JP2019021868A - Manufacturing method of wound film capacitor and wound film capacitor - Google Patents

Abstract

To provide a wound film capacitor which aims at further improvement of high temperature environmental characteristics in accordance with a new knowledge concerning the temperature dependence of a wound film capacitor.SOLUTION: A manufacturing method of a wound film capacitor 1 according to the present invention includes a laminate forming step S1 of forming a laminate 9 of insulating films 7 and 8 by alternately superimposing first and second conductive layers 5 and 6 and first and second insulating films 7 and 8, a wound body forming step S2 of winding the laminate 9 around a core 11 to form a wound body 2, an electrode forming step S4 of forming first and second electrodes 3 and 4 on both sides in the width direction of the wound body 2, and a preliminary firing step S5 of preliminarily firing the wound body 2 provided with the first and second electrodes 3 and 4.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for manufacturing a wound film capacitor and a wound film capacitor.

  For example, in an electric vehicle (EV) and a hybrid electric vehicle (HEV), an inverter is used to drive the AC motor by converting the DC power of the battery into AC power. A DC power supply circuit (converter, battery, etc.) connected to the inverter switching circuit is generally called a DC link, and the DC power supply voltage is called a DC link voltage. A large-capacitance capacitor called a DC link capacitor is connected to the DC link of the inverter in parallel with the DC power supply to compensate for an instantaneous load fluctuation caused by the switching circuit (see, for example, Patent Document 1).

Capacitors used for the above applications are required to have the following characteristics.
(1) The ability to instantaneously store and release large amounts of energy to compensate for instantaneous load fluctuations,
(2) In order to prevent a situation where the circuit does not operate properly due to a temperature change, the temperature dependence of the dielectric constant is small, and (3) it operates normally even in a high temperature environment.

  Therefore, the present applicant has proposed a capacitor having a predetermined film winding structure in order to satisfy the above characteristics (see Patent Document 2). That is, Patent Document 2 discloses a wound body in a form in which two conductive layers and two insulating films are alternately wound in a roll shape, and both sides in the width direction of the wound body. A wound type film capacitor has been proposed in which a pair of electrodes is provided, and at least one of the two insulating films is a glass film.

JP-T-2004-52496 Gazette Japanese Patent Application No. 2016-111164

  According to the capacitor described in Patent Document 2, since at least one of the insulating films is a glass film, the temperature dependence of the dielectric constant without lowering the dielectric constant is achieved by taking advantage of the property of glass that oxygen vacancies hardly occur. Can be reduced. Moreover, the area of the electrode per unit volume can be significantly improved by taking the form which wound the glass film with the conductive layer. Therefore, by configuring the capacitor with a wound body in the form of a roll of a film made of glass and a conductive layer, while increasing the capacitance per unit volume of the capacitor, due to temperature changes, The situation where the circuit does not operate properly can be effectively prevented. Therefore, it is possible to provide a relatively small capacitor capable of storing a large amount of energy and having excellent high temperature environmental characteristics.

  On the other hand, the capacitor having the above-described configuration is formed of two or more kinds of materials such as a metal film as a conductive layer as well as a glass film, or a base resin that constitutes an electrode together with metal particles. For this reason, there are still many unclear points about the temperature dependence of the capacitor as a whole, and it is considered that there is room for further improvement toward the provision of capacitors that are practical.

  In view of the above circumstances, the present specification solves the problem of providing a wound film capacitor that is further improved in high-temperature environmental characteristics, based on new knowledge about the temperature dependence of the wound film capacitor. Technical issues to be considered.

  The solution to the above problem is achieved by the method for manufacturing a wound film capacitor according to the present invention. That is, in this manufacturing method, the first and second conductive layers and the first and second insulating films are the first conductive layer, the first insulating film, the second conductive layer, and the second insulating film. A wound body in the form of a roll wound in an overlapping state in the order of the film, provided on one side in the width direction of the wound body, in contact with the first conductive layer and separated from the second conductive layer And a second electrode provided on the other side in the width direction of the wound body and in contact with the second conductive layer and separated from the first conductive layer. At least one of the two conductive layers is a method of manufacturing a wound film capacitor formed of a metal, and is calcined after the first electrode and the second electrode are provided on the wound body. Characterized by what to do. The term “calcination” as used herein means that the wound body provided with the first and second electrodes is subjected to heat treatment at a temperature at which oxidation of the metal forming at least one of the conductive layers starts or higher. It means applying. Further, in the present specification, the width direction of the wound body is a direction orthogonal to both the longitudinal direction and the thickness direction of the first or second insulating film in a state constituting the wound body. Means.

  As a result of verifying the temperature dependence of a wound film capacitor, in particular, a wound film capacitor in which a conductive layer is formed of a metal, the inventors have determined a predetermined value for a wound body provided with at least a pair of electrodes. It has been found that when heat treatment is performed at a temperature, the temperature dependence of the capacitance exhibited by the wound film capacitor changes before and after the heat treatment. Specifically, when the temperature of the wound film capacitor is raised before the heat treatment at the predetermined temperature (that is, after the electrode is provided, the heat treatment is not completed, and the finished product is obtained). On the other hand, in the case of a wound film capacitor that has been heat-treated at the predetermined temperature, the capacitance of the capacitor starts to decrease at a predetermined temperature. It has been found that the temperature does not change much even when the temperature of (2) is exceeded (capacitance is substantially maintained). Here, since the discoloration accompanying oxidation was visually recognized in a part of at least one conductive layer of the wound film capacitor that was heat-treated at the predetermined temperature, the conductive layer was formed at the predetermined temperature. The present inventors inferred that the temperature is such that the metal starts to be oxidized or higher. When the wound film capacitor is heat-treated at a predetermined temperature or higher, the conductive layer is oxidized to form an oxide film on the surface, and a part of the surface of the conductive layer is appropriately covered, but the oxidation is constant. In order not to proceed further, it was speculated that the inside of the conductive layer remained in a non-oxidized state, and necessary and sufficient conductivity could be maintained. The present invention has been made on the basis of the above knowledge, and after providing a pair of electrodes on a wound body obtained by alternately laminating two conductive layers and two insulating films and winding them in a roll shape, The calcination is performed by calcining. In this way, by subjecting the wound body to heat treatment at a predetermined temperature in advance, it is possible to suppress or maintain a decrease in capacitance due to temperature rise. Therefore, it is possible to provide a wound film capacitor that further improves the high-temperature environmental characteristics related to the capacitance and has improved reliability and practicality.

  In the method for manufacturing a wound film capacitor according to the present invention, from the viewpoint of implementation, calcining is performed, and the wound body provided with the first and second electrodes is placed at room temperature (for example, see JIS Z 8703). ) To calcination by heating to a temperature at which the oxidation of the metal forming the first and second conductive layers starts together.

  Moreover, in the manufacturing method of the winding type film capacitor which concerns on this invention, you may perform calcination by heating the winding body provided with the 1st and 2nd electrode to 125 degreeC or more.

  The inventors of the present invention have found from the experimental results to be described later that when the wound body provided with a pair of electrodes is heated to 125 ° C. or more, a decrease in capacitance can be suppressed with a higher probability. Therefore, by heating the wound body to 125 ° C. or higher, it is possible to effectively suppress a situation in which the electrostatic capacity of the wound film capacitor including the wound body after heat treatment decreases as the temperature rises, or the temperature Regardless of this, the size of the electrostatic capacity can be maintained.

  Or in the manufacturing method of the winding type film capacitor which concerns on this invention, you may perform calcination by heating the wound body provided with the 1st and 2nd electrode to at least 175 degreeC.

  The inventors of the present invention have found from the experimental results described below that the decrease in capacitance can be effectively suppressed within a wider temperature range by heating the wound body to 175 ° C. Therefore, by heating the wound body to at least 175 ° C., the situation in which the capacitance of the wound film capacitor provided with the wound body after the heat treatment decreases as the temperature rises is effectively suppressed in a higher temperature range. In addition, the capacitance can be maintained regardless of the temperature.

  In the method for manufacturing a wound film capacitor according to the present invention, at least one of the conductive layers may be formed of an Ag alloy.

  According to the results of experiments conducted by the present inventors, when the predetermined heat treatment (calcination) is performed on a wound body in which at least one conductive layer is formed of an Ag alloy, the capacitance decreases. The suppressed results are clearly shown. Therefore, if the above-mentioned calcining is performed on a wound body having a conductive layer formed of an Ag alloy, extremely high temperature environment characteristics (in the high temperature range) combined with the heat resistance inherent in the Ag alloy. Resistance).

  In the method for manufacturing a wound film capacitor according to the present invention, at least one of the first and second insulating films may be a glass film.

  Since glass is a material in which oxygen vacancies are less likely to occur than other insulating materials, the temperature dependence of the dielectric constant can be reduced without reducing the dielectric constant. Therefore, by configuring the capacitor with a wound body in the form of a roll of a film made of glass and a conductive layer, while increasing the capacitance per unit volume of the capacitor, due to temperature changes, The situation where the circuit does not operate properly can be effectively prevented. Therefore, it is possible to manufacture a capacitor that is excellent in high temperature environmental characteristics and can store a large amount of energy. In addition, the wound film capacitor has a conductive layer that is densely wound into a roll together with an insulating film, and electrodes are formed on both sides in the width direction. Therefore, the inside of the capacitor is usually exposed to oxygen in the atmosphere. Although it is a difficult environment, it is particularly preferable to use a glass film as the insulating film, because many portions in the non-oxidized state remain in the conductive layer even after calcining because of its gas barrier properties and adhesion.

  In this case, in the method for manufacturing a wound film capacitor according to the present invention, the relative dielectric constant of the glass film may be set to 5.0 or more. The relative dielectric constant here refers to a value measured by a method based on ASTM D150 at a temperature of 25 ° C.

Further, in the method for manufacturing the wound-type film capacitor in accordance with the present invention, the glass film, in _{mass%, SiO 2: 20~70%,} Al 2 O 3: 0~20%, B 2 O 3: 0~ The glass composition may contain 17%, MgO: 0 to 10%, CaO: 0 to 15%, SrO: 0 to 15%, BaO: 0 to 40%.

  By setting the glass composition in this manner, devitrification is less likely to occur at the time of molding, so that an insulating film (glass film) having a large width direction dimension and a long direction dimension can be easily formed. Therefore, as a result, it is possible to efficiently manufacture a capacitor capable of storing a large amount of energy.

  In the method for manufacturing a wound film capacitor according to the above description, the first and second conductive layers, the first and second insulating films, the first conductive layer, and the first insulating film A laminated body forming step of forming a laminated body of insulating films by overlapping the second conductive layer and the second insulating film in this order, and forming a wound body by winding the laminated body around the core to form a wound body A first electrode is formed on one side in the width direction of the wound body by applying and solidifying a paste-like conductive material on both sides in the width direction of the wound body, and the width direction of the wound body An electrode forming step of forming a second electrode on the other side may be further included.

  Thus, a winding body can be easily produced by forming a winding body by winding up a laminated body using a core. In addition, by applying and solidifying a paste-like conductive material to form an electrode on the wound body, not only the width direction end face (side end face) of the corresponding conductive layer but also the width direction end including the end face An electrode can be formed so as to cover the part. As a result, even if the side end surfaces of the conductive layer are not exactly aligned with the winding, the electrodes corresponding to the respective conductive layers can be brought into contact with each other without leakage and stable energization can be achieved. .

  Moreover, the solution of the above-mentioned problem is also solved by the wound film capacitor according to the present invention. That is, in this capacitor, the first and second conductive layers and the first and second insulating films are the first conductive layer, the first insulating film, the second conductive layer, and the second insulating film. The wound body is in the form of being wound in a roll shape in the state of overlapping with each other, and is provided on one side in the width direction of the wound body, in contact with the first conductive layer and away from the second conductive layer A first electrode provided on the other side in the width direction of the wound body, and a second electrode in contact with the second conductive layer and separated from the first conductive layer. At least one of the conductive layers is a wound film capacitor formed of metal, characterized in that at least one of the conductive layers is oxidized and the rest is in a non-oxidized state. Attached.

  Thus, if it is a winding type film capacitor provided with the winding body in which a part of conductive layer was oxidized, the fall of the electrostatic capacity accompanying a temperature rise will be suppressed or maintained. Therefore, it is possible to provide a wound film capacitor that further improves the high-temperature environmental characteristics related to the capacitance and has improved reliability and practicality. This wound film capacitor can be produced, for example, by providing an electrode on a wound body having the conductive layer and then calcining.

  As described above, according to the present invention, it is possible to provide a wound film capacitor with further improved high-temperature environmental characteristics based on new knowledge about the temperature dependence of the wound film capacitor. It becomes.

1 is a perspective view of a wound film capacitor according to a first embodiment of the present invention. It is a perspective view which shows the state which expanded a part of winding body shown in FIG. 1 virtually. It is sectional drawing of the capacitor | condenser shown in FIG. It is a disassembled perspective view of the laminated body of the insulating film which comprises the wound body shown in FIG. It is a flowchart of the manufacturing method of the winding type film capacitor which concerns on 1st embodiment of this invention. It is a perspective view of a laminated body. It is a perspective view of the core used for winding of a laminated body. It is a figure for demonstrating an example of the winding aspect of a laminated body, Comprising: The figure which looked at the state of winding start of a laminated body from the direction along the winding centerline, and its principal part enlarged view. It is a figure for demonstrating an example of the winding aspect of a laminated body, Comprising: The figure which looked at the state of winding end of a laminated body from the direction along the winding centerline, and its principal part enlarged view. It is a perspective view of the winding body of the state which rolled up the laminated body around the core and integrated with the core. It is a graph which shows the relationship between time and temperature about the heat processing with respect to the wound body provided with a pair of electrode. It is a perspective view which shows the state which expanded a part of winding body which concerns on 2nd embodiment of this invention virtually. It is a perspective view showing the state where a part of modification of the winding object concerning a second embodiment of the present invention was developed virtually. It is a figure for demonstrating an example of the winding aspect of the winding body which concerns on 3rd embodiment of this invention, Comprising: It is the figure which looked at the winding body in winding from the direction along the centerline. It is the figure which looked at the wound body which concerns on 4th embodiment of this invention from the direction along the centerline. It is the figure which looked at the winding body which concerns on 5th embodiment of this invention from the direction along the centerline. It is a graph which shows the measurement result of the electrostatic capacitance in frequency 120Hz. It is a graph which shows the measurement result of the electrostatic capacitance in frequency 1000Hz. It is a graph which shows the measurement result of the electrostatic capacitance in frequency 10000Hz.

  Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a perspective view of a wound film capacitor 1 according to the first embodiment of the present invention. The capacitor 1 includes a wound body 2 and a pair of electrodes 3 and 4 that are in contact with the wound body 2 in the width direction. Lead electrodes (not shown) are attached to the electrodes 3 and 4 so that a predetermined voltage can be applied between the electrodes 3 and 4. Hereinafter, the configuration of the wound body 2 will be mainly described.

  As shown in FIG. 2, the wound body 2 includes first and second conductive layers 5 and 6 and first and second insulating films 7 and 8, and these two conductive layers 5 and 6. 6 and the two insulating films 7 and 8 are stacked in the order of the first conductive layer 5, the first insulating film 7, the second conductive layer 6, and the second insulating film 8 in the form of a roll. Shape. In the present embodiment, the first and second conductive layers 5 and 6 are both metal films, and the first surface 7 a and the second surface are oriented in opposite directions in the thickness direction of the first insulating film 7. 7b, respectively. Thus, the two conductive layers 5 and 6 are both integrated with the first insulating film 7.

  Of the two insulating films 7 and 8, at least the first insulating film 7 may be a glass film. In the present embodiment, the two conductive layers 5 and 6 are integrated with the glass film (first insulating film 7). The details of the glass composition that can be used will be described later.

  The thickness t1 (see FIG. 2) of the glass film as the first insulating film 7 is set to 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less, and further 20 μm or less. It is suitably set in the order of 10 μm or less, 8 μm or less, 6 μm or less, 5 μm or less, 3 μm or less, and particularly preferably 1 μm or less. The smaller the thickness dimension t1 of the first insulating film 7, the larger the area per unit volume in the state in which the insulating film 7 is wound, so that a large amount of energy can be easily stored. Moreover, since the flexibility of the 1st insulating film 7 improves, so that the thickness dimension t1 is small, the minimum curvature radius (minimum winding diameter) of the said insulating film 7 can be made small to the level mentioned later.

  Moreover, as the 2nd insulating film 8, the product made from resin, paper, and glass can be used, for example, glass (namely, glass film) can be used conveniently among these. By using a glass film for the second insulating film 8 as well, although depending on the composition of the pair of electrodes 3 and 4, it is possible to exclude the so-called organic substance and form the wound body 2 only with the inorganic substance. Become. Therefore, the heat resistance of the wound film capacitor 1 can be easily increased. Here, when using a glass film for the 2nd insulating film 8, the thickness dimension t2 (refer FIG. 2) of the said glass film (2nd insulating film 8) is the glass film as the 1st insulating film 7, and Similarly, it is set to 50 μm or less, preferably set to 40 μm or less, more preferably set to 30 μm or less, more preferably 20 μm or less, 10 μm or less, 8 μm or less, 6 μm or less, 5 μm or less, 3 μm or less. And particularly preferably 1 μm or less. Of course, a resin film can also be used for the second insulating film 8. In this case, the resin film functions as an insulator and also functions as a buffer material. Therefore, it is possible to effectively avoid a situation in which the glass film is damaged when the both insulating films 7 and 8 are wound up.

  The first conductive layer 5 is in a direction opposite to the first side end face 5a and the first side end faces 5a and 6a directed to one side in the width direction of the wound body 2 (left side in FIG. 3). It has the 2nd side end surface 5b which faces the other (the right side in FIG. 3) of the width direction of the wound body 2. As shown in FIG. The second conductive layer 6 has a third side end face 6 a that faces one side in the width direction of the wound body 2 and a fourth side end face 6 b that faces the other side in the width direction of the wound body 2. . In the present embodiment, the second side end face 5b of the first conductive layer 5 is offset to one side in the width direction from the fourth side end face 6b of the second conductive layer 6, and the second side end face 5b is offset. The third side end face 6 a of the conductive layer 6 is offset to the other side in the width direction from the first side end face 5 a of the first conductive layer 5. Further, the first conductive layer 5 is offset in one direction, i.e., in the thickness direction of the first insulating film 7 (here, the first conductive layer 5 is formed) of the first surface 7a of the first surface 7a. The width direction dimension d1 of the region where the conductive layer 5 is not formed is set to, for example, 1 mm or more, preferably 2 mm or more, and more preferably 3 mm or more. Similarly, the second surface 7b of the second surface 7b is directed to the other in the thickness direction of the first insulating film 7 (here, the second conductive layer 6 is formed), which is an offset amount of the second conductive layer 6. The width direction dimension d2 of the region where the second conductive layer 6 is not formed is set to 1 mm or more, preferably 2 mm or more, and more preferably 3 mm or more. In this way, even if the laminated body 9 is displaced in the width direction due to the winding mode of the laminated body 9 (see FIGS. 4 and 5) described later, the first conductive layer 5 and the first conductive layer 5 The situation where the second electrode 4, the second conductive layer 6 and the first electrode 3 are electrically connected can be effectively avoided. Of course, although not shown in the drawings, the first surface 7a and the second surface 7b of the first insulating film 7 are equivalent to the conductive layers 5 and 6 in regions where the conductive layers 5 and 6 are not formed. An insulating film having a thickness dimension may be formed.

  Various materials can be used for the conductive layers 5 and 6. For example, from the viewpoint of cost and conductivity, one or more metals selected from the group consisting of Al, Pt, Ni, Cr, Cu, Ag, and an Ag alloy can be preferably used. Indicates better heat resistance than Ag alone. Further, from the viewpoint of the stability, denseness, and ion diffusion of the oxide film, Al is preferable, or various alloys such as a Ni—Cr alloy are also preferable. Further, as in the present embodiment, when the conductive layers 5 and 6 are formed as metal films on the surfaces 7a and 7b of the first insulating film 7 (glass film), known film forming means can be applied. is there. Of course, as long as at least one of the conductive layers 5 and 6 is formed of a metal, other configurations (including composition) are arbitrary, and a known conductive material other than metal, or metal and metal The other conductive layer may be formed with other conductive material.

  Moreover, in this embodiment, the width direction dimension w2 of the 2nd insulating film 8 in which the conductive layers 5 and 6 are not formed is larger than the width direction dimension w1 of the 1st insulating film 7, as shown in FIG. The first insulating film 7 is small and disposed so as to protrude from the second insulating film 8 to the outside in the width direction. In this way, it is possible to avoid the state in which the second insulating film 8 protrudes in the width direction of the wound body 2 rather than the conductive layers 5 and 6. Can be easily formed.

  The first electrode 3 serving as a positive electrode or a negative electrode is disposed on one side in the width direction of the wound body 2 (left side in FIG. 3). At this time, the first electrode 3 is electrically connected to the first conductive layer 5 adjacent in the thickness direction (vertical direction in FIG. 3) through the first insulating film 7 in the wound body 2. In contact with the first side end face 5a of the first conductive layer 5 and away from the third side end face 6a of the second conductive layer 6 so as to be insulated from the second conductive layer 6. Yes (not touching). The second electrode 4 is disposed on the other side in the width direction of the wound body 2 (on the right side in FIG. 3), is electrically connected to the second conductive layer 6, and is electrically connected to the first conductive layer. It is in contact with the fourth side end face 6b of the second conductive layer 6 and is separated (not in contact) with the second side end face 5b of the first conductive layer 5 so as to be insulated from the layer 5. .

  Various materials can be used for the electrodes 3 and 4. For example, from the viewpoint of cost and conductivity, one or more metals selected from the group consisting of Al, Pt, Ni, Cu, Ag, and an Ag alloy can be suitably used. It shows better heat resistance than the simple substance. For the electrodes 3 and 4, for example, a conductive paste containing the above metal powder (for example, a paste-like conductive material based on a resin and having a predetermined viscosity) is applied to both sides in the width direction of the wound body 2 and solidified. Can be formed. Note that a resin having high heat resistance (for example, an epoxy resin, a urethane resin, a silicon resin, or the like), an inorganic substance, or the like can be used for the paste. As a result, calcining can be performed at a higher temperature, so that the decrease due to the increase in the capacitance of the wound film capacitor can be effectively suppressed, or the capacitance can be maintained over a wide temperature range. It becomes possible to do. Also, the form that can be taken in this case is not particularly limited, and may be annular as shown in FIG. 1, or may be layered as shown in FIG. Of course, as shown in FIG. 1 and FIG. 3, it may be annular and layered.

  Further, the minimum winding diameter of the wound body 2 is set to, for example, 100 mm or less, preferably 80 mm or less, more preferably 75 mm or less, further 50 mm or less, 30 mm or less, 20 mm or less, 10 mm or less, 5 mm or less in this order. It is set suitably, and particularly preferably set to 3 mm or less. When the outer diameter dimension of the wound body 2 is constant, the smaller the minimum winding diameter, the larger the area per unit volume, which is suitable for applications that require storage of a large amount of energy.

  The longitudinal dimension L1 (see FIG. 4) of the first insulating film 7 is set to, for example, 0.05 m or more, preferably 0.5 m or more, more preferably 1 m or more. For example, 3 m or more, 5 m or more, 10 m or more, 30 m or more, 50 m or more, and 70 m or more are preferably set, and particularly preferably 100 m or more. Thus, by setting the size of the longitudinal direction dimension L1 of the first insulating film 7, it becomes possible to ensure a level of capacitance required for a current circuit, for example.

  Further, the width direction dimension w1 and the thickness dimension t1 are set such that the value obtained by dividing the width direction dimension w1 of the first insulating film 7 by the thickness dimension t1 is, for example, 1000 or more, and preferably 1200 or more. Preferably, the width direction dimension w1 and the thickness dimension t1 are suitably set in the order of 1600 or more, 1800 or more, 2000 or more, more preferably 1400 or more, and particularly preferably the width direction dimension w1 to be 2400 or more. A thickness dimension t1 is set. By setting both dimensions w1 and t1 so that the ratio between the width direction dimension w1 and the thickness dimension t1 is within the above range, for example, it is possible to ensure a level of capacitance required for a current circuit. It becomes.

  In addition, the relative dielectric constant of the first insulating film 7 is set to, for example, 5 or more, preferably 5.5 or more, more preferably 6 or more, and further 7 or more, 8 or more, 9 As described above, it is preferably set in the order of 10 or more, particularly preferably 11 or more. By using the first insulating film 7 (glass film) exhibiting a relative dielectric constant in the above-described range, it is possible to ensure a level of capacitance required for a current circuit, for example.

  The arithmetic average roughness Ra of the first surface 7a (second surface 7b) of the first insulating film 7 is set to, for example, 5 nm or less, preferably 3 nm or less, more preferably 1 nm or less, Furthermore, it is preferably set in the order of 0.8 nm or less, 0.4 nm or less, and 0.3 nm or less, and particularly preferably 0.2 nm or less. By setting the arithmetic average roughness Ra of the first surface 7a (second surface 7b) of the first insulating film 7 within the above range, the voltage that causes dielectric breakdown when a high voltage is applied is increased. be able to.

  The maximum height Rmax of the first surface 7a (second surface 7b) of the first insulating film 7 is set to, for example, 10 nm or less, preferably 5 nm or less, and more preferably 3 nm or less. The By setting the maximum height Rmax of the first surface 7a (second surface 7b) of the first insulating film 7 within the above range, the voltage causing dielectric breakdown when a high voltage is applied is increased. be able to. In addition, the maximum height Rmax here refers to the value measured by the method based on JIS B0601: 2001.

The glass composition of the first insulating film 7 is arbitrary. For example, in this embodiment, the glass composition is in mass%, for example, SiO ₂ : 20 to 70%, Al ₂ O ₃ : 0 to 20%, B ₂ O. ₃ : 0 to 17%, MgO: 0 to 10%, CaO: 0 to 15%, SrO: 0 to 15%, BaO: 0 to 40% are preferably contained.

  Of course, it is also possible to add components other than the above to the glass composition of the first insulating film 7 in a range of, for example, up to 20%, preferably up to 10%.

The liquid phase temperature of the first insulating film 7 is set to, for example, 1200 ° C. or less, preferably 1150 ° C. or less, more preferably 1090 ° C. or less, and further 1050 ° C. or less, 1030 ° C. or less. Is preferably set, particularly preferably 1000 ° C. or lower. If the liquid phase temperature of the first insulating film 7 is too high, the glass tends to be devitrified during molding, and it becomes difficult to improve the surface accuracy (surface roughness, etc.) of the first insulating film 7. is there. Further, the liquid phase viscosity of the first insulating film 7 is set to, for example, 10 ^3.5 dPa · s or more, preferably 10 ^4.0 dPa · s or more, more preferably 10 ^4.5 dPa · s or more, Preferably it is set to 10 ^4.8 dPa · s or more, particularly preferably 10 ^5.0 dPa · s or more. This is because if the liquid phase viscosity of the first insulating film 7 is too low, devitrification of the glass tends to occur during molding, and it becomes difficult to increase the surface accuracy of the first insulating film 7. Here, the liquid phase viscosity refers to a value obtained by measuring the viscosity of glass at the liquid phase temperature by a platinum ball pulling method. The liquid phase temperature passes through a standard sieve 30 mesh (about 500 μm), and the glass powder remaining in 50 mesh (about 300 μm) is put in a platinum boat and kept in a temperature gradient furnace for 24 hours to precipitate crystals. Refers to the value measured temperature.

For example, the density of the first insulating film 7 is set to 4.5 g / cm ³ or less, preferably set to 4.0 g / cm ³ or less, more preferably set to 3.6 g / cm ³ or less. For example, it is suitably set in the order of 3.3 g / cm ³ or less, 3.0 g / cm ³ or less, and 2.8 g / cm ³ or less, particularly preferably 2.5 g / cm ³ or less. The smaller the density, the easier it is to reduce the weight of the wound film capacitor 1. In addition, the density here refers to the value measured by the well-known Archimedes method.

The thermal expansion coefficient of the first insulating film 7 is set to, for example, 25 × 10 ^{−7 to} 120 × 10 ⁻⁷ / ° C., preferably set to 30 × 10 ^{−7 to} 120 × 10 ⁻⁷ / ° C., and more preferably. Is set to 40 × 10 ^{−7 to} 110 × 10 ⁻⁷ / ° C., more preferably 60 × 10 ^{−7 to} 100 × 10 ⁻⁷ / ° C., and particularly preferably 70 × 10 ^{−7 to} 95 × 10 ^-7 / ℃ is set. If the coefficient of thermal expansion of the first insulating film 7 is set in the above range, the coefficient of thermal expansion of the first insulating film 7 and the surfaces 7a and 7b of the first insulating film 7 are formed by film formation or the like. Since the thermal expansion coefficients of the conductive layers 5 and 6 can be matched (approached), deformation of the conductive layers 5 and 6 such as warpage can be prevented. In addition, a thermal expansion coefficient here refers to the average value measured with the dilatometer in the range of 30-380 degreeC.

The temperature at 10 ^2.5 dPa · s of the first insulating film 7 is set to, for example, 1550 ° C. or less, preferably 1450 ° C. or less, more preferably 1350 ° C. or less, and further 1250 ° C. or less. It is suitably set in the order of 1200 ° C. or lower and 1170 ° C. or lower, particularly preferably 1150 ° C. or lower. The lower the temperature of the first insulating film 7 at 10 ^2.5 dPa · s, the easier it is to melt the glass at a low temperature, so the manufacturing cost of the glass film can be reduced. Here, the temperature at 10 ^2.5 dPa · s indicates a value measured by a platinum ball pulling method.

  At least a part of the surface 7a (7b) of the first insulating film 7 may be in an unpolished state. Moreover, in that case, it is preferable that all of the first surface 7a and the second surface 7b directed in opposite directions are unpolished. Although the theoretical strength of glass is very high, in fact, it often breaks at much lower stresses than the theoretical strength. This is because a small defect called Griffith flow is generated on the surface of the glass in a post-molding process such as a polishing process. Therefore, if the first surface 7a (second surface 7b) of the first insulating film 7 which is a glass film is unpolished, in other words, the first surface 7a (second surface 7b) is formed on the molding surface. If so, the mechanical strength of the glass can be brought close to the original strength, thereby preventing the glass film from being broken as much as possible. Specifically, a first insulating film having a first surface 7a (second surface 7b) which is unpolished and has excellent surface accuracy by molding a glass film by a redraw method or an overflow downdraw method which will be described later. 7 can be obtained.

  As a forming means of the first insulating film 7, for example, a redraw method can be adopted. According to this method, the thickness dimension t1 of the first insulating film 7 can be easily reduced. Further, the surface quality of the first insulating film 7 can be improved. Furthermore, each side end surface 7c, 7d (refer FIG. 3) of the 1st insulating film 7 is made into a shaping | molding surface (it may call a fire-making surface), and the 1st insulating film 7 has each side end surface 7c, 7d has the advantage that it is difficult to break. The redraw method is a method in which a molded glass is heated again to a temperature near the softening point and stretched to form the glass into a predetermined shape (in the case of this embodiment, a long film). Say.

  Of course, as a means for forming the first insulating film 7, glass film forming means other than redraw, such as an overflow down draw method or a slot down draw method, may be employed. The overflow down-draw method is a forming method called fusion method, in which molten glass overflows from both sides of the heat-resistant bowl-like structure, and the overflowing molten glass is joined at the lower end of the bowl-like structure. However, this is a method of obtaining glass having a predetermined shape (long glass film in the case of the present embodiment) by stretching downward. Surface quality can also be improved by forming a glass film by the overflow downdraw method.

  When the second insulating film 8 is a glass film, it is possible to make at least one of the glass composition, physical properties, shape, surface properties, dimensions, molding conditions, and the like of the first insulating film 7 described above the same. . Of course, if there is no particular problem in terms of cost and productivity, glass films having different glass compositions, physical properties, shapes, surface properties, dimensions, molding conditions, and the like may be used for the second insulating film 8. .

  As mentioned above, although the material (glass composition) of both the insulating films 7 and 8 was described, as long as it can wind up without generating a crack, not only the glass composition mentioned above but various materials are also employable. It is. Specific examples include alkali-free glass, soda glass, and alkali-containing glass.

  The thickness dimension t2 of the second insulating film 8 is arbitrary. For example, when the second insulating film 8 is a glass film, the second insulating film 8 has a thickness dimension t1 with respect to the thickness dimension t1 of the first insulating film 7. The thickness dimension t2 is set so that the relative thickness dimension (the value obtained by dividing the thickness dimension t2 of the second insulating film 8 by the thickness dimension t1 of the first insulating film 7) is, for example, 0.3 or more, preferably 0. The thickness dimension t2 is suitably set in the order of 0.6 or more, 0.7 or more, 0.8 or more, more preferably 0.5 or more, more preferably 0.5 or more, and particularly preferably The thickness dimension t2 is set so as to be 0.9 or more. On the other hand, from the viewpoint of the upper limit value, the thickness dimension t2 of the second insulating film 8 is set so that the ratio of the thickness dimensions t1 and t2 is, for example, 3.0 or less, preferably 2.5 or less. More preferably, the thickness dimension t2 is suitably set in the order of 1.8 or less, 1.5 or less, 1.3 or less, 1.2 or less, 1.1 or less, more preferably 2.0 or less. Particularly preferably, the thickness dimension t2 is set to be 1.05 or less.

  In the present embodiment, the wound body 2 passes through the center of the wound body 2 in the direction along the width direction of the wound body 2, that is, in the direction along the center line X <b> 1 of the wound body 2 in FIG. 2. A through hole 10 is provided. The through hole 10 penetrates not only the wound body 2 but also the electrodes 3 and 4 attached to both sides in the width direction. Therefore, as shown in FIG. 1, the through hole 10 penetrates the wound film capacitor 1 in the direction along the center line at the center of the wound film capacitor 1. In this case, the center line of the wound film capacitor 1 is equal to the center line X1 of the wound body 2 (see FIGS. 1 and 2). Moreover, in this embodiment, since the internal peripheral surface of the through-hole 10 is comprised by the 2nd surface 8b of the 2nd insulating film 8 (refer FIG. 3), the internal diameter dimension D of the through-hole 10 in this case Is substantially equal to the minimum winding diameter of the insulating film 8 described above.

  Next, an example of a method for manufacturing the wound film capacitor 1 having the above-described configuration will be described mainly based on FIGS.

  As shown in FIG. 5, the winding type film capacitor 1 is manufactured by a laminated body forming step S <b> 1 for forming the laminated body 9, a wound body forming step S <b> 2 for forming the wound body 2, and a wound body. A through hole forming step S3 for forming a through hole 10 in 2; an electrode forming step S4 for providing a pair of positive and negative electrodes 3 and 4 on both sides in the width direction of the wound body 2; and a wound body provided with the electrodes 3 and 4 2 includes a calcination step S5 for performing calcination.

(S1) Laminate Forming Step In this step, the long laminate 9 is formed by alternately stacking the two insulating films 7 and 8 and the two conductive layers 5 and 6. In the present embodiment, as shown in FIG. 4, a first insulation in which metal films as first and second conductive layers 5 and 6 are integrally formed on the first and second surfaces 7a and 7b, respectively. The film 7 is placed on the second insulating film 8, and the first conductive layer 5, the first insulating film 7, the second conductive layer 6, and the second insulating film 8 are laminated in this order. A laminated body is formed (see FIG. 6). In FIG. 4, the longitudinal dimension L1 of the first insulating film 7 and the longitudinal dimension L2 of the second insulating film 8 are the same length. The lengths L1 and L2 can be appropriately adjusted by, for example, direct adhesion between the insulating films 8).

  At this time, the second surface 7b of the first insulating film 7 and the third surface 8a of the second insulating film 8 or the fourth surface 8b of the second insulating film 7 and the first insulating film Insulating films 7 and 8 are both glass films, and the surface roughness is set to a predetermined size so that the first surface 7 is in direct contact with no adhesive or the like. It is also possible to take a form in which the end in the longitudinal direction of the insulating film 7 protrudes from the conductive layers 5 and 6 in the longitudinal direction (see FIG. 4). Here, when the surface roughness is expressed by the arithmetic average roughness Ra, the arithmetic average roughness Ra of the second surface 7b and the third surface 8a (the first surface 7a and the fourth surface 8b) that are in close contact with each other. Are preferably set to 2.0 nm or less. By setting the arithmetic average roughness Ra of each surface 7b, 8a (7a, 8b) within the above-described range, the two insulating films 7, 8 are wound in a roll shape while being fixed to each other without positional displacement. It is possible to maintain the formed shape (maintain the shape of the wound body 2). Of course, from the viewpoint of improving adhesion, it is preferably 1.0 nm or less, more preferably 0.8 nm or less, 0.4 nm or less, and 0.3 nm or less in order, and 0.2 nm or less. Particularly preferred.

(S2) Winding body formation process In this process, the winding body 2 is formed by winding the laminated body 9 formed by process S1 around the core 11 shown, for example in FIG. Here, any form, structure, and material can be adopted as the core 11. In this embodiment, the core 11 having a cylindrical shape is used. Winding of the laminate 9 using the core 11 is performed as follows, for example. First, as shown in FIG. 8, one end portion 9 a in the longitudinal direction of the laminate 9 that is the end portion on the winding start side is brought into close contact with the outer peripheral surface (winding surface) of the core 11, and the shaft fitting hole 11 a of the core 11 is fitted. A rotary drive shaft (not shown) such as a motor is fitted, and the rotary drive shaft is rotationally driven to start winding the laminate 9. At this time, as shown in FIG. 8, the second surface 7 b of the first insulating film 7 and the third surface 8 a of the second insulating film 8 are directly connected to each other at one longitudinal end 9 a of the laminate 9. After forming the contact | adhered area | region, it winds up so that the two insulating films 7 and 8 and the two conductive layers 5 and 6 may overlap | superpose in the order shown in FIG. In addition, in order to maintain more reliably the form at the time of winding of the insulating films 7 and 8 after removing the core 11, the 1st surface 7a used as the outer surface of the 1st insulating film 7, and 2nd Projection dimension of the first insulating film 7 from the conductive layers 5 and 6 toward the one end portion 9a in the longitudinal direction so that the fourth surface 8b which is the inner surface of the insulating film 8 is in direct contact with the fourth surface 8b. It is also possible to set p1 (see FIG. 4). That is, both the insulating films 7 and 8 are wound around the core 11 one or more times in a state where the second surface 7b of the first insulating film 7 and the third surface 8a of the second insulating film 8 are in direct contact with each other. It is also possible to set the protruding dimension p1 of the first insulating film 7 from the conductive layers 5 and 6 to such an extent that it can be taken.

  Further, as described above, when the two insulating films 7 and 8 are wound in a state of being overlapped with each other, conditions such as a winding speed, a winding angle, and a winding direction of each insulating film 7 and 8 are set. It should be managed appropriately. By appropriately managing the winding condition in this manner, sliding contact between the insulating films 7 and 8 and undue stress concentration can be avoided, and the breakage probability of the glass film can be reduced.

  In this way, the laminate 9 is wound around the core 11, and as shown in FIG. 9, for example, the other end 9b in the longitudinal direction, which is the end portion on the winding end side of the laminate 9, is positioned immediately inside thereof. By fixing to the outer surface (third surface 8a) of the second insulating film 8 to be formed, the wound body 2 (see FIG. 10) integrally having the core 11 is formed. At this time, the fixing means of the first insulating film 7 is arbitrary, but it is also possible to employ a fixing means using direct contact with the second insulating film 8 as in the case of starting winding. That is, as shown in FIG. 9, at the other end 9 b in the longitudinal direction of the laminated body 9, the inner surface of the first insulating film 7 (second surface 7 b) and the outer surface of the second insulating film 8. From the conductive layers 5 and 6 of the first insulating film 7 such that both the insulating films 7 and 8 can be wound around the core 11 one or more times in a state in which the surface (the third surface 8a) is in direct contact. It is also possible to set the protrusion dimension p2 (see FIG. 4). By doing in this way, the inner surface (second surface 7b) of the first insulating film 7 located on the outermost radial direction and the outer surface (third surface 8a) of the second insulating film 8 Not only directly but also the inner surface (fourth surface 8b) of the second insulating film 8 and the outer surface (first surface 7a) of the first insulating film 7 in the previous circumference. And are in direct contact. Thereby, it is possible to form the wound body 2 formed by winding the laminated body 9 and firmly fix both the insulating films 7 and 8 at the end of the laminated body 9 on the winding end side.

(S3) Through-hole forming step After forming the wound body 2 having the core 11 integrally as described above, the core 11 is removed from the wound body 2, whereby the winding body 2 is wound around the center of the wound body 2. A through hole 10 that penetrates the body 2 in the width direction is formed. Specifically, the core 11 is removed from the wound body 2 by grasping and pulling the exposed portion of the core 11 from the state shown in FIG. Thereby, the wound body 2 provided with the through hole 10 in the center is obtained. In the wound body 2 formed at this time, although not shown, the first and second conductive layers 5 and 6 and the first and second insulating films 7 and 8 are both spiral. The first conductive layer 5, the first insulating film 7, the second conductive layer 6, and the second insulating film 8 are repeatedly positioned in this order from the outside in the radial direction.

(S4) Electrode formation process After forming the wound body 2 in this way, both positive and negative electrodes 3 and 4 are formed on both sides of the wound body 2 in the width direction. At this time, the first electrode 3 located on one side in the width direction of the wound body 2 is in contact with the first side end face 5a of the first conductive layer 5 as shown in FIG. The conductive layer 6 is formed so as not to contact the third side end surface 6a. The second electrode 4 located on the other side in the width direction of the wound body 2 is in contact with the fourth side end face 6 b of the second conductive layer 6 and the second side end face of the first conductive layer 5. It is formed so as not to contact 5b. As a result, both the positive and negative electrodes 3 and 4 are formed so as to cover the end in the width direction of the wound body 2 and are electrically connected only to the corresponding conductive layers 5 and 6, as shown in FIG. The wound body 2 in the form, that is, in a state in which the pair of electrodes 3 and 4 are provided on both sides in the width direction is obtained.

  In addition, although the formation means of the electrodes 3 and 4 is arbitrary, from a viewpoint which implement | achieves the electrical connection mentioned above easily, the electrically conductive paste containing the metal powder mentioned above is apply | coated to the width direction both sides of the wound body 2 However, it is preferable to form by solidifying. That is, it is difficult to accurately align the positions of the side end faces 7c, 7d, 8c, and 8d (see FIG. 3) in the width direction because of the property of winding the two insulating films 7 and 8 in a spiral shape. Variations in position are unavoidable. Therefore, for example, when the electrodes 3 and 4 are plate-shaped, it is extremely difficult to make them contact with the entire area of the side end faces 5a, 5b, 6a and 6b of the conductive layers 5 and 6. On the other hand, in the case of a paste-like conductive material, it adheres following the position of each side end face 5a, 5b, 6a, 6b. The electrodes 3 and 4 are in close contact with each other. Moreover, when it becomes a low-viscosity liquid when supplied, such as solder, it may flow between the insulating films 7 and 8 and adhere to the conductive layer 5 (6) on the side to be insulated. On the other hand, if it is a paste-like conductive material, the situation of flowing between the insulating films 7 and 8 can be avoided, so that it is necessary to avoid adhesion to the conductive layer 5 (6) on the side to be insulated. It is possible to obtain electrical connection only with the conductive layer 6 (5) on the side.

(S5) Calcination step In this step, a predetermined heat treatment (calcination) is performed on the wound body 2 obtained in step S4. This heat treatment is performed by heating the metal (for example, an Ag alloy) forming the first and second conductive layers 5 and 6 to a temperature at which oxidation starts in the atmosphere or higher. In the present embodiment, for example, the winding body 2 is put into a heating furnace (such as a drying furnace), and the temperature is raised and kept warm from the room temperature so that the heat history shown in FIG. (After that, it was kept warm). When tracing the thermal history shown in FIG. 11, the temperature is increased from room temperature to 50 ° C., 75 ° C., 100 ° C., 125 ° C., 150 ° C., 175 ° C. and 25 ° C., and the temperature is kept for 10 minutes on average. 2 was subjected to predetermined heat treatment. After the heat treatment, the wound body 2 was removed from the heating furnace and cooled to room temperature. Thereby, the wound film capacitor 1 is completed. At this time, discoloration due to oxidation can be visually recognized through the insulating film in a part (for example, end portions in the width direction) of the first and second conductive layers 5 and 6 constituting the wound body 2.

  As described above, in the method for manufacturing the wound film capacitor 1 according to the present invention, the two conductive layers 5 and 6 and the two insulating films 7 and 8 are alternately overlapped and wound into a roll. After providing the pair of electrodes 3 and 4 on the wound body 2, the wound body 2 was calcined. Thus, by performing predetermined heat processing to the wound body 2, the fall of the electrostatic capacitance accompanying a temperature rise can be suppressed or maintained. Therefore, it is possible to provide a wound film capacitor 1 that further improves the high-temperature environment characteristics related to the capacitance and has improved reliability and practicality.

  In the present embodiment, at least one of the conductive layers 5 (6) is made of an Ag alloy, and the wound body 2 is calcined by heating to 125 ° C. or higher. In a wide temperature range, the situation in which the capacitance of the wound film capacitor 1 provided with the wound body 2 after heat treatment decreases with increasing temperature is effectively suppressed, or the capacitance of the wound film capacitor 1 does not depend on the temperature. The size can be maintained.

  As mentioned above, although 1st embodiment of this invention was described, the winding type film capacitor 1 which concerns on this invention, or its manufacturing method is not limited to the said embodiment, Various forms are within the scope of this invention. It is possible to take

  For example, in the above-described embodiment, the case where the heat history of raising the temperature from room temperature to 175 ° C. is illustrated as the calcining, but it is of course possible to perform heat treatment (calcining) with other heat history. is there. For example, although illustration is omitted, the wound body 2 obtained in step S4 may follow a thermal history of raising the temperature from room temperature to a maximum of 25 ° C., and may be 30 ° C., 40 ° C., 50 ° C., respectively. The thermal history of raising the temperature to 75 ° C. or 100 ° C. may be traced. In short, the maximum temperature at the time of calcination is arbitrary as long as it is higher than the temperature at which the oxidation of the metal forming the conductive layers 5 and 6 substantially starts.

  When calcining the wound body 2, the higher the temperature at the time of calcining, the more effectively the decrease in capacitance is suppressed, or the required capacitance is within a wide temperature range regardless of the temperature. Can be maintained. On the other hand, when the temperature at the time of calcination is too high, the constituent elements of the wound film capacitor 1 are deformed, and the performance as the wound film capacitor 1 may be deteriorated. Therefore, in consideration of the heat resistance of each element constituting the wound film capacitor 1, from the viewpoint of suppressing performance degradation of the wound film capacitor 1 due to the deformation as much as possible, the first and second It is preferable to carry out calcination by heating the wound body 2 provided with the electrodes 3 and 4 at a temperature lower than the softening deformation temperature of each element constituting the wound film capacitor 1.

  The time for calcining is not particularly limited, but from the viewpoint of stabilizing the performance of the wound film capacitor 1, the time (total time) from the start to the end of calcining is set to 1 minute or more. It is preferable to be set to 2 minutes or more, 3 minutes or more, 5 minutes or more, 7 minutes or more, and 10 minutes or more. In short, it is preferable to heat for a sufficient time until the oxidation of the conductive layers 5 and 6 of the wound film capacitor 1 reaches a certain steady state at the calcining temperature (the highest temperature during calcining). . By doing so, when using the wound film capacitor 1 in a temperature environment at least lower than the calcining temperature, it is possible to suppress or maintain a decrease in capacitance due to temperature rise. Therefore, it is possible to provide a wound film capacitor 1 that further improves the high-temperature environment characteristics related to the capacitance and has improved reliability and practicality.

  On the other hand, it is preferable to set the time for performing the calcination so as not to cause substantial deterioration of the wound film capacitor 1. For example, when the calcining temperature (maximum temperature) is high, the risk of causing deterioration of the wound film capacitor 1 is increased by performing calcining for a long time. Even when the calcining temperature is not so high, the heat treatment more than necessary for a long time increases the manufacturing cost of the wound film capacitor 1 and may cause a decrease in productivity. For the above reasons, the total calcination time is preferably set within 6 hours at most, and more preferably within 3 hours, within 2 hours, within 1 hour. Although it depends on the required characteristics, if the constant control of the capacitance is not strictly used, that is, if it is a normal use, it should be set within 1 hour, preferably within 30 minutes, more preferably 10 minutes. It is better to set the total calcining time within.

  In the above embodiment, the first and second conductive layers 5 and 6 are both metal films, and the first and second metal films (conductive layers 5 and 6) are both of the first insulating film 7. Although the case where it formed into a film on the 1st and 2nd surface 7a and 7b, respectively was illustrated, of course, it is also possible to take forms other than this. FIG. 12 is a perspective view of the wound body 2 according to an example (second embodiment of the present invention), and the first and second conductive layers 5 and 6 and the first and second insulating films 7, A state where 8 is virtually expanded is indicated by a two-dot chain line. As shown in this figure, in the wound body 2 according to this embodiment, the first and second conductive layers 5 and 6 are both metal films, and the first metal film (first conductive layer 5) is The first insulating film 7 is formed on the first surface (here, the outer surface) 7 a, and the second metal film (second conductive layer 6) is formed on the third insulating film 8. A film is formed on the surface (here, the outer surface) 8a. In this case, for example, as shown in FIG. 12, the first conductive layer 5, the first insulating film 7, the second conductive layer 6, and the second insulating film 8 in this order from the outside in the radial direction of the wound body 2. It is possible to take the form which wound two insulating films 7 and 8 in roll shape so that it may be arrange | positioned. Further, from the viewpoint of increasing the degree of freedom at the end of winding, as shown in FIG. 13, the first insulating film 7, the first conductive layer 5, the second insulating film 8, from the radially outer side of the wound body 2, It is also possible to take a form in which two insulating films 7 and 8 are wound into a roll shape so as to be arranged in the order of the second conductive layer 6. Of course, in this case, as shown in FIG. 3, the first conductive layer 5 and the second conductive layer 6 are offset in different directions in the width direction. Or although illustration is abbreviate | omitted, both the 1st and 2nd conductive layers 5 and 6 are made into a metal film, these 1st and 2nd metal films and the 1st and 2nd insulating films 7 and 8 are made into 1st. One metal film, the first insulating film 7, the second metal film, and the second insulating film 8 may be overlapped in this order and wound into a roll shape.

  Moreover, regarding the wound body forming step S2, for example, as shown in FIG. 14, the first insulating film 7 and the second insulating film 8 that are wound in a roll shape are drawn out so as to overlap each other, The wound body 2 may be formed by winding around the core 11 (third embodiment of the present invention). In this case, the formation process S1 of the laminated body 9 and the formation process S2 of the wound body 2 are performed simultaneously. In this case, although illustration is omitted, it is preferable to start winding from the second insulating film 8 and finish winding with the second insulating film 8.

  In this embodiment, the roll body 20 of the first insulating film 7 and the roll body 21 of the second insulating film 8 are arranged on the same side (both left sides in FIG. 14) with respect to the core 11. Of course, the roll body 20 of the first insulating film 7 and the roll body 21 of the second insulating film 8 are arranged on different sides with respect to the core 11 (FIG. 14). In other words, the roll body 20 may be provided on one of the left and right sides of the core 11 and the roll body 21 may be provided on the other side, and the core 11 may be drawn out. Further, with respect to the drawing position around the core 11, it is not always necessary to pull out the both insulating films 7 and 8 at the same circumferential position. For example, although not shown, each is directed toward a position shifted by 180 ° in the circumferential direction. The insulating films 7 and 8 may be pulled out.

  Moreover, in the above description, the winding body 2 of the winding type film capacitor 1 is exemplified as one in which the two insulating films 7 and 8 are wound in a true cylindrical shape (see FIG. 9 and the like). Of course, other shapes may be used. For example, as shown in FIGS. 15 and 16, when viewed from the direction along the center line, the wound body 22 (fourth embodiment of the present invention) having an elliptical shape or a flat shape including a straight portion is formed. As long as the two insulating films 7 and 8 are wound into a roll shape such as the wound body 23 (fifth embodiment of the present invention), various forms can be taken.

  Moreover, in the above description, the winding body 2 which has the core 11 as a center is formed by winding the laminated body 9 around the core 11 (see FIG. 7) (see FIG. 10), and then the core 11 The case where the wound type film capacitor 1 in which the through hole 10 is finally formed at the center of the wound body 2 is manufactured by removing the wire from the wound body 2 is illustrated. Alternatively, the wound film capacitor 1 as a finished product may be manufactured in a state where it is left. In that case, by providing a pair of electrodes 3 and 4 on both sides in the width direction of the wound body 2 from the state shown in FIG. 10, a wound film capacitor (not shown) integrally having the core 11 can be obtained. It becomes possible.

  Hereinafter, the operation and effect of the present invention will be described based on examples.

<Production of glass plate>
First, a glass plate common to Example 1 and Comparative Example 1 was produced. More specifically, the glass composition is in mass%, SiO ₂ : 60%, Al ₂ O ₃ : 16%, B ₂ O ₃ : 10%, MgO: 1%, CaO: 8%, SrO: 4.5% , BaO: 0.3%, SnO ₂ : 0.2% After preparing one kind of glass raw material, the obtained glass batch was supplied to a glass melting furnace and melted at 1500 to 1600 ° C. . Next, after pouring the obtained molten glass on a carbon plate and forming it into a flat plate shape, a predetermined glass plate is obtained by performing a slow cooling process over 10 hours from the strain point to room temperature. It was. The density of this glass plate is 2.46 g / cm ³ , the strain point is 654 ° C., the annealing point is 709 ° C., the softening point is 944 ° C., and the high temperature viscosity is 10 ^4.0 dPa · s at 1268 ° C. and 10 ^3.0 dPa · s. 1428 ° C., 1532 ° C. at 10 ^2.5 dPa · s, the thermal expansion coefficient of 38 × 10 ^-7 / ℃, liquidus temperature 1084 ° C., liquidus viscosity 10 ^5.3 dPa · s, dielectric constant 5.3 met It was.

  The density was measured by a well-known Archimedes method.

  About a strain point and a slow cooling point, it measured by the method based on ASTMC336-71.

  The softening point was measured by a method based on ASTM C338-93.

The high temperature ^{viscosity, 10 4.0 dPa · s, 10} 3.0 dPa · s, and the temperature at 10 ^2.5 dPa · s, was measured by a platinum ball pulling method.

  About the thermal expansion coefficient, it measured with the dilatometer in the range of 30-380 degreeC.

  As for the liquidus temperature, the glass powder that passes through a standard sieve 30 mesh (about 500 μm) and remains in 50 mesh (about 300 μm) is placed in a platinum board and held in a temperature gradient furnace for 24 hours, and the temperature at which crystals precipitate. Was measured.

  Regarding the liquid phase viscosity, the viscosity of the glass at the liquid phase temperature was measured by a platinum ball pulling method.

  The relative dielectric constant was measured by a method based on ASTM D150.

<Production of capacitor>
After heating the glass plate to near the softening point, it is stretch-molded by a redraw method, and is a glass film (hereinafter referred to as a base glass film) having a longitudinal dimension of 50 m, a width dimension of 25 mm, and a thickness dimension of 10 μm. A glass film (hereinafter referred to as an intervening glass film) having a dimensional dimension of 50 m, a width dimension of 25 mm, and a thickness dimension of 9 μm was obtained. The material is the same for any glass film. The arithmetic average roughness Ra was both set to 0.2 nm.

  Next, with respect to one surface and the other surface (the first surface 7a and the second surface 7b of the first insulating film 7 referred to in the present invention) of the obtained base glass film, the thickness dimension is 45 nm. A metal film was formed by film formation. The metal was an Ag alloy. During film formation, an area from the second side end face (see FIG. 3 and paragraph 0056) to 3 mm of one surface was masked so that no Ag alloy film was formed on the masking portion. In addition, an area from the first side end face (see FIG. 3 and paragraph 0056) to 3 mm of the other surface was masked so that no Ag alloy film was formed on the masking portion. In this way, after the Ag alloy film was formed, the masking portion was removed.

  Subsequently, the base glass film and the intervening glass film are overlapped, and the overlapped one is formed in a columnar shape as shown in FIG. 7 and is wound around the outer peripheral surface of the core having an outer diameter of 30 mm. Formed. Thereafter, the core was removed from the wound body to form a through hole in the center of the wound body.

  After removing the core in this way, a pair of electrodes was formed by applying and solidifying a conductive paste on both sides of the wound body in the width direction. Specifically, the first side end face of the Ag alloy film formed on one surface of the base glass film is electrically connected, and the first Ag alloy film formed on the other surface is first connected. The entire side end face was not in contact with one electrode (not electrically connected). The second side end face of the Ag alloy film formed on the other surface of the base glass film is electrically connected, and the second side end face of the Ag alloy film formed on the one surface is electrically connected. Was not in contact with the other electrode (not electrically connected). Here, as the conductive paste, a conductive paste (specifically, CW2400 manufactured by ITW Chemtronics) in which Ag powder is blended with a base resin was used.

  Thus, after forming the wound body provided with a pair of electrodes, the electrostatic capacity of this wound body was measured with an impedance analyzer (Solartron 1260 type, applied voltage: 100 mV). Specifically, a wound body (winding film capacitor) in which a lead wire is attached to the electrode and made energized is put into a drying furnace, and the temperature is raised while raising the temperature with the thermal history shown in FIG. The capacitance at 50 ° C., 75 ° C., 100 ° C., 125 ° C., 150 ° C., and 175 ° C. was measured.

  Here, Comparative Example 1 is a case where after a pair of electrodes is provided on the wound body, the capacitance is measured by the above-described procedure without performing any heat treatment.

  On the other hand, after providing a pair of electrodes on the wound body, after performing heat treatment (calcination) with the thermal history shown in FIG. The capacity was measured. This case was referred to as Example 1 (first time). Further, after the measurement of the capacitance according to Example 1, the test piece according to Example 1 was once cooled to room temperature, and thereafter, the capacitance was measured again by the above-described procedure. This case was referred to as Example 1 (second time). In this example, since the heat history of calcining and the heat history at the time of measuring the capacitance are the same, the measurement of the capacitance with the above-described heat history for a single test piece is 3 in total. I went twice.

  Further, in this example, the above-described series of heat treatment and capacitance measurement were performed on the test piece three times in total. At this time, the capacitance was measured by changing the frequency. The implemented frequencies are three levels of 120 Hz, 1000 Hz, and 10000 Hz.

  In FIG. 17, the measurement result of the electrostatic capacitance of the comparative example 1 and Example 1 (the 1st time and the 2nd time) in frequency 120Hz is shown. Moreover, the measurement result of the electrostatic capacitance of the comparative example 1 and Example 1 (the 1st time and the 2nd time) in frequency 1000Hz is shown in FIG. FIG. 19 shows the measurement results of the capacitances of Comparative Example 1 and Example 1 (first time and second time) at a frequency of 10000 Hz. As shown in these figures, at any frequency, when no heat treatment was performed after providing a pair of electrodes on the wound body (Comparative Example 1), the temperature exceeded about 100 ° C. (125 At the time of ° C), there is a decrease in capacitance. On the other hand, after providing a pair of electrodes on the wound body and performing a predetermined heat treatment (calcination) (Example 1), after exceeding 100 ° C. at any frequency, No significant decrease in capacitance was observed, and the value was almost constant over the entire temperature range.

1 Winding type film capacitor 2, 22, 23 Winding body 3, 4 Electrode 5, 6 Conductive layer 7 First insulating film (glass film)
8 Second insulating film 9 Laminate 10 Through hole 11 Core 20, 21 Roll body S1 Laminate formation process S2 Winding body formation process S4 Electrode formation process S5 Pre-baking process

Claims (10)

The first and second conductive layers and the first and second insulating films are in the order of the first conductive layer, the first insulating film, the second conductive layer, and the second insulating film. A wound body in the form of a roll wound in an overlapping state;
A first electrode provided on one side in the width direction of the wound body, in contact with the first conductive layer and separated from the second conductive layer;
A second electrode provided on the other side in the width direction of the wound body, in contact with the second conductive layer and separated from the first conductive layer;
At least one of the first and second conductive layers is a method for manufacturing a wound film capacitor formed of metal,
A method for manufacturing a wound film capacitor, wherein calcining is performed after the first electrode and the second electrode are provided on the wound body.   The calcining is performed by heating the wound body provided with the first and second electrodes from room temperature to a temperature at which oxidation of the metal forming the first and second conductive layers starts together. The manufacturing method of the wound type film capacitor of Claim 1 performed.   The method of manufacturing a wound film capacitor according to claim 1 or 2, wherein the calcining is performed by heating the wound body provided with the first and second electrodes to 125 ° C or higher.   The wound type film according to any one of claims 1 to 3, wherein the calcining is performed by heating the wound body provided with the first and second electrodes to at least 175 ° C. Capacitor manufacturing method.   The method for producing a wound film capacitor according to any one of claims 1 to 4, wherein the at least one conductive layer is formed of an Ag alloy.   The method for manufacturing a wound film capacitor according to any one of claims 1 to 5, wherein at least one of the first and second insulating films is a glass film.   The method for manufacturing a wound film capacitor according to claim 6, wherein a relative dielectric constant of the at least one insulating film is set to 5.0 or more. Wherein at least one of the insulating film, in _{mass%, SiO 2: 20~70%,} Al 2 O 3: 0~20%, B 2 O 3: 0~17%, MgO: 0~10%, CaO: 0 The manufacturing method of the wound type film capacitor of Claim 6 or 7 which makes | forms the glass composition containing -15%, SrO: 0-15%, BaO: 0-40%. The first and second conductive layers, the first and second insulating films, the first conductive layer, the first insulating film, the second conductive layer, and the second insulating film. A laminated body forming step of forming a laminated body of the insulating films by superimposing in the order of
A wound body forming step of winding the laminate around a core to form the wound body;
By applying and solidifying a paste-like conductive material on both sides in the width direction of the wound body, the first electrode is formed on one side in the width direction of the wound body, and the width of the wound body The method for producing a wound film capacitor according to any one of claims 1 to 8, further comprising an electrode forming step of forming the second electrode on the other side in the direction. The first and second conductive layers and the first and second insulating films are in the order of the first conductive layer, the first insulating film, the second conductive layer, and the second insulating film. A wound body in the form of a roll wound in an overlapping state;
A first electrode provided on one side in the width direction of the wound body, in contact with the first conductive layer and separated from the second conductive layer;
A second electrode provided on the other side in the width direction of the wound body, in contact with the second conductive layer and separated from the first conductive layer;
At least one of the first and second conductive layers is a wound film capacitor formed of a metal,
A wound film capacitor in which a part of the at least one conductive layer is oxidized and the remaining part is in a non-oxidized state.

Images