High-energy ball milling preparation method of barium titanate-based semiconductor ceramics

A barium titanate-based, semi-conductive technology, applied in grain processing, etc., can solve the problems of low resistivity, high fine-grained structure, and PTC effect that have not been reported in detail, and achieve fine grain distribution, which is conducive to the oxidation of grain boundaries, The effect of a large lift-to-drag ratio

Inactive Publication Date: 2010-08-18
HUAZHONG UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Judging from the technologies that have been published so far, the US6911102B2 patent uses BaTiO 3 Doped with 0.2% mol or less of nickel and 0.2% to 20% mol of boron as the internal electrode, fired in a reducing atmosphere and re-oxidized, and finally obtained a resistance value of 0.17-3.5Ω, a lift-to-drag ratio The order of magnitude is 2.8-3.6, and the withstand voltage is above 10V, but the room temperature resistivity and grain size are not accur

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0021] 1) BaCO 3 ,TiO 2 , Mn(NO 3 ) 2 , Y 2 o 3 , SrCO 3 Mix according to the molar component ratio of the following compounds.

[0022] BaCO 3 80,TiO 2 101,Y 2 o 3 0.315, Mn(NO 3 ) 2 0.03, SrCO 3 20;

[0023] 2) Weigh 0.6 mol of the mixture and add 3.235 g of silicon dioxide, then ball mill at 350 rpm for 5 hours to obtain a mixed slurry. The mixed slurry was dried, raised to 1200°C at a rate of 200°C / h for 2 hours for pre-calcination, and the solid phase reaction was completed to obtain doped modified barium titanate powder.

[0024] 3) Put the obtained barium titanate powder into an ultra-fine ball mill, filter the slurry with ZrO pellets with a diameter of 1 mm and a gap of 0.5 μm in thickness, the rotating speed is 2200 rpm, the ball milling time is 1 hour, and finally A barium titanate-based PTC powder with a particle size of about 50 nm was obtained.

[0025] 4) Weigh 100g of barium titanate-based ceramic powder, add 22.5g of ethanol and 54.75g...

example 2

[0029] 1) BaCO 3 ,TiO 2 , Mn(NO 3 ) 2 , Y 2 o 3 , SrCO 3 Mix according to the molar component ratio of the following compounds;

[0030] BaCO 3 80,TiO 2 101,Y 2 o 3 0.36, Mn(NO 3 ) 2 0.03, SrCO 3 5. CaCO 3 15;

[0031] 2) Weigh 0.6 mol of the mixture and add 3.237 g of silicon dioxide, then ball mill at 350 rpm for 5 hours to obtain a mixed slurry. Dry the mixed slurry, raise it to 1200°C at a rate of 200°C / h and keep it warm for 2 hours for pre-calcination to complete the solid phase reaction. Then put it into an ultra-fine ball mill at 2200 rpm for 60 minutes and then dry it again, and finally obtain a barium titanate-based ceramic powder with a particle size of about 50 nm.

[0032] 3) Weigh 100g of barium titanate-based ceramic powder, add 22.5g of ethanol and 54.75g of trichlorethylene as an organic solvent, and add 4g of tributyl phosphate as a dispersant for mixing and ball milling at 350 rpm for 3 hours, then add 9.45g polyvinyl butyral res...

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PUM

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Abstract

The invention discloses a method for preparing a barium titanate-based PTC (Positive Temperature Coefficient) semiconductor ceramic fine crystalline structure, which comprises the following steps: using barium carbonate, titanium dioxide, yttrium oxide, manganese nitrate, strontium carbonate or/and calcium carbonate as raw materials, filtering slurry by using ZrO2 spherules with the diameter of 1 to 2mm and a gap with the thickness of 1mum, wherein the rotating speed is 1400 to 2400rpm and the ball milling time is 1 to 3 hours, and finally obtaining barium titanate-based PTC powder with the grain diameter of 20 to 50nm; then adding a dispersant, an adhesive and a plasticizer for mixing and ball milling for 3 to 5 hours, then standing for 5 to 12 hours, removing bubbles, carrying out physical aggregation, and finally carrying out sieving treatment to obtain casting slurry; and finally carrying out casting operation for the casting slurry to prepare a barium titanate ceramic green body. The obtained chip fine crystal PTC is characterized in that the magnetic crystal grain size is below 2 microns, the room temperature resistivity is not more than 120 Omega.cm, the lift-drag ratio is not less than 4*103, and the Curie temperature is 80 to 120 DEG C.

Description

technical field [0001] The invention relates to the manufacture of a chip-type semiconductor ceramic electronic component with a fine-grained structure, in particular to barium titanate (BaTiO 3 ) semiconducting ceramic materials, and electronic components such as thermistors using such ceramic materials. Background technique [0002] BaTiO with a positive temperature coefficient 3 Semiconductor-based ceramics (hereinafter referred to as PTC), as a thermistor component, have been widely used in various equipment and instruments, such as the degaussing of ray tubes in color TV sets, and the overcurrent protection of circuits. [0003] With the rapid development of SMT technology, it has greatly promoted the miniaturization, miniaturization, integration and chip of electronic equipment and electronic components, and the preparation of chip PTCR has become a research hotspot at home and abroad. In order to make the miniaturized chip PTCR element maintain good PTC effect, high...

Claims

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Application Information

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IPC IPC(8): C04B35/468C04B35/622B02C17/00
Inventor 周东祥龚树萍傅邱云刘欢赵俊张波
Owner HUAZHONG UNIV OF SCI & TECH
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