CN105036735A - Z7R-type multilayer ceramic capacitor dielectric material and preparation method thereof - Google Patents

Abstract

The invention discloses a Z7R-type multilayer ceramic capacitor dielectric material and a preparation method thereof. The preparation method comprises the steps: first preparing pure-phase BaTiO3 powder and pure-phase BiYO3 powder; then mixing BaTiO3 powder and BiYO3 powder according to BaTiO3+xmol%BiYO3 to obtain a mixture I, then mixing the mixture I with zirconium ballstone and deionized water, sequentially carrying out ball milling, drying, granulation and sieving, to form a granulated material, wherein X is equal to 4 to 10, and xmol% indicates molar percentage; pressing the granulated material under the pressure of 120MPa to form a test sample, and primarily sintering; polishing and cleaning the primarily sintered test sample, coating the front and back surfaces of the test sample with a silver electrode slurry, and secondarily sintering the test sample to obtain the Z7R-type multilayer ceramic capacitor dielectric material. The Z7R-type ceramic capacitor material prepared by virtue of the method is not only simple in preparation process and low in material cost, but also has high dielectric constant, low dielectric loss, large volume resistivity and good temperature stability and is possible for substituting the lead-base ceramic material to become an important candidate material that is both excellent on technology and economy for a multilayer ceramic capacitor.

Description

A kind of Z7R type medium material for multilayer ceramic capacitors and preparation method thereof

Technical field

The invention belongs to medium material for multilayer ceramic capacitors preparation field, be specifically related to a kind of Z7R type medium material for multilayer ceramic capacitors and preparation method thereof.

Background technology

Along with the develop rapidly of information technology and electronic science and technology, propose higher service requirements to electronics, such as lightness, chip type and miniaturization, laminated ceramic capacitor (MLCC) is just because these reasons are arisen at the historic moment.At present, the dielectric material preparing laminated ceramic capacitor that we commonly use is BaTiO ₃base pottery.Barium titanate specific inductivity at room temperature can reach 1500 ~ 3000, can not produce simultaneously and pollute, be therefore well suited for for dielectric materials in production and application process to environment.But, BaTiO ₃curie temperature be about 120 DEG C, sharply decline higher than specific inductivity during Curie temperature, dielectric loss is large, has influence on the temperature stability of ceramic condenser, therefore, must carry out doping vario-property to barium titanate.Barium titanate based ceramic material after suitable doping vario-property has high-k, low-loss and the little feature of thermal expansivity.

In recent years, laminated ceramic capacitor has started progressively to enter automotive electronics Application Areas, such as control unit of engine (ECU), ABS (Anti-lock Braking System) (ABS), fuel injection program control module (PGMFI) etc., use temperature can reach+150 DEG C, meet such environment for use, need tolerance multiple high temp to run and a large amount of thermal shocking.But the capacitance-temperature characteristic of barium phthalate base material has certain limitation, when temperature is more than 120 DEG C, its temperature coefficient of capacitance (△ C/C _{20 DEG C}) more than 15%, stable dielectric properties cannot be provided.Have EIA (ElectronicIndustriesAssociation, EIA) X7R characteristic (-55 DEG C ~+125 DEG C, △ C/C _{20 DEG C}≤ ± 15%, wherein △ C is with electrical capacity C when 20 DEG C _{20 DEG C}for the electrical capacity C of other temperature spots of benchmark changes △ C=C-C _{20 DEG C}) MLCC be difficult to meet job requirement under above-mentioned hot conditions.Therefore, develop EIAZ7R standard (10 DEG C ~+125 DEG C, △ C/C _{20 DEG C}≤ ± 15%) MLCC receives general concern.

Although, BaTiO ₃base unleaded Z7R type ceramic capacitor dielectric material obtains extensive concern, but, by BiYO ₃doping BaTiO ₃the Z7R type ceramic capacitor dielectric material obtaining temperature-stable also rarely has report.Given this, be necessary to provide a kind of BaTiO that can solve the problem in fact ₃basic ring protects Z7R type ceramic capacitor material and preparation method.

Summary of the invention

The object of the present invention is to provide a kind of Z7R type medium material for multilayer ceramic capacitors and preparation method thereof, to overcome the defect that above-mentioned prior art exists, by the Z7R type ceramic capacitor material that the inventive method is obtained, not only preparation technology is simple, the cost of material is low, and there is, good temperature stability large compared with high specific inductivity, low dielectric loss, body resistivity, likely becoming alternative lead base stupalith becomes laminated ceramic capacitor and to hold concurrently technically and economically excellent important candidate material.

For achieving the above object, the present invention adopts following technical scheme:

A kind of Z7R type medium material for multilayer ceramic capacitors, it is prepared material and comprises BaTiO ₃+ xmol%BiYO ₃, wherein x=4 ~ 10, xmol% represents molar percentage.

A preparation method for Z7R type medium material for multilayer ceramic capacitors, comprises the following steps:

Step one: take BaCO according to mol ratio 1:1 ₃and TiO ₂be mixed to form mixture A, after mixture A is carried out ball milling, oven dry, briquetting, in 1120 ~ 1150 DEG C of insulations 2 ~ 3 hours, form the BaTiO of pure phase ₃powder, for subsequent use;

Step 2: take Bi according to mol ratio 1:1 ₂o ₃and Y ₂o ₃be mixed to form mixture B, after mixture B is carried out ball milling, oven dry, briquetting, in 920 ~ 940 DEG C of insulations 2 ~ 3 hours, form the BiYO of pure phase ₃powder, for subsequent use;

Step 3: the BaTiO that step one is obtained ₃the BiYO that powder and step 2 obtain ₃powder is according to BaTiO ₃+ xmol%BiYO ₃form mixture C after mixing, wherein x=4 ~ 10, x is molar percentage, by mixture C and zirconium ballstone and deionized water, is carry out ball milling, oven dry, granulation successively after 1:1:1 mixing, sieve, forms granulation material according to mass ratio;

Step 4: step 3 gained granulation material is made sample under the pressure of 110 ~ 120MPa, then carries out once sintered;

Step 5: in polishing, cleaning step four after once sintered good sample, evenly apply silver electrode paste at sample tow sides, carry out double sintering, obtain Z7R type medium material for multilayer ceramic capacitors.

Further, in step 3, mixture C mixes with zirconium ballstone and deionized water, ball milling, formed to dry after oven dry and expect, by mass concentration be 4 ~ 6% tackiness agent be added into dry material in carry out granulation, tackiness agent accounts for dries 8 ~ 10% of material quality, after granulation, 40 orders and 80 mesh sieves get middle material excessively respectively, form granulation material.

Further, described tackiness agent is polyvinyl alcohol water solution.

Further, in step 3, Ball-milling Time is 4 ~ 6 hours.

Further, in step 4, once sintered condition is: be warming up to 500 DEG C of insulation 60min with 2 DEG C/min, be incubated 3 hours, afterwards, after being cooled to 500 DEG C, cool to room temperature with the furnace with 5 DEG C/min when being warming up to 1250 ~ 1300 DEG C with 5 DEG C/min.

Further, in step 5, the condition of double sintering is: temperature is 600 ~ 620 DEG C, and the time is 20 ~ 30 minutes.

A preparation method for Z7R type medium material for multilayer ceramic capacitors, comprises the following steps:

Step one: take BaCO according to mol ratio 1:1 ₃and TiO ₂be mixed to form mixture A, after mixture A is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 1150 DEG C of insulations 2 hours, form the BaTiO of pure phase ₃powder, for subsequent use;

Step 2: take Bi according to mol ratio 1:1 ₂o ₃and Y ₂o ₃be mixed to form mixture B, after mixture B is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 940 DEG C of insulations 2 hours, form the BiYO of pure phase ₃powder, for subsequent use;

Step 3: the BaTiO that step one is obtained ₃the BiYO that powder and step 2 obtain ₃powder is according to BaTiO ₃+ 10mol%BiYO ₃mixed in molar ratio after form mixture C, by mixture C and zirconium ballstone and deionized water, be the rear ball milling 4h of 1:1:1 mixing according to mass ratio, then dry formation oven dry material, by mass concentration be 6% polyvinyl alcohol water solution be added into dry material in carry out granulation, polyvinyl alcohol water solution accounts for dries 10% of material quality, after granulation, 40 orders and 80 mesh sieves get middle material excessively respectively, form granulation material;

Step 4: step 3 gained granulation material is made sample under the pressure of 120MPa, then, be placed in zirconium white be backing plate the inherent high temperature box furnace of aluminum oxide saggar in carry out once sintered: be warming up to 500 DEG C of insulation 60min with 2 DEG C/min, 3 hours are incubated when being warming up to 1300 DEG C with 5 DEG C/min, afterwards, after being cooled to 500 DEG C with 5 DEG C/min, cool to room temperature with the furnace;

Step 5: polishing, in cleaning step four after once sintered good sample, evenly apply silver electrode paste at sample tow sides, in 600 DEG C of double sinterings 20 minutes, obtains Z7R type medium material for multilayer ceramic capacitors.

Compared with prior art, the present invention has following useful technique effect:

Z7R type ceramic capacitor material of the present invention, have, good temperature stability large compared with high specific inductivity (during x=10, specific inductivity is 1485), low dielectric loss (tan δ≤0.01), body resistivity, likely becoming alternative lead base stupalith becomes laminated ceramic capacitor and to hold concurrently technically and economically excellent important candidate material.

The inventive method is by BiYO ₃be doped to BaTiO ₃the inside, Bi replaces BaTiO ₃a position, Y replaces BaTiO ₃b position, by doping realize BaTiO ₃the broadening at Curie peak, realize relaxation diffusing phenomenon, thus reach the requirement of unleaded Z7R type ceramic condenser.The inventive method adopts conventional solid-state method preparation, technical maturity, is applicable to industrialization and produces, adopt BiYO ₃adulterate, realize the Diffuse phase transition that valence compensation is conducive to realizing barium titanate ceramics, not only preparation technology is simple for the unleaded Z7R type ceramic capacitor dielectric material prepared of the inventive method, the cost of material is low, and have compared with high specific inductivity, low dielectric loss, body resistivity is large, temperature stability good, laminated ceramic capacitor is become to alternative lead base stupalith and to hold concurrently technically and economically excellent important candidate material.

Accompanying drawing explanation

Fig. 1 is the SEM figure of the sample that embodiment 3 obtains;

Fig. 2 is the temperature variant rational curve of temperature coefficient of capacitance of the sample that embodiment 3 obtains

Fig. 3 is the rational curve of the dielectric constant with temperature change of the sample that embodiment 1-3 obtains;

Fig. 4 is the temperature variant rational curve of dielectric loss of the sample that embodiment 1-3 obtains.

Embodiment

Below embodiments of the present invention are described in further detail:

A preparation method for Z7R type medium material for multilayer ceramic capacitors, comprises the following steps:

Step one: take BaCO according to mol ratio 1:1 ₃and TiO ₂be mixed to form mixture A, after mixture A is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 1120 ~ 1150 DEG C of insulations 2 ~ 3 hours, form the BaTiO of pure phase ₃powder, for subsequent use;

Step 2: take Bi according to mol ratio 1:1 ₂o ₃and Y ₂o ₃be mixed to form mixture B, after mixture B is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 920 ~ 940 DEG C of insulations 2 ~ 3 hours, form the BiYO of pure phase ₃powder, for subsequent use;

Step 3: the BaTiO that step one is obtained ₃the BiYO that powder and step 2 obtain ₃powder is according to BaTiO ₃+ xmol%BiYO ₃mixture C is formed, i.e. BaTiO after mixing ₃molar percentage be (100-x) mol%, BiYO ₃molar percentage be xmol%, BaTiO ₃mole number and BiYO ₃mole number sum equal the mole number of mixture C, wherein x=12 ~ 20, xmol% represents molar percentage, by mixture C and zirconium ballstone and deionized water, according to mass ratio be 1:1:1 mixing after ball milling 4 ~ 6h, then dry formed dry material, by mass concentration be 4 ~ 6% polyvinyl alcohol water solution be added into dry material in carry out granulation, polyvinyl alcohol water solution account for dry material quality 8 ~ 10%, after granulation, 40 orders and 80 mesh sieves get middle material excessively respectively, form granulation material;

Step 4: step 3 gained granulation material is made sample under the pressure of 110 ~ 120MPa, then, be placed in zirconium white be backing plate the inherent high temperature box furnace of aluminum oxide saggar in carry out once sintered: be warming up to 500 DEG C of insulation 60min with 2 DEG C/min, 3 hours are incubated when being warming up to 1250 ~ 1300 DEG C with 5 DEG C/min, afterwards, after being cooled to 500 DEG C with 5 DEG C/min, cool to room temperature with the furnace;

Step 5: polishing, in cleaning step four after once sintered good sample, evenly apply silver electrode paste at sample tow sides, in 600 ~ 620 DEG C of double sinterings 20 ~ 30 minutes, obtains Z7R type medium material for multilayer ceramic capacitors.

Below in conjunction with embodiment, the present invention is described in further detail:

Blank Example

Step one: take BaCO according to mol ratio 1:1 ₃and TiO ₂be mixed to form mixture A, after mixture A is carried out ball milling, oven dry, briquetting, be placed in box-type furnace respectively at 1120 ~ 1150 DEG C of insulations 2 hours, form the BaTiO of pure phase ₃powder, for subsequent use;

Step 2: the BaTiO that step one is obtained ₃powder and zirconium ballstone and deionized water, be carry out ball milling, oven dry, granulation successively after 1:1:1 mixing, sieve according to mass ratio, form granulation material;

Step 3: step 2 gained granulation material is made sample under the pressure of 120MPa, then, be placed in zirconium white be backing plate the inherent high temperature box furnace of aluminum oxide saggar in carry out once sintered, 500 DEG C of insulation 60min are warming up to 2 DEG C/min, 3 hours are incubated when being warming up to 1250 ~ 1300 DEG C with 5 DEG C/min, afterwards, after being cooled to 500 DEG C with 5 DEG C/min, room temperature is cooled to the furnace;

Step 4: polishing, in cleaning step three after once sintered good sample, evenly apply silver electrode paste at sample tow sides, in 600 DEG C of double sinterings 20 minutes, obtains blank sample.

Embodiment 1

Step one: take BaCO according to mol ratio 1:1 ₃and TiO ₂be mixed to form mixture A, after mixture A is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 1120 DEG C of insulations 3 hours, form the BaTiO of pure phase ₃powder, for subsequent use;

Step 2: take Bi according to mol ratio 1:1 ₂o ₃and Y ₂o ₃be mixed to form mixture B, after mixture B is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 920 DEG C of insulations 3 hours, form the BiYO of pure phase ₃powder, for subsequent use;

Step 3: the BaTiO that step one is obtained ₃the BiYO that powder and step 2 obtain ₃powder is according to BaTiO ₃+ 4mol%BiYO ₃mol ratio mixing after form mixture C, by mixture C and zirconium ballstone and deionized water, be the rear ball milling 6h of 1:1:1 mixing according to mass ratio, then dry formation oven dry material, by mass concentration be 4% polyvinyl alcohol water solution be added into dry material in carry out granulation, polyvinyl alcohol water solution accounts for dries 8% of material quality, after granulation, 40 orders and 80 mesh sieves get middle material excessively respectively, form granulation material;

Step 4: step 3 gained granulation material is made sample under the pressure of 110MPa, then, be placed in zirconium white be backing plate the inherent high temperature box furnace of aluminum oxide saggar in carry out once sintered: be warming up to 500 DEG C of insulation 60min with 2 DEG C/min, 3 hours are incubated when being warming up to 1250 DEG C with 5 DEG C/min, afterwards, after being cooled to 500 DEG C with 5 DEG C/min, cool to room temperature with the furnace;

Step 5: polishing, in cleaning step four after once sintered good sample, evenly apply silver electrode paste at sample tow sides, in 620 DEG C of double sinterings 30 minutes, obtains Z7R type medium material for multilayer ceramic capacitors.

Embodiment 2

Step one: take BaCO according to mol ratio 1:1 ₃and TiO ₂be mixed to form mixture A, after mixture A is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 1130 DEG C of insulations 2.5 hours, form the BaTiO of pure phase ₃powder, for subsequent use;

Step 2: take Bi according to mol ratio 1:1 ₂o ₃and Y ₂o ₃be mixed to form mixture B, after mixture B is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 930 DEG C of insulations 2.5 hours, form the BiYO of pure phase ₃powder, for subsequent use;

Step 3: the BaTiO that step one is obtained ₃the BiYO that powder and step 2 obtain ₃powder is according to BaTiO ₃+ 6mol%BiYO ₃mixed in molar ratio after form mixture C, by mixture C and zirconium ballstone and deionized water, be the rear ball milling 5h of 1:1:1 mixing according to mass ratio, then dry formation oven dry material, by mass concentration be 5% polyvinyl alcohol water solution be added into dry material in carry out granulation, polyvinyl alcohol water solution accounts for dries 9% of material quality, after granulation, 40 orders and 80 mesh sieves get middle material excessively respectively, form granulation material;

Step 4: step 3 gained granulation material is made sample under the pressure of 115MPa, then, be placed in zirconium white be backing plate the inherent high temperature box furnace of aluminum oxide saggar in carry out once sintered: be warming up to 500 DEG C of insulation 60min with 2 DEG C/min, 3 hours are incubated when being warming up to 1280 DEG C with 5 DEG C/min, afterwards, after being cooled to 500 DEG C with 5 DEG C/min, cool to room temperature with the furnace;

Step 5: polishing, in cleaning step four after once sintered good sample, evenly apply silver electrode paste at sample tow sides, in 610 DEG C of double sinterings 25 minutes, obtains Z7R type medium material for multilayer ceramic capacitors.

Embodiment 3

Step one: take BaCO according to mol ratio 1:1 ₃and TiO ₂be mixed to form mixture A, after mixture A is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 1150 DEG C of insulations 2 hours, form the BaTiO of pure phase ₃powder, for subsequent use;

Step 2: take Bi according to mol ratio 1:1 ₂o ₃and Y ₂o ₃be mixed to form mixture B, after mixture B is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 940 DEG C of insulations 2 hours, form the BiYO of pure phase ₃powder, for subsequent use;

Step 3: the BaTiO that step one is obtained ₃the BiYO that powder and step 2 obtain ₃powder is according to BaTiO ₃+ 10mol%BiYO ₃mixed in molar ratio after form mixture C, by mixture C and zirconium ballstone and deionized water, be the rear ball milling 4h of 1:1:1 mixing according to mass ratio, then dry formation oven dry material, by mass concentration be 6% polyvinyl alcohol water solution be added into dry material in carry out granulation, polyvinyl alcohol water solution accounts for dries 10% of material quality, after granulation, 40 orders and 80 mesh sieves get middle material excessively respectively, form granulation material;

Step 4: step 3 gained granulation material is made sample under the pressure of 120MPa, then, be placed in zirconium white be backing plate the inherent high temperature box furnace of aluminum oxide saggar in carry out once sintered: be warming up to 500 DEG C of insulation 60min with 2 DEG C/min, 3 hours are incubated when being warming up to 1300 DEG C with 5 DEG C/min, afterwards, after being cooled to 500 DEG C with 5 DEG C/min, cool to room temperature with the furnace;

Step 5: polishing, in cleaning step four after once sintered good sample, evenly apply silver electrode paste at sample tow sides, in 600 DEG C of double sinterings 20 minutes, obtains Z7R type medium material for multilayer ceramic capacitors.

As shown in Figure 4, dielectric properties test show: the ceramic medium material prepared by embodiment 3 all meet EIAZ7R standard (10 DEG C ~+125 DEG C, △ C/C _{20 DEG C}≤ ± 15%), concrete parameters as shown in Table 1.By doping BiYO ₃, and and BaTiO ₃form sosoloid, effectively can improve Curie temperature, Curie peak be moved to high temperature direction, can also reduce sintering temperature, as shown in Figure 1, the pottery of sample 3 is dense.Meanwhile, form the fluctuating of micro components, composition fluctuation theory proposes based on compound ion stochastic distribution phenomenon.Think that different ions such as to occupy at random at the isomorphous position, produce microscopic concentration and the different microcell of integral macroscopic concentration, form different microcell and there is slightly different Curie temperature, macroscopically produce the transition temperature area of broadening, even if the average component of microcell is identical, also may form the different microcell of structure due to cell configuration difference, thus produce Diffuse phase transition.By adulterating or changing the scantlings of the structure of crystal grain, the Curie peak of ferroelectric ceramic(s) can be made to raise, the specific inductivity of peak value both sides rises, namely ε-T curve becomes more extensive, smooth, this by adulterating or changing the effect that crystalline-granular texture size improves the temperature stability of ceramic dielectric constant, be called broadening effect.Barium titanate-based lead-free Z7R type ceramic capacitor dielectric material prepared by the present invention, not only preparation technology is simple, the cost of material is low, and have compared with high specific inductivity, low dielectric loss, body resistivity is large, temperature stability is good, being expected to alternative lead base stupalith becomes laminated ceramic capacitor and to hold concurrently technically and economically one of excellent important candidate material.

Claims (8)

1. a Z7R type medium material for multilayer ceramic capacitors, is characterized in that, it is prepared material and comprises BaTiO ₃+ xmol%BiYO ₃, wherein x=4 ~ 10, xmol% represents molar percentage.

2. a preparation method for Z7R type medium material for multilayer ceramic capacitors, is characterized in that, comprises the following steps:

Step one: take BaCO according to mol ratio 1:1 ₃and TiO ₂be mixed to form mixture A, after mixture A is carried out ball milling, oven dry, briquetting, in 1120 ~ 1150 DEG C of insulations 2 ~ 3 hours, form the BaTiO of pure phase ₃powder, for subsequent use;

Step 2: take Bi according to mol ratio 1:1 ₂o ₃and Y ₂o ₃be mixed to form mixture B, after mixture B is carried out ball milling, oven dry, briquetting, in 920 ~ 940 DEG C of insulations 2 ~ 3 hours, form the BiYO of pure phase ₃powder, for subsequent use;

Step 3: the BaTiO that step one is obtained ₃the BiYO that powder and step 2 obtain ₃powder is according to BaTiO ₃+ xmol%BiYO ₃form mixture C after mixing, wherein x=4 ~ 10, x is molar percentage, by mixture C and zirconium ballstone and deionized water, is carry out ball milling, oven dry, granulation successively after 1:1:1 mixing, sieve, forms granulation material according to mass ratio;

Step 4: step 3 gained granulation material is made sample under the pressure of 110 ~ 120MPa, then carries out once sintered;

Step 5: in polishing, cleaning step four after once sintered good sample, evenly apply silver electrode paste at sample tow sides, carry out double sintering, obtain Z7R type medium material for multilayer ceramic capacitors.

3. the preparation method of a kind of Z7R type medium material for multilayer ceramic capacitors according to claim 2, it is characterized in that, in step 3, mixture C mixes with zirconium ballstone and deionized water, ball milling, formed to dry after oven dry and expect, by mass concentration be 4 ~ 6% tackiness agent be added into dry material in carry out granulation, tackiness agent accounts for dries 8 ~ 10% of material quality, crosses 40 orders and 80 mesh sieves respectively and gets middle material, form granulation material after granulation.

4. the preparation method of a kind of Z7R type medium material for multilayer ceramic capacitors according to claim 3, it is characterized in that, described tackiness agent is polyvinyl alcohol water solution.

5. the preparation method of a kind of Z7R type medium material for multilayer ceramic capacitors according to claim 2, it is characterized in that, in step 3, Ball-milling Time is 4 ~ 6 hours.

6. the preparation method of a kind of Z7R type medium material for multilayer ceramic capacitors according to claim 2, it is characterized in that, in step 4, once sintered condition is: be warming up to 500 DEG C of insulation 60min with 2 DEG C/min, 3 hours are incubated when being warming up to 1250 ~ 1300 DEG C with 5 DEG C/min, afterwards, after being cooled to 500 DEG C with 5 DEG C/min, cool to room temperature with the furnace.

7. the preparation method of a kind of Z7R type medium material for multilayer ceramic capacitors according to claim 2, it is characterized in that, in step 5, the condition of double sintering is: temperature is 600 ~ 620 DEG C, and the time is 20 ~ 30 minutes.

8. a preparation method for Z7R type medium material for multilayer ceramic capacitors, is characterized in that, comprises the following steps:

Step one: take BaCO according to mol ratio 1:1 ₃and TiO ₂be mixed to form mixture A, after mixture A is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 1150 DEG C of insulations 2 hours, form the BaTiO of pure phase ₃powder, for subsequent use;

Step 2: take Bi according to mol ratio 1:1 ₂o ₃and Y ₂o ₃be mixed to form mixture B, after mixture B is carried out ball milling, oven dry, briquetting, be placed in box-type furnace in 940 DEG C of insulations 2 hours, form the BiYO of pure phase ₃powder, for subsequent use;

Step 3: the BaTiO that step one is obtained ₃the BiYO that powder and step 2 obtain ₃powder is according to BaTiO ₃+ 10mol%BiYO ₃mixed in molar ratio after form mixture C, by mixture C and zirconium ballstone and deionized water, be the rear ball milling 4h of 1:1:1 mixing according to mass ratio, then dry formation oven dry material, by mass concentration be 6% polyvinyl alcohol water solution be added into dry material in carry out granulation, polyvinyl alcohol water solution accounts for dries 10% of material quality, after granulation, 40 orders and 80 mesh sieves get middle material excessively respectively, form granulation material;

Step 4: step 3 gained granulation material is made sample under the pressure of 120MPa, then, be placed in zirconium white be backing plate the inherent high temperature box furnace of aluminum oxide saggar in carry out once sintered: be warming up to 500 DEG C of insulation 60min with 2 DEG C/min, 3 hours are incubated when being warming up to 1300 DEG C with 5 DEG C/min, afterwards, after being cooled to 500 DEG C with 5 DEG C/min, cool to room temperature with the furnace;

Step 5: polishing, in cleaning step four after once sintered good sample, evenly apply silver electrode paste at sample tow sides, in 600 DEG C of double sinterings 20 minutes, obtains Z7R type medium material for multilayer ceramic capacitors.