

A case-containing capacitor in which a capacitor element (2) is housed in a case (1) and filled with a resin (5) and a pair of connection terminals (17) and (17) is led out to the outside, and one of the capacitor elements (2) Of the first electrode plate (3) connected to the electrode portion (10) of the second electrode plate (4) connected to the other electrode portion (10) of the capacitor element (2). Both the connection terminal (17) penetrates the same case side wall (8a) and is led out of the case , and the first electrode plate (3) and the second electrode plate (4) are a capacitor element. A capacitor with a case, wherein the capacitor is overlaid via an insulating layer (21) at a position closer to the case opening (7) than (2) . A case-containing capacitor in which a capacitor element (2) is housed in a case (1) and filled with a resin (5) and a pair of connection terminals (17) and (17) is led out to the outside, and one of the capacitor elements (2) Of the first electrode plate (3) connected to the electrode portion (10) of the second electrode plate (4) connected to the other electrode portion (10) of the capacitor element (2). Both the connection terminal (17) penetrates the same case side wall (8a) and is led out of the case, and at least one of the first electrode plate (3) and the second electrode plate (4) is A cased capacitor, wherein the electrode plates (3) and (4) including the connection terminal (17) are formed so that substantially the entire surface is located on the same plane .