JP4784464B2 - Metallized film capacitors - Google Patents

Description

  The present invention relates to a metallized film capacitor used in various electronic devices.

  With recent demands for improving the reliability of electronic devices, electronic components used in the electronic devices are also required to have high reliability and long life.

  In a metallized film capacitor, gas such as water vapor existing inside the capacitor penetrates into the metallized film capacitor element and degrades the dielectric film and the deposited metal film, resulting in deterioration of the capacitor characteristics. Yes.

  Therefore, in order to prevent this characteristic deterioration, an adsorbent that has a large number of pores such as silica gel and zeolite and can adsorb gas to the surface of the pores is applied to the core portion and the outer peripheral portion of the metallized film capacitor element. It is known to arrange (see Patent Document 1).

  That is, FIG. 5 is a schematic cross-sectional view of a metallized film capacitor containing an adsorbent in the core part and outer peripheral part of the metallized film capacitor element, and FIG. 6 is a perspective view of the metallized film capacitor element.

  In FIG. 5, reference numeral 13 denotes a metallized film capacitor. The metallized film capacitor 13 includes a metallized film capacitor element 14, a capacitor case 15 for sealingly housing the metallized film capacitor element 14, It consists of a terminal 16 that penetrates the upper surface of the capacitor case 15 and is connected to the metallized film capacitor element 14.

  The metallized film capacitor element 14 has a metallized film 17 composed of a dielectric film such as polypropylene and a vapor-deposited metal film formed on one side of the dielectric film, and is wound around the dielectric film. Thus, the capacitor is formed by facing the deposited metal film.

  Then, as shown in FIG. 6, by arranging an adsorbent on the core portion 18 or the outer peripheral portion 19 of the metallized film capacitor element 14, the gas such as water vapor existing inside the capacitor case 15 with this adsorbent. It is configured to adsorb.

  As another conventional technique, it is known that a similar adsorbent is contained in a filling resin (see Patent Document 2).

  That is, FIG. 7 is a schematic sectional view of a metallized film capacitor in which an adsorbent is contained in a filling resin. In FIG. 7, reference numeral 20 denotes a metallized film capacitor. The metallized film capacitor 20 includes a metallized film capacitor element 21, an internal terminal 25 connected to the metallized film capacitor element 21, and the metallized film capacitor. A capacitor case 22 for housing the element 21, a filling resin 23 for sealing the metallized film capacitor element 21, a sealing plate 24 for sealing the capacitor case 22, and the sealing plate 24 are penetrated. And an external terminal 26 for connection to the internal terminal 25.

Then, the adsorbent 27 is included in the filling resin 23 so that the adsorbent 27 can adsorb gas such as water vapor existing inside the capacitor case 22.
JP 2002-353064 A JP-A-1-93108

  In the conventional metallized film capacitor described above, the adsorbent adsorbs the gas existing inside the capacitor, and further gas that penetrates through the capacitor case and enters the inside, and gas that enters from the gap between the capacitor case and the sealing plate Adsorbed, the pores of the adsorbent were filled with the adsorbed gas in a short period of time, reaching the limit of adsorption capacity, and no more gas could be adsorbed. Then, the gas that could not be adsorbed enters the capacitor element over time, thereby deteriorating the characteristics of the capacitor, and it has been difficult to maintain the characteristics of the capacitor for a long period of time.

  In order to suppress the intrusion of gas from the outside, it is conceivable to use a metal capacitor case. However, if the capacitor case is made of metal, the gas barrier property and the sealing property can be improved, but the cost is high. In addition, there is a problem that it is difficult to reduce the weight because of its heavy weight.

  In order to recover the adsorption capacity of the adsorbent, it is conceivable to desorb (desorb) by heating the adsorbent to which the gas has been adsorbed. However, since the capacitor case is normally sealed, Even if desorbed, it cannot be released to the outside of the capacitor case, and is again adsorbed by the adsorbent.

  Furthermore, even if the adsorbent is heated, the pressure inside the capacitor case increases due to the desorbed gas inside the sealed capacitor case, and the capacitor may be deformed or the desorbed gas may become a metal. In some cases, it may be difficult to use at a high temperature at which the adsorbed gas is desorbed because the capacitor characteristics may be deteriorated by intruding into the fluorinated film capacitor element.

  The present invention provides a metallized film capacitor that can solve the above-mentioned problems with a very simple configuration, improve the reliability, and extend the life.

In order to solve the above-mentioned problems, the present invention is a metallized film capacitor mounted on a vehicle , comprising a dielectric film and a metallized film comprising a vapor-deposited metal film vapor-deposited on at least one side of the dielectric film; A metallized film capacitor element in which a capacitor portion is formed by stacking or winding the metallized film so that the vapor-deposited metal film faces through the dielectric film; and the metallization A capacitor case that houses the film capacitor element and has an opening, and a filling resin that contains the adsorbent and seals the metallized film capacitor element housed in the capacitor case and is adsorbed by the adsorbent gas is desorbed by the heat from the vehicle interior generated with the operation of the vehicle, said capacitor cable It is of the configuration in which characterized in that it is discharged through the opening of.

  As described above, the metallized film capacitor according to the present invention allows the gas adsorbed to the adsorbent to be desorbed by applying heat from the outside of the capacitor case even if the gas is adsorbed to the adsorbent. It can be discharged to the outside, so that the adsorbent can adsorb new gas entering from the outside of the capacitor. Thereby, since the adsorption capacity of the adsorbent can always be recovered, the effect of improving the reliability and realizing a metallized film capacitor capable of extending the life can be obtained.

  The invention described in the present invention will be described below using embodiments.

(Embodiment 1)
FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a metallized film capacitor according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a metallized film capacitor. The metallized film capacitor 1 includes a metallized film capacitor element 2, a capacitor case 3 for housing the metallized film capacitor element 2, and a capacitor case 3. The filled resin 4 for sealing the metallized film capacitor element 2 formed and the adsorbent 5 contained in the filled resin 4 are formed.

  The capacitor case 3 is made of a polymer such as polyphenylene sulfide (hereinafter referred to as PPS). The capacitor case 3 is formed in a bottomed cylindrical shape having an opening on the side where the metallized film capacitor element 2 is inserted.

  Here, the metallized film capacitor element 2 will be described in detail. The metallized film capacitor element 2 includes a dielectric film made of polypropylene or the like and a deposited metal film formed by vapor deposition on at least one surface of the dielectric film. The capacitor portion is formed by stacking and winding the metallized films so that the deposited metal films face each other through the dielectric film.

  One end of a terminal 6 is connected to the metallized film capacitor element 2, the metallized film capacitor element 2 housed in the capacitor case 3 is sealed with a filling resin 4, and the other end of the terminal 6 is The capacitor case 3 is exposed through the filling resin 4 from the opening.

  The adsorbent 5 is made of silica gel, activated alumina, synthetic zeolite, activated carbon or resin and has a so-called porous structure having a large number of pores. The gas is adsorbed by being physically bonded to the pores by capillary action or chemically bonded to the pore surfaces. Further, the adsorbed gas is desorbed by breaking the bond when the adsorbent 5 is heated.

  Specifically, the metallized film capacitor 1 was prepared as follows.

  A metal containing zinc was deposited on one side of a dielectric film made of polypropylene to form a metallized film on which a deposited metal film was formed.

  Next, one end of the terminal 6 is connected to the metallized film, and two metallized films connected to the terminal 6 are overlapped and wound, so that the deposited metal film is opposed to the dielectric film. The capacitor | condenser part to be formed was formed, and the metallized film capacitor | condenser element 2 was formed.

  An opening is provided on the side where the metallized film capacitor element 2 is inserted, and the metallized film capacitor element 2 is inserted into the capacitor case 3 made of PPS so that the terminal 6 extends from the opening of the capacitor case 3. Stored to be exposed.

  Filling the capacitor case 3 with a filling resin 4 made of an epoxy resin containing an adsorbent 5 to the opening of the capacitor case 3 and curing the filling resin 4 to seal the metallized film capacitor element 2. Thus, a metallized film capacitor 1 was obtained.

  As described above, according to the configuration of the first embodiment, the adsorbent 5 adsorbs the gas existing from the outside of the capacitor in addition to adsorbing the gas existing inside the metallized film capacitor 1. Even if the adsorption capacity reaches the limit, the adsorption capacity of the adsorbent 5 can be recovered by desorbing the gas adsorbed on the adsorbent 5 by heat from the outside of the capacitor case 3.

  Further, the desorbed gas dissolves in the filling resin 4 and moves through the filling resin 4 and the adsorbent 5, so that it does not enter the metallized film capacitor element 2 and enters the opening of the capacitor case 3. It can be released to the outside. Thereby, re-adsorption to the adsorbent 5 can be prevented.

  By allowing the adsorbed gas to be desorbed and released, the adsorbent can recover the adsorption capacity and adsorb new gas entering from the outside of the capacitor. It becomes possible to further improve the reliability and extend the service life.

  It will be described in detail that the gas adsorbed by the adsorbent 5, which is a feature of the present invention, is desorbed and gas is released from the opening of the capacitor case 3.

  First, heat is applied from the outside of the capacitor case 3 and the adsorbent 5 is heated, whereby the gas adsorbed in the pores of the adsorbent 5 is desorbed from the pores, and the gas dissolves in the filling resin 4 (penetration). To do). Since this gas is desorbed, the adsorbent 5 has more adsorbable pores, so that the adsorption capability of the adsorbent 5 is recovered and the gas can be adsorbed again.

  At this time, since the gas solubility of the filling resin 4 that is solid (meaning the degree to which the gas can be dissolved) is low, the amount of gas that is desorbed from the adsorbent 5 and dissolved in the filling resin 4 is limited. Become a thing. Further, since the desorbed gas dissolves in the filling resin 4 and moves in the filling resin 4, the moving speed becomes slow.

  Further, the desorbed gas has a low gas concentration and moves in the filling resin 4 in the direction of diffusion. In addition, the desorbed gas may be adsorbed by the desorbed original adsorbent 5 or another adsorbable 5 that can be adsorbed, but desorbed again while being heated to form the filled resin 4. It melts.

  Here, in the opening of the capacitor case 3, the desorbed gas is dissolved and released into the open air having high solubility. Since the gas can move quickly in the outside air, it is released and diffuses quickly, and is discharged to the outside of the opened capacitor case. Therefore, the change in the gas concentration of the outside air is small and the solubility remains high.

  Then, the gas is released, and the gas concentration of the filling resin 4 in the opening is lowered, so that the gas dissolved in the filling resin 4 is moved to the opening, and the gas is gradually desorbed from the adsorbent 5, It can be dissolved in the filling resin 4. Furthermore, since the solubility of outside air is high, the gas that has moved to the opening can be gradually released from the opening.

  The adsorption and desorption of the gas with respect to the adsorbent 5 are reversible, and the gas is released from the opening of the capacitor case 3 every time heat is applied from the outside, so that the adsorption power is restored. It becomes possible to obtain reliability.

  The capacitor case 3 is provided with an opening. However, the gas intrusion from the opening has a low solubility in the gas of the solid filling resin 4, so that the gas dissolved in the filling resin 4 is small. In addition to the slow movement of the gas in the filling resin 4 and the inability to immediately enter the metallized film capacitor element 2, the gas is adsorbed by the adsorbent 5 even if dissolved in the filling resin 4, so that the metallized film The gas entering the capacitor element 2 is extremely small, and it is considered that the characteristics of the metallized film capacitor 1 are hardly deteriorated.

  Further, when the adsorbent 5 is not contained in the filling resin 4 and the adsorbent 5 is simply arranged inside the capacitor, the adsorbent 5 is removed from the adsorbent 5 into the air at a time by heat from the outside of the capacitor case 3. Since it is separated and diffused inside the capacitor, there is a possibility that gas may enter the inside of the metallized film capacitor element 2, and the effect of the present invention cannot be obtained.

  Furthermore, in a conventional metalized film capacitor using an adsorbent inside the capacitor, it is possible to desorb the adsorbed gas by heating from the outside, but it can be released because the capacitor case is sealed. Since it cannot be adsorbed by the adsorbent again, the effect of the present invention for recovering the adsorbing capacity of the adsorbent cannot be obtained.

  Moreover, desorption and release of gas can be advanced rapidly by applying high thermal energy, and the adsorption capacity can be improved. However, in order not to deteriorate the characteristics of the metallized film capacitor 1, heat at a heat resistant temperature or lower is used. Preferably it is done.

  In particular, by disposing the metallized film capacitor 1 inside the vehicle in the vicinity of the engine room of the vehicle, the heat from the inside of the vehicle accompanying intermittent operation of the vehicle is desorbed and regenerated as heat from the outside of the capacitor case 3. It can be used for repeated adsorption, and high long-term reliability can be obtained without any special heating means. Therefore, the life span can be extended, so that the frequency of parts replacement can be reduced, which makes it useful as an electronic part used inside a vehicle with a complicated structure and difficult part replacement.

  In addition, it is not limited to the arrangement inside the vehicle in the vicinity of the engine room in order to use the heat from the inside of the vehicle. In addition to this, the adsorbent 5 uses the heat accompanying the operation of the vehicle as the heat from the outside of the capacitor case 3. It may be arranged at a location inside the vehicle where gas can be desorbed from the vehicle.

  In this embodiment, the metallized film capacitor element 2 in which the terminals are connected to the metallized film and overlapped and wound is used. However, the metallized film is laminated and the terminal electrodes are formed by metal spraying on both end faces. And what joined the terminal to this terminal electrode may be used.

  Further, if the capacitor case 3 made of metal such as aluminum is used, the gas entering from the outside of the capacitor can be reduced and the reliability can be improved. However, the use of the capacitor case 3 made of polymer reduces the cost. In addition, an effect that the weight can be reduced can be obtained.

  Further, the opening provided in the capacitor case 3 is for discharging the gas released from the filling resin 4 to the outside, and a sealing plate having a hole for discharging the gas to the outside is provided in the opening of the capacitor case 3. In this case, the sealing plate can prevent the gas from entering from the opening of the capacitor case 3 to the inside.

  Further, if a pressure regulating valve that is opened at a constant pressure is provided in the hole for discharging the gas to the outside, the valve is only opened when the internal pressure rises due to gas discharge from the opening of the capacitor case 3. Since the gas can be released to the outside and the valve is closed in other cases, the invasion of gas from the outside can be further prevented.

  Also, the larger the specific surface area represented by the ratio of the surface area including the inside of the pores of the adsorbent 5 and the volume is, the more the adsorption capacity is increased and the reliability is improved. Good.

  Furthermore, when there is a correlation between the pore diameter of the adsorbent 5 and the adsorption characteristics, the pore diameter may be adjusted in order to adjust the adsorption characteristics according to the purpose of adsorption.

(Embodiment 2)
Next, a second embodiment will be described.

  In the second embodiment, silica gel is used as the adsorbent 5 in the first embodiment, the adsorbent 5 is dispersed in the filling resin 4, and a protective layer is provided on the outer peripheral portion of the metallized film capacitor element 2. The metallized film capacitor element 2 is characterized in that a terminal electrode is formed at both ends and a terminal is connected to the terminal electrode, and the other configuration is the same as in the first embodiment. The description thereof will be omitted.

  FIG. 2 is a schematic cross-sectional view showing the metallized film capacitor in the second embodiment. In FIG. 2, 7 represents a metallized film capacitor. The metallized film capacitor 7 is housed in the metallized film capacitor element 2, a capacitor case 3 for housing the metallized film capacitor element 2, and the capacitor case 3. It is formed of a filling resin 4 for sealing the metallized film capacitor element 2 and an adsorbent 5 contained in the filling resin 4.

  The adsorbent 5 has the same specific gravity as that of the filled resin 4, is uniformly dispersed in the filled resin 4, and is made of silica gel powder having a particle size of 0.5 mm or less. The specific gravity of the adsorbent 5 is an apparent specific gravity calculated from the volume of the adsorbent 5 including pores.

  A protective layer 8 is formed by winding a thick film around the outer peripheral portion of the metallized film capacitor element 2. Further, terminal electrodes 9 are formed by metal spraying on both ends of the metallized film capacitor element 2 provided with the protective layer 8, and the terminals 6 are connected to the terminal electrodes 9.

  Specifically, the metallized film capacitor 7 was prepared as follows.

  A metallized film capacitor is formed by depositing a metal containing zinc on one side of a dielectric film made of polypropylene to form a metallized film on which a vapor-deposited metal film is formed. Element 2 was created.

  A protective film 8 was formed by winding a thick film around the outer periphery of the metallized film capacitor element 2. Further, terminal electrodes 9 were formed on both ends of the metallized film capacitor element 2 by metal spraying, and the terminals 6 were connected to the terminal electrodes 9.

  Next, this metallized film capacitor element 2 is housed in a capacitor case 3 made of PPS, and the metallized film capacitor element 2 is made using a filling resin 4 in which an adsorbent 5 made of silica gel and an epoxy resin are mixed. The metallized film capacitor 7 was obtained by sealing.

  As described above, according to the configuration of the second embodiment, the adsorbent 5 is uniformly dispersed in the filling resin 4 so that the desorbed gas is quickly adsorbed and moved to another adsorbent 5. Thus, the gas can be released from the opening of the capacitor case 3 without moving to the metallized film capacitor element 2.

  This will be described in detail with reference to a partially enlarged view of FIG.

  Since the adsorbent 5 is uniformly dispersed in the filling resin 4, the adsorbent 5 in the vicinity of the opening of the capacitor case 3 releases the desorbed gas from the opening by being given thermal energy. Therefore, the state returns to an adsorbable state, and the gas desorbed from the other adsorbent 5 inside the capacitor case 3 is re-adsorbed.

  Since the adsorbents 5 are evenly dispersed in the filled resin 4 so that the intervals between the adsorbents 5 are uniform, the desorption / readsorption of the adsorbents 5 is linked via the adsorbents 5 as shown in FIG. Can be generated automatically. As a result, the gas adsorbed by the adsorbent 5 on the inner side of the capacitor case 3 can quickly move to the opening and be released.

  Further, since the protective layer 8 is provided on the outer peripheral portion of the metallized film capacitor element 2, even if the gas is desorbed from the adsorbent 5 and moves to the metallized film capacitor element 2 and comes into contact with the protective layer 8. Since the protective layer 8 does not form a capacitor portion, it is possible to prevent deterioration of the capacitor characteristics. Thereby, the reliability can be further improved.

  In addition, by using silica gel that has a high adsorptivity near room temperature and a high desorption property at around 100 ° C., the adsorbent 5 can be desorbed by heat below the heat-resistant temperature of around 100 ° C. Thus, adsorption and desorption can be efficiently performed without deteriorating the characteristics of the capacitor due to the application of heat above the heat-resistant temperature.

  In particular, since silica gel can selectively adsorb water vapor, moisture can be prevented from entering the metallized film capacitor element 2, thereby improving the moisture resistance of the metallized film capacitor 7. It will be possible.

  Further, by providing terminal electrodes 9 by metal spraying on both ends of the metallized film capacitor element 2 around which the metallized film is wound, the gap between the end surfaces of the metallized film capacitor element 2 is filled, and the adsorbent 5 is made of metal. Since it does not penetrate into the inside of the oxidized film capacitor element 2, the electric field concentration between the metalized films due to the adsorbent 5 does not occur, so that the withstand voltage characteristics can be improved.

  In addition, since the epoxy resin before curing used for the filling resin 4 is viscous and moves slowly in the liquid, the specific gravity is made the same as the apparent specific gravity of the adsorbent 5, so that these two can be simply set. By simply mixing, a uniform dispersion state with little change over time can be obtained.

  Further, in order to disperse the adsorbent 5 in the filling resin 4, the adsorbent 5 was mixed and dispersed before sealing, but after the adsorbent 5 having a specific gravity smaller than that of the filling resin 4 was put into the capacitor case 3. The filling resin 4 may be poured.

  In this case, since the adsorbent 5 floats, in addition to being able to visually confirm the dispersion state, it is possible to obtain an effect of further preventing gas from entering from the opening by floating the adsorbent to the opening. It is.

  Further, even when the specific gravity of the adsorbent 5 is larger than the filling resin 4, the adsorbent 5 is dispersed in the filling resin 4 by pouring the filling resin 4 into the capacitor case 3 and then allowing the adsorbent 5 to be allowed to settle. You may do it.

  Furthermore, when the specific gravity difference is large, the dispersion tends to be biased with time after mixing, so that the mixed filling resin is quickly cured, or a uniform dispersion state is formed by adding a dispersant or the like. It is good to do so.

  In addition, a thick film is wound around the outer peripheral portion of the metallized film capacitor element 2 to form the protective layer 8. By using this thick film having a gas barrier property, further invasion of gas can be prevented. Is possible.

  Furthermore, the metallized film and the film on which the vapor-deposited metal film is not formed are overlapped and wound so that the film on which the vapor-deposited metal film is not formed is wound more than one turn longer than the end of the metallized film. For example, the effect that the protective layer 8 can be easily formed on the outer peripheral portion simultaneously with the formation of the metalized film capacitor element 2 can be obtained.

  If the adsorbent 5 has gas selectivity other than water vapor and selectively adsorbs corrosive gas such as chlorine gas which deteriorates the metallized film capacitor element 2, the reliability of the metallized film capacitor 7 can be obtained. It becomes possible to improve the property.

(Embodiment 3)
Next, a third embodiment will be described.

With the third embodiment using a silicone rubber having a gas permeability Filling resin 4 has a feature in was modified to form a filled resin film 11 surrounding the metallized film capacitor element 2, Since other points have the same configuration as that of the first embodiment, description thereof is omitted.

  FIG. 4 is a schematic cross-sectional view showing the metallized film capacitor in the third embodiment. In FIG. 4, reference numeral 10 denotes a metallized film capacitor. The metallized film capacitor 10 is housed in the metallized film capacitor element 2, a capacitor case 3 for housing the metallized film capacitor element 2, and the capacitor case 3. The metallized film capacitor element 2 is formed of a filling resin 12 made of silicone rubber and an adsorbent 5 contained in the filling resin 12.

Then, the metalized film capacitor element 2 has been formed by winding a metallized film, its both ends Metariko down is formed by metal spraying, the terminal 6, respectively are connected to the Metariko down .

  Specifically, the metallized film capacitor 10 was prepared as follows.

The metallized film Turn two overlapping and winding, forming a metallized film capacitor element 2, forms a Metariko down by metal spraying at both ends of the metalized film capacitor element 2, the terminal 6 in this Metariko down Connected.

  Next, the metallized film capacitor element 2 is accommodated in a capacitor case 3 made of PPS, and the metallized film capacitor element 2 is made using a filling resin 12 in which an adsorbent 5 made of silica gel and silicone rubber are mixed. The metallized film capacitor 10 was obtained by sealing.

  In the present embodiment, since the filling resin 12 has gas permeability and the gas dissolved in the filling resin 12 is easy to move, the gas adsorbed on the adsorbent 5 is quickly transferred to the capacitor by heat from the outside of the capacitor. It becomes possible to discharge from the opening of the case 3. Thereby, the reliability of the metallized film capacitor 10 can be further improved.

  Further, since the silicone rubber used for the filling resin 12 has high elasticity, the temperature change of the usage environment is greatly applied to the metallized film capacitor 10, and the capacitor case 3 and the metallized film capacitor element 2 expand and contract. In addition, since the filling resin 12 absorbs the stress, it is possible to prevent the filling resin 12 from being cracked, whereby the reliability of the metallized film capacitor 10 can be improved.

  In addition, when a filling resin having gas permeability is simply used for a conventional capacitor, the gas cannot be released, but the gas is dissolved in the filling resin that is easy to move and stays inside the capacitor. The invading gas is increased, and the characteristics of the capacitor are deteriorated. For this reason, the effect peculiar to this invention cannot be acquired, and filling resin with high gas permeability cannot be used.

Furthermore, by surrounding the metallized film capacitor element 2 with the filled resin film 11 , the adsorbent 5 can be prevented from entering the metallized film capacitor element 2 through the gap between the metallized films. Since the electric field concentration between the metallized films due to the adsorbent 5 does not occur, the withstand voltage characteristic can be improved.

The filling resin film 11 is made of a resin having a low gas permeability such as an epoxy resin and a high barrier property, thereby preventing the gas dissolved in the filling resin 12 from entering the metallized film capacitor element 2. Can do.

(Embodiment 4)
Next, a fourth embodiment will be described.

  The fourth embodiment is characterized in that the adsorbent 5 in the first embodiment is changed to one that selectively adsorbs oxygen, and the other points have the same configuration as in the first embodiment. Therefore, the explanation is omitted.

  The adsorbent 5 has a pore surface chemically modified with octylamine so that oxygen can be selectively adsorbed.

  In the present embodiment, even if the adsorbent 5 adsorbs oxygen, the adsorbed oxygen is desorbed by the heat from the capacitor case exterior 3 and released from the opening of the capacitor case 3. Can adsorb new oxygen, thereby preventing oxygen from entering the metallized film capacitor element 2 and preventing deterioration of the film due to oxidation or loss of the deposited metal film. The reliability of the capacitor 1 can be improved and the life can be extended.

  In particular, since deterioration in characteristics due to oxidation at high temperature can be prevented, heat resistance against operation at high temperature can be improved.

  Further, in addition to selectively adsorbing oxygen by chemically modifying the pore surface of the adsorbent 5, a material having a pore diameter slightly larger than the molecular diameter of oxygen molecules of 3 angstroms may be used.

(Comparative Example 1)
Next, Comparative Example 1 will be described.

  Comparative Example 1 is characterized in that the particle size of the adsorbent 5 in the second embodiment is changed to 3 mm, and the other points have the same configuration as in the second embodiment. Description is omitted.

  Since the adsorbent 5 has a larger particle size and a smaller adsorption area per volume than an adsorbent with a smaller particle size, the adsorbing capacity is reduced.

(Comparative Example 2)
In Comparative Example 2, as a metallized film capacitor using a conventional adsorbent, a sealing plate (not shown) having a hole through which the terminal 6 of Embodiment 2 is inserted is changed to provide an opening of the capacitor case 3. The other features are the same as those of the second embodiment, and the description thereof will be omitted.

  This sealing plate is provided at the opening of the capacitor case 3, the peripheral edge portion is drawn, and a packing is provided in a hole through which the terminal 6 is inserted to seal the metallized film capacitor 7 together with the capacitor case 3. is there.

(Comparative Example 3)
Comparative Example 3 is characterized in that it is changed to use the filled resin 4 that does not contain the adsorbent of Comparative Example 2 as a conventional metallized film capacitor that does not use the adsorbent. Since it has the same configuration as that of Embodiment 2, the description thereof is omitted.

  The durability test of the metallized film capacitor rated 500V and 400 μF produced by the above method was conducted. The test is performed at a test environment of 85% humidity and a temperature of 85 ° C. for 100 hours, and then the rated voltage is applied to the capacitor under a heat cycle condition in which the temperature is raised to 100 ° C. and a cycle of 100 hours is repeated. A durability test was conducted as a product. The results are shown in (Table 1).

  As a result of the test, Comparative Example 2 was destroyed after 15 cycles of energization. The initial capacity decrease was small, and the adsorbent 5 prevented the intrusion of moisture in the air, thereby preventing the disappearance of the deposited metal film, but the film gradually deteriorated due to the ingress of moisture beyond the adsorption capacity. It was thought that the metal film was destroyed because of the disappearance of the deposited metal film.

  Further, Comparative Example 3 was destroyed after 10 cycles of energization. Since there is no adsorbent, the adsorbent could not prevent the intrusion of moisture in the air, and since the ingress of moisture gradually caused deterioration of the film and the disappearance of the deposited metal film, it was considered to have been destroyed.

  In the second embodiment, destruction occurred after 100 cycles of energization. The adsorption capacity of the adsorbent can be restored by desorbing and releasing the gas adsorbed by the heat from the outside of the capacitor case, so that more gas is adsorbed and penetrates into the capacitor. I was able to prevent it. Thus, it is considered that the reliability was improved and the life could be extended compared with the comparative example of the conventional product.

  Further, Comparative Example 1 was destroyed after 20 cycles of energization. This is presumably because the adsorbent 5 has a large particle size, the specific surface area is reduced, and the amount of adsorbed gas is reduced.

  Even if the adsorbent adsorbs gas, the metallized film capacitor according to the present invention can desorb the adsorbed gas by applying heat to the adsorbent and release it to the outside of the capacitor case. The adsorbent will be able to adsorb new gas. As a result, the effect of improving the reliability and realizing a metallized film capacitor capable of extending the life is obtained, and is useful as a metallized film capacitor for electronic devices.

Sectional schematic diagram showing a schematic configuration of the metallized film capacitor according to Embodiment 1 of the present invention. Sectional schematic diagram showing a schematic configuration of the metallized film capacitor in the second embodiment Partial enlarged view showing desorption operation of adsorbed gas in the same metallized film capacitor Sectional schematic diagram showing a schematic configuration of the metallized film capacitor in the third embodiment Cross-sectional schematic diagram of a conventional metalized film capacitor Perspective view of the metallized film capacitor element Cross-sectional schematic diagram of a conventional metalized film capacitor

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 7, 10 Metallized film capacitor 2 Metallized film capacitor | condenser element 3 Capacitor case 4, 12 Filling resin 5 Adsorbent 8 Protective layer 9 Terminal electrode 11 Filling resin film

Claims (10)

It is a metallized film capacitor mounted on a vehicle,
A metallized film comprising a dielectric film and a deposited metal film deposited on at least one surface of the dielectric film;
A metallized film capacitor element in which a capacitor portion is formed by the metallized film being laminated or superposed and wound so that the vapor-deposited metal film faces through the dielectric film;
A capacitor case containing the metallized film capacitor element and having an opening;
Sealing the metallized film capacitor element housed in the capacitor case and comprising a filling resin containing an adsorbent ,
The metallized film capacitor, wherein the gas adsorbed by the adsorbent is desorbed by heat from the inside of the vehicle generated by the operation of the vehicle and discharged from the opening of the capacitor case. The metallized film capacitor according to claim 1, wherein a specific gravity of the adsorbent is equal to or less than a specific gravity of the filled resin. The metallized film capacitor according to claim 1, wherein the adsorbent has gas selectivity. The metallized film capacitor according to claim 1, wherein the adsorbent selectively adsorbs water vapor. The metallized film capacitor of claim 1, wherein the adsorbent selectively adsorbs oxygen. The metallized film capacitor according to claim 1, wherein the adsorbent is made of silica gel. The metallized film capacitor according to claim 1, wherein a protective layer made of a film is provided on at least an outermost layer of the metallized film capacitor element. 2. The metallized film capacitor according to claim 1, wherein the metallized film capacitor element is formed by overlapping and winding a metallized film, and terminal electrodes are formed by metal spraying at both ends of the metallized film capacitor element. . The metallized film capacitor according to claim 1, wherein the filling resin has gas permeability. The metallized film capacitor according to claim 1, wherein the filling resin is made of silicone rubber.

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