High-temperature polypropylene film capacitor and preparation method thereof

Abstract

The invention discloses a high-temperature polypropylene film capacitor and a preparation method thereof, and particularly relates to the technical field of capacitor production, the capacitor comprises a capacitor main body, the capacitor main body comprises a capacitor inner core, metal conductive layers are formed at two ends of the capacitor inner core through metal spraying processing of a metal spraying machine, and the capacitor inner core is formed by winding an inner core base material. The inner core base material comprises a thin film medium, a metal electrode layer is formed on the thin film medium through evaporation processing, and the thin film medium is prepared by adding an antioxidant and a high-temperature heat stabilizer into polypropylene plastic particles. When the high-temperature polypropylene film capacitor produced by the invention is subjected to metal spraying processing, the coating strip can be tightly attached to the outer wall of the inner core of the capacitor, and adaptive deformation is generated according to the specific shape difference of the outer wall of the inner core of the capacitor, so that the side wall of the inner core of the capacitor can be fully protected during metal spraying, and the service life of the capacitor is prolonged. And the inner core of the capacitor cannot be forcibly extruded, so that the product quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitor production, and more specifically, to a high-temperature polypropylene film capacitor and a preparation method thereof. Background Art

[0002] Film capacitors are capacitors that use polymer films as dielectrics and are widely used in various electronic devices. They are known for their high efficiency, low loss, and good frequency characteristics. Polymer films such as polypropylene (PP), polyester (PET), polystyrene (PS), or polyethylene naphthalate (PEN) are usually used. These materials have high insulation resistance, low dielectric loss, and good self-healing properties. The metal is plated on the dielectric substrate by vacuum evaporation; the capacitor as a whole is wound with two or more metallized films or plain films to form the capacitor core, and then gold is sprayed on both ends of the core to form a metal layer to facilitate welding of leads, and finally encapsulation is performed to obtain a capacitor product.

[0003] With the rapid development of the electronic information industry and the electric power industry, higher requirements are placed on indicators such as the temperature resistance and reliability of film capacitors. Therefore, the production of capacitors will be more strictly controlled in the coming year. Among them, the gold spraying process of capacitors mainly involves arranging the inner core of the capacitor closely on the mounting tray, aligning the gold spraying nozzle with the mounting tray, and controlling the nozzle and the inner core to move slowly relative to each other for gold spraying processing (heating the metal source material to above its melting point until it evaporates, becomes gaseous and sprays toward the end of the inner core, and is deposited on the surface of the end of the inner core to form a metal conductive layer).

[0004] For smaller film capacitors, their inner cores are also relatively small, and can be arranged relatively tightly with relatively small gaps between each inner core. However, for relatively larger capacitors, when their inner cores are arranged by gold spraying, the gaps between each inner core are relatively large. During gold spraying, the material can easily enter the side wall of the inner core through the gap, affecting subsequent processing, especially at the edge of the end face of the inner core. Due to the changes in the relative position and angle of the spray gun and each inner core during movement, the metal layer at the edge of the end of the inner core will be uneven in texture, and it is easy to form a "collapse" phenomenon (similar to chamfering), affecting the quality of the capacitor.

[0005] In the prior art, in order to avoid the above problems, a covering mold is used to clamp and cover the inner core end, exposing only the inner core end face area, thereby effectively limiting the gold spraying area and avoiding spraying onto the inner core side wall, while also ensuring the gold spraying quality of the inner core end edge.

[0006] However, for some cylindrical film capacitors, the inner core is mainly cylindrical in shape formed by winding, and the edge shape is uniform. A fixed arc-shaped coating mold can be simply used, which can almost completely fit the inner core. For some film capacitors, the inner core needs to be hot-pressed (flattened) after winding to make the inner core flat, and a semi-circular arc structure is formed on both sides of the end of the inner core. Due to the limitation of the material of the film capacitor itself, the dimensional accuracy of hot pressing is not high, and the edge contour of the inner core after flattening is not accurate. Therefore, when the coating mold is used to cover and block the outer periphery of the end of the inner core, forced extrusion of some areas or gaps formed by non-contact of some areas will be formed, thereby affecting the restriction effect of the gold-spraying area, especially in the area where forced extrusion is formed. After the gold spraying is completed and the coating mold is removed, the area will release stress and deform, thereby affecting the adhesion quality of the gold-sprayed metal layer in this area and affecting the processing efficiency. Summary of the invention

[0007] The present invention provides a high-temperature polypropylene film capacitor and a preparation method thereof, and aims to solve the problem that when the existing coating mold is adapted to a flattened inner core, coating and shielding the outer periphery of the inner core end will cause forced extrusion of some areas or non-contact of some areas to form gaps, thereby affecting the restriction effect of the gold spraying area and affecting the gold spraying quality of the area.

[0008] To achieve the above object, the present invention provides the following technical solutions: a high-temperature polypropylene film capacitor preparation device, comprising a gold spraying machine, wherein a gold spraying component and a support plate are arranged inside the gold spraying machine, the gold spraying component comprises a gold spraying nozzle, and a plurality of groups of inner core fixing components are arranged on the support plate; Each group of inner core fixing components includes two groups of clamping frames. A clamping driver for controlling the two groups of clamping frames to move closer or farther away from each other is also provided on the support plate. A fixed space is provided between the two groups of clamping frames. A coating strip is provided in the fixed space of each group of clamping frames. The corresponding sides of the fixed spaces in the two groups of clamping frames are open sides. The two ends of the coating strip are respectively connected to the two ends of the open sides of the fixed spaces of the clamping frames, and both ends of the coating strip are connected to the clamping frames through elastic connectors.

[0009] In a preferred embodiment, an end pressing piece is provided at one end of the corresponding opening side in the fixed space of the clamping frame, and a transfer pressing piece is provided at the other end, and the positions of the transfer pressing pieces in one group of clamping frames and the corresponding end pressing pieces in the other group of clamping frames correspond to each other, and the end pressing pieces and the transfer pressing pieces are both connected to the clamping frame through elastic connecting pieces, and a winding shaft is provided at the position of the clamping frame corresponding to the transfer pressing piece, and the winding shaft is rotatably installed in the clamping frame, one end of the coated strip is fixedly connected to the end pressing piece, and the other end of the coated strip bypasses the transfer pressing piece and is fixedly connected to the winding shaft, and a torsional elastic piece is provided between the winding shaft and the clamping frame.

[0010] In a preferred embodiment, a cylindrical support member is provided at a position of the transit pressing member corresponding to the coated strip, the cylindrical support member is rotatably provided on the transit pressing member, the coated strip forms an arc-shaped structure at an outer position of the transit pressing member, and a wedge-shaped filling structure is provided at a position of the end pressing member corresponding to the arc-shaped structure.

[0011] In a preferred embodiment, a filling space is formed between the side of the coating strip facing away from the capacitor core and the clamping frame, and the filling space is filled with filling balls, and the particle diameter of the filling balls is greater than the height difference from the top of the coating strip to the top of the capacitor core.

[0012] In a preferred embodiment, a vibrator is provided on the clamping frame, and the vibrator is fixedly installed on the outside of the clamping frame. A capacity regulator is also provided in the filling space, and the capacity regulator is a plug structure. The capacity regulator is slidably inserted in the side wall of the clamping frame, and one end of the capacity regulator extends into the filling space.

[0013] In a preferred embodiment, the gold spraying component also includes a nozzle driver, which is used to drive the gold spraying nozzle to move. A tray driver is provided in the gold spraying machine, and the tray is installed on the tray driver. The tray driver is used to drive the tray to move, and the moving direction of the tray is perpendicular to the moving direction of the gold spraying nozzle.

[0014] In a preferred embodiment, the clamping driver includes a bidirectional threaded screw, which is rotatably installed in the support plate, and a slider structure is fixedly connected to the bottom of the clamping frame, and the slider structure is slidably arranged in the support plate. The bidirectional threaded screw passes through the slider structure of each group of clamping frames, and the bidirectional threaded screw is respectively provided with a group of threads at the positions of the two groups of clamping frames in each group of inner core fixing components, and the two corresponding groups of threads have opposite rotation directions. The slider structure is threadedly connected to the bidirectional threaded screw through threads, and a screw rotation driver is also arranged on the support plate, and the screw rotation driver is used to drive the bidirectional threaded screw to rotate.

[0015] In a preferred embodiment, the pallet driver is a conveying structure, and a loading port and a unloading port are respectively arranged at both ends of the conveying structure corresponding to the gold spraying machine. The conveying structure is provided with a quick-release structure that is docked with the pallet, and the pallet is detachably connected to the conveying structure through the quick-release structure.

[0016] A high-temperature polypropylene film capacitor comprises a capacitor body, the capacitor body comprises a capacitor core, both ends of the capacitor core are formed with a metal conductive layer by gold spraying with a gold spraying machine, the capacitor core is wound with an inner core substrate, the inner core substrate comprises a film medium, a metal electrode layer is formed on the film medium by evaporation, and the film medium is made by adding an antioxidant and a high-temperature thermal stabilizer to polypropylene plastic particles.

[0017] A method for preparing a high-temperature polypropylene film capacitor comprises the following steps: Step 1: Thin film medium processing: prepare polypropylene plastic particles, add antioxidants and high-temperature heat stabilizers, extrude and mold after melting, and stretch to form a thin film medium; Step 2: Heat treatment of the thin film medium, heating the thin film medium obtained in step 1 and performing annealing treatment; Step 3: preparing the inner core substrate, rolling up and cutting the thin film medium obtained in step 2, and then using a vapor deposition device to vapor-deposit a metal electrode layer on the surface of the cut thin film medium, and then cutting it according to the required size to form an inner core substrate; Step 4: preparing the inner core, winding two inner core substrates face to face together to form a coil, and then hot pressing and shaping the coil through a hot pressing device to form a capacitor inner core, and vacuum drying the capacitor inner core after shaping; Step 5: gold spraying. The capacitor core is placed in two corresponding clamping frames, and the two clamping frames are controlled to be close to each other, so that the coating strip covers the outer wall of the capacitor core and fixes the capacitor core. Then, the gold spraying nozzle is turned on and controlled to move to spray gold on the surface of the end of the capacitor core, so that a metal conductive layer is formed on the end of the capacitor core. Step 6: Welding and packaging: welding leads on the metal conductive layers at both ends of the capacitor core respectively, and then placing the capacitor core in a packaging shell for injection molding to form a thin film capacitor product.

[0018] The beneficial effect of the present invention is that when the high-temperature polypropylene film capacitor produced by the present invention is processed by gold spraying, after the two sets of clamping frames are clamped, the coated strip can be close to the outer wall of the capacitor core, and according to the specific shape difference of the outer wall of the capacitor core, adaptive deformation occurs, thereby ensuring that the side wall of the capacitor core can be fully protected during gold spraying, and no forced extrusion will be generated on the capacitor core, ensuring that the edge of the end of the capacitor core can also form a sufficiently thick and uniform metal conductive layer structure, thereby improving the product quality. In addition, the film dielectric material of this embodiment uses high-purity polypropylene resin as the basic raw material, and adds antioxidants, high-temperature heat stabilizers and other additives according to specific performance requirements, which can effectively improve the performance of the capacitor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the external structure of the gold spraying machine of the present invention.

[0020] Figure 2 It is a schematic diagram of the internal structure of the gold spraying machine of the present invention.

[0021] Figure 3This is a schematic diagram of the structure of the present invention using a conveying device as a pallet driver.

[0022] Figure 4 It is a schematic diagram of the structure of each group of inner core fixing components on the support plate of the present invention.

[0023] Figure 5 It is a schematic diagram of placing the capacitor core into the fixed space in two adjacent groups of clamping frames according to the present invention.

[0024] Figure 6 This is a state diagram of the coating strip and the capacitor core being bonded and coated after the clamping is completed.

[0025] Figure 7 This is a state diagram of the gold spraying nozzle of the present invention when the inner core of the capacitor after coating is subjected to gold spraying treatment.

[0026] Figure 8 It is a schematic diagram of the structure of the improved inner core fixing assembly of the present invention.

[0027] Fig. 9 For the present invention Figure 8 A-section structure enlarged view.

[0028] Fig.10 This is a longitudinal cross-sectional view of the improved inner core fixing assembly of the present invention.

[0029] Fig.11 This is a state diagram of the capacitor core being taken out after the gold spraying is completed.

[0030] Fig.12 It is a schematic diagram of the rebound state of the coating strip after the capacitor core is taken away according to the present invention.

[0031] Fig.13 It is a schematic diagram of the structural composition of the high temperature polypropylene film capacitor of the present invention.

[0032] Fig.14 Schematic diagram of the composition of the inner core substrate of the present invention.

[0033] Fig.15 It is a flow chart of the preparation method of the present invention.

[0034] The accompanying drawings are marked as follows: 1. gold spraying machine; 11. tray drive; 12. loading port; 13. unloading port; 2. gold spraying assembly; 21. gold spraying nozzle; 22. nozzle drive; 3. support plate; 31. clamping drive; 311. bidirectional threaded screw; 312. screw rotation drive; 4. inner core fixing assembly; 41. clamping frame; 411. slider structure; 412. filling space; 413. vibrator; 414. capacity regulator; 42. coated strip; 43. elastic connector; 44. winding shaft; 45. transfer pressing part; 451. columnar support; 46. end pressing part; 47. filling ball; 5. capacitor body; 51. capacitor core; 511. thin film medium; 512. metal electrode layer; 52. metal conductive layer. DETAILED DESCRIPTION

[0035] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0036] Refer to the instruction manual Figures 1 to 12 A high-temperature polypropylene film capacitor preparation device includes a gold spraying machine 1. The gold spraying machine 1 is provided with a gold spraying component 2 and a support plate 3. The gold spraying component 2 includes a gold spraying nozzle 21 and a nozzle driver 22. The nozzle driver 22 is used to drive the gold spraying nozzle 21 to move. The nozzle driver 22 can adopt a single driving device, such as a single linear motor, etc., or a multi-directional driving device can be set according to needs to improve the adequacy of the gold spraying operation. The specific gold spraying operation of the gold spraying nozzle 21 and the mobile driving technology of the gold spraying nozzle 21 are all commonly used solutions in the existing gold spraying process, and will not be explained in detail in this embodiment.

[0037] A plurality of groups of inner core fixing components 4 are arranged on the pallet 3, and the inner core fixing components 4 are used to clamp the capacitor inner core 51. A pallet driver 11 is arranged in the gold spraying machine 1, and the pallet 3 is installed on the pallet driver 11. The pallet driver 11 is used to drive the pallet 3 to move (for example, using a linear motor, a cylinder and other equipment). When the nozzle driver 22 adopts a single-direction drive, the driving direction of the pallet driver 11 to the pallet 3 needs to be perpendicular to the driving direction of the nozzle driver 22 to the gold spraying nozzle 21, so as to ensure that the multiple capacitor inner cores 51 installed on the same pallet 3 are fully sprayed with gold. When the nozzle driver 22 adopts a multi-directional drive, it can ensure that the gold spraying nozzle 21 covers all areas of the pallet 3. In this case, the pallet driver 11 can be selected not to be used, and the pallet 3 and the pallet driver 11 can be connected by a detachable connecting structure such as a socket and bolts, so as to facilitate the removal of the pallet 3 from the gold spraying machine 1 and load and unload multiple capacitor inner cores 51 at the same time.

[0038] Furthermore, each group of inner core fixing components 4 includes two groups of clamping frames 41, and a clamping driver 31 for controlling the two groups of clamping frames 41 to move closer or farther away from each other is also provided on the support plate 3. A fixed space is provided between the two groups of clamping frames 41, and a coating strip 42 is provided in the fixed space of each group of clamping frames 41. The two ends of the coating strip 42 are connected to the edges of the coating space of the clamping frames 41. For details, refer to the attached manual. Figure 5 The corresponding sides of the fixed spaces in the two sets of clamping frames 41 are open sides, and the two ends of the coated strip 42 are respectively connected to the two ends of the open sides of the fixed spaces of the clamping frames 41, and both ends of the coated strip 42 are connected to the clamping frames 41 through elastic connectors 43.

[0039] When in use, the capacitor core 51 is placed between the two corresponding coating strips 42 in the two groups of clamping frames 41. When it needs to be fixed, the two groups of clamping frames 41 are controlled to approach each other and dock, so that the two coating strips 42 contact each other and form a closed coating, which effectively wraps the outer wall of the capacitor core 51. The coating strip 42 can be made of metal thin-walled strips, or plastic parts and other structures. In order to improve the service life, the coating strip 42 in this embodiment is preferably a metal strip. When the capacitor core 51 is placed in the fixed space in the clamping frame 41, the top height of the coating strip 42 is higher than the top height of the capacitor core 51, ensuring sufficient coverage and protection of the capacitor core 51.

[0040] After the inner core fixing assembly 4 has fixed the capacitor inner core 51, the gold spraying nozzle 21 can be used for gold spraying, and the relative movement between the gold spraying nozzle 21 and the support plate 3 can be controlled to fully spray gold on all the capacitor inner cores 51. Since the coating strip 42 in this embodiment has deformable ability, after the two sets of clamping frames 41 are clamped, the coating strip 42 can be tightly attached to the outer wall of the capacitor inner core 51, and according to the specific shape difference of the outer wall of the capacitor inner core 51, adaptive deformation can be generated (when the capacitor inner core 51 is wound, the number of winding turns is fixed, so the circumference of the formed column is fixed. Although the shape changes after hot pressing and some areas produce unknown deformation, its overall circumference remains almost unchanged. Therefore, the length of the coating strip 42 can also be fixed, which is more sufficient during actual fitting). At the same time, an elastic connector 43 is provided between the end of the coating strip 42 and the clamping frame 41, and the joint between the two coating strips 42 can also have relative elastic force, so that the end The coating strip 42 in the area can also fully fit with the capacitor core 51 and produce adaptive changes, thereby ensuring that the side wall of the capacitor core 51 can be fully protected during gold spraying, without forced extrusion of the capacitor core 51, and thus without causing deformation of the capacitor core 51 itself. At the same time, with the help of the coating strip 42 to block the end edge of the capacitor core 51, it can be ensured that a sufficiently thick and uniform metal conductive layer 52 structure can be formed at the end edge of the capacitor core 51. After the gold spraying is completed, when the two groups of clamping frames 41 are controlled to separate, the pressure of the coating strip 42 on the capacitor core 51 is released, the coating strip 42 will produce restorative deformation, and then it will automatically separate from the edge of the capacitor core 51. The capacitor core 51 itself is relatively thin, and the attached metal material formed by the gold spraying on its top is relatively small, and the adhesion is not high. Therefore, during separation, the metal conductive layer 52 at the edge of the capacitor core 51 will hardly be affected, thereby improving product quality.

[0041] Refer to the instruction manual Figure 4 and Figure 7 The clamping driver 31 includes a bidirectional threaded screw 311, which is rotatably installed in the support plate 3. The bottom of the clamping frame 41 is fixedly connected with a slider structure 411, and the slider structure 411 is slidably arranged in the support plate 3. The bidirectional threaded screw 311 passes through the slider structure 411 of each group of clamping frames 41. The bidirectional threaded screw 311 is respectively provided with a group of threads at the positions of the two groups of clamping frames 41 in each group of inner core fixing components 4, and the two corresponding groups of threads have opposite rotation directions. The slider structure 411 is threadedly connected with the bidirectional threaded screw 311 through threads. A screw rotation driver 312 is also provided on the support plate 3. The screw rotation driver 312 is used to drive the bidirectional threaded screw 311 to rotate, thereby controlling the corresponding two groups of clamping frames 41 to approach or move away from each other.

[0042] It should be noted that the above is only one of the driving methods for the clamping frame 41 provided in this embodiment, and all other suitable driving methods can be used in this embodiment. As for the screw rotation driver 312, an automatic device such as a motor can be used to automatically control the bidirectional threaded screw 311. Correspondingly, a power docking structure adapted to the pallet 3 can be provided on the tray driver 11, such as a plug socket, contacts and other structures, to facilitate the disassembly of the pallet 3. At the same time, the screw rotation driver 312 can also adopt a manual control structure such as a knob to manually control the rotation of the bidirectional threaded screw 311. Before the pallet 3 is loaded into the gold spraying machine 1, the clamping frame 41 can be manually controlled to approach each other to clamp the capacitor core 51.

[0043] Among them, in order to improve production efficiency, the gold spraying machine 1 can also be improved into a continuous processing equipment, for example, using the attached figure specification Figure 2 The conveying structure shown (such as a chain conveying structure) acts as a pallet driver 11 to control the movement of the pallet 3, and a loading port 12 and a discharging port 13 are respectively provided on the gold spraying machine 1 for loading and unloading, and a quick-release structure such as a socket is provided between the pallet driver 11 and the pallet 3, so as to realize the movement control of the pallet 3 and the production line transportation at the same time. It should be noted that a closed door structure needs to be provided at the loading port 12 and the discharging port 13 to ensure the processing safety.

[0044] In the above embodiment, the end of the coated strip 42 can be directly fixedly connected to the elastic connector 43. This solution is relatively simple and has a relatively low cost. However, the length of the coated strip 42 formed by this solution is fixed, the size of the capacitor core 51 that can be adapted is fixed, and the length of the coated strip 42 cannot be changed. The actual bonding effect with the capacitor core 51 is relatively poor. For this reason, this embodiment also provides the following technical solutions. For details, refer to the attached manual. Figures 8 to 11, an end pressing piece 46 is provided at one end of the corresponding opening side in the fixed space of the clamping frame 41, and a transfer pressing piece 45 is provided at the other end, and the positions of the transfer pressing pieces 45 in one group of clamping frames 41 and the corresponding end pressing pieces 46 in the other group of clamping frames 41 correspond to each other, and the end pressing pieces 46 and the transfer pressing pieces 45 are both connected to the clamping frame 41 through elastic connecting pieces 43 (the elastic connecting pieces 43 can be made of rubber pads or springs), and a winding shaft 44 is provided at the position corresponding to the transfer pressing piece 45 in the clamping frame 41, and the winding shaft 44 is rotatably installed in the clamping frame 41, one end of the coated strip 42 is fixedly connected to the end pressing piece 46, and the other end of the coated strip 42 bypasses the transfer pressing piece 45 and is fixedly connected to the winding shaft 44, and the winding shaft 44 A torsion elastic member is provided between the clamping frame 41 and the clamping frame 41, and the torsion elastic member is used to provide an elastic force for the winding shaft 44 to wind up the coated strip 42. The transfer pressing member 45 is arranged in a close relationship with the coated strip 42. When the two groups of clamping frames 41 approach and contact each other, the corresponding end pressing members 46 and the transfer pressing members 45 in each group of clamping frames 41 approach each other, and because one end of the coated strip 42 bypasses the transfer pressing member 45, the end pressing member 46 in the other group of clamping frames 41 corresponding to the transfer pressing member 45 is in a close relationship with the part of the coated strip 42 that bypasses the transfer pressing member 45. Since the coated strip 42 at the position that bypasses the transfer pressing member 45 forms an arc-shaped structure, a wedge-shaped filling structure is provided at the position of the end pressing member 46 corresponding to the arc-shaped structure. For details, refer to the attached manual. Fig. 9 , ensuring that after the two sets of covering strips 42 are butt-jointed, a relatively closed structure can still be maintained.

[0045] In actual use, the winding elastic force of the winding shaft 44 on the coating strip 42 is used to make one end of the coating strip 42 have a tensile elastic force, and then under the transfer support of the transfer pressing component 45, the effective length of the coating strip 42 in each group of clamping frames 41 (the actual fitting length with the capacitor core 51) can be adaptively changed, so as to adapt to more capacitor cores 51 (such as cylindrical capacitor cores 51, and other capacitor cores 51 of different sizes). At the same time, the tensile elastic force can make the coating strip 42 fit the surface of the capacitor core 51 more effectively, forming a more effective coverage.

[0046] Especially after the gold spraying is completed, when the capacitor core 51 is taken out, the coated strip 42 will produce more deformation under the elastic force of the winding shaft 44, and the top of the strip 42 may produce bending changes with different curvatures. Fig.12, so that the metal spraying structure formed on the top of the coated strip 42 is easier to fall off, and in order to protect the respective active areas of the transfer pressing member 45, the end pressing member 46 and the winding shaft 44, a thin plate can be set above them to shield and protect them.

[0047] A columnar support member 451 is provided at the position of the transfer pressing member 45 corresponding to the coating strip 42. For structures with limited space, the columnar support member 451 can be a fixed structure directly formed on the transfer pressing member 45. For situations with sufficient space, the columnar support member 451 can be rotatably set on the transfer pressing member 45, thereby reducing the friction loss between the coating strip 42 and the transfer pressing member 45.

[0048] Furthermore, a filling space 412 is formed between the side of the coating strip 42 facing away from the capacitor core 51 and the clamping frame 41, and the filling space 412 is filled with filling balls 47, and the particle diameter of the filling balls 47 is larger than the height difference from the top of the coating strip 42 to the top of the capacitor core 51, wherein the coating strip 42 can be selected from metal ball particles, or other spherical particles such as ceramic ball particles.

[0049] A vibrator 413 is provided on the clamping frame 41. The vibrator 413 is fixedly mounted on the outside of the clamping frame 41 and is used to vibrate the clamping frame 41. It should be noted that in addition to directly setting the vibrator 413 on the clamping frame 41, a group of devices for vibrating the clamping frame 41 can also be separately set, such as a vibration manipulator. The vibrator is installed on the manipulator, and the manipulator drives the vibrator to contact the clamping frame 41 to vibrate the clamping frame 41. However, for ease of operation, the present embodiment preferably sets the vibrator 413 on the clamping frame 41, and the vibrator 413 can be a vibration motor. Regarding the power supply of the vibrator 413, a small battery can be set on the support plate 3, or as mentioned above, a corresponding power supply and control circuit and the corresponding electrical connection docking structure can be set on the loading port 12 to power and control the vibrator 413.

[0050] After the clamping frame 41 clamps the capacitor core 51, the filling balls 47 are put into the filling space 412 and filled to the top area of ​​the coating strip 42. The excess filling balls 47 are scraped off (the particle diameter of the filling balls 47 is larger than the height difference between the top of the coating strip 42 and the top of the capacitor core 51, so it is not easy to stay on the surface of the capacitor core 51). While putting in, the clamping frame 41 with the vibrator 413 vibrates, thereby making the filling balls 47 compact. At the same time, the granular filling balls 47 are on the coating strip 42. The outer wall forms a sufficient squeeze on the filling ball 47. Therefore, even if there is a slight depression on the side wall surface of the capacitor core 51, the pressure of the filling ball 47 can make the coating strip 42 produce adaptive deformation and fit the capacitor core 51 (mainly for the top area, to ensure that no gap is formed between the coating strip 42 and the top area of ​​the capacitor core 51). Since no gap is formed, when gold is sprayed, no metal connection structure is formed between the coating strip 42 and the side wall of the capacitor core 51, which is easier to separate later.

[0051] It should be noted that due to the presence of the filling balls 47, the empty space between the coating strip 42 and the clamping frame 41 is filled. Therefore, the filling balls 47 on the top layer can receive the gold-sprayed material so that the gold-sprayed material will not fall into the space between the clamping frame 41 and the coating strip 42. Moreover, after the gold spraying is completed, before the two sets of clamping frames 41 are separated, the vibrator 413 can be controlled to vibrate again, thereby making the internal filling balls 47 move. On the one hand, the filling balls 47 forming the metal layer on the top can be relatively separated to break the metal layer in this area. On the other hand, the vibration of the filling balls 47 can also be transmitted to the contact area between the coating strip 42 and the top edge of the capacitor core 51, so that the edge of the metal layer in the area is broken, making it easier to separate from the coating strip 42.

[0052] For further information, please refer to the attached manual. Fig.10 and Fig.11 A capacity regulator 414 is also provided in the filling space 412. The capacity regulator 414 is used to adjust the volume of the filling space 412. Specifically, the capacity regulator 414 is a plug structure. The capacity regulator 414 is slidably inserted in the side wall of the clamping frame 41, and one end of the capacity regulator 414 extends into the filling space 412.

[0053] Before filling the filling ball 47, the capacity regulator 414 can be inserted into the filling space 412. When the gold spraying is completed and the capacitor core 51 needs to be removed, the vibrator 413 is controlled to vibrate first, and then the capacity regulator 414 is controlled to move out of the filling space 412. At this time, refer to the attached manual. Fig.11The internal space of the filling space 412 increases, and the filling ball 47 will sink relatively, thereby increasing the movement amplitude of the filling ball 47. At the same time, the metal layer structure formed on the top of the filling ball 47 and the top of the coating strip 42 will also be more fully separated due to the sinking of the filling ball 47, thereby improving the separation effect of the metal conductive layer 52 on the top of the capacitor core 51 and the redundant metal layer structure, and further improving the product quality.

[0054] It should be noted that the above plug structure is only one of the space control solutions provided in this embodiment. In addition, a structure similar to an airbag can also be used for control, and it is only necessary to ensure that the filling ball 47 can be controlled to sink.

[0055] It should be noted that the existing film capacitors are mainly polyester film and polypropylene film capacitors. Although polyester capacitors have a higher temperature resistance coefficient, they are not suitable for use in high-frequency and high-current circuits due to their large high-frequency losses. Conventional polypropylene film capacitors have good high-frequency characteristics and are suitable for use in high-frequency and high-current circuits. However, polypropylene film capacitors have temperature resistance differences and are not suitable for working at higher ambient temperatures. For example, as the working time of polypropylene capacitors used in such high-temperature ambient temperatures increases, their internal temperature rises rapidly, resulting in a sharp drop in the stability of the capacitor, and even causing the capacitor to fail, posing serious safety hazards to electronic equipment and power grids.

[0056] To this end, this embodiment, based on the premise of improving the quality of gold spraying, also provides a high-temperature polypropylene film capacitor with better performance. Fig.13 and Fig.14 , including a capacitor body 5, the capacitor body 5 includes a capacitor core 51, both ends of the capacitor core 51 are formed with a metal conductive layer 52 by gold spraying by a gold spraying machine 1, and the capacitor core 51 is wound by an inner core substrate, wherein, refer to the attached specification Fig.14 The inner core substrate includes a thin film medium 511, on which a metal electrode layer 512 is formed by vapor deposition. The thin film medium 511 is made of high-purity polypropylene plastic particles, antioxidants and high-temperature thermal stabilizers, mixed and melted, extruded, and stretched.

[0057] It should be noted that antioxidants and high-temperature heat stabilizers are commonly used plastic price preparations, so their specific components are not explained in detail in this embodiment.

[0058] In addition, in order to comprehensively improve the quality of film capacitors, based on the above-mentioned preparation device, this embodiment also provides a preparation method of high-temperature polypropylene film capacitors, refer to the attached manual Fig.15 , including the following steps: Step 1, processing the film medium 511, preparing high-purity polypropylene plastic particles, adding antioxidants and high-temperature heat stabilizers, extruding and stretching after melting to form the film medium 511, wherein Nordic polypropylene 310 plastic particles (traditional basic material polypropylene plastic particles model 303) are used, the raw materials are put into an extruder, heated to 200°C-250°C to melt it, and the molten polypropylene is extruded into a sheet by the rotation of the screw, and then the extruded sheet polypropylene is biaxially stretched in the longitudinal and transverse directions to orient the molecular chains along the stretching direction to improve the performance of the film; Step 2: heat treatment of the thin film medium 511: heating the thin film medium 511 obtained in step 1 to 120° C.-150° C. and performing annealing treatment; Step 3: preparing the inner core substrate, rolling up and cutting the thin film medium 511 obtained in step 2, and then using a vapor deposition device to vapor-deposit the cut thin film medium 511 on the surface of the thin film medium 511 to form a metal electrode layer 512, and then cutting it according to the required size to form an inner core substrate; Step 4: preparing the inner core. Two inner core substrates are wound together face to face to form a coil, and then hot-pressed and shaped by a hot-pressing device to form a capacitor inner core 51. After shaping, the capacitor inner core 51 is vacuum dried at a drying temperature of 130° C. for 4 hours. Step 5: gold spraying. The capacitor core 51 is placed in the two corresponding clamping frames 41, and the two clamping frames 41 are controlled to be close to each other, so that the coating strip 42 covers the outer wall of the capacitor core 51 and fixes the capacitor core 51. Then, the gold spraying nozzle 21 is turned on and controlled to move to fully spray the surface of the end of the capacitor core 51, so that a metal conductive layer 52 is formed on the end of the capacitor core 51. Step 6: Welding and packaging: welding leads on the metal conductive layer 52 at both ends of the capacitor core 51 respectively, and then placing the capacitor core 51 in a packaging shell for injection molding to form a thin film capacitor product. After the test is completed, it can be packaged.

[0059] Among them, the thin film dielectric material 511 of this embodiment uses high-purity polypropylene resin as the basic raw material, and adds antioxidants, high-temperature heat stabilizers and other additives according to specific performance requirements to improve the high temperature resistance and processing characteristics of the polypropylene thin film dielectric material 511. The high-temperature polypropylene thin film dielectric 511 used in this embodiment is not easy to soften or decompose in a high temperature environment, ensuring the capacitor structure and electrical performance, thereby enabling the capacitor structure to have extremely low dielectric loss in a high temperature environment, effectively reducing energy loss and heat generation, and having high insulation resistance, effectively preventing leakage, and ensuring the safe operation of the capacitor in a high temperature and high voltage environment. At the same time, the capacitance stability is excellent, and is less affected by temperature, providing a stable capacitance value for the circuit. In addition, since the thin film dielectric 511 undergoes effective heat treatment during production, it has good mechanical properties, has certain flexibility and tensile strength under high temperature conditions, and is not easy to crack.

[0060] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A high-temperature polypropylene film capacitor manufacturing device, comprising a gold spraying machine (1), wherein the gold spraying machine (1) is provided with a gold spraying component (2) and a support plate (3), wherein the gold spraying component (2) comprises a gold spraying nozzle (21), characterized in that: The support plate (3) is provided with a plurality of groups of inner core fixing components (4); Each group of the inner core fixing components (4) comprises two groups of clamping frames (41). The support plate (3) is also provided with a clamping driver (31) for controlling the two groups of the clamping frames (41) to move closer to or farther from each other. A fixed space is provided between the two groups of the clamping frames (41). A coating strip (42) is provided in the fixed space of each group of the clamping frames (41). The corresponding sides of the fixed spaces in the two groups of the clamping frames (41) are open sides. The two ends of the coating strip (42) are respectively connected to the two ends of the open side of the fixed space of the clamping frames (41), and the two ends of the coating strip (42) are connected to the clamping frames (41) via elastic connectors (43).

2. A high temperature polypropylene film capacitor preparation device according to claim 1, characterized in that: An end pressing member (46) is provided at one end of the corresponding opening side in the fixed space of the clamping frame (41), and a transfer pressing member (45) is provided at the other end, and the positions of the transfer pressing members (45) in one group of clamping frames (41) and the end pressing members (46) in the corresponding other group of clamping frames (41) correspond to each other, and the end pressing members (46) and the transfer pressing members (45) are both connected to the clamping frame (41) via an elastic connecting member (43). A winding shaft (44) is provided at a position in the frame (41) corresponding to the transfer pressing member (45), and the winding shaft (44) is rotatably mounted in the clamping frame (41). One end of the coated strip (42) is fixedly connected to the end pressing member (46), and the other end of the coated strip (42) bypasses the transfer pressing member (45) and is fixedly connected to the winding shaft (44). A torsional elastic member is provided between the winding shaft (44) and the clamping frame (41).

3. A high temperature polypropylene film capacitor preparation device according to claim 2, characterized in that: A columnar support member (451) is provided at a position of the transfer pressing member (45) corresponding to the coating strip (42); the columnar support member (451) is rotatably provided on the transfer pressing member (45); the coating strip (42) forms an arc-shaped structure at an outer position of the transfer pressing member (45); and a wedge-shaped filling structure is provided at a position of the end pressing member (46) corresponding to the arc-shaped structure.

4. A high temperature polypropylene film capacitor preparation device according to claim 3, characterized in that: A filling space (412) is formed between the side of the coating strip (42) facing away from the capacitor core (51) and the clamping frame (41), and the filling space (412) is filled with filling balls (47), and the particle diameter of the filling balls (47) is greater than the height difference between the top of the coating strip (42) and the top of the capacitor core (51).

5. The high temperature polypropylene film capacitor preparation device according to claim 4, characterized in that: A vibrator (413) is provided on the clamping frame (41), and the vibrator (413) is fixedly mounted on the outside of the clamping frame (41). A capacity regulator (414) is also provided in the filling space (412), and the capacity regulator (414) is a plug structure. The capacity regulator (414) is slidably inserted in the side wall of the clamping frame (41), and one end of the capacity regulator (414) extends into the filling space (412).

6. A high temperature polypropylene film capacitor preparation device according to claim 5, characterized in that: The gold spraying assembly (2) further comprises a nozzle driver (22), wherein the nozzle driver (22) is used to drive the gold spraying nozzle (21) to move. The gold spraying machine (1) is provided with a tray driver (11), wherein the tray (3) is mounted on the tray driver (11), wherein the tray driver (11) is used to drive the tray (3) to move, and wherein the moving direction of the tray (3) is perpendicular to the moving direction of the gold spraying nozzle (21).

7. A high temperature polypropylene film capacitor preparation device according to claim 6, characterized in that: The clamping driver (31) comprises a bidirectional threaded screw (311), the bidirectional threaded screw (311) being rotatably mounted in the support plate (3), the bottom of the clamping frame (41) being fixedly connected to a slider structure (411), the slider structure (411) being slidably mounted in the support plate (3), the bidirectional threaded screw (311) passing through the slider structure (411) of each group of clamping frames (41), the bidirectional threaded screw (311) being respectively provided with a group of threads at positions corresponding to the two groups of clamping frames (41) in each group of inner core fixing components (4), and the two groups of threads corresponding to each other having opposite rotation directions, the slider structure (411) being threadedly connected to the bidirectional threaded screw (311) via threads, and the support plate (3) is also provided with a screw rotation driver (312), the screw rotation driver (312) being used to drive the bidirectional threaded screw (311) to rotate.

8. The high temperature polypropylene film capacitor preparation device according to claim 7, characterized in that: The tray driver (11) is a conveying structure. A loading port (12) and a discharging port (13) are respectively arranged at two ends of the conveying structure corresponding to the gold spraying machine (1). The conveying structure is provided with a quick-release structure that is mutually docked with the support plate (3). The support plate (3) is detachably connected to the conveying structure via the quick-release structure.

9. A high temperature polypropylene film capacitor prepared by the preparation device according to claim 8, characterized in that: The invention comprises a capacitor body (5), wherein the capacitor body (5) comprises a capacitor core (51), and metal conductive layers (52) are formed at both ends of the capacitor core (51) by gold spraying with a gold spraying machine (1), wherein the capacitor core (51) is wound by an inner core substrate, wherein the inner core substrate comprises a thin film medium (511), and a metal electrode layer (512) is formed on the thin film medium (511) by vapor deposition, and wherein the thin film medium (511) is made by adding an antioxidant and a high-temperature heat stabilizer to polypropylene plastic particles.

10. A method for preparing the high temperature polypropylene film capacitor according to claim 9, characterized in that: The following steps are involved: Step 1: Processing of the film medium (511): preparing polypropylene plastic particles, adding an antioxidant and a high-temperature heat stabilizer, extruding and molding the particles after melting, and stretching the particles to form the film medium (511); Step 2: heat treatment of the thin film medium (511), heating the thin film medium (511) obtained in step 1 and performing annealing treatment; Step 3: preparing the inner core substrate, rolling up and cutting the thin film medium (511) obtained in step 2, and then using a vapor deposition device to vapor-deposit the cut thin film medium (511) on the surface of the thin film medium (511) to form a metal electrode layer (512), and then cutting it into desired sizes to form an inner core substrate; Step 4, preparing the inner core, winding two inner core substrates face to face together to form a coil, and then performing heat pressing and shaping by a hot pressing device to form a capacitor inner core (51), and after shaping, vacuum drying the capacitor inner core (51); Step 5: performing gold spraying, placing the capacitor core (51) in two corresponding sets of clamping frames (41), and controlling the two sets of clamping frames (41) to approach each other, so that the coating strip (42) coats the outer wall of the capacitor core (51) and fixes the capacitor core (51), and then starting and controlling the gold spraying nozzle (21), and controlling the gold spraying nozzle (21) to move to perform gold spraying on the end surface of the capacitor core (51), so that a metal conductive layer (52) is formed on the end of the capacitor core (51); Step six, welding packaging, welding leads on the metal conductive layers (52) at both ends of the capacitor core (51) respectively, and then placing the capacitor core (51) in a packaging shell for injection molding packaging to form a thin film capacitor product.

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