Phosphate modified polysiloxane as well as preparation method and application thereof

Abstract

The invention provides phosphate-modified polysiloxane as well as a preparation method and application thereof. The phosphate-modified polysiloxane comprises at least one of compounds shown in a structural formula I. The phosphate-modified polysiloxane can be used as a flatting agent for preparing adhesive silver paste for a capacitor. The phosphate modified polysiloxane can effectively improve the compatibility between the silver powder and the resin in the bonding silver paste, thereby improving the leveling property of the silver paste. Meanwhile, the phosphate modified polysiloxane has larger adhesive force with a base material, and the situation that the leveling agent migrates to the surface of the conductive film layer in the curing process and consequently the electrical property becomes poor is avoided, so that the bonding silver paste for the capacitor with excellent leveling property and high conductivity (low ESR) is prepared.

Description

Technical Field

[0001] This invention belongs to the field of capacitor technology, specifically relating to a phosphate-modified polyorganosiloxane, its preparation method, and its application. Background Technology

[0002] Polymer multilayer aluminum capacitors (MLPCs) are a new type of aluminum capacitor. They utilize a high-conductivity polymer material as the cathode, which is then impregnated with carbon paste and silver to form unit cells. These unit cells are then bonded together with silver paste, and finally encapsulated with epoxy resin to complete the MLPC. With the development of electronic technology and components, low power consumption and high-speed processing are the development trends of modern electronic devices, which places higher demands on the performance of MLPC capacitors. Low-ESR aluminum multilayer capacitors are a hot research topic, and the bonding silver, as a crucial component, directly affects the interface impedance between unit cells and between unit cells and the lead frame.

[0003] Currently, high-viscosity bonding silver paste for capacitors has requirements regarding fluidity. The addition of leveling and dispersing agents in existing technologies can improve the fluidity of the silver paste, but the leveling agents are prone to migrate to the surface of the silver layer during the curing process, which can reduce the electrical properties (sheet resistance, resistivity, or conductivity) of the silver paste, directly causing the capacitor's ESR to be too high, making it unsuitable for high-performance MLPC capacitors. Summary of the Invention

[0004] Based on this, the purpose of the present invention is to provide a phosphate-modified polyorganosiloxane, its preparation method and application, wherein the phosphate-modified polyorganosiloxane can be used as a leveling agent to prepare adhesive silver paste for capacitors, thereby improving the relevant performance of capacitors.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] A first aspect of the present invention provides a phosphate-modified polyorganosiloxane comprising at least one of the compounds shown in structural formula I:

[0007]

[0008] Wherein, R1, R2, and R3 are independently selected from methyl, ethyl, and phenyl; R4 and R5 are independently selected from hydrogen, methyl, ethyl, butyl, glyceryl, 2-ethylhexyl, and isooctyl, and at least one of R4 and R5 is not hydrogen; a and b are integers and 2≤a≤20, 2≤b≤20. a and b are the degrees of polymerization.

[0009] In a second aspect, the present invention provides a method for preparing the phosphate-modified polyorganosiloxane as described above, comprising the following steps: (1) taking diekoxysilane and a capping agent as organosilicon monomers, and performing a co-hydrolysis condensation reaction at 40°C to 80°C under the dispersion of water and water-soluble organic solvent and the action of an acid catalyst; after the reaction is completed, removing the acid catalyst, then extracting and separating the organic layer, washing the organic layer with water until neutral, and distilling under reduced pressure to obtain a hydroxyl organosiloxane oligomer solution;

[0010] (2) The hydroxyl organosiloxane oligomer solution is mixed evenly with phosphate ester and condensation reaction is carried out at 70℃~100℃. The reaction product is distilled under reduced pressure to obtain the phosphate ester modified polyorganosiloxane.

[0011] In some embodiments, the reaction time in step (1) is 3h to 5h.

[0012] In some embodiments, the temperature of the vacuum distillation in step (1) is 80-100°C.

[0013] In some embodiments, the reaction time in step (2) is 4h to 10h.

[0014] In some embodiments, the temperature of vacuum distillation in step (2) is 90°C to 120°C.

[0015] In some embodiments, the molar number of the dialkoxysilane is 85% to 95% of the molar number of the organosilicon monomer, preferably 90% to 95%.

[0016] In some embodiments, the molar number of the capping agent is 5% to 15% of the molar number of the organosilicon monomer, preferably 5% to 10%.

[0017] In some embodiments, the mass of the water-soluble organic solvent is 0.3 to 0.9 times the mass of the organosilicon monomer, preferably 0.4 to 0.6 times, and more preferably 0.5 times.

[0018] In some embodiments, the number of moles of water is 1 to 3 times the number of moles of hydrolyzable groups of the organosilicon monomer, preferably 1.5 to 2 times.

[0019] In some embodiments, the mass ratio of the acid catalyst to the water is (0.5:99.5) to (10:90).

[0020] In some embodiments, the mass of the phosphate ester is 10% to 15% of the mass of the hydroxyl organosiloxane oligomer solution, preferably 12% to 13%.

[0021] In some embodiments, the dialkoxysilane is a hydrocarbon dialkoxysilane, wherein the hydrocarbon dialkoxysilane is selected from at least one of methylphenyldimethoxysilane, diphenyldimethoxysilane, methylphenyldiethoxysilane, diphenyldiethoxysilane, dimethyldimethoxysilane, and dimethyldiethoxysilane.

[0022] In some embodiments, the capping agent is selected from at least one of hexamethyldisiloxane and trimethylmethoxysilane.

[0023] In some embodiments, the phosphate ester is selected from at least one of monophosphate and diester, wherein the monophosphate includes monobutyl phosphate, 2-ethylhexyl phosphate, isooctyl phosphate, and glycerophosphate; and the diester includes dimethyl phosphate, diethyl phosphate, and dibutyl phosphate.

[0024] In some embodiments, the water-soluble organic solvent is selected from at least one of methanol, ethanol, and isopropanol.

[0025] In some embodiments, the acid catalyst is selected from at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, trifluoromethanesulfonic acid, acetic acid, oxalic acid, p-toluenesulfonic acid, and acid clay.

[0026] In some embodiments, the extractant used in the extraction is selected from at least one of ethyl acetate, methyl acetate, ethyl propionate, toluene, and xylene.

[0027] A third aspect of the present invention provides the use of the phosphate-modified polyorganosiloxane as described above or the phosphate-modified polyorganosiloxane prepared by the preparation method as described above in the preparation of adhesive silver paste for capacitors.

[0028] In a fourth aspect, the present invention provides an adhesive silver paste for capacitors, which is prepared from the following raw materials in parts by weight: 5 to 15 parts resin, 55 to 75 parts silver powder, 0.1 to 1.5 parts of phosphate-modified polyorganosiloxane as described above or phosphate-modified polyorganosiloxane prepared by the method described above, and 10 to 30 parts solvent.

[0029] In some embodiments, the resin is selected from at least one of acrylic resin, epoxy resin, vinyl chloride resin, polyurethane resin, and polyester resin.

[0030] In some embodiments, the silver powder is selected from at least one of spherical silver with a particle size of 0.5 μm to 10 μm and flake silver with a particle size of 1 μm to 15 μm, and the surface of the silver powder is treated with oleic acid or stearic acid.

[0031] In some embodiments, the solvent is selected from two or more of butyl acetate, propylene glycol methyl ether acetate, ethylene glycol butyl ether, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, and diethylene glycol butyl ether acetate.

[0032] A fifth aspect of the present invention provides a method for preparing the adhesive silver paste for capacitors as described above, comprising the following steps: taking each raw material, stirring and dispersing it evenly, then grinding it, and finally dispersing and stirring it to obtain the adhesive silver paste for capacitors.

[0033] In some embodiments, a three-roll mill is used for grinding.

[0034] In a sixth aspect, the present invention provides a capacitor, wherein the raw materials for manufacturing the capacitor include the bonding silver paste as described above.

[0035] In some embodiments, the capacitor is an aluminum capacitor; preferably, the capacitor is a chip polymer multilayer aluminum capacitor.

[0036] This invention provides a phosphate-modified polyorganosiloxane, obtained by modifying a polyorganosiloxane by introducing a phosphate ester. The inventors have discovered that the phosphate-modified polyorganosiloxane can effectively improve the compatibility between silver powder and resin in adhesive silver paste, thereby improving the leveling properties of the silver paste. Simultaneously, the phosphate-modified polyorganosiloxane exhibits greater adhesion to the substrate, preventing the leveling agent from migrating to the conductive film surface during curing and thus avoiding deterioration of electrical properties. The phosphate-modified polyorganosiloxane of this invention can be used to prepare adhesive silver paste for capacitors with excellent leveling properties and high conductivity (low ESR). Detailed Implementation

[0037] Unless otherwise specified, the experimental methods described in the following embodiments of the present invention are generally performed under conventional conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the embodiments are commercially available products.

[0038] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0039] The terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or device that includes a series of steps is not limited to the steps or modules listed, but may optionally include steps not listed, or may optionally include other steps inherent to such process, method, product, or device.

[0040] In this invention, "at least one" refers to one or more. "And / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0041] The following description is based on specific embodiments.

[0042] Example 1

[0043] This embodiment provides a phosphate-modified polyorganosiloxane, which is prepared by the following method:

[0044] In a 2L four-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and constant-pressure dropping funnel, 500g of dimethyldimethoxysilane, 40g of hexamethyldisiloxane monomer, and 100g of ethanol were added sequentially. The mixture was stirred in a 40℃ oil bath for 10 minutes. Then, over 20 minutes, a mixture of 17.6g of concentrated sulfuric acid and 208g of deionized water was added dropwise into the reaction flask. During the addition, the temperature of the solution in the reaction flask was controlled to not exceed 65℃. After the addition was completed, the system temperature was controlled at 72± The reaction was carried out at 1℃ for 5 hours. 400g of xylene was added as an extractant. The acid catalyst was removed by washing with pure water. The organic layer was separated and repeatedly washed with water until neutral. The solution of colorless and transparent hydroxyl organosiloxane oligomer was obtained by vacuum distillation at 80℃. Then, 50g of monobutyl phosphate was added and the reaction was continued in an oil bath at 85℃ with stirring for 8 hours. After the reaction was completed, the solvent and low molecular weight substances were removed by vacuum distillation at 110℃ to obtain phosphate-modified polyorganosiloxane leveling agent 1.

[0045] Example 2

[0046] This embodiment provides a phosphate-modified polyorganosiloxane, which is prepared by the following method:

[0047] In a 2L four-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and constant-pressure dropping funnel, 500g of methylphenyldimethoxysilane, 35g of trimethylmethoxysilane monomer, and 100g of ethanol were added sequentially. The mixture was stirred in a 40℃ oil bath for 10 minutes. Then, over 20 minutes, a mixture of 16.2g of concentrated sulfuric acid and 200g of deionized water was added dropwise into the reaction flask. During the addition, the temperature of the solution in the reaction flask was controlled to not exceed 65℃. After the addition was completed, the system temperature was controlled at 75℃. The reaction was carried out at ±1℃ for 5 hours. 400g of xylene was added as an extractant. The acid catalyst was removed by washing with pure water. The organic layer was separated and repeatedly washed with water until neutral. The solution of colorless and transparent hydroxyl organosiloxane oligomer was obtained by vacuum distillation at 85℃. Then, 40g of dibutyl phosphate was added and the reaction was continued in an oil bath at 85℃ with stirring for 8 hours. After the reaction was completed, the solvent and low molecular weight substances were removed by vacuum distillation at 100℃ to obtain phosphate-modified polyorganosiloxane leveling agent 2.

[0048] Example 3

[0049] This embodiment provides a phosphate-modified polyorganosiloxane, which is prepared by the following method:

[0050] In a 2L four-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and constant-pressure dropping funnel, 500g of diphenyldimethoxysilane, 30g of trimethylmethoxysilane monomer, and 100g of isopropanol were added sequentially. The mixture was stirred in a 40℃ oil bath for 10 minutes. Then, over 20 minutes, a mixture of 15.0g hydrochloric acid and 200g deionized water was added dropwise into the reaction flask. During the addition, the temperature of the solution in the reaction flask was controlled to not exceed 65℃. After the addition was completed, the system temperature was controlled at 70±1℃. After reacting internally for 5 hours, 400 g of xylene was added as an extractant. The acid catalyst was removed by washing with pure water, the organic layer was separated, and the organic layer was repeatedly washed with water until neutral. The solution of colorless and transparent hydroxyl organosiloxane oligomer was obtained by vacuum distillation at 85°C. Then, 40 g of 2-ethylhexyl phosphate was added, and the reaction was continued to be stirred in an oil bath at 85°C for 8 hours. After the reaction was completed, the solvent and low molecular weight substances were removed by vacuum distillation at 110°C to obtain phosphate-modified polyorganosiloxane leveling agent 3.

[0051] Example 4

[0052] This embodiment provides a phosphate-modified polyorganosiloxane, which is prepared by the following method:

[0053] In a 2L four-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and constant-pressure dropping funnel, 500g of methylphenyldiethoxysilane, 38g of hexamethyldisiloxane monomer, and 90g of methanol were added sequentially. The mixture was stirred in a 40℃ oil bath for 10 minutes. Then, over 20 minutes, a mixture of 15.5g of concentrated sulfuric acid and 200g of deionized water was added dropwise into the reaction flask. During the addition, the temperature of the solution in the reaction flask was controlled to not exceed 65℃. After the addition was completed, the system temperature was controlled at 70±1℃. The reaction was carried out at ℃ for 5 hours. 400g of xylene was added as an extractant. The acid catalyst was removed by washing with pure water. The organic layer was separated and repeatedly washed with water until neutral. The solution of colorless and transparent hydroxyl organosiloxane oligomer was obtained by vacuum distillation at 85℃. Then, 40g of isooctyl phosphate was added and the reaction was continued in an oil bath at 85℃ with stirring for 9 hours. After the reaction was completed, the solvent and low molecular weight substances were removed by vacuum distillation at 105℃ to obtain phosphate-modified polyorganosiloxane leveling agent 4.

[0054] Example 5

[0055] This embodiment provides a phosphate-modified polyorganosiloxane, which is prepared by the following method:

[0056] In a 2L four-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and constant-pressure dropping funnel, 500g of dimethyldiethoxysilane, 35g of trimethylmethoxysilane monomer, and 100g of ethanol were added sequentially. The mixture was stirred in a 40℃ oil bath for 10 minutes. Then, over 20 minutes, a mixture of 14.5g concentrated sulfuric acid and 200g deionized water was added dropwise into the reaction flask. During the addition, the temperature of the solution in the reaction flask was controlled to not exceed 65℃. After the addition was completed, the system temperature was controlled at 75± The reaction was carried out at 1℃ for 5 hours. 400g of xylene was added as an extractant. The acid catalyst was removed by washing with pure water. The organic layer was separated and repeatedly washed with water until neutral. The solution of colorless and transparent hydroxyl organosiloxane oligomer was obtained by vacuum distillation at 85℃. Then, 40g of glycerol phosphate was added and the reaction was continued in an oil bath at 85℃ with stirring for 8 hours. After the reaction was completed, the solvent and low molecular weight substances were removed by vacuum distillation at 100℃ to obtain phosphate-modified polyorganosiloxane leveling agent 5.

[0057] Example 6

[0058] This embodiment provides a bonding silver paste for capacitors. The raw materials for preparing the bonding silver paste include the phosphate ester modified polyorganosiloxane leveling agent 1 obtained in Example 1, which is specifically prepared from the following parts by weight: 10 parts resin, 65 parts silver powder, 0.3 parts leveling agent 1, and 24.7 parts solvent. The surface of the silver powder is treated with oleic acid or stearic acid.

[0059] The bonding silver paste is prepared by the following method: weigh each raw material according to the proportion, stir and disperse it evenly, then grind it with a three-roll mill, and finally disperse and stir to obtain the bonding silver paste.

[0060] Examples 7-10

[0061] Examples 7-10 illustrate the adhesive silver paste and its preparation method disclosed in this invention. Most of the operations are the same as in Example 6, as shown in Table 1. The preparation method is the same as in Example 6.

[0062] Comparative Examples 1-3

[0063] Comparative Examples 1 to 3 are used to illustrate the adhesive silver paste and its preparation method disclosed in this invention. Most of their operations are the same as those in Example 6, as shown in Table 1. The preparation method is the same as that in Example 6.

[0064] Table 1

[0065]

[0066]

[0067] Performance testing

[0068] The bonding silver paste prepared above was subjected to the following performance tests:

[0069] (1) Perform viscosity test on the bonding silver paste (viscosity test standard: GB / T2794);

[0070] (2) The flow rate of the adhesive silver paste was tested in a stainless steel groove with an inclination angle of 30°.

[0071] (3) Volume resistivity: The volume resistivity of the cured adhesive silver paste film (30um thick) was measured using a volume resistivity tester.

[0072] (4) Use 2V470uf aluminum foil to prepare capacitor single pieces. The surface of the capacitor single pieces that have been impregnated with carbon paste and silver paste is coated or dotted with adhesive silver paste. The five layers are stacked to obtain a chip polymer multilayer aluminum capacitor. The equivalent series resistance (ESR) of the chip polymer multilayer aluminum capacitor is tested respectively.

[0073] Table 2 below shows the test results:

[0074] Table 2

[0075]

[0076] As can be seen from the test results in Table 2 above, the bonding silver paste prepared using the phosphate-modified polyorganosiloxane prepared in this invention as a leveling agent can enable chip polymer multilayer aluminum capacitors to have excellent leveling properties, low volume resistivity, high conductivity and low ESR.

[0077] Compared with Example 6, the flow rate of the adhesive silver paste prepared by Comparative Example 1 using commercially available polydimethylsiloxane as a leveling agent was significantly reduced, the volume resistivity after curing was increased, and when the adhesive silver paste was used to prepare chip polymer multilayer aluminum capacitors, the ESR of the chip polymer multilayer aluminum capacitors was significantly increased, and the capacitor performance was reduced.

[0078] Compared with Example 6, Comparative Example 2 directly used unmodified hydroxyl organosiloxane oligomers as leveling agents, which reduced the flow rate and significantly increased the volume resistivity of the bonded silver paste film and the ESR of the capacitor.

[0079] Compared to Example 6, Comparative Example 3 used phosphate esters and hydroxyl organosiloxane oligomers as leveling agents instead of phosphate ester-modified hydroxyl organosiloxane oligomers. The resulting adhesive silver paste exhibited a lower flow rate, higher volume resistivity of the adhesive silver paste film, and a significantly higher ESR in the chip polymer multilayer aluminum capacitor. This demonstrates that simply using a mixture of phosphate esters and hydroxyl organosiloxane oligomers without a condensation reaction cannot achieve the effects of this invention.

[0080] In summary, the phosphate-modified polyorganosiloxane of the present invention can be used to prepare a capacitor bonding silver paste with excellent leveling properties and high conductivity (low ESR), which is very suitable for preparing high-performance MLPCs.

[0081] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0082] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A phosphate-modified polyorganosiloxane, characterized in that, Includes at least one of the compounds shown in structural formula I: Wherein, R1, R2, and R3 are independently selected from methyl, ethyl, and phenyl; R4 and R5 are independently selected from hydrogen, methyl, ethyl, butyl, glyceryl, 2-ethylhexyl, and isooctyl, and at least one of R4 and R5 is not hydrogen; a and b are integers and 2≤a≤20, 2≤b≤20.

2. The method for preparing phosphate-modified polyorganosiloxane as described in claim 1, characterized in that, Includes the following steps: (1) Dialkoxysilane and end-capping agent are taken as organosilicon monomers and co-hydrolysis condensation reaction is carried out in water and water-soluble organic solvent under the action of acid catalyst at 40℃~80℃. After the reaction is completed, the acid catalyst is removed, and then the organic layer is extracted and separated. The organic layer is washed with water until neutral and then distilled under reduced pressure to obtain hydroxy organosilicon oligomer solution. (2) The hydroxyl organosiloxane oligomer solution is mixed evenly with phosphate ester and condensation reaction is carried out at 70℃~100℃. The reaction product is distilled under reduced pressure to obtain the phosphate ester modified polyorganosiloxane.

3. The preparation method according to claim 2, characterized in that, The reaction time in step (1) is 3 to 5 hours; and / or, The temperature of vacuum distillation in step (1) is 80-100℃.

4. The preparation method according to claim 2, characterized in that, The reaction time in step (2) is 4 h to 10 h; and / or, The temperature for vacuum distillation in step (2) is 90℃~120℃.

5. The preparation method according to claim 2, characterized in that, The molar amount of the dialkoxysilane is 85% to 95% of the molar amount of the organosilicon monomer, and the molar amount of the capping agent is 5% to 15% of the molar amount of the organosilicon monomer; and / or, The mass of the water-soluble organic solvent is 0.3 to 0.9 times the mass of the organosilicon monomer; and / or, The number of moles of water is 1 to 3 times the number of moles of the hydrolyzable groups of the organosilicon monomer; and / or, The mass ratio of the acid catalyst to the water is (0.5:99.5) to (10:90); and / or, The mass of the phosphate ester is 10% to 15% of the mass of the hydroxyl organosiloxane oligomer solution.

6. The preparation method according to claim 2, characterized in that, The dialkoxysilane is a hydrocarbon dialkoxysilane, wherein the hydrocarbon dialkoxysilane is selected from at least one of methylphenyldimethoxysilane, diphenyldimethoxysilane, methylphenyldiethoxysilane, diphenyldiethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, and diethyldiethoxysilane; and / or, The end-capping agent is selected from at least one of hexamethyldisiloxane and hexamethyldisilazane; and / or, The phosphate ester is selected from at least one of monophosphate and diester, wherein the monophosphate includes monobutyl phosphate, 2-ethylhexyl phosphate, isooctyl phosphate, and glycerophosphate; the diester includes dimethyl phosphate, diethyl phosphate, and dibutyl phosphate; and / or, The water-soluble organic solvent is selected from at least one of methanol, ethanol, and isopropanol; and / or, The acid catalyst is selected from at least one of hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, trifluoromethanesulfonic acid, acetic acid, oxalic acid, p-toluenesulfonic acid, and acid clay; and / or, The extractant used in the extraction is selected from at least one of ethyl acetate, methyl acetate, ethyl propionate, toluene, and xylene.

7. The application of the phosphate-modified polyorganosiloxane as described in claim 1 or the phosphate-modified polyorganosiloxane prepared by any one of claims 2 to 6 in the preparation of adhesive silver paste for capacitors.

8. A bonding silver paste for capacitors, characterized in that, It is prepared from the following raw materials in parts by weight: 5-15 parts resin, 55-75 parts silver powder, 0.1-1.5 parts phosphate ester modified polyorganosiloxane as described in claim 1 or phosphate ester modified polyorganosiloxane prepared by any one of claims 2-6, and 10-30 parts solvent.

9. The adhesive silver paste for capacitors as described in claim 8, characterized in that, The resin is selected from at least one of acrylic resin, epoxy resin, vinyl chloride resin, polyurethane resin, and polyester resin; and / or The silver powder is selected from at least one of spherical silver with a particle size of 0.5 μm to 10 μm and flake silver with a particle size of 1 μm to 15 μm, and the surface of the silver powder is treated with oleic acid or stearic acid; and / or, The solvent is selected from two or more of butyl acetate, propylene glycol methyl ether acetate, ethylene glycol butyl ether, ethylene glycol butyl ether acetate, diethylene glycol ethyl ether acetate, and diethylene glycol butyl ether acetate.

10. A capacitor, characterized in that, The raw materials for manufacturing the capacitor include the bonding silver paste as described in claim 8 or 9.

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