An electrode paste, a preparation method and a filter

Abstract

The present invention discloses an electrode paste, a preparation method and a filter, which relate to the technical field of electronic material and component processing, and solve the problems of poor adhesion tensile strength, uneven film thickness and poor strength after drying of the electrode paste. The electrode paste is used for a filter of ceramic medium and includes: a first carrier, a second carrier, a dispersant, a metal oxide, a glass powder and a silver conductive material, wherein the metal contained in the glass powder is the same as the metal contained in the metal oxide; the first carrier contains lauryl acetate, ethyl cellulose and rosin, the second carrier contains terpineol and hydrogenated castor oil, and the mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1). The paste is prepared by the preparation method of the paste. The present invention discloses an electrode paste, a preparation method and a filter for preparing an electrode paste of a filter of ceramic medium.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic materials and device processing, and particularly relates to an electrode paste, a preparation method and a filter. Background Art

[0002] A ceramic filter realizes the selection and control of signal frequency by printing a circuit on the ceramic surface and welding it to a circuit board. Since silver has advantages such as strong conductivity, a thermal expansion coefficient close to that of the porcelain blank, good thermal stability, and the ability to directly weld metals on the silver layer, the electrode paste containing silver is one of the key materials for filters. Its conductivity and the density of the conductive layer formed by the silver paste have an important impact on the performance of the filter.

[0003] The electrode paste for a samarium-calcium-aluminum ceramic system filter attaches the silver paste to the surface of the samarium-calcium-aluminum ceramic substrate by a spraying process, and through drying and sintering, a silver film conductive layer is covered on the surface layer of the porcelain body. However, at present, the performance of the electrode paste for the samarium-calcium-aluminum ceramic system filter still has defects such as a low Q value, poor adhesion tensile strength, uneven film thickness, and poor strength after drying. Summary of the Invention

[0004] The purpose of the present invention is to provide an electrode paste, a preparation method and a filter to ensure that the prepared electrode paste has the advantages of large adhesion tensile strength, uniform film thickness, and high strength after drying.

[0005] To achieve the above purpose, the present invention provides an electrode paste for a ceramic dielectric filter, comprising:

[0006] A first carrier, a second carrier, a dispersant, a metal oxide, a glass powder, and a silver conductive material, wherein the metal contained in the glass powder is the same as the metal contained in the metal oxide;

[0007] The first carrier comprises lauryl lactate, ethyl cellulose, and rosin, the second carrier comprises terpineol and hydrogenated castor oil, and the mass ratio of the first carrier to the second carrier is (10-15):(0.5-1).

[0008] Compared with the prior art, in the electrode paste provided by the present invention, the organic solvent contained in the first carrier is lauryl acetate, and the resins used are ethyl cellulose and rosin. Among them, the ethyl cellulose resin has good film-forming properties, and the formed film can maintain high strength and good toughness both at high temperature and low temperature. In addition, after the rosin resin is dissolved in lauryl acetate, it can provide high viscosity, tightly bond the first carrier, the second carrier and other raw materials, and provide sufficient adhesion strength and excellent long-term stability. The organic solvent contained in the second carrier is terpineol, and the thixotropic agent used is hydrogenated castor oil. Among them, hydrogenated castor oil can swell and gel in terpineol, and weak hydrogen bond binding occurs between the swollen particles due to the polar groups in the hydrogenated castor oil molecules, forming a thixotropic network structure, which can improve the suspension of the electrode paste formed in the subsequent steps and control the sagging of the paste without sacrificing fluidity and leveling property. Especially in the range where the mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1), under the combined action of the first carrier and the second carrier, the electrode paste formed in the subsequent steps has fluidity and is not prone to interface sagging. Therefore, when the electrode paste is applied to a ceramic filter, the film thickness is uniform, no peeling or blistering occurs, and the spraying effect is good. And due to the action of the rosin resin, sufficient adhesion strength and excellent long-term stability are provided for the formed electrode paste, so that the strength of the electrode paste after drying is significantly improved during the spraying, drying and other processes. Also, since the metals contained in the glass powder are the same as those contained in the metal oxides, it helps the sintering of the glass powder and the silver powder, improving the solderability and adhesion tensile force. In addition, the organic carrier obtained after swelling with the organic solvent is a jelly-like substance, and it has better mixing and dispersing properties with subsequent materials such as silver conductive materials, metal oxides, and glass powder, improving the spraying effect and the uniformity and flatness of the paste.

[0009] In the second aspect provided by the present invention, the present invention also provides a preparation method of an electrode paste, including: providing a first carrier and a second carrier;

[0010] Mixing a dispersant, a metal oxide, a glass powder, a silver powder, a diluent with the first carrier and the second carrier to obtain an electrode paste.

[0011] In the third aspect provided by the present invention, the present invention also provides a filter, including: a ceramic medium and an electrode formed on the ceramic medium, the material of the electrode being an electrode paste, and the material of the electrode being made by the preparation method of the electrode paste.

[0012] Compared with the prior art, a preparation method of an electrode paste and a filter provided by the present invention have the same beneficial effects as those in the first aspect, which will not be elaborated here. Description of the Drawings

[0013] The accompanying drawings described herein are used to provide a further understanding of the present invention and form a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0014] Figure 1 It shows the preparation flow chart of the electrode paste provided in this embodiment;

[0015] Figure 2(a) shows the first appearance electron microscope image of the electrode paste in Embodiment 1 of the present invention after sintering;

[0016] Figure 2(b) shows the second appearance electron microscope image of the electrode paste in Embodiment 1 of the present invention after sintering;

[0017] Figure 3(a) shows the first appearance electron microscope image of the electrode paste in Embodiment 2 of the present invention after sintering;

[0018] Figure 3(b) shows the second appearance electron microscope image of the electrode paste in Embodiment 2 of the present invention after sintering. Detailed Description of the Invention

[0019] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the following further describes the present invention in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined. The meaning of "several" is one or more unless otherwise specifically defined.

[0021] At the present stage, the electrode paste of the samarium-calcium-aluminum ceramic system filter still has defects such as low Q value, poor adhesion tension, uneven film thickness, and poor strength after drying.

[0022] To overcome this phenomenon, the embodiment of the present invention provides an electrode paste, which is used for the filter of ceramic medium and includes: a first carrier, a second carrier, a dispersant, a metal oxide, a glass powder and a silver conductive material, and the metal contained in the glass powder is the same as the metal contained in the metal oxide. Among them, the first carrier contains lauryl alcohol ester, ethyl cellulose and rosin, the second carrier contains terpineol and hydrogenated castor oil, and the mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1).

[0023] Exemplarily, the organic solvent contained in the first carrier is lauryl acetate, and the resins used are ethyl cellulose and rosin. Among them, ethyl cellulose resin has good film-forming properties, and the formed film can maintain high strength and good toughness both at high temperature and low temperature. In addition, after rosin resin is dissolved in lauryl acetate, it can provide high viscosity, tightly bond the first carrier, the second carrier and other raw materials together, providing sufficient adhesion strength and excellent long-term stability. The organic solvent contained in the second carrier is terpineol, and the thixotropic agent used is hydrogenated castor oil. Among them, hydrogenated castor oil can swell and gel in terpineol, and weak hydrogen bond binding occurs between the swollen particles due to the polar groups in the hydrogenated castor oil molecules, forming a thixotropic network structure, which can improve the suspension of the electrode paste formed in the subsequent steps and control the sagging of the paste without sacrificing fluidity and leveling properties. Especially in the range where the mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1), under the combined action of the first carrier and the second carrier, the electrode paste formed in the subsequent steps has fluidity and is not prone to interface sagging. Therefore, when this electrode paste is applied to a ceramic filter, the film thickness is uniform, there is no peeling or blistering phenomenon, and the spraying effect is good. And due to the action of rosin resin, sufficient adhesion strength and excellent long-term stability are provided for the formed electrode paste, making the strength of the electrode paste after drying significantly increased during spraying, drying and other processes. Also, since the metals contained in the glass powder are the same as those contained in the metal oxide, it helps the sintering of the glass powder and silver powder, improving solderability and adhesion tensile strength. In addition, the organic carrier obtained after swelling with the organic solvent is a jelly-like substance, which has better mixing and dispersing properties with subsequent silver conductive materials, metal oxides, glass powder and other materials, improving the spraying effect and the uniformity and flatness of the paste.

[0024] Exemplarily, by mass parts, in the first carrier, the mass part of lauryl acetate is 215 - 220 parts, the mass part of ethyl cellulose is 45 - 50 parts, and the mass part of rosin is 30 - 35 parts; in the second carrier, the mass part of terpineol is 70 - 75 parts, and the mass part of hydrogenated castor oil is 25 - 30 parts. The first carrier and the second carrier prepared within the above mass part range have significantly increased strength after drying, which can reach 4B as measured by experiments, and enable the resin to fully expand in the organic system, forming layer-by-layer coating. Under the influence of an appropriate amount of thixotropic agent, the electrode paste has fluidity and is not prone to interface sagging, and has excellent spraying effect and uniform thickness without peeling.

[0025] In an alternative embodiment, the mass fraction of the dispersant used in the embodiments of the present invention is 0.1 part to 1 part, the mass fraction of the metal oxide is 0.2 part to 1 part, the mass fraction of the glass powder is 0.5 part to 1.5 parts, the mass fraction of the silver conductive material is 75 parts to 80 parts, the mass fraction of the first carrier is 10 to 15 parts, and the mass fraction of the second carrier is 0.5 to 1 part.

[0026] Exemplarily, the metal oxide is at least one of bismuth oxide and cuprous oxide, and the glass powder is a Bi-Cu-Sm system glass powder. Among them, for the Bi-Cu-Sm system glass powder, the glass powder contains at least bismuth oxide, cuprous oxide and samarium oxide, and may also contain one or more of lithium oxide, sodium oxide, potassium oxide, magnesium oxide, calcium oxide, strontium oxide, barium oxide, phosphorus oxide, titanium oxide and nickel oxide. During the sintering process, the organic resin and organic solvent volatilize and decompose, and the Bi-Cu-Sm system glass powder melts into a film to form a firm and conductive coating with the silver conductive material. However, when the glass powder is used alone in the reaction, the adhesion of the prepared electrode paste does not meet the tensile requirements. Therefore, a metal oxide is needed to react with the glass powder. It has been experimentally measured that especially when bismuth oxide and cuprous oxide are used in combination with the bismuth copper samarium system glass for sintering, the adhesion of the prepared electrode paste can be significantly improved.

[0027] Exemplarily, the dispersant used in the embodiments of the present invention is a cationic surfactant, which can improve the storage stability of the prepared electrode paste. The cationic surfactant is at least one of dodecyl trimethyl ammonium bromide and dodecyl dimethyl benzyl ammonium chloride. A diluent may also be used in the embodiments of the present invention. The mass fraction of the diluent is 10 parts to 14 parts, and the diluent is at least one of acetone, ethanol and ethylene glycol monoethyl ether.

[0028] Exemplarily, the silver conductive material includes at least two different forms of silver conductive materials; when the form of the silver conductive material is spherical, the average particle size of the spherical silver conductive material is 1.5 μm - 2 μm; when the form of the silver conductive material is flaky, the average particle size of the flaky silver conductive material is 3.5 μm - 4.5 μm.

[0029] Exemplarily, the silver conductive material is the main component of the electrode paste, and its content in the electrode paste is directly related to the conductivity. When the mass fraction of the silver conductive material is 75 parts to 80 parts, it is beneficial to improve its conductivity. In practical applications, when the mass fraction of the silver conductive material exceeds 80 parts, its conductivity cannot be improved, and the probability of being coated by the resin is low. After curing into a film, the adhesion of the silver conductor decreases, and there is a risk of silver conductive material falling off. When the mass fraction of the silver conductive material is less than 60 parts, the change of resistance is unstable. Moreover, the average particle size of the silver conductive material is also related to the conductivity of the electrode paste. Under the same volume, the smaller the average particle size of the silver conductive material, the higher the contact probability between the silver conductive materials, and the conductivity is improved. And the remaining space is smaller, thus avoiding the phenomenon that the larger space left due to the larger average particle size of the silver conductive material is blocked by resins such as non-conductive ethyl cellulose and rosin, thereby avoiding the decrease in conductivity. Therefore, when selecting spherical silver conductive materials with an average particle size of 1.5 μm - 2 μm, the conductivity of the prepared electrode paste is relatively high. Similarly, when selecting flake silver conductive materials with an average particle size of 3.5 μm - 4.5 μm, the conductivity of the prepared electrode paste is relatively high.

[0030] Figure 1 The flowchart of the preparation of the electrode paste provided in this embodiment is shown. As Figure 1 shown, the preparation method of the electrode paste provided by the present invention includes:

[0031] Step 101: Provide a first carrier and a second carrier.

[0032] Exemplarily, 215 parts to 220 parts by mass of the organic solvent alcohol ester twelve is placed in a container, and the container is placed in a water bath at 75°C to 90°C for preheating. Weigh 45 parts to 50 parts by mass of ethyl cellulose and 30 parts to 35 parts by mass of rosin, add the above raw materials to the preheated alcohol ester twelve, and disperse for 2 hours at a rotation speed of 900 r / min to 2000 r / min to prepare the first carrier. 70 parts to 75 parts by mass of terpineol is placed in a container, and the container is placed in a water bath at 75°C to 90°C for preheating. Weigh 25 parts to 30 parts by mass of hydrogenated castor oil, add it to the preheated terpineol, and disperse for 2 hours at a rotation speed of 900 r / min to 2000 r / min to prepare the second carrier. Among them, if the hydrogenated castor oil is added to terpineol above 90°C and the dispersion time is less than or equal to 30 min to 40 min, the hydrogenated castor oil will not form a thixotropic gel network but will precipitate "crystals".

[0033] Step 102: Mix the dispersant, metal oxide, glass powder, silver conductive material, diluent with the first carrier and the second carrier to obtain the electrode paste.

[0034] Exemplarily, 0.1 to 1 part by mass of a dispersant, 0.2 to 1 part by mass of a metal oxide, 0.5 to 1.5 parts by mass of glass powder, 75 to 80 parts by mass of a silver conductive material, 10 to 15 parts by mass of a prepared first carrier, and 0.5 to 1 part by mass of a second carrier are added to a container and mixed. Then, a homogenizer is used to fully disperse the materials in the container. After uniform dispersion, rolling is performed by a three-roll mill to make the fineness reach below 7. At this time, 10 to 14 parts by mass of a diluent can be added to make the slurry meet the spraying requirements.

[0035] An embodiment of the present invention further provides a filter, which includes a ceramic dielectric and an electrode formed on the ceramic dielectric. The material of the electrode is an electrode paste and is made by the preparation method of the electrode paste.

[0036] In order to verify the effect of the electrode paste provided by the embodiment of the present invention, the embodiment of the present invention is proved by comparing the example with the comparative example.

[0037] Example 1

[0038] An embodiment of the present invention provides an electrode paste for a filter of a ceramic dielectric, including: a first carrier, a second carrier, a dispersant, a metal oxide, glass powder, and a silver conductive material. The metal contained in the glass powder is the same as the metal contained in the metal oxide. The first carrier includes dodecyl acetate, ethyl cellulose, and rosin. The second carrier includes terpineol and hydrogenated castor oil. The mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1). A total of 2 SEM images of the electrode paste after sintering are taken. Fig. 2(a) shows the first SEM image of the electrode paste of Example 1 of the present invention after sintering;

[0039] Fig. 2(b) shows the second SEM image of the electrode paste of Example 1 of the present invention after sintering. It can be seen from Fig. 2(a) and Fig. 2(b) that after sintering, the surface of the electrode paste of Example 1 of the present invention is uniform and has small pores.

[0040] The preparation method of the electrode paste provided by the embodiment of the present invention includes the following steps:

[0041] Step 1: Prepare the first carrier and the second carrier: Place 219.6 g of lauryl alcohol ester in a container, and place the container in a water bath at 75 °C for preheating. Weigh 49.4 g of ethyl cellulose and 31 g of rosin, add the above raw materials to the preheated lauryl alcohol ester, and disperse at a rotation speed of 900 r / min for 2 hours to prepare the first carrier. Place 75 g of terpineol in a container, and place the container in a water bath at 90 °C for preheating. Weigh 25 g of hydrogenated castor oil and add it to the preheated terpineol, and disperse at a rotation speed of 2000 r / min for 2 hours to prepare the second carrier.

[0042] Step 2: Prepare the electrode paste: Add 0.6 g of dodecyl trimethyl ammonium bromide, 0.3 g of bismuth oxide, 0.2 g of cuprous oxide, 0.7 g of bismuth-copper-samarium system glass, 75 g of spherical silver conductive material with an average particle size of 1.5 - 2 μm, 12 g of the prepared first carrier, and 0.5 g of the prepared second carrier into a container; use a homogenizer to fully disperse the materials in the container, and after uniform dispersion, roll through a three-roll mill to make the fineness reach below 7. Add 10 ml of acetone (analytical pure) to make the paste meet the spraying requirements. The performance test of this electrode paste is shown in Table 1.

[0043] Example 2

[0044] The electrode paste provided by the embodiment of the present invention is used for a filter of ceramic medium, and includes: a first carrier, a second carrier, a dispersant, a metal oxide, a glass powder, and a silver conductive material, and the metals contained in the glass powder are the same as those contained in the metal oxide. The first carrier contains lauryl alcohol ester, ethyl cellulose, and rosin, the second carrier contains terpineol and hydrogenated castor oil, and the mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1). The SEM images of the electrode paste after sintering were taken 2 times in total. Fig. 3(a) shows the first SEM image of the electrode paste of Example 2 of the present invention after sintering;

[0045] Fig. 3(b) shows the second SEM image of the electrode paste of Example 2 of the present invention after sintering. It can be seen from Fig. 3(a) and Fig. 3(b) that after sintering, the surface of the electrode paste of Example 2 of the present invention is uniform and has smaller pores.

[0046] The preparation method of the electrode paste provided by the embodiment of the present invention includes the following steps:

[0047] Step 1: Prepare the first carrier and the second carrier: Place 216 g of lauryl alcohol phthalate in a container, and place the container in a water bath at 80 °C for preheating. Weigh 46 g of ethyl cellulose and 30 g of rosin, add the above raw materials to the preheated lauryl alcohol phthalate, and disperse at a rotation speed of 900 r / min for 2 hours to prepare the first carrier. Place 70 g of terpineol in a container, and place the container in a water bath at 90 °C for preheating. Weigh 30 g of hydrogenated castor oil, add it to the preheated terpineol, and disperse at a rotation speed of 2000 r / min for 2 hours to prepare the second carrier.

[0048] Step 2: Prepare the electrode paste: Add 0.5 g of dodecyl dimethyl benzyl ammonium chloride, 0.5 g of bismuth oxide, 0.5 g of cuprous oxide, 1.5 g of bismuth-copper-samarium system glass, 75 g of spherical silver conductive material with an average particle size of 1.5 - 2 μm, 11 g of the prepared first carrier, and 1.0 g of the prepared second carrier into a container; use a homogenizer to fully disperse the materials in the container, and after uniform dispersion, roll through a three-roll mill to make the fineness reach below 7. Add 11 ml of ethanol (analytical pure) to make the paste meet the spraying requirements. The performance test results of this electrode paste are shown in Table 1.

[0049] Example 3

[0050] The electrode paste provided by the embodiment of the present invention is used for a filter of ceramic medium, and includes: a first carrier, a second carrier, a dispersant, metal oxides, glass powder, and silver conductive material, and the metals contained in the glass powder are the same as those contained in the metal oxides. The first carrier contains lauryl alcohol phthalate, ethyl cellulose, and rosin, the second carrier contains terpineol and hydrogenated castor oil, and the mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1).

[0051] The preparation method of the electrode paste provided by the embodiment of the present invention includes the following steps:

[0052] Step 1: Prepare the first carrier and the second carrier: Place 215 g of lauryl alcohol phthalate in a container, and place the container in a water bath at 85 °C for preheating. Weigh 50 g of ethyl cellulose and 35 g of rosin, add the above raw materials to the preheated lauryl alcohol phthalate, and disperse at a rotation speed of 1000 r / min for 2 hours to prepare the first carrier. Place 74 g of terpineol in a container, and place the container in a water bath at 90 °C for preheating. Weigh 26 g of hydrogenated castor oil, add it to the preheated terpineol, and disperse at a rotation speed of 1500 r / min for 2 hours to prepare the second carrier.

[0053] Step 2: Prepare the electrode paste: Add 1.0 g of dodecyldimethylbenzylammonium chloride, 0.1 g of bismuth oxide, 0.1 g of cuprous oxide, 0.8 g of bismuth-copper-samarium system glass, 75 g of flake-shaped silver conductive material with an average particle size of 3.5 μm - 4.5 μm, 10.5 g of the prepared first carrier, and 0.5 g of the prepared second carrier into a container; use a homogenizer to fully disperse the materials in the container, and after uniform dispersion, roll through a three-roll mill to make the fineness reach below 7. Add 12 ml of ethylene glycol monoethyl ether (analytical pure) to make the paste meet the spraying requirements. The performance test results of this electrode paste are shown in Table 1.

[0054] Example 4

[0055] An electrode paste provided by an embodiment of the present invention is used for a filter of a ceramic dielectric, and includes: a first carrier, a second carrier, a dispersant, a metal oxide, a glass powder, and a silver conductive material, and the metals contained in the glass powder are the same as those contained in the metal oxide. The first carrier contains lauryl acetate, ethyl cellulose, and rosin, the second carrier contains terpineol and hydrogenated castor oil, and the mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1).

[0056] The preparation method of the electrode paste provided by an embodiment of the present invention includes the following steps:

[0057] Step 1: Prepare the first carrier and the second carrier: Place 215 g of lauryl acetate in a container, and place the container in a water bath at 80°C for preheating. Weigh 50 g of ethyl cellulose and 35 g of rosin, add the above raw materials into the preheated lauryl acetate, and disperse at a rotation speed of 1000 r / min for 2 hours to prepare the first carrier. Place 74 g of terpineol in a container, and place the container in a water bath at 90°C for preheating. Weigh 26 g of hydrogenated castor oil, add it into the preheated terpineol, and disperse at a rotation speed of 1500 r / min for 2 hours to prepare the second carrier.

[0058] Step 2: Prepare the electrode paste: Add 0.1 g of dodecyldimethylbenzylammonium chloride, 0.1 g of bismuth oxide, 0.1 g of cuprous oxide, 0.8 g of bismuth-copper-samarium system glass, 55 g of spherical silver conductive material with an average particle size of 1.5 - 2 μm, 20 g of flake-shaped silver conductive material with an average particle size of 3.5 μm - 4.5 μm, 11.4 g of the prepared first carrier, and 0.5 g of the prepared second carrier into a container; use a homogenizer to fully disperse the materials in the container, and after uniform dispersion, roll through a three-roll mill to make the fineness reach below 7. Add 12 ml of ethylene glycol monoethyl ether (analytical pure) to make the paste meet the spraying requirements. The performance test results of this electrode paste are shown in Table 1.

[0059] Comparative Example 1

[0060] The comparative example of the present invention provides an electrode paste for a ceramic dielectric filter, comprising: a first carrier, a second carrier, a dispersant, a glass powder, and a silver conductive material. The first carrier contains lauryl acetate, ethyl cellulose, and rosin, the second carrier contains terpineol and hydrogenated castor oil, and the mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1).

[0061] The preparation method of the electrode paste provided by the comparative example of the present invention includes the following steps:

[0062] First step, prepare the first carrier and the second carrier: Place 215 g of lauryl acetate in a container, and place the container in a water bath at 80 °C for preheating. Weigh 50 g of ethyl cellulose and 35 g of rosin, add the above raw materials to the preheated lauryl acetate, and disperse for 2 hours at a rotation speed of 1000 r / min to prepare the first carrier. Place 74 g of terpineol in a container, and place the container in a water bath at 90 °C for preheating. Weigh 26 g of hydrogenated castor oil, add it to the preheated terpineol, and disperse for 2 hours at a rotation speed of 1500 r / min to prepare the second carrier.

[0063] Second step, prepare the electrode paste: Add 0.1 g of dodecyl dimethyl benzyl ammonium chloride, 1.0 g of bismuth copper samarium system glass, 55 g of spherical silver conductive material with an average particle size of 1.5 - 2 μm, 20 g of flake silver conductive material with an average particle size of 3.5 μm - 4.5 μm, 11.4 g of the prepared first carrier, and 0.5 g of the prepared second carrier into a container; use a homogenizer to fully disperse the materials in the container, and after uniform dispersion, roll through a three-roll mill to make the fineness reach below 7. Add 12 ml of ethylene glycol monoethyl ether (analytical pure) to make the paste meet the spraying requirements. The performance test results of this electrode paste are shown in Table 1.

[0064] Comparative Example 2

[0065] The comparative example of the present invention provides an electrode paste for a ceramic dielectric filter, comprising: a first carrier, a dispersant, a glass powder, and a silver conductive material. The first carrier contains lauryl acetate, ethyl cellulose, and rosin.

[0066] The preparation method of the electrode paste provided by the comparative example of the present invention includes the following steps:

[0067] First step, prepare the first carrier: Place 215 g of lauryl acetate in a container, and place the container in a water bath at 80 °C for preheating. Weigh 50 g of ethyl cellulose and 35 g of rosin, add the above raw materials to the preheated lauryl acetate, and disperse for 2 hours at a rotation speed of 1000 r / min to prepare the first carrier.

[0068] Step 2: Prepare the electrode paste: Add 0.1 g of dodecyldimethylbenzylammonium chloride, 1.0 g of bismuth-copper-samarium system glass, 55 g of spherical silver conductive material with an average particle size of 1.5 - 2 μm, 20 g of flake-shaped silver conductive material with an average particle size of 3.5 μm - 4.5 μm, 11.4 g of the prepared first carrier, and 0.5 g of the prepared second carrier into a container; use a homogenizer to fully disperse the materials in the container, and after uniform dispersion, roll them through a three-roll mill to make the fineness reach below 7. Add 12 ml of ethylene glycol monoethyl ether (analytical pure) to make the paste meet the spraying requirements. The performance test results of this electrode paste are shown in Table 1.

[0069] Table 1 Performance test results of the electrode pastes of Examples 1 - 4 and Comparative Examples 1 - 2

[0070]

[0071] As can be seen from Table 1, by testing the adhesion of the electrode pastes of Examples 1 - 4 and Comparative Examples 1 - 2 twice, it shows that the adhesion of the electrode pastes prepared in Examples 1 - 4 is relatively large, and the test results are not accidental. While the adhesion of the electrode pastes prepared in Comparative Examples 1 and 2 is relatively small. During the adhesion test, when the value is 29.8 N / mm 2 ~36.2 N / mm 2 the solder joints fall off and no porcelain body is detached, indicating that when using metal oxides (such as bismuth oxide and cuprous oxide) in combination with glass powder, the adhesion of the prepared electrode paste is significantly improved. Moreover, as can be seen from Table 1, the Q values of Examples 1 - 4 of the present invention are much larger than those of Comparative Examples 1 - 2. In addition, Figures 2(a), 2(b), 3(a), and 3(b) of the examples of the present invention prove that when adding the first carrier containing lauryl alcohol ester, ethyl cellulose, and rosin and the second carrier containing terpineol and hydrogenated castor oil to the raw materials, under the combined action of the two carriers, the film thickness of the sintered electrode paste is uniform, no peeling or foaming phenomenon occurs, and the spraying effect is good. Secondly, among Examples 1 - 4 and Comparative Examples 1 - 2, Examples 1 - 4 and Comparative Example 1 that use the first carrier and the second carrier have higher drying strength, while Comparative Example 2 that does not use the second carrier has a drying strength much lower than that of Examples 1 - 4 and Comparative Example 1.

[0072] The above are only specific embodiments of the present invention. Obviously, various modifications and combinations can be made without departing from the spirit and scope of the present invention. Accordingly, this specification and the accompanying drawings are merely exemplary illustrations of the present invention defined by the appended claims, and are considered to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the intention of the present invention includes these changes and modifications. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the said claims.

Claims

1. An electrode paste, characterized in that, Filter for ceramic medium, wherein the electrode paste comprises: a first carrier, a second carrier, a dispersant, a metal oxide, a glass powder, and a silver conductive material; the metal oxide is at least one of bismuth oxide and cuprous oxide, and the glass powder is a Bi-Cu-Sm system glass powder; The first carrier contains lauryl acetate, ethyl cellulose, and rosin, and the second carrier contains terpineol and hydrogenated castor oil. The mass ratio of the first carrier to the second carrier is (10 - 15):(0.5 - 1); by mass fraction, in the first carrier, the mass fraction of lauryl acetate is 215 - 220 parts, the mass fraction of ethyl cellulose is 45 - 50 parts, and the mass fraction of rosin is 30 - 35 parts; in the second carrier, the mass fraction of terpineol is 70 - 75 parts, and the mass fraction of hydrogenated castor oil is 25 - 30 parts; the mass fraction of the dispersant is 0.1 - 1 part, the mass fraction of the metal oxide is 0.2 - 1 part, the mass fraction of the glass powder is 0.5 - 1.5 parts, the mass fraction of the silver conductive material is 75 - 80 parts, the mass fraction of the first carrier is 10 - 15 parts, and the mass fraction of the second carrier is 0.5 - 1 part; the silver conductive material includes at least two different forms of silver conductive materials; when the form of the silver conductive material is spherical, the average particle size of the spherical silver conductive material is 1.5 μm - 2 μm; when the form of the silver conductive material is flaky, the average particle size of the flaky silver conductive material is 3.5 μm - 4.5 μm.

2. The electrode paste according to claim 1, characterized in that, The dispersant is a cationic surfactant, and the cationic surfactant is at least one of dodecyl trimethyl ammonium bromide and dodecyl dimethyl benzyl ammonium chloride.

3. The preparation method of the electrode paste according to claim 1 or 2, characterized in that, Comprising: Providing a first carrier and a second carrier; Mixing the dispersant, the metal oxide, the glass powder, the silver conductive material, and a diluent with the first carrier and the second carrier to obtain an electrode paste.

4. The preparation method of the electrode paste according to claim 3, characterized in that, The providing the first carrier and the second carrier includes: Subjecting lauryl acetate to water bath heating, mixing ethyl cellulose and rosin with the heated lauryl acetate and then stirring to obtain the first carrier; Subjecting terpineol to water bath heating, mixing hydrogenated castor oil with the heated terpineol and then stirring to obtain the second carrier.

5. The preparation method of the electrode paste according to claim 4, characterized in that, The heating temperature is 75°C - 90°C; the stirring speed is 900 r / min - 2000 r / min.

6. A filter, characterized in that, Comprising a ceramic medium and an electrode formed on the ceramic medium, wherein the material of the electrode is the electrode paste according to claim 1 or 2, and the material of the electrode is prepared by the preparation method of the electrode paste according to any one of claims 3 - 5.

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