TWI815177B - A low-temperature co-fired ceramic material and slurry, green ceramic tape, microwave dielectric ceramic device and use for preparing microwave dielectric ceramic device - Google Patents

Abstract

The invention discloses a low-temperature co-fired ceramic material, which includes a matrix component. The matrix component includes: BaTi ₄ O ₉ 55-70wt%; Mg ₂ SiO ₄ 5-15wt%; Zn-B-Si-Al low melting point Glass powder 15-30wt%. This low-temperature co-fired ceramic material can meet the use requirements of Sub-6GHz microwave devices. It has a dielectric constant of 18-22, a high quality factor, a near-zero resonant frequency temperature coefficient, a sintering temperature of 850-900°C, and with temperature The stability of changes becomes better and can be used to make RF front-end filters, duplexers, etc. for 5G communication base stations, which has important application prospects.

Description

A low-temperature co-fired ceramic material and slurry, green ceramic tape, and microwave dielectric ceramics Devices and uses for preparing microwave dielectric ceramic devices

The invention belongs to the technical field of low-temperature co-fired ceramic materials, and specifically relates to a ceramic material with high porcelain density, medium dielectric constant, low dielectric loss, and near-zero resonant frequency coefficient and a preparation method thereof. This ceramic material can be used to make dielectric filters, dielectric antennas, duplexers and other components in the field of electronic communications.

Low Temperature Co-fired Ceramics (LTCC) technology is to make low-temperature sinterable ceramic powder into a green porcelain tape with precise thickness and density, and then perform laser drilling and microporous grouting on the green porcelain tape. , precision conductor paste printing and other processes to produce the required circuit patterns, and bury multiple passive components (such as transformers (T), resistors (R), inductors (L), capacitors (C), etc.) into them , and then laminated and sintered to achieve miniaturization, lightweight, high performance and multi-functional design of electronic components and packaging modules. In practical applications, since LTCC ceramic materials need to be co-fired with low melting point electrode materials, the sintering temperature is generally required to be lower than 900°C.

The dielectric constant of BaTi ₄ O ₉ microwave material is 37 and has a high quality factor, but it has an excessively high sintering temperature (1200-1250°C). In addition, materials with a dielectric constant of 37 are rarely used in the currently commonly used microwave frequency bands. This greatly limits the application of BaTi ₄ O ₉ in the field of low-temperature co-firing.

In order to solve the above problems, the technical means generally adopted in the prior art is to add low melting point glass powder to the BaTi ₄ O ₉ material. The low melting point glass powder usually also has the characteristics of low dielectric constant and is easy to be sintered at low temperature. By adding low melting point glass powder to the BaTi ₄ O ₉ material, not only can the sintering temperature of the BaTi ₄ O ₉ material be reduced, but the dielectric constant can also be adjusted so that it can be used in the currently commonly used microwave frequency band.

However, the above technical means still have shortcomings. Generally speaking, there are three important indicators to evaluate the dielectric properties of microwave dielectric ceramic materials: dielectric constant, dielectric loss, and resonant frequency temperature coefficient. Although the glass-ceramic composite material formed by BaTi ₄ O ₉ and low melting point glass has a suitable dielectric constant and low dielectric loss, its application is limited due to the high temperature coefficient of the resonant frequency.

Therefore, a new low-temperature co-fired ceramic material and its preparation method are urgently needed to solve the above technical problems.

In order to solve the above technical problems, the present invention provides a new low-temperature co-fired ceramic material. The low-temperature co-fired ceramic material has a suitable dielectric constant and good low-temperature sintering performance, and is suitable for application in the fields of microwave dielectric filters, dielectric antennas, duplexers and other components.

A low-temperature co-fired ceramic material according to the present invention includes a matrix component, and the matrix component includes the following components in terms of mass content:

Wherein, the low melting point glass powder includes the following components in parts by weight:

Wherein, the low melting point glass powder further includes: BaO 0-5 parts by weight; Li ₂ O 0-5 parts by weight.

Wherein, the low-temperature co-fired ceramic material further includes additives, and the content of the additives is 0.5-5wt% of the total mass of the matrix component.

Wherein, the additive includes one or more selected from oxides or carbonates of B, Zn, Cu or Li. The additive has a burning-promoting effect.

The invention also discloses a method for preparing low-temperature co-fired ceramic materials as described above, which includes the following steps: (1) Take selected amounts of BaTi ₄ O ₉ , Mg ₂ SiO ₄ , low melting point glass powder and additives, and mix them together Obtain the first material, add water and organic additives to the first material and mix to obtain the first mixture, and then perform dispersion treatment on the mixture to obtain the second material; (2) Dry the second material, and dry the The resulting powder is sieved to obtain the low-temperature co-fired ceramic material.

Wherein, in the step (1), the mixing is ball milling and the dispersing is sand milling.

Wherein, in the step (1), the specific surface area of the dispersed material is controlled to be 4-6m ² /g.

Wherein, in the step (1), the mass ratio of the first material and water is controlled to be 1:1-1.5.

Wherein, in the step (1), the organic additive is a dispersant, and the added amount of the dispersant is 0.2-1.0wt% of the first material amount.

Wherein, in the step (1), in the ball milling step, the solid content in the first mixture is controlled to be 35-40wt%.

Wherein, in the step (2), the drying is spray drying.

Wherein, in the step (2), a spray dryer is used for spray drying, and the inlet temperature of the spray dryer is controlled to 250±5°C, the outlet temperature is 120±5°C, and the atomizer rotation speed is 10800±50r/min.

Wherein, the method for preparing low-temperature co-fired ceramic materials as described above further includes: performing one or more of the following steps (i), step (ii), and step (iii) before step (1): (i) The steps of obtaining BaTi ₄ O ₉ ; (ii) the steps of obtaining Mg ₂ SiO ₄ ; (iii) the steps of obtaining low melting point glass powder.

Wherein, the step (i) is to prepare BaTi ₄ O ₉ through a solid-phase synthesis method, which includes the following steps: weigh BaCO ₃ and TiO ₂ according to the stoichiometric ratio and mix them to obtain a second mixture; and add water and dispersant Pre-mix and disperse by ball milling, and perform sand grinding and re-dispersion treatment; then spray-dry the dispersed materials, and calcine the dried powder at 1050±50°C, with a holding time of 4 hours, and then add the calcined powder to Water is added to the body for ball milling and sand dispersion treatment, and then the dispersed material is spray-dried to obtain the required BaTi ₄ O ₉ material.

Wherein, in the step (i), the stoichiometric ratio of the BaCO ₃ and TiO ₂ is 1:4; the mass ratio of the second mixture and water is controlled to be 1:1-1.5; the dispersant The added amount accounts for 0.2-1.0wt% of the second mixed material; the dispersant includes an ammonium salt dispersant; the particle size D50 of the sand-ground material is controlled within the range of 0.5-0.9 μm, and the spray The drying step controls the moisture content of the material to <0.5wt%.

Wherein, the step (ii) is a step of preparing Mg ₂ SiO ₄ through a solid-phase synthesis method, which includes the following steps: weigh Mg(OH) ₂ and SiO ₂ according to the stoichiometric ratio and mix them to obtain a third mixture; and add Water and dispersant are premixed and dispersed by ball milling, and then sand milled and redispersed; then the dispersed material is spray-dried, and the dried powder is calcined at 1200±10°C with a holding time of 2-4h. Then add water to the calcined powder for ball milling, sand grinding and re-dispersion, and then spray-dry the dispersed material to obtain the required Mg ₂ SiO ₄ material.

Wherein, in the step (ii), the stoichiometric ratio of Mg(OH) ₂ :SiO ₂ is 2:1; the mass ratio of the third mixture and water is controlled to be 1:0.5-1.5; The added amount of the dispersant accounts for 1.0-1.5wt% of the third mixed material; the dispersant includes an ammonium salt dispersant; the particle size D50 of the sand-ground material is controlled at 0.4-0.8 μm. The spray drying step controls the moisture content of the material to <0.5wt%.

Wherein, the step (iii) is the step of preparing low melting point glass powder, which includes the following steps: weigh the corresponding raw materials according to the glass components, mix them evenly, and perform melting, quenching, crushing, and drying to obtain the required low melting point Glass powder.

The invention provides a low-temperature co-fired ceramic slurry, which includes the above-mentioned low-temperature co-fired ceramic material and organic additives.

Wherein, the organic auxiliary agent includes one or more of dispersant, defoaming agent, binder, plasticizer or dissolving agent.

The present invention also provides a method for preparing the above-mentioned low-temperature co-fired ceramic slurry, which includes adding organic additives to the above-mentioned low-temperature co-fired ceramic material and mixing evenly.

The present invention also provides a green ceramic belt, which includes the sintered low-temperature co-fired ceramic material or the sintered low-temperature co-fired ceramic slurry.

The present invention also provides a method for preparing the above-mentioned green porcelain tape, which includes making the above-mentioned low-temperature co-fired ceramic material into a green body, or the above-mentioned low-temperature co-fired ceramic slurry into a green body, and placing the green body at 850-900 °C for thermal insulation sintering.

The present invention also provides the use of the low-temperature co-fired ceramic material, the low-temperature co-fired ceramic slurry or the above-mentioned green ceramic tape for preparing microwave dielectric ceramic devices.

The present invention also provides a microwave dielectric ceramic device, which includes the sintered low-temperature co-fired ceramic material, or the sintered low-temperature co-fired ceramic slurry, or the green ceramic tape.

The invention also provides a method for preparing a microwave dielectric ceramic device, which includes the steps of making the low-temperature co-fired ceramic material into a green body or the low-temperature co-fired ceramic slurry into a green body, and converting the green body into a green body. The heat preservation and sintering step is performed at 850-900°C.

The beneficial technical effects of the present invention are reflected in the following aspects:

1. The low-temperature co-fired ceramic material of the present invention is prepared by using BaTi ₄ O ₉ , Mg ₂ SiO ₄ and low melting point glass powder as raw materials, and adding oxides and/or carbonates with a sintering-assisting effect as additives. Among them, BaTi ₄ O ₉ is used as the basic material, with a dielectric constant of about 37, f*Q=40000, and a resonant frequency temperature coefficient of +20ppm/℃. The addition of low-melting glass powder and additives can effectively reduce the sintering temperature of the material and appropriately adjust the microwave performance of the material, so that the sintering temperature of the BaTi ₄ O ₉ -based low-temperature co-fired ceramic material can be reduced from 1250°C to 850-850°C. 900℃, which greatly improves the low-temperature sintering performance of the material and is more conducive to industrial production.

2. Mg ₂ SiO ₄ is a material with an olivine structure formed by Si-O tetrahedrons and Mg-O tetrahedrons linked through a co-top and co-edge framework, in which the Si-O bond consists of 55% covalent Composed of bonds and 45% ionic bonds, the high content of covalent bonds makes Mg ₂ SiO ₄ have a low dielectric constant (6.8) and low dielectric loss, while the resonant frequency temperature coefficient τ _f is about -68ppm/℃. Therefore, the addition of Mg ₂ SiO ₄ material with negative temperature coefficient helps to move the temperature coefficient of the resonant frequency of the material to the negative direction and gradually approaches zero. Adding Mg ₂ SiO ₄ to the composite material of BaTi ₄ O ₉ and glass can effectively reduce its resonant frequency temperature coefficient.

3. The glass powder used in the present invention needs to be Zn-B-Si-Al low-melting glass powder. During the low-temperature sintering process, the BaO-TiO ₂ ceramic system reacts chemically with the boron-containing low-burning additive to form a new phase, that is, the sintering additive. The agent melts into a liquid phase coating the BaTi ₄ O ₉ grains.

4. The composite of BaTi ₄ O ₉ , Mg ₂ SiO ₄ and Zn-B-Si-Al low-melting point glass powder can combine the advantages of the three materials to obtain a low-temperature co-fired ceramic material that meets the requirements of Sub-6GHz microwave devices. . This low-temperature co-fired ceramic material has a dielectric constant of 18-22, a high quality factor, a near-zero resonant frequency temperature coefficient, a sintering temperature of 850-900°C, and its stability becomes better with temperature changes, and can be used to make composite materials. 5G communication base station radio frequency front-end filters, duplexers, etc. have important application prospects.

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.

Example 1

其中，所述低熔點玻璃粉包括如下重量份的組分：

The low-temperature co-fired ceramic material in this embodiment includes the following mass content components based on the total amount of raw materials for its preparation:

Wherein, the low melting point glass powder includes the following components by weight:

The preparation method of low-temperature co-fired ceramic materials described in this embodiment includes the following steps: (1) According to the selected stoichiometric ratio, weigh the corresponding weights of BaCO ₃ and TiO ₂ and add water (material: water = 1:1.2) Mix evenly with ammonium acrylate dispersant (accounting for 0.7wt% of the powder), use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion , to obtain a uniformly dispersed slurry; (2) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 1%, and use the solid-phase method to dry the dried powder in a calcining furnace at 1050°C. Calcination, holding time 4h, obtain BaTi ₄ O ₉ for later use; the reaction equation is: BaCO ₃ +4 TiO ₂ →BaTi ₄ O ₉ +CO ₂ ↑

(3) According to the selected stoichiometric ratio, weigh the corresponding weight of Mg(OH) ₂ and SiO ₂ , add water (material: water = 1:1.5) and ammonium acrylate dispersant (accounting for 1wt% of the powder amount) ) and mix evenly, use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion to obtain a uniformly dispersed slurry; (4) Disperse the dispersed slurry Use a spray dryer to dry the material until the moisture content is less than 1%, and use the solid-phase reaction method to calcine the dried powder in a calcining furnace at 1190°C with a holding time of 3 hours to obtain Mg ₂ SiO ₄ for later use; The reaction equation is: Mg(OH) ₂ +SiO ₂ →Mg ₂ SiO ₄ +2H ₂ O

(5) According to the selected mass content ratio, mix the ZnO, SiO ₂ , B ₂ O ₃ and Al ₂ O ₃ evenly, and perform melting treatment at 1300°C. After the molten glass is cooled, use a roller machine Crush, and then grind with a dry ball mill and a jet pulverizer. The particle size after grinding is required to be less than 2 μm to obtain the required low melting point glass powder for later use; (6) Take the selected content of the glass powder and step (2) , BaTi ₄ O ₉ and Mg ₂ SiO ₄ of (4), add water (material: water = 1:0.4) and ammonium acrylate dispersant (accounting for 0.8wt% of the mixture), mix well, and use a ball mill for pre-treatment After mixing and dispersion, the initially dispersed slurry is re-dispersed using a horizontal sand mill to obtain a sand-ground mixed slurry. Then use a spray dryer to carry out spray drying. The inlet temperature is 250±5°C and the outlet temperature is 120±5°C. The spray-dried powder is passed through an 80-mesh sieve to obtain the required low-temperature co-fired ceramic material.

The screened low-temperature co-fired ceramic material powder was pressed into discs using a tablet press, and the pressed discs were heat-insulated and sintered at 900°C for 4 hours for microwave dielectric property testing.

Example 2

其中，所述低熔點玻璃粉包括如下重量份的組分：

The low-temperature co-fired ceramic material in this embodiment includes the following mass content components based on the total amount of raw materials for its preparation:

Wherein, the low melting point glass powder includes the following components by weight:

The preparation method of BaTi ₄ O _9- based low-temperature co-fired ceramic materials described in this embodiment includes the following steps: (1) According to the selected stoichiometric ratio, weigh the corresponding weights of BaCO ₃ and TiO ₂ and add water (material: water =1:1.2) and ammonium acrylate dispersant (accounting for 0.8wt% of the powder), mix evenly, use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium ball) for further dispersion to obtain a uniformly dispersed slurry; (2) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 1%, and use a calciner to dry the dried powder at 1070°C Calculate and hold for 4 hours to obtain BaTi ₄ O ₉ for later use; (3) According to the selected stoichiometric ratio, weigh the corresponding weight of Mg(OH) ₂ and SiO ₂ and add water (material: water = 1:1.5) and Ammonium acrylate dispersant (accounting for 1wt% of the powder) was mixed, and a ball mill was used for premixing for 3 hours. After ball milling, a horizontal sand mill (the grinding medium used 0.65mm zirconium balls) was used for further dispersion to obtain Uniformly dispersed slurry; (4) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 0.5%, and use a calcining furnace to calcine the dried powder at 1200°C for 3 hours to obtain Mg ₂ SiO ₄ , for later use; (5) According to the selected mass content ratio, mix the ZnO, SiO ₂ , B ₂ O ₃ and Al ₂ O ₃ evenly, and perform melting treatment at 1350°C. The molten glass is After cooling, use a roller machine to pulverize. After pulverization, use a dry ball mill and a jet pulverizer to grind. The particle size after grinding is required to be less than 2 μm to obtain the required low melting point glass powder for later use; (6) Take the selected content of the above-mentioned glass powder. Glass powder, BaTi ₄ O ₉ and Mg ₂ SiO ₄ from steps (2) and (4), add water (material: water = 1:1.5) and ammonium acrylate dispersant (accounting for 0.6wt% of the mixture) Mix well, use a ball mill for premixing and dispersion, and use a horizontal sand mill to re-disperse the initially dispersed slurry to obtain a sand-ground mixed slurry. Then use a spray dryer to carry out spray drying. The inlet temperature is 250±5°C and the outlet temperature is 120±5°C. The spray-dried powder is passed through an 80-mesh sieve to obtain the required low-temperature co-fired ceramic material.

The screened low-temperature co-fired ceramic material powder was pressed into discs using a tablet press, and the pressed discs were heat-insulated and sintered at 900°C for 4 hours for microwave dielectric property testing.

Example 3

其中，所述低熔點玻璃粉包括如下重量份的組分：

The low-temperature co-fired ceramic material in this embodiment includes the following mass content components based on the total amount of raw materials for its preparation:

Wherein, the low melting point glass powder includes the following components by weight:

The preparation method of low-temperature co-fired ceramic materials described in this embodiment includes the following steps: (1) According to the selected stoichiometric ratio, weigh the corresponding weights of BaCO ₃ and TiO ₂ and add water (material: water = 1:1.3) Mix evenly with ammonium acrylate dispersant (accounting for 0.9wt% of the powder), use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion , to obtain a uniformly dispersed slurry; (2) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 1%, and use a calciner to calcine the dried powder at 1080°C with a holding time of 4 hours , obtain BaTi ₄ O ₉ for later use; (3) According to the selected stoichiometric ratio, weigh the corresponding weight of Mg(OH) ₂ and SiO ₂ , add water (material: water = 1:1.2) and ammonium acrylate dispersant ( 1wt% of the amount of the powder) and mix evenly, use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion to obtain a uniformly dispersed slurry. ; (4) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 0.5%, and use a calciner to calcine the dried powder at 1210°C for a holding time of 3 hours to obtain Mg ₂ SiO ₄ . (5) According to the selected mass content ratio, mix the ZnO, SiO ₂ , B ₂ O ₃ and Al ₂ O ₃ evenly, and perform melting treatment at 1300°C. After the molten glass is cooled, use Roller machine is used for pulverization, and after pulverization, it is ground with a dry ball mill and a jet pulverizer. The particle size after grinding is required to be less than 2 μm to obtain the required low melting point glass powder for later use; (6) Take the selected content of the glass powder and the steps ( 2), (4) BaTi ₄ O ₉ and Mg ₂ SiO ₄ , add water (material: water = 1:1.4) and ammonium acrylate dispersant (accounting for 0.7wt% of the mixture), mix well, use a ball mill Premix and disperse, and the initially dispersed slurry is redispersed using a horizontal sand mill to obtain a sanded mixed slurry. Then use a spray dryer to carry out spray drying. The inlet temperature is 250±5°C and the outlet temperature is 120±5°C. The spray-dried powder is passed through an 80-mesh sieve to obtain the required low-temperature co-fired ceramic material.

The screened low-temperature co-fired ceramic material powder was pressed into discs using a tablet press, and the pressed discs were heat-insulated and sintered at 900°C for 4 hours for microwave dielectric property testing.

Example 4

其中，所述低熔點玻璃粉包括如下重量份的組分：

The low-temperature co-fired ceramic material in this embodiment includes the following mass content components based on the total amount of raw materials for its preparation:

Wherein, the low melting point glass powder includes the following components by weight:

The preparation method of low-temperature co-fired ceramic materials described in this embodiment includes the following steps: (1) According to the selected stoichiometric ratio, weigh the corresponding weights of BaCO ₃ and TiO ₂ and add water (material: water = 1:1.3) Mix evenly with ammonium acrylate dispersant (accounting for 0.8wt% of the powder), use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion. , to obtain a uniformly dispersed slurry; (2) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 1%, and use a calciner to calcine the dried powder at 1070°C with a holding time of 4 hours , obtain BaTi ₄ O ₉ for later use; (3) According to the selected stoichiometric ratio, weigh the corresponding weight of Mg(OH) ₂ and SiO ₂ , add water (material: water = 1:1.2) and ammonium acrylate dispersant ( 1wt% of the amount of the powder) and mix evenly, use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion to obtain a uniformly dispersed slurry. ; (4) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 0.5%, and use a calcining furnace to calcine the dried powder at 1200°C for 3 hours to obtain Mg ₂ SiO ₄ . (5) According to the selected mass content ratio, mix the ZnO, SiO ₂ , B ₂ O ₃ and Al ₂ O ₃ evenly, and perform melting treatment at 1300°C. After the molten glass is cooled, use Roller machine is used for pulverization, and after pulverization, dry ball mill and jet pulverizer are used for grinding. The particle size after grinding is required to be less than 2 μm to obtain the required low melting point glass powder for later use; (6) Take the selected content of the glass powder and the steps ( 2) and (4) BaTi ₄ O ₉ and Mg ₂ SiO ₄ , add water (material: water = 1:1.3) and ammonium acrylate dispersant (accounting for 0.7wt% of the mixture), mix well, and use a ball mill. Premix and disperse, and the initially dispersed slurry is redispersed using a horizontal sand mill to obtain a sanded mixed slurry. Then use a spray dryer to carry out spray drying. The inlet temperature is 250±5°C and the outlet temperature is 120±5°C. The spray-dried powder is passed through an 80-mesh sieve to obtain the required low-temperature co-fired ceramic material.

The screened low-temperature co-fired ceramic material powder was pressed into discs using a tablet press, and the pressed discs were heat-insulated and sintered at 900°C for 4 hours for microwave dielectric property testing.

Example 5

其中，所述低熔點玻璃粉包括如下重量份的組分：

The low-temperature co-fired ceramic material in this embodiment includes the following mass content components based on the total amount of raw materials for its preparation:

Wherein, the low melting point glass powder includes the following components by weight:

The preparation method of low-temperature co-fired ceramic materials described in this embodiment includes the following steps: (1) According to the selected stoichiometric ratio, weigh the corresponding weights of BaCO ₃ and TiO ₂ and add water (material: water = 1:1.3) Mix evenly with ammonium acrylate dispersant (accounting for 0.8wt% of the powder), use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion. , to obtain a uniformly dispersed slurry; (2) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 1%, and use a calciner to calcine the dried powder at 1080°C with a holding time of 4 hours , obtain BaTi ₄ O ₉ for later use; (3) According to the selected stoichiometric ratio, weigh the corresponding weight of Mg(OH) ₂ and SiO ₂ , add water (material: water = 1:1.2) and ammonium acrylate dispersant ( 1wt% of the amount of the powder) and mix evenly, use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion to obtain a uniformly dispersed slurry. ; (4) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 0.5%, and use a calcining furnace to calcine the dried powder at 1200°C for 3 hours to obtain Mg ₂ SiO ₄ . (5) According to the selected mass content ratio, mix the ZnO, SiO ₂ , B ₂ O ₃ and Al ₂ O ₃ evenly, and perform melting treatment at 1300°C. After the molten glass is cooled, use Roller machine is used for pulverization, and after pulverization, dry ball mill and jet pulverizer are used for grinding. The particle size after grinding is required to be less than 2 μm to obtain the required low melting point glass powder for later use; (6) Take the selected content of the glass powder and the steps ( 2) and (4) BaTi ₄ O ₉ and Mg ₂ SiO ₄ , add water (material: water = 1:1.3) and ammonium acrylate dispersant (accounting for 0.7wt% of the mixture), mix well, and use a ball mill. Premix and disperse, and the initially dispersed slurry is redispersed using a horizontal sand mill to obtain a sanded mixed slurry. Then use a spray dryer to carry out spray drying. The inlet temperature is 250±5°C and the outlet temperature is 120±5°C. The spray-dried powder is passed through an 80-mesh sieve to obtain the required low-temperature co-fired ceramic material.

The screened low-temperature co-fired ceramic material powder was pressed into discs using a tablet press, and the pressed discs were heat-insulated and sintered at 900°C for 4 hours for microwave dielectric property testing.

Example 6

其中，所述低熔點玻璃粉包括如下重量份的組分：

The low-temperature co-fired ceramic material in this embodiment includes the following mass content components based on the total amount of raw materials for its preparation:

Wherein, the low melting point glass powder includes the following components by weight:

The preparation method of low-temperature co-fired ceramic materials described in this embodiment includes the following steps: (1) According to the selected stoichiometric ratio, weigh the corresponding weights of BaCO ₃ and TiO ₂ and add water (material: water = 1:1.2) Mix evenly with ammonium acrylate dispersant (accounting for 0.7wt% of the powder), use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion , to obtain a uniformly dispersed slurry; (2) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 1%, and use a calciner to calcine the dried powder at 1090°C with a holding time of 4 hours , obtain BaTi ₄ O ₉ for later use; (3) According to the selected stoichiometric ratio, weigh the corresponding weight of Mg(OH) ₂ and SiO ₂ , add water (material: water = 1:1.2) and ammonium acrylate dispersant ( 1wt% of the amount of the powder) and mix evenly, use a ball mill to premix for 3 hours, and after ball milling, use a horizontal sand mill (the grinding medium uses 0.65mm zirconium balls) for further dispersion to obtain a uniformly dispersed slurry. ; (4) Use a spray dryer to dry the dispersed slurry until the moisture content is less than 0.5%, and use a calcining furnace to calcine the dried powder at 1200°C for 3 hours to obtain Mg ₂ SiO ₄ . (5) According to the selected mass content ratio, mix the ZnO, SiO ₂ , B ₂ O ₃ and Al ₂ O ₃ evenly, and perform melting treatment at 1300°C. After the molten glass is cooled, use Roller machine is used for pulverization, and after pulverization, dry ball mill and jet pulverizer are used for grinding. The particle size after grinding is required to be less than 2 μm to obtain the required low melting point glass powder for later use; (6) Take the selected content of the glass powder and the steps ( 2), (4) BaTi ₄ O ₉ and Mg ₂ SiO ₄ , add water (material: water = 1:1.3) and ammonium acrylate dispersant (accounting for 0.9wt% of the mixture), mix well, use a ball mill Premix and disperse, and the initially dispersed slurry is redispersed using a horizontal sand mill to obtain a sanded mixed slurry. Then use a spray dryer to carry out spray drying. The inlet temperature is 250±5°C and the outlet temperature is 120±5°C. The spray-dried powder is passed through an 80-mesh sieve to obtain the required low-temperature co-fired ceramic material.

The screened low-temperature co-fired ceramic material powder was pressed into discs using a tablet press, and the pressed discs were heat-insulated and sintered at 900°C for 4 hours for microwave dielectric property testing.

Comparative example 1

The preparation raw materials and preparation method of the ceramic material described in this comparative example are the same as those in Example 1. The only difference is that magnesium silicate is not added.

The low-temperature co-fired ceramic material described in Comparative Example 1 includes the following mass content components based on the total amount of raw materials for its preparation:

The low-temperature co-fired ceramic material described in Comparative Example 1 is prepared in the same manner as in Example 1 except that it does not contain magnesium silicate.

The low-temperature co-fired ceramic material powder obtained in the above-mentioned Examples 1-6 and Comparative Example 1 was sieved and pressed into discs using a tablet press, and the pressed discs were thermally insulated and sintered at 900°C for 4 hours for microwave dielectric testing. Performance test, the test results are shown in Table 1.

It can be seen from the above data that the sample density of the BaTi ₄ O ₉ + glass + Mg ₂ SiO ₄ material system is around 3.5-3.6, the shrinkage is 12-13%, the dielectric constant is between 21-25, and the loss is less than 2 ×10 ^-3 , the temperature coefficient of resonant frequency is less than 1. The temperature coefficient of the resonant frequency of the sample of Comparative Example 1 prepared under the same conditions is 66.7, indicating that under the sintering conditions of 900°C for 4 hours, the sample of Comparative Example 1 without the addition of magnesium silicate will cause the temperature coefficient of the resonant frequency to be too high and cannot be used.

Obviously, the above-mentioned embodiments are only examples for clear explanation and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. An exhaustive list of all implementations is neither necessary nor possible. The obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims (8)

A low-temperature co-fired ceramic material includes a matrix component, which includes the following components by mass:

Wherein, the low melting point glass powder includes the following components in parts by weight:

The low-temperature co-fired ceramic material according to claim 1, wherein the low melting point glass powder further includes: BaO 0-5 parts by weight; Li ₂ O 0-5 parts by weight. The low-temperature co-fired ceramic material as described in any one of claims 1-2, wherein the low-temperature co-fired ceramic material further includes additives, and the content of the additives is 0.5-5 wt% of the total mass of the matrix component. The low-temperature co-fired ceramic material of claim 3, wherein the additive includes one or more oxides or carbonates selected from B, Zn, Cu or Li. A low-temperature co-fired ceramic slurry, which includes the low-temperature co-fired ceramic material as described in any one of claims 1-4 and organic additives. A green ceramic belt, which includes a sintered low-temperature co-fired ceramic material as described in any one of claims 1 to 4, or a sintered low-temperature co-fired ceramic slurry as described in claim 5. A method using the low-temperature co-fired ceramic material as described in any one of claims 1 to 4, the low-temperature co-fired ceramic slurry as described in claim 5, or the green ceramic tape as described in claim 6 for preparing microwave dielectric ceramics The purpose of the device. A microwave dielectric ceramic device, which includes a sintered low-temperature co-fired ceramic material as described in any one of claims 1 to 4, or a sintered low-temperature co-fired ceramic slurry as described in claim 5, or as claimed in claim 5 The green porcelain belt described in 6.