A special-shaped ruthenium dioxide and its preparation method and resistor paste

Abstract

The present invention relates to a special-shaped ruthenium dioxide and a preparation method thereof and a resistor paste. The preparation steps of the special-shaped ruthenium dioxide of the present invention are: dissolving bismuth oxide in an acidic solution, adding ruthenate and a reducing solution to obtain a black precipitate; drying the black precipitate and then performing a heat treatment, washing it with an acidic solution after the heat treatment, and then washing it with water, and drying it to obtain the special-shaped ruthenium dioxide. In the process of preparing ruthenium dioxide by a reduction method, the present invention adds bismuth oxide. During the secondary heat treatment, bismuth oxide promotes the specialization of ruthenium dioxide, that is, when ruthenium dioxide is heat-treated, bismuth oxide makes the growth rate of different parts of the surface of ruthenium dioxide different, and forms a cone-thorn structure on the surface of ruthenium dioxide. Ruthenium dioxide of this shape has a larger specific surface area. When ruthenium dioxide of this shape is added to the resistor paste, the compactness of the conductive film can be ensured during the sintering process, the porosity can be reduced, the sintering stability of the resistor paste can be improved, and the resistor paste has excellent performance.

Description

Technical Field

[0001] The invention relates to the field of resistor paste preparation, and in particular to a special-shaped ruthenium dioxide and a preparation method thereof and a resistor paste. Background Art

[0002] Integrated circuits in modern electronic science and technology are the crystallization of scientific and technological achievements, mainly including: thick film hybrid integrated circuits, thin film hybrid integrated circuits and semiconductor integrated circuits. They have different advantages: in the application of digital circuits, semiconductor integrated circuits have absolute advantages, and their advantages such as high integration and low power consumption are suitable for mass production; in the application field of microwave and high-frequency circuits, thin film hybrid integrated circuits have obvious advantages: in the application of high temperature, high voltage, high current and high power circuits, thick film hybrid integrated circuits are irreplaceable. Thick film hybrid integrated circuits, usually referred to as thick film circuits or thick film hybrid circuits, are made by screen printing and sintering on substrates to produce interconnected wires, resistors, capacitors, inductors, etc. to meet the corresponding functional requirements of circuit units.

[0003] Among hybrid integrated circuits, thick film circuits have the advantages of small size, high power, flexible design, reliable performance, low cost and high cost performance. With the emergence and development of thick film electronic materials and thick film technology, thick film circuits have become an important part of integrated circuits. The basis of thick film circuits is thick film electronic materials, which include two parts: substrate and electronic paste. The substrate is the carrier of the thick film circuit, and the performance of the carrier material has an important influence on the quality of the thick film circuit. Thick film electronic paste is the core and key of the thick film circuit. The quality of the paste will directly affect the final performance of the prepared thick film components. The existing resistor paste has a high porosity of the sintered film, resulting in poor stability. It is urgent to develop a new resistor paste to improve its performance. Summary of the invention

[0004] The present invention aims to synthesize a special-shaped ruthenium dioxide powder. By adding the special-shaped ruthenium dioxide powder into a resistor paste, the sintering density of the paste can be improved, thereby improving the stability.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A method for preparing special-shaped ruthenium dioxide comprises the following steps:

[0007] S1. dissolving bismuth oxide in an acidic solution, adding ruthenate and a reducing solution to obtain a black precipitate;

[0008] S2. The black precipitate is dried and then heat-treated. After the heat treatment, it is washed with an acidic solution, then washed with water, and dried to obtain a special-shaped ruthenium dioxide.

[0009] Furthermore, in step S1, the mass fractions of each substance are:

[0010] 1 part of bismuth oxide, 5-10 parts of acidic solution, 2-5 parts of ruthenate, and 0.5-1 part of reducing solution.

[0011] Furthermore, the acidic solution includes hydrochloric acid and / or nitric acid, and the concentration of the acidic solution is 0.1-1 mol / L.

[0012] Furthermore, the ruthenate includes ruthenium trichloride and / or potassium ruthenate.

[0013] Furthermore, the reducing solution includes any one or more of formic acid, ethanol, oxalic acid, formate, hydrogen peroxide, and sodium borohydride, and the concentration of the reducing solution is 0.01-0.1 mol / L.

[0014] Furthermore, the temperature of the heat treatment is 500-800°C.

[0015] As a general inventive concept, the present invention also provides a special-shaped ruthenium dioxide prepared by the above-mentioned preparation method.

[0016] As a general inventive concept, the present invention also provides a resistor paste comprising the following components in percentage by mass:

[0017] Conductive phase 60-80%,

[0018] Glass powder 10-30%,

[0019] Organic carrier 10%-30%;

[0020] The conductive phase includes spherical ruthenium dioxide and irregular ruthenium dioxide, and the mass ratio of the spherical ruthenium dioxide to the irregular ruthenium dioxide is (4-19):1; the irregular ruthenium dioxide is prepared by the above-mentioned preparation method of irregular ruthenium dioxide.

[0021] Further, the glass powder is a mixture of B2O3, SiO2, Al2O3, ZnO and CaO. Preferably, the glass powder comprises 30wt% B2O3, 20wt% SiO2, 30wt% Al2O3, 10wt% ZnO and 10wt% CaO.

[0022] Further, the organic carrier is a mixture of terpineol, ethyl cellulose and alcohol resin dodecahydrate. Preferably, the organic carrier comprises 35wt% of terpineol, 12wt% of ethyl cellulose and 53wt% of alcohol resin dodecahydrate (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate).

[0023] Furthermore, the spherical ruthenium dioxide is prepared by the following method: calcining ruthenium hydroxide at 500-1000° C. to obtain spherical ruthenium dioxide powder.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] The present invention innovatively develops a special-shaped ruthenium dioxide. Bismuth oxide is added during the preparation of ruthenium dioxide by a reduction method. During the secondary heat treatment, bismuth oxide promotes the specialization of ruthenium dioxide. That is, during the heat treatment of ruthenium dioxide, bismuth oxide causes different growth rates at different locations on the surface of ruthenium dioxide, forming a cone-shaped structure on the surface of ruthenium dioxide. Ruthenium dioxide of this shape has a larger specific surface area. When ruthenium dioxide of this shape is added to a resistor paste, the density of the conductive film can be ensured during the sintering process, the porosity is reduced, the sintering stability of the resistor paste is improved, and the resistor paste has excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is an electron microscope image of the special-shaped ruthenium dioxide prepared in the present invention. DETAILED DESCRIPTION

[0027] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0028] Example 1

[0029] A method for preparing special-shaped ruthenium dioxide of the present invention comprises the following steps:

[0030] Dissolve 2.3 g of bismuth oxide in 12.6 g of 0.5 mol / L hydrochloric acid solution, add 8.1 g of ruthenium trichloride and 1.7 g of 0.01 mol / L ethanol solution to obtain a black precipitate;

[0031] The black precipitate is dried and then heat treated at 600° C. for 2 h. After the heat treatment, the bismuth oxide and bismuth chloride are washed with a hydrochloric acid solution to remove the bismuth oxide and the bismuth chloride. The precipitate is then washed with water to remove the hydrochloric acid. After drying, the shaped ruthenium dioxide powder of the present invention is obtained.

[0032] A resistor paste of the present invention comprises the following components in percentage by mass:

[0033] 60wt% conductive phase, 20wt% glass powder and 20wt% organic vehicle.

[0034] The conductive phase is prepared by mixing spherical ruthenium dioxide powder and the irregular ruthenium dioxide powder prepared in this embodiment in a mass ratio of 4:1, and the spherical ruthenium dioxide is obtained by directly calcining ruthenium hydroxide at a high temperature of 600° C. The diameter of the spherical ruthenium dioxide is 50-200nm, and the diameter of the irregular ruthenium dioxide is 300-400nm.

[0035] The glass powder consists of 30wt% B2O3, 20wt% SiO2, 30wt% Al2O3, 10wt% ZnO and 10wt% CaO; the organic carrier consists of 35wt% pine alcohol, 12wt% ethyl cellulose and 53wt% alcohol resin dodecahydrate.

[0036] Example 2

[0037] A method for preparing special-shaped ruthenium dioxide of the present invention comprises the following steps:

[0038] Dissolve 2.5 g of bismuth oxide in 23.4 g of 0.1 mol / L hydrochloric acid solution, add 6.5 g of ruthenium trichloride and 2.5 g of 0.01 mol / L oxalic acid solution to obtain a black precipitate;

[0039] The black precipitate is dried and then heat treated at 500° C. for 2 hours. After the heat treatment, the bismuth oxide and bismuth chloride are washed with a hydrochloric acid solution to remove the bismuth oxide and the bismuth chloride. The precipitate is then washed with water to remove the hydrochloric acid. After drying, the shaped ruthenium dioxide powder of the present invention is obtained.

[0040] A resistor paste of the present invention comprises the following components in percentage by mass:

[0041] 70wt% conductive phase, 15wt% glass powder and 15wt% organic vehicle.

[0042] The conductive phase is prepared by mixing spherical ruthenium dioxide powder and the irregular ruthenium dioxide powder prepared in this embodiment in a mass ratio of 12:1, and the spherical ruthenium dioxide is obtained by directly calcining ruthenium hydroxide at a high temperature of 800° C. The diameter of the spherical ruthenium dioxide is 50-200nm, and the diameter of the irregular ruthenium dioxide is 300-400nm.

[0043] The glass powder consists of 30wt% B2O3, 20wt% SiO2, 30wt% Al2O3, 10wt% ZnO and 10wt% CaO; the organic carrier consists of 35wt% pine alcohol, 12wt% ethyl cellulose and 53wt% alcohol resin dodecahydrate.

[0044] Example 3

[0045] A method for preparing special-shaped ruthenium dioxide of the present invention comprises the following steps:

[0046] Dissolve 2.2 g of bismuth oxide in 14.0 g of 1 mol / L hydrochloric acid solution, add 10.7 g of ruthenium trichloride and 1.2 g of 0.1 mol / L formic acid solution to obtain a black precipitate;

[0047] The black precipitate is dried and then heat treated at 700° C. for 2 hours. After the heat treatment, the bismuth oxide and bismuth chloride are washed with a hydrochloric acid solution to remove the bismuth oxide and the bismuth chloride. The precipitate is then washed with water to remove the hydrochloric acid. After drying, the shaped ruthenium dioxide powder of the present invention is obtained.

[0048] A resistor paste of the present invention comprises the following components in percentage by mass:

[0049] 65wt% conductive phase, 15wt% glass powder and 20wt% organic vehicle.

[0050] The conductive phase is prepared by mixing spherical ruthenium dioxide powder and the irregular ruthenium dioxide powder prepared in this embodiment at a mass ratio of 19:1, and the spherical ruthenium dioxide is obtained by directly calcining ruthenium hydroxide at a high temperature of 1000° C. The diameter of the spherical ruthenium dioxide is 50-200nm, and the diameter of the irregular ruthenium dioxide is 300-400nm.

[0051] The glass powder consists of 30wt% B2O3, 20wt% SiO2, 30wt% Al2O3, 10wt% ZnO and 10wt% CaO; the organic carrier consists of 35wt% pine alcohol, 12wt% ethyl cellulose and 53wt% alcohol resin dodecahydrate.

[0052] Example 4

[0053] A method for preparing special-shaped ruthenium dioxide of the present invention comprises the following steps:

[0054] Dissolve 2.3 g of bismuth oxide in 15.4 g of 0.3 mol / L hydrochloric acid solution, add 7.1 g of potassium ruthenate and 1.9 g of 0.1 mol / L formic acid solution to obtain a black precipitate;

[0055] The black precipitate is dried and then heat treated at 800° C. for 2 hours. After the heat treatment, the bismuth oxide and bismuth chloride are washed with a hydrochloric acid solution to remove the bismuth oxide and the bismuth chloride. The hydrochloric acid is then washed with water to remove the hydrochloric acid. After drying, the special-shaped ruthenium dioxide powder of the present invention is obtained.

[0056] A resistor paste of the present invention comprises the following components in percentage by mass:

[0057] 65wt% conductive phase, 20wt% glass powder and 15wt% organic vehicle.

[0058] The conductive phase is prepared by mixing spherical ruthenium dioxide powder and the irregular ruthenium dioxide powder prepared in this embodiment in a mass ratio of 8:1, and the spherical ruthenium dioxide is obtained by directly calcining ruthenium hydroxide at a high temperature of 500° C. The diameter of the spherical ruthenium dioxide is 50-200nm, and the diameter of the irregular ruthenium dioxide is 300-400nm.

[0059] The glass powder consists of 30wt% B2O3, 20wt% SiO2, 30wt% Al2O3, 10wt% ZnO and 10wt% CaO; the organic carrier consists of 35wt% pine alcohol, 12wt% ethyl cellulose and 53wt% alcohol resin dodecahydrate.

[0060] Comparative Example 1

[0061] A method for preparing ruthenium dioxide comprises the following steps:

[0062] Ruthenium hydroxide is directly calcined at a high temperature of 600°C to obtain spherical ruthenium dioxide powder.

[0063] Materials were weighed in a ratio of 60 wt % of spherical ruthenium dioxide powder, 20 wt % of glass powder, and 20 wt % of an organic carrier, and mixed using a three-roll mill to obtain a resistor paste.

[0064] The glass powder is composed of 30wt% B2O3, 20wt% SiO2, 30wt% Al2O3, 10wt% ZnO and 10wt% CaO; the organic carrier is composed of 35wt% pine alcohol, 12wt% ethyl cellulose and 53wt% alcohol resin.

[0065] The performance of the resistor pastes prepared in Example 1 and Comparative Example 1 was tested, and the results are shown in Table 1.

[0066] Table 1 Performance test results of the resistor pastes prepared in Example 1 and Comparative Example 1

[0067]

[0068]

[0069] Square resistance is tested according to GB / T 17473.3-2008;

[0070] ESD (electro-static+discharge) is electrostatic discharge, tested according to SJ20603-1996;

[0071] STOL (shot+time / term+overload) is a short-term overload and is tested in accordance with SJ20603-1996.

[0072] It can be seen from the test data in Table 1 that the resistor paste prepared by the method of the present invention has lower square resistance and good ESD and STOL performance, which proves that the special-shaped ruthenium dioxide prepared by the present invention can effectively improve the performance of the resistor paste.

Claims

1. A method for preparing special-shaped ruthenium dioxide, characterized in that: The steps include: S1. Dissolve bismuth oxide in an acidic solution, add ruthenate and a reducing solution to obtain a black precipitate; the mass fractions of each substance are: 1 part of bismuth oxide, 5-10 parts of acidic solution, 2-5 parts of ruthenate, and 0.5-1 part of reducing solution; S2. The black precipitate is dried and then heat-treated. After the heat treatment, it is washed with an acidic solution, then washed with water, and dried to obtain a special-shaped ruthenium dioxide; the heat treatment temperature is 500-800° C.; the diameter of the special-shaped ruthenium dioxide is 300-400 nm.

2. The method for preparing special-shaped ruthenium dioxide according to claim 1, characterized in that: The acidic solution includes hydrochloric acid and / or nitric acid, and the concentration of the acidic solution is 0.1-1 mol / L; the reducing solution includes any one or more of formic acid, ethanol, oxalic acid, formate, hydrogen peroxide, and sodium borohydride, and the concentration of the reducing solution is 0.01-0.1 mol / L; the ruthenate includes ruthenium trichloride and / or potassium ruthenate.

3. A special-shaped ruthenium dioxide, characterized in that: The heteromorphic ruthenium dioxide is prepared by the preparation method described in any one of claims 1-2.

4. A resistor paste, characterized in that: The following components are included in mass percentage: Conductive phase 60-80%, Glass powder 10-30%, Organic carrier 10%-30%; The conductive phase includes spherical ruthenium dioxide and irregular ruthenium dioxide, and the mass ratio of the spherical ruthenium dioxide to the irregular ruthenium dioxide is (4-19):1; the irregular ruthenium dioxide is prepared by the preparation method described in any one of claims 1-2.

5. The resistor paste according to claim 4, characterized in that: The glass powder includes B2O 3、 A mixture of SiO2, Al2O3, ZnO and CaO.

6. The resistor paste according to claim 4, characterized in that: The organic carrier is a mixture of terpineol, ethyl cellulose and alcohol resin dodecahydrate.

7. The resistor paste according to claim 4, characterized in that: The spherical ruthenium dioxide is prepared by the following method: calcining ruthenium hydroxide at 500-1000° C. to obtain spherical ruthenium dioxide powder.

8. The resistor paste according to claim 4, characterized in that: The diameter of the spherical ruthenium dioxide is 50-200nm.

Images