JP4419416B2 - Metallized film capacitors - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the structure of a film capacitor used in various electric and electronic circuits.
[0002]
[Prior art]
In recent years, inverters have been developed in industrial equipment, and there is a demand for miniaturization and weight reduction. In addition, in order to support high voltage and high frequency of the output power supply, many film capacitors may be mounted in parallel on the printed circuit board mounting product, so miniaturization of the film capacitor is indispensable for miniaturization of the power supply and equipment. Improvements are being made.
[0003]
Hereinafter, a conventional capacitor will be described with reference to FIGS. FIG. 12 is a diagram showing a conventional capacitor element and a configuration using the same.
(A) is the metallized film block diagram of the conventional capacitor | condenser element, (b) shows the longitudinal cross-sectional view of the capacitor | condenser using the conventional capacitor | condenser element.
[0004]
FIGS. 13A and 13B are diagrams showing a winding state of a conventional capacitor element, where FIG. 13A is a winding state diagram of a center forming pin, and FIG. 13B is an enlarged view of a core part of the capacitor element.
[0005]
FIG. 14 is a diagram showing the shape of a conventional capacitor element, where (a) is a plan view seen from the terminal side of the terminal fitting, (b) is a front view seen from the front side of one capacitor of the terminal fitting, c) shows a side view of the terminal fitting as seen from the capacitor side.
[0006]
FIG. 15 shows a configuration diagram of a conventional flat capacitor element. Further, FIG. 16 is a diagram showing a capacitor using a conventional high-frequency compatible capacitor element, in which (a) is a cross-sectional view seen from the lead wire drawing side, and (b) is a diagram showing a front view in vertical section. .
[0007]
First, the structure of the conventional metallized film is demonstrated using FIG. As shown in FIG. 12A, the metallized film 101 is obtained by depositing a metal film electrode on a film, and is wound around a cylindrical core part 100. Further, as shown in FIG. 12 (b), the metallized film 101 is wound with the core portion forming pre-winding film 102, and the exterior film 103 serving as insulation protection for the capacitor element is formed on the outermost periphery. Then, a metal layer 105 is provided on the upper and lower end surfaces of the capacitor element 104, one end of the lead wire 107 is connected to the metal layer 105, and the other end is connected to a terminal 106 for drawing out an electrode. Then, the capacitor element 104 is built in the outer case 108. In addition, an insulating plate 109 for fixing the electrode 106 is provided above the terminal 106 from which the electrode is drawn, and the exterior case 108 is filled with a filling resin 110. Reference numeral 111 denotes a core, and 112 denotes an insulating sheet.
[0008]
A conventional method for manufacturing a capacitor having the above configuration will be described. As shown in FIGS. 12A and 12B, a metallized film 101 is wound around the core portion 100 of the capacitor element 104. Next, in order to insulate the upper metal layer 105 and the lead wire 107 from each other, an insulating sheet 112 is attached to the capacitor element with a tape or the like. The lead wire 107 connects the metal layer 105 provided on the end face of the capacitor element 104 and the terminal 106 for drawing out the electrode by welding, and the insulating plate 109 to which the terminal 106 is fixed is fitted and fixed to the outer case 108. Yes. Further, the lead wire 107, the terminal 106 for drawing out the electrode, the capacitor element 104, and the insulating sheet 112 are inserted into the outer case 108 in a connected state, and the filling resin 110 is injected into the outer case 108 to ensure insulation. . The capacitor element 104 is provided with an exterior film layer 103 made of PP or PET for insulating protection of the metallized film in the assembly process.
[0009]
Here, the core part 100 of the cylindrical capacitor element shown in FIG. 12A is formed by winding the core part forming interior film 102 for several tens of turns to form a film layer of several millimeters. Is wound on the outside.
[0010]
  In addition,Core 111The reason for using the metal layer 105FormingTherefore, when the zinc fine particles are sprayed and formed, it is necessary to prevent the zinc fine particles from entering the core portion 100 and short-circuiting the metal layers 105 of the upper and lower electrodes. Is inserted.
[0011]
Here, as shown in FIG. 12, the core 111 has a conical shape or the like, and is devised to improve the insertion property. In addition, if the core 111 is smaller than the diameter of the hollow portion at the winding center, the hollow portion is liable to collapse if it enters too far, so the diameter on the side opposite to the insertion tip portion of the core 111 is that of the hollow portion at the winding center. It is necessary to make it larger than the diameter so that it does not completely enter the interior. For this reason, the core 111 partially protrudes from the end face of the capacitor element, and the metal layer 105 overlaps the core 111 and forms a protruding portion at the center. Therefore, in consideration of the protrusion, the storage case size of the capacitor element has to be designed to be large in advance, which has been a barrier to miniaturization.
[0012]
Next, a conventional method for producing a metallized film using the core forming inner film 102 will be described. The core forming inner film 102 can be continuously produced in the form of a long roll. It is made of PET film and has a thickness of 10 to 100 μm. The core portion-forming interior film 102 is wound after 10 to 50 turns and then cut, and the metallized film 101 is wound around the wound end portion after cutting to form a capacitor element.
[0013]
In addition, as another method, instead of using the core-forming pre-winding film 102, instead of the core-forming pre-winding film 102, the deposited metal part of the metallized film 101 is scattered by electric discharge machining to ensure insulation, As shown in FIG. 13A, there is a method in which a portion 101a in which insulation of the metallized film 101 is ensured is wound through a slit portion 115 of a winding bobbin 114, and then the winding bobbin 114 is removed. In this case, the cylindrical capacitor element is mainly crushed into the flat element shown in FIG. However, there is variation in characteristics due to film stress at the corners of the metallized film due to flattening, and the round capacitor element shows better characteristics, so it is desirable to reduce the size without making it flat. .
[0014]
Moreover, the core part after extracting the winding bobbin 114 after forming the part which ensured insulation of the core part formation pre-winding film 102 or the metallized film 101 by the method shown in FIG. As shown in FIG. 13 (b), the film located in the slit portion 115 of the winding bobbin 114 has a shape that vertically cuts the central portion of the core as the pre-winding film 113. Then, when the core 111 is inserted to fill the central cavity, the core 111 is conical and the tip is located at the center of the cavity as shown in FIG. There is a possibility that the leading end of the will interfere and deform during insertion. For this reason, zinc fine particles forming the metal layer may enter, and insulation and short-circuit defects may occur.
[0015]
Here, a method of using the core 114 of a dedicated resin molded product as the core of the capacitor element without using the core forming pre-winding film 102 is also considered, but the cost has been increased. Moreover, when it was set as the shape which can respond to mechanization, there was a limit in the minimum outer diameter dimension which has sufficient intensity | strength, and it could not be made a small diameter.
[0016]
Further, as a terminal metal fitting shape of a printed circuit board mounting component for high frequency and large current, a hook-shaped terminal metal fitting having excellent solder cracking properties and heat cycle characteristics shown in FIGS. 14 and 16 is generally used. Also, in order to cope with high frequency and large current, the terminal shape is a band shape, and it is necessary to solder and connect directly to the metal layer of the capacitor element without using a lead wire. Furthermore, in order to mount on a printed circuit board, a terminal having a high inter-terminal pitch accuracy that can be inserted into a hole of the printed circuit board is required. If the pitch accuracy between terminals is poor, the hole diameter must be increased, which adversely affects solder cracking and heat cycle characteristics. In addition, if the position of the terminal fitting is deviated from the center of symmetry of the circular case, the space must be increased to prevent interference with the adjacent case. It was a barrier to miniaturization.
[0017]
In addition, the said prior art has the description in the patent document 1 or the patent document 2, for example.
[0018]
[Patent Document 1]
JP-A-3-89507 (FIG. 1)
[Patent Document 2]
Japanese Patent Laid-Open No. 10-303058 (page 4-6, FIG. 1)
[0019]
[Problems to be solved by the invention]
However, in such a conventional configuration, when the core is inserted, it interferes with the core forming film, deforms the core, and when the core forming film and the metallized film are combined, the film is so thin that the core There is a problem that the capacitor is easily deformed due to interference at the time of insertion, and the capacitor cannot be reduced in size.
[0020]
Also, if the core on the element end face side is flat when the core is inserted into the capacitor element, it becomes convex due to the adhesion of metal particles, and the terminal pitch accuracy is deteriorated when assembling the terminal fitting, and the element dimensions are large. There were problems such as.
[0021]
In addition, if the shape of the terminal fitting connected to the electrode portion of the capacitor element and connected to the outside is flat, there is a problem that the size becomes large and high frequency cannot be handled. In addition, there is a problem that the terminal pitch accuracy of the printed circuit board terminal fittings for large currents is not high, and it takes too much time to attach.
[0022]
[Means for Solving the Problems]
  In order to solve the above problems, the metallized film capacitor of the present invention isThe terminal fitting connected to the metal layer at the end of the capacitor element has a curved portion having a diameter larger than the outer diameter of the capacitor element, and has a convex portion that contacts the outer end of the capacitor element. It is arranged substantially concentrically with the element. Further, the metallized film capacitor of the present invention includes a core having an inclined surface inclined in one direction at an insertion tip part, and an electrode different from a terminal metal fitting, in a hollow part at a winding center around which the metallized film is wound. A structure having an insulating plate that insulates the terminal fitting from the terminal fitting, having a space for fitting the terminal fitting, and further sandwiching the terminal fitting having a convex portion that contacts the outer end of the capacitor element between the outer case and the insulating plate It was.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0026]
(Embodiment 1)
1A and 1B are diagrams showing a capacitor element according to the present embodiment and a configuration using the capacitor element. FIG. 1A is a configuration diagram of a metallized film of the capacitor element, and FIG. 1B is a longitudinal section of a capacitor using the capacitor element. The figure is shown. 2A and 2B are diagrams showing a winding state of the capacitor element and the like in the present embodiment, where FIG. 2A is a winding state diagram of the center forming pin, and FIG. 2B is an enlarged view of the core part of the capacitor element.
[0027]
1 (a) and 1 (b), 1 is a core of the capacitor element, 2 is a metallized film obtained by depositing a metal film electrode on the film, 3 is an exterior film for insulating protection of the capacitor element, 4 is a capacitor element, 5a and 5b are metal layers provided on both end faces of the capacitor element 4, 6 is a terminal for drawing out an electrode, 7 is a lead wire, 8 is an outer case in which the capacitor element 4 is accommodated, and 9 is an insulating plate to which the terminal 6 is fixed. Reference numeral 10 denotes a filling resin, and 13 denotes an insulating sheet. Reference numeral 6a denotes a connection fitting for connecting the metal layer 5a and the terminal 6.
[0028]
  In the capacitor having such a configuration, the lead wire 7 is connected by welding the metal layer 5b provided on the lower surface of the metal layers 5a and 5b provided on the upper and lower end faces of the capacitor element 4 and the terminal 6 for drawing out the electrode. The insulating plate 9 to which the terminal 6 is fixed is attached to the outer case 8.MatingIt is fixed. The insulating sheet 13 ensures insulation between the upper metal layer 5a and the lead wires 7 having different polarities. Further, the lead wire 7 and the capacitor element 4 are inserted into the exterior case 8 in a connected state, and a filling resin 10 is injected to ensure insulation. The capacitor element 4 is provided with an exterior film layer 3 made of PP for insulating protection of the metallized film in the assembly process.
[0029]
Further, the capacitor element 4 has a cavity 1a at the winding center of the metallized film 2, and the core 1 is inserted from the upper and lower openings of the cavity 1a. A connection fitting 6 a is connected to the terminal on the upper metal layer 5 a side of the capacitor element 4 and is connected to the terminal 6.
[0030]
Next, a method for forming the core part of the capacitor will be described with reference to FIGS. In FIG. 2A, 11 is a winding bobbin of a winding machine for winding the metallized film 2 of the capacitor element 4, and 12 is a slit portion of the winding bobbin of the winding machine. The metallized film 2 is made of 4 μm single-sided vapor-deposited PP. The metallized film 2 is secured by insulating the vapor-deposited metal at each tip of about 10 cm. The metallized film 2 is wound around a φ4 mm winder. The metallized film 2 is wound by the winding bobbin 11 through the slit portion 12 of the bobbin 11. And after winding to predetermined length and making it cylindrical shape, the winding bobbin 11 is extracted and the capacitor | condenser element 4 which has the cavity 1a is obtained.
[0031]
In addition, it is necessary in order to prevent the short circuit between different poles by exposing the electrode part to a cavity part to scatter the vapor deposition metal of the front-end | tip part of the winding of the metal film 2, and to ensure insulation. Further, the portion of the metallized film 2 that was located in the slit portion 12 of the winding bobbin 11 is left as a film 14 that cuts the hollow portion vertically through the center of the winding core.
[0032]
Next, the shape of the core 1 inserted into the cavity 1a formed at the winding center position of the capacitor element 4 will be described with reference to FIGS.
[0033]
FIG. 3 is a diagram showing an embodiment of the first core, wherein (a) is a plan view (b) is a front view (c) is a side view.
[0034]
As shown in FIG. 3, the core 1 has an insertion tip 1b near the outer peripheral side surface 1c, and has an inclined surface 1d inclined with the insertion tip 1b as the tip. That is, the core 1 has an inclined surface inclined in one direction at the insertion tip. This eliminates as much interference as possible with the film 14 that vertically cuts the cavity 1a formed at the winding center of the capacitor element 4, reduces friction between the core 1 and the film 14 that vertically cuts the cavity 1a, and is easily inserted. it can. By setting it as such a shape, the core 1 becomes insertable from the both-ends opening part of the cavity part 1a inside without deform | transforming the metallized film layer of the cavity part 1a vicinity. When the insertion is completed, the openings on both sides of the cavity 1a are closed, and the metal fine particles can be prevented from entering when the metal layers 5a and 5b are formed.
[0035]
In the present embodiment, the core 1 has a cylindrical shape with a circular cross section except for the inclined portion. This is because a circular cross section can most easily suppress the frictional force and can be easily inserted. .
[0036]
In the present embodiment, the material of the core 1 is POM. However, other than POM, for example, ABS, PC, or the like may be used.
[0037]
Moreover, in this Embodiment, although the metal part of a metal vapor deposition film was made to be metal non-evaporation so that a metal part may not be contained in the film which enters the hollow part 1a of a winding center, it uses for metal vapor deposition. The same effect can be obtained by using a non-deposited film other than the film. And when this non-deposited film is used, it is possible to use a different material from the metal vapor deposited film, so the film thickness can be changed, and by making it thicker than the metal deposited film, the friction at the time of core insertion can be reduced. On the other hand, it becomes difficult to deform and can be easily inserted. In addition, in this Embodiment, the said effect was confirmed by using the film on which metal vapor deposition is 4 micrometers, and using the 30-micrometer PET film for the non-deposition film used for the hollow part of a winding center.
[0038]
Furthermore, another embodiment of the core 1 will be described with reference to FIG. 4A and 4B are diagrams showing examples of the second core in the present embodiment, wherein FIG. 4A is a front view, FIG. 4B is a side view, and FIG. 4C is a plan view seen from the bottom.
[0039]
  In FIG. 4, 22 is a recess provided in the center of the end opposite to the insertion tip of the core 1, and the core 1 provided with such a recess 22 is a hollow at the center of winding as shown in FIG. Two are inserted into the part 1a from both sides. Thereby, the core 1 inserted into the cavity 1a of the capacitor element 4 has the metal fine particles of the metal layers 5a and 5b,Entering into the cavity 1aTo prevent. At this time, the core 1 is slightly protruded from the both end faces 4a of the capacitor element 4 and further provided with a recess 22 in the core 1, so that the metal layer adheres and protrudes further when the metal layers 5a and 5b are formed. prevent. As a result, when the capacitor element 4 is to be placed in a small case, it can be prevented that the protrusion interferes with the case or the like due to the protrusion and affects the pitch accuracy between the terminals 6.
[0040]
That is, by providing the concave portion 22, it is possible to prevent the metal layer from adhering to the concave portion 22 so that it does not have a protruding shape. Therefore, when the metal layers 5 a and 5 b and the terminal fitting 6 a are connected, the terminal 6 from which the electrode is drawn is fixed. Since the insulating plate 9 is stabilized, the accuracy of the pitch between terminals is improved. In addition, the recessed part 22 makes a manufacturing process easy by making it cylindrical, and can prevent the protrusion of a metal layer more efficiently by forming in the center part of an end surface.
[0041]
As described above, according to the present embodiment, a small capacitor can be obtained by inserting a core having an inclined surface inclined in one direction at the insertion tip portion into a hollow portion that can be wound around the metallized film. Can be formed.
[0042]
Further, according to the present embodiment, by forming the cavity portion of the capacitor element with the non-deposited film, the core can be inserted without further deformation of the cavity portion, and the miniaturization can be realized.
[0043]
In addition, according to the present embodiment, the concave portion is provided on the end surface opposite to the insertion side, so that the protrusion of the metal layer can be prevented and the accuracy of the pitch between terminals can be improved.
[0044]
(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS.
[0045]
  In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. FIG. 5 shows the present embodiment.CapacitorFIG. 6 is a view showing the first terminal fitting in the present embodiment, and FIG. 6A is a side view and FIG. 6B is a front view.
[0046]
In the present embodiment, the difference from the first embodiment is that the core 1 inserted into the cavity 1a of the capacitor element 4 is not inserted into the cavity on the same side as the opening side of the case 8, but on the opposite side. Only the core 1 is inserted, and the terminal 6 and the lead wire 7 in the first embodiment are integrally formed to constitute the terminal fitting 23a.
[0047]
First, the core 1 was inserted only under the capacitor element 4 as shown in FIG. Then, the non-metal vapor deposition film is formed in the cavity of the capacitor element 4 so that it is difficult to be deformed. As a result, even in only one of the inserted cores, the metal of the metal layer 5 is conducted through the cavity. It is possible to prevent the layers 5 from being short-circuited, and by eliminating the upper core 1, it is possible to reduce the protruding portion due to the metal layer 5, and it is possible to suppress restrictions on the shape of the terminal fitting 23 b.
[0048]
In addition, the terminal metal fitting 23b also integrates the terminal 6 and the connection metal fitting 6a in the first embodiment. Moreover, the shape of the terminal metal fitting 23 is a structure as shown in FIG.
[0049]
By adopting such a configuration and shape, the protrusions when forming the metal layers 5a and 5b can be reduced, and the element shape can be reduced in size, and the stability of the mounting accuracy during assembly such as terminal plate fixing and terminal metal fitting soldering can be improved. it can.
[0050]
Furthermore, another embodiment of the shape of the terminal fitting 23 will be described with reference to FIG. FIGS. 7A and 7B are diagrams showing an example of the second terminal fitting in the present embodiment, where FIG. 7A is a front view and FIG. 7B is an enlarged view of an arrow cross section. As shown in FIG. 7B, the terminal fitting 23a has a curved portion 23c, and the curved portion 23c is curved with a diameter larger than the diameter of the capacitor element 4 in FIG. That is, the terminal fitting 23a has a larger diameter than the outer periphery of the cylindrical capacitor element 4, and has a shape along the capacitor element.
[0051]
The terminal fitting 23a is made of copper, has a thickness of 0.8 mm, and a width of 10 mm. In addition, the case and the capacitor element in the present embodiment have a cylindrical shape, and the terminal metal fitting 23a has a curved portion. If the conventional flat shape is used, a dead space is formed between the case and the flat terminal metal fitting. The reason why a space is generated and only a small capacitor element is included for the diameter of the case is to reduce a useless space and realize a small capacitor.
[0052]
As described above, according to the present embodiment, it is possible to effectively use a small space and realize downsizing by using a terminal fitting whose cut surface is curved with a diameter larger than the capacitor element diameter. Note that the same effect can be obtained even if the terminal fitting shape in the present embodiment is used in the first embodiment.
[0053]
(Embodiment 3)
Next, Embodiment 3 of the present invention will be described with reference to FIG.
[0054]
8A and 8B are diagrams showing the capacitor in the present embodiment, where FIG. 8A is a cross-sectional view taken along the arrow, and FIG. 8B is a view showing a front view in a vertical cross section.
[0055]
Reference numeral 24 denotes an insulating plate obtained by integrating the insulating plate 9 and the insulating sheet 13 shown in the first embodiment, and has an L-shape. Further, as shown in FIG. 8B, the insulating plate 24 is flat at the top, but the side portion is provided with a space portion 24a as shown in FIG. 8A, and a terminal is provided in the space portion 24a. The metal fitting 23a is fitted, and is fixed by being sandwiched between the insulating plate 24 and the case 8 in the radial direction of the capacitor element 4.
[0056]
Here, the effect of sandwiching and fixing the terminal fitting 23a between the case 8 and the insulating plate 24 will be described. That is, when the terminal fitting 23 a is fitted into the space 24 a of the insulating plate 24 and the terminal fitting 23 a is sandwiched and fixed between the case 8 that houses the capacitor element 4 and the insulating plate 24, the terminal fitting 23 a Since it is restrained by the case 8, it can be arranged symmetrically with respect to the central axis of the case 8, and the eccentricity between the terminal fitting 23a and the case 8 can be reduced, so that the inter-terminal pitch accuracy of the connection terminals 23a and 23b can be improved.
[0057]
  As described above, according to the present embodiment, the terminal metal fitting is connected between the insulating plate and the capacitor element storage case.MatingBy doing so, the positions of the terminals can be arranged symmetrically with respect to the center of the circular case, and the pitch accuracy between the terminals is improved.
[0058]
Furthermore, another example of the terminal fitting of the present embodiment will be described with reference to FIG. FIG. 9 (a) shows another example of the terminal fitting 23a in the present embodiment, and FIG. 9 (b) shows a longitudinal sectional view of a metallized film capacitor using the same.
[0059]
The terminal fitting 23a in the present embodiment has a side cross-sectional shape curved with a diameter larger than the diameter of the capacitor element 4, similarly to the terminal fitting shown in FIG. Further, as shown in FIGS. 9A and 9B, the terminal fitting 23a is provided with a protrusion 25 that is brought into contact with the outer peripheral portion of the side surface of the capacitor element 4 on the curved portion on the side surface of the terminal fitting.
[0060]
Thus, by providing the terminal metal part 23a with the protrusion 25 on the side surface of the capacitor element 4, the insulating plate 24 ensures insulation between the one metal layer part 5a and the terminal metal part 23a. In the present embodiment, the thickness of the insulating plate 24 is 1 mm.
[0061]
That is, when the terminal fitting 23a is assembled, if the protrusion 25 is not provided, the capacitor element 4 and the terminal fitting 23a cannot be arranged in parallel, and the tip of the terminal fitting 23a is inclined, and the terminal fitting 23a and The accuracy of the pitch between the terminals of 23b deteriorates. Therefore, by providing this protrusion 25, when assembling the terminal fitting 23a, the capacitor element 4 and the terminal fitting 23a can be arranged in parallel, the tip of the terminal fitting 23a is not inclined, and the terminal fitting 23a and The accuracy of the inter-terminal pitch 23b can be improved.
[0062]
As described above, according to the present embodiment, the cross-sectional shape is curved with a diameter larger than the capacitor element diameter, and further, the convex portion is formed in the side circumferential direction of the capacitor element, so that the inter-terminal pitch accuracy is higher. Capacitor can be realized.
[0063]
Next, setting of the optimum core diameter of the core 1 in the present embodiment will be described. FIG. 10 is a diagram showing the relationship between the outer diameter of the core 1 and the outer diameter of the capacitor element 4. The plotted point is that a PP film with a thickness of 4 μm is used, and a capacitor with a width of 40 mm and a withstand voltage of DC 600 V is 30 μF. The outer diameter of the core 1 at that time and the outer diameter of the capacitor element 4 at that time are shown.
[0064]
From FIG. 10, it can be seen that when the core diameter is changed from 2 mm, the outer diameter of the capacitor element when the core diameter exceeding 5 mm is changed increases abruptly at the bending point 26. If the core diameter is smaller than 2 mm, it is difficult to manufacture the bobbin including the formation of the slit portion. And even if it is other than the above-mentioned capacitor element conditions, such a bending point position is almost the same as long as the outer diameter of the capacitor element is between 30 and 40 mm. It can be seen that it is effective for miniaturization of the substrate mounting type.
[0065]
As described above, by setting the core diameter to 2 to 5 mm, it is possible to realize a cylindrical small capacitor corresponding to a printed circuit board and having an outer diameter of about 35 mm.
[0066]
Next, the optimum film thickness used in this embodiment will be described. FIG. 11 is a diagram showing the relationship between the film thickness and space loss. The plotted points are the film thickness and space loss when a PP film with a thickness of 4 μm is used and a capacitor with a width of 40 mm and a withstand voltage of DC 600 V is made 30 μF. Indicates. Here, the space loss refers to a useless space generated on the board when a plurality of cylindrical capacitors are arranged on the printed board. And as shown in FIG. 11, when the film thickness is changed from 2 μm, the dead space suddenly increases at the boundary point 27 of the space loss when the film thickness is changed beyond 4 μm. Recognize. FIG. 11 shows that when the film thickness is increased, the outer diameter of the capacitor itself is naturally increased and the space loss is increased correspondingly when a capacitor having the same specification is produced. And if the film thickness is less than 1 μm, the price of the film will be drastically expensive, so it is difficult to put it to practical use. Therefore, by setting it to 1 to 4 μm or less, it is effective for downsizing the printed circuit board mounting type. Recognize.
[0067]
As described above, by setting the film thickness to 1 to 4 μm, a small cylindrical capacitor corresponding to a printed circuit board having a diameter of about 35 mm can be realized.
[0068]
Note that the same effect can be obtained even if the shape and configuration of the terminal fitting, the core diameter, and the film thickness in the present embodiment are used in the first and second embodiments.
[0069]
【The invention's effect】
As described above, according to the present invention, the core can be inserted without being deformed to the winding center of the film, and so on. Further, by providing a recess in the core, the accuracy of the terminal pitch can be increased and workability can be improved.
[Brief description of the drawings]
FIG. 1 (a) Metalized film configuration diagram in Embodiment 1 of the present invention
(B) Longitudinal sectional view of the metallized film capacitor according to the first embodiment of the present invention.
FIG. 2 (a) Winding situation diagram of center forming pin
(B) Enlarged view of the core of the capacitor element
FIG. 3A is a plan view showing an embodiment of a first core.
(B) Front view showing an example of the first core
(C) Side view showing an example of the first core
FIG. 4A is a plan view showing an embodiment of a second core.
(B) Front view showing an example of the second core
(C) Side view showing an example of the second core
FIG. 5 is a longitudinal sectional view of a metallized film capacitor according to Embodiment 2 of the present invention.
FIG. 6A is a side view showing an embodiment of a first terminal fitting.
(B) Front view showing an embodiment of the first terminal fitting
FIG. 7A is a side view showing an example of a second terminal fitting.
(B) Front view showing an example of the second terminal fitting
FIG. 8 (a) is a cross-sectional view of the metallized film capacitor according to the third embodiment of the present invention as viewed in the direction of the arrows.
(B) Longitudinal sectional view of a metallized film capacitor according to Embodiment 3 of the present invention
9A is a diagram showing an example of a terminal fitting having a protrusion. FIG.
(B) Longitudinal sectional view showing an example of a metallized film capacitor using a terminal fitting having a protrusion.
FIG. 10 is a diagram showing the relationship between the core diameter and the element outer diameter.
FIG. 11 is a diagram showing the relationship between film thickness and space loss.
12A is a diagram of a metallized film of a capacitor element of a conventional example. FIG.
(B) Cutting cross-sectional arrow view from the side of the conventional capacitor
FIG. 13A is a winding state diagram of a center forming pin of a conventional capacitor.
(B) Enlarged view of the core of the conventional capacitor element
FIG. 14A is a plan view of a conventional capacitor terminal fitting viewed from the terminal side.
(B) Front view of conventional capacitor
(C) Side view of conventional capacitor
FIG. 15 is a configuration diagram of a flat capacitor element of a conventional capacitor.
FIG. 16A is a cross-sectional view of a conventional high-frequency capacitor element viewed from the lead wire drawing side.
(B) Longitudinal sectional view of a conventional high frequency capacitor
[Explanation of symbols]
1 core
1a Cavity
1b Insertion tip
1d inclined surface
2 Metallized film
4 Capacitor elements
5a, 5b Metal layer
8 Exterior case
9 Insulation plate
13 Insulation sheet
22 recess
23a Terminal fitting
23c Curved part
24 Insulation plate
25 Protrusion

Claims (11)

A substantially cylindrical capacitor element having a metal layer at the end in the width direction of the wound film, and a terminal fitting connected to the metal layer, which is formed by winding a metallized film deposited with metal on a dielectric film. The terminal fitting has a curved portion having a diameter larger than the outer diameter of the capacitor element, and has a convex portion that hits the outer end of the capacitor element, and the curved portion is substantially concentric with the capacitor element. Metalized film capacitors placed on the An insulating plate that insulates the electrode portion different from the terminal fitting from the terminal fitting, and an exterior case containing a capacitor element. The insulating plate includes a space portion into which the terminal fitting is fitted. The metallized film capacitor according to claim 1, wherein the metalized film capacitor is sandwiched between an outer case and the insulating plate. A substantially cylindrical capacitor element having a metal layer on both side ends in the width direction of the wound film, by inserting a core into a hollow portion of a winding center where a metallized film deposited with metal on a dielectric film is wound; Terminal cores connected to the metal layer, the core has an inclined surface inclined in one direction at the insertion tip, and the terminal metal is a curved portion having a diameter larger than the outer diameter of the capacitor element. A metallized film capacitor having a convex portion that contacts the outer end portion of the capacitor element and having the curved portion arranged substantially concentrically with the capacitor element. An insulating plate that insulates the electrode portion different from the terminal fitting from the terminal fitting, and an exterior case containing a capacitor element. The insulating plate includes a space portion into which the terminal fitting is fitted. The metallized film capacitor according to claim 3 , wherein the metalized film capacitor is sandwiched between an outer case and the insulating plate. 5. The metallized film capacitor according to claim 3 , wherein the metallized film is wound around the cavity at the winding center of the metallized film using a non-metal-deposited film having a thickness greater than that of the film used for the metallized film. 6. The metallized film capacitor according to claim 3 , wherein the core has a substantially cylindrical shape excluding an inclined portion. The metallized film capacitor according to any one of claims 3 to 6 , wherein the core is provided with a recess at an end opposite to the insertion tip. The metallized film capacitor according to claim 7, wherein the recess has a columnar shape and is provided at the center of the end. A capacitor element is incorporated, and an exterior case having an opening is provided. The capacitor element has a core inserted only in one side opening of the cavity, and the opening of the cavity not inserted in the core is the exterior case. The metallized film capacitor according to any one of claims 3 to 8, wherein the metallized film capacitor is disposed so as to be on the opening side. The metallized film capacitor according to any one of claims 3 to 9, wherein a winding center core diameter is 2 to 5 mm. The metallized film capacitor according to claim 3 , wherein the film thickness is 1 to 4 μm.

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