A microwave dielectric ceramic material with a medium dielectric constant and low sintering temperature and a preparation method thereof

Abstract

The present invention relates to a microwave dielectric ceramic material with a medium dielectric constant and a preparation method thereof. Specifically, by using a low-melting-point sintering aid in the preparation process of the ceramic material, the present invention realizes the low-temperature sintering of the ceramic material and obtains a microwave dielectric ceramic material with excellent microwave dielectric properties.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic information functional ceramic materials and devices, and particularly relates to a microwave dielectric ceramic material with a medium dielectric constant and low sintering temperature and a preparation method thereof. Background Art

[0002] With the development of mobile communication technology, high-frequency, integrated, highly reliable, and low-latency requirements are put forward for microwave communication systems. Especially with the development of 5G and the layout of 6G, and the continuous upgrade of mobile communication technology, strong demands are put forward for the low loss, low latency, and miniaturization of mobile communication devices, thus posing higher challenges to the indispensable microwave dielectric ceramic materials used therein. As an indispensable microwave dielectric ceramic in mobile communication devices, it plays an irreplaceable role in the future communication era. Therefore, developing new microwave dielectric ceramic materials with excellent properties such as low sintering temperature, continuously adjustable dielectric constant, low loss, and near-zero temperature-frequency coefficient has important engineering significance and commercial value.

[0003] The research on microwave ceramic materials with a complex perovskite structure began in the 1990s. Among them, Ba(Mg 1 / 3 Ta 2 / 3 )O 3 (BMT) and Ba(Zn 1 / 3 Ta 2 / 3 )O 3 (BZT) ceramic materials have excellent microwave dielectric properties and can be used to prepare devices such as microwave filters and resonators, and have been commercially applied. However, due to the high price of Ta 2 O 5 , it raises its raw material cost and limits its large-scale application, prompting researchers to explore more inexpensive materials with excellent microwave properties. Nb 2 O 5 is an oxide with a wide source and low price. Using it to replace Ta 2 O 5 can also prepare microwave dielectric ceramic materials with good performance under appropriate conditions, namely Ba(Zn 1 / 3 Nb 2 / 3 )O 3 (BZN) ceramics. As early as in the 1980s, Shoichiro et al. reported the excellent microwave properties of BZN ceramics: Qf≈87000GHz (9.5GHz), ε r =41, τ f =31ppm / ℃. In the past nearly 40 years, researchers have conducted a large number of studies on BZN microwave dielectric ceramics, including research on the optimization of ceramic sintering processes, formulation design, annealing processes, etc. In 2018, Lingxia et al. used Mo6+ Replace a small amount of Nb 5+ Study on the modification of the microwave properties of BZN ceramics. After sintering at 1435 °C and annealing at 1300 °C, Ba 3 Zn(Nb 1.992 Mo 0.008 )O 9.004 The sample has the best microwave properties: Qf = 102931 GHz (~6 GHz), ε r = 38.9, τ f = 19.2 ppm / °C. However, in the previous research work, the sintering temperature of the material was greater than 1300 °C, which could not be co-fired with metal electrodes such as Cu and Ag, and could not meet the requirements of the current low-temperature co-fired ceramic (LTCC) passive integration technology. SUMMARY OF THE INVENTION

[0004] The object of the present invention is to provide a low-temperature sintering microwave dielectric ceramic material and its preparation and application.

[0005] In the first aspect of the present invention, a BZN-based microwave dielectric ceramic material is provided, and the ceramic material is obtained by sintering BZN powder and a sintering aid;

[0006] The composition of the BZN powder is Ba(Zn 1 / 3 Nb 2 / 3 )O 3 , and the volume percentage of the BZN powder in the ceramic material is 50-99.9%;

[0007] The composition of the sintering aid is aA x O y –bWO 3 , and the volume percentage of the sintering aid in the ceramic material is 0.1-50%;

[0008] Among them, A is an element selected from the following group: Li, Na, K, Ag, Mg, Ca, Sr, Ba, Zn, Cu, Fe, Co, Ni, Pb, Sn, rare earth elements, B, Al, Ga, In, Bi, Zr, Hf, Ti;

[0009] 1≤x≤2, 1≤y≤2;

[0010] 0<a≤2, 0<b≤3.

[0011] In another preferred example, the volume percentage of the BZN powder in the ceramic material is 60-99%, preferably 70-98%, more preferably 80-97%, and most preferably 85-96%.

[0012] In another preferred embodiment, the sintering aid accounts for 1-40% by volume of the ceramic material, preferably 2-30%, more preferably 3-20%, and most preferably 4-15%.

[0013] In another preferred embodiment, x is 1 or 2; and / or

[0014] y is 1, 1.5 or 2.

[0015] In another preferred embodiment, a is 0.5, 1, 1.5 or 2; and / or

[0016] b is 1, 2 or 3.

[0017] In another preferred embodiment, the ceramic material has one or more of the following characteristics:

[0018] 1) The quality factor Qf of the ceramic material is 3000-100000 GHz, preferably 5000-95000 GHz, more preferably 8000-80000 GHz, and most preferably 10000-70000 GHz;

[0019] 2) The dielectric constant ε of the ceramic material r is 18-50, preferably 20-45, more preferably 25-42, and most preferably 30-41;

[0020] 3) The temperature-frequency coefficient τ of the ceramic material f is -50 to +50 ppm / °C, preferably -20 to +20 ppm / °C, more preferably -10 to +10 ppm / °C, and most preferably -2 to +6 ppm / °C.

[0021] In a second aspect of the present invention, there is provided a method for preparing the ceramic material according to the first aspect of the present invention, the method comprising the following steps:

[0022] 1) Providing BZN powder, a sintering aid, and a dispersant;

[0023] 2) Mixing the BZN powder and the sintering aid to obtain a first mixture, and ball-milling the first mixture and the dispersant to obtain a ball-milled first mixture;

[0024] 3) Drying the ball-milled first mixture to obtain a dried first mixture;

[0025] 4) Compressing and molding the dried first mixture to obtain a ceramic green body;

[0026] 5) Sintering the ceramic green body in air to obtain the ceramic material according to the first aspect of the present invention.

[0027] In another preferred embodiment, the BZN powder is prepared as follows:

[0028] a-1) Provide Component One, Component Two, Component Three, and a dispersant;

[0029] Component One is an oxide, hydroxide, chloride, carbonate, nitrate, or sulfate of Ba;

[0030] Component Two is an oxide, hydroxide, chloride, carbonate, nitrate, or sulfate of Zn;

[0031] Component Three is an oxide, hydroxide, chloride, carbonate, nitrate, or sulfate of Nb;

[0032] a-2) Weigh Component One, Component Two, and Component Three according to the ratio of Ba(Zn 1 / 3 Nb 2 / 3 )O 3 to obtain a raw material composition; mix the raw material composition and the dispersant, and ball mill to obtain a ball-milled raw material composition;

[0033] a-3) Dry the ball-milled raw material composition to obtain a dried raw material composition;

[0034] a-4) Sinter the dried raw material composition in an oxygen atmosphere to obtain the BZN powder.

[0035] In another preferred example, Component One is selected from the group consisting of barium carbonate, barium nitrate, barium sulfate, or a combination thereof.

[0036] In another preferred example, Component Two is selected from the group consisting of zinc oxide, zinc nitrate, zinc carbonate, or a combination thereof.

[0037] In another preferred example, Component Three is selected from the group consisting of niobium oxide, niobium carbonate, niobium chloride, or a combination thereof.

[0038] In another preferred example, the dispersant is selected from the group consisting of absolute ethanol, deionized water, or a combination thereof.

[0039] In another preferred example, in step a-2), the mass ratio of the raw material composition, the dispersant, and the balls is 1:2:2.

[0040] In another preferred example, in step a-2), the balls are alumina balls.

[0041] In another preferred example, in step a-2), the ball milling time is 6 - 10 h, preferably 7 - 9 h, more preferably 8 h.

[0042] In another preferred example, in step a-2), the ball milling speed is 300 - 500 rpm.

[0043] In another preferred example, in step a-3), the drying temperature is 80 °C.

[0044] In another preferred example, in step a-4), the sintering temperature is 1000 - 1500 °C, preferably 1000 - 1200 °C, more preferably 1000 °C.

[0045] In another preferred example, in step a-4), the sintering treatment time is 2 - 10 h, preferably 3 - 5 h, more preferably 4 h.

[0046] In another preferred example, after step a-4), the obtained BZN powder is further subjected to grinding and sieving treatments.

[0047] In another preferred example, the particle size of the BZN powder is 0.1 - 1000 um, preferably 1 - 500 um, more preferably 10 - 250 um, and most preferably 20 - 120 um.

[0048] In another preferred example, the sintering aid is prepared as follows:

[0049] b-1) Provide component four, tungsten oxide, and a dispersant;

[0050] Component four is an oxide, hydroxide, carbonate, nitrate, or sulfate of A;

[0051] b-2) Weigh component four and tungsten oxide in the ratio of aA x O y –bWO 3 to obtain a sintering aid raw material composition; mix the sintering aid raw material composition and the dispersant, and ball mill to obtain a ball-milled sintering aid raw material composition;

[0052] b-3) Dry the ball-milled sintering aid raw material composition to obtain a dried sintering aid raw material composition;

[0053] b-4) Sinter the dried sintering aid raw material composition in an air atmosphere to obtain the sintering aid.

[0054] In another preferred example, the dispersant is selected from the group consisting of anhydrous ethanol, deionized water, or a combination thereof.

[0055] In another preferred example, in step b-2), the mixing mass ratio of the sintering aid raw material composition, the dispersant, and the balls is 1:2:2.

[0056] In another preferred example, in step b-2), the balls are zirconia balls.

[0057] In another preferred example, in step b-2), the ball milling time is 6 - 10 h, preferably 7 - 9 h, more preferably 8 h.

[0058] In another preferred example, in step b-2), the ball milling rotation speed is 300-500 rpm.

[0059] In another preferred example, in step b-3), the drying temperature is 80 °C.

[0060] In another preferred example, in step b-4), the sintering temperature is 500-1000 °C, preferably 600-900 °C, more preferably 650-850 °C.

[0061] In another preferred example, in step b-4), the sintering treatment time is 3-6 h, preferably 3-5 h, more preferably 4 h.

[0062] In another preferred example, after step b-4), the obtained sintering aid is also subjected to grinding and sieving treatments.

[0063] In another preferred example, the particle size of the sintering aid is 0.01-100 um, preferably 0.1-80 um, more preferably 1-50 um, and most preferably 2-30 um.

[0064] In another preferred example, the preparation method has one or more of the following characteristics:

[0065] i-1) In step 2), the mixing mass ratio of the first mixture, the dispersant and the balls is 1:2:2-7;

[0066] i-2) In step 2), the balls are zirconia balls;

[0067] i-3) In step 2), the ball milling time is 6-10 h, preferably 7-9 h, more preferably 8 h;

[0068] i-4) In step 2), the ball milling rotation speed is 300-500 rpm;

[0069] i-5) In step 3), the drying temperature is 80 °C;

[0070] i-6) In step 4), the pressing and forming is a two-stage pressing and forming:

[0071] Stage 1: Dry pressing and forming at 10-50 MPa (preferably 15-25 MPa);

[0072] Stage 2: Cold isostatic pressing and forming at 150-250 MPa (preferably 180-220 MPa);

[0073] i-7) In step 5), the temperature of the sintering treatment is 650-950 °C, preferably 750-940 °C, more preferably 850-930 °C, and most preferably 900-930 °C;

[0074] i - 8) In step 5), the sintering treatment time is 0.5 - 3 h, preferably 0.8 - 2.5 h, more preferably 1 - 2 h.

[0075] In the third aspect of the present invention, there is provided a use of the ceramic material described in the first aspect of the present invention for preparing electronic components selected from the group consisting of LTCC filters and resonators.

[0076] It should be understood that within the scope of the present invention, the above - mentioned technical features of the present invention and the technical features specifically described below (such as in the examples) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be elaborated one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 This is the XRD pattern (upper figure) of the main material BZN powder obtained after calcination at 1000 °C in the present invention.

[0078] Figure 2 This is the SEM image of the main material BZN powder obtained after calcination at 1000 °C in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0079] Through long - term and in - depth research, the inventor of the present invention can achieve low - temperature sintering at 650 - 950 °C by introducing a low - melting - point sintering aid in the preparation process of microwave dielectric ceramic materials, thereby obtaining a BZN - based microwave dielectric ceramic material with excellent microwave dielectric properties. On this basis, the inventor completed the present invention.

[0080] By introducing a low - melting - point sintering aid and optimizing the formulation adjustment and synthesis process of BZN - based ceramics, the present invention reduces the sintering temperature to below 950 °C, does not chemically react with Cu and Ag electrodes, and has excellent microwave properties such as continuously adjustable medium dielectric constant and low dielectric loss.

[0081] Compared with the prior art, the present invention has the following main advantages:

[0082] (1) The ceramic material described in the present invention has excellent microwave dielectric properties;

[0083] (2) The manufacturing method described in the present invention can obtain a BZN - based microwave dielectric ceramic material with excellent microwave dielectric properties by low - temperature sintering at 650 - 950 °C by using a tungsten - containing oxide sintering aid;

[0084] (3) The ceramic material described in the present invention can achieve the temperature - frequency coefficient τ of BZN - based ceramics f within the near - zero range;

[0085] (4) The ceramic material of the present invention can achieve co-firing of BZN-based components and ceramic substrates at low temperatures, making integration easier.

[0086] The following describes the present invention in further detail with reference to specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer. Unless otherwise specified, percentages and parts are calculated by weight.

[0087] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to those described herein can be applied to the methods of the present invention. The preferred implementation methods and materials described herein are for illustrative purposes only.

[0088] The relevant microwave dielectric property testing equipment used in the present invention includes a network analyzer (E5227B, Keysight, American) and a temperature control box (CORP / SH-222, ESPEC, Japan).

[0089] Specifically, the microwave dielectric properties of the present invention were measured under the following conditions: room temperature, standard atmospheric pressure, and humidity of 35%-40%.

[0090] Synthesis of the main BZN powder

[0091] First, the main BZN raw materials are BaCO 3 , ZnO, Nb 2 O 5 , and they are proportioned according to the chemical formula Ba(Zn 1 / 3 Nb 2 / 3 )O 3 . The synthesis of the main BZN raw materials includes the following two steps:

[0092] Step 1: Ball-mill the ingredients. Among them, for wet ball-milling, the mass ratio of the ingredients: dispersant: balls is 1:2:2. The dispersant is anhydrous ethanol, and the balls are alumina balls with a diameter of 3-10 mm. The ball-milling time is 8 hours, and the rotation speed is 300-500 revolutions per minute.

[0093] Step 2: After the ball-milling is completed, take out the slurry and place it in a glassware. Dry it in an 80°C oven. The obtained powder is subjected to calcination treatment in an oxygen atmosphere at 1000°C for 4 hours, and then cooled to room temperature with the furnace. The obtained powder with a pure BZN phase is then ground and passed through a 120-mesh sieve to obtain the required main BZN powder.

[0094] Figure 1XRD pattern (upper figure) of the main material BZN powder obtained after calcination at 1000 °C in the present invention.

[0095] From Figure 1 it can be seen that the obtained powder is a pure BZN phase without impurity phases.

[0096] Figure 2 SEM image of the main material BZN powder obtained after calcination at 1000 °C in the present invention.

[0097] From Figure 2 it can be seen that the particle size distribution of the powder after calcination is relatively uniform, and the average particle size is about 1 μm.

[0098] Preparation of the sintering aid

[0099] Using aA x O y –bWO 3 as the sintering aid, which is prepared as follows:

[0100] aA x O y –bWO 3 Using the oxide, hydroxide, carbonate, nitrate or sulfate of A, WO 3 as raw materials, and proportioning according to the ratio of a:b. The synthesis of the sintering aid includes the following two steps:

[0101] Step 1: Ball-mill the proportioned materials. Among them, according to the mass ratio, the material: dispersant: ball = 1:2:2 for wet ball-milling. The dispersant is anhydrous ethanol, and the ball is a zirconia ball with a diameter of 3 - 10 mm. The ball-milling time is 8 hours, and the rotation speed is 300 - 500 revolutions per minute.

[0102] Step 2: After the ball-milling is completed, take out the slurry and place it in a glassware, dry it in an 80 °C oven. The obtained powder is subjected to calcination treatment in an air atmosphere at 600 - 1000 °C for 4 hours of heat preservation time, and then cooled to room temperature with the furnace. Then, the obtained solid is ground and passed through a 120-mesh sieve to obtain the required sintering aid glass powder.

[0103] Example 1

[0104] Using aNa 2 O–bWO 3 as the sintering aid, with a = b = 1 (i.e., the molar ratio of Na 2 O and WO 3 is 1:1), accurately weigh the masses of Na 2 CO 3 and WO 3 and prepare aNa 2 O–bWO by ball-milling, mixing, drying, calcining, grinding, and sieving3 Sintering agent powder Z1, weigh the above 90vol.%BZN powder and 10vol.%aNa 2 O–bWO 3 Powder Z1 is mixed by ball milling, and the specific steps are as follows:

[0105] Step 1: Mixing ingredients. BZN powder and powder Z1 are accurately weighed according to the formula, wherein the volume percentage of BZN powder is 90 vol.%, and the volume percentage of powder Z1 is 10 vol.%.

[0106] Step 2: ball milling. The raw materials weighed in step 1 are placed in a ball mill for ball milling, wherein the mass ratio of raw material powder: dispersant: grinding ball is 1:2:2, the dispersant is anhydrous ethanol, and the grinding ball is zirconia ball, and the ball milling is carried out on a planetary ball mill at 300-500 rpm for 8 hours.

[0107] Step 3: Drying: The slurry obtained after ball milling in step 2 is dried at 80° C., ground, and passed through a 200-mesh sieve to obtain the desired BZN-based ceramic powder.

[0108] Step 4: Molding: The powder in step 3 is dry pressed at a pressure of 20 MPa to obtain a ceramic body, and then the ceramic body is cold isostatically pressed at 200 MPa to obtain a ceramic green body to be sintered.

[0109] Step 5: Sintering. The ceramic blank in step 4 is sintered in air at a temperature of 900°C for 1 hour to obtain BZN-(aNa 2 O–bWO 3 )Low temperature co-fired microwave dielectric ceramic materials1.

[0110] The microwave dielectric properties of microwave dielectric ceramic material 1 are: Qf = 67075GHz, ε r =35.5, τ f =+5.8ppm / ℃.

[0111] Example 2

[0112] Using a(Na 0.9 Ag 0.1 ) 2 O–bWO 3 As a sintering aid, according to a = b = 1 (i.e. the molar ratio of the two components is 1:1), accurately weigh Na 2 CO 3 , Ag 2 O and WO 3 The mass was ball-milled, dried, burned, ground, and sieved to obtain a(Na 0.9 Ag 0.1 )2 O–bWO 3 Sintering agent powder Z2, weigh the above 95vol.% BZN powder and 5vol.% a(Na 0.9 Ag 0.1 ) 2 O–bWO 3 Powder Z2 is mixed by ball milling, and the specific steps are as follows:

[0113] Step 1: Mixing ingredients. BZN powder and powder Z2 are accurately weighed according to the formula, wherein the volume percentage of BZN powder is 95 vol.%, and the volume percentage of powder Z2 is 5 vol.%.

[0114] Step 2: ball milling. The raw materials weighed in step 1 are placed in a ball mill for ball milling, wherein the mass ratio of raw material powder: dispersant: grinding ball is 1:2:2, the dispersant is anhydrous ethanol, and the grinding ball is zirconia ball, and the ball milling is carried out on a planetary ball mill at 300-500 rpm for 8 hours.

[0115] Step 3: Drying: The slurry obtained after ball milling in step 2 is dried at 80° C., ground, and passed through a 200-mesh sieve to obtain the desired BZN-based ceramic powder.

[0116] Step 4: Molding: The powder in step 3 is dry pressed at a pressure of 20 MPa to obtain a ceramic body, and then the ceramic body is cold isostatically pressed at 200 MPa to obtain a ceramic green body to be sintered.

[0117] Step 5: Sintering. The ceramic blank in step 4 is sintered in air at a temperature of 930°C for 2 hours to obtain BZN-a(Na 0.9 Ag 0.1 ) 2 O–bWO 3 Low temperature co-fired microwave dielectric ceramic materials2.

[0118] The dielectric properties of microwave dielectric ceramic material 2 are: Qf = 55960 GHz, ε r =38.2, τ f =+1.9ppm / ℃.

[0119] Example 3

[0120] Using a(Na 0.8 Ag 0.2 ) 2 O–bWO 3 As a sintering aid, according to a = b = 1 (i.e. the molar ratio of the two components is 1:1), accurately weigh Na 2 CO 3 、Ag 2 O and WO3 The mass was ball-milled, dried, burned, ground, and sieved to obtain a(Na 0.8 Ag 0.2 ) 2 O–bWO 3 Sintering agent powder Z3, weigh the above 90vol.% BZN powder and 10vol.% a(Na 0.8 Ag 0.2 ) 2 O–bWO 3 Powder Z3 is mixed by ball milling, and the specific steps are as follows:

[0121] Step 1: Mixing: BZN powder and Z3 powder are accurately weighed according to the formula, wherein the volume percentage of BZN powder is 90 vol.%, and the volume percentage of Z3 powder is 10 vol.%.

[0122] Step 2: ball milling. The raw materials weighed in step 1 are placed in a ball mill for ball milling, wherein the mass ratio of raw material powder: dispersant: grinding ball is 1:2:2, the dispersant is anhydrous ethanol, and the grinding ball is zirconia ball, and the ball milling is carried out on a planetary ball mill at 300-500 rpm for 8 hours.

[0123] Step 3: Drying: The slurry obtained after ball milling in step 2 is dried at 80° C., ground, and passed through a 200-mesh sieve to obtain the desired BZN-based ceramic powder.

[0124] Step 4: Molding: The powder in step 3 is dry pressed at a pressure of 20 MPa to obtain a ceramic body, and then the ceramic body is cold isostatically pressed at 200 MPa to obtain a ceramic green body to be sintered.

[0125] Step 5: Sintering. The ceramic blank in step 4 is sintered in air at a temperature of 900°C for 1 hour to obtain BZN-(a(Na 0.8 Ag 0.2 ) 2 O–bWO 3 ) Low temperature co-fired microwave dielectric ceramic materials 3.

[0126] The microwave dielectric properties of microwave dielectric ceramic material 3 are: Qf = 31095GHz, ε r =35.5, τ f =+2.8ppm / ℃.

[0127] Example 4

[0128] Using aPbO–bWO 3 As a sintering aid, accurately weigh PbO and WO according to a=b=1 (i.e. the molar ratio of the two components is 1:1). 3The mass was ball-milled, dried, calcined, ground, and sieved to obtain aPbO–bWO 3 Sintering aid powder Z4, weigh the above 80vol.% BZN powder and 20vol.% aPbO–bWO 3 Powder Z4 is mixed by ball milling, the specific steps are as follows:

[0129] Step 1: Mixing: BZN powder and powder Z4 are accurately weighed according to the formula, wherein the volume percentage of BZN powder is 80 vol.%, and the volume percentage of powder Z4 is 20 vol.%.

[0130] Step 2: ball milling. The raw materials weighed in step 1 are placed in a ball mill for ball milling, wherein the mass ratio of raw material powder: dispersant: grinding ball is 1:2:2, the dispersant is anhydrous ethanol, and the grinding ball is zirconia ball, and the ball milling is carried out on a planetary ball mill at 300-500 rpm for 8 hours.

[0131] Step 3: Drying: The slurry obtained after ball milling in step 2 is dried at 80° C., ground, and passed through a 200-mesh sieve to obtain the desired BZN-based ceramic powder.

[0132] Step 4: Molding: The powder in step 3 is dry pressed at a pressure of 20 MPa to obtain a ceramic body, and then the ceramic body is cold isostatically pressed at 200 MPa to obtain a ceramic green body to be sintered.

[0133] Step 5: Sintering. The ceramic blank in step 4 is sintered in air at a temperature of 900°C for 1 hour to obtain BZN-(aPbO–bWO 3 )Low temperature co-fired microwave dielectric ceramic materials4.

[0134] The microwave dielectric properties of microwave dielectric ceramic material 4 are: Qf = 67760 GHz, ε r =37.1, τ f =+3.2ppm / ℃.

[0135] Example 5

[0136] Using aPbO–bWO 3 As a sintering aid, accurately weigh PbO and WO according to a=2, b=1 (i.e. the molar ratio of the two components is 2:1). 3 The mass was ball-milled, dried, calcined, ground, and sieved to obtain aPbO–bWO 3 Sintering aid powder Z5, weigh 95vol.%BZN powder and 5vol.%aPbO–bWO 3 Powder Z5 is mixed by ball milling, the specific steps are as follows:

[0137] Step 1: Batching. Accurately weigh the BZN powder and powder Z5 according to the formula, where the volume percentage of the BZN powder is 95 vol.%, and the volume percentage of the powder Z5 is 5 vol.%.

[0138] Step 2: Ball milling. Put the raw materials weighed in Step 1 into a ball milling tank for ball milling, where the mass ratio of the raw material powder: dispersant: grinding balls = 1:2:2, the dispersant is anhydrous ethanol, and the grinding balls are zirconia balls. Ball mill at 300 - 500 revolutions per minute on a planetary ball mill for 8 hours.

[0139] Step 3: Drying. Dry the slurry obtained after ball milling in Step 2 at 80 °C, grind it, and pass it through a 200 - mesh sieve to obtain the required BZN - based ceramic powder.

[0140] Step 4: Forming. Dry - press the powder in Step 3 under a pressure of 20 MPa to obtain a ceramic green body, and then perform cold isostatic pressing on the ceramic green body at 200 MPa to obtain a ceramic green body to be sintered.

[0141] Step 5: Sintering. Sinter the ceramic green body in Step 4 in air, with a sintering temperature of 920 °C and a sintering time of 2 hours, to obtain the excellent - performance BZN - (aPbO–bWO 3 ) low - temperature co - fired microwave dielectric ceramic material 5.

[0142] The microwave dielectric properties of the microwave dielectric ceramic material 5 are: Qf = 51600 GHz, ε r = 39.7, τ f = +1.8 ppm / °C.

[0143] Example 6

[0144] Use aLi 2 O–bWO 3 as a sintering aid. According to a = b = 1 (i.e., the molar ratio of the two components is 1:1), accurately weigh the masses of Li 2 CO 3 and WO 3 , and prepare the aLi 2 O–bWO 3 sintering aid powder Z6 through ball milling, mixing, drying, calcining, grinding, and sieving. Weigh 90 vol.% of the above - mentioned BZN powder and 10 vol.% of aLi 2 O–bWO 3 powder Z6 and mix them by ball milling. The specific steps are as follows:

[0145] Step 1: Batching. Weigh the BZN powder and powder Z6 precisely according to the formula, where the volume percentage of the BZN powder is 90 vol.%, and the volume percentage of the powder Z6 is 10 vol.%.

[0146] Step 2: Ball milling. Put the raw materials weighed in Step 1 into a ball milling jar for ball milling. Among them, the mass ratio of the raw material powder: dispersant: grinding balls = 1:2:2. The dispersant is anhydrous ethanol, and the grinding balls are zirconia balls. Ball mill at 300 - 500 revolutions per minute on a planetary ball mill for 8 hours.

[0147] Step 3: Drying. Dry the slurry obtained after ball milling in Step 2 at 80 °C, and obtain the required BZN-based ceramic powder after grinding and passing through a 200-mesh sieve.

[0148] Step 4: Forming. Dry-press the powder in Step 3 under a pressure of 20 MPa to obtain a ceramic green body, and then perform cold isostatic pressing on the ceramic green body at 200 MPa to obtain a ceramic green body to be sintered.

[0149] Step 5: Sintering. Sinter the ceramic green body in Step 4 in air. The sintering temperature is 915 °C, and the sintering time is 1 hour, then the excellent-performance BZN-(aLi 2 O–bWO 3 ) low-temperature co-fired microwave dielectric ceramic material 6 can be obtained.

[0150] The microwave dielectric properties of the microwave dielectric ceramic material 6 are: Qf = 41265 GHz, ε r = 36.5, τ f = +0.8 ppm / °C.

[0151] Example 7

[0152] Use a(Ag,Bi)O 2 –bWO 3 as a sintering aid. According to a = 0.5, b = 1 (i.e., the molar ratio of the two components is 0.5:1), accurately weigh the masses of Ag 2 O, Bi 2 O 3 and WO 3 , and carry out ball milling, mixing, drying, calcining, grinding, and sieving to obtain the a(Ag,Bi)O 2 –bWO 3 sintering aid powder Z7. Weigh 90 vol.% of the above BZN powder and 10 vol.% of the a(Ag,Bi)O 2 –bWO 3 powder Z7 and mix them by ball milling. The specific steps are as follows:

[0153] Step 1: Ingredients. BZN powder and powder Z7 are accurately weighed according to the formula, wherein the volume percentage of BZN powder is 90 vol.%, and the volume percentage of powder Z7 is 10 vol.%.

[0154] Step 2: ball milling. The raw materials weighed in step 1 are placed in a ball mill for ball milling, wherein the mass ratio of raw material powder: dispersant: grinding ball is 1:2:2, the dispersant is anhydrous ethanol, and the grinding ball is zirconia ball, and the ball milling is carried out on a planetary ball mill at 300-500 rpm for 8 hours.

[0155] Step 3: Drying: The slurry obtained after ball milling in step 2 is dried at 80° C., ground, and passed through a 200-mesh sieve to obtain the desired BZN-based ceramic powder.

[0156] Step 4: Molding: The powder in step 3 is dry pressed at a pressure of 20 MPa to obtain a ceramic body, and then the ceramic body is cold isostatically pressed at 200 MPa to obtain a ceramic green body to be sintered.

[0157] Step 5: Sintering. The ceramic blank in step 4 is sintered in air at a temperature of 925°C for 1 hour to obtain BZN-(a(Ag,Bi)O 2 –bWO 3 ) Low temperature co-fired microwave dielectric ceramic materials 7.

[0158] The microwave dielectric properties of microwave dielectric ceramic material 7 are: Qf = 10135 GHz, ε r =40.3,τ f =+1.7ppm / ℃.

[0159] Example 8

[0160] Using a(Li,Mg)O 1.5 –bWO 3 As a sintering aid, according to a = 2, b = 3 (i.e. the molar ratio of the two components is 2:3), accurately weigh Li 2 O, MgO and WO 3 The mass was ball-milled, dried, calcined, ground and sieved to obtain a(Li,Mg)O 1.5 –bWO 3 Sintering aid powder Z8, weigh the above 90vol.%BZN powder and 10vol.%a(Li,Mg)O 1.5 –bWO 3 Powder Z8 is mixed by ball milling, the specific steps are as follows:

[0161] Step 1: Ingredients. BZN powder and powder Z8 are accurately weighed according to the formula, wherein the volume percentage of BZN powder is 90 vol.%, and the volume percentage of powder Z8 is 10 vol.%.

[0162] Step 2: ball milling. The raw materials weighed in step 1 are placed in a ball mill for ball milling, wherein the mass ratio of raw material powder: dispersant: grinding ball is 1:2:2, the dispersant is anhydrous ethanol, and the grinding ball is zirconia ball, and the ball milling is carried out on a planetary ball mill at 300-500 rpm for 8 hours.

[0163] Step 3: Drying: The slurry obtained after ball milling in step 2 is dried at 80° C., ground, and passed through a 200-mesh sieve to obtain the desired BZN-based ceramic powder.

[0164] Step 4: Molding: The powder in step 3 is dry pressed at a pressure of 20 MPa to obtain a ceramic body, and then the ceramic body is cold isostatically pressed at 200 MPa to obtain a ceramic green body to be sintered.

[0165] Step 5: Sintering. The ceramic blank in step 4 is sintered in air at a temperature of 910°C for 1 hour to obtain BZN-(a(Li,Mg)O 1.5 –bWO 3 ) Low temperature co-fired microwave dielectric ceramic materials8.

[0166] The microwave dielectric properties of microwave dielectric ceramic material 8 are: Qf = 61735GHz, ε r =36.7, τ f =+1.3ppm / ℃.

[0167] Comparative Example 1

[0168] Same as Example 8, except that only a single oxide WO is used. 3 As a burning aid.

[0169] Using a single oxide WO 3 As a sintering aid, weigh the above 90 vol.% BZN powder and 10 vol.% WO 3 Powder D1 was mixed by ball milling, and the specific steps were as follows:

[0170] Step 1: Ingredients: BZN powder and powder D1 are accurately weighed according to the formula, wherein the volume percentage of BZN powder is 90 vol.%, and the volume percentage of powder D1 is 10 vol.%.

[0171] Step 2: Ball milling. Put the raw materials weighed in Step 1 into a ball milling tank for ball milling. Among them, the mass ratio of raw material powder: dispersant: grinding balls = 1:2:2. The dispersant is absolute ethanol, and the grinding balls are zirconia balls. Ball mill at 300 - 500 revolutions per minute on a planetary ball mill for 8 hours.

[0172] Step 3: Drying. Dry the slurry obtained after ball milling in Step 2 at 80 °C, grind it, and pass it through a 200-mesh sieve to obtain the required BZN-based ceramic powder.

[0173] Step 4: Molding. Dry-press the powder in Step 3 under a pressure of 20 MPa to obtain a ceramic green body, and then perform cold isostatic pressing on the ceramic green body at 200 MPa to obtain a ceramic green body to be sintered.

[0174] Step 5: Sintering. Sinter the ceramic green body in Step 4 in air. The sintering temperature is 900 - 1100 °C, and the sintering time is 1 hour to obtain the BZN-WO 3 ceramic material C1.

[0175] Due to the poor sintering aid effect of WO 3 , a relatively dense ceramic material cannot be obtained. In the temperature range of 900 - 1100 °C, the best density is only about 65%, and the microwave dielectric properties cannot be measured. At the same time, the high temperature of 1100 °C has exceeded the application range of LTCC.

[0176] Comparative Example 2

[0177] Same as Example 1, the difference is that: only the single oxide Na 2 2O is used as the sintering aid

[0178] Use Na 2 2O as the sintering aid D2. Weigh 90 vol.% of the above BZN powder and 10 vol.% of Na 2 2O powder D2 and mix them by ball milling. The specific steps are as follows:

[0179] Step 1: Batching. Accurately weigh the BZN powder and the powder D2 according to the formula. Among them, the volume percentage of the BZN powder is 90 vol.%, and the volume percentage of the powder D2 is 10 vol.%.

[0180] Step 2: Ball milling. Put the raw materials weighed in Step 1 into a ball milling tank for ball milling. Among them, the mass ratio of raw material powder: dispersant: grinding balls = 1:2:2. The dispersant is absolute ethanol, and the grinding balls are zirconia balls. Ball mill at 300 - 500 revolutions per minute on a planetary ball mill for 8 hours.

[0181] Step 3: Drying. Dry the slurry obtained after ball milling in Step 2 at 80 °C, grind it, and pass it through a 200-mesh sieve to obtain the required BZN-based ceramic powder.

[0182] Step 4: Molding. Dry-press the powder in Step 3 under a pressure of 20 MPa to obtain a ceramic green body, and then perform cold isostatic pressing on the ceramic green body at 200 MPa to obtain a ceramic green body to be sintered.

[0183] Step 5: Sintering. Sinter the ceramic green body in Step 4 in air. The sintering temperature is 1100 °C and the sintering time is 1 - 5 hours to obtain the BZN-Na 2 O ceramic material C2.

[0184] Due to the poor sintering aid effect of Na 2 O, a relatively dense ceramic material cannot be obtained. The best density at 1100 °C is only about 75%, and the microwave dielectric properties cannot be measured. At the same time, the high temperature of 1100 °C has exceeded the application range of LTCC.

[0185] Comparative Example 3

[0186] Using fluoride as a sintering aid, the BZN-L obtained in the optimal Example 1 of the patent with the application number 2021101088683 8 C 2 Low-temperature co-fired microwave dielectric ceramic material, the microwave dielectric properties are: Qf = 55045 GHz, ε r = 38.2, τ f = 27.8 ppm / °C, and its sintering temperature is 950 °C and the time is 10 hours.

[0187] Compared with it, the sintering time in the present invention is less than 10 hours, and moreover, the τ f value in the present invention is closer to 0. It can be seen that the material prepared by the present invention has the advantages of better performance and shorter sintering time, which is more conducive to further industrial production and application.

[0188] All the documents mentioned in the present invention are cited in this application as references, just as if each document is cited separately as a reference. In addition, it should be understood that after reading the above teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A BZN-based microwave dielectric ceramic material, characterized in that, the ceramic material is obtained by sintering BZN powder and a sintering aid; The composition of the BZN powder is Ba(Zn 1 / 3 Nb 2 / 3 )O 3 , and the volume percentage of the BZN powder in the ceramic material is 80-95%; The composition of the sintering aid is aA x O y – bWO 3 , and the volume percentage of the sintering aid in the ceramic material is 5-20%; wherein, A is selected from one or two of the following elements: Li, Na, K, Ag, Mg, Ca, Sr, Pb, Bi; 1 ≤ x ≤ 2, 1 ≤ y ≤ 2; 0 < a ≤ 2, 0 < b ≤ 3; the temperature of the sintering treatment is 650 - 950 °C; the time of the sintering treatment is 0.5 - 3 h.

2. The ceramic material according to claim 1, characterized in that, the volume percentage of the BZN powder in the ceramic material is 90 - 95%.

3. The ceramic material according to claim 1, characterized in that, the volume percentage of the sintering aid in the ceramic material is 5 - 10%.

4. The ceramic material according to claim 1, characterized in that, x is 1 or 2; and / or y is 1, 1.5 or 2.

5. The ceramic material according to claim 1, characterized in that, a is 0.5, 1, 1.5 or 2; and / or b is 1, 2 or 3.

6. A preparation method of the ceramic material according to claim 1, characterized in that, the preparation method comprises the following steps: 1) Provide BZN powder, a sintering aid, and a dispersant; 2) Mix the BZN powder and the sintering aid to obtain a first mixture, and ball-mill the first mixture and the dispersant to obtain a ball-milled first mixture; 3) Dry the ball-milled first mixture to obtain a dried first mixture; 4) Press the dried first mixture into a ceramic green body; 5) Sinter the ceramic green body in air to obtain the ceramic material according to claim 1.

7. The preparation method according to claim 6, characterized in that, the BZN powder is prepared as follows: a-1) Provide component one, component two, component three, and a dispersant; component one is an oxide, hydroxide, chloride, carbonate, nitrate, or sulfate of Ba; component two is an oxide, hydroxide, chloride, carbonate, nitrate, or sulfate of Zn; component three is an oxide, hydroxide, chloride, carbonate, nitrate, or sulfate of Nb; a-2) According to the ratio of Ba(Zn 1 / 3 Nb 2 / 3 )O 3 , ingredients of component one, component two and component three are proportioned to obtain a raw material composition; the raw material composition and a dispersant are mixed and ball-milled to obtain a ball-milled raw material composition; a-3) Dry the ball-milled raw material composition to obtain a dried raw material composition; a-4) Sinter the dried raw material composition in an oxygen atmosphere to obtain the BZN powder.

8. The preparation method according to claim 6, characterized in that, the sintering aid is prepared as follows: b-1) Provide component four, tungsten oxide, and a dispersant; component four is an oxide, hydroxide, carbonate, nitrate, or sulfate of A; b-2) According to aA x O y –bWO 3 Mix components four and tungsten oxide in the ratio to obtain a sintering aid raw material composition; mix the sintering aid raw material composition with a dispersant and ball mill to obtain a ball-milled sintering aid raw material composition; b-3) Dry the ball-milled sintering aid raw material composition to obtain a dried sintering aid raw material composition; b-4) Sinter the dried sintering aid raw material composition in an air atmosphere to obtain the sintering aid.

9. The preparation method according to claim 6, characterized in that, the preparation method has one or more of the following characteristics: i-1) In step 2), the mixing mass ratio of the first mixture, the dispersant, and the balls is 1:2:2 - 7; i-2) In step 2), the balls are zirconia balls. i-3) In step 2), the ball milling time is 6 - 10 h; i-4) In step 2), the ball milling speed is 300 - 500 rpm; i-5) In step 3), the drying temperature is 80 °C; i-6) In step 4), the pressing and forming is a two-stage pressing and forming: Stage 1: Dry pressing and forming at 10 - 50 MPa; Stage 2: Cold isostatic pressing and forming at 150 - 250 MPa; i-7) In step 5), the temperature of the sintering treatment is 650 - 950 °C; i-8) In step 5), the time of the sintering treatment is 0.5 - 3 h.

10. Use of the ceramic material according to claim 1, characterized in that it is used for preparing electronic components selected from the group consisting of LTCC filters and resonators.

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