CN102010198A - Ceramic capacitor dielectric material - Google Patents

Abstract

The invention discloses a ceramic capacitor dielectric material, which is characterized by consisting of three parts in percentage by weight, namely 85 to 92 percent of zinc barium titanite serving as a principal component, 3 to 8 percent of modified dopant and 3 to 10 percent of glass flux. The dielectric material adopts zinc-doped barium titanate generated through an oxalate method as a main material, is a ceramic dielectric material sintered at lower temperature and meeting EIA (electronic industries association) X7R temperature characteristic, matches a palladium/silver alloy inner electrode with 20/80 and even lower palladium content to prepare a multi-layer ceramic capacitor, and guarantees that a capacitor component has excellent electrical property and the material cost can be obviously reduced.

Description

A kind of ceramic capacitor dielectric material

Technical field

The present invention relates to a kind of ceramic capacitor dielectric material.

Background technology

Laminated ceramic capacitor (be called for short MLCC) is a kind of with the electrical condenser of pottery as medium, owing to MLCC has small volume, high reliability, is suitable for advantage such as surface mount and becomes the more passive electronic components of consumption in various electronic circuits.The ceramic medium material that MLCC uses comprises with the barium titanate being the class dielectric material with X7R temperature profile in the EIA standard of base, and electrode has good MLCC electrical property at 1100 ℃ of left and right sides sintering in the palladium/silver alloys of such match materials 30/70.Such as at MLCC products such as mesohigh, low ESR, radio frequency, microwaves, major part is as interior electrode with palladium/silver alloys.Because the price of precious metal palladium is higher, causes corresponding M LCC material cost higher, is unfavorable for the development of enterprise.

Summary of the invention

Purpose of the present invention, be that a kind of ceramic capacitor dielectric material will be provided, this dielectric material adopts the zinc doping barium titanate of oxalate method production as main material, agglomerating has the ceramic medium material that meets EIA standard x 7R temperature profile at a lower temperature, coupling 20/80 in addition more in the palladium/silver alloys of low palladium content electrode make laminated ceramic capacitor, when guaranteeing that capacity cell has excellent electrical properties, can significantly reduce material cost; And do not add harmful elements such as lead, cadmium, meet the requirement of present environmental protection aspect.

The present invention is achieved in that described a kind of ceramic capacitor dielectric material, it is characterized in that: described ceramic medium material is made up of principal constituent zinc titanate barium, modification hotchpotch and glass thing three parts of fluxing, and is specific as follows;

1) zinc titanate barium, molecular formula are Ba_1-xZn_xTiO₃, 0.01≤x≤0.06 wherein; Ba_1-xZn_xTiO₃In ceramic medium material, account for 85～92wt%;

2) the modification hotchpotch comprises SrO, Y₂O₃, Nb₂O₅, MnO₂, R₂O₃R is at least a among La, Ce, Nd, the Sm; Each oxide compound in the modification hotchpotch accounts for the SrO of 1～4wt%, the Y of 0.5～1.5 wt% in ceramic medium material₂O₃, 1～4 wt% Nb₂O₅, 0.1～0.4 wt% MnO₂, 0.3～1.5 wt% R₂O₃The modification hotchpotch accounts in ceramic medium material: 3～8wt%;

3) the glass thing of fluxing is a kind of Al of consisting of₂O₃-SiO₂-ZnO-CuO-V₂O₅Glass powder; It consists of: the Al of 5～10wt%₂O₃, the SiO of 10～20wt%₂, the ZnO of 15～25wt%, the CuO of 20～35wt%, the V of 30～45wt%₂O₅The glass thing of fluxing accounts for 3～10wt% in ceramic medium material.

Zinc titanate barium of the present invention is the zinc doping barium titanate of producing with oxalate method.

The invention has the beneficial effects as follows that this ceramic capacitor dielectric material has superior dielectric properties, sintering at a lower temperature, electrode preparation laminated ceramic capacitor in the palladium/silver alloys of coupling low palladium content obviously reduces its material cost.

Embodiment

The ceramic medium material preparation process that the present invention relates to is as follows:

1, the glass preparation of thing of fluxing: by the Al of 5～10wt%₂O₃, the SiO of 10～20 wt%₂, the ZnO of 15～25 wt%, the CuO of 20～35 wt%, the V of 30～45wt%₂O₅Each divided oxide another name is heavy, mix and place ball mill, in powder: water=1:(1～1.5) ratio add deionized water, the ball milling time is 15～25 hours, after ball milling mixes, carry out drying, pulverizing, 1150 ℃～1300 ℃ fusions 1～3 hour, pour quenching in the water then into, after superfine grinding, filtration, oven dry, obtain the glass of the present invention thing (glass powder) of fluxing.

2, according to the principal constituent zinc titanate barium that consists of 85～92wt%, the SrO of 1～4wt%, the Y of 0.5～1.5wt%₂O₃, 1～4 wt% Nb₂O₅, 0.1～0.4 wt% MnO₂, 0.3～1.5 wt% R₂O₃, R is at least a among La, Ce, Nd, the Sm, the glass of the 3～10wt% various materials of thing weighing of fluxing mix placing ultra-fine grinding mill to carry out superfine grinding, require the powder average particle size particle size less than 0.7 micron for well; Drying, pulverizing then obtains ceramic medium material powder of the present invention at last.

Embodiment

(1) with analytically pure Al₂O₃, SiO₂, ZnO, CuO, V₂O₅Be starting material, press the proportion of composing of table 1, after operations such as ball milling, drying, fusion, quenching, pulverizing, filtration, oven dry, make glass powder by 1 described glass powder preparation process in the summary of the invention.

(2) press the composition of table 2, main material is with oxalate method synthetic analytical pure Ba_1-xZn_xTiO₃(0.01≤x≤0.06) adds analytically pure SrO, Y₂O₃, Nb₂O₅, MnO₂, R₂O₃Glass powder described in (R be among La, Ce, Nd, the Sm at least a) and (1) adds deionized water and carry out superfine grinding in ball mill, makes ceramic medium material powder of the present invention after the oven dry.

(3) process of preparation electrical condenser sample: in the ceramic medium material described in (2), add the granulation of PVA based adhesive, the pressure that applies 10MPa is made the disk parison body of 10 millimeters of thick 1.5 millimeters, diameter, the design temperature curve is warming up to 900 ℃～1050 ℃ sintering in the air atmosphere stove then, ceramic plate coated on both sides silver slurry behind sintering, place electric furnace to be warming up to 750 ℃～820 ℃ burning infiltration silver electrodes, form the wafer capacitance device, every electrical property of test wafer capacitance device, test result is listed in the table 3.

 

The Example formulations of table 1 glass powder

Table 2 embodiments of the invention sample chemical constitution

The sintering condition of table 3 embodiments of the invention sample and electric performance test result

As can be seen from Table 3, the embodiments of the invention sample is sintering in 900 ℃～1050 ℃ temperature range, and room temperature dielectric constant is between 2000～3000, and electrical property satisfies the requirement of X7R temperature profile.This material is used for laminated ceramic capacitor, can with 20% in addition more palladium/the silver alloys of low palladium content reduce the material cost of capacitor fabrication as interior electrode.

Claims (2)

1. ceramic capacitor dielectric material is characterized in that: described ceramic medium material is made up of principal constituent zinc titanate barium, modification hotchpotch and glass thing three parts of fluxing, and is specific as follows;

1) zinc titanate barium, molecular formula are Ba_1-xZn_xTiO₃, 0.01≤x≤0.06 wherein; Ba_1-xZn_xTiO₃In ceramic medium material, account for 85～92wt%;

2) the modification hotchpotch comprises SrO, Y₂O₃, Nb₂O₅, MnO₂, R₂O₃R is at least a among La, Ce, Nd, the Sm; Each oxide compound in the modification hotchpotch accounts for the SrO of 1～4wt%, the Y of 0.5～1.5 wt% in ceramic medium material₂O₃, 1～4 wt% Nb₂O₅, 0.1～0.4 wt% MnO₂, 0.3～1.5 wt% R₂O₃The modification hotchpotch accounts for 3～8wt% in ceramic medium material;

3) the glass thing of fluxing is a kind of Al of consisting of₂O₃-SiO₂-ZnO-CuO-V₂O₅Glass powder; It consists of: the Al of 5～10wt%₂O₃, the SiO of 10～20wt%₂, the ZnO of 15～25wt%, the CuO of 20～35wt%, the V of 30～45wt%₂O₅The glass thing of fluxing accounts for 3～10wt% in ceramic medium material.

2. according to the described a kind of ceramic capacitor dielectric material of claim 1, it is characterized in that: described zinc titanate barium is the zinc doping barium titanate of producing with oxalate method.