Solid-state capacitor and preparation method thereof

Abstract

The invention discloses a solid-state capacitor and a preparation method thereof. The method comprises the following steps: S1, winding a core wrap; s2, formation treatment; s3, drying the core package; s4, core package impregnation treatment: immersing the core package dried in the step S3 into impregnation liquid; s5, core cladding polymerization; s6, assembling and girdling; s7, aging; wherein the impregnation liquid used in the step S4 is composed of a conductive polymer poly (3, 4-ethylenedioxythiophene)-polystyrolsulfon acid, purified water and an additive; wherein the additive is composed of methanol, ethanol, isopropanol and colloidal silicon. According to the method provided by the invention, the production efficiency is improved, the production cost is reduced and better economic benefits are achieved under the condition that the process yield, the characteristics and the service life of the produced solid-state capacitor are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolytic capacitors, and more specifically, to a solid capacitor and a preparation method thereof. Background Art

[0002] Solid capacitors, also known as solid aluminum electrolytic capacitors, are capacitors that use conductive polymer materials as dielectric materials. Compared with traditional liquid aluminum electrolytic capacitors, the main difference between solid capacitors is the difference in their dielectric materials. The dielectric material of liquid aluminum electrolytic capacitors is electrolyte, while the dielectric material of solid capacitors is conductive polymer materials. Compared with ordinary liquid aluminum electrolytic capacitors, solid capacitors have the characteristics of high reliability, long service life, high frequency, low impedance, and resistance to extremely large ripple current. They are also conducive to the integration and miniaturization of electronic products and can overcome the disadvantage of liquid aluminum electrolytic capacitors that are prone to leakage.

[0003] The production of solid-state capacitors usually requires multiple impregnation and drying, and the preparation process is inefficient. In addition, the performance of the produced solid-state capacitors changes greatly after reflow soldering. For example, Chinese patent application (CN104637687A) discloses a method for manufacturing a high-voltage solid electrolyte aluminum electrolytic capacitor, including: (1) welding the core package to an iron bar, applying voltage for chemical formation, and cleaning and drying after chemical formation; (2) immersing the dried core package in dispersion A for 1 to 30 minutes; (3) removing the core package from dispersion A, evacuating the core package and immersing the core package in dispersion A again for 1 to 10 minutes; (4) retaining the core package in dispersion A. , breaking the vacuum and then pressurizing, the impregnation time is 1 to 10 minutes; (5) keeping the core package in dispersion A, venting to normal pressure, the impregnation time is 1 to 10 minutes; (6) taking out the core package, drying the core package at 65 to 100°C for 20 to 60 minutes, and then drying the core package at 135 to 165°C for 20 to 60 minutes; (7) steps (3) to (6) are repeated at least once; (8) sealing the shell and aging treatment; wherein the dispersion A is a dispersion containing a conductive polymer. The impregnation and drying steps of the patented method are complicated, time-consuming, and have a high production cost.

[0004] Therefore, there is an urgent need to propose a low-cost, efficient, and high-performance solid-state capacitor preparation method. Summary of the invention

[0005] Based on this, it is necessary to provide a solid-state capacitor with stable performance and a preparation method thereof to address the above technical problems.

[0006] In order to solve the above technical problems, the first aspect of the present invention proposes a method for preparing a solid capacitor, which adopts the following technical solution:

[0007] A method for preparing a solid capacitor comprises the following steps:

[0008] S1, core wrapping roll;

[0009] S2, chemical treatment;

[0010] S3, core package drying treatment;

[0011] S4, the core package is impregnated, and the core package after the drying process in step S3 is immersed in the impregnation liquid;

[0012] S5, core package polymerization;

[0013] S6, assemble the waist;

[0014] S7, aging;

[0015] The impregnation solution used in step S4 is composed of a conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, pure water and additives;

[0016] Wherein, the additive consists of methanol, ethanol, isopropanol and colloidal silicon.

[0017] Furthermore, the impregnation solution is composed of the following components by mass percentage: 2.7% to 3.3% of conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 71.4% to 72.6% of pure water, and 24.7% to 25.3% of additives.

[0018] Furthermore, the mass ratio of methanol, ethanol, isopropanol and colloidal silicon in the additive is 1-2.6:10-21:6-13:8-16.6.

[0019] Furthermore, the impregnation treatment is performed under a vacuum pressure of -90Kpa to -98Kpa for 280 to 320 seconds.

[0020] Furthermore, the core package polymerization of S5 is to heat the impregnated core package at 145 to 155° C. for 25 to 35 minutes.

[0021] Furthermore, the impregnation treatment in step S4 and the core package polymerization in step S5 are repeated 1 to 2 times.

[0022] Furthermore, the material of the electrolytic paper is a mixed fiber of plant fiber and synthetic fiber.

[0023] Furthermore, the particle size of the conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is less than 300 um, and the particle size of the colloidal silica is less than 100 um.

[0024] A second aspect of the present invention provides a solid-state capacitor prepared by any of the above methods.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The solid capacitor preparation method proposed in the present invention increases the vacuum degree of the impregnation treatment so that the impregnation liquid can quickly enter the core package, reducing the impregnation time, while increasing the polymerization temperature, shortening the polymerization time of the core package, and accelerating the discharge of water in the core package, so that the polymerization process can be completed in the shortest time. Combined with the low conductivity formula and low viscosity conductive polymer solution selected by the present invention, the impregnation and dispersion effect is good, and the solution can quickly penetrate into the core package. The method proposed in the present invention improves production efficiency and reduces production costs while ensuring the process yield, characteristics and life of the solid capacitor produced, thereby achieving better economic benefits. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0028] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application is clearly and completely described below.

[0029] Example 1

[0030] This embodiment provides a method for preparing a solid-state capacitor, which includes the following steps:

[0031] S1. Core package winding: Electrolytic paper is inserted between the anode foil and the cathode foil and wound into a core package. The anode foil is anode foil with high pressure resistance and low specific volume. The electrolytic paper is low-density mixed fiber electrolytic paper, which is composed of plant fiber and synthetic fiber.

[0032] S2, chemical treatment;

[0033] S3, core package drying treatment;

[0034] S4, core package impregnation treatment: immersing the core package after the drying treatment in step S3 into the impregnation liquid for impregnation treatment to obtain an impregnated core package; wherein the impregnation treatment is performed under a vacuum pressure of -90Kpa for 300 seconds to allow the impregnation liquid to fully impregnate the electrolytic paper;

[0035] S5, core package polymerization: heating the impregnated core package for polymerization at 150° C. for 30 minutes;

[0036] Steps S4 and S5 can be repeated 1 to 2 times, and in this embodiment, they are repeated once;

[0037] S6, assemble the waist;

[0038] S7, aging;

[0039] The impregnation solution used in step S4 is composed of the following components by mass percentage: 3% conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and 97% pure water.

[0040] Wherein, the particle size of the conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is 200 um.

[0041] The electrical properties of the solid capacitor prepared in Example 1 were tested, and the results are shown in Table 1 and Table 2:

[0042] Table 1: Test results after second dispersion immersion in this example

[0043]

[0044] Table 2: Comparison of results before and after reflow soldering in this embodiment

[0045]

[0046] Example 2

[0047] This embodiment provides a method for preparing a solid-state capacitor, which differs from Embodiment 1 in that:

[0048] The impregnation liquid used in step S4 is composed of the following components by mass percentage: dispersion formula poly (3%, 5-ethylenedioxythiophene)-polystyrene sulfonate, 72% water, 25% additive; wherein the additive is methanol.

[0049] The electrical properties of the solid capacitor prepared in Example 2 were tested, and the results are shown in Table 3 and Table 4:

[0050] Table 3: Test results after second dispersion immersion in this example

[0051]

[0052] Table 4: Comparison of results before and after reflow soldering in this embodiment

[0053]

[0054] Example 3

[0055] This embodiment provides a method for preparing a solid-state capacitor, which differs from Embodiment 2 in that:

[0056] The additive of the impregnation solution used in step S4 is composed of methanol and ethanol in a mass ratio of 1:10.

[0057] The electrical properties of the solid capacitor prepared in Example 3 were tested, and the results are shown in Table 5 and Table 6:

[0058] Table 5: Test results after second dispersion immersion in this example

[0059]

[0060] Table 6: Comparison of results before and after reflow soldering in this embodiment

[0061]

[0062] Example 4

[0063] This embodiment provides a method for preparing a solid-state capacitor, which differs from Embodiment 3 in that:

[0064] The additive of the impregnation solution used in step S4 is composed of methanol, ethanol and isopropanol in a mass ratio of 1:10:6.

[0065] The electrical properties of the solid capacitor prepared in Example 4 were tested, and the results are shown in Table 7 and Table 8:

[0066] Table 7: Test results after second dispersion immersion in this example

[0067]

[0068] Table 8: Comparison of results before and after reflow soldering in this embodiment

[0069]

[0070] Example 5

[0071] This embodiment provides a method for preparing a solid capacitor, which differs from Embodiment 4 in that:

[0072] The additive of the impregnation liquid used in step S4 is composed of methanol, ethanol, isopropanol and colloidal silicon in a mass ratio of 1:10:6:8; the particle size of the colloidal silicon is 80 um.

[0073] The electrical properties of the solid capacitor prepared in Example 5 were tested, and the results are shown in Tables 9 and 10:

[0074] Table 9: Test results after second dispersion immersion in this example

[0075]

[0076] Table 10: Comparison of results of this embodiment before and after reflow soldering

[0077]

[0078] Example 6

[0079] This embodiment provides a method for preparing a solid-state capacitor, which differs from Embodiment 5 in that:

[0080] S4, core package impregnation treatment: immersing the core package after the drying treatment in step S3 into the impregnation liquid for impregnation treatment to obtain an impregnated core package; wherein the impregnation treatment is performed under a vacuum pressure of -95Kpa for 320 seconds, so that the impregnation liquid is fully impregnated into the electrolytic paper;

[0081] S5, core package polymerization: heating the impregnated core package for polymerization at 155° C. for 25 minutes;

[0082] Steps S4 and S5 are repeated once;

[0083] The impregnation solution used in step S4 is composed of the following components by mass percentage: 3.3% conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 71.4% pure water, and 25.3% additives.

[0084] The additive is composed of methanol, ethanol, isopropanol and colloidal silicon in a mass ratio of 2.6:21:11:15.4.

[0085] The particle size of the conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is 250 um, and the particle size of the colloidal silica is 50 um.

[0086] The electrical properties of the solid capacitor prepared in Example 6 were tested, and the results are shown in Tables 11 and 12:

[0087] Table 11: Test results of this embodiment after second immersion in dispersion liquid

[0088]

[0089] Table 12: Comparison of results of this embodiment before and after reflow soldering

[0090]

[0091] Example 7

[0092] This embodiment provides a method for preparing a solid-state capacitor, which differs from Embodiment 5 in that:

[0093] S4, core package impregnation treatment: immersing the core package after the drying treatment in step S3 into the impregnation liquid for impregnation treatment to obtain an impregnated core package; wherein the impregnation treatment is performed under a vacuum pressure of -98Kpa for 280 seconds to allow the impregnation liquid to fully impregnate the electrolytic paper;

[0094] S5, core package polymerization: heating the impregnated core package for polymerization at 145° C. for 35 minutes;

[0095] Steps S4 and S5 are repeated once;

[0096] The impregnation solution used in step S4 is composed of the following components by mass percentage: 2.7% conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 72.6% pure water, and 24.7% additives.

[0097] The additive is composed of methanol, ethanol, isopropanol and colloidal silicon in a mass ratio of 1.4:19:13:16.6.

[0098] Wherein, the particle size of the conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is 100 um, and the particle size of the colloidal silicon is 30 um.

[0099] The electrical properties of the solid capacitor prepared in Example 7 were tested, and the results are shown in Table 13 and Table 14:

[0100] Table 13: Test results of this example after second immersion in dispersion liquid

[0101]

[0102] Table 14: Comparison of results of this embodiment before and after reflow soldering

[0103]

[0104] From the test results, it can be seen that in Examples 5 to 7, due to the improvement of the additive formula in the impregnation liquid, the capacitance performance can still be maintained relatively stable after reflow soldering, and the DF value, ESR value and LC value do not change much before and after reflow soldering. The present invention uses an impregnation liquid formula with low conductivity, which can ensure that the parameter change rate of the solid-state capacitor remains stable after high temperature.

[0105] Comparative Example 1

[0106] This comparative example provides a method for preparing a solid capacitor, which differs from Example 1 in that:

[0107] In step S4, the impregnation treatment is performed under a vacuum pressure of -80 KPa for 700 seconds;

[0108] S5, core package polymerization: heating the impregnated core package for polymerization, the polymerization steps are polymerization at a temperature of 105° C. for 30 minutes, then polymerization at 150° C. for 30 minutes, and finally polymerization at 170° C. for 35 minutes;

[0109] Steps S4 and S5 are repeated once;

[0110] The impregnation solution used in step S4 is composed of the following components by mass percentage: 3.2% conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid and 96.8% pure water.

[0111] Wherein, the particle size of the conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is 200 um.

[0112] The electrical properties of the solid capacitor prepared in Comparative Example 1 were tested, and the results are shown in Tables 15 and 16:

[0113] Table 15: Test results of this comparative example after second dispersion immersion

[0114]

[0115] Table 16: Comparison of the results of this comparative example before and after reflow soldering

[0116]

[0117]

[0118] Comparative Example 2

[0119] This comparative example provides a method for preparing a solid capacitor, which differs from comparative example 1 only in that the impregnation solution used in step S4 is composed of the following components by mass percentage: 3.2% (3,5-ethylenedioxythiophene)-polystyrene sulfonate, 71.6% water, and 25.2% additive; wherein the additive is methanol.

[0120] The electrical properties of the solid capacitor prepared in Comparative Example 2 were tested, and the results are shown in Tables 17 and 18:

[0121] Table 17: Test results of this comparative example after immersion in the second dispersion liquid

[0122]

[0123] Table 18: Comparison of the results of this comparative example before and after reflow soldering

[0124]

[0125]

[0126] Comparative Example 3

[0127] This comparative example provides a method for preparing a solid capacitor, which differs from comparative example 2 only in that the additive of the impregnation solution used in step S4 consists of methanol and ethanol in a mass ratio of 1:10.

[0128] The electrical properties of the solid capacitor prepared in Comparative Example 3 were tested, and the results are shown in Tables 19 and 20:

[0129] Table 19: Test results of this comparative example after immersion in the second dispersion liquid

[0130]

[0131] Table 20: Comparison of the results of this comparative example before and after reflow soldering

[0132]

[0133] Comparative Example 4

[0134] This comparative example provides a method for preparing a solid-state capacitor, which differs from comparative example 4 only in that:

[0135] The additive of the impregnation solution used in step S4 is composed of methanol, ethanol and isopropanol in a mass ratio of 1:10:6.

[0136] The electrical properties of the solid capacitor prepared in Comparative Example 4 were tested, and the results are shown in Tables 21 and 22:

[0137] Table 21: Test results of this comparative example after immersion in the second dispersion liquid

[0138]

[0139] Table 22: Comparison of the results of this comparative example before and after reflow soldering

[0140]

[0141] Comparative Example 5

[0142] This comparative example provides a method for preparing a solid capacitor, which differs from comparative example 4 only in that:

[0143] The additive of the impregnation liquid used in step S4 is composed of methanol, ethanol, isopropanol and colloidal silicon in a mass ratio of 1:10:6:8; the particle size of the colloidal silicon is 80 um.

[0144] The electrical properties of the solid capacitor prepared in Comparative Example 5 were tested, and the results are shown in Table 23 and Table 24:

[0145] Table 23: Test results of this comparative example after immersion in the second dispersion

[0146]

[0147] Table 24: Comparison of the results of this comparative example before and after reflow soldering

[0148]

[0149] Comparative Example 6

[0150] This comparative example provides a method for preparing a solid-state capacitor, which differs from comparative example 5 only in that:

[0151] In the core impregnation process of step S4, the impregnation treatment is performed under a vacuum pressure of -90 KPa for 300 seconds.

[0152] The electrical properties of the solid capacitor prepared in Comparative Example 6 were tested, and the results are shown in Tables 25 and 26:

[0153] Table 25: Test results of this comparative example after immersion in the second dispersion

[0154]

[0155] Table 26: Comparison of the results of this comparative example before and after reflow soldering

[0156]

[0157] Comparative Example 7

[0158] This comparative example provides a method for preparing a solid-state capacitor, which differs from comparative example 6 only in that:

[0159] In step S5, the core package polymerization is performed by heating at 150° C. for 30 minutes.

[0160] The electrical properties of the solid capacitor prepared in Comparative Example 7 were tested, and the results are shown in Tables 27 and 28:

[0161] Table 27: Test results of this comparative example after immersion in the second dispersion

[0162]

[0163] Table 28: Comparison of the results of this comparative example before and after reflow soldering

[0164]

[0165] From the test results, it can be seen that the solid capacitor performance test results of Comparative Examples 5 to 6 are slightly worse than those of Comparative Example 7. Although the impregnation liquid formulas of Comparative Examples 5 to 7 are the same, Comparative Example 7 simplifies the impregnation process while ensuring the performance of the solid capacitor. By increasing the vacuum degree and polymerization temperature during impregnation, the processing time of the impregnation polymerization process is shortened, thereby greatly saving production costs.

[0166] Obviously, the embodiments described above are only part of the embodiments of the present application, not all of the embodiments, but do not limit the patent scope of the present application. The present application can be implemented in many different forms.

[0167] On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned specific embodiments, or to perform equivalent replacements on some of the technical features. Any equivalent structure made using the contents of the present application specification, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present application.

Claims

1. A method for preparing a solid capacitor, characterized in that: The following steps are involved: S1, core wrapping roll; S2, chemical treatment; S3, core package drying treatment; S4, the core package is impregnated, and the core package after the drying process in step S3 is immersed in the impregnation liquid; S5, core package polymerization; S6, assemble the waist; S7, aging; The impregnation solution used in step S4 is composed of a conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, pure water and additives; Wherein, the additive consists of methanol, ethanol, isopropanol and colloidal silicon.

2. The method for preparing a solid capacitor according to claim 1, characterized in that: The impregnation liquid is composed of the following components by mass percentage: 2.7% to 3.3% of conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid, 71.4% to 72.6% of pure water, and 24.7% to 25.3% of additives.

3. The method for preparing a solid capacitor according to claim 2, characterized in that: The mass ratio of methanol, ethanol, isopropanol and colloidal silicon in the additive is 1-2.6:10-21:6-13:8-16.

6.

4. The method for preparing a solid capacitor according to claim 1, characterized in that: The impregnation treatment is performed under a vacuum pressure of -90Kpa to -98Kpa for 280 to 320 seconds.

5. The method for preparing a solid capacitor according to claim 4, characterized in that: The core package polymerization of S5 is to heat the impregnated core package at 145 to 155° C. for 25 to 35 minutes.

6. The method for preparing a solid capacitor according to claim 5, characterized in that: The impregnation treatment of step S4 and the core package polymerization of step S5 are repeated 1 to 2 times.

7. The method for preparing a solid capacitor according to claim 1, characterized in that: The material of the electrolytic paper is mixed fiber of plant fiber and synthetic fiber.

8. The method for preparing a solid capacitor according to claim 1, characterized in that: The particle size of the conductive polymer poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid is less than 300 um, and the particle size of the colloidal silicon is less than 100 um.

9. A solid capacitor, characterized in that: Prepared by any one of the methods of claims 1 to 8.

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