Dipping process for thin-film capacitor element

Abstract

The invention discloses a thin film capacitor element impregnation technology. The technology comprises the following steps of element preparation, impregnation preparation, element preheating, element impregnation, inspection and element unloading. And the temperature and time of partial procedures are stipulated. The method is suitable for processing the end face of the thin-film capacitor element, the electrical performance of the thin-film capacitor element is not affected, and the production efficiency of products is improved in the aspect of operation.

Description

Technical Field

[0001] The invention relates to the field of capacitor manufacturing, and in particular to a film capacitor element impregnation process. Background Art

[0002] Film capacitors are key components of converters, and they play a role in stabilizing voltage and filtering on the DC side of converters. At present, high-voltage and large-capacity film capacitors are required in converters such as high-voltage inverters, high-speed train converters, high-power STATCOMs, and converter valves for flexible DC transmission projects. Film capacitors, as energy storage devices, are also widely used in pulse power supplies.

[0003] These film capacitors are metallized polypropylene film capacitors, and their structures are generally divided into dry structure and oil-immersed structure.

[0004] Dry-type film capacitors are usually vacuum-cast polyurethane, and the weight of the cast polyurethane accounts for about 25% of the weight of the capacitor. Oil-immersed film capacitors are usually vacuum-impregnated with silicone oil or vegetable oil, and the weight of the impregnated oil also accounts for about 25% of the weight of the capacitor. Polyurethane or impregnated oil mainly plays the role of insulation and heat dissipation in film capacitors.

[0005] In special occasions, film capacitors need to control the weight and size of capacitors. The above two types of capacitors are relatively heavy, and the vacuum casting polyurethane and vacuum impregnation oil processes in the production process are no longer suitable for this type of capacitor.

[0006] The element of the film capacitor is two layers of metallized polypropylene film wound on a mandrel, and then metal material is sprayed on both ends as electrodes. If the end surface of the element is in contact with the air for a long time, it will affect the electrical performance of the element. Therefore, it is necessary to have a processing process for the film capacitor element to ensure that the electrical performance of the film capacitor element is not affected. Summary of the invention

[0007] In order to solve the above problems, the present invention provides an impregnation process for a film capacitor element (hereinafter referred to as “element”).

[0008] The technical solution adopted by the present invention is as follows.

[0009] The component impregnation process includes the following steps: (1) Component preparation: The components are primed with solder, and a constant temperature soldering iron is used, with a temperature of 450-480 degrees and a soldering point diameter of 6 mm²; the components are placed horizontally in a wire frame and arranged neatly, and then pushed into the work area with a trolley; (2) Dipping preparation: Place the wax dipping tank in an oven, turn on the oven and adjust the heating temperature to 90°C, start the oven and run it until the wax in the wax tank is completely melted and the wax temperature rises to 90°C, and maintain it for 4 hours; (3) Component preheating: Place the components in the wire frame together with the wire frame in a 95°C oven, heat for 3 hours, take them out, put them in a vacuum tank, and evacuate the vacuum to 10Pa, maintain for 0.5 hours, and take them out for use; (4) Component dipping: Place the wire frame with components in the wax box. During the wax dipping process, the wax temperature must be kept constant at 90°C. The wax dipping time is 15 minutes. Take out the wire frame with components and drip wax in an oven for 15 minutes. The oven temperature is maintained at 95°C. (5) Inspection: The components are fully wetted and wax-impregnated evenly; (6) Component unloading: Take out the components, wipe them with a clean cloth, and put them into the turnover box; Among them, the deviation of the above temperatures can be within ±2%, and the deviation of each time can be within ±5%.

[0010] Furthermore, the melting point of the paraffin wax used is 80°C.

[0011] Furthermore, the metallized film of the film capacitor is resistant to high temperatures, ranging from 95 to 105°C; excessively high wax temperatures will cause the film to expand, and the wax temperature is controlled at 90°C.

[0012] Furthermore, operators need to wear gloves and long-sleeved and long-trouser work clothes.

[0013] Furthermore, operators should concentrate when working, handle components with care, and ensure that components are fully cooled after operation.

[0014] Furthermore, the temperature of the vacuum tank and oven must be maintained and must not be adjusted at will.

[0015] The beneficial effects of the present invention are: According to the material temperature characteristics of the film capacitor element, the above method can be used to effectively process the end surface of the film capacitor element without affecting the electrical properties of the film capacitor element, thereby improving the operation and production efficiency of the product. DETAILED DESCRIPTION

[0016] The following specific examples further illustrate the present invention. This process includes the following steps: (1) Component preparation: The components are primed with solder, and a constant temperature soldering iron is used, with a temperature of 450-480 degrees and a soldering point diameter of 6 mm²; the components are placed horizontally in a wire frame and arranged neatly, and then pushed into the work area with a trolley; (2) Dipping preparation: Place the wax dipping tank in an oven, turn on the oven and adjust the heating temperature to 90°C, start the oven and run it until the wax in the wax tank is completely melted and the wax temperature rises to 90°C, and maintain it for 4 hours; (3) Component preheating: Place the components in the wire frame together with the wire frame in a 95°C oven, heat for 3 hours, take them out, put them in a vacuum tank, and evacuate the vacuum to 10Pa, maintain for 0.5 hours, and take them out for use; (4) Component dipping: Place the wire frame with components in the wax box. During the wax dipping process, the wax temperature must be kept constant at 90°C. The wax dipping time is 15 minutes. Take out the wire frame with components and drip wax in an oven for 15 minutes. The oven temperature is maintained at 95°C. (5) Inspection: The components are fully wetted and wax-impregnated evenly; (6) Component unloading: Take out the components, wipe them with a clean cloth, and put them into the turnover box; Among them, the deviation of the above temperatures can be within ±2%, and the deviation of each time can be within ±5%.

[0017] Furthermore, the melting point of the paraffin wax used is 80°C.

[0018] Furthermore, the metallized film of the film capacitor is resistant to high temperatures, ranging from 95 to 105°C; excessively high wax temperatures will cause the film to expand, and the wax temperature is controlled at 90°C.

[0019] Furthermore, operators need to wear gloves and long-sleeved and long-trouser work clothes.

[0020] Furthermore, operators should concentrate when working, handle components with care, and ensure that components are fully cooled after operation.

[0021] Furthermore, the temperature of the vacuum tank and oven must be maintained and must not be adjusted at will.

[0022] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A film capacitor element impregnation process, the process comprising the following steps: (1) Component preparation: The components are primed with solder, and a constant temperature soldering iron is used, with a temperature of 450-480 degrees and a soldering point diameter of 6 mm²; the components are placed horizontally in a wire frame and arranged neatly, and then pushed into the work area with a trolley; (2) Dipping preparation: Place the wax dipping tank in an oven, turn on the oven and adjust the heating temperature to 90°C, start the oven and run it until the wax in the wax tank is completely melted and the wax temperature rises to 90°C, and maintain it for 4 hours; (3) Component preheating: Place the components in the wire frame together with the wire frame in a 95°C oven, heat for 3 hours, take them out, put them in a vacuum tank, and evacuate the vacuum to 10Pa, maintain for 0.5 hours, and take them out for use; (4) Component dipping: Place the wire frame with components in the wax box. During the wax dipping process, the wax temperature must be kept constant at 90°C. The wax dipping time is 15 minutes. Take out the wire frame with components and drip wax in an oven for 15 minutes. The oven temperature is maintained at 95°C. (5) Inspection: The components are fully wetted and wax-impregnated evenly; (6) Component unloading: Take out the components, wipe them with a clean cloth, and put them into the turnover box; in, The deviation of the above temperatures can be within ±2%, and the deviation of each time can be within ±5%.