High-stability resistance paste and preparation method thereof

Abstract

The application discloses a high-stability resistance paste and a preparation method thereof, and relates to the technical field of resistance paste, and comprises the following raw materials in parts by weight: 65-75 parts of a conductive phase, 30-35 parts of an organic carrier, 15-20 parts of a glass bonding phase and 2.5-3.5 parts of modified aluminum nitride. The modified aluminum nitride used in the application enhances the bonding strength of the glass bonding phase, avoids the decrease of the stability of the resistance paste conductor phase, and improves the resistance value stability of the resistance paste after multiple sintering.

Description

Technical Field

[0001] This invention relates to the field of resistive paste technology, specifically to a highly stable resistive paste and its preparation method. Background Technology

[0002] Resistive paste is a functional paste composed of a conductive phase (such as metals or metal oxides like silver, ruthenium, and palladium), a glass binder phase (low-melting-point glass powder), inorganic additives (oxides, nitrides), and an organic carrier (resin, solvent, etc.). Resistive paste is used to form resistive films through processes such as screen printing and sintering, and is widely used in the manufacture of electronic components.

[0003] Previous studies have used aluminum nitride powder as a thermally conductive component to reduce heat accumulation in the slurry, thereby lowering its temperature and extending the lifespan of the heating device. However, the significant difference in thermal expansion coefficients between aluminum nitride powder and the glass binder phase leads to residual stress after high-temperature sintering and cooling. This stress weakens the bond strength between the aluminum nitride and the glass phase, potentially causing microcracks or delamination, resulting in a drift in the resistive film's resistance value. The resistance value changes considerably after multiple sintering cycles. Furthermore, contact between aluminum nitride and lead oxide present or residual in the glass binder phase forms low-melting-point lead aluminate, which reduces the stability of the conductor phase in the resistive slurry.

[0004] Therefore, it is necessary to develop new modification methods to solve the problem of large changes in resistance value after multiple sintering caused by the mismatch of thermal expansion coefficients, and to avoid aluminum nitride and lead oxide from coming into contact, which would reduce the stability of the resistance paste, thereby obtaining a resistance paste with higher stability. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a highly stable resistive slurry and its preparation method.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A highly stable resistive paste comprises the following raw materials in parts by weight: 65-75 parts of conductive phase, 30-35 parts of organic carrier, 15-20 parts of glass binder phase, and 2.5-3.5 parts of modified aluminum nitride;

[0008] Furthermore, the conductive phase is obtained by mixing ruthenium dioxide and bismuth ruthenate in a mass ratio of 2-3:1; the glass binder phase is low-melting-point glass powder;

[0009] Furthermore, the organic carrier comprises 30-40 parts of resin, 40-45 parts of solvent, and 15-20 parts of additives;

[0010] Furthermore, the resin is selected from one of silicone resin, rosin resin, methylcellulose, ethylcellulose, and hydroxycellulose;

[0011] Furthermore, the solvent is selected from one of terpineol, N-methylpyrrolidone, butyl carbitol, and diethylene glycol ethyl ether;

[0012] Furthermore, the additive is oleic acid or polyethylene wax;

[0013] The high-stability resistive slurry is prepared by the following steps:

[0014] The resin, solvent, and additives are stirred and mixed at 65-75℃ for 35-40 minutes, and then cooled to room temperature to obtain an organic carrier. The conductive phase, organic carrier, glass binder phase, and modified aluminum nitride are mixed and stirred at 600-800 rpm for 30-40 minutes, and then ground to obtain a high-stability resistive slurry.

[0015] Furthermore, the fineness of the high-stability resistive slurry is 3-5 μm;

[0016] The modified aluminum nitride is prepared by the following steps:

[0017] Step M1: Mix aluminum source, anhydrous ethanol, isopropanol, and deionized water, stir and adjust pH, add pretreated aluminum nitride powder, disperse ultrasonically, heat and stir, let stand for aging, dry and grind into powder, and perform high-temperature treatment in a protective gas atmosphere to obtain product m1.

[0018] Step M2: Mix product m1 with anhydrous ethanol, disperse by ultrasonication, add hydrolysate, heat and stir to obtain product m2; mix unsaturated fatty acids and acetone, adjust pH, add pretreated tin dioxide, heat and ultrasonically vibrate, wash with n-hexane, and vacuum dry to obtain product m3.

[0019] Step M3: After ultrasonically dispersing product m3, DMF, and anhydrous ethanol, add m-chloroperoxybenzoic acid, heat and stir to obtain product m4; after ultrasonically dispersing product m2, product m4, DMAc, and methanol, add tetrabutylammonium chloride and pyridine, heat and stir to obtain product m5.

[0020] Step M4: After ultrasonically dispersing nano-zirconia and anhydrous ethanol, add halosilane hydrolysate, heat and stir to obtain product m6; after ultrasonically dispersing product m5, product m6, DMSO and methanol, add potassium hydroxide ethanol solution and tetrabutylammonium bromide, heat and reflux and stir to obtain modified aluminum nitride.

[0021] The preparation of the modified aluminum nitride includes the following specific steps:

[0022] Step M1: Mix aluminum source, anhydrous ethanol, isopropanol, and deionized water, stir and adjust pH to 4.8-5.2, add pretreated aluminum nitride powder, ultrasonically disperse for 30-40 min, heat to 60-65℃, stir for 4-4.5 h, let stand for aging for 24-24.5 h, dry at 90-100℃ for 24-25 h, grind into powder, and perform high-temperature treatment in a protective gas atmosphere to obtain product m1;

[0023] Furthermore, the ratio of aluminum source, anhydrous ethanol, isopropanol, deionized water, and pretreated aluminum nitride powder is 1-1.5g: 5-10mL: 3-5mL: 0.5-1mL: 0.5-1g; the aluminum source is aluminum isopropoxide or aluminum nitrate; the pretreated aluminum nitride powder is obtained by ball milling aluminum nitride and citric acid at a mass ratio of 9-10:1 for 11-12 hours and drying at 100-110℃; the high-temperature treatment process involves heating to 430-450℃ at 5-7℃ / min, holding for 1-1.5 hours, and then heating to 700-750℃ at 5-7℃ / min and holding for 1-1.5 hours.

[0024] In step M1, aluminum oxide coated with aluminum nitride is prepared by sol-gel method to obtain product m1;

[0025] Step M2: Mix product m1 with anhydrous ethanol, sonicate for 35-40 min, add hydrolysate, and stir at 50-55℃ for 3-3.5 h to obtain product m2; mix unsaturated fatty acids and acetone and stir for 5-10 min, adjust pH to 5-5.5, add pretreated tin dioxide, sonicate at 48-52℃ for 8-8.5 h, wash with n-hexane, and then vacuum dry at 50-55℃ for 4-4.5 h to obtain product m3;

[0026] Further, the ratio of product m1, anhydrous ethanol, and hydrolysate is 5-6 g: 30-35 mL: 10-12 mL; the hydrolysate is a mixture of an aminosilane coupling agent and a mixed solvent at a ratio of 11.5-12 g: 25-30 mL, stirred at 45-50 °C for 1-1.2 h, and then cooled to obtain the final product; the aminosilane coupling agent is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane; the mixed solvent is ethanol and water at a volume ratio of 8-9:1. The mixture was prepared with 95% ethanol by volume; the ratio of unsaturated fatty acid, acetone, and pretreated tin dioxide was 1-1.2g:25-30mL:5-6g; the unsaturated fatty acid was undecenoic acid; the pretreated tin dioxide was prepared by soaking tin dioxide in sodium hydroxide solution and ultrasonically vibrating for 6-6.5h, washing until neutral, and then drying at 105-110℃ for 2-2.5h; the concentration of the sodium hydroxide solution was 2-2.5mol / L.

[0027] In step M2, the silanol formed by the hydrolysis of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane modifies the surface of product m1 to obtain product m2 with amino groups on the surface; the unsaturated fatty acid modifies the surface of tin dioxide to obtain product m3 with alkenyl groups.

[0028] Step M3: Mix product m3, DMF, and anhydrous ethanol and ultrasonically disperse for 40-45 min. Add m-chloroperoxybenzoic acid and stir at 55-60℃ for 7-7.5 h to obtain product m4. Mix product m2, product m4, DMAc, and methanol and ultrasonically disperse for 1-1.2 h. Add tetrabutylammonium chloride and pyridine and stir at 40-50℃ for 4.5-5.5 h to obtain product m5.

[0029] Furthermore, the ratio of product m3, DMF, anhydrous ethanol, and m-chloroperoxybenzoic acid is 8-8.5g: 35-40mL: 10-15mL: 2.5-3g; the ratio of product m2, product m4, DMAc, methanol, tetrabutylammonium chloride, and pyridine is 7-8g: 9-10g: 75-80mL: 5-10mL: 0.5-0.7g: 0.1-0.3g.

[0030] During step M3, the alkenyl group of product m3 is oxidized to an epoxy group to obtain product m4; the amino group of product m2 reacts with the epoxy group of product m4 to generate a grafted product containing hydroxyl groups, namely aluminum oxide coated with aluminum nitride and tin dioxide, i.e. product m5.

[0031] Step M4: Mix and ultrasonically disperse nano-zirconia and anhydrous ethanol for 35-40 min, add halosilane hydrolysate, and stir at 58-62℃ for 2-2.5 h to obtain product m6; mix and ultrasonically disperse product m5, product m6, DMSO, and methanol for 50-55 min, add potassium hydroxide ethanol solution and tetrabutylammonium bromide, heat to 100-110℃, and reflux and stir for 9-9.5 h to obtain modified aluminum nitride;

[0032] Further, the ratio of nano-zirconia, anhydrous ethanol, and halosilane hydrolysate is 5.5-6.5 g: 40-45 mL: 13-15 mL; the halosilane hydrolysate is obtained by mixing halosilane coupling agent, anhydrous ethanol, and deionized water in a ratio of 12.5-13 g: 15-20 mL: 15-20 mL, and stirring at pH 5.5-6 and temperature 35-40℃ for 4.5-5 h; the halosilane coupling agent is 3-chloropropyltriethoxysilane; the ratio of product m5, product m6, DMSO, methanol, potassium hydroxide ethanol solution, and tetrabutylammonium bromide is 8-9 g: 6.5-7.5 g: 65-70 mL: 10-15 mL: 5-7 mL: 0.3-0.5 g; the mass fraction of potassium hydroxide ethanol solution is 15-20%;

[0033] In step M4, the surface of nano-zirconia is modified by hydrolysis of the halosilane coupling agent to obtain nano-zirconia with chlorine atoms on the surface, i.e., product m6; the hydroxyl group of product m5 reacts with the chlorine atom of product m6 to dehydrochlorinate, and modified aluminum nitride is obtained.

[0034] The beneficial effects of the present invention are as follows: The present invention discloses a highly stable resistive paste and its preparation method. The resistive paste is prepared from raw materials such as a conductive phase, an organic carrier, a glass binder phase, and modified aluminum nitride.

[0035] The modified aluminum nitride used in this invention is obtained by grafting aluminum nitride powder coated with alumina with an amino silane coupling agent, then with tin dioxide powder modified with unsaturated fatty acids and nano-zirconia modified with a halosilane coupling agent. After modification with an aminosilane coupling agent, alumina-coated aluminum nitride powder isolates aluminum nitride from direct contact with lead oxide present or residual in the glass binder phase, preventing the formation of low-melting-point lead aluminate and avoiding a decrease in the stability of the conductor phase of the resistance paste. At the same time, alumina can also inhibit grain boundary migration during sintering, preventing grain coarsening caused by rapid densification of nano-zirconia during sintering. Nano-zirconia inhibits thermal expansion fluctuations through grain boundary pinning effect, enhancing the adhesion strength between modified aluminum nitride and the glass binder phase, avoiding phenomena such as interface peeling and resistance drift caused by thermal expansion coefficient mismatch, and further improving the stability of the resistance paste. In addition, the use of tin dioxide inhibits the volume expansion of zirconia due to phase transformation during the cooling process of the resistance paste after sintering, thereby improving the resistance stability of the resistance paste after multiple sinterings. Detailed Implementation

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] A modified aluminum nitride, the preparation of which includes the following steps:

[0039] Step M1: Mix aluminum isopropoxide, anhydrous ethanol, isopropanol, and deionized water, stir and adjust the pH to 4.8, add pretreated aluminum nitride powder, ultrasonically disperse for 30 min, heat to 60℃, stir for 4 h, let stand for aging for 24 h, dry at 90℃ for 24 h, grind into powder, and perform high-temperature treatment in a nitrogen atmosphere to obtain product m1; the ratio of aluminum isopropoxide, anhydrous ethanol, isopropanol, deionized water, and pretreated aluminum nitride powder is 1 g: 5 mL: 3 mL: 0.5 mL: 0.5 g; the pretreated aluminum nitride powder is obtained by ball milling aluminum nitride (supplier: Yumu (Ningbo) New Materials Co., Ltd., item number YM-ALN-ZLW80) and citric acid at a mass ratio of 9:1 for 11 h, and drying at 100℃; the high-temperature treatment process is to heat to 430℃ at 5℃ / min, hold for 1 h, then heat to 700℃ at 5℃ / min, and hold for 1 h;

[0040] Step M2: Mix product m1 with anhydrous ethanol, sonicate for 35 min, add hydrolysate, and stir at 50℃ for 3 h to obtain product m2; mix undecenoic acid and acetone and stir for 5 min, adjust pH to 5, add pretreated tin dioxide, sonicate at 48℃ for 8 h, wash with n-hexane, and then vacuum dry at 50℃ for 4 h to obtain product m3; the ratio of product m1, anhydrous ethanol, and hydrolysate is 5 g: 30 mL: 10 mL; the hydrolysate is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and the mixed solvent is mixed according to 1... The mixture was prepared by mixing 1.5g and 25mL at a ratio of 1.5g to 25mL, stirring at 45℃ for 1 hour, and then cooling. The solvent was ethanol and water at a volume ratio of 8:1, with ethanol having a volume fraction of 95%. The ratio of undecenoic acid, acetone, and pretreated tin dioxide was 1g:25mL:5g. The pretreated tin dioxide was prepared by soaking tin dioxide (supplier: Shanghai Hanlang New Material Technology Co., Ltd., specification 1kg) in sodium hydroxide solution and ultrasonically vibrating for 6 hours, washing until neutral, and then drying at 105℃ for 2 hours. The concentration of the sodium hydroxide solution was 2mol / L.

[0041] Step M3: Mix product m3, DMF, and anhydrous ethanol and ultrasonically disperse for 40 min. Add m-chloroperoxybenzoic acid and stir at 55℃ for 7 h to obtain product m4. Mix product m2, product m4, DMAc, and methanol and ultrasonically disperse for 1 h. Add tetrabutylammonium chloride and pyridine and stir at 40℃ for 4.5 h to obtain product m5. The ratio of product m3, DMF, anhydrous ethanol, and m-chloroperoxybenzoic acid is 8 g: 35 mL: 10 mL: 2.5 g. The ratio of product m2, product m4, DMAc, methanol, tetrabutylammonium chloride, and pyridine is 7 g: 9 g: 75 mL: 5 mL: 0.5 g: 0.1 g.

[0042] Step M4: Nano-zirconia (supplier: Shijiazhuang Jinghuang Technology Co., Ltd., specification 1kg) and anhydrous ethanol are mixed and ultrasonically dispersed for 35 min. A halosilane hydrolysate is added, and the mixture is stirred at 58℃ for 2 h to obtain product m6. Product m5, product m6, DMSO, and methanol are mixed and ultrasonically dispersed for 50 min. An ethanol solution of potassium hydroxide and tetrabutylammonium bromide are added, and the mixture is heated to 100℃ and refluxed for 9 h to obtain modified aluminum nitride. The ratio of nano-zirconia, anhydrous ethanol, and halosilane hydrolysate is 5:1. 0.5g:40mL:13mL; the halosilane hydrolysis solution was obtained by mixing 3-chloropropyltriethoxysilane, anhydrous ethanol, and deionized water in a ratio of 12.5g:15mL:15mL and stirring at pH 5.5 and 35℃ for 4.5h; the ratio of product m5, product m6, DMSO, methanol, potassium hydroxide ethanol solution, and tetrabutylammonium bromide was 8g:6.5g:65mL:10mL:5mL:0.3g; the mass fraction of potassium hydroxide ethanol solution was 15%.

[0043] Example 2

[0044] A modified aluminum nitride, the preparation of which includes the following steps:

[0045] Step M1: Mix aluminum isopropoxide, anhydrous ethanol, isopropanol, and deionized water, stir and adjust the pH to 5.0, add pretreated aluminum nitride powder, ultrasonically disperse for 35 min, heat to 63℃, stir for 4.3 h, allow to stand for aging for 24.3 h, dry at 95℃ for 24.5 h, grind into powder, and perform high-temperature treatment in a nitrogen atmosphere to obtain product m1; the ratio of aluminum isopropoxide, anhydrous ethanol, isopropanol, deionized water, and pretreated aluminum nitride powder is 1:1. 0.3g:8mL:4mL:0.8mL:0.8g; The pretreated aluminum nitride powder was obtained by ball milling aluminum nitride (supplier: Yumu (Ningbo) New Materials Co., Ltd., item number YM-ALN-ZLW80) and citric acid at a mass ratio of 9.5:1 for 11.5h, and then drying at 105℃; The high-temperature treatment process was to heat to 438℃ at 6℃ / min, hold for 1.3h, and then heat to 720℃ at 6℃ / min and hold for 1.3h.

[0046] Step M2: Mix product m1 with anhydrous ethanol, sonicate for 38 min, add hydrolysate, and stir at 53℃ for 3.3 h to obtain product m2; mix undecenoic acid and acetone and stir for 8 min, adjust pH to 5.3, add pretreated tin dioxide, sonicate at 50℃ for 8.3 h, wash with n-hexane, and then vacuum dry at 53℃ for 4.3 h to obtain product m3; the ratio of product m1, anhydrous ethanol, and hydrolysate is 5.5 g: 33 mL: 11 mL; the hydrolysate is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and the mixed solvent is in a 1:1 ratio. The mixture was prepared by mixing 8g and 28mL at a ratio of 8g to 28mL, stirring at 47℃ for 1.1h, and then cooling. The mixed solvent was ethanol and water at a volume ratio of 8.5:1, with ethanol having a volume fraction of 95%. The ratio of undecenoic acid, acetone, and pretreated tin dioxide was 1.1g:28mL:5.5g. The pretreated tin dioxide was prepared by soaking tin dioxide (supplier: Shanghai Hanlang New Material Technology Co., Ltd., specification 1kg) in sodium hydroxide solution and ultrasonically vibrating for 6.3h, washing until neutral, and then drying at 107℃ for 2.3h. The concentration of the sodium hydroxide solution was 2.3mol / L.

[0047] Step M3: Mix product m3, DMF, and anhydrous ethanol and ultrasonically disperse for 43 min. Add m-chloroperoxybenzoic acid and stir at 58℃ for 7.3 h to obtain product m4. Mix product m2, product m4, DMAc, and methanol and ultrasonically disperse for 1.1 h. Add tetrabutylammonium chloride and pyridine and stir at 45℃ for 5.0 h to obtain product m5. The molar ratio of product m3, DMF, anhydrous ethanol, and m-chloroperoxybenzoic acid is 8.3 g: 37 mL: 13 mL: 2.8 g. The molar ratio of product m2, product m4, DMAc, methanol, tetrabutylammonium chloride, and pyridine is 7.5 g: 9.5 g: 78 mL: 8 mL: 0.6 g: 0.2 g.

[0048] Step M4: Nano-zirconia (supplier: Shijiazhuang Jinghuang Technology Co., Ltd., specification 1kg) and anhydrous ethanol are mixed and ultrasonically dispersed for 37 min. A halosilane hydrolysate is added, and the mixture is stirred at 60℃ for 2.3 h to obtain product m6. Product m5, product m6, DMSO, and methanol are mixed and ultrasonically dispersed for 53 min. An ethanol solution of potassium hydroxide and tetrabutylammonium bromide are added, and the mixture is heated to 105℃ and refluxed for 9.3 h to obtain modified aluminum nitride. The ratio of nano-zirconia, anhydrous ethanol, and halosilane hydrolysate is: 6.0 g : 43 mL : 14 mL; the halosilane hydrolysis solution was obtained by mixing 3-chloropropyltriethoxysilane, anhydrous ethanol, and deionized water in a ratio of 12.8 g : 18 mL : 18 mL and stirring at pH 5.8 and 37 °C for 4.7 h; the ratio of product m5, product m6, DMSO, methanol, potassium hydroxide ethanol solution, and tetrabutylammonium bromide was 8.5 g : 7.0 g : 67 mL : 13 mL : 6 mL : 0.4 g; the mass fraction of potassium hydroxide ethanol solution was 18%.

[0049] Example 3

[0050] A modified aluminum nitride, the preparation of which includes the following steps:

[0051] Step M1: Mix aluminum nitrate, anhydrous ethanol, isopropanol, and deionized water, stir and adjust the pH to 5.2, add pretreated aluminum nitride powder, ultrasonically disperse for 40 min, heat to 65℃, stir for 4.5 h, let stand for aging for 24.5 h, dry at 100℃ for 25 h, grind into powder, and perform high-temperature treatment in a nitrogen atmosphere to obtain product m1; the ratio of aluminum nitrate, anhydrous ethanol, isopropanol, deionized water, and pretreated aluminum nitride powder is 1.5 g: 10 mL: 5 mL: 1 mL: 1 g; the pretreated aluminum nitride powder is obtained by ball milling aluminum nitride (supplier: Yumu (Ningbo) New Materials Co., Ltd., item number YM-ALN-ZLW80) and citric acid at a mass ratio of 10:1 for 12 h, and drying at 110℃; the high-temperature treatment process is to heat to 450℃ at 7℃ / min, hold for 1.5 h, then heat to 750℃ at 7℃ / min, and hold for 1.5 h;

[0052] Step M2: Mix product m1 with anhydrous ethanol, sonicate for 40 min, add hydrolysate, and stir at 55℃ for 3.5 h to obtain product m2; mix undecenoic acid and acetone and stir for 10 min, adjust pH to 5.5, add pretreated tin dioxide, sonicate at 52℃ for 8.5 h, wash with n-hexane, and then vacuum dry at 55℃ for 4.5 h to obtain product m3; the ratio of product m1, anhydrous ethanol, and hydrolysate is 6 g: 35 mL: 12 mL; the hydrolysate is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and the mixed solvent is mixed according to 1... The mixture was prepared by mixing 2g and 30mL at a ratio of 2g to 30mL, stirring at 50℃ for 1.2h, and then cooling. The mixed solvent was ethanol and water at a volume ratio of 9:1, with ethanol having a volume fraction of 95%. The ratio of undecenoic acid, acetone, and pretreated tin dioxide was 1.2g:30mL:6g. The pretreated tin dioxide was prepared by soaking tin dioxide (supplier: Shanghai Hanlang New Material Technology Co., Ltd., specification 1kg) in sodium hydroxide solution and ultrasonically vibrating for 6.5h, washing until neutral, and then drying at 110℃ for 2.5h. The concentration of the sodium hydroxide solution was 2.5mol / L.

[0053] Step M3: Mix product m3, DMF, and anhydrous ethanol and ultrasonically disperse for 45 min. Add m-chloroperoxybenzoic acid and stir at 60℃ for 7.5 h to obtain product m4. Mix product m2, product m4, DMAc, and methanol and ultrasonically disperse for 1.2 h. Add tetrabutylammonium chloride and pyridine and stir at 50℃ for 5.5 h to obtain product m5. The ratio of product m3, DMF, anhydrous ethanol, and m-chloroperoxybenzoic acid is 8.5 g: 40 mL: 15 mL: 3 g. The ratio of product m2, product m4, DMAc, methanol, tetrabutylammonium chloride, and pyridine is 8 g: 10 g: 80 mL: 10 mL: 0.7 g: 0.3 g.

[0054] Step M4: Nano-zirconia (supplier: Shijiazhuang Jinghuang Technology Co., Ltd., specification 1kg) and anhydrous ethanol are mixed and ultrasonically dispersed for 40 min. A halosilane hydrolysate is added, and the mixture is stirred at 62℃ for 2.5 h to obtain product m6. Product m5, product m6, DMSO, and methanol are mixed and ultrasonically dispersed for 55 min. An ethanol solution of potassium hydroxide and tetrabutylammonium bromide are added, and the mixture is heated to 110℃ and refluxed for 9.5 h to obtain modified aluminum nitride. The nano-zirconia, anhydrous ethanol, and halosilane hydrolysate... The dosage ratio was 6.5g:45mL:15mL; the halosilane hydrolysis solution was obtained by mixing 3-chloropropyltriethoxysilane, anhydrous ethanol, and deionized water in a ratio of 13g:20mL:20mL and stirring at pH 6 and 40℃ for 5h; the dosage ratio of product m5, product m6, DMSO, methanol, potassium hydroxide ethanol solution, and tetrabutylammonium bromide was 9g:7.5g:70mL:15mL:7mL:0.5g; the mass fraction of potassium hydroxide ethanol solution was 20%.

[0055] Example 4

[0056] A high-stability resistive paste comprises the following raw materials in parts by weight: 65 parts conductive phase, 30 parts organic carrier, 15 parts glass binder phase, and 2.5 parts modified aluminum nitride; wherein the conductive phase is obtained by mixing ruthenium dioxide and bismuth ruthenate in a mass ratio of 2:1; and the glass binder phase is low-melting-point glass powder (supplier: Anmi Micro-Nano, product grade GT40).

[0057] The organic carrier comprises 30 parts resin, 40 parts solvent, and 15 parts additive; the resin is silicone resin (supplier: Shandong Kafule Polymer Materials Co., Ltd., CFS6528W); the solvent is terpineol; and the additive is oleic acid.

[0058] The high-stability resistive slurry is prepared by the following steps:

[0059] The resin, solvent, and additives were stirred and mixed at 65°C for 35 min, and then cooled to room temperature to obtain an organic carrier. The conductive phase, organic carrier, glass binder phase, and modified aluminum nitride obtained in Example 1 were mixed and stirred at 600 rpm for 30 min, and then ground to obtain a high-stability resistive slurry. The fineness of the high-stability resistive slurry was 3 μm.

[0060] Example 5

[0061] A high-stability resistive paste comprises the following raw materials in parts by weight: 70 parts of conductive phase, 33 parts of organic carrier, 18 parts of glass binder phase, and 3.0 parts of modified aluminum nitride; wherein the conductive phase is obtained by mixing ruthenium dioxide and bismuth ruthenate in a mass ratio of 2.5:1; and the glass binder phase is low-melting-point glass powder (supplier: Anmi Micro-Nano, product grade GT40).

[0062] The organic carrier comprises 35 parts resin, 43 parts solvent, and 18 parts additive; the resin is rosin resin (supplier: Greenlink (Jining) Chemical Technology Co., Ltd., 138 rosin glycerol ester); the solvent is N-methylpyrrolidone; and the additive is polyethylene wax.

[0063] The high-stability resistive slurry is prepared by the following steps:

[0064] The resin, solvent, and additives were stirred and mixed at 70°C for 37 min, and then cooled to room temperature to obtain an organic carrier. The conductive phase, organic carrier, glass binder phase, and modified aluminum nitride obtained in Example 2 were mixed and stirred at 700 rpm for 35 min, and then ground to obtain a high-stability resistive slurry. The fineness of the high-stability resistive slurry was 4 μm.

[0065] Example 6

[0066] A high-stability resistive paste comprises the following raw materials in parts by weight: 75 parts conductive phase, 35 parts organic carrier, 20 parts glass binder phase, and 3.5 parts modified aluminum nitride; the conductive phase is obtained by mixing ruthenium dioxide and bismuth ruthenate in a mass ratio of 3:1; the glass binder phase is low-melting-point glass powder (supplier: Anmi Micro-Nano, product grade GT40).

[0067] The organic carrier comprises 40 parts resin, 45 parts solvent, and 20 parts additive; the resin is ethyl cellulose; the solvent is butyl carbitol; and the additive is polyethylene wax.

[0068] The high-stability resistive slurry is prepared by the following steps:

[0069] The resin, solvent, and additives were stirred and mixed at 75°C for 40 min, and then cooled to room temperature to obtain an organic carrier. The conductive phase, organic carrier, glass binder phase, and modified aluminum nitride obtained in Example 3 were mixed and stirred at 800 rpm for 40 min, and then ground to obtain a high-stability resistive slurry. The fineness of the high-stability resistive slurry was 5 μm.

[0070] Comparative Example 1

[0071] Compared with Example 6, the aluminum nitrate used in the preparation process of the modified aluminum nitride was replaced with ethyl silicate, that is, the aluminum nitride powder was coated with silicon dioxide, and the rest was exactly the same as in Example 6, so as to obtain a high-stability resistive slurry.

[0072] Comparative Example 2

[0073] Compared with Example 6, the tin dioxide used in the preparation process of the modified aluminum nitride was replaced with yttrium oxide, and the rest was exactly the same as in Example 6, to obtain a high-stability resistive paste.

[0074] Comparative Example 3

[0075] Compared with Example 6, the nano-zirconia used in the preparation process of the modified aluminum nitride was replaced with nano-alumina, and the rest was exactly the same as in Example 6, to obtain a high-stability resistive slurry.

[0076] The high-stability resistive slurry prepared according to the present invention was further tested below, and the test results are shown in the figure.

[0077] The resistive pastes obtained in Examples 4-6 and Comparative Examples 1-3 of this invention were screen-printed, leveled, and dried at 160°C for 12 min. They were then sintered in a tunnel oven according to a resistance sintering curve with a peak temperature of 1000°C, a duration of 10 min, and a cooling time of 35 min to obtain resistive samples. The film thickness and resistance of the resistive samples were tested, as were the resistance values ​​after sintering the resistive paste 1, 4, 7, and 10 times. The resistance testing was performed according to SJ / T11512-2015 "Test Methods for Performance of Electronic Pastes for Integrated Circuits".

[0078] The results are recorded in Table 1;

[0079] Table 1: Test Results

[0080]

[0081] According to the data in Table 1, the resistive paste of the present invention still has a relatively stable resistance value after multiple sinterings. Comparing Example 6 with Comparative Example 1, it can be seen that coating the aluminum nitride powder used in the modified aluminum nitride preparation process with silica leads to a decrease in the stability of the conductor phase in the resistive paste, resulting in a decrease in the stability of the resistive paste and a reduction in the resistance stability after multiple sinterings. Comparing Example 6 with Comparative Example 2, it can be seen that replacing tin dioxide used in the modified aluminum nitride preparation process with yttrium oxide reduces the ability to resist the volume expansion caused by the phase transformation of zirconium oxide, resulting in a decrease in the resistance stability after multiple sinterings. Comparing Example 6 with Comparative Example 3, it can be seen that replacing nano-zirconia used in the modified aluminum nitride preparation process with nano-alumina reduces the ability to enhance the adhesion strength between the modified aluminum nitride powder and the glass binder phase, resulting in a decrease in the stability of the resistive paste and a reduction in the resistance stability after multiple sinterings.

[0082] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A high-stability resistive paste, characterized by: The raw materials include the following parts by weight: 65-75 parts of conductive phase, 30-35 parts of organic carrier, 15-20 parts of glass binder phase, and 2.5-3.5 parts of modified aluminum nitride; The modified aluminum nitride is prepared by the following steps: Step M1: Mix aluminum source, anhydrous ethanol, isopropanol, and deionized water, stir and adjust pH, add pretreated aluminum nitride powder, disperse ultrasonically, heat and stir, let stand for aging, dry and grind into powder, and perform high-temperature treatment in a protective gas atmosphere to obtain product m1. The high-temperature treatment process involves raising the temperature to 430-450℃ at a rate of 5-7℃ / min, holding it at that temperature for 1-1.5 hours, and then raising the temperature to 700-750℃ at a rate of 5-7℃ / min, holding it at that temperature for 1-1.5 hours. Step M2: Mix product m1 with anhydrous ethanol, disperse by ultrasonication, add hydrolysate, heat and stir to obtain product m2; mix unsaturated fatty acids and acetone, adjust pH, add pretreated tin dioxide, heat and ultrasonically vibrate, wash with n-hexane, and vacuum dry to obtain product m3. Step M3: After ultrasonically dispersing product m3, DMF, and anhydrous ethanol, add m-chloroperoxybenzoic acid, heat and stir to obtain product m4; after ultrasonically dispersing product m2, product m4, DMAc, and methanol, add tetrabutylammonium chloride and pyridine, heat and stir to obtain product m5. Step M4: After ultrasonically dispersing nano-zirconia and anhydrous ethanol, add halosilane hydrolysate, heat and stir to obtain product m6; after ultrasonically dispersing product m5, product m6, DMSO and methanol, add potassium hydroxide ethanol solution and tetrabutylammonium bromide, heat and reflux and stir to obtain modified aluminum nitride.

2. A high-stability resistive paste according to claim 1, characterized in that: The conductive phase is obtained by mixing ruthenium dioxide and bismuth ruthenate in a mass ratio of 2-3:

1.

3. The high-stability resistive paste of claim 1, wherein: The organic carrier comprises 30-40 parts of resin, 40-45 parts of solvent, and 15-20 parts of additives.

4. The high-stability resistive paste according to claim 3, characterized in that: The resin is selected from one of silicone resin, rosin resin, methylcellulose, ethylcellulose and hydroxycellulose; the solvent is selected from one of terpineol, N-methylpyrrolidone, butylcarbidol and diethylene glycol ethyl ether; the additive is oleic acid or polyethylene wax.

5. The high-stability resistive slurry according to claim 1, characterized in that: In step M2, the hydrolysate is obtained by mixing an aminosilane coupling agent and a mixed solvent at a ratio of 11.5-12g:25-30mL, stirring at 45-50℃ for 1-1.2h, and then cooling; the aminosilane coupling agent is N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

6. The high-stability resistive slurry according to claim 1, characterized in that: In step M2, the unsaturated fatty acid is undecenoic acid.

7. The high-stability resistive slurry according to claim 1, characterized in that: In step M4, the halosilane hydrolysate is obtained by mixing halosilane coupling agent, anhydrous ethanol, and deionized water in a ratio of 12.5-13g:15-20mL:15-20mL and stirring at pH 5.5-6 and temperature 35-40℃ for 4.5-5h; the halosilane coupling agent is 3-chloropropyltriethoxysilane.

8. A method for preparing a high-stability resistive paste according to any one of claims 1-7, characterized in that: Includes the following steps: The conductive phase, organic carrier, glass binder phase, and modified aluminum nitride are mixed and stirred at 600-800 rpm for 30-40 minutes, and then ground to obtain a high-stability resistive slurry.

9. The method for preparing a high-stability resistive paste according to claim 8, characterized in that: The fineness of the high-stability resistive slurry is 3-5 μm.

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