High-frequency high-stability C0G type MLCC medium powder material and solid-phase sintering preparation method and application thereof

Abstract

The invention relates to a high-frequency high-stability C0G type MLCC medium powder material and a solid-phase sintering preparation method and application thereof, and the solid-phase sintering preparation method comprises the following steps: mixing main material powder and auxiliary material powder, and sintering the obtained mixed powder; the main material powder is prepared from the following raw materials: calcium zirconate, strontium titanate and yttrium oxide in a molar ratio of 1: (0.95-1.65): (0.01-0.05); the auxiliary material powder is prepared from a barium source and a titanium source; the molar ratio of the main material powder to the auxiliary material powder is (20: 1)-(35: 1). According to the solid-phase sintering preparation method provided by the invention, the dielectric property and the temperature stability of the C0G type MLCC dielectric powder material can be improved only through simple raw material adjustment; in addition, the solid-phase sintering preparation method provided by the invention is simple and easy to implement, and the industrial scale production of the high-frequency and high-stability C0G type MLCC medium powder material can be realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic capacitors and relates to a ceramic material, and in particular to a high-frequency and high-stability C0G type MLCC dielectric powder material and a solid-phase sintering preparation method and application thereof. Background Art

[0002] With the rapid development of the mobile communication industry, electronic components are constantly developing in the direction of miniaturization, high performance and low cost, so multilayer ceramic capacitors (MLCC) came into being. Multilayer ceramic capacitors include dielectric materials and electrodes, and the current electrodes are mainly silver-palladium electrodes. However, with the increasing market demand for the fifth-generation mobile communication technology (5G), higher requirements are placed on electronic components, and the frequency of capacitors needs to be greatly increased.

[0003] C0G is a high-frequency, temperature-stable multilayer ceramic capacitor (MLCC), which belongs to Class I dielectric and is known for its ultra-low temperature coefficient and high stability. This type of capacitor performs well in scenarios with high temperature, high frequency and high reliability requirements, and is widely used in automotive electronics, aerospace, communication equipment and other fields. At present, the dielectric constant of ceramics used to prepare C0G ceramic capacitors is relatively small, generally not exceeding 100. Among the dielectric materials with a dielectric constant exceeding 100, one part is based on the bismuth-based pyrochlore system, but the pyrochlore material has high intrinsic dielectric loss and contains too much bismuth, which has the problem of element volatilization and alloying; the other part is based on the BaO-Ln2O3-TiO2 system (referred to as the BLT system) with a tungsten bronze structure. The system is mainly Ln2O3, Sm2O3, and Nd2O3. The reported dielectric constant can reach 80-90, and the temperature coefficient is <±30ppm / ℃, but the sintering temperature of BLT system ceramics is generally high (>1400℃), and densification sintering is difficult, which is not conducive to mass production. At present, the commonly used method is to select low-melting point glass or oxide as a sintering aid to achieve low-temperature dense sintering of ceramics, which results in a decrease in the dielectric constant of the ceramics, an increase in dielectric loss, and a change in the dielectric temperature characteristics.

[0004] Therefore, how to realize the industrialization of preparing high-frequency and high-stability C0G type MLCC dielectric powder materials by solid-phase sintering method is a technical problem that needs to be solved urgently. Summary of the invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a high-frequency and high-stability C0G type MLCC dielectric powder material, its solid-phase sintering preparation method and application. The solid-phase sintering preparation method can endow the high-frequency and high-stability C0G type MLCC dielectric powder material with a relatively high dielectric constant, low dielectric loss and high temperature stability, and is also conducive to realizing industrial-scale production.

[0006] To achieve the purpose of this invention, the following technical solutions are adopted:

[0007] In the first aspect, the present invention provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G type MLCC dielectric powder material, and the solid-phase sintering preparation method includes:

[0008] Mixing the main material powder and the auxiliary material powder, and subjecting the obtained mixed powder to sintering treatment to obtain the high-frequency and high-stability C0G type MLCC dielectric powder material;

[0009] The preparation raw materials of the main material powder include CaZrO3, SrTiO3 and Y2O3 with a molar ratio of 1:(0.95 - 1.65):(0.01 - 0.05);

[0010] The preparation raw materials of the auxiliary material powder are a barium source and a titanium source;

[0011] The molar ratio of Ba in the barium source to Ti in the titanium source is 0.990:1 to 1.010:1;

[0012] The molar ratio of the main material powder to the auxiliary material powder is 20:1 to 35:1.

[0013] The solid-phase sintering preparation method provided by the present invention can improve the dielectric properties and temperature stability of the high-frequency and high-stability C0G type MLCC dielectric powder material only by using simple auxiliary materials; moreover, the solid-phase sintering preparation method provided by the present invention is simple and easy to implement, and can realize the industrial-scale production of the high-frequency and high-stability C0G type MLCC dielectric powder material.

[0014] Preferably, the heating rate of the sintering treatment is 2 °C / min to 10 °C / min.

[0015] Preferably, the highest temperature of the sintering treatment is 1200 °C to 1480 °C.

[0016] Preferably, the holding time at the highest temperature of the sintering treatment is 0.5 h to 3 h.

[0017] Preferably, the preparation method of the auxiliary material powder includes: mixing the barium source and the titanium source according to the formula amount, drying and decarbonizing the mixed powder, and then performing auxiliary material crushing treatment to obtain the auxiliary material powder.

[0018] Preferably, the drying temperature is 80°C to 180°C, and the time is 6h to 18h.

[0019] Preferably, the carbon removal temperature is 450°C to 800°C, and the time is 8h to 18h.

[0020] Preferably, the preparation method of the main material powder includes: mixing CaZrO3, SrTiO3 and Y2O3 to obtain raw material powder; then performing pre-sintering treatment on the raw material powder to obtain a pre-sintered blank; and sequentially performing first crushing, grinding, carbon removal treatment and second crushing on the pre-sintered blank to obtain the main material powder.

[0021] Preferably, the median particle sizes of the CaZrO3, the SrTiO3 and the Y2O3 are independently 3μm to 15μm.

[0022] Preferably, the median particle size D50 of the main material powder is 0.8μm to 3.5μm.

[0023] Preferably, the heating rate of the pre-sintering is 5°C / min to 10°C / min.

[0024] Preferably, the highest temperature of the pre-sintering is 1150°C to 1350°C.

[0025] Preferably, the holding time at the highest temperature of the pre-sintering is 30min to 180min.

[0026] Preferably, the method of the first crushing includes deflocculation.

[0027] Preferably, the median particle size D50 of the powder after the first crushing is 0.8μm to 3.5μm.

[0028] Preferably, the method of the grinding includes sand grinding; the median particle size D50 of the powder obtained by the sand grinding is 0.6μm to 1.5μm.

[0029] Preferably, the carbon removal treatment includes: performing carbon removal at 450°C to 800°C for 8h to 18h.

[0030] Preferably, the carbon removal treatment further includes drying before carbon removal: drying at a temperature of 80°C to 180°C for 6h to 18h.

[0031] In a second aspect, the present invention provides a high-frequency and high-stability C0G type MLCC dielectric powder material, and the high-frequency and high-stability C0G type MLCC dielectric powder material is prepared by the solid-phase sintering preparation method described in the first aspect.

[0032] In a third aspect, the present invention provides a ceramic capacitor, which includes the high-frequency and high-stability C0G type MLCC dielectric powder material prepared by the solid-phase sintering preparation method described in the first aspect, or includes the high-frequency and high-stability C0G type MLCC dielectric powder material described in the second aspect.

[0033] The numerical ranges described in the present invention not only include the exemplified point values, but also include any point values between the above-mentioned numerical ranges that are not exemplified. Due to space limitations and for the sake of simplicity, the present invention does not exhaustively list the specific point values included in the described ranges.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The solid-phase sintering preparation method provided by the present invention can improve the dielectric properties and high-temperature resistance of the high-frequency and high-stability C0G type MLCC dielectric powder material only by using simple auxiliary materials; moreover, the solid-phase sintering preparation method provided by the present invention is simple and feasible, and can realize the industrial-scale production of the high-frequency and high-stability C0G type MLCC dielectric powder material. Description of the Drawings

[0036] Figure 1 SEM diagram of the high-frequency and high-stability C0G type MLCC dielectric powder material obtained in Example 1. Detailed Embodiments

[0037] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the described embodiments are only for helping to understand the present invention and should not be regarded as specific limitations to the present invention.

[0038] An embodiment of the present invention provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G type MLCC dielectric powder material, and the solid-phase sintering preparation method includes:

[0039] Mix the main material powder and the auxiliary material powder, and the obtained mixed powder is sintered to obtain the high-frequency and high-stability C0G type MLCC dielectric powder material;

[0040] The preparation raw materials of the main material powder include CaZrO3, SrTiO3 and Y2O3 with a molar ratio of 1:(0.95 - 1.65):(0.01 - 0.05);

[0041] The preparation raw materials of the auxiliary material powder are a barium source and a titanium source;

[0042] The molar ratio of Ba in the barium source to Ti in the titanium source is 0.990:1 to 1.010:1;

[0043] The molar ratio of the main material powder to the auxiliary material powder is 20:1 to 35:1. For example, it can be 20:1, 25:1, 27:1, 30:1, or 35:1, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0044] The molar ratio of CaZrO3 to SrTiO3 in the main material powder is 1:(0.95 - 1.65). For example, it can be 1:0.95, 1:1, 1:1.2, 1:1.4, 1:1.5, or 1:1.65, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0045] The molar ratio of CaZrO3 to Y2O3 in the main material powder is 1:(0.01 - 0.05). For example, it can be 1:0.01, 1:0.02, 1:0.03, 1:0.04, or 1:0.05, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0046] The solid-phase sintering preparation method provided by the present invention can improve the dielectric properties and temperature stability of the C0G-type MLCC dielectric powder material only by simply adjusting the components of the main material powder and the auxiliary material powder. Moreover, the solid-phase sintering preparation method provided by the present invention is simple and feasible, and can realize the industrial-scale production of high-frequency and high-stability C0G-type MLCC dielectric powder materials.

[0047] In some embodiments, the barium source includes barium carbonate and / or barium oxide.

[0048] In some embodiments, the titanium source includes titanium dioxide.

[0049] In some embodiments, the heating rate of the sintering treatment is 2°C / min to 10°C / min. For example, it can be 2°C / min, 4°C / min, 5°C / min, 6°C / min, 8°C / min, or 10°C / min, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0050] In some embodiments, the maximum temperature of the sintering treatment is 1200°C to 1480°C. For example, it can be 1200°C, 1250°C, 1300°C, 1350°C, 1400°C, 1450°C, or 1480°C, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0051] In some embodiments, the holding time at the maximum temperature of the sintering treatment is 0.5 h to 3 h. For example, it can be 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, or 3 h, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0052] In some embodiments, the method for preparing the auxiliary material powder includes: mixing a barium source and a titanium source according to a formulated amount, drying and carbon discharging the mixed powder, and then performing an auxiliary material crushing treatment to obtain the auxiliary material powder.

[0053] The solid-phase sintering preparation method provided by the present invention can make the particle size distribution of the obtained auxiliary material powder more concentrated by adopting a specific solid-phase sintering preparation method for the auxiliary material powder, so that the high-frequency and high-stability C0G type MLCC dielectric powder material has good dielectric properties and temperature stability.

[0054] The auxiliary material powder used in the present invention specifically selects a barium source and a titanium source in a specific ratio. When any one of the three auxiliary materials is missing, it cannot play the role of improving the dielectric properties and temperature stability of the C0G type MLCC dielectric powder material.

[0055] In the main material powder of the present invention, CaZrO3 is used as a basic framework material, and its dielectric constant is about 30-40; SrTiO3 has a relatively high dielectric constant but a too large temperature coefficient fluctuation; CaZrO3 can form a (Sr,Ca)ZrO3 solid solution structure with SrTiO3 to increase the dielectric constant of the C0G type MLCC dielectric powder material; the addition of Y2O3 can reduce the lattice constant, inhibit grain growth, reduce dielectric loss, and improve temperature stability.

[0056] In addition, in the auxiliary material powder of the present invention, the addition of Ba 2+ can form a solid solution with Ca 2+ , Sr 2+ to provide the low temperature coefficient characteristic of Ba to compensate for the positive temperature coefficient of SrTiO3; the addition of Ti 4+ can partially replace Zr 4+ and utilize its polarization ability to increase the dielectric constant.

[0057] The present invention can increase the dielectric constant and temperature stability of the C0G type MLCC dielectric powder material through the component composition of the main material powder and the auxiliary material powder; moreover, the solid-phase sintering preparation method is simple and easy to implement, and can realize the industrial-scale production of the high-frequency and high-stability C0G type MLCC dielectric powder material.

[0058] In some embodiments, the drying temperature is 80°C to 180°C (for example, it can be 80°C, 100°C, 120°C, 150°C, 160°C or 180°C, but not limited to the listed values), and the time is 6h to 18h (for example, it can be 6h, 8h, 10h, 12h, 15h, 16h or 18h, but not limited to the listed values).

[0059] In some embodiments, the temperature for carbon removal is 450°C to 800°C (for example, it can be 450°C, 500°C, 600°C, 700°C or 800°C, but not limited to the listed values), and the time is 8h to 18h (for example, it can be 8h, 10h, 12h, 15h, 16h or 18h, but not limited to the listed values).

[0060] In some embodiments, the method for preparing the main material powder includes: mixing CaZrO3, SrTiO3 and Y2O3 to obtain raw material powder; then performing pre-sintering treatment on the raw material powder to obtain a pre-sintered blank; and successively performing first crushing, grinding, carbon removal treatment and second crushing on the pre-sintered blank to obtain the main material powder.

[0061] The solid-phase sintering preparation method provided by the present invention can make the median particle size distribution of the obtained main material powder more concentrated by adopting a specific solid-phase sintering preparation method for the main material powder, so that the high-frequency and high-stability C0G type MLCC dielectric powder material has higher dielectric properties and temperature stability.

[0062] Among them, the pre-sintering treatment causes the titanium source and the barium source to undergo a solid-phase reaction and removes moisture, volatile impurities, gases and some organic substances existing inside the raw materials, thereby improving the purity of the obtained main material powder; in addition, the main material powder obtained by the pre-sintering treatment can better cooperate with the auxiliary material powder during subsequent sintering, thereby improving the dielectric properties and temperature stability of the C0G type MLCC dielectric powder material.

[0063] In some embodiments, the median particle sizes of the CaZrO3, the SrTiO3 and the Y2O3 are independently 3μm to 15μm, for example, it can be 3μm, 5μm, 8μm, 10μm, 12μm or 15μm, but not limited to the listed values, and the other unlisted values within the numerical range are equally applicable.

[0064] In some embodiments, the median particle size D50 of the main material powder is 0.8μm to 3.5μm, for example, it can be 0.8μm, 1μm, 1.5μm, 2μm, 2.5μm, 3μm or 3.5μm, but not limited to the listed values, and the other unlisted values within the numerical range are equally applicable.

[0065] In order to obtain a main material powder with a median particle size D50 satisfying 0.8μm to 3.5μm, the mixing of the CaZrO3, the SrTiO3 and the Y2O3 is first carried out in a three-dimensional mixer, and then a jet mill is used to obtain a main material powder with a median particle size D50 satisfying 0.8μm to 3.5μm.

[0066] In some embodiments, the heating rate of the pre-sintering is 5°C / min to 10°C / min. For example, it can be 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, or 10°C / min, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0067] In the present invention, the starting temperature of the pre-sintering is room temperature, for example, it can be 15°C to 30°C. For example, it can be 15°C, 18°C, 20°C, 25°C, 28°C, or 30°C, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0068] In some embodiments, the maximum temperature of the pre-sintering is 1150°C to 1350°C. For example, it can be 1150°C, 1120°C, 1125°C, 1130°C, or 1135°C, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0069] In some embodiments, the holding time at the maximum temperature during the pre-sintering is 30 min to 180 min. For example, it can be 30 min, 50 min, 80 min, 100 min, 120 min, 150 min, 160 min, or 180 min, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0070] In some embodiments, the method of the first crushing includes depolymerization.

[0071] Exemplarily, the depolymerization is carried out in a jet mill.

[0072] In some embodiments, the median particle size D50 of the powder after the first crushing is 0.8 μm to 3.5 μm. For example, it can be 0.8 μm, 1 μm, 1.5 μm, 2 μm, 2.5 μm, 3 μm, or 3.5 μm, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0073] In some embodiments, in order to obtain a powder with a median particle size D50 satisfying 0.8 μm to 3.5 μm by a jet mill and reduce the operating pressure of the jet mill, the first crushing includes sequentially performing coarse crushing by a jaw crusher, fine crushing by a roll crusher, and depolymerization by a jet mill. The "coarse crushing" and "fine crushing" herein are relative concepts, that is, the average median particle size of the material obtained by coarse crushing is larger than that of the material obtained by fine crushing.

[0074] In some embodiments, the method of the grinding includes sand grinding; the median particle size D50 of the powder obtained by the sand grinding is 0.6 μm to 1.5 μm.

[0075] The present invention does not specifically limit parameters such as the method and time of sanding. As long as the median particle size D50 of the powder obtained by sanding is 0.6 μm to 1.5 μm, generally speaking, by controlling the sanding time to be 30 min to 180 min, the technical effect that the median particle size D50 of the material obtained by sanding is 0.6 μm to 1.5 μm can be achieved.

[0076] Grinding can further refine the particle size of the main material powder. During the continuous refinement of its particle size, the specific surface area increases, which is beneficial to obtaining a dense high-frequency and high-stability C0G-type MLCC dielectric powder material in subsequent sintering. However, during the continuous refinement of the particle size, fine particles re-agglomerate under the influence of van der Waals force, double-layer electrostatic interaction, etc. Therefore, as a preferred technical solution, a dispersant is used during the grinding to prevent the aggregation of the main material powder. Therefore, carbon removal treatment needs to be carried out after grinding to remove the dispersant.

[0077] The present invention does not specifically limit the dosage and type of the dispersant, as long as the dispersion effect during grinding can be achieved.

[0078] In some embodiments, the carbon removal treatment includes: performing carbon removal at 450 °C to 800 °C for 8 h to 18 h.

[0079] The temperature of the carbon removal is 450 °C - 800 °C. For example, it can be 450 °C, 500 °C, 600 °C, 700 °C or 800 °C, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0080] The time of the carbon removal is 8 h to 18 h. For example, it can be 8 h, 10 h, 12 h, 15 h, 16 h or 18 h, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0081] In some embodiments, water is used as the sanding medium in the sanding. Water has a good dispersion effect. During the sanding process, it adsorbs on the surface of solid particles, reducing the interfacial tension between liquid-liquid and solid-liquid, making the surface of the aggregated solid particles easy to wet, and preventing the mutual aggregation of fine particles. However, the residual moisture is not conducive to subsequent sintering.

[0082] Preferably, the carbon removal treatment further includes drying before carbon removal: drying at a temperature of 80 °C to 180 °C for 6 h to 18 h.

[0083] The temperature of the drying is 80 °C to 180 °C. For example, it can be 80 °C, 100 °C, 120 °C, 150 °C, 160 °C or 180 °C, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0084] The drying time is 6h to 18h. For example, it can be 6h, 8h, 10h, 12h, 15h, 16h or 18h, but is not limited to the listed values. Other unlisted values within the numerical range are equally applicable.

[0085] An embodiment of the present invention provides a high-frequency and high-stability C0G type MLCC dielectric powder material, which is prepared by the solid-phase sintering preparation method described in any one of the embodiments.

[0086] The present invention provides a ceramic capacitor, which includes the high-frequency and high-stability C0G type MLCC dielectric powder material prepared by the solid-phase sintering preparation method described in any one of the embodiments, or includes the high-frequency and high-stability C0G type MLCC dielectric powder material described in any one of the embodiments.

[0087] To clearly illustrate the technical solution of the present invention, the normal temperature in the following specific embodiments is 25°C.

[0088] Example 1

[0089] This embodiment provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G type MLCC dielectric powder material, and the solid-phase sintering preparation method includes:

[0090] (1) Prepare the main material powder:

[0091] S11: Weigh CaZrO3 (median particle size D50 is 10μm), SrTiO3 (median particle size D50 is 10μm) and Y2O3 (median particle size D50 is 10μm) according to the molar ratio of 1:1.2:0.03, perform preliminary mixing in a three-dimensional mixer, and then crush and mix the mixed raw materials by an air-flow crusher to obtain raw material powder with a median particle size D50 of 2μm;

[0092] S12: Put the raw material powder into a crucible, vibrate and compact it on a compaction table to make the material fully dense, then punch out exhaust holes with a uniform honeycomb arrangement, and put it into a muffle furnace for pre-sintering; the initial temperature during pre-sintering is normal temperature, the highest temperature is 1200°C, the heating rate is 8°C / min, keep the temperature at the highest temperature for heat preservation, and the heat preservation time is 120min to obtain a pre-sintered blank;

[0093] S13: The pre-sintered blank is successively subjected to coarse crushing by a jaw crusher, fine crushing by a pair-roller machine and depolymerization by an air-flow crusher to obtain powder with a median particle size D50 of 2μm; then perform sanding treatment to reduce the median particle size D50 of the powder to 1μm;

[0094] S14: The powder after sanding is dried at 150 °C for 10 h, and then the carbon is removed at 600 °C for 12 h; then the powder after carbon removal is roughly crushed by a crusher and finely crushed by a roll crusher to obtain the main material powder;

[0095] (2) Preparation of auxiliary material powder:

[0096] S21: Weigh BaCO3 (median particle size D50 is 10 μm) and TiO2 (median particle size D50 is 10 μm) according to a molar ratio of 1:1, and mix them evenly in a ball mill;

[0097] S22: The mixed powder is dried at 150 °C for 10 h, and then the carbon is removed at 600 °C for 12 h; then the powder after carbon removal is roughly crushed by a crusher and finely crushed by a roll crusher to obtain the auxiliary material powder;

[0098] (3) Preparation of high-frequency and high-stability C0G-type MLCC dielectric powder material

[0099] S31: The main material powder obtained in step S14 and the auxiliary material powder obtained in step S24 are mixed in a jet mill in a way of depolymerization according to a molar ratio of 30:1 to obtain a mixed raw material powder;

[0100] S32: The raw material powder is filled into a crucible, vibrated and compacted on a vibrating table to make the material fully dense, and then exhaust holes arranged in a uniform honeycomb pattern are punched out and put into a muffle furnace for sintering treatment; the initial temperature during sintering treatment is room temperature, the highest temperature is 1400 °C, the heating rate is 8 °C / min, and insulation is carried out when the highest temperature is reached, and the insulation time is 2 h. The obtained material is successively roughly crushed by a jaw crusher, finely crushed by a roll crusher and depolymerized by a jet mill to obtain a high-frequency and high-stability C0G-type MLCC dielectric powder material with a median particle size D50 of 1 μm, and its SEM image is as Figure 1 shown.

[0101] Example 2

[0102] This example provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G-type MLCC dielectric powder material, and the solid-phase sintering preparation method includes:

[0103] (1) Preparation of main material powder:

[0104] S11: Weigh CaZrO3 (median particle size D50 is 3 μm), SrTiO3 (median particle size D50 is 3 μm) and Y2O3 (median particle size D50 is 3 μm) according to a molar ratio of 1:0.95:0.01, carry out preliminary mixing in a three-dimensional mixer, and then crush and mix the mixed raw materials by a jet mill to obtain a raw material powder with a median particle size D50 of 0.8 μm;

[0105] S12: The raw material powder is filled into a sagger, vibrated and compacted on a vibrating table to make the material fully dense, then exhaust holes arranged in a uniform honeycomb pattern are punched out, and it is put into a muffle furnace for pre-sintering; the initial temperature during pre-sintering is room temperature, the maximum temperature is 1150 °C, the heating rate is 5 °C / min, it is heated to the maximum temperature and then held for 180 min to obtain a pre-sintered blank;

[0106] S13: The pre-sintered blank is successively subjected to coarse crushing by a jaw crusher, fine crushing by a pair-roller machine and depolymerization by an air-flow pulverizer to obtain powder with a median particle size D50 of 0.8 μm; then it is subjected to sanding treatment to reduce the median particle size D50 of the powder to 0.6 μm;

[0107] S14: The sanded powder is dried at 80 °C for 18 h, and then degassed at 450 °C for 18 h; then the degassed powder is subjected to coarse crushing by a crusher and fine crushing by a pair-roller machine to obtain the main material powder;

[0108] (2) Preparation of auxiliary material powder:

[0109] S21: BaCO3 (median particle size D50 is 3 μm) and TiO2 (median particle size D50 is 3 μm) are weighed according to a molar ratio of 0.990:1 and mixed evenly in a ball mill;

[0110] S22: The evenly mixed powder is dried at 80 °C for 18 h, and then degassed at 450 °C for 18 h; then the degassed powder is subjected to coarse crushing by a crusher and fine crushing by a pair-roller machine to obtain the auxiliary material powder;

[0111] (3) Preparation of high-frequency and high-stability C0G type MLCC dielectric powder material

[0112] S31: The main material powder obtained in step S14 and the auxiliary material powder obtained in step S24 are mixed in an air-flow pulverizer in a depolymerization manner according to a molar ratio of 20:1 to obtain a mixed raw material powder;

[0113] S32: The raw material powder is filled into a sagger, vibrated and compacted on a vibrating table to make the material fully dense, then exhaust holes arranged in a uniform honeycomb pattern are punched out, and it is put into a muffle furnace for sintering treatment; the initial temperature during sintering treatment is room temperature, the maximum temperature is 1200 °C, the heating rate is 2 °C / min, it is heated to the maximum temperature and then held for 3 h, and the obtained material is successively subjected to coarse crushing by a jaw crusher, fine crushing by a pair-roller machine and depolymerization by an air-flow pulverizer to obtain a high-frequency and high-stability C0G type MLCC dielectric powder material with a median particle size D50 of 1 μm.

[0114] Example 3

[0115] This embodiment provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G-type MLCC dielectric powder material, and the solid-phase sintering preparation method includes:

[0116] (1) Prepare the main material powder:

[0117] S11: Weigh CaZrO3 (median particle size D50 is 15 μm), SrTiO3 (median particle size D50 is 15 μm), and Y2O3 (median particle size D50 is 15 μm) according to the molar ratio of 1:1.65:0.05, perform preliminary mixing in a three-dimensional mixer, and then crush and mix the mixed raw materials through an air-flow crusher to obtain raw material powder with a median particle size D50 of 3.5 μm;

[0118] S12: Load the raw material powder into a sagger, vibrate and compact it on a compaction table to make the material fully dense, then punch out exhaust ports with a uniform honeycomb arrangement, and place it in a muffle furnace for pre-sintering; the initial temperature during pre-sintering is room temperature, the highest temperature is 1350 °C, the heating rate is 10 °C / min, keep the temperature at the highest temperature for heat preservation, and the heat preservation time is 30 min to obtain a pre-sintered blank;

[0119] S13: The pre-sintered blank is successively subjected to coarse crushing by a jaw crusher, fine crushing by a pair-roll crusher, and deflocculation by an air-flow crusher to obtain powder with a median particle size D50 of 3.5 μm; then perform sanding treatment to reduce the median particle size D50 of the powder to 1.5 μm;

[0120] S14: The sanded powder is dried at 180 °C for 6 h, and then degassed at 800 °C for 8 h; then the degassed powder is subjected to coarse crushing by a crusher and fine crushing by a pair-roll crusher to obtain the main material powder;

[0121] (2) Prepare the auxiliary material powder:

[0122] S21: Weigh BaCO3 (median particle size D50 is 15 μm) and TiO2 (median particle size D50 is 15 μm) according to the molar ratio of 1.010:1, and mix them evenly in a ball mill;

[0123] S22: The evenly mixed powder is dried at 180 °C for 6 h, and then degassed at 800 °C for 8 h; then the degassed powder is subjected to coarse crushing by a crusher and fine crushing by a pair-roll crusher to obtain the auxiliary material powder;

[0124] (3) Prepare the high-frequency and high-stability C0G-type MLCC dielectric powder material

[0125] S31: The main material powder obtained in step S14 and the auxiliary material powder obtained in step S24 are mixed in a deflocculation manner in an air-flow crusher according to the molar ratio of 35:1 to obtain a mixed raw material powder;

[0126] S32: The raw material powder is filled into a sagger, vibrated and compacted on a vibration compactor to make the material fully dense. Then, exhaust ports arranged in a uniform honeycomb pattern are punched out, and the sagger is placed in a muffle furnace for sintering. During the sintering process, the initial temperature is room temperature, the maximum temperature is 1480 °C, and the heating rate is 10 °C / min. When the maximum temperature is reached, heat preservation is carried out for 0.5 h. The obtained material is successively subjected to coarse crushing by a jaw crusher, fine crushing by a pair-roller crusher, and depolymerization by a jet mill to obtain a high-frequency and high-stability C0G-type MLCC dielectric powder material with a median particle size D50 of 1 μm.

[0127] Example 4

[0128] This example provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G-type MLCC dielectric powder material, which is the same as Example 1 except that the carbon removal temperature in step S14 is 400 °C.

[0129] Example 5

[0130] This example provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G-type MLCC dielectric powder material, which is the same as Example 1 except that the carbon removal temperature in step S14 is 850 °C.

[0131] Example 6

[0132] This example provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G-type MLCC dielectric powder material, which is the same as Example 1 except that step S14 is not carried out.

[0133] Example 7

[0134] This example provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G-type MLCC dielectric powder material, which is the same as Example 1 except that the carbon removal temperature in step S22 is 400 °C.

[0135] Example 8

[0136] This example provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G-type MLCC dielectric powder material, which is the same as Example 1 except that the carbon removal temperature in step S22 is 850 °C.

[0137] Example 9

[0138] This example provides a solid-phase sintering preparation method for a high-frequency and high-stability C0G-type MLCC dielectric powder material, which is the same as Example 1 except that step S22 is not carried out.

[0139] Comparative Example 1

[0140] This comparative example provides a solid-phase sintering preparation method for a C0G-type MLCC dielectric powder material. Except for not performing the sanding in step S13, the rest are the same as in Example 1.

[0141] Comparative Example 2

[0142] This comparative example provides a solid-phase sintering preparation method for a C0G-type MLCC dielectric powder material. Except that the preparation raw material of the auxiliary powder is only BaCO3, the rest are the same as in Example 1.

[0143] Comparative Example 3

[0144] This comparative example provides a solid-phase sintering preparation method for a C0G-type MLCC dielectric powder material. Except that the preparation raw material of the auxiliary powder is only TiO2, the rest are the same as in Example 1.

[0145] Comparative Example 4

[0146] This comparative example provides a solid-phase sintering preparation method for a C0G-type MLCC dielectric powder material. Except that the preparation raw materials of the main powder are CaZrO3 and SrTiO3 with a molar ratio of 1:1.2, the rest are the same as in Example 1.

[0147] Comparative Example 5

[0148] This comparative example provides a solid-phase sintering preparation method for a C0G-type MLCC dielectric powder material. Except that the preparation raw materials of the main powder are CaZrO3 and Y2O3 with a molar ratio of 1:0.03, the rest are the same as in Example 1.

[0149] Comparative Example 6

[0150] This comparative example provides a solid-phase sintering preparation method for a C0G-type MLCC dielectric powder material. Except that the preparation raw materials of the main powder are SrTiO3 and Y2O3 with a molar ratio of 1.2:0.03, the rest are the same as in Example 1.

[0151] Comparative Example 7

[0152] This comparative example provides a solid-phase sintering preparation method for a C0G-type MLCC dielectric powder material. Except that the molar ratio of the main powder to the auxiliary powder is 1:30, the rest are the same as in Example 1.

[0153] Performance Characterization

[0154] The C0G type MLCC dielectric powder materials obtained in the above-mentioned examples and comparative examples were pressed into disc samples with a diameter of 30 mm and a thickness of 4 mm under a pressure of 20 MPa. The relative dielectric constant, dielectric loss tanδ, insulation resistance, and breakdown voltage of the disc samples were measured in the temperature range of -55°C to 150°C. The results are shown in Tables 1 to 3.

[0155] Table 1

[0156]

[0157]

[0158] Table 2

[0159]

[0160]

[0161] Table 3

[0162]

[0163]

[0164] In summary, the solid-phase sintering preparation method provided by the present invention can improve the dielectric properties and temperature stability of the C0G type MLCC dielectric powder materials only by simple raw material adjustment; moreover, the solid-phase sintering preparation method provided by the present invention is simple and feasible, and can realize the industrial-scale production of high-frequency and high-stability C0G type MLCC dielectric powder materials.

[0165] The applicant declares that the above description is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A solid-phase sintering preparation method for a high-frequency and high-stability C0G type MLCC dielectric powder material, characterized in that, The solid-phase sintering preparation method includes: Mixing the main material powder and the auxiliary material powder, and subjecting the obtained mixed powder to sintering treatment to obtain the high-frequency and high-stability C0G type MLCC dielectric powder material; The raw materials for preparing the main material powder include CaZrO3, SrTiO3 and Y2O3 with a molar ratio of 1:(0.95 - 1.65):(0.01 - 0.05); The raw materials for preparing the auxiliary material powder are a barium source and a titanium source; The molar ratio of Ba in the barium source to Ti in the titanium source is 0.990:1 to 1.010:1; The molar ratio of the main material powder to the auxiliary material powder is 20:1 to 35:

1.

2. The solid-phase sintering preparation method according to claim 1, characterized in that The heating rate of the sintering treatment is 2°C / min to 10°C / min; and / or, the highest temperature of the sintering treatment is 1200°C to 1480°C; and / or, the holding time at the highest temperature of the sintering treatment is 0.5 h to 3 h.

3. The solid-phase sintering preparation method according to claim 1, wherein The preparation method of the auxiliary material powder includes: mixing the barium source and the titanium source according to the formula amount, drying and carbon removal of the mixed powder, and then performing auxiliary material crushing treatment to obtain the auxiliary material powder.

4. The solid-phase sintering preparation method according to claim 3, wherein The temperature of the drying is 80°C to 180°C, and the time is 6 h to 18 h; and / or, the temperature of the carbon removal is 450°C to 800°C, and the time is 8 h to 18 h.

5. The solid-phase sintering preparation method according to claim 1, wherein, The preparation method of the main material powder includes: mixing CaZrO3, SrTiO3 and Y2O3 to obtain a raw material powder; then subjecting the raw material powder to pre-sintering treatment to obtain a pre-sintered blank; the pre-sintered blank is successively subjected to first crushing, grinding, carbon removal treatment and second crushing to obtain the main material powder.

6. The solid-phase sintering preparation method according to claim 5, characterized in that The median particle sizes of the CaZrO3, the SrTiO3 and the Y2O3 are independently 3 μm - 15 μm; and / or, the median particle size D50 of the main material powder is 0.8 μm - 3.5 μm.

7. The solid-phase sintering preparation method according to claim 5, characterized in that The heating rate of the pre-sintering is 5°C / min to 10°C / min; and / or, the highest temperature of the pre-sintering is 1150°C to 1350°C; and / or, the holding time at the highest temperature of the pre-sintering is 30 min to 180 min; and / or, the method of the first crushing includes deflocculation; and / or, the median particle size D50 of the powder after the first crushing is 0.8 μm - 3.5 μm.

8. The solid-phase sintering preparation method according to claim 5, characterized in that, The method of the grinding includes sand grinding; the median particle size D50 of the powder obtained by the sand grinding is 0.6 μm - 1.5 μm. and / or, the carbon removal treatment includes: performing carbon removal at 450°C to 800°C for 8 h to 18 h; and / or, the carbon removal treatment further includes drying before carbon removal: drying at a temperature of 80°C to 180°C for 6 h to 18 h.

9. A high-frequency and high-stability C0G type MLCC dielectric powder material, characterized in that, The high-frequency and high-stability C0G type MLCC dielectric powder material is prepared by the solid-phase sintering preparation method according to any one of claims 1 to 8.

10. A ceramic capacitor, characterized in that, The ceramic capacitor includes the high-frequency and high-stability C0G type MLCC dielectric powder material prepared by the solid-phase sintering preparation method according to any one of claims 1 to 8, or includes the high-frequency and high-stability C0G type MLCC dielectric powder material according to claim 9.

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