Millimeter wave dielectric ceramic material with high thermal shock resistance and preparation method thereof

Abstract

The invention discloses a millimeter wave dielectric ceramic material with high thermal shock resistance and a preparation method thereof, and relates to the technical field of electronic information functional materials. The chemical formula of the millimeter wave dielectric ceramic material is Yb < 2-x > A < x > Si < 2-y > B < y > O < 7 >, A is one of La < 3 + >, Nd < 3 + >, Gd < 3 + > and Lu < 3 + > ions, B is one of Ti < 4 + > and Ge < 4 + > ions, x is more than 0 and less than or equal to 0.12, and y is more than 0 and less than or equal to 0.06. The contents of Yb, A, Si and B ions are controlled by regulating x and y values, so that the phase of the Yb2Si2O7 ceramic is stabilized, high thermal shock resistance is obtained, and the purpose of continuously working under an extreme temperature condition is finally achieved. The invention also discloses a preparation method of the millimeter wave dielectric ceramic material, which has the advantages of simple operation, high reliability and easy industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of electronic information functional materials, and in particular to a millimeter wave dielectric ceramic material with high thermal shock resistance and a preparation method thereof. Background Art

[0002] Millimeter wave dielectric ceramics refer to ceramics used as dielectric materials in millimeter wave (300MHz to 300GHz) frequency band circuits and perform one or more functions. As a new type of electronic material, millimeter wave dielectric ceramics are used as resonators, filters, dielectric substrates, dielectric antennas, dielectric waveguide circuits, etc. in modern communications and are widely used in many fields of millimeter wave technology.

[0003] Due to the implementation of the fifth generation of communication technology and the development of the sixth generation of communication technology, the pursuit of dielectric materials with high-speed signal transmission characteristics has become an urgent need. This urgency has greatly stimulated the development of low dielectric constant millimeter wave dielectric ceramic materials (εr<10), because the relative dielectric constant is generally considered to be inversely proportional to the signal transmission rate. In addition, driven by the rapid development of communication technology, the operating frequency has shifted to higher areas, indicating that it has great application potential in communication systems in the terahertz band in the future. Therefore, the exploration of millimeter wave dielectric ceramic materials can be applied not only to the millimeter wave band (low εr, high Q×f, and near-zero τf), but also to the terahertz band.

[0004] Low dielectric constant millimeter wave dielectric ceramic materials developed in recent years include silicates, molybdates and borates. Most ceramics with dielectric constants below 10 are silicate ceramics. This is because Si 4+ The ion polarizability is the smallest (0.87A 3 ), and the significant influence of silicate tetrahedrons formed by Si-O covalent bonds. For example, the Ba2ZnSi2O7 (ε r =8.09, Q×f=26,600GHz, τ f =-51.4ppm / C), Sr2MgSi2O7(ε r =8.3, Q×f=55,000GHz, τ f =-48ppm / C) and BaCo2Si2O7(ε r =9.26, Q×f=31,135GHz, τ f =-92.1ppm / cm). In addition, SrY2Si3O 10 (ε r =9.3, Q×f=64,100GHz, τ f =-31ppm / C) and Li4SrCaSi2O8 (ε r=8.2, Q×f=90,094GHz, τ f =-79.6ppm / C) and other ceramics. These millimeter wave ceramics have a low relative dielectric constant. However, although the dielectric constant of the above-mentioned millimeter wave ceramics can meet the requirements of high-speed information transmission, the other two parameters are not ideal: either the quality factor is not high enough, or the frequency temperature coefficient is too large. In addition, low dielectric materials in the terahertz band are relatively rare. Moreover, in the process of comparing the failure cases of previous millimeter wave dielectric materials, it was found that the dielectric filter often cracked under high and low temperature impact. This is because the high-power operation generates more heat in the actual working process, which will increase the temperature, while the low-power operation generates less heat and lowers the temperature. The temperature change between the two will form a thermal shock effect in the material, or the natural environment temperature changes rapidly in a short period of time. Factors such as factors, due to the fact that the thermal expansion coefficient of most millimeter wave dielectric ceramics is relatively large (between 7-12), and the bending strength of the ceramics is also relatively low, which eventually leads to cracking and peeling of the material surface or instantaneous fracture under the action of thermal stress. Therefore, the core issue is to solve the poor thermal shock resistance of millimeter wave dielectric ceramic materials and to develop low dielectric constant millimeter wave dielectric materials with excellent performance to meet current needs.

[0005] Based on this, the present invention provides a new type of millimeter-wave dielectric ceramic with low dielectric constant, high quality factor, low frequency temperature coefficient, low thermal expansion coefficient, high bending strength and other excellent comprehensive properties. It can adapt to working under extreme temperature conditions and can meet the needs of 5G communication or future 6G communication industry. Summary of the invention

[0006] The object of the present invention is to provide a millimeter wave dielectric ceramic material with high thermal shock resistance and a preparation method thereof. The millimeter wave dielectric ceramic material has the advantages of monoclinic structure, low dielectric constant, high quality factor and high thermal shock resistance.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A millimeter wave dielectric ceramic material with high thermal shock resistance, the chemical formula of the millimeter wave dielectric ceramic material is Yb 2-x A x Si 2-y B y O7, A is La 3+ ,Nd 3+ ,Gd 3+ ,Lu 3+ One of the ions, B is Ti 4+ and Ge 4+ One of the ions, 0<x≤0.12 and 0<y≤0.06.

[0009] Furthermore, the millimeter wave dielectric ceramic material includes SiO2, Yb2O3, A dopant and B dopant, the A dopant is one of La2O3, Nd2O3, Gd2O3, Lu2O3, and the B dopant is one of TiO2 and GeO2.

[0010] Furthermore, the frequency temperature coefficient τ of the millimeter wave dielectric ceramic material f is -13.5±5ppm / ℃, Q×f value is 78600±500GHz, relative dielectric constant ε r It is 6.85~8.35.

[0011] Furthermore, the thermal expansion coefficient of the millimeter wave dielectric ceramic material is 2.8*10 -6 ~3.7*10 -6 / ℃.

[0012] Furthermore, the bending strength of the millimeter wave dielectric ceramic material is 170-285 MPa.

[0013] The fundamental reason for the failure of most filters on the market is the poor thermal shock resistance of millimeter wave dielectric ceramic materials. 3+ 、Nd 3+ , Gd 3+ 、Lu 3+ ;Ti 4+ ,Ge 4+ ) is doped to obtain a chemical formula of Yb 2-x A x Si 2-y B y O7 millimeter wave dielectric ceramic with high thermal shock resistance.

[0014] In order to obtain a millimeter wave dielectric ceramic material with high thermal shock resistance, effectively regulate the phase and stabilize the structure of Yb2Si2O7, the A-site ions must be regulated by replacing rare earth elements of the same valence during the preparation process of the present invention, and the B-site ions must be regulated by elements of the same valence. A is La 3+ ,Nd 3+ ,Gd 3+ ,Lu 3+ One of the trivalent ions, B is Ti 4+ and Ge 4+ions. The present invention also controls the contents of Yb, A, Si, and B ions by comprehensively adjusting the values ​​of x and y to achieve the purpose of adjusting various properties, thereby ensuring that the microscopic morphology of the prepared millimeter wave dielectric ceramic material is highly dense, the grain boundaries are obvious and there are no microcracks, and the phase is stabilized in a monoclinic structure, so that the thermal shock resistance of the ceramic material is improved. The millimeter wave dielectric ceramic of the present invention also has excellent sintering temperature and millimeter wave dielectric properties, and has very excellent performance in the terahertz frequency band (ε r =8.13,Q×f=112,758GHz.), which has great application potential in future 6G communications.

[0015] A method for preparing a millimeter wave dielectric ceramic material with high thermal shock resistance comprises the following steps:

[0016] S1, according to the chemical formula Yb 2-x A x Si 2-y B y Stoichiometric ratio of each cationic element in O7 Weigh SiO2, Yb2O3, A dopant and B dopant and mix them to form a mixture;

[0017] S2, using zirconium dioxide balls as ball milling media, ball milling the mixture according to a mass ratio of mixture: ball milling media: industrial alcohol of 1:(6-8):(3-5) to obtain a primary ball milling material;

[0018] S3, drying and sieving the primary ball mill material to obtain a primary dry powder;

[0019] S4, placing the primary dried powder in an alumina crucible, pre-sintering at 1250-1350° C. to obtain a pre-sintered block, and then crushing the pre-sintered block to obtain a pre-sintered powder;

[0020] S5, using zirconium dioxide balls as ball milling media, ball milling the pre-burned powder according to the mass ratio of pre-burned powder: ball milling media: industrial alcohol of 1: (4-6): (2-3) to obtain secondary ball milling material;

[0021] S6, drying and sieving the secondary ball mill material to obtain secondary dry powder;

[0022] S7, mixing the secondary dried powder and industrial alcohol, pre-pressing at 2 MPa, sealing, and then pressing at a pressure of 200 MPa for 5 to 10 minutes to obtain a green body;

[0023] S8, placing the green body in a sintering furnace, raising the temperature to 1450-1550° C. and sintering for 4-7 hours to obtain the millimeter wave dielectric ceramic material.

[0024] Furthermore, the ball milling time in S2 is 7 to 11 hours; the sieving mesh number in S3 is 150 mesh; and the pre-calcining time in S4 is 5 to 7 hours.

[0025] Furthermore, the ball milling time in S5 is 4 to 7 hours; the sieving mesh number in S6 is 200 mesh; the mass ratio of the secondary dried powder to industrial alcohol in S7 is 1:3; and the heating rate in S8 is 4 to 8°C / min.

[0026] The preparation method of the invention is simple, has high reliability and is easy for industrial production.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The millimeter wave dielectric ceramic material of the present invention has excellent millimeter wave dielectric properties, and its densification temperature occurs between 1250 and 1350° C., and then high-density sintering is completed at a temperature of 1450 to 1550° C.

[0029] 2. In the present invention, the content of Yb, A, Si, and B ions is controlled by adjusting the values ​​of x and y to stabilize the physical phase of the Yb2Si2O7 ceramic and obtain high thermal shock resistance, and finally achieve the purpose of continuous operation under extreme temperature conditions. The millimeter wave dielectric ceramic of the present invention has obvious advantages in thermal shock resistance, can effectively avoid special situations such as cracking and failure, and can meet the application requirements of modern millimeter wave devices and future 6G communications.

[0030] 3. The millimeter wave dielectric ceramic material of the present invention does not contain volatile toxic metals such as Pb and Cd, and can be widely used in millimeter wave devices such as dielectric resonators, filters, oscillators, etc. in satellite communications. It is green, environmentally friendly and pollution-free, and meets the standard requirements of the European Community's directive on the restriction of the use of certain hazardous substances in electrical and electronic equipment and the recycling and treatment management regulations.

[0031] 4. The raw materials for preparing the millimeter wave dielectric ceramic material of the present invention are in sufficient supply and relatively cheap, making it possible to produce high-performance millimeter wave ceramics at low cost, and thus having important industrial application value. Moreover, the sintering temperature of the millimeter wave dielectric ceramic material of the present invention is 1450-1550°C, with a wide sintering temperature range and good process adaptability.

[0032] 5. The raw materials used in the formula of the present invention are simple silicates and oxides, which do not require additional process synthesis, and are completely superior to raw materials that need to be synthesized separately. The two-time ball milling process is used to achieve material particle size control. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the XRD analysis result of the millimeter wave dielectric ceramic material prepared in Example 3 of the present invention.

[0034] Figure 2 This is a scanning transmission electron microscope TEM image of the millimeter wave dielectric ceramic material prepared in Example 5 of the present invention.

[0035] Figure 3 This is a scanning electron microscope (SEM) image of the millimeter wave dielectric ceramic material prepared in Example 8 of the present invention. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] As a preferred embodiment of the present invention, the chemical formula of a millimeter wave dielectric ceramic material with high thermal shock resistance disclosed in this embodiment is Yb 1.97 La 0.03 Si 1.97 Ti 0.03 O7, that is, the A dopant is La2O3, the B dopant is TiO2, x=0.03, y=0.03.

[0039] According to the chemical formula Yb 1.97 La 0.03 Si 1.97 Ti 0.03 The stoichiometric ratios of the cationic elements in O7 are shown in Table 1 below, in weight percentages of SiO2, Yb2O3, La2O3 and TiO2.

[0040] Table 1

[0041] Material Mass percentage / % <![CDATA[SiO2]]> 75.56 <![CDATA[Yb2O3]]> 23 <![CDATA[La2O3]]> 0.95 <![CDATA[TiO2]]> 0.49

[0042] The preparation method of the millimeter wave dielectric ceramic material in this embodiment is as follows:

[0043] S1. Weigh SiO2, Yb2O3, La2O3 and TiO2 according to the mass percentage in Table 1 and mix them to form a mixture;

[0044] S2, using zirconium dioxide balls as ball milling media, ball milling the mixture for 7 hours at a mass ratio of mixture: ball milling media: industrial alcohol of 1:6:3 to obtain a primary ball milling material;

[0045] S3, drying the primary ball mill material at 70°C and passing it through a 150-mesh sieve to obtain a primary dry powder;

[0046] S4, placing the primary dried powder in an alumina crucible, pre-burning at 1260° C. for 5 hours to obtain a pre-burned block, and then crushing the pre-burned block to obtain a pre-burned powder;

[0047] S5, using zirconium dioxide balls as ball milling media, ball milling the pre-calcined powder for 7 hours according to the mass ratio of pre-calcined powder: ball milling media: industrial alcohol of 1:6:3 to obtain secondary ball milling material;

[0048] S6, drying the secondary ball mill material at 70°C and passing it through a 200-mesh sieve to obtain a secondary dry powder;

[0049] S7, mixing the secondary dried powder and industrial alcohol in a mass ratio of 1:3, pre-pressing the mixture at 2 MPa, sealing the mixture, and then pressing the mixture at a pressure of 200 MPa for 10 min to obtain a green body;

[0050] S8, placing the green body in a sintering furnace, heating it to 1460°C and sintering it for 6 hours to obtain the millimeter wave dielectric ceramic material Yb 1.97 La 0.03 Si 1.97 Ti 0.03 O7.

[0051] Example 2

[0052] As a preferred embodiment of the present invention, the chemical formula of a millimeter wave dielectric ceramic material with high thermal shock resistance disclosed in this embodiment is Yb 1.94 Nd 0.06 Si 1.97 Ti 0.03 O7, that is, the A dopant is Nd2O3, the B dopant is TiO2, x=0.06, y=0.03.

[0053] According to the chemical formula Yb 1.94 Nd 0.06 Si 1.97 Ti 0.03 The stoichiometric ratios of the cationic elements in O7 are shown in Table 2 below, in terms of the mass percentages of SiO2, Yb2O3, Nd2O3 and TiO2.

[0054] Table 2

[0055] Material Mass percentage / % <![CDATA[SiO2]]> 74.52 <![CDATA[Yb2O3]]> 23.05 <![CDATA[Nd2O3]]> 1.96 <![CDATA[TiO2]]> 0.47

[0056] The preparation method of the millimeter wave dielectric ceramic material in this embodiment is as follows:

[0057] S1. Weigh SiO2, Yb2O3, Nd2O3 and TiO2 according to the mass percentage in Table 2 and mix them to form a mixture;

[0058] S2, using zirconium dioxide balls as ball milling media, ball milling the mixture for 7 hours at a mass ratio of mixture: ball milling media: industrial alcohol of 1:6:3 to obtain a primary ball milling material;

[0059] S3, drying the primary ball mill material at 70°C and passing it through a 150-mesh sieve to obtain a primary dry powder;

[0060] S4, placing the once dried powder in an alumina crucible, pre-burning at 1295° C. for 3 hours to obtain a pre-burned block, and then crushing the pre-burned block to obtain a pre-burned powder;

[0061] S5, using zirconium dioxide balls as ball milling media, ball milling the pre-calcined powder for 7 hours according to the mass ratio of pre-calcined powder: ball milling media: industrial alcohol of 1:6:3 to obtain secondary ball milling material;

[0062] S6, drying the secondary ball mill material at 70°C and passing it through a 200-mesh sieve to obtain a secondary dry powder;

[0063] S7, mixing the secondary dried powder and industrial alcohol in a mass ratio of 1:3, pre-pressing the mixture at 2 MPa, sealing the mixture, and then pressing the mixture at a pressure of 200 MPa for 8 min to obtain a green body;

[0064] S8, placing the green body in a sintering furnace, heating to 1495°C and sintering for 6 hours to obtain the millimeter wave dielectric ceramic material Yb 1.94 Nd 0.06 Si 1.97 Ti 0.03 O7.

[0065] Example 3

[0066] As a preferred embodiment of the present invention, the chemical formula of a millimeter wave dielectric ceramic material with high thermal shock resistance disclosed in this embodiment is Yb 1.91 G 0.09 Si 1.97 Ti 0.03 O7, that is, the A dopant is Gd2O3, the B dopant is TiO2, x=0.09, y=0.03.

[0067] According to the chemical formula Yb 1.91 G 0.09 Si 1.97 Ti 0.03 The stoichiometric ratios of the cationic elements in O7 are shown in Table 3 below, in terms of the mass percentages of SiO2, Yb2O3, Gd2O3 and TiO2.

[0068] Table 3

[0069] Material Mass percentage / % <![CDATA[SiO2]]> 73.33 <![CDATA[Yb2O3]]> 23.04 <![CDATA[Gd2O3]]> 3.16 <![CDATA[TiO2]]> 0.47

[0070] The preparation method of the millimeter wave dielectric ceramic material in this embodiment is as follows:

[0071] S1. Weigh SiO2, Yb2O3, Gd2O3 and TiO2 according to the mass percentage in Table 3 and mix them to form a mixture;

[0072] S2, using zirconium dioxide balls as ball milling media, ball milling the mixture for 7 hours at a mass ratio of mixture: ball milling media: industrial alcohol of 1:6:3 to obtain a primary ball milling material;

[0073] S3, drying the primary ball mill material at 70°C and passing it through a 150-mesh sieve to obtain a primary dry powder;

[0074] S4, placing the once dried powder in an alumina crucible, pre-burning at 1250° C. for 3 hours to obtain a pre-burned block, and then crushing the pre-burned block to obtain a pre-burned powder;

[0075] S5, using zirconium dioxide balls as ball milling media, ball milling the pre-calcined powder for 7 hours according to the mass ratio of pre-calcined powder: ball milling media: industrial alcohol of 1:6:3 to obtain secondary ball milling material;

[0076] S6, drying the secondary ball mill material at 70°C and passing it through a 200-mesh sieve to obtain a secondary dry powder;

[0077] S7, mixing the secondary dried powder and industrial alcohol in a mass ratio of 1:3, pre-pressing the mixture at 2 MPa, sealing the mixture, and then pressing the mixture at a pressure of 200 MPa for 5 min to obtain a green body;

[0078] S8, placing the green body in a sintering furnace, heating it to 1470°C and sintering it for 6 hours to obtain the millimeter wave dielectric ceramic material Yb 1.91 G 0.09 Si 1.97 Ti 0.03 O7.

[0079] Example 4

[0080] As a preferred embodiment of the present invention, the chemical formula of a millimeter wave dielectric ceramic material with high thermal shock resistance disclosed in this embodiment is Yb 1.88 Lu 0.12 Si 1.97 Ti 0.03 O7, that is, the A dopant is Lu2O3, the B dopant is TiO2, x=0.12, y=0.03.

[0081] According to the chemical formula Yb 1.88 Lu 0.12 Si 1.97 Ti 0.03The stoichiometric ratios of the cationic elements in O7 are shown in Table 4 below, in terms of the mass percentages of SiO2, Yb2O3, Lu2O3 and TiO2.

[0082] Table 4

[0083] Material Mass percentage / % <![CDATA[SiO2]]> 71.94 <![CDATA[Yb2O3]]> 22.96 <![CDATA[Lu2O3]]> 4.17 <![CDATA[TiO2]]> 0.93

[0084] The preparation method of the millimeter wave dielectric ceramic material in this embodiment is as follows:

[0085] S1. Weigh SiO2, Yb2O3, Lu2O3 and TiO2 according to the mass percentage in Table 4 and mix them to form a mixture;

[0086] S2, using zirconium dioxide balls as ball milling media, ball milling the mixture for 7 hours at a mass ratio of mixture: ball milling media: industrial alcohol of 1:6:3 to obtain a primary ball milling material;

[0087] S3, drying the primary ball mill material at 70°C and passing it through a 150-mesh sieve to obtain a primary dry powder;

[0088] S4, placing the once dried powder in an alumina crucible, pre-burning at 1260° C. for 3 hours to obtain a pre-burned block, and then crushing the pre-burned block to obtain a pre-burned powder;

[0089] S5, using zirconium dioxide balls as ball milling media, ball milling the pre-calcined powder for 7 hours according to the mass ratio of pre-calcined powder: ball milling media: industrial alcohol of 1:6:3 to obtain secondary ball milling material;

[0090] S6, drying the secondary ball mill material at 70°C and passing it through a 200-mesh sieve to obtain a secondary dry powder;

[0091] S7, mixing the secondary dried powder and industrial alcohol in a mass ratio of 1:3, pre-pressing the mixture at 2 MPa, sealing the mixture, and then pressing the mixture at a pressure of 200 MPa for 10 min to obtain a green body;

[0092] S8, placing the green body in a sintering furnace, heating it to 1460°C and sintering it for 6 hours to obtain the millimeter wave dielectric ceramic material Yb 1.88 Lu 0.12 Si 1.97 Ti 0.03 O7.

[0093] Example 5

[0094] As a preferred embodiment of the present invention, the chemical formula of a millimeter wave dielectric ceramic material with high thermal shock resistance disclosed in this embodiment is Yb 1.97 La 0.03 Si 1.94 Ge 0.06O7, that is, the A dopant is La2O3, the B dopant is GeO2, x=0.03, y=0.06.

[0095] According to the chemical formula Yb 1.97 La 0.03 Si 1.94 Ge 0.06 The stoichiometric ratios of the cationic elements in O7 are shown in Table 5 below, in terms of the mass percentages of SiO2, Yb2O3, La2O3 and GeO2.

[0096] Table 5

[0097] Material Mass percentage / % <![CDATA[SiO2]]> 75.26 <![CDATA[Yb2O3]]> 22.57 <![CDATA[La2O3]]> 0.95 <![CDATA[GeO2]]> 1.22

[0098] The preparation method of the millimeter wave dielectric ceramic material in this embodiment is as follows:

[0099] S1. Weigh SiO2, Yb2O3, La2O3 and GeO2 according to the mass percentage in Table 5 and mix them to form a mixture;

[0100] S2, using zirconium dioxide balls as ball milling media, ball milling the mixture for 7 hours at a mass ratio of mixture: ball milling media: industrial alcohol of 1:6:3 to obtain a primary ball milling material;

[0101] S3, drying the primary ball mill material at 70°C and passing it through a 150-mesh sieve to obtain a primary dry powder;

[0102] S4, placing the primary dried powder in an alumina crucible, pre-burning at 1250° C. for 3 hours to obtain a pre-burned block, and then crushing the pre-burned block to obtain a pre-burned powder;

[0103] S5, using zirconium dioxide balls as ball milling media, ball milling the pre-calcined powder for 7 hours according to the mass ratio of pre-calcined powder: ball milling media: industrial alcohol of 1:6:3 to obtain secondary ball milling material;

[0104] S6, drying the secondary ball mill material at 70°C and passing it through a 200-mesh sieve to obtain a secondary dry powder;

[0105] S7, mixing the secondary dried powder and industrial alcohol in a mass ratio of 1:3, pre-pressing the mixture at 2 MPa, sealing the mixture, and then pressing the mixture at a pressure of 200 MPa for 8 min to obtain a green body;

[0106] S8, placing the green body in a sintering furnace, heating it to 1500°C and sintering it for 6 hours to obtain the millimeter wave dielectric ceramic material Yb 1.97 La 0.03 Si 1.94 Ge 0.06 O7.

[0107] Example 6

[0108] As a preferred embodiment of the present invention, the chemical formula of a millimeter wave dielectric ceramic material with high thermal shock resistance disclosed in this embodiment is Yb 1.94 Nd 0.06 Si 1.94 Ge 0.06 O7, that is, the A dopant is Nd2O3, the B dopant is GeO2, x=0.06, y=0.06.

[0109] According to the chemical formula Yb 1.94 Nd 0.06 Si 1.94 Ge 0.06 The stoichiometric ratios of the cationic elements in O7 are shown in Table 6 below, in weight percentages of SiO2, Yb2O3, Nd2O3 and GeO2.

[0110] Table 6

[0111] Material Mass percentage / % <![CDATA[SiO2]]> 74.22 <![CDATA[Yb2O3]]> 22.60 <![CDATA[Nd2O3]]> 1.96 <![CDATA[GeO2]]> 1.22

[0112] The preparation method of the millimeter wave dielectric ceramic material in this embodiment is as follows:

[0113] S1. Weigh SiO2, Yb2O3, Nd2O3 and GeO2 according to the mass percentage in Table 6 and mix them to form a mixture;

[0114] S2, using zirconium dioxide balls as ball milling media, ball milling the mixture for 7 hours at a mass ratio of mixture: ball milling media: industrial alcohol of 1:6:3 to obtain a primary ball milling material;

[0115] S3, drying the primary ball mill material at 70°C and passing it through a 150-mesh sieve to obtain a primary dry powder;

[0116] S4, placing the primary dried powder in an alumina crucible, pre-burning at 1340° C. for 3 hours to obtain a pre-burned block, and then crushing the pre-burned block to obtain a pre-burned powder;

[0117] S5, using zirconium dioxide balls as ball milling media, ball milling the pre-calcined powder for 7 hours according to the mass ratio of pre-calcined powder: ball milling media: industrial alcohol of 1:6:3 to obtain secondary ball milling material;

[0118] S6, drying the secondary ball mill material at 70°C and passing it through a 200-mesh sieve to obtain a secondary dry powder;

[0119] S7, mixing the secondary dried powder and industrial alcohol in a mass ratio of 1:3, pre-pressing the mixture at 2 MPa, sealing the mixture, and then pressing the mixture at a pressure of 200 MPa for 7 minutes to obtain a green body;

[0120] S8, placing the green body in a sintering furnace, heating it to 1540°C and sintering it for 6 hours to obtain the millimeter wave dielectric ceramic material Yb 1.94 Nd 0.06 Si 1.94 Ge 0.06 O7.

[0121] Example 7

[0122] As a preferred embodiment of the present invention, the chemical formula of a millimeter wave dielectric ceramic material with high thermal shock resistance disclosed in this embodiment is Yb 1.91 G 0.09 Si 1.94 Ge 0.06 O7, that is, the A dopant is Gd2O3, the B dopant is GeO2, x=0.09, y=0.06.

[0123] According to the chemical formula Yb 1.91 G 0.09 Si 1.94 Ge 0.06 The stoichiometric ratios of the cationic elements in O7 are shown in Table 7 below, in weight percentages of SiO2, Yb2O3, Gd2O3 and GeO2.

[0124] Table 7

[0125] Material Mass percentage / % <![CDATA[SiO2]]> 73.03 <![CDATA[Yb2O3]]> 22.59 <![CDATA[Gd2O3]]> 3.16 <![CDATA[GeO2]]> 1.22

[0126] The preparation method of the millimeter wave dielectric ceramic material in this embodiment is as follows:

[0127] S1. Weigh SiO2, Yb2O3, Gd2O3 and GeO2 according to the mass percentage in Table 7 and mix them to form a mixture;

[0128] S2, using zirconium dioxide balls as ball milling media, ball milling the mixture for 7 hours at a mass ratio of mixture: ball milling media: industrial alcohol of 1:6:3 to obtain a primary ball milling material;

[0129] S3, drying the primary ball mill material at 70°C and passing it through a 150-mesh sieve to obtain a primary dry powder;

[0130] S4, placing the primary dried powder in an alumina crucible, pre-burning at 1290° C. for 3 hours to obtain a pre-burned block, and then crushing the pre-burned block to obtain a pre-burned powder;

[0131] S5, using zirconium dioxide balls as ball milling media, ball milling the pre-calcined powder for 7 hours according to the mass ratio of pre-calcined powder: ball milling media: industrial alcohol of 1:6:3 to obtain secondary ball milling material;

[0132] S6, drying the secondary ball mill material at 70°C and passing it through a 200-mesh sieve to obtain a secondary dry powder;

[0133] S7, mixing the secondary dried powder and industrial alcohol in a mass ratio of 1:3, pre-pressing the mixture at 2 MPa, sealing the mixture, and then pressing the mixture at a pressure of 200 MPa for 7 minutes to obtain a green body;

[0134] S8, placing the green body in a sintering furnace, heating to 1490°C and sintering for 6 hours to obtain the millimeter wave dielectric ceramic material Yb 1.91 G 0.09 Si 1.94 Ge 0.06 O7.

[0135] Example 8

[0136] As a preferred embodiment of the present invention, the chemical formula of a millimeter wave dielectric ceramic material with high thermal shock resistance disclosed in this embodiment is Yb 1.88 Lu 0.12 Si 1.94 Ge 0.06 O7, that is, the A dopant is Lu2O3, the B dopant is GeO2, x=0.12, y=0.06.

[0137] According to the chemical formula Yb 1.88 Lu 0.12 Si 1.94 Ge 0.06 The stoichiometric ratios of the cationic elements in O7 are shown in Table 8 below, in terms of the mass percentages of SiO2, Yb2O3, Lu2O3 and GeO2.

[0138] Table 8

[0139] Material Mass percentage / % <![CDATA[SiO2]]> 71.64 <![CDATA[Yb2O3]]> 22.52 <![CDATA[Lu2O3]]> 4.62 <![CDATA[GeO2]]> 1.22

[0140] The preparation method of the millimeter wave dielectric ceramic material in this embodiment is as follows:

[0141] S1. Weigh SiO2, Yb2O3, Lu2O3 and GeO2 according to the mass percentage in Table 8 and mix them to form a mixture;

[0142] S2, using zirconium dioxide balls as ball milling media, ball milling the mixture for 7 hours at a mass ratio of mixture: ball milling media: industrial alcohol of 1:6:3 to obtain a primary ball milling material;

[0143] S3, drying the primary ball mill material at 70°C and passing it through a 150-mesh sieve to obtain a primary dry powder;

[0144] S4, placing the once dried powder in an alumina crucible, pre-burning at 1275° C. for 3 hours to obtain a pre-burned block, and then crushing the pre-burned block to obtain a pre-burned powder;

[0145] S5, using zirconium dioxide balls as ball milling media, ball milling the pre-calcined powder for 7 hours according to the mass ratio of pre-calcined powder: ball milling media: industrial alcohol of 1:6:3 to obtain secondary ball milling material;

[0146] S6, drying the secondary ball mill material at 70°C and passing it through a 200-mesh sieve to obtain a secondary dry powder;

[0147] S7, mixing the secondary dried powder and industrial alcohol in a mass ratio of 1:3, pre-pressing the mixture at 2 MPa, sealing the mixture, and then pressing the mixture at a pressure of 200 MPa for 7 minutes to obtain a green body;

[0148] S8, placing the green body in a sintering furnace, heating to 1475°C and sintering for 6 hours to obtain the millimeter wave dielectric ceramic material Yb 1.88 Lu 0.12 Si 1.94 Ge 0.06 O7.

[0149] The millimeter wave dielectric properties of the millimeter wave dielectric ceramic materials of Examples 1 to 8 were tested, and the test results are shown in Table 9.

[0150] Table 9

[0151]

[0152] As shown in Table 9, the relative dielectric constant εr of the millimeter wave dielectric ceramic material prepared by the present invention is between 6.85 and 8.35, the Q×f value is 78600±500GHz, and the frequency temperature coefficient τ f -13.5±5ppm / ℃, thermal expansion coefficient is 2.8~3.7*10 -6 / ℃, the flexural strength is between 170 and 285MPa, and it has excellent sintering temperature and millimeter wave dielectric properties.

[0153] Figure 1 This is the XRD analysis result of the millimeter wave dielectric ceramic material prepared in Example 3. Figure 1 It can be seen that there is no secondary phase in the prepared material, indicating that the material crystallizes as a single phase over the entire temperature range, specifically identified as a monoclinic structure with a space group of C2 / m.

[0154] Figure 2 This is a scanning transmission electron microscope TEM image of the millimeter wave dielectric ceramic material prepared in Example 5. Figure 2 This indicates that the monoclinic structure of the ceramic material has been successfully synthesized, and the space group is determined to be C2 / m, which is consistent with the XRD observation results.

[0155] Figure 3 : is a scanning electron microscope (SEM) image of the millimeter wave dielectric ceramic material prepared in Example 8. Figure 3 It can be concluded that the ceramic material of the present invention has a highly dense microstructure, distinct grain boundaries and no microcracks.

[0156] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention to illustrate the technical solutions of the present invention, rather than limiting them, and certainly not limiting the patent scope of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. In other words, any changes or modifications made to the main design concept and spirit of the present invention that have no substantive significance, and the technical problems they solve are still consistent with the present invention, should be included in the protection scope of the present invention. In addition, the direct or indirect application of the technical solutions of the present invention in other related technical fields is also included in the patent protection scope of the present invention.

Claims

1. A millimeter wave dielectric ceramic material with high thermal shock resistance, characterized in that: The chemical formula of the millimeter wave dielectric ceramic material is Yb 2-x A x Si 2-y B y O7, A is La 3+ ,Nd 3+ ,Gd 3+ ,Lu 3+ One of the ions, B is Ti 4+ and Ge 4+ One of the ions, 0<x≤0.12 and 0<y≤0.

06.

2. The millimeter wave dielectric ceramic material with high thermal shock resistance according to claim 1, characterized in that: The millimeter wave dielectric ceramic material includes SiO2, Yb2O3, A dopant and B dopant, wherein the A dopant is one of La2O3, Nd2O3, Gd2O3 and Lu2O3, and the B dopant is one of TiO2 and GeO2.

3. The millimeter wave dielectric ceramic material with high thermal shock resistance according to claim 1, characterized in that: The frequency temperature coefficient of the millimeter wave dielectric ceramic material is -13.5±5ppm / °C, the Q×f value is 78600±500GHz, and the relative dielectric constant is 6.85-8.

35.

4. The millimeter wave dielectric ceramic material with high thermal shock resistance according to claim 1, characterized in that: The thermal expansion coefficient of the millimeter wave dielectric ceramic material is 2.8*10 -6 ~3.7*10 -6 / ℃.

5. The millimeter wave dielectric ceramic material with high thermal shock resistance according to claim 1, characterized in that: The bending strength of the millimeter wave dielectric ceramic material is 170-285 MPa.

6. The method for preparing a millimeter wave dielectric ceramic material with high thermal shock resistance according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1, according to the chemical formula Yb 2-x A x Si 2-y B y Stoichiometric ratio of each cationic element in O7 Weigh SiO2, Yb2O3, A dopant and B dopant and mix them to form a mixture; S2, using zirconium dioxide balls as ball milling media, ball milling the mixture according to a mass ratio of mixture: ball milling media: industrial alcohol of 1:(6-8):(3-5) to obtain a primary ball milling material; S3, drying and sieving the primary ball mill material to obtain a primary dry powder; S4, placing the primary dried powder in an alumina crucible, pre-sintering at 1250-1350° C. to obtain a pre-sintered block, and then crushing the pre-sintered block to obtain a pre-sintered powder; S5, using zirconium dioxide balls as ball milling media, ball milling the pre-burned powder according to the mass ratio of pre-burned powder: ball milling media: industrial alcohol of 1: (4-6): (2-3) to obtain secondary ball milling material; S6, drying and sieving the secondary ball mill material to obtain secondary dry powder; S7, mixing the secondary dried powder and industrial alcohol, pre-pressing at 2 MPa, sealing, and then pressing at a pressure of 200 MPa for 5 to 10 minutes to obtain a green body; S8, placing the green body in a sintering furnace, raising the temperature to 1450-1550° C. and sintering for 4-7 hours to obtain the millimeter wave dielectric ceramic material.

7. According to the method for preparing a millimeter wave dielectric ceramic material with high thermal shock resistance as described in claim 6, the ball milling time in S2 is 7 to 11 hours; the sieving mesh number in S3 is 150 mesh; and the pre-firing time in S4 is 5 to 7 hours.

8. According to the method for preparing a millimeter wave dielectric ceramic material with high thermal shock resistance as described in claim 6, the ball milling time in S5 is 4 to 7 hours; the sieving mesh number in S6 is 200 mesh; the mass ratio of secondary dried powder to industrial alcohol in S7 is 1:3; and the heating rate in S8 is 4 to 8°C / min.

Images