JP2006294790A - Case mold type capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a case molded capacitor excellent in reliability and workability so as to solve the problem that the reliability and workability concerning two or more capacitor elements and connection of a bus bar are bad, with respect to the case molded type capacitor used in-vehicle or the like. <P>SOLUTION: There is provided such a composition forming a connecting hole 2b of an almost recess shape which makes a terminal area two places of a diagonal position a little to the perimeter of an electrode formed in the end face of capacitor element 1, by leaving a tongue-shaped soldering part 2a to a bus bar connected with this terminal area, and by cutting out its circumference that the heat at the time of soldering can be centralized efficiently and soldering work can be done now in a short time. Accordingly, it becomes possible to control excessive ripple current in addition to the capability of increasing the reliability of soldering, without imparting a damage to the capacitor element 1 caused by the difficulty in heating by a soldering iron other than a soldering part 2a in the surroundings. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a case mold type capacitor that is used as a smoothing capacitor for a motor-driven inverter circuit for vehicle use, among case mold type capacitors in which a capacitor element using a metallized film is resin-molded in a case. is there.

  In recent years, metallized film capacitors used for inverter devices have been actively developed for downsizing, high performance, and low cost. In addition, since metallized film capacitors used in inverter devices are required to have a high operating voltage, large current, large capacity, etc., a plurality of capacitor elements connected in parallel are accommodated in a case. A case mold type capacitor in which a mold resin is poured into a case has been developed and put into practical use.

  In such case mold type capacitors, those having excellent mechanical strength, high heat resistance temperature, water resistance, and oil resistance have been continuously pursued.

  6 is an exploded perspective view showing the structure of this type of conventional case mold type capacitor, FIG. 7 is a cross-sectional view taken along the line AA of FIG. 6, and in FIGS. 6 and 7, 10 indicates a capacitor element. The capacitor element 10 is formed by winding a metallized film having a metal vapor-deposited electrode formed on one or both sides of a dielectric film made of polypropylene so that the pair of metal vapor-deposited electrodes face each other with the dielectric film interposed therebetween, and zinc By forming a metallicon electrode sprayed with a positive electrode, an anode electrode and a cathode electrode are respectively provided.

  Reference numeral 11 denotes a cathode bus bar, and 11a denotes a cathode terminal for external connection provided at one end of the cathode bus bar 11. The cathode bus bar 11 includes a plurality of capacitor elements 10 arranged in close contact with each other. Each of the cathode terminals 11a is joined to the cathode formed on one end face, and the cathode terminal 11a is pulled out above the capacitor element 10 and exposed from a case 13 described later.

  Reference numeral 12 denotes an anode bus bar, and 12a denotes an anode terminal for external connection provided at one end of the anode bus bar 12. The anode bus bar 12 is arranged in close contact with the capacitor elements 10 in the same manner as the cathode bus bar 11. In this state, each of the capacitor elements 10 is joined to the anode formed on the other end face, and the anode terminal 12a is pulled out above the capacitor element 10 so as to be exposed from a case 13 described later. Thereby, the several capacitor | condenser element 10 is connected in parallel or in series.

  13 is a case made of polyphenylene sulfide (hereinafter referred to as PPS) resin, 14 is a mold resin filled in the case 13, and this mold resin 14 includes a plurality of pieces connected by the cathode bus bar 11 and the anode bus bar 12. The capacitor element 10 is resin-molded in a case 13, and the case 13 is housed in an outer case 15.

  The conventional case mold type capacitor configured as described above is obtained by molding the capacitor element 10 in the case 13 with the mold resin 14 having excellent heat resistance, moisture resistance, and insulation resistance. By using PPS which is excellent in mechanical strength, heat resistance and water resistance and can withstand harsh use conditions, it is possible to provide a case mold type capacitor with higher reliability than before.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2004-146724 A

  However, in the conventional case mold type capacitor, when the plurality of capacitor elements 10 are connected by the cathode bus bar 11 and the anode bus bar 12, the electrodes formed on the end faces of the capacitor elements 10, the cathode bus bar 11 and the anode bus bar 12 are connected. Since the connection is performed by soldering, if the temperature of the soldering part is excessively heated in order to ensure the soldering strength, the metalized film constituting the capacitor element 10 is damaged by this heat. As a result, there was a problem that the performance deteriorated.

  In addition, since the electrodes formed on the end face of the capacitor element 10 are formed by spraying a conductive metal, the dimensional variation is large, and a plurality of such capacitor elements 10 are arranged side by side to the cathode bus bar 11. In addition, even if the anode bus bar 12 is brought into contact with the capacitor element 10, there are things that do not come into contact with each other, and it is necessary to solder the capacitor element 10 that is not in contact with the anode bus bar 12. In addition, it is difficult to ensure the soldering strength.

  In addition, excessive ripple current may flow because it is used for in-vehicle use. For this reason, it is necessary to devise sufficient measures in the number and area of soldering points or the shape and area of the bus bar near the soldering part. Had the problem of being.

  The present invention solves such a conventional problem, facilitates soldering work when a plurality of capacitor elements are connected by soldering with an anode bus bar and a cathode bus bar, and improves soldering reliability and excessive ripple. It is an object of the present invention to provide a case mold type capacitor capable of suppressing current.

  In order to solve the above-mentioned problems, the present invention has two connecting portions as diagonal positions near the outer periphery of the electrode formed on each end face of the capacitor element, and the bus bar connected to the connecting portion has a tongue-like shape. A substantially concave connection hole is formed with the periphery of the soldering part cut out, and the bus bar and the capacitor element are connected by soldering the soldering part provided in the connection hole to the connection part of the capacitor element. It is a configuration.

  As described above, the case mold type capacitor according to the present invention has a configuration in which a tongue-shaped soldering portion is provided only in a portion necessary for soldering and a substantially concave connection hole is provided by cutting out the periphery thereof. Since the heat at the time of soldering can be concentrated efficiently and the soldering work can be performed in a short time, heating by the soldering iron becomes difficult to turn to other than the soldering part, and the capacitor element may be damaged. In addition, not only the reliability of soldering can be improved, but also an effect that excessive ripple current can be suppressed can be obtained.

(Embodiment 1)
In the following, the first aspect of the present invention will be described with reference to the first to third aspects of the present invention.

  1 (a) and 1 (b) are the same plan view and side view showing the configuration of the case mold type capacitor according to the first embodiment of the present invention, and FIGS. 2 (a) and 2 (b) show the connection holes. FIG. 1 is a plan view and FIG. 2 is a side view showing a configuration. In FIG. 1 and FIG. 2, reference numeral 1 denotes a capacitor element formed in a substantially oval shape, and this capacitor element 1 is made of metal on one or both sides of a dielectric film made of polypropylene. The metallized film on which the vapor deposition electrodes are formed is wound so that the pair of metal vapor deposition electrodes are opposed to each other through the dielectric film, and the metallized electrodes are sprayed with zinc on both end surfaces to provide an anode electrode and a cathode electrode, respectively It is configured.

  2 is an anode bus bar joined to the anode side of the capacitor element 1, 3 is a cathode bus bar joined to the cathode side of the capacitor element 1, and the anode bus bar 2 and the cathode bus bar 3 are made of a tin-plated copper plate, A plurality of capacitor elements 1 are connected in parallel or in series by the anode bus bar 2 and the cathode bus bar 3.

  2a is a tongue-shaped soldering portion that becomes an electrode provided on the anode bus bar 2, and 2b is a substantially concave connection hole in which the periphery of the soldering portion 2a is cut out, leaving the tongue-shaped soldering portion 2a. The connection holes 2b including the soldering portions 2a are provided so as to be connected to two positions which are diagonal positions near the outer periphery of the anode formed on the end face of the capacitor element 1, respectively.

  3a is a tongue-shaped soldering portion that serves as an electrode provided on the cathode bus bar 3, 3b is a substantially concave connection hole in which the periphery of the soldering portion 3a is cut out, leaving the tongue-shaped soldering portion 3a. The connection holes 3b including the soldering portions 3a are respectively provided so as to be connected to two positions which are diagonal positions near the outer periphery of the anode formed on the end face of the capacitor element 1.

  2c is a hole provided at a position close to the root portion of the tongue-like soldering portion 2a provided on the anode bus bar 2, and the hole 2c includes a plurality of capacitor elements 1 formed in the substantially oval shape. When arranged, the capacitor elements 1 are provided so as to be arranged on the gaps generated between the arc portions, and the cathode bus bar 3 is similarly provided with the holes 3c.

  3 (a) and 3 (b) show examples of the shape of the tongue-like soldering portion. FIG. 3 (a) shows a taper type soldering portion 2a and FIG. ) Shows a constant width type soldering part 2d, and the tongue-like soldering parts 2a and 2d are inclined in the thickness direction from the root part toward the tip part. The height increase t due to the inclination is configured to be 0.5 to 1.0 mm.

  The result of confirming the solder state according to the soldering time of the case mold type capacitor according to the present embodiment thus obtained is shown in (Table 1), and the result of confirming the solder state according to the solder temperature is shown in (Table 2). The results of confirming the solderability by the shape of the affixed part are shown in (Table 3).

  In (Table 1) and (Table 2), the shape of the soldering part is the constant width type soldering part 2d shown in FIG. 3 (b), and the position of the soldering iron part is controlled so that the bus bar part and The electrode part of the capacitor element was simultaneously heated and automatically soldered. As the solder wire, eutectic solder (composed of 63% tin and 37% lead) was used.

  As is clear from Table 1, it can be seen that the case mold type capacitor according to the present embodiment can perform sufficient soldering with a soldering iron temperature of 390 ° C. and a soldering time of 4 seconds.

  Further, as is clear from Table 2, it is understood that the soldering iron temperature needs to be 390 ° C. when the soldering time is 4 sec.

  As is clear from (Table 3), when the shape of the soldered part is a taper type, the temperature rise is about 10% smaller than that of the constant width type, and the ripple current flowing through the capacitor element is large. It can be seen that the taper type of the soldering portion is more effective. In addition, although the solderability is the same for both shapes, the tapered type formed so that the tip part is narrower than the base part efficiently transfers the heat of the soldering iron to the necessary part of the soldering part. Therefore, stable soldering work can be performed.

  As described above, the case mold type capacitor according to the present embodiment can concentrate the heat at the time of soldering efficiently and perform the soldering operation in a very short time (within 4 seconds / one place). For this reason, the heating by the soldering iron is difficult to turn to other than the soldering portion and the capacitor element 1 is not damaged, and the reliability of the soldering can be improved, and an excessive ripple current is suppressed. It is possible to obtain a special effect that it is possible to perform.

  These effects are obtained by providing tongue-like soldering portions 2a and 3a only at portions necessary for soldering and providing substantially concave connection holes 2b and 3b cut out around the portions. The heat of the soldering iron can be efficiently concentrated on the soldering portions 2a and 3a so that the soldering operation can be performed in a short time. In this case, the reliability of soldering can be improved.

  In addition, the substantially concave connection holes 2b and 3b, which are cut out from the periphery of the solder pieces 2a and 3a in the form of tongues, are formed in pairs near the outer periphery of the anode and cathode formed on the end face of the capacitor element 1. By adopting a configuration in which each is connected to two corner positions, when the excessive ripple current flows through the capacitor element 1, damage applied to the capacitor element 1 can be dispersed and reduced. As a result, the electrical characteristics and the environmental resistance can be improved.

  Further, when the soldering portions 2a and 3a are heated by the soldering iron during the soldering operation by the holes 2c and 3c provided in the positions close to the root portions of the tongue-like soldering portions 2a and 3a, In addition to acting to prevent heat from escaping other than the attaching portions 2a and 3a, the soldering operation can be performed very efficiently, and the holes 2a and 3a are filled with mold resin. As a result, the effect of increasing the strength of the soldering portion can be obtained.

  Further, the tongue-like soldering portions 2a and 3a are inclined in the thickness direction from the root portion toward the tip portion, and the height increase t due to this inclination is set to 0.5 to 1.0 mm. As a result, even when the electrodes formed on the end face of the capacitor element 1 have dimensional variations and the anode bus bar 2 and the cathode bus bar 3 do not contact each electrode of the capacitor element 1 arranged in plural, soldering is performed. Since the portion for performing the soldering is formed in the minimum necessary area, the soldering operation can be performed reliably.

  In addition, since the anode bus bar 2 and the cathode bus bar 3 are made of a tin-plated copper plate, the anode bus bar 2 and the cathode bus bar 3 can be made of a lead-free material, so that a case mold type capacitor that is friendly to the global environment can be provided. It is.

(Embodiment 2)
The second aspect of the present invention will be described below with reference to the second embodiment.

  In the present embodiment, the arrangement of the capacitor elements and the shape of the anode / cathode bus bar of the case mold type capacitor described in the first embodiment are partially different, and other configurations are the same as in the embodiment. The same reference numerals are given to the same parts and the detailed description thereof is omitted, and only different parts will be described below with reference to the drawings.

  4A and 4B are a plan view and a front view showing the configuration of the case mold type capacitor according to the second embodiment of the present invention. In FIG. 4, 1 is a capacitor element formed in a substantially oval shape. In this embodiment, the capacitor elements 1 are arranged in an aligned manner.

  4 is an anode bus bar, 4a is a tongue-shaped soldering portion provided on the anode bus bar 4, and this soldering portion 4a is similar to the anode bus bar 2 of the case mold type capacitor described in the first embodiment. Two portions of the electrodes formed on the end face of the capacitor element 1 are connected portions, and are provided so as to be connected to the two connected portions.

  Reference numeral 5 denotes a cathode bus bar, and the cathode bus bar 5 is similarly provided with a soldering portion 5a (not shown).

  As described above, even when the capacitor elements 1 are arranged and arranged, the above-described embodiment is obtained by connecting the plurality of capacitor elements 1 using the anode bus bar 4 provided with the tongue-like soldering portions 4a. The same effect as that obtained in 1 can be obtained.

  FIG. 5 shows another example in which a plurality of aligned capacitor elements 1 are connected by an anode bus bar. In FIG. 5, 6 is an anode bus bar, and 6a is a tongue-like shape provided on the anode bus bar 6. This is a soldering portion, and this soldering portion 6 a is provided so as to protrude on both sides in the longitudinal direction of the anode bus bar 6, and this soldering portion 6 a connects two places of the electrodes formed on the end face of the capacitor element 1. It is provided so as to be connected to the two connection portions, and the same effect as that obtained in the first embodiment can be obtained.

  The case mold type capacitor according to the present invention does not damage the capacitor element 1 by performing the soldering operation in an extremely short time, and can not only improve the reliability of soldering, but also has an excessive ripple current. This has the effect of being able to be suppressed, and is particularly useful as a smoothing capacitor for an in-vehicle motor-driven inverter circuit.

(A) The principal part top view which showed the structure of the case mold type capacitor | condenser by Embodiment 1 of this invention, (b) The side view (A) The top view which showed the structure of the connection hole, (b) The side view (A), (b) The principal part top view which showed the example of the shape of the soldering part (A) The top view which showed the structure of the case mold type capacitor | condenser by Embodiment 2 of this invention, (b) The front view The principal part top view which showed the other example of the case mold type capacitor | condenser by Embodiment 2 An exploded perspective view showing a configuration of a conventional case mold type capacitor Sectional drawing in the AA line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Capacitor element 2, 4, 6 Anode bus bar 2a, 2d, 3a, 4a, 5a, 6a Soldering part 2b, 3b Connection hole 2c, 3c hole 3,5 Cathode bus bar

Claims (6)

In a case mold type capacitor in which a plurality of capacitor elements are connected by a bus bar provided with a terminal portion for external connection at one end, and this is accommodated in a case and resin-molded by removing at least the terminal portion of the bus bar, the capacitor element Two locations that are diagonal positions closer to the outer periphery of the electrode formed on each end face of the metal plate are used as connecting portions, and the periphery of the bus bar connected to the connecting portions is cut out with a tongue-like soldering portion remaining. A case mold type capacitor in which a bus bar and a capacitor element are connected by providing a substantially concave connection hole and soldering a soldering portion provided in the connection hole to the connection portion of the capacitor element. When a hole is provided at a position close to the root portion of the tongue-shaped soldering portion of the connection hole provided in the bus bar, and each capacitor is formed when a plurality of capacitor elements each having an approximately oval shape are disposed. The case mold type capacitor according to claim 1, wherein the case mold type capacitor is arranged on a gap portion generated between arc portions of the element. 2. The case mold type capacitor according to claim 1, wherein the tongue-shaped soldering portion of the connection hole provided in the bus bar is formed with a narrower tip portion than a root portion. In a case mold type capacitor in which a plurality of capacitor elements are connected by a bus bar provided with a terminal portion for external connection at one end, and this is accommodated in a case and resin-molded by removing at least the terminal portion of the bus bar, the capacitor element Tongue-shaped soldering portions connected to the electrodes formed on the respective end surfaces of the bus bar are provided on at least one side of the bus bar, and the tongue-shaped soldering portions are provided at two positions with respect to one electrode of the capacitor element. Case mold type capacitor provided. The tongue-shaped soldering portion provided on the bus bar is configured to be inclined in the thickness direction from the root portion toward the tip portion, and an increase in height due to the inclination is 0.5 to 1.0 mm. The case mold type capacitor according to claim 1 or 4. The case mold type capacitor according to claim 1, wherein a copper plate on which a silver plating layer is formed is used as the bus bar.

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