Filling and sealing tool for shell-less surface-mounted film capacitor

Abstract

The embedding tool comprises an upper shell, a lower shell and a connecting bolt, the middle part of the upper shell is provided with an upper shell inner cavity with an opening at the lower part, the middle parts of the cavity walls at the two ends of the upper shell inner cavity are respectively provided with a convex positioning boss, the middle part of the lower shell is provided with a lower shell inner cavity with an opening at the upper part, and the upper part of the lower shell is provided with a convex positioning boss. Glue injection through holes are formed in the positions, close to the four corners, of the bottom of the inner cavity of the lower shell respectively, and concave positioning grooves are formed in the positions, close to the middles of the two ends, of the bottom of the inner cavity of the lower shell respectively. The upper shell and the lower shell which are matched with each other are designed, positioning bosses are arranged in the middles of the cavity walls of the two ends of the inner cavity of the upper shell respectively, positioning grooves are formed in the positions, close to the middles of the two ends, of the bottom of the inner cavity of the lower shell respectively, and glue injection through holes are formed in the positions, close to the four corners, of the bottom of the inner cavity of the lower shell respectively. And finally, reliable positioning and integral potting functions of the shell-free surface-mounted thin film capacitor are realized.

Description

Technical Field

[0001] This utility model relates to a potting fixture for film capacitors, and more particularly to a potting fixture for caseless surface-mount film capacitors. Background Technology

[0002] Organic thin-film capacitors are capacitors made using organic thin-film materials as the dielectric. They have advantages such as small size, light weight, and low cost. Due to their excellent properties such as self-healing characteristics, open-circuit failure mode, and stable temperature characteristics, they are widely used in military weaponry. However, in recent years, with the development needs of miniaturization and lightweight military weaponry, new requirements have been placed on the small size, large capacity, and lightweight of components.

[0003] Surface-mount film capacitors, also known as chip film capacitors, are organic film capacitors that use chip electrodes (usually "L" shaped). These capacitors can fit more tightly to the circuit board during installation, resulting in a smaller installation volume, which is beneficial for product miniaturization and weight reduction.

[0004] Specific capacitance is an important indicator of a capacitor. The higher the value, the greater the amount of electricity that the capacitor can store for the same volume or mass, or the smaller the volume or mass of the capacitor corresponding to the same amount of electricity storage. Therefore, in applications requiring small size, large capacity, and lightweight design, the higher the specific capacitance of surface-mount film capacitors, the better.

[0005] Traditional surface-mount film capacitors are encapsulated using a casing (usually an insulating plastic casing) and sealant (usually epoxy resin). To improve specific capacitance, without changing the capacitor core, the only way is to reduce the thickness of the casing and the sealant. However, reducing the sealant thickness reduces the insulation and sealing effect, including reducing the product's insulation, flame retardancy, and vibration resistance. Moreover, regardless of how the casing and sealant thickness are reduced, the thickness of the capacitor core remains the same as the total thickness of the casing and insulating sealant. Therefore, it is difficult to further improve the specific capacitance of traditional surface-mount film capacitors while ensuring reliable performance. In addition, before potting the sealant inside the casing, positioning fixtures are needed to position the capacitor core so that it is centered in the casing. This not only increases the manufacturing difficulty but also increases the capacitor size by providing installation space for the positioning fixtures.

[0006] To solve the above problems, the following methods can be adopted: Figures 1-4The illustrated type is a caseless surface-mount film capacitor, comprising a capacitor core 11, surface-mount electrodes 1, sealant 2, an insulating annular reinforcing plate 13, and welded metal sheets 3. Two core metal plates 8 are respectively provided at both ends of the capacitor core 11, and the two surface-mount electrodes 1 are respectively connected to the two core metal plates 8. The annular reinforcing plate 13 is placed outside the capacitor core 11, with its inner walls at both ends in close contact with the outer walls of the core metal plates 8 at both ends of the capacitor core 11. The inner walls of opposite sides of the annular reinforcing plate 13 are respectively in close contact with the opposite sides of the outer walls of the capacitor core 11. Reinforcing plate through holes 10 are respectively provided at both ends of the annular reinforcing plate 13. The two welded metal sheets 3 are... Located on the outer sides of both ends of the annular reinforcing plate 13, the welding metal sheet 3 is welded to the corresponding core metal plate 8, and the connection part is located in the corresponding reinforcing plate through hole 10. The middle section of the welding metal sheet 3 is recessed towards the corresponding core metal plate 8 and placed in the corresponding reinforcing plate through hole 10, and a metal sheet groove 6 is formed on the outer wall of the middle section of the welding metal sheet 3. One end of the "L"-shaped plate electrode 1 is located in the corresponding metal sheet groove 6. Both ends of the welding metal sheet 3 are bent towards the opposite core metal plate 8 to form metal plate end plates 4. The metal plate end plates 4 are in contact with the corresponding opposite outer walls on the annular reinforcing plate 13. The outer wall of the metal plate end plate 4 is thinned to form a reinforcing plate groove 12. The inner wall of the metal plate end plate 4 near the suspended end is thinned to form an end plate thinning section 5. The end plate thinning section 5 is placed in the corresponding reinforcing plate groove 12 so that the outer wall surface of the metal plate end plate 4 is flush with the corresponding outer wall surfaces on the opposite sides of the annular reinforcing plate 13. The middle section of the welding metal sheet 3 is provided with multiple spaced welding grooves 7 near one edge. The welding grooves 7 are provided with solder for welding to the corresponding core metal plate 8. The welding metal sheet 3 is integrally formed with the plate electrode 1. The sealant 2 covers the capacitor core 11, the annular reinforcing plate 13 and the welding metal sheet 3 but does not cover the outer wall of the plate electrode 1. On the surface, the sheet electrode 1 has a sandwich space 9 filled with sealant 2. The annular reinforcing plate 13 has multiple potting through holes on opposite sides, and the potting through holes are filled with sealant 2. The potting through holes include a first potting through hole 14 and a second potting through hole 15. The center line of the first potting through hole 14 and the center line of the second potting through hole 15 have an angle of 10°-60° with the opposite side surfaces of the annular reinforcing plate 13. The center line of the first potting through hole 14 and the center line of the second potting through hole 15 have an angle of 20°-120°. The multiple first potting through holes 14 and the multiple second potting through holes 15 are arranged alternately.

[0007] The above are as follows Figures 1-4The caseless surface-mount film capacitor shown requires the capacitor core 11, the annular reinforcing plate 13, and the welded metal sheet 3 to be encapsulated with sealant 2. Furthermore, the corresponding components need to be reliably positioned before encapsulation. Traditional capacitor encapsulation fixtures cannot achieve this function, so a new encapsulation fixture is needed to solve this problem. Utility Model Content

[0008] The purpose of this invention is to provide a potting fixture for caseless surface-mount film capacitors in order to solve the above-mentioned problems.

[0009] This utility model achieves the above objectives through the following technical solutions:

[0010] A potting fixture for a caseless surface-mount film capacitor includes an upper shell, a lower shell, and connecting bolts. The upper shell has connecting screw holes near its four corners, and the lower shell has connecting through holes near its four corners. Four connecting bolts pass through the four connecting through holes from bottom to top and connect to the four connecting screw holes. The upper shell has a lower-opening inner cavity in its middle section, and protruding positioning bosses are provided at the middle of the cavity walls at both ends. The lower shell has an upper-opening inner cavity in its middle section, and injection through holes are provided at the four corners of the bottom of the lower shell inner cavity. Recessed positioning grooves are provided at the middle of the bottom of the lower shell inner cavity at both ends.

[0011] Preferably, in order to facilitate precise alignment and connection of the upper and lower housings, the upper housing is provided with a downwardly protruding annular boss near the inner cavity of the upper housing, and the lower housing is provided with a concave annular groove near the inner cavity of the lower housing, with the annular boss located within the annular groove.

[0012] Preferably, in order to facilitate quick separation of the upper and lower shells, the lower shell has an upper wedge-shaped groove with an outer opening at the lower part near the middle of both ends, and the lower shell has a lower wedge-shaped groove with an outer opening at the upper part near the middle of both ends, with the two upper wedge-shaped grooves located above the two lower wedge-shaped grooves respectively.

[0013] The beneficial effects of this utility model are as follows:

[0014] This invention designs a cooperating upper and lower housing. Positioning bosses are provided at the midpoints of the inner walls at both ends of the upper housing cavity, and positioning grooves are provided at the bottom of the lower housing cavity near the midpoints of both ends. This allows for reliable positioning of the metal plate recesses and plate electrodes of the caseless surface-mount film capacitor. Furthermore, injection holes are provided at the four corners of the bottom of the lower housing cavity. Sealant is injected through two injection holes, and vented through the other two, ultimately achieving reliable positioning and overall potting of the caseless surface-mount film capacitor. Attached Figure Description

[0015] Figure 1 This is one of the three-dimensional views of the assembled shell-less surface-mount film capacitor described in this utility model, showing the product on top.

[0016] Figure 2 This is the second perspective view of the assembled shell-less surface-mount film capacitor described in this utility model, showing the bottom of the product.

[0017] Figure 3 This is a three-dimensional exploded view of the shell-less surface-mount film capacitor described in this utility model before assembly and after the sealant has been removed. The perspective in the view is... Figure 1 Consistent;

[0018] Figure 4 This is a perspective view of the assembled, sealant-free surface-mount thin-film capacitor described in this utility model. The perspective in the figure is... Figure 1 Consistent;

[0019] Figure 5 This is a perspective view of the potting fixture for the shell-less surface-mount film capacitor described in this utility model before assembly.

[0020] Figure 6 This is a perspective view of the upper housing of the potting fixture for a caseless surface-mount film capacitor as described in this utility model. The perspective in the figure is... Figure 5 different;

[0021] Figure 7 This is a perspective view of the potting fixture for the shell-less surface-mount film capacitor described in this utility model before assembly during use. The perspective in the figure is... Figure 5 same;

[0022] Figure 8 This is a semi-sectional perspective view of the potting fixture for shell-less surface-mount capacitors described in this utility model after assembly during use. The viewpoint is... Figure 5 and Figure 7 same;

[0023] Figure 9This is a perspective view of the encapsulation fixture for caseless surface-mount film capacitors described in this utility model after assembly during use. The perspective in the figure is... Figure 6 same. Detailed Implementation

[0024] The present invention will be further described below with reference to the accompanying drawings:

[0025] like Figure 5 and Figure 6 As shown, the potting fixture for shell-less surface-mount film capacitors of this utility model includes an upper shell 16, a lower shell 20, and connecting bolts 22. The upper shell 16 is provided with connecting screw holes 27 near the four corners, and the lower shell 20 is provided with connecting through holes 18 near the four corners. The four connecting bolts 22 pass through the four connecting through holes 18 from bottom to top and are connected to the four connecting screw holes 27. The upper shell 16 is provided with an upper shell cavity 29 with a lower opening in the middle. The upper shell cavity 29 is provided with a protruding positioning boss 28 in the middle of the cavity walls at both ends. The lower shell 20 is provided with a lower shell cavity 23 with an upper opening in the middle. The lower shell cavity 23 is provided with glue injection through holes 25 near the four corners at the bottom of the cavity, and the lower shell cavity 23 is provided with recessed positioning grooves 26 near the middle of both ends at the bottom of the cavity.

[0026] Preferably, to facilitate precise alignment and connection of the upper housing 16 and the lower housing 20, the upper housing 16 is provided with a downwardly protruding annular boss 24 near the inner cavity 29 of the upper housing, and the lower housing 20 is provided with a concave annular groove 21 near the inner cavity 23 of the lower housing, with the annular boss 24 located within the annular groove 21; to facilitate quick separation of the upper housing 16 and the lower housing 20, the lower housing 16 is provided with an upper wedge-shaped groove 17 with an outer opening near the middle of both ends on the lower side, and the lower housing 20 is provided with a lower wedge-shaped groove 19 with an outer opening near the middle of both ends on the upper side, with the two upper wedge-shaped grooves 17 located above the two lower wedge-shaped grooves 19 respectively.

[0027] like Figures 1-9As shown, before potting, the capacitor core 11, the plate electrode 1, the annular reinforcing plate 13, and the welding metal sheet 3 are assembled together according to the above structure, and the plate electrode 1 is welded to the core metal plates 8 at both ends of the capacitor core 11. At this time, all components of the capacitor except for the sealant 2 are stably or substantially stably connected together to form the pre-potting assembly. Then, the pre-potting assembly is placed inside the lower housing cavity 23 of the lower housing 20, so that the bottoms of the two plate electrodes 1 are respectively placed in the two positioning grooves 26. Then, the upper housing 16 is installed on the pre-potting assembly from top to bottom, so that the two positioning protrusions 28 of the upper housing 16 are respectively placed in the two positioning grooves 26. Before potting, the four connecting bolts 22 are inserted into the two metal plate recesses 6 at both ends of the component. Then, the four connecting bolts 22 are passed through the four connecting through holes 18 from bottom to top and connected to the four connecting screw holes 27. This completes the purpose of positioning and installing the component before potting through the potting mold. Then, the potting mold is flipped so that the four injection through holes 25 face upward. Liquid sealant 2 is injected through two of the injection through holes 25, and the other two injection through holes 25 are used for venting. After filling, wait for the sealant 2 to cure. After curing, the potting mold is flipped again, the four connecting bolts 22 are removed, the upper shell 16 is removed, the product is taken out, and after polishing, the shell-less surface-mount film capacitor is obtained.

[0028] The above embodiments are merely preferred embodiments of this utility model and are not intended to limit the technical solutions of this utility model. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of this utility model patent.

Claims

1. A potting fixture for a caseless surface-mount film capacitor, comprising an upper housing, a lower housing, and connecting bolts, wherein the upper housing has connecting screw holes near its four corners, and the lower housing has connecting through holes near its four corners; the four connecting bolts pass through the four connecting through holes from bottom to top and are connected to the four connecting screw holes, characterized in that: The upper shell has a lower opening in the middle, and the inner cavity of the upper shell has protruding positioning bosses in the middle of the cavity walls at both ends. The lower shell has an upper opening in the middle, and the bottom of the inner cavity of the lower shell has glue injection holes near the four corners. The bottom of the inner cavity of the lower shell has recessed positioning grooves near the middle of both ends.

2. The potting fixture for caseless surface-mount film capacitors according to claim 1, characterized in that: The upper housing has a downwardly protruding annular boss near the inner cavity of the upper housing, and the lower housing has a concave annular groove near the inner cavity of the lower housing, with the annular boss located within the annular groove.

3. The potting fixture for caseless surface-mount film capacitors according to claim 1 or 2, characterized in that: The upper shell has an upper wedge-shaped groove with an outer opening at the lower part near the middle of both ends, and the lower shell has a lower wedge-shaped groove with an outer opening at the upper part near the middle of both ends. The two upper wedge-shaped grooves are respectively located on the upper part of the two lower wedge-shaped grooves.

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