X8R type capacitor dielectric ceramic material and preparation method thereof

Abstract

The invention discloses an X8R type capacitor dielectric ceramic material and a preparation method thereof. The ceramic material comprises the following components: (1-x) BaTiO3-xBi [(Mg2 / 3Ta1 / 3) 1-0.015 x Nb 0.015 x] O < 3 + > 0.015 x, MnO2 and ZnO, the preparation method comprises the following steps: taking BaCO3, Bi2O3, TiO2, MgO, Ta2O5 and Nb2O5 as raw materials, mixing, drying and calcining through a solid-phase reaction method to obtain main crystalline phase powder, then mixing the main crystalline phase powder with MnO2 and ZnO, and carrying out ball milling, molding and sintering to obtain the ceramic material. The ceramic material provided by the invention has a fine-grain compact structure, and not only has a relatively high dielectric constant and extremely low dielectric loss, but also has a dielectric constant temperature change rate meeting the EIA X8R standard.

Description

Technical Field

[0001] This invention relates to a barium titanate-based capacitor ceramic material and its preparation method, and more particularly to an X8R type capacitor dielectric ceramic material and its preparation method. Background Technology

[0002] As a core component of consumer electronics, ceramic capacitors are continuously driven by market demand, fueling technological innovation. Among them, X8R type capacitors, with a capacitance change rate of only ±15% within the -55℃ to +150℃ temperature range, have become the preferred choice for high-stability circuits (such as coupling and filtering). Barium titanate (BaTiO3) is commonly used in electronic devices, but it undergoes ferroelectric-ferroelectric or ferroelectric-paraelectric phase transitions near -90℃, 5℃, and 120℃, causing drastic fluctuations in the dielectric constant within the phase transition temperature range, affecting the stability and reliability of the devices. With the development of electronic devices towards miniaturization, high reliability, and large capacitance, ceramic dielectric materials face the synergistic technical challenges of high dielectric constant, low dielectric loss, and low capacitance temperature change rate. Therefore, developing ceramic dielectric materials with high dielectric temperature stability has become an important research direction in the field of multilayer ceramic capacitors.

[0003] To overcome the aforementioned problems, it is often necessary to modify barium titanate materials. For example, the journal *Journal of the European Ceramic Society*, Volume 32, 2012, published an article entitled "A quick method to determine the capacity characteristics of thin layer X5R multilayer capacitors," which disclosed a method for preparing xmol% YO2 by a solid-state method. 1.5BaTiO3 ceramics doped with 0.4 mol% MgO, 0.2 mol% MnCO3, and 1.0 mol% SiO2 exhibit a room temperature dielectric constant exceeding 3500 when x=0.30, but the rate of change of the dielectric constant with temperature only meets ±15% within a narrow temperature range (-55~+85℃). The journal *Journal of Electronic Materials*, Volume 44, Issue 3, 2015, disclosed an electronic material co-doped with 10 wt.% LiF / CuO (1:1) BaTiO3, which, when sintered at 860℃, achieves a density of 95% and a room temperature dielectric constant of 1620 at 1 MHz, but the rate of change of the dielectric constant with temperature only meets ±15% within a narrow temperature range (-55~+85℃). The journal *Journal of Alloys and Compounds*, 2014, Vol. 586, pp. 136-141, in the article "Novel X7R BaTiO3 ceramics co-doped with La..." 3+ and Ca 2+ The article "ions" discloses a (Ba 1- x La x (Ti) 1-x / 2 Ca x / 2 O3 ceramics, the sample with x=0.03, although possessing a high dielectric constant (ε) r =2000), but its dielectric temperature stability only meets the X7R standard and has high dielectric loss.

[0004] Therefore, there is an urgent need for a barium titanate-based capacitor ceramic material that not only has a high dielectric constant and low dielectric loss, but also satisfies the requirement of dielectric temperature stability over an ultra-wide temperature range. Summary of the Invention

[0005] Purpose of the invention: The purpose of this invention is to provide an X8R type capacitor dielectric ceramic material that has a high dielectric constant and low dielectric loss, while simultaneously satisfying the requirement of dielectric temperature stability over an ultra-wide temperature range.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned X8R type capacitor dielectric ceramic material.

[0007] Technical solution: The X8R type capacitor dielectric ceramic material of the present invention comprises the following components by mass percentage:

[0008] (1-x)BaTiO3-xBi[(Mg 2 / 3 Ta 1 / 3 )1-0.015x Nb 0.015x ]O 3+0.015x 99.5-99.7 wt%

[0009] ZnO 0.15-0.25wt%;

[0010] MnO2 0.15-0.25wt%;

[0011] Where x = 0.18~0.22.

[0012] The above-mentioned method for preparing the dielectric ceramic material of the X8R type capacitor includes the following steps:

[0013] (1) Mix BaCO3, Bi2O3, MgO, Ta2O5, Nb2O5 and TiO2 in a molar ratio of (1-x):x / 2:2x(1-0.015x) / 3:x(1-0.015x) / 6:0.015x 2 The main crystalline phase powder was obtained by mixing / 2:(1-x) and then ball milling, drying, and calcining.

[0014] (2) Add ZnO and MnO2 to the main crystalline phase powder according to the mass percentage, and obtain a green body by ball milling, drying, granulation and molding. The green body is then debonded and sintered to obtain capacitor ceramic material.

[0015] In steps (1) and (2), the ball milling involves mixing and grinding the ingredients, grinding balls, and deionized water at a mass ratio of 1:1.5~3:2.5~3.5 for 4~6 hours.

[0016] In step (1), in order to ensure the full synthesis of the main crystalline phase and to suppress the volatilization of Bi as much as possible, the calcination is carried out at 1050℃~1100℃ for 2~3h; the heating rate is 4~6℃ / min.

[0017] In step (2), in order to suppress the volatilization of Bi, the sintering is carried out by sintering in a buckling manner.

[0018] In step (2), in order to avoid underfiring or overfiring and to ensure dense sintering of the ceramic material, the sintering is carried out at 1320~1360℃ for 1~3h; the heating rate is 4~6℃ / min.

[0019] In step (2), the granulation process uses a polyvinyl alcohol aqueous solution with a concentration of 4-6 wt%.

[0020] In step (2), the glue removal is first kept at 150~250℃ for 25~35min, and then kept at 550~650℃ for 25~35min.

[0021] Invention principle: This invention utilizes Nb 5+ Ion partial substitution (Mg) 2 / 3 Ta 1 / 3 ) 3+ Equivalent B-site ions are used to form a BiFeO3-like perovskite system, which is further combined with ordinary ferroelectric BaTiO3 to form a dual-composite main crystalline phase at the A and B sites. Through the synergistic effect of the main crystalline phase and the secondary modifiers MnO2 and ZnO, the ceramic material has a fine-grained and dense structure, as well as a high dielectric constant and low dielectric loss. As the long-range order of the BaTiO3 ferroelectric domains is gradually destroyed and polar nanodomains are gradually formed, this composite system exhibits significant relaxor ferroelectric properties, thus keeping the dielectric constant temperature change rate stable over an ultra-wide temperature range, meeting the X8R standard, i.e., the dielectric constant change rate is less than ±15% in the temperature range of -55℃ to 150℃.

[0022] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects: (1) The ceramic material of the present invention has a fine-grained and dense structure, which not only has a high dielectric constant and extremely low dielectric loss, but also has a dielectric constant temperature change rate that meets the EIA X8R standard. (2) The present invention uses Nb 5+ In Bi(Mg 2 / 3 Ta 1 / 3 After relaxation enhancement is achieved by modifying the B-site donor of the O3 perovskite lattice, it is further compounded with ordinary ferroelectric BaTiO3, which not only takes into account the high dielectric constant, but also achieves ultra-high dielectric temperature stability through dispersion phase transition. Attached Figure Description

[0023] Figure 1 This is a microscopic morphology image of the ceramic material prepared in Example 2 of the present invention;

[0024] Figure 2 This is a graph showing the temperature change rate of the dielectric constant of the ceramic material prepared in Example 2 of the present invention. Detailed Implementation

[0025] The present invention will now be described in further detail.

[0026] Example 1

[0027] The main crystalline phase powder of this ceramic material has the chemical formula: 0.82BaTiO3-0.18Bi[(Mg 2 / 3 Ta 1 / 3 ) 0.9973 Nb 0.0027 ]O 3.0027 x=0.18.

[0028] The composition of this ceramic material is shown in Table 1 below:

[0029] Table 1. Components and their contents in Example 1

[0030]

[0031] The preparation method of this ceramic material includes the following steps:

[0032] (1) Weigh BaCO3, Bi2O3, MgO, Ta2O5, Nb2O5 and TiO2 in a molar ratio of 0.82:0.09:0.119682:0.029925:0.000243:0.82, mix them to prepare the ingredients, and put the ingredients into a ball mill jar with agate grinding ball and deionized water in a mass ratio of 1:1.5:2.5. Wet ball milling is carried out for 6 hours to obtain a slurry. Then the slurry is dried at 135℃ and calcined at 1080℃ at a rate of 5℃ / min for 2 hours to synthesize the main crystalline phase powder by solid-phase reaction.

[0033] (2) Add ZnO and MnO2 to the main crystalline phase powder according to the mass fraction in Table 1, and wet ball mill with agate grinding ball and deionized water at a mass ratio of 1:1.5:2.5 for 6 hours. Then dry at 135℃, add 4wt% polyvinyl alcohol (PVA) aqueous solution to granulate, pass through a 40-mesh sieve, and mold to obtain Φ10mm sheet blank;

[0034] (3) The above-mentioned blank is placed on a ceramic pad with dispersed zirconium dioxide pad material and fired. First, the binder is removed at 150°C for 30 minutes, and then the binder is removed at 600°C for 30 minutes. The heating rate is controlled at 5°C / min to raise the temperature to 1350°C and sinter for 1 hour to form ceramic. Finally, the ceramic is cooled to room temperature with the furnace to obtain capacitor ceramic material.

[0035] The capacitor dielectric ceramic material prepared in this embodiment is sintered densely, with a room temperature dielectric constant of 800, a room temperature dielectric loss of 0.005, and a dielectric constant temperature change rate of +1.1% to -15.0% in the range of -55℃ to +150℃.

[0036] Example 2

[0037] The main crystalline phase powder of this ceramic material has the chemical formula: 0.8BaTiO3-0.2Bi[(Mg 2 / 3 Ta 1 / 3 ) 0.997 Nb 0.003 ]O 3.003 x=0.2.

[0038] The composition of this ceramic material is shown in Table 2 below:

[0039] Table 2. Components and their contents in Example 2

[0040]

[0041] The preparation method of this ceramic material includes the following steps:

[0042] (1) Weigh BaCO3, Bi2O3, MgO, Ta2O5, Nb2O5 and TiO2 in a molar ratio of 0.8:0.1:0.13294:0.03324:0.0003:0.8, mix them to prepare the ingredients, and put the ingredients into a ball mill jar with agate grinding ball and deionized water in a mass ratio of 1:1.5:2.5. Wet ball milling is carried out for 6 hours to obtain a slurry. Then the slurry is dried at 135℃ and calcined at 1080℃ at a rate of 5℃ / min for 2 hours to synthesize the main crystalline phase powder by solid-phase reaction.

[0043] (2) Add ZnO and MnO2 to the main crystalline phase powder according to the mass fraction in Table 2, and wet ball mill with agate grinding ball and deionized water at a mass ratio of 1:1.5:2.5 for 6 hours. Then dry at 135℃, add 4wt% polyvinyl alcohol (PVA) aqueous solution to granulate, pass through a 40-mesh sieve, and mold to obtain Φ10mm sheet blank;

[0044] (3) The above-mentioned blank is placed on a ceramic pad with dispersed zirconium dioxide pad material and fired. First, the binder is removed at 150°C for 30 minutes, and then the binder is removed at 600°C for 30 minutes. The heating rate is controlled at 5°C / min to raise the temperature to 1350°C and sinter for 1 hour to form ceramic. Finally, the ceramic is cooled to room temperature with the furnace to obtain capacitor ceramic material.

[0045] from Figure 1 It can be seen that the capacitor dielectric ceramic material prepared in this embodiment is densely sintered, with fine grains and a uniform particle size distribution. The room temperature dielectric constant of this ceramic material is 680, and the room temperature dielectric loss is 0.003. From... Figure 2 It can be seen that the temperature change rate of the dielectric constant is +1.5% to -14.3% in the range of -55℃ to +150℃, which meets the requirement of less than ±15% and meets the EIA X8R standard.

[0046] Example 3

[0047] The main crystalline phase powder of this ceramic material has the chemical formula: 0.78BaTiO3-0.22Bi[(Mg 2 / 3 Ta 1 / 3 ) 0.9967 Nb 0.0033 ]O 3.0033 x=0.22.

[0048] The composition of this ceramic material is shown in Table 3 below:

[0049] Table 3. Components and their contents in Example 3

[0050]

[0051] The preparation method of this ceramic material includes the following steps:

[0052] (1) Weigh BaCO3, Bi2O3, MgO, Ta2O5, Nb2O5 and TiO2 in a molar ratio of 0.78:0.11:0.1462:0.0365:0.000363:0.78, mix them to prepare the feedstock, and load the feedstock, agate grinding ball and deionized water into a ball mill jar at a mass ratio of 1:1.5:2.5. Wet ball milling is carried out for 6 hours to obtain a slurry. The slurry is then dried at 135℃ and calcined at 1080℃ for 2 hours at a rate of 5℃ / min to synthesize the main crystalline phase powder by solid-phase reaction.

[0053] (2) Add ZnO and MnO2 to the main crystalline phase powder according to the mass fraction in Table 3, and wet ball mill with agate grinding ball and deionized water at a mass ratio of 1:1.5:2.5 for 6 hours. Then dry at 135℃, add 4wt% polyvinyl alcohol (PVA) aqueous solution to granulate, pass through a 40-mesh sieve, and mold to obtain Φ10mm sheet blank.

[0054] (3) The above-mentioned blank is placed on a ceramic pad with dispersed zirconium dioxide pad material and fired. First, the binder is removed at 150°C for 30 minutes, and then the binder is removed at 600°C for 30 minutes. The heating rate is controlled at 5°C / min to raise the temperature to 1350°C and sinter for 1 hour to form ceramic. Finally, the ceramic is cooled to room temperature with the furnace to obtain capacitor ceramic material.

[0055] The capacitor dielectric ceramic material prepared in this embodiment is sintered densely, with a room temperature dielectric constant of 670, a room temperature dielectric loss of 0.0032, and a dielectric constant temperature change rate of +1.7% to -14.6% in the range of -55℃ to +150℃.

[0056] Example 4

[0057] The main crystalline phase powder of this ceramic material has the chemical formula: 0.82BaTiO3-0.18Bi[(Mg 2 / 3 Ta 1 / 3 ) 0.9973 Nb 0.0027 ]O 3.0027 x=0.18.

[0058] The composition of this ceramic material is shown in Table 4 below:

[0059] Table 4. Components and their contents in Example 4

[0060]

[0061] The preparation method of this ceramic material includes the following steps:

[0062] (1) Weigh BaCO3, Bi2O3, MgO, Ta2O5, Nb2O5 and TiO2 in a molar ratio of 0.82:0.09:0.119682:0.029925:0.000243:0.82, mix them to prepare the feedstock, and load the feedstock with agate grinding balls and deionized water in a mass ratio of 1:2:3 into a ball mill jar and perform wet ball milling for 4 hours to obtain a slurry; then dry the slurry at 135℃, raise it to 1050℃ at a rate of 6℃ / min and keep it at that temperature for 3 hours to synthesize the main crystalline phase powder by solid-phase reaction;

[0063] (2) Add ZnO and MnO2 to the main crystalline phase powder according to the mass fraction in Table 4, and wet ball mill with agate grinding ball and deionized water at a mass ratio of 1:1.5:2.5 for 4 hours. Then dry at 135℃, add 5wt% polyvinyl alcohol (PVA) aqueous solution to granulate, pass through a 40-mesh sieve, and mold to obtain Φ10mm sheet blank.

[0064] (3) The above-mentioned blank is placed on a ceramic pad with dispersed zirconium dioxide pad material and fired. First, the binder is removed at 200℃ for 35 minutes, and then the binder is removed at 550℃ for 25 minutes. The heating rate is controlled at 4℃ / min to raise the temperature to 1320℃ and sinter for 2 hours to form ceramic. Finally, the ceramic is cooled to room temperature with the furnace to obtain capacitor ceramic material.

[0065] The capacitor dielectric ceramic material prepared in this embodiment is sintered densely, with a room temperature dielectric constant of 870, a room temperature dielectric loss of 0.006, and a dielectric constant temperature change rate of +0.4% to -14.8% in the range of -55℃ to +150℃.

[0066] Example 5

[0067] The main crystalline phase powder of this ceramic material has the chemical formula: 0.82BaTiO3-0.18Bi[(Mg 2 / 3 Ta 1 / 3 ) 0.9973 Nb 0.0027 ]O 3.0027 x=0.18.

[0068] The composition of this ceramic material is shown in Table 5 below:

[0069] Table 5. Components and their contents in Example 5

[0070]

[0071] The preparation method of this ceramic material includes the following steps:

[0072] (1) Weigh BaCO3, Bi2O3, MgO, Ta2O5, Nb2O5 and TiO2 in a molar ratio of 0.82:0.09:0.119682:0.029925:0.000243:0.82, mix them to prepare the feedstock, and load the feedstock, agate grinding ball and deionized water into a ball mill jar in a mass ratio of 1:3:3.5. Wet ball milling is carried out for 5 hours to obtain a slurry. The slurry is then dried at 135°C and calcined at 1100°C at a rate of 4°C / min for 2.5 hours to synthesize the main crystalline phase powder by solid-phase reaction.

[0073] (2) Add ZnO and MnO2 to the main crystalline phase powder according to the mass fraction in Table 5, and wet ball mill with agate grinding ball and deionized water at a mass ratio of 1:3:3.5 for 5 hours. Then dry at 135℃, add 6wt% polyvinyl alcohol (PVA) aqueous solution to granulate, pass through a 40-mesh sieve, and mold to obtain Φ10mm sheet blank.

[0074] (3) The above-mentioned blank is placed on a ceramic pad with dispersed zirconium dioxide pad material and fired. First, the binder is removed at 250°C for 25 minutes, and then the binder is removed at 650°C for 35 minutes. The heating rate is controlled at 6°C / min to raise the temperature to 1360°C and sinter for 3 hours to form ceramic. Finally, the ceramic is cooled to room temperature with the furnace to obtain capacitor ceramic material.

[0075] The capacitor dielectric ceramic material prepared in this embodiment is sintered densely, with a room temperature dielectric constant of 850, a room temperature dielectric loss of 0.004, and a dielectric constant temperature change rate of +0.6% to -14.6% in the range of -55℃ to +150℃.

[0076] Comparative Example 1

[0077] The basic steps are the same as in Example 2, except that the value of x in the main crystalline phase powder is different; the chemical formula of the main crystalline phase powder of this ceramic material is: 0.9BaTiO3-0.1Bi[(Mg 2 / 3 Ta 1 / 3 ) 0.9985 Nb 0.0015 ]O 3.0015 x=0.1.

[0078] The capacitor dielectric ceramic material prepared in this embodiment is sintered densely. Although the room temperature dielectric constant is increased to 1591, the room temperature dielectric loss is as high as 0.015. The temperature change rate of the dielectric constant in the range of -55℃ to +150℃ is +0.4% to -25%.

[0079] Comparative Example 2

[0080] The basic steps are the same as in Example 2, except that the value of x in the main crystalline phase powder is different; the chemical formula of the main crystalline phase powder of this ceramic material is: 0.7BaTiO3-0.3Bi[(Mg2 / 3 Ta 1 / 3 ) 0.9955 Nb 0.0045 ]O 3.0045 x=0.3.

[0081] The capacitor dielectric ceramic material prepared in this embodiment is sintered densely, with a room temperature dielectric constant of 637 and a room temperature dielectric loss as high as 0.016. The temperature change rate of the dielectric constant in the range of -55℃ to +150℃ is +0.07% to -19%.

[0082] Comparative Example 3

[0083] The basic steps are the same as in Example 2, except that the sintering temperature in step (3) is different. Specifically, the heating rate is controlled at 5℃ / min to raise the temperature to 1150℃ and hold for 1 hour.

[0084] The capacitor dielectric ceramic material prepared in this embodiment is under-fired, with a room temperature dielectric constant of 838 and a room temperature dielectric loss as high as 0.01. The temperature change rate of the dielectric constant in the range of -55℃ to +150℃ is +0.007% to -17.7%.

[0085] Comparative Example 4

[0086] The basic steps are the same as in Example 2, except that Mg in the main crystalline phase powder is replaced with Zn, that is, the raw material MgO is replaced with ZnO; the chemical formula of the main crystalline phase powder of this ceramic material is: 0.8BaTiO3-0.2Bi[(Zn 2 / 3 Ta 1 / 3 ) 0.997 Nb 0.003 ]O 3.003 x=0.2.

[0087] The capacitor dielectric ceramic material prepared in this embodiment is sintered densely, with a room temperature dielectric constant of 899, a room temperature dielectric loss of 0.012, and a dielectric constant temperature change rate of -22.00 to +0.23℃ in the range of -55℃ to +150℃.

[0088] Comparative Example 5

[0089] The basic steps are the same as in Comparative Example 2, except that Mg in the main crystalline phase powder is replaced with Zn, that is, the raw material MgO is replaced with ZnO; the chemical formula of the main crystalline phase powder of this ceramic material is 0.7BaTiO3-0.3Bi[(Zn 2 / 3 Ta 1 / 3 ) 0.9955 Nb 0.0045 ]O 3.0045 x=0.3.

[0090] The capacitor dielectric ceramic material prepared in this embodiment is sintered densely, with a room temperature dielectric constant of 600, a room temperature dielectric loss of 0.038, and a dielectric constant temperature change rate of -26.33 to +11.43℃ in the range of -55℃ to +150℃.

[0091] Comparative Example 6

[0092] The basic steps are the same as in Example 1, except that Mg in the main crystalline phase powder is replaced with Zn, that is, the raw material MgO is replaced with ZnO; the chemical formula of the main crystalline phase powder of this ceramic material is: 0.82BaTiO3-0.18Bi[(Zn 2 / 3 Ta 1 / 3 ) 0.9973 Nb 0.0027 ]O 3.0027 x=0.18.

[0093] The capacitor dielectric ceramic material prepared in this embodiment is sintered densely, with a room temperature dielectric constant of 796, a room temperature dielectric loss of 0.013, and a dielectric constant temperature change rate of -21 to +1.25℃ in the range of -55℃ to +150℃.

Claims

1. An X8R capacitor dielectric porcelain material, characterized by, The following components are included by mass percentage: (1 -x)BaTiO3-xBi[(Mg 2 / 3 Ta 1 / 3 ) 1-0.015x Nb 0.015x ]O 3+0.015x 99.5-99.7wt% ZnO 0.15-0.25wt%; MnO2 0.15-0.25wt%; wherein x=0.18~0.

22.

2. A process for the preparation of the X8R capacitor dielectric porcelain mass according to claim 1, characterized in that, The following steps are included: (1) BaCO3, Bi2O3, MgO, Ta2O5, Nb2O5 and TiO2 are mixed in a molar ratio of (1-x):x / 2:2x(1-0.015x) / 3:x(1-0.015x) / 6:0.015x, and a main crystal phase powder is prepared by ball milling, drying and calcination 2 / 2:(1-x) (2) ZnO and MnO2 are added to the main crystal phase powder by mass percentage, and the green body is prepared by ball milling, drying, granulation and molding. The capacitor porcelain material is prepared by degumming and sintering.

3. The method of claim 2, wherein the X8R capacitor dielectric ceramic is prepared by the steps of: In step (2), the sintering is sintered in a buckled manner.

4. The method of claim 2, wherein the X8R capacitor dielectric ceramic is prepared by the steps of: In step (2), the sintering is sintered in a buckled manner at 1320~1360℃ for 1~3h.

5. The method of claim 2, wherein the X8R capacitor dielectric ceramic is prepared by the steps of: In step (2), the sintering rate is 4~6℃ / min.

6. The process for preparing X8R capacitor dielectric porcelain according to claim 2, characterized by, In steps (1) and (2), the ball milling is to mix and grind the ingredients, grinding balls and deionized water in a mass ratio of 1:1.5~3:2.5~3.5 for 4~6h.

7. The process for preparing X8R capacitor dielectric porcelain according to claim 2, characterized by, In step (1), the calcination is calcined at 1050℃~1100℃ for 2~3h.

8. The process for preparing X8R capacitor dielectric porcelain according to claim 2, characterized by, In step (1), the calcination rate is 4~6℃ / min.

9. The process for preparing X8R capacitor dielectric porcelain according to claim 2, characterized in that, In step (2), the granulation uses polyvinyl alcohol aqueous solution with a concentration of 4~6wt%.

10. The method for preparing the dielectric ceramic material of the X8R type capacitor according to claim 2, characterized in that: In step (2), the degumming is first heated at 150~250℃ for 25~35min, and then heated at 550~650℃ for 25~35min.

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