A ceramic capacitor encapsulation process

Abstract

The application provides a ceramic capacitor encapsulation process, which comprises the following steps: S1, encapsulating a 0.8mm-1.0mm insulating paint layer on the surface of a ceramic capacitor; S2, coating a 1.6mm-1.8mm hyperbranched epoxy resin layer on the surface of the capacitor obtained in step S1; and S3, coating a 0.4mm-0.6mm bisphenol A type epoxy resin layer on the surface of the capacitor obtained in step S2. The application adopts three different encapsulation materials for three times of encapsulation, simultaneously optimizes the thickness of each encapsulation layer, fully utilizes the characteristics of the three encapsulation materials, can significantly reduce the residual stress of the encapsulation layer, improves the interfacial bonding force between the encapsulation layer and the ceramic capacitor, reduces the cracking risk, improves the stability and reliability of the ceramic capacitor, and further improves the voltage resistance strength of the ceramic capacitor.

Description

Technical Field

[0001] This invention relates to the field of ceramic capacitors, and in particular to a ceramic capacitor encapsulation process. Background Technology

[0002] Ceramic capacitors are indispensable electronic components in computer communications, home appliances, various switching power supplies, and many electronic instruments, playing a crucial role in coupling, bridging, and bypassing circuits. Ceramic chips exposed to air are prone to moisture absorption. Moisture absorption can lead to unstable withstand voltage performance during storage and use, reducing the capacitor's breakdown strength and, in severe cases, causing dielectric breakdown and rendering it unusable. Furthermore, due to the brittleness of ceramic chips, the substrate is easily subjected to external impacts during transportation, assembly, and use, resulting in cracks or even breakage, causing capacitor failure and directly affecting the safety of the entire device. Therefore, encapsulation is essential for ceramic capacitors. After encapsulation and curing, the resin encapsulation layer adheres firmly and densely to the capacitor surface, providing excellent moisture protection. The quality of the moisture-proof performance of the encapsulation layer directly affects the capacitor's electrical performance and reliability. Meanwhile, for high-voltage ceramic capacitors, a good encapsulation layer can significantly increase the breakdown voltage. This is because the electric field intensity distribution at the electrode edges is severely distorted, and a good encapsulation layer can improve the edge electric field. After encapsulation, the surface distance between the two leads of the capacitor increases significantly, thus greatly improving the breakdown voltage and reliability. However, different encapsulation materials have a very large impact on the withstand voltage. To obtain a ceramic capacitor with high withstand voltage performance, in addition to a qualified ceramic chip, a high-quality and reliable encapsulation layer is also required.

[0003] Ceramic capacitors generally require encapsulation materials with high dielectric constant, high voltage resistance, moisture resistance, and aging resistance. Epoxy resin is a relatively ideal material to meet these requirements because it has high dielectric strength, good moisture resistance, and aging resistance, while also possessing good adhesion and mechanical properties. Therefore, epoxy resin-based materials are currently generally chosen as the encapsulation layer for ceramic capacitors. According to research, the current encapsulation layer for ceramic capacitors is a single-layer epoxy resin-based material. Research focuses primarily on modifying this single-layer material (e.g., adding toughening agents) or optimizing encapsulation process parameters (e.g., drying temperature, curing temperature, single-layer thickness). However, the ability of a single-layer epoxy resin-based encapsulation layer to improve breakdown voltage is limited, while withstand voltage is the most important indicator of ceramic capacitor performance. This makes it difficult for a single-layer epoxy resin-based encapsulation layer to meet the performance requirements of high-voltage capacitors.

[0004] In view of the above, there is an urgent need to provide an encapsulation process for ceramic capacitors that gives them excellent moisture resistance and voltage withstand performance.

[0005] It should be noted that the above description of the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this invention. Summary of the Invention

[0006] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a ceramic capacitor encapsulation process with excellent moisture resistance and high withstand voltage, in order to solve the problems of easy cracking and low breakdown voltage of single-layer epoxy resin encapsulation in the prior art.

[0007] To achieve the above and other related objectives, the present invention provides an encapsulation process for a ceramic capacitor, the encapsulation process comprising: S1: Encapsulate the surface of the ceramic capacitor with a layer of insulating varnish; S2: The surface of the capacitor obtained in step S1 is coated with a layer of hyperbranched epoxy resin. S3: The surface of the capacitor obtained in step S2 is coated with a layer of bisphenol A type epoxy resin.

[0008] Optionally, the thickness of the insulating varnish layer is 0.8mm~1.0mm, the thickness of the hyperbranched epoxy resin layer is 1.6mm~1.8mm, and the thickness of the bisphenol A type epoxy resin layer is 0.4mm~0.6mm.

[0009] Optionally, the specific steps of step S1 are as follows: S11: Clean and dry the ceramic capacitor; S12: Weigh the insulating varnish and thinner at a mass ratio of 1:5~10, mix them evenly, and obtain the insulating varnish impregnation solution; S13: Immerse the dried ceramic capacitor in the insulating varnish impregnation solution, remove it and dry it in an oven, and then encapsulate the surface of the ceramic capacitor with a layer of insulating varnish.

[0010] Optionally, in step S11, the cleaning is performed using ultrasonic cleaning, the drying temperature is 80~100℃, and the drying time is 10~20min.

[0011] Optionally, the insulating varnish is one of amino-based drying insulating varnish or alkyd-based drying insulating varnish, and the diluent is xylene or X-4 amino diluent.

[0012] Optionally, the specific steps of step S2 are as follows: S21: Weigh 45-55 parts of hyperbranched epoxy resin and 25-25 parts of curing agent, mix them evenly to obtain a hyperbranched epoxy resin layer mixed powder. S22: After preheating the capacitor obtained in step S1, place it in the powder tank to dip it in the mixed powder for 3~5 seconds. After melting and solidifying, encapsulate a layer of hyperbranched epoxy resin on the surface of the insulating varnish layer.

[0013] Optionally, the hyperbranched epoxy resin is one of EV2098F, HyPerE10, and HyPerE20; The curing agent is selected from one of 4,4′-diaminodiphenyl sulfone, methyltetrahydrophthalic anhydride, and polyamide amine.

[0014] Optionally, the specific steps of step S3 are as follows: S31: Weigh 50-60 parts of bisphenol A type epoxy resin and 20-30 parts of curing agent, mix them evenly to obtain bisphenol A type epoxy resin layer mixed powder. S32: After preheating the capacitor obtained in step S2, place it in the powder tank to dip it in the mixed powder for 1~2 seconds. After melting and solidifying, encapsulate a layer of bisphenol A type epoxy resin on the surface of the hyperbranched epoxy resin layer.

[0015] Optionally, the bisphenol A type epoxy resin is bisphenol A diglycidyl ether, and the curing agent is selected from one of 3-(2-fluoroethoxy)propylamine, triethylenetetramine, and methyltetrahydrophthalic anhydride.

[0016] Optionally, after step S3, step S4 is further included: curing the capacitor obtained in step S3 for 2-3 hours.

[0017] The present invention also provides a ceramic capacitor, which is obtained by encapsulation using the ceramic capacitor encapsulation process described in any one of the above claims.

[0018] As described above, the encapsulation process of the ceramic capacitor of the present invention has the following beneficial effects: (1) The present invention uses three layers of different encapsulation materials for three encapsulations. At the same time, the thickness of each encapsulation layer is optimized. This can overcome the problem of large shrinkage residual stress caused by the single-layer epoxy resin encapsulation layer, which leads to large gaps between the ceramic capacitor and the encapsulation layer. This improves the interfacial bonding force between the encapsulation layer and the ceramic capacitor, thereby improving the stability and reliability of the ceramic capacitor and further improving the breakdown voltage of the ceramic capacitor.

[0019] (2) The insulating varnish layer is tightly bonded to the ceramic capacitor substrate, providing good interfacial adhesion and preventing air gaps or microcracks from appearing between the ceramic capacitor and the resin. The intermediate layer uses hyperbranched epoxy resin, which has a highly branched structure and extremely low shrinkage rate, forming a soft "buffer layer" that plays a role in stress release. The bisphenol A type epoxy resin has a moderate viscosity and is easy to form a uniform thick film, providing overall mechanical support and moisture barrier. Compared with the insulating varnish + epoxy resin layer structure in the prior art, the three-layer encapsulation layer structure can better play a synergistic role, making the overall encapsulation layer have better stability and voltage resistance. Detailed Implementation

[0020] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0021] When describing the embodiments of the present invention in detail, for ease of explanation, the cross-sectional views showing the device structure will be partially enlarged without adhering to the general scale, and the schematic diagrams are merely examples and should not limit the scope of protection of the present invention.

[0022] For ease of description, spatial relation terms such as “below,” “below,” “less than,” “below,” “above,” and “upper” may be used here to describe the relationship of one structure or feature to other structures or features. It will be understood that these spatial relation terms are intended to include directions other than those depicted in the device in use or operation. Furthermore, when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or there may be one or more layers in between. The phrase “between” as used herein includes both endpoint values.

[0023] In the context of this invention, the described structure of the first feature "above" the second feature may include embodiments in which the first and second features are formed in direct contact, or embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0024] To achieve the above and other related objectives, the present invention provides an encapsulation process for a ceramic capacitor, the encapsulation process comprising: S1: Encapsulate the surface of the ceramic capacitor with a layer of insulating varnish; S2: The surface of the capacitor obtained in step S1 is coated with a layer of hyperbranched epoxy resin. S3: The surface of the capacitor obtained in step S2 is coated with a layer of bisphenol A type epoxy resin.

[0025] Optionally, the thickness of the insulating varnish layer is 0.8mm~1.0mm, the thickness of the hyperbranched epoxy resin layer is 1.6mm~1.8mm, and the thickness of the bisphenol A type epoxy resin layer is 0.4mm~0.6mm.

[0026] Optionally, the specific steps of step S1 are as follows: S11: Clean and dry the ceramic capacitor; S12: Weigh the insulating varnish and thinner at a mass ratio of 1:5~10, mix them evenly, and obtain the insulating varnish impregnation solution; S13: Immerse the dried ceramic capacitor in the insulating varnish impregnation solution, remove it and dry it in an oven, and then encapsulate the surface of the ceramic capacitor with a layer of insulating varnish.

[0027] Optionally, in step S11, the cleaning is performed using ultrasonic cleaning, the drying temperature is 80~100℃, and the drying time is 10~20min.

[0028] Optionally, the insulating varnish is one of amino-based drying insulating varnish or alkyd-based drying insulating varnish, and the diluent is xylene or X-4 amino diluent.

[0029] Optionally, the specific steps of step S2 are as follows: S21: Weigh 45-55 parts of hyperbranched epoxy resin and 25-25 parts of curing agent, mix them evenly to obtain a hyperbranched epoxy resin layer mixed powder. S22: After preheating the capacitor obtained in step S1, place it in the powder tank to dip it in the mixed powder for 3~5 seconds. After melting and solidifying, encapsulate a layer of hyperbranched epoxy resin on the surface of the insulating varnish layer.

[0030] Optionally, the hyperbranched epoxy resin is one of EV2098F, HyPerE10, and HyPerE20; The curing agent is selected from one of 4,4′-diaminodiphenyl sulfone, methyltetrahydrophthalic anhydride, and polyamide amine.

[0031] Optionally, the specific steps of step S3 are as follows: S31: Weigh 50-60 parts of bisphenol A type epoxy resin and 20-30 parts of curing agent, mix them evenly to obtain bisphenol A type epoxy resin layer mixed powder. S32: After preheating the capacitor obtained in step S2, place it in the powder tank to dip it in the mixed powder for 1~2 seconds. After melting and solidifying, encapsulate a layer of bisphenol A type epoxy resin on the surface of the hyperbranched epoxy resin layer.

[0032] Optionally, the bisphenol A type epoxy resin is bisphenol A diglycidyl ether, and the curing agent is selected from one of 3-(2-fluoroethoxy)propylamine, triethylenetetramine, and methyltetrahydrophthalic anhydride.

[0033] Optionally, after step S3, step S4 is further included: curing the capacitor obtained in step S3 for 2-3 hours.

[0034] The present invention also provides a ceramic capacitor, which is obtained by encapsulation using the ceramic capacitor encapsulation process described in any one of the above claims.

[0035] This invention employs three layers of different encapsulating materials for triple encapsulation, while optimizing the thickness of each encapsulation layer. This overcomes the problem of large gaps between the ceramic capacitor and the encapsulation layer caused by the significant residual shrinkage stress of a single-layer epoxy resin encapsulation layer. It improves the interfacial bonding between the encapsulation layer and the ceramic capacitor, thereby enhancing the stability and reliability of the ceramic capacitor and further increasing its breakdown voltage. The insulating varnish layer adheres tightly to the ceramic capacitor substrate, providing excellent interfacial adhesion and preventing air gaps or microcracks between the ceramic capacitor and the resin. The intermediate layer uses hyperbranched epoxy resin, which has a highly branched structure and extremely low shrinkage, forming a soft "buffer layer" that releases stress. The bisphenol A epoxy resin has moderate viscosity and easily forms a uniform thick film, providing overall mechanical support and a moisture barrier.

[0036] Example 1 This embodiment provides an encapsulation process for a ceramic capacitor, the specific encapsulation process being as follows: S1: Encapsulating insulating varnish layer S11: Place the barium titanate-based VY5U-1000-5kV ceramic capacitor in an ultrasonic cleaner for 15 minutes, and then place it in a drying oven to dry at 80℃ for 20 minutes. S12: Weigh out amino drying insulating varnish and X-4 amino thinner at a mass ratio of 1:8, mix them evenly, and obtain the insulating varnish impregnation solution. S13: Immerse the dried ceramic capacitor in the insulating varnish impregnation solution, remove it and dry it in an oven, and then encapsulate the surface of the ceramic capacitor with a 0.8mm insulating varnish layer.

[0037] S2: Encapsulating hyperbranched epoxy resin layer S21: Weigh 45 parts of hyperbranched epoxy resin HyPerE10 and 25 parts of curing agent methyltetrahydrophthalic anhydride, mix them evenly to obtain hyperbranched epoxy resin layer mixed powder. S22: After preheating the capacitor obtained in step S1, place it in the powder tank to dip it in the mixed powder for 3 seconds. After melting and solidifying, encapsulate the surface of the insulating varnish layer with a 1.6mm hyperbranched epoxy resin layer.

[0038] S3: Encapsulating bisphenol A type epoxy resin layer S31: Weigh 50 parts of bisphenol A diglycidyl ether and 20 parts of curing agent triethylenetetramine, mix them evenly to obtain bisphenol A type epoxy resin layer mixed powder. S32: After preheating the capacitor obtained in step S2, place it in the powder tank to dip into the mixed powder for 1 second. After melting and solidifying, encapsulate a 0.4 mm bisphenol A type epoxy resin layer on the surface of the hyperbranched epoxy resin layer.

[0039] S4: Cure the obtained ceramic capacitor for 2 hours to obtain a fully encapsulated ceramic capacitor.

[0040] Example 2 This embodiment provides an encapsulation process for a ceramic capacitor, the specific preparation method including: S1: Encapsulating insulating varnish layer S11: Place the barium titanate-based VY5U-1000-5kV ceramic capacitor in an ultrasonic cleaner for 15 minutes, and then place it in a drying oven to dry at 80℃ for 20 minutes. S12: Weigh out amino drying insulating varnish and X-4 amino thinner at a mass ratio of 1:8, mix them evenly, and obtain the insulating varnish impregnation solution. S13: Immerse the dried ceramic capacitor in the insulating varnish impregnation solution, remove it and dry it in an oven, and then encapsulate the surface of the ceramic capacitor with a 1.0 mm insulating varnish layer.

[0041] S2: Encapsulating hyperbranched epoxy resin layer S21: Weigh 45 parts of hyperbranched epoxy resin HyPerE10 and 25 parts of curing agent methyltetrahydrophthalic anhydride, mix them evenly to obtain hyperbranched epoxy resin layer mixed powder. S22: After preheating the capacitor obtained in step S1, place it in the powder tank to dip it in the mixed powder for 3 seconds. After melting and solidifying, encapsulate the surface of the insulating varnish layer with a 1.8mm hyperbranched epoxy resin layer.

[0042] S3: Encapsulating bisphenol A type epoxy resin layer S31: Weigh 50 parts of bisphenol A diglycidyl ether and 20 parts of curing agent triethylenetetramine, mix them evenly to obtain bisphenol A type epoxy resin layer mixed powder. S32: After preheating the capacitor obtained in step S2, place it in the powder tank to dip it in the mixed powder for 1 second. After melting and solidifying, encapsulate the surface of the hyperbranched epoxy resin layer with a 0.6 mm bisphenol A type epoxy resin layer.

[0043] S4: Cure the obtained ceramic capacitor for 2 hours to obtain a fully encapsulated ceramic capacitor.

[0044] Comparative Example 1 This embodiment provides an encapsulation process for a ceramic capacitor, the specific preparation method including: S1: Encapsulating insulating varnish layer S11: Place the barium titanate-based VY5U-1000-5kV ceramic capacitor in an ultrasonic cleaner for 15 minutes, and then place it in a drying oven to dry at 80℃ for 20 minutes. S12: Weigh out amino drying insulating varnish and X-4 amino thinner at a mass ratio of 1:8, mix them evenly, and obtain the insulating varnish impregnation solution. S13: Immerse the dried ceramic capacitor in the insulating varnish impregnation solution, remove it and dry it in an oven, and then encapsulate the surface of the ceramic capacitor with a 0.6mm insulating varnish layer.

[0045] S2: Encapsulating hyperbranched epoxy resin layer S21: Weigh 45 parts of hyperbranched epoxy resin HyPerE10 and 25 parts of curing agent methyltetrahydrophthalic anhydride, mix them evenly to obtain hyperbranched epoxy resin layer mixed powder. S22: After preheating the capacitor obtained in step S1, place it in the powder tank to dip it in the mixed powder for 3 seconds. After melting and solidifying, encapsulate the surface of the insulating varnish layer with a 1.4mm hyperbranched epoxy resin layer.

[0046] S3: Encapsulating bisphenol A type epoxy resin layer S31: Weigh 50 parts of bisphenol A diglycidyl ether and 20 parts of curing agent triethylenetetramine, mix them evenly to obtain bisphenol A type epoxy resin layer mixed powder. S32: After preheating the capacitor obtained in step S2, place it in the powder tank to dip into the mixed powder for 1 second. After melting and solidifying, encapsulate the surface of the hyperbranched epoxy resin layer with a 0.2 mm bisphenol A type epoxy resin layer.

[0047] S4: Cure the obtained ceramic capacitor for 2 hours to obtain a fully encapsulated ceramic capacitor.

[0048] Comparative Example 2 This embodiment provides an encapsulation process for a ceramic capacitor, the specific preparation method including: S1: Encapsulating insulating varnish layer S11: Place the barium titanate-based VY5U-1000-5kV ceramic capacitor in an ultrasonic cleaner for 15 minutes, and then place it in a drying oven to dry at 80℃ for 20 minutes. S12: Weigh out amino drying insulating varnish and X-4 amino thinner at a mass ratio of 1:8, mix them evenly, and obtain the insulating varnish impregnation solution. S13: Immerse the dried ceramic capacitor in the insulating varnish impregnation solution, remove it and dry it in an oven, and then encapsulate the surface of the ceramic capacitor with a 1.2mm insulating varnish layer.

[0049] S2: Encapsulating hyperbranched epoxy resin layer S21: Weigh 45 parts of hyperbranched epoxy resin HyPerE10 and 25 parts of curing agent methyltetrahydrophthalic anhydride, mix them evenly to obtain hyperbranched epoxy resin layer mixed powder. S22: After preheating the capacitor obtained in step S1, place it in the powder tank to dip it in the mixed powder for 4 seconds. After melting and solidifying, encapsulate the surface of the insulating varnish layer with a 2.0 mm hyperbranched epoxy resin layer.

[0050] S3: Encapsulating bisphenol A type epoxy resin layer S31: Weigh 50 parts of bisphenol A diglycidyl ether and 20 parts of curing agent triethylenetetramine, mix them evenly to obtain bisphenol A type epoxy resin layer mixed powder. S32: After preheating the capacitor obtained in step S2, place it in the powder tank to dip it in the mixed powder for 2 seconds. After melting and solidifying, encapsulate the surface of the hyperbranched epoxy resin layer with a 0.8mm bisphenol A type epoxy resin layer.

[0051] S4: Cure the obtained ceramic capacitor for 2 hours to obtain a fully encapsulated ceramic capacitor.

[0052] Comparative Example 3 This embodiment provides an encapsulation process for a ceramic capacitor, the specific preparation method including: S1: Encapsulating insulating varnish layer S11: Place the barium titanate-based VY5U-1000-5kV ceramic capacitor in an ultrasonic cleaner for 15 minutes, and then place it in a drying oven to dry at 80℃ for 20 minutes. S12: Weigh out amino drying insulating varnish and X-4 amino thinner at a mass ratio of 1:8, mix them evenly, and obtain the insulating varnish impregnation solution. S13: Immerse the dried ceramic capacitor in the insulating varnish impregnation solution, remove it and dry it in an oven, and then encapsulate the surface of the ceramic capacitor with a 0.8mm insulating varnish layer.

[0053] S2: Encapsulating hyperbranched epoxy resin layer S21: Weigh 45 parts of hyperbranched epoxy resin HyPerE10 and 25 parts of curing agent methyltetrahydrophthalic anhydride, mix them evenly to obtain hyperbranched epoxy resin layer mixed powder. S22: After preheating the capacitor obtained in step S1, place it in the powder tank to dip it in the mixed powder for 5 seconds. After melting and solidifying, encapsulate a 2.0 mm hyperbranched epoxy resin layer on the surface of the insulating varnish layer.

[0054] S4: Cure the obtained ceramic capacitor for 2 hours to obtain a fully encapsulated ceramic capacitor.

[0055] Comparative Example 4 This embodiment provides an encapsulation process for a ceramic capacitor, the specific encapsulation process being as follows: S1: Encapsulating insulating varnish layer S11: Place the barium titanate-based VY5U-1000-5kV ceramic capacitor in an ultrasonic cleaner for 15 minutes, and then place it in a drying oven to dry at 80℃ for 20 minutes. S12: Weigh out amino drying insulating varnish and X-4 amino thinner at a mass ratio of 1:8, mix them evenly, and obtain the insulating varnish impregnation solution. S13: Immerse the dried ceramic capacitor in the insulating varnish impregnation solution, remove it and dry it in an oven, and then encapsulate the surface of the ceramic capacitor with a 0.8mm insulating varnish layer.

[0056] S3: Encapsulated bisphenol A type epoxy resin layer S31: Weigh 50 parts of bisphenol A diglycidyl ether and 20 parts of curing agent triethylenetetramine, mix them evenly to obtain bisphenol A type epoxy resin layer mixed powder. S32: After preheating the capacitor obtained in step S2, place it in the powder tank to dip it in the mixed powder for 5 seconds. After melting and solidifying, encapsulate a 2.0 mm bisphenol A type epoxy resin layer on the surface of the hyperbranched epoxy resin layer.

[0057] S4: Cure the obtained ceramic capacitor for 2 hours to obtain a fully encapsulated ceramic capacitor.

[0058] The ceramic capacitors prepared in Examples 1-2 and Comparative Examples 1-3 were subjected to withstand voltage tests. The specific test results are detailed in Table 1.

[0059] Table 1. Withstand Voltage of Ceramic Capacitors ; As can be seen from Examples 1, 3, and 4, the present invention employs three different encapsulation materials for a three-layer encapsulation process. Compared to a single-layer encapsulation process using a single resin encapsulation material, the resulting ceramic capacitor exhibits a significant improvement in withstand voltage performance. Furthermore, as shown in Examples 1-4, the thickness of each encapsulation layer in the three-layer encapsulation process also has a substantial impact on the withstand voltage performance of the ceramic capacitor. Only when both the encapsulation material and the encapsulation thickness are suitable can excellent withstand voltage be achieved.

[0060] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. An encapsulation process for a ceramic capacitor, characterized in that, The encapsulation process of the ceramic capacitor includes: S1: Encapsulate the surface of the ceramic capacitor with a layer of insulating varnish; S2: The surface of the capacitor obtained in step S1 is coated with a layer of hyperbranched epoxy resin. S3: The surface of the capacitor obtained in step S2 is coated with a layer of bisphenol A type epoxy resin.

2. The encapsulation process for the ceramic capacitor according to claim 1, characterized in that, The thickness of the insulating varnish layer is 0.8mm~1.0mm, the thickness of the hyperbranched epoxy resin layer is 1.6mm~1.8mm, and the thickness of the bisphenol A type epoxy resin layer is 0.4mm~0.6mm.

3. The encapsulation process for the ceramic capacitor according to claim 1 or 2, characterized in that, The specific steps of step S1 are as follows: S11: Clean and dry the ceramic capacitor; S12: Weigh the insulating varnish and thinner at a mass ratio of 1:5~10, mix them evenly, and obtain the insulating varnish impregnation solution; S13: Immerse the dried ceramic capacitor in the insulating varnish impregnation solution, remove it and dry it in an oven, and then encapsulate the surface of the ceramic capacitor with a layer of insulating varnish.

4. The encapsulation process for the ceramic capacitor according to claim 3, characterized in that, In step S11, the cleaning is performed using ultrasonic cleaning, the drying temperature is 80~100℃, and the drying time is 10~20min.

5. The encapsulation process for the ceramic capacitor according to claim 3, characterized in that, The insulating varnish is one of amino-based drying insulating varnish or alkyd-based drying insulating varnish, and the diluent is xylene or X-4 amino diluent.

6. The encapsulation process for the ceramic capacitor according to claim 1 or 2, characterized in that, The specific steps of step S2 are as follows: S21: Weigh 45-55 parts of hyperbranched epoxy resin and 25-25 parts of curing agent, mix them evenly to obtain a hyperbranched epoxy resin layer mixed powder. S22: After preheating the capacitor obtained in step S1, place it in the powder tank to dip it in the mixed powder for 3~5 seconds. After melting and solidifying, encapsulate a layer of hyperbranched epoxy resin on the surface of the insulating varnish layer.

7. The encapsulation process for the ceramic capacitor according to claim 6, characterized in that, The hyperbranched epoxy resin is one of EV2098F, HyPerE10, and HyPerE20; The curing agent is selected from one of 4,4′-diaminodiphenyl sulfone, methyltetrahydrophthalic anhydride, and polyamide amine.

8. The encapsulation process for the ceramic capacitor according to claim 1 or 2, characterized in that, The specific steps of step S3 are as follows: S31: Weigh 50-60 parts of bisphenol A type epoxy resin and 20-30 parts of curing agent, mix them evenly to obtain bisphenol A type epoxy resin layer mixed powder. S32: After preheating the capacitor obtained in step S2, place it in the powder tank to dip it in the mixed powder for 1~2 seconds. After melting and solidifying, encapsulate a layer of bisphenol A type epoxy resin on the surface of the hyperbranched epoxy resin layer.

9. The encapsulation process for the ceramic capacitor according to claim 8, wherein the bisphenol A type epoxy resin is bisphenol A diglycidyl ether, and the curing agent is selected from one of 3-(2-fluoroethoxy)propylamine, triethylenetetramine, and methyltetrahydrophthalic anhydride.

10. The encapsulation process for the ceramic capacitor according to claim 1 or 2, further comprising, after step S3, S4: Cure the capacitor obtained in step S3 for 2~3 hours.