Large-current axial high-frequency resonant capacitor and manufacturing method thereof

Abstract

The invention relates to a large-current axial high-frequency resonant capacitor and a manufacturing method thereof, the large-current axial high-frequency resonant capacitor comprises a capacitor core and a shell, the capacitor core is formed by winding a double-sided metal film, a single-sided metal film and an intermediate film arranged between the double-sided metal film and the single-sided metal film, a metal spraying layer is sprayed on the surface of the substrate; the housing is arranged on the outer side of the capacitor core, and a sealing pouring material is arranged between the housing and the capacitor core. According to the structure, the voltage resistance field intensity and the self-healing performance of the capacitor can be improved, the size is smaller, the number of welding points for parallel connection of capacitor cores is reduced, the fault rate of insufficient welding of the capacitor is reduced, meanwhile, the use safety of the capacitor can be effectively improved, and flashover generated by creepage is avoided.

Description

[0001] Divisional application, original application number: 202210045547.8, application date: January 15, 2022; Invention name: A high-current axial high-frequency resonant capacitor and its manufacturing method. Technical Field

[0002] The invention relates to the field of capacitors, in particular to a large current axial high frequency resonant capacitor and a manufacturing method thereof. Background Art

[0003] The Chinese patent document number CN2899063Y disclosed a high-frequency resonant heating capacitor on May 9, 2007, which includes a shell, an electrode and a capacitor core group composed of several capacitor unit cores connected together. The capacitor core group is surrounded by an insulating filler and placed in the shell. The capacitor has a dry structure, and a cooler is buried inside the capacitor. The two lead ends of the cooler are connected to an external cooling pipe. The heat generated by the capacitor during operation can be dissipated through the cooler. However, in actual use, the heat inside the capacitor is difficult to dissipate, and the temperature rises, which makes it easy to fail, burn and other negative effects, and the service life is short, which brings certain adverse effects to people's use. Therefore, it is necessary to make further improvements. Summary of the invention

[0004] The object of the present invention is to provide a large current axial high frequency resonant capacitor and a manufacturing method thereof, so as to overcome the deficiencies in the prior art.

[0005] A high-current axial high-frequency resonant capacitor designed for this purpose includes a capacitor core and a shell, and is characterized in that: the capacitor core is wound by a double-sided metal film, a single-sided metal film, and an intermediate film arranged between the double-sided metal film and the single-sided metal film, and is provided with heat conduction holes inside and a gold spray layer on the surface; the shell is arranged on the outside of the capacitor core, and a sealing potting material is also arranged between them.

[0006] The double-sided metal film comprises a first thin film medium and double-sided conductive metal layers distributed on both sides of the first thin film medium; the double-sided conductive metal layers are mutually provided with double-sided middle margins.

[0007] The single-sided metal film includes a second thin film medium and a single-sided conductive metal layer distributed on a single side of the second thin film medium; the single-sided conductive metal layers are provided with single-sided middle margins between each other, and the single-sided conductive metal layers are provided with single-sided outer margins on the outside.

[0008] The intermediate film is a light film, or the intermediate film is a metal film with the same structure as the single-sided metal film, and the single-sided conductive metal layers of the two are inverted.

[0009] There are a plurality of double-sided middle margins; the double-sided conductive metal layer is distributed on both sides of the first thin film medium at equal distances and sizes through the plurality of double-sided middle margins.

[0010] Alternatively, one double-sided center margin is provided; and the double-sided conductive metal layer is distributed on both sides of the first thin film medium through one double-sided center margin.

[0011] The single-sided conductive metal layer is provided with a single-sided center margin and a single-sided outer margin; there are a plurality of the single-sided center margins; the single-sided outer margins are arranged on both outer sides of the single-sided conductive metal layer; the single-sided conductive metal layer is distributed on the single side of the second thin film medium with equal distances and sizes through the coordination of a plurality of the single-sided center margins and the single-sided conductive metal layers on both outer sides.

[0012] The single-sided outer margins are arranged on both outer sides of the single-sided conductive metal layer, and the single-sided outer margins are arranged in the middle position of the single side of the second thin film medium through the two outer sides.

[0013] The size of the first thin film medium is larger or smaller than the size of the second thin film medium and the intermediate film.

[0014] The size of the second thin film medium is the same as that of the intermediate film.

[0015] The size of the single-sided conductive metal layer is greater than or equal to the size of the double-sided conductive metal layer.

[0016] The size of the double-sided middle margin is the same as the size of the single-sided middle margin.

[0017] The size of the single-sided inner margin is larger or smaller than the size of the single-sided outer margin.

[0018] The first thin film medium and the second thin film medium are both polypropylene films or polyester films; the double-sided conductive metal layer and the single-sided conductive metal layer are both aluminum-plated layers.

[0019] The shell is an insulating explosion-proof shell, and its upper and lower end surfaces are open; the capacitor core is placed in the shell; and lead nuts are respectively arranged at the upper and lower ends of the heat conduction hole.

[0020] The lead-out nut is axially and linearly extended on the outer side and is arranged in the heat conduction hole, and the end surface of the lead-out nut is higher than the end surface of the capacitor core; Alternatively, the inner side of the lead-out nut is axially and linearly extended and arranged in the heat conducting hole, and a nut annular side edge is extended from the outer side of the lead-out nut, and is covered on the end face of the capacitor core by the nut annular side edge; Alternatively, the inner side of the lead-out nut is axially extended linearly and arranged in the heat conducting hole, the outer side of the lead-out nut is provided with a nut annular side, and a metal piece is connected through the nut annular side, and is covered on the capacitor core in cooperation with the metal piece; The sealing potting material is poured between the housing, the capacitor core, the lead nut or the metal part.

[0021] The shell is a metal explosion-proof shell, and two of them are provided. The two shells are respectively arranged in an annular shape outside the capacitor core, and the end faces thereof are flush with each other; the upper and lower ends of the heat conduction hole are respectively provided with lead-out copper blocks.

[0022] The inner side of the lead-out copper block is axially and linearly extended and arranged in the heat conduction hole. The outer side of the lead-out copper block is provided with an annular groove, and is covered on the capacitor core and the end surface of the shell through the annular groove.

[0023] The sealing potting material is poured between the shell, the capacitor core and the lead-out copper block.

[0024] A method for manufacturing a high-current axial high-frequency resonant capacitor, characterized in that it includes the above-mentioned high-current axial high-frequency resonant capacitor; wherein the manufacturing method is as follows: Step 1: The double-sided metal film, the intermediate film, and the single-sided metal film are stacked in sequence from top to bottom, and then wound by a winding machine to form the cylindrical capacitor core; Step 2: spraying the gold spray layer on the capacitor core, wherein the gold spray layer is sprayed several times, with zinc spraying twice at the beginning and zinc-tin alloy spraying twice at the end; Step 3: placing the capacitor core sprayed with the gold spray layer in the housing; Step 4: placing the lead nuts at upper and lower positions inside the heat conduction hole, respectively, wherein the upper and lower end surfaces of the lead nuts are respectively 3-8 mm higher than the end surface of the capacitor core; Step 5: A welding hole is provided on the lead nut, and low-temperature solder paste is applied to the bottom of the lead nut and the position of the gold-sprayed layer facing the capacitor core, and then the welding hole is welded by high-temperature tinning to complete welding and fixing between the bottom of the lead nut and the gold-sprayed layer of the capacitor core; Step 6: The upper and lower lead nuts are respectively provided with holes, one of which is a through hole and the other is a non-through hole. Lead electrodes are provided on the through holes of the lead nuts, and then the sealing potting material is used to seal and package the end faces of the shell, the capacitor core, the lead nut or metal part, and the lead electrodes to finally complete the manufacture of the large current axial high-frequency resonant capacitor.

[0025] A method for manufacturing a high-current axial high-frequency resonant capacitor, characterized in that it includes the above-mentioned high-current axial high-frequency resonant capacitor; wherein the manufacturing method is as follows: Step 1: The double-sided metal film, the intermediate film, and the single-sided metal film are stacked in sequence from top to bottom, and then wound by a winding machine to form the cylindrical capacitor core; Step 2: spraying the gold spray layer on the capacitor core, wherein the gold spray layer is sprayed several times, with zinc spraying twice at the beginning and zinc-tin alloy spraying twice at the end; Step 3: The two shells are respectively placed on the upper and lower outer sides of the capacitor core sprayed with the gold layer; Step 4: Two lead-out copper blocks are provided, and the annular grooves of the two lead-out copper blocks are provided with a diameter of 1-5 mm, and solder paste is applied inside them respectively. The lead-out copper blocks are placed on a heating platform or by means of induction heating, so that all the solder paste is dissolved inside the annular grooves; Step 5: Press the upper and lower positions of the capacitor core into the two annular grooves for 1-7 seconds respectively, so that the two lead-out copper blocks are welded and fixed to the end faces of the capacitor core, and then place them in an industrial alcohol box for cooling; Step 6: The two lead-out copper blocks are respectively provided with holes, one of which is a through hole and the other is a non-through hole, and lead-out electrodes are provided on the through holes of the lead-out copper blocks, and then the sealing potting material is used to seal and package the side positions between the shell, the capacitor core, and the lead-out copper blocks, so as to finally complete the manufacture of the large current axial high-frequency resonant capacitor.

[0026] The present invention has the following advantages compared with the prior art through the improvement of the above structure: 1. The double-sided metal film is separated by a gap in the middle, which can increase the current-carrying cross-sectional area of ​​the capacitor and increase the current-carrying capacity of the capacitor; the double-sided metal film, the intermediate film, and the single-sided metal film are polypropylene film or polyester film dielectrics, and the metal layer is aluminum-plated, thereby increasing the self-healing property of the double-sided metal film, the intermediate film, and the single-sided metal film; the aluminum layer of the double-sided metal film is used as the electrode to improve the withstand voltage field strength and self-healing performance of the capacitor, and the volume is smaller, the number of parallel solder joints of the capacitor core is reduced, and the failure rate of cold soldering of the capacitor is reduced.

[0027] 2. The setting of the double-sided middle margin, the single-sided middle margin, and the single-sided outer margin is intended to ensure that there is a certain insulation strength between the double-sided metal film, the intermediate film, and the single-sided metal film when the capacitor is wound. At the same time, the setting size between the margins has a certain range. On the basis of controlling the production cost of the capacitor, it effectively improves the safety distance of the capacitor's high voltage resistance and avoids arcing caused by creepage.

[0028] 3. The double-sided metal film forms the plates of the capacitor and has good self-healing properties. This is the most critical area for forming capacitance and maintaining the electrical properties of the capacitor. It can ensure the appropriate proportion of metal components, prevent electrochemical corrosion under AC conditions, and improve the relative withstand voltage of the capacitor. At the same time, the double-sided aluminum coating can also change the capacitor's withstand voltage, pulse, dv / dt and other electrical properties, and can be used as high-frequency and high-current resonance in induction heating equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the exploded structure of the first application example of the capacitor core of the first embodiment of the present invention.

[0030] Figure 2 It is a schematic diagram of the exploded structure of the second application example of the capacitor core of the first embodiment of the present invention.

[0031] Figure 3 It is a schematic diagram of the exploded structure of the third application example of the capacitor core of the first embodiment of the present invention.

[0032] Figure 4 It is a schematic diagram of the exploded structure of the fourth application example of the capacitor core of the first embodiment of the present invention.

[0033] Figure 5 It is a schematic diagram of the capacitor assembly structure of the first embodiment of the present invention.

[0034] Figure 6 It is a schematic diagram of the cross-sectional structure of the capacitor assembly according to the first embodiment of the present invention.

[0035] Figure 7 It is a schematic diagram of the capacitor assembly structure according to the second embodiment of the present invention.

[0036] Figure 8 This is a schematic cross-sectional view of a capacitor assembly according to a second embodiment of the present invention.

[0037] Fig. 9 , Fig.10 It is a schematic diagram of the lead-out nut structure of the second embodiment of the present invention.

[0038] Fig.11 It is a schematic diagram of the capacitor assembly structure according to the third embodiment of the present invention.

[0039] Fig.12 It is a schematic diagram of a cross-sectional structure of a capacitor assembly according to a third embodiment of the present invention.

[0040] Fig.13 , Fig.14 It is a schematic diagram of the lead-out nut structure of the third embodiment of the present invention.

[0041] Fig.15It is a schematic diagram of the capacitor assembly structure according to the fourth embodiment of the present invention.

[0042] Fig.16 It is a schematic diagram of a cross-sectional structure of a capacitor assembly according to a fourth embodiment of the present invention.

[0043] Fig.17 FIG. 5 is a schematic diagram of a capacitor assembly structure according to a fifth embodiment of the present invention.

[0044] Fig.18 It is a schematic cross-sectional view of a capacitor assembly according to a fifth embodiment of the present invention.

[0045] Fig.19 This is a schematic diagram of the lead-out nut structure of the fifth embodiment of the present invention. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings and embodiments. First embodiment

[0047] See also Figure 1-Figure 6 The high-current axial high-frequency resonant capacitor includes a capacitor core 1 and a shell 3. The capacitor core 1 is wound by a double-sided metal film, a single-sided metal film, and an intermediate film 10 arranged between the double-sided metal film and the single-sided metal film. A heat conduction hole 23 is arranged inside the capacitor core 1, and a gold spray layer 2 is sprayed on the surface; the shell 3 is arranged on the outside of the capacitor core 1, and a sealing potting material 4 is also arranged between them.

[0048] The double-sided metal film includes a first thin film medium 11 and double-sided conductive metal layers 12 distributed on both sides of the first thin film medium 11; the double-sided conductive metal layers 12 are provided with double-sided center margins 13 between each other.

[0049] The single-sided metal film includes a second thin film medium 14 and a single-sided conductive metal layer 15 distributed on a single side of the second thin film medium 14 ; the single-sided conductive metal layers 15 are provided with single-sided middle margins 16 between each other, and the single-sided conductive metal layers 15 are provided with single-sided outer margins 17 on the outside.

[0050] The intermediate film 10 is a light film, or the intermediate film 10 is a metal film with the same structure as the single-sided metal film, and the single-sided conductive metal layers 15 of the two are inverted.

[0051] The double-sided middle margins 13 are provided in a plurality; the double-sided conductive metal layer 12 is distributed on both sides of the first thin film medium 11 at equal distances and sizes through the plurality of double-sided middle margins 13 .

[0052] Alternatively, the double-sided center margin 13 is provided with one; the double-sided conductive metal layer 12 is distributed on both sides of the first thin film medium 11 through the double-sided center margin 13 .

[0053] The single-sided conductive metal layer 15 is provided with a single-sided center margin 16 and a single-sided outer margin 17; there are a plurality of the single-sided center margins 16; the single-sided outer margins 17 are arranged on both outer sides of the single-sided conductive metal layer 15; the single-sided conductive metal layer 15 is distributed on a single side of the second thin film medium 14 with equal distances and sizes through the coordination of a plurality of the single-sided center margins 16 and the single-sided conductive metal layers 15 on both outer sides.

[0054] The single-sided conductive metal layer 15 is provided with the single-sided outer margins 17 on both outer sides, and the single-sided outer margins 17 are arranged at the middle position of the single side of the second thin film medium 14 through the two outer sides.

[0055] The first thin film medium 11 and the second thin film medium 14 are both polypropylene films or polyester films; the double-sided conductive metal layer 12 and the single-sided conductive metal layer 15 are both aluminum-plated layers.

[0056] Specifically, if Figure 1 As shown, the double-sided middle margin 13 is provided with several; the double-sided conductive metal layer 12 is distributed on the double sides of the first thin film medium 11 with equal distance and size through several double-sided middle margins 13. The single-sided conductive metal layer 15 is provided with a single-sided middle margin 16 and a single-sided outer margin 17; the single-sided middle margin 16 is provided with several; the single-sided outer margin 17 is arranged on both outer sides of the single-sided conductive metal layer 15; the single-sided conductive metal layer 15 is distributed on the single side of the second thin film medium 14 with equal distance and size through the cooperation of several single-sided middle margins 16 and the single-sided conductive metal layers 15 on both outer sides. The intermediate film 10 is a metal film with the same structure as the single-sided metal film, and the single-sided conductive metal layers 15 of the two are inverted. That is, the single-sided conductive metal layer 15 of the intermediate film 10 faces downward, and the single-sided conductive metal layer 15 of the single-sided metal film faces upward.

[0057] The first film medium 11 is a polypropylene PET film, the second film medium 14 and the intermediate film 10 are polyester PP films; six series of films can be formed between the double-sided metal film, the intermediate film and the single-sided metal film. The overlapping winding between the intermediate film and the single-sided metal film can increase the plated aluminum electrodes between the capacitor core 1, which can effectively increase the capacitor's current capacity, reduce product loss, reduce ESR, and reduce product heat generation.

[0058] like Figure 2As shown, the double-sided middle margin 13 is provided with a plurality of the double-sided middle margins 13; the double-sided conductive metal layer 12 is distributed on both sides of the first thin film medium 11 at equal distances and sizes through the plurality of the double-sided middle margins 13. The single-sided conductive metal layer 15 is provided with a single-sided middle margin 16 and a single-sided outer margin 17; the single-sided middle margin 16 is provided with a plurality of the single-sided outer margins 17; the single-sided outer margins 17 are arranged on both outer sides of the single-sided conductive metal layer 15; the single-sided conductive metal layer 15 is distributed on one side of the second thin film medium 14 at equal distances and sizes through the cooperation of the plurality of the single-sided middle margins 16 and the single-sided conductive metal layers 15 on both outer sides. The intermediate film 10 is a light film, which refers to a thin film medium without a vapor-deposited metal coating.

[0059] The first film medium 11 is a polypropylene PET film, the second film medium 14 and the intermediate film 10 are polyester PP films; six series of films can be formed between the double-sided metal film, the intermediate film and the single-sided metal film. The overlapping winding between the intermediate film and the single-sided metal film can increase the plated aluminum electrodes between the capacitor core 1, which can effectively increase the capacitor's current capacity, reduce product loss, reduce ESR, and reduce product heat generation.

[0060] like Figure 3 As shown, the double-sided middle margin 13 is provided with one; the double-sided conductive metal layer 12 is distributed on both sides of the first thin film medium 11 through the double-sided middle margin 13. The single-sided outer margins 17 are provided on both outer sides of the single-sided conductive metal layer 15, and the single-sided outer margins 17 are arranged in the middle position of the single side of the second thin film medium 14 through the two outer sides. The intermediate film 10 is a metal film with the same structure as the single-sided metal film, and the single-sided conductive metal layers 15 of the two are inverted. That is, the single-sided conductive metal layer 15 of the intermediate film 10 faces downward, and the single-sided conductive metal layer 15 of the single-sided metal film faces upward.

[0061] The first film medium 11 is a polypropylene PET film, the second film medium 14 and the intermediate film 10 are polyester PP films; the double-sided metal film, the intermediate film and the single-sided metal film can form two series of films. The overlapping winding between the intermediate film and the single-sided metal film can increase the plated aluminum electrodes between the capacitor core 1, which can effectively increase the current capacity of the capacitor, reduce product loss, reduce ESR, and reduce the heat generation of the product.

[0062] like Figure 4As shown, the double-sided middle margin 13 is provided with one; the double-sided conductive metal layer 12 is distributed on both sides of the first thin film medium 11 through the double-sided middle margin 13. The single-sided conductive metal layer 15 is provided with the single-sided outer margin 17 on both sides, and the single-sided outer margin 17 is arranged in the middle position of the single side of the second thin film medium 14 through the two outer sides. The intermediate film 10 is a light film, which refers to a thin film medium without a vapor-deposited metal coating.

[0063] The first film medium 11 is a polypropylene PET film, the second film medium 14 and the intermediate film 10 are polyester PP films; the double-sided metal film, the intermediate film and the single-sided metal film can form two series of films. The overlapping winding between the intermediate film and the single-sided metal film can increase the plated aluminum electrodes between the capacitor core 1, which can effectively increase the current capacity of the capacitor, reduce product loss, reduce ESR, and reduce the heat generation of the product.

[0064] in, Figure 1-Figure 4 The double-sided metal film requires a square resistance of ≤1.2Ω / □ on one side and ≤1.0Ω / □ on the other side, and the single-sided metal film requires a square resistance of 1-3Ω / □.

[0065] The size of the first thin film medium 11 is larger or smaller than the size of the second thin film medium 14 and the intermediate film 10 .

[0066] The size of the second thin film medium 14 is the same as that of the intermediate film 10 .

[0067] The size of the single-sided conductive metal layer 15 is greater than or equal to the size of the double-sided conductive metal layer 12 .

[0068] The size of the double-sided center margin 13 is the same as the size of the single-sided center margin 16 .

[0069] The size of the single-sided inner margin 16 is larger or smaller than the size of the single-sided outer margin 17 .

[0070] like Figure 1 , Figure 2 As shown, the size of the first thin film medium 11 is W1, which is larger than the size W2 of the second thin film medium 14 and the intermediate film 10. The size of the double-sided conductive metal layer 12 and the single-sided conductive metal layer 15 are both L1. The size of the double-sided middle margin 13 and the single-sided middle margin 16 are both B1. The size B1 of the double-sided middle margin 13 and the single-sided middle margin 16 is larger than the size B2 of the single-sided outer margin 17.

[0071] like Figure 3 , Figure 4As shown, the size W1 of the first thin film medium 11 is larger than the size W2 of the second thin film medium 14 and the intermediate film 10. The size L1 of the double-sided conductive metal layer 12 is smaller than the size L2 of the single-sided conductive metal layer 15. The size B1 of the double-sided inner margin 13 is larger than the size B2 of the single-sided outer margin 17.

[0072] The housing 3 is an insulating explosion-proof housing, and its upper and lower end surfaces are open; the capacitor core 1 is placed in the housing 3; and lead nuts 5 are respectively provided at the upper and lower ends of the heat conduction hole 23.

[0073] The lead-out nut 5 is axially and linearly extended on the outside and is arranged in the heat-conducting hole 23 . The end surface of the lead-out nut 5 is higher than the end surface of the capacitor core 1 .

[0074] The sealing potting material 4 is poured between the housing 3 , the capacitor core 1 , and the lead nut 5 .

[0075] The manufacturing method of the above-mentioned high-current axial high-frequency resonant capacitor is as follows: Step 1: The double-sided metal film, the intermediate film 10, and the single-sided metal film are stacked in sequence from top to bottom, and then wound by a winding machine to form the cylindrical capacitor core 1; Step 2: spraying the gold spraying layer 2 on the capacitor core 1, wherein the gold spraying layer 2 is sprayed several times, first spraying zinc twice, and finally spraying zinc-tin alloy twice to increase solderability; Step 3: placing the capacitor core 1 sprayed with the gold spray layer 2 in the housing 3; Step 4: Place the lead-out nuts 5 at the upper and lower positions inside the heat-conducting hole 23, respectively, wherein the upper and lower end surfaces of the lead-out nuts 5 are respectively 3-8 mm higher than the end surface of the capacitor core 1, and preferably 5-6 mm in this embodiment. Step 5: A welding hole is provided on the lead-out nut 5, and low-temperature solder paste is applied to the bottom of the lead-out nut 5 and the position of the gold-sprayed layer 2 facing the capacitor core 1, and then the welding hole is welded by high-temperature tinning, so that the bottom of the lead-out nut 5 and the gold-sprayed layer 2 of the capacitor core 1 are welded and fixed; Step 6: The upper and lower lead nuts 5 are respectively provided with holes, one of which is a through hole and the other is a non-through hole. Lead electrodes are provided on the through holes of the lead nut 5, and then the sealing potting material 4 is used to seal and package the end faces of the housing 3, the capacitor core 1, the lead nut 5, and the lead electrodes, so as to finally complete the manufacture of the large current axial high-frequency resonant capacitor.

[0076] The core shaft of the capacitor core 1 is wound with a large core shaft to ensure that the heat inside the core can be dissipated through the lead nut 5. The insulating and explosion-proof shell 3 can increase the flame retardancy and explosion resistance of the capacitor core 1. The circular insulating shell is made of FR4 or SMC, which has good heat dissipation and high reliability. Compared with the paper-wrapped products, it does not burn.

[0077] In this embodiment, the upper and lower end faces of the lead-out nut 5 are preferably 5-6 mm higher than the end face of the capacitor core 1, respectively, so that the heat of the capacitor core 1 can be quickly taken away through the lead-out nut 5; the setting of the welding hole can ensure the weldability of the gold spraying layer 2 of the capacitor core 1 and the lead-out nut 5 during high-temperature welding, and the combination of high-temperature tinning welding and solder paste can quickly and evenly melt, ensuring the welding reliability of the bottom of the lead-out nut 5 and the gold spraying layer 2 of the capacitor core 1, and increasing the overcurrent capacity. The inside of the lead-out nut 5 extends to the inside of the heat-conducting hole 23, and the specific extension size is determined according to the maximum safe creepage distance insulation, and the heat inside the capacitor core 1 is quickly taken out through the inside of the lead-out nut 5. Because the lead-out electrode is in contact with the lead-out electrode through a water-cooled plate when used by customers, the lead-out nut 5 does not generate heat at all when the current is large, and the customer installs a copper plate close to the packaging surface of the capacitor core 1, through which the heat of the capacitor product itself can be quickly taken away, increasing the overcurrent capacity of the product. The sealing potting material 4 is an encapsulating epoxy resin.

[0078] Specifically, the internal extension size of the lead-out nut 5 is consistent with the inner hole size of the winding mandrel, between 18-30, and the mandrel is selected according to the size requirements. The resonant current can reach 50-150A (without water cooling) and 200-300A (with water cooling).

[0079] The high-current axial high-frequency resonant capacitor produced by the above manufacturing method can be used in the resonant circuit of high-power induction heating equipment, the series and parallel resonant circuits of various intermediate frequency, ultrasonic and other electronic equipment, as a power output transformer, primary and secondary LC parallel resonance, etc., and has a wide range of uses. Second embodiment

[0080] See also Figure 7-10 The present high-current axial high-frequency resonant capacitor and its manufacturing method are different from the first embodiment in that: the inner side of the lead-out nut 5 is axially linearly extended and arranged in the heat-conducting hole 23, and the outer side of the lead-out nut 5 is extended with a nut annular side 51, and is covered on the end face of the capacitor core 1 by the nut annular side 51.

[0081] Specifically, the internal extension size of the lead-out nut 5 is consistent with the inner hole size of the winding mandrel, and is wound on a reel with an inner diameter of 30. The outer diameter of the lead-out nut 5 is greater than 50. The resonant current can reach 150-350A (without water cooling) and 400-600A (with water cooling). The mandrel can be selected according to the size requirements.

[0082] The lead nut 5 and the annular side 51 of the nut are directly formed by copper blocks at one time, or the lead nut 5 and the annular side 51 of the nut are formed by copper blocks respectively and then welded to each other. The outer periphery of the lead nut 5 is equivalent to the size of the mandrel and serves as the welding surface of the end face of the capacitor core 1. The bottom surface of the lead nut 5 is milled and flattened, and the tapping pattern is processed after the appearance treatment is completed.

[0083] Other parts not described are the same as those in the first embodiment. Third embodiment

[0084] See also Figure 11-Figure 14 The present high-current axial high-frequency resonant capacitor and its manufacturing method are different from the first embodiment in that: the inner side of the lead-out nut 5 is axially linearly extended and arranged in the thermal conductive hole 23, and the outer side of the lead-out nut 5 is extended with a nut annular side 51, and a metal part 8 is connected through the nut annular side 51, and is covered on the capacitor core 1 in cooperation with the metal part 8.

[0085] Specifically, the outer periphery of the shell 3 and the metal part 8 is circular; a threaded portion is provided on the outer periphery of the annular side 5 of the nut, and the metal part 8 is an aluminum block or a copper block, and its inner ring is also provided with a threaded portion, which is tightly matched with the threaded portion of the annular side 5 of the nut. The lead-out nut 5 and the metal part 8 simultaneously wrap at least part of the end face and the outer side of the capacitor core 1, and the middle position of the outer side of the capacitor core 1 is wrapped by the shell 3. Two packaging explosion-proof holes are opened above the metal part 8 for the injection of the sealing potting material 4, thereby effectively ensuring the sealing of the product.

[0086] Silver paste, low-temperature solder paste, or other welding metals are applied to the contact position between the lead-out nut 5 and the metal part 8, and heated to melt them to ensure the contact between the lead-out nut 5 and the metal part 8, thereby ensuring the consistency of the heat dissipation of the product and the overall effect, thereby further enhancing the overall heat dissipation of the product. The metal part 8 can be adjusted in position according to the lead-out nut 5, thereby increasing the current flow capacity of the product, enhancing the heat dissipation capacity, and having strong practicality.

[0087] The lead nut 5 and the annular side 51 of the nut are directly formed by copper blocks at one time, or the lead nut 5 and the annular side 51 of the nut are formed by copper blocks respectively and then welded to each other. The outer periphery of the lead nut 5 is equivalent to the size of the mandrel and serves as the welding surface of the end face of the capacitor core 1. The bottom surface of the lead nut 5 is milled and flattened, and the tapping pattern is processed after the appearance treatment is completed. The outer periphery of the annular side 51 of the nut is directly processed with a threaded portion.

[0088] Other parts not described are the same as those in the first embodiment. Fourth embodiment

[0089] See also Fig.15 , Fig.16 The present high current axial high frequency resonant capacitor and its manufacturing method are different from the third embodiment in that the outer periphery of the housing 3 and the metal member 8 is square. Four mounting holes are added around the metal member 8 to facilitate the assembly of the product and further increase the heat dissipation contact capability of the product.

[0090] Other undescribed parts are the same as those in the third embodiment. Fifth embodiment

[0091] See also Figure 17-Figure 19 The present high-current axial high-frequency resonant capacitor and its manufacturing method are different from the first embodiment in that: the shell 3 is a metal explosion-proof shell, and two shells are provided, and the two shells 3 are respectively arranged in an annular manner on the outside of the capacitor core 1, and the end faces thereof are flush with each other; the upper and lower ends of the heat conduction hole 23 are respectively provided with lead-out copper blocks 6.

[0092] The inner side of the lead-out copper block 6 is axially and linearly extended and arranged in the heat conducting hole 23 . The outer side of the lead-out copper block 6 is provided with an annular groove 7 , and the end faces of the capacitor core 1 and the housing 3 are covered by the annular groove 7 .

[0093] The sealing potting material 4 is poured between the housing 3 , the capacitor core 1 , and the lead-out copper block 6 .

[0094] The manufacturing method of the above-mentioned high-current axial high-frequency resonant capacitor is as follows: Step 1: The double-sided metal film, the intermediate film 10, and the single-sided metal film are stacked in sequence from top to bottom, and then wound by a winding machine to form the cylindrical capacitor core 1; Step 2: spraying the gold spraying layer 2 on the capacitor core 1, wherein the gold spraying layer 2 is sprayed several times, with zinc spraying twice at the beginning and zinc-tin alloy spraying twice at the end; Step 3: The two shells 3 are respectively placed on the upper and lower outer sides of the capacitor core 1 sprayed with the gold spray layer 2; Step 4: Two lead-out copper blocks 6 are provided, and the annular grooves 7 of the two lead-out copper blocks 6 are provided with a diameter of 1-5 mm, and solder paste is applied inside them respectively, and the lead-out copper blocks 6 are placed on a heating platform or by means of induction heating, so that all the solder paste is dissolved inside the annular grooves 7; Step 5: Press the upper and lower positions of the capacitor core 1 into the two annular grooves 7 for 1-7s respectively, so that the two lead-out copper blocks 6 are welded and fixed to the end faces of the capacitor core 1, and then place them in an industrial alcohol box for cooling; Step 6: The two lead-out copper blocks 6 are respectively provided with holes, one of which is a through hole and the other is a non-through hole, and lead-out electrodes are arranged on the through holes of the lead-out copper blocks 6, and then the sealing potting material 4 is used to seal and package the side positions between the shell 3, the capacitor core 1, and the lead-out copper blocks 6, so as to finally complete the manufacture of the large current axial high-frequency resonant capacitor.

[0095] The shell 3 described in this embodiment is an aluminum ring or a copper ring shell, which can increase the flame retardancy and explosion resistance of the capacitor core 1. The aluminum ring and the copper ring are directly close to the capacitor core 1 and the lead-out electrode, which has good heat dissipation and high reliability. Compared with the paper-wrapped product, it does not burn. When the lead-out electrode is assembled with a water-cooled copper plate to dissipate heat, the metal ring also simultaneously dissipates the temperature of the outer core quickly. The metal ring is in direct contact with the surface of the capacitor core 1 without insulation.

[0096] When alcohol cooling is required, the depth of the cooling alcohol is less than or equal to the thickness of the lead-out electrode. This welding method effectively increases the overcurrent capacity of the capacitor core 1 and welds the entire core end face of the capacitor to the lead-out copper block 6 electrode.

[0097] The lead-out copper block 6 extends inside the heat-conducting hole 23, and the specific extension size is determined according to the maximum safe creepage distance insulation, and the heat inside the capacitor core 1 is quickly taken out through the lead-out copper block 6. Because the lead-out electrode is in contact with the lead-out electrode through a water-cooled plate when used by customers, the lead-out copper block 6 does not generate heat at all under high current, and the copper plate installed by the customer is in contact with the entire lead-out copper block 6, and water-cooled heat dissipation can quickly take away the heat of the capacitor product itself, thereby increasing the product's current capacity.

[0098] The sealing potting material 4 is a potting epoxy resin, which is directly potted into the gap between the housing 3 and the side of the capacitor core 1 to effectively ensure the sealing and oxidation resistance of the product.

[0099] Specifically, the internal extension size of the lead-out copper block 6 is consistent with the inner hole size of the winding mandrel. It is wound on a reel with an inner diameter of 30. The outer diameter of the lead-out copper block 6 is above 50. The resonant current can reach 300-600A (without water cooling) and 800-1200A (with water cooling). The mandrel can be selected according to the size requirements.

[0100] The lead-out copper block 6 is square, and copper nuts 9 are respectively arranged in the middle and around it; wherein, the copper nuts 9 around it are separately arranged and then welded to the lead-out copper block 6, and the copper block in the middle is directly used to form the lead-out copper block 6 at one time, or, the copper nuts 9 around it are directly used to form the lead-out copper block 6 at one time, and the copper nut in the middle is separately arranged and then welded to the lead-out copper block 6. The outer periphery of the copper nut in the middle is equivalent to the size of the mandrel and serves as the welding surface of the end face of the capacitor core 1, and the bottom surface of the copper nut in the middle is milled and flat, and the tapping pattern is processed after the appearance treatment is completed.

[0101] Other parts not described are the same as those in the first embodiment.

[0102] The above is a preferred embodiment of the present invention, which shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may have various changes and improvements without departing from the spirit and scope of the present invention, and these changes and improvements fall within the scope of the present invention to be protected, and the scope of the present invention to be protected is defined by the attached claims and their equivalents.

Claims

1. A high-current axial high-frequency resonant capacitor, comprising a capacitor core (1) and a housing (3), characterized in that: The capacitor core (1) is wound by a double-sided metal film, a single-sided metal film, and an intermediate film (10) arranged between the double-sided metal film and the single-sided metal film, and is provided with a heat conduction hole (23) inside and a gold spraying layer (2) on the surface; the shell (3) is arranged outside the capacitor core (1), and a sealing potting material (4) is also provided between the shells (3); The double-sided metal film comprises a first thin film medium (11), and a double-sided conductive metal layer (12) distributed on both sides of the first thin film medium (11); the double-sided conductive metal layers (12) are provided with double-sided center margins (13) between each other; the single-sided metal film comprises a second thin film medium (14), and a single-sided conductive metal layer (15) distributed on one side of the second thin film medium (14); the single-sided conductive metal layers (15) are provided with single-sided center margins (16) between each other, and a single-sided outer margin (17) is provided on the outer side of the single-sided conductive metal layer (15); the intermediate film (10) is a light film, or the intermediate film (10) is a metal film with the same structure as the single-sided metal film, and the single-sided conductive metal layers (15) of the two are inverted; There are a plurality of double-sided center margins (13); the double-sided conductive metal layer (12) is distributed on both sides of the first thin film medium (11) at equal distances and sizes through a plurality of double-sided center margins (13); or, there is one double-sided center margin (13); the double-sided conductive metal layer (12) is distributed on both sides of the first thin film medium (11) through one double-sided center margin (13); The single-sided conductive metal layer (15) is provided with a single-sided middle margin (16) and a single-sided outer margin (17); a plurality of the single-sided middle margins (16) are provided; the single-sided outer margins (17) are provided on both outer sides of the single-sided conductive metal layer (15); the single-sided conductive metal layer (15) is distributed on a single side of the second thin film medium (14) at equal distances and in equal sizes through the coordination of the plurality of the single-sided middle margins (16) and the single-sided conductive metal layers (15) on both outer sides; the single-sided outer margins (17) are provided on both outer sides of the single-sided conductive metal layer (15), and the single-sided outer margins (17) on both outer sides are provided at the middle position of a single side of the second thin film medium (14); The size of the first thin film medium (11) is larger than or smaller than the size of the second thin film medium (14) and the intermediate film (10); the size of the second thin film medium (14) is the same as the size of the intermediate film (10); the size of the single-sided conductive metal layer (15) is larger than or equal to the size of the double-sided conductive metal layer (12); the size of the double-sided center margin (13) is the same as the size of the single-sided center margin (16); the size of the single-sided center margin (16) is larger than or smaller than the size of the single-sided outer margin (17); The first thin film medium (11) and the second thin film medium (14) are both polypropylene films or polyester films; the double-sided conductive metal layer (12) and the single-sided conductive metal layer (15) are both aluminum-plated layers; The housing (3) is a metal explosion-proof housing, and two of them are provided. The two housings (3) are respectively arranged in an annular manner outside the capacitor core (1), and their end surfaces are flush with each other; the upper and lower ends of the heat conducting hole (23) are respectively provided with lead-out copper blocks (6); The inner side of the lead-out copper block (6) is axially and linearly extended and arranged in the heat conducting hole (23); the outer side of the lead-out copper block (6) is provided with an annular groove (7), and the end surface of the capacitor core (1) and the housing (3) is covered by the annular groove (7); The sealing potting material (4) is poured between the housing (3), the capacitor core (1), and the lead-out copper block (6).

2. A method for manufacturing a high current axial high frequency resonant capacitor, characterized in that: The invention comprises the high current axial high frequency resonant capacitor as claimed in claim 1; wherein the manufacturing method is as follows: Step 1: The double-sided metal film, the intermediate film (10), and the single-sided metal film are stacked in sequence from top to bottom, and then wound by a winding machine to form the cylindrical capacitor core (1); Step 2: spraying the gold spray layer (2) on the capacitor core (1), wherein the gold spray layer (2) is sprayed several times, with zinc spraying twice at the beginning and zinc-tin alloy spraying twice at the end; Step 3: The two shells (3) are respectively placed on the upper and lower outer sides of the capacitor core (1) sprayed with the gold-sprayed layer (2); Step 4: Two lead-out copper blocks (6) are provided, and the annular grooves (7) of the two lead-out copper blocks (6) are provided with a diameter of 1-5 mm and solder paste is applied inside them respectively. The lead-out copper blocks (6) are placed on a heating platform or by means of induction heating, so that all the solder paste is dissolved inside the annular grooves (7); Step 5: Press the upper and lower positions of the capacitor core (1) into the inside of the two annular grooves (7) for 1-7 seconds respectively, so that the two lead-out copper blocks (6) are welded and fixed to the end faces of the capacitor core (1), and then place them in an industrial alcohol box for cooling; Step 6: The two lead copper blocks (6) are respectively provided with holes, one of which is a through hole and the other is a non-through hole, and lead electrodes are provided on the through holes of the lead copper blocks (6), and then the side positions between the housing (3), the capacitor core (1), and the lead copper blocks (6) are sealed and packaged using the sealing potting material (4), so as to finally complete the manufacture of the large current axial high-frequency resonant capacitor.

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