Conductive silver paste, chip polymer laminated aluminum capacitor and preparation method of chip polymer laminated aluminum capacitor

Abstract

In order to solve the problem that the existing conductive silver paste is difficult to meet the requirements of low impedance and low volume, the invention provides the conductive silver paste which comprises silver powder, a first solvent and acrylic acid modified fluorine-containing epoxy resin, and the acrylic acid modified fluorine-containing epoxy resin contains an epoxy group, an acryloyloxypropyl group and a fluoroalkyl structure. Meanwhile, the invention further discloses a preparation method of the conductive silver paste and a chip type polymer laminated aluminum capacitor adopting the conductive silver paste. The conductive silver paste provided by the invention has relatively low impedance, and when the conductive silver paste is applied to the chip-type polymer laminated aluminum capacitor, the connection tightness between different capacitor single chips can be improved, the volume and equivalent series resistance of the capacitor can be reduced, and the electrochemical performance of the chip-type polymer laminated aluminum capacitor can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of capacitor materials, and in particular relates to a conductive silver paste, a chip-type polymer laminated aluminum capacitor and a preparation method thereof. Background Art

[0002] In recent years, with the continuous development of the electronic components industry, the demand for capacitors with small size, light weight, and excellent electrical performance has been increasing. As a new type of aluminum capacitor, polymer multilayer aluminum capacitors (MLPCs) offer advantages over traditional capacitors, such as high capacitance per unit volume, long life, high reliability, and compatibility with SMT processes. They are currently widely used in various fields, including servers, communication base stations, laptops, and industrial control motherboards.

[0003] With the expansion of application fields and the continuous improvement of application-end demand, the impedance and volume requirements for chip polymer multilayer aluminum capacitors (MLPC) have become increasingly stringent. The existing conductive silver paste is difficult to meet the requirements for further reduction in volume and ESR (equivalent series resistance) of chip polymer multilayer aluminum capacitors (MLPC). Summary of the Invention

[0004] Aiming at the problem that existing conductive silver paste is difficult to meet the requirements of low impedance and low volume, the present invention provides a conductive silver paste, a chip-type polymer laminated aluminum capacitor and a preparation method thereof.

[0005] The technical solutions adopted by the present invention to solve the above technical problems are as follows:

[0006] In one aspect, the present invention provides a conductive silver paste comprising silver powder, a first solvent and an acrylic modified fluorinated epoxy resin, wherein the acrylic modified fluorinated epoxy resin contains an epoxy group, an acryloxypropyl group and a fluoroalkyl structure.

[0007] Optionally, the acrylic modified fluorine-containing epoxy resin is obtained by copolymerizing raw materials including a fluorine-containing acrylic prepolymer and an epoxy resin.

[0008] Optionally, the mass ratio of the fluorine-containing acrylic prepolymer to the epoxy resin is (30-60):(70-40).

[0009] Optionally, the fluorine-containing acrylic prepolymer is obtained by copolymerizing raw materials including acrylic monomers and perfluoropolyether alcohol, and the mass ratio of the acrylic monomers to the perfluoropolyether alcohol is (93-96):(7-4).

[0010] Optionally, the acrylic monomer includes one or more of methyl methacrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, dodecafluoroheptyl methacrylate, lauryl acrylate, octadecyl acrylate, methacrylate, ethyl acetoacetate methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, γ-methacryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltris(β-trimethoxyethoxysilane);

[0011] The perfluoropolyether alcohol includes one or more of K-type perfluoropolyether alcohol, Y-type perfluoropolyether alcohol, Z-type perfluoropolyether alcohol, D-type perfluoropolyether alcohol, and modified perfluoropolyether alcohol.

[0012] Optionally, the epoxy resin includes one or more of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0013] Optionally, the conductive silver paste includes the following components by weight:

[0014] 30-70 parts of silver powder, 10-45 parts of the first solvent and 5-10 parts of acrylic acid-modified fluorine-containing epoxy resin.

[0015] On the other hand, the present invention provides a chip-type polymer laminated aluminum capacitor, including a capacitor core, wherein the capacitor core includes multiple capacitor monoliths, the outer layer of the capacitor monoliths is a conductive silver layer, and the multiple capacitor monoliths are interconnected and combined by the conductive silver layer, and the conductive silver layer is obtained by curing the conductive silver paste as described above.

[0016] On the other hand, the present invention provides a method for preparing the conductive silver paste as described above, comprising the following steps:

[0017] Putting the fluorinated acrylic prepolymer and the epoxy resin into a second solvent, stirring, and adding a curing agent dropwise to react to obtain an acrylic modified fluorinated epoxy resin;

[0018] The acrylic modified fluorine-containing epoxy resin, silver powder and the first solvent are dispersed and mixed to obtain a conductive silver paste.

[0019] Optionally, the preparation method of the fluorine-containing acrylic prepolymer includes the following steps:

[0020] The acrylic monomer, perfluoropolyether alcohol and acid catalyst are added into a third solvent for reaction, and then washed with water to obtain a fluorine-containing acrylic prepolymer.

[0021] The conductive silver paste provided by the present invention uses an acrylic acid-modified fluorinated epoxy resin containing epoxy groups, acryloxypropyl groups, and fluoroalkyl groups as a temperature-sensitive organic resin. The acrylic acid-modified fluorinated epoxy resin has good compatibility with silver powder. The acryloxypropyl groups and epoxy groups react with each other to form an interpenetrating network polymer, which can promote the uniform dispersion of silver powder and improve the compatibility between the resin and silver powder, thereby reducing impedance. In addition, the perfluoropolyether chain segments doped in the acrylic acid have high flexibility and low electrolyte swelling rate. Therefore, when the conductive silver paste is applied to a chip-type polymer laminated aluminum capacitor, it can improve the connection tightness between different capacitor monoliths, reduce the capacitor volume and equivalent series resistance, and improve the electrochemical performance of the chip-type polymer laminated aluminum capacitor. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0023] An embodiment of the present invention provides a conductive silver paste, including silver powder, a first solvent, and an acrylic acid-modified fluorinated epoxy resin, wherein the acrylic acid-modified fluorinated epoxy resin contains an epoxy group, an acryloxypropyl group, and a fluoroalkyl structure.

[0024] An acrylic acid-modified fluorinated epoxy resin containing epoxy groups, acryloxypropyl groups, and fluoroalkyl groups is used as a temperature-sensitive organic resin. This acrylic acid-modified fluorinated epoxy resin has good compatibility with silver powder. The acryloxypropyl groups and epoxy groups react with each other to form an interpenetrating network polymer, which can effectively prevent the sedimentation of the silver powder and promote the uniform dispersion of the silver powder, thereby reducing the impedance. In addition, the perfluoropolyether chain segments doped in the acrylic acid have high flexibility and low electrolyte swelling rate. Therefore, when the conductive silver paste is applied to a chip-type polymer laminated aluminum capacitor, the connection tightness between different capacitor chips can be improved, the capacitor volume and equivalent series resistance can be reduced, and the electrochemical performance of the chip-type polymer laminated aluminum capacitor can be improved.

[0025] In some embodiments, the acrylic modified fluorine-containing epoxy resin is obtained by copolymerizing raw materials including a fluorine-containing acrylic prepolymer and an epoxy resin.

[0026] The chain segments between the fluorine-containing acrylic prepolymer and the epoxy resin penetrate each other through cross-linking, so that the silver powder can be more evenly dispersed in the acrylic modified fluorine-containing epoxy resin, thereby reducing the contact resistance between the silver powders.

[0027] In some embodiments, the mass ratio of the fluorine-containing acrylic prepolymer to the epoxy resin is (30-60): (70-40).

[0028] When the proportion of fluorinated acrylic prepolymer in the acrylic-modified fluorinated epoxy resin is too low, its dispersion performance for silver powder decreases. At the same time, the conductive silver layer prepared by the conductive silver paste has a certain swelling property and insufficient toughness, which leads to an increase in the impedance between different capacitor chips and an increase in the overall thickness of the capacitor. When the proportion of epoxy resin in the acrylic-modified fluorinated epoxy resin is too low, the heat resistance of the conductive silver layer prepared by the conductive silver paste decreases, which is not conducive to the safety of the capacitor at high temperatures.

[0029] In some embodiments, the fluorine-containing acrylic prepolymer is obtained by copolymerizing raw materials including acrylic monomers and perfluoropolyether alcohol, and the mass ratio of the acrylic monomers to the perfluoropolyether alcohol is (93-96): (7-4).

[0030] When the proportion of acrylic monomers in the fluorinated acrylic prepolymer is too low, the compatibility of the fluorinated acrylic prepolymer with the epoxy resin decreases, and the fluorinated acrylic prepolymer and the epoxy resin are likely to be delaminated, affecting the dispersion effect of the silver powder; when the proportion of perfluoropolyether alcohol in the fluorinated acrylic prepolymer is too low, the conductive silver layer prepared by the conductive silver paste has a certain swelling problem in the electrolyte of the capacitor, resulting in an increase in the thickness of the capacitor and an increase in impedance.

[0031] In some embodiments, the acrylic monomer includes one or more of methyl methacrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, dodecafluoroheptyl methacrylate, lauryl acrylate, octadecyl acrylate, methacrylate, ethyl acetoacetate methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyltris(β-trimethoxyethoxysilane).

[0032] In some embodiments, the perfluoropolyether alcohol includes one or more of K-type perfluoropolyether alcohol, Y-type perfluoropolyether alcohol, Z-type perfluoropolyether alcohol, D-type perfluoropolyether alcohol, and modified perfluoropolyether alcohol.

[0033] In some embodiments, the epoxy resin includes one or more of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0034] In some embodiments, the conductive silver paste includes the following components by weight:

[0035] 30-70 parts of silver powder, 10-45 parts of the first solvent and 5-10 parts of acrylic acid-modified fluorine-containing epoxy resin.

[0036] In some embodiments, the silver powder includes one or more of flake silver powder and spherical silver powder.

[0037] In some embodiments, the first solvent is selected from one or more of esters, ethers, and ketones.

[0038] Another embodiment of the present invention provides a chip-type polymer laminated aluminum capacitor, including a capacitor core, wherein the capacitor core includes multiple capacitor monoliths, the outer layer of the capacitor monoliths is a conductive silver layer, and the multiple capacitor monoliths are interconnected and combined by the conductive silver layer, and the conductive silver layer is obtained by curing the conductive silver paste as described above.

[0039] Due to the use of the conductive silver paste, the polymer laminated aluminum chip capacitor has lower equivalent series resistance and lower thickness.

[0040] Another embodiment of the present invention provides a packaging method for the above-mentioned chip-type polymer laminated aluminum capacitor, comprising the following steps:

[0041] Obtain a single sheet of aluminum foil having a surface impregnated with a conductive polymer; impregnate it with a conductive carbon slurry (such as SuC-203) through a dipping process; impregnate it with the conductive silver paste described above through a dipping process; cut the single sheet and laminate it into layers through extrusion molding; plastic-encapsulate the laminated product; and test it to obtain a chip-type polymer laminated aluminum capacitor.

[0042] Another embodiment of the present invention provides a method for preparing the conductive silver paste as described above, comprising the following steps:

[0043] Putting the fluorinated acrylic prepolymer and the epoxy resin into a second solvent, stirring, and adding a curing agent dropwise to react to obtain an acrylic modified fluorinated epoxy resin;

[0044] The acrylic modified fluorine-containing epoxy resin, silver powder and the first solvent are dispersed and mixed to obtain a conductive silver paste.

[0045] In some embodiments, the method for preparing the fluorinated acrylic prepolymer comprises the following steps:

[0046] The acrylic monomer, perfluoropolyether alcohol and acid catalyst are added into a third solvent for reaction, and then washed with water to obtain a fluorine-containing acrylic prepolymer.

[0047] In some embodiments, the acid catalyst includes one or more of hydrochloric acid, sulfuric acid, and trifluoromethanesulfonic acid.

[0048] In some embodiments, in the preparation of the fluorine-containing acrylic prepolymer, the reaction temperature is 70-100° C., and the reaction time is 5-10 h.

[0049] In some embodiments, the curing agent includes one or more of amines, amides, acid anhydrides, polyphenols, and polymeric thiols.

[0050] In a preferred embodiment, the curing agent is selected from amine compounds. In a more preferred embodiment, the curing agent includes one or more of polyamide compounds, aliphatic amine compounds, aromatic amine compounds, alicyclic amine compounds, polyether amines and imidazole compounds.

[0051] In some embodiments, the imidazole compound includes one or more of 1-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-cyano-ethyl-4-methylimidazole, and 1-cyanoethyl-2-phenylimidazole.

[0052] In some embodiments, the second solvent and the third solvent are each independently selected from an ether solvent or an ester solvent.

[0053] In some embodiments, the second solvent and the third solvent are each independently selected from one or more of ethyl acetate, propyl acetate, butyl acetate, ethyl lactate, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, diethylene glycol methyl ether acetate, diethylene glycol ethyl ether acetate, diethylene glycol butyl ether acetate, propylene glycol methyl ether acetate, DBE, methyl perfluorobutyl ether, ethyl perfluorobutyl ether, and 3-methoxyperfluorohexane.

[0054] In some embodiments, the reaction temperature of the fluorinated acrylic prepolymer and the epoxy resin is 50-120° C., and the reaction time is 5-24 hours.

[0055] The present invention is further described below with reference to the following examples.

[0056] Example 1

[0057] This embodiment is used to illustrate the conductive silver paste and its preparation method disclosed in the present invention, including the following operations:

[0058] In a 500mL four-necked flask equipped with a thermometer, mechanical stirring, reflux condenser, and constant pressure dropping funnel, 30g of methacrylic acid, 1.1g of Z-type perfluoropolyether alcohol (molecular weight 1000), and 0.1g of concentrated sulfuric acid (30%) were added in sequence in a mixed solvent of 10g of hydrofluoroether and 35g of ethylene glycol monobutyl ether, and the mixture was reacted at 70°C for 8h and then heated to 100°C for 2h. After the reaction, the product W1 was recorded after washing with water and removing the low boiling point on a rotary evaporator. 50 g of product W1, 100 g of commercially available epoxy resin with an epoxy equivalent of 150 g / eq, and 100 g of diethylene glycol butyl ether acetate were stirred in an 80°C oil bath for 60 minutes until all dissolved. Then, a mixture of 1.5 g of 1-methylimidazole and 20 g of diethylene glycol butyl ether acetate was dropped into the reaction flask within 20 minutes. The liquid temperature was controlled not to exceed 85°C during the addition process. After the addition was completed, the liquid temperature was controlled at 80-82°C and the reaction was carried out for 12 hours. During the reaction, the viscosity of the system continued to increase, and a transparent product was obtained after the reaction was completed. 5 g of the product was taken and placed in an aluminum pan with a diameter of 90 cm and baked at 150°C for 60 min. The solid content of the tested product was recorded as M1, and the obtained acrylic acid-modified fluorinated epoxy resin was marked as A1. Silver powder, acrylic acid-modified fluorinated epoxy resin A1 and ethyl acetate were mixed in a mass ratio of 50:5:45 to obtain a conductive silver paste.

[0059] Example 2

[0060] This embodiment is used to illustrate the conductive silver paste and its preparation method disclosed in the present invention, including the following operations:

[0061] In a 500mL four-necked flask equipped with a thermometer, mechanical stirring, reflux condenser, and constant pressure dropping funnel, 30g of acrylic acid, 2.0g of type D perfluoropolyether alcohol (molecular weight 2000), and 0.15g of concentrated sulfuric acid (30%) were added in sequence in a mixed solvent of 10g of hydrofluoroether and 35g of propylene glycol methyl ether acetate, and the mixture was reacted at 80°C for 5h. After the reaction is completed, the product W2 is recorded after washing with water and removing the low boiling point on a rotary evaporator. 50g of product W2, 100g of commercially available epoxy resin with an epoxy equivalent of 150g / eq, and 150g of diethylene glycol ethyl ether acetate are stirred in a 50°C oil bath for 10 minutes. Then, a mixture of 0.8g of 2-cyano-ethyl-4-methylimidazole and 50g of diethylene glycol ethyl ether acetate is dropped into the reaction flask within 20 minutes. The liquid temperature is controlled not to exceed 55°C during the addition process. After the addition is completed, the liquid temperature is controlled at 50-52°C and the reaction is carried out for 24 hours. During the reaction, the viscosity of the system continued to increase, and a transparent product was obtained after the reaction was completed. 5 g of the product was taken and placed in an aluminum pan with a diameter of 90 cm and baked at 150°C for 60 min. The solid content of the tested product was recorded as M2, and the obtained acrylic acid-modified fluorinated epoxy resin was marked as A2. Silver powder, acrylic acid-modified fluorinated epoxy resin A2 and ethyl acetate were mixed in a mass ratio of 50:5:45 to obtain a conductive silver paste.

[0062] Example 3

[0063] This embodiment is used to illustrate the conductive silver paste and its preparation method disclosed in the present invention, including the following operations:

[0064] In a 500mL four-necked flask equipped with a thermometer, mechanical stirring, reflux condenser, and constant pressure dropping funnel, 30g of methacrylic acid, 1.1g of Z-type perfluoropolyether alcohol (molecular weight 1000), and 0.10g of concentrated sulfuric acid (30%) were added in sequence in a mixed solvent of 10g of hydrofluoroether and 35g of ethylene glycol monobutyl ether, and the mixture was reacted at 70°C for 8h. After the reaction is completed, the product W3 is recorded after washing with water and removing the low boiling point on a rotary evaporator. 50 g of product W3, 100 g of a commercially available epoxy resin with an epoxy equivalent of 450 g / eq, and 150 g of diethylene glycol monobutyl ether are stirred in a 65°C oil bath for 60 minutes until all are dissolved. Then, a mixture of 1.0 g of 2-ethyl-4-methylimidazole and 50 g of diethylene glycol monobutyl ether is added dropwise to the reaction flask within 20 minutes. The liquid temperature is controlled not to exceed 70°C during the addition process. After the addition is completed, the liquid temperature is controlled at 60-62°C and the reaction is carried out for 8 hours. During the reaction, the viscosity of the system continued to increase, and a transparent product was obtained after the reaction was completed. 5 g of the product was taken and placed in an aluminum pan with a diameter of 90 cm and baked at 150°C for 60 min. The solid content of the tested product was recorded as M3, and the obtained acrylic acid-modified fluorinated epoxy resin was marked as A3. Silver powder, acrylic acid-modified fluorinated epoxy resin A3 and ethyl acetate were mixed in a mass ratio of 50:5:45 to obtain a conductive silver paste.

[0065] Comparative Example 1

[0066] This comparative example provides a commercially available conductive silver paste.

[0067] Comparative Example 2

[0068] This comparative example is used to illustrate the preparation method of the conductive silver paste disclosed in the present invention, which includes the following operations:

[0069] To a 500mL four-necked flask equipped with a thermometer, mechanical stirring, reflux condenser, and constant pressure dropping funnel, 30g of methacrylic acid and 3.3g of ammonium persulfate were added sequentially. The mixture was reacted at 75°C for 8h in the presence of 35g of water and 10g of isopropyl alcohol. After reaction, 4.3% sulfuric acid (30%) was added and stirred for 1h. After completion of the reaction, the mixture was washed with water and de-boiling on a rotary evaporator, which was recorded as product W4. 50g of product W4, 100g of a commercially available epoxy resin with an epoxy equivalent weight of 150g / eq, and 100g of ethylene glycol butyl ether acetate were stirred in an 80°C oil bath for 60 minutes until complete dissolution. A mixture of 1.9g of 1-methylimidazole and 20g of diethylene glycol butyl ether acetate was then added dropwise to the reaction flask over 20 minutes. The liquid temperature was maintained above 85°C during the addition. After the addition was complete, the liquid temperature was maintained between 80-82°C and allowed to react for 12h. During the reaction, the viscosity of the system continued to increase, and a transparent product was obtained after the reaction was completed. 5 g of the product was taken and placed in an aluminum pan with a diameter of 90 cm and baked at 150°C for 60 min. The solid content of the tested product was recorded as M4, and the obtained acrylic acid-modified epoxy resin was marked as A4. Silver powder, acrylic acid-modified epoxy resin A4 and ethyl acetate were mixed in a mass ratio of 50:5:45 to obtain a conductive silver paste.

[0070] Performance Testing

[0071] 1. The viscosity and square resistance of the conductive silver paste prepared above were tested to obtain the test results; 2. The conductive silver paste prepared above was used to prepare a chip polymer laminated aluminum capacitor by the following method and tested: the surface of an aluminum foil monolithic sheet was impregnated with a conductive polymer; then, a conductive carbon slurry was impregnated through an impregnation process; a capacitor monolithic sheet was impregnated with the conductive silver paste described above through an impregnation process; the capacitor monolithic sheet was cut and laminated and extruded; the laminated product was plastic-sealed; a chip polymer laminated aluminum capacitor was obtained, and the thickness, impedance ESR, and leakage current LC of the chip polymer laminated aluminum capacitor were tested, and the impedance ESR of the chip polymer laminated aluminum capacitor after baking at 270°C for 3 minutes was tested, and the test results were filled in Table 1.

[0072] Table 1

[0073]

[0074] It can be seen from the test results in Table 1 that the conductive silver paste prepared by the preparation method provided by the present invention has a lower square resistance. At the same time, the chip-type polymer laminated aluminum capacitor prepared by the conductive silver paste provided by the present invention has a lower thickness and impedance, which can effectively reduce the volume and electrochemical performance of the chip-type polymer laminated aluminum capacitor.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A conductive silver paste, characterized in that: The invention comprises silver powder, a first solvent and an acrylic modified fluorine-containing epoxy resin, wherein the acrylic modified fluorine-containing epoxy resin contains an epoxy group, an acryloxypropyl group and a fluoroalkyl structure.

2. The conductive silver paste according to claim 1, characterized in that The acrylic modified fluorine-containing epoxy resin is obtained by copolymerizing raw materials including a fluorine-containing acrylic prepolymer and an epoxy resin.

3. The conductive silver paste according to claim 2, characterized in that The mass ratio of the fluorine-containing acrylic prepolymer to the epoxy resin is (30-60):(70-40).

4. The conductive silver paste according to claim 2, characterized in that The fluorine-containing acrylic prepolymer is obtained by copolymerizing raw materials including acrylic monomers and perfluoropolyether alcohol, and the mass ratio of the acrylic monomers to the perfluoropolyether alcohol is (93-96): (7-4).

5. The conductive silver paste according to claim 4, characterized in that The acrylic monomers include one or more of methyl methacrylate, ethyl acrylate, butyl acrylate, isooctyl acrylate, hexafluorobutyl acrylate, hexafluorobutyl methacrylate, dodecafluoroheptyl methacrylate, lauryl acrylate, octadecyl acrylate, methacrylate, ethyl acetoacetate methacrylate, glycidyl methacrylate, dimethylaminoethyl methacrylate, γ-methacryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltris(β-trimethoxyethoxysilane); The perfluoropolyether alcohol includes one or more of K-type perfluoropolyether alcohol, Y-type perfluoropolyether alcohol, Z-type perfluoropolyether alcohol, D-type perfluoropolyether alcohol, and modified perfluoropolyether alcohol.

6. The conductive silver paste according to claim 2, characterized in that The epoxy resin includes one or more of bisphenol A epoxy resin and bisphenol F epoxy resin.

7. The conductive silver paste according to claim 1, characterized in that The conductive silver paste comprises the following components by weight: 30-70 parts of silver powder, 10-45 parts of the first solvent and 5-10 parts of acrylic acid-modified fluorine-containing epoxy resin.

8. A chip-type polymer laminated aluminum capacitor, characterized in that: The invention comprises a capacitor core, wherein the capacitor core comprises a plurality of capacitor monoliths, wherein the outer layer of the capacitor monoliths is a conductive silver layer, and the plurality of capacitor monoliths are interconnected and combined by the conductive silver layer, wherein the conductive silver layer is obtained by curing the conductive silver paste according to any one of claims 1 to 7.

9. The method for preparing a conductive silver paste according to any one of claims 1 to 7, wherein: The following steps are included: Putting the fluorinated acrylic prepolymer and the epoxy resin into a second solvent, stirring, and adding a curing agent dropwise to react to obtain an acrylic modified fluorinated epoxy resin; The acrylic modified fluorine-containing epoxy resin, silver powder and the first solvent are dispersed and mixed to obtain a conductive silver paste.

10. The method for preparing the conductive silver paste according to claim 9, wherein: The preparation method of the fluorine-containing acrylic prepolymer comprises the following steps: The acrylic monomer, perfluoropolyether alcohol and acid catalyst are added into a third solvent for reaction, and then washed with water to obtain a fluorine-containing acrylic prepolymer.

Images