Low-temperature glass-ceramic material for microwave electronics
The optimized composition of low-temperature glass-ceramic materials with specific oxide ratios and α-modification alumina ceramics addresses the limitations of existing materials, enhancing dielectric and mechanical properties for microwave equipment use.
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Patents
- Current Assignee / Owner
- AKTSIONERNOE OBSHCHESTVO NAUCHNO-PROIZVODSTVENNOE PREDPRIYATIE ISTOK IMENI SHOKINA
- Filing Date
- 2025-06-05
- Publication Date
- 2026-07-07
AI Technical Summary
Existing low-temperature glass-ceramic materials for microwave electronic equipment face challenges in achieving optimal electrophysical parameters such as low tangent of the dielectric loss angle, low microwave losses, and high dielectric constant, which limits their use in a wide range of operating frequencies above 10 GHz, while also avoiding the use of lead oxide to prevent increased microwave losses.
A low-temperature glass-ceramic material composed of specific ratios of oxides including aluminum (Al2O3), silicon (SiO2), boron (B2O3), calcium (CaO), magnesium (MgO), strontium (SrO), copper (Cu2O), zirconium (ZrO2), and zinc (ZnO) with α-modification alumina ceramics (α-Al2O3), optimized for particle size and composition to enhance dielectric properties and mechanical strength.
The solution achieves a reduction in dielectric loss tangent, maintains required dielectric constant values across a wide frequency range, reduces microwave losses, and increases mechanical strength, expanding the functional capabilities of the material for microwave electronic equipment.
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Abstract
Description
[0001] The invention relates to various technological processes, namely low-temperature glass-ceramic materials, and can be used in wide-range microwave radio and electronic equipment.
[0002] Main electrophysical parameters of low-temperature glass-ceramic material for microwave electronic equipment:
[0003] - low tangent of the dielectric loss angle and accordingly
[0004] - low microwave loss;
[0005] - given - required dielectric constant, ε;
[0006] - high specific volume electrical resistance, ρ (Ohm×m);
[0007] - material density;
[0008] - compatibility of temperature coefficients of linear expansion (TCLE), (1 / deg);
[0009] - high density of wiring packing;
[0010] - high speed microwave signal transmission;
[0011] - operating frequency range, GHz.
[0012] The latter is especially relevant and important at the present time.
[0013] A sintered dielectric material is known which, before sintering, contains a solids portion containing 10-99 wt.% of quartz powder having a D-50 particle size of 0.5-30 μm, and 1-90 wt.% of a glass component containing
[0014] 50-90 mol.% SiO2,
[0015] 0.1-35 mol. %B2O3,
[0016] 0.1-25 mol.% Al2O3,
[0017] 0.1-10 mol.% K2O,
[0018] 0.1-10 mol. %Na2O,
[0019] 0.1-20 mol. % Li2O,
[0020] 0.1-30 mol.% F, and
[0021] the total amount of Li2O+Na2O+K2O is 0.1-30 mol.% of the glass component,
[0022] wherein the sintered dielectric material has a dielectric constant of less than 8 and a quality factor Q of more than 500 when sintered at a temperature below 1100°C.
[0023] [Patent No. 2701611 of the Russian Federation. Low-K dielectric compositions for use at high frequencies / GLEASON Godi (US) et al. / / Bull. - 2019 - No. 28].
[0024] This glass-ceramic material provides values of the dielectric constant K (hereinafter referred to as permittivity, ε) less than 8 and the quality factor Q greater than 500 at 10-30 GHz.
[0025] Such high electrophysical parameters should ensure its use in a wide range of wavelengths, both high-frequency and ultra-high-frequency.
[0026] However, this is practically difficult to implement, from the point of view of manufacturing this glass-ceramic material.
[0027] A low-temperature glass-ceramic material for electronic equipment is known, containing low-temperature glass and aluminum oxide at a given ratio, wherein the low-temperature glass includes oxides of silicon, aluminum, boron, barium, lead, sodium and potassium, which is used for the purpose of creating a low-temperature glass-ceramic material for electronic equipment in the high-frequency and ultra-high-frequency range of wavelengths.
[0028] The said material contains low-temperature non-crystallizing glass and aluminum oxide in a weight ratio of (1.0-1.6):(1.0-0.4), respectively, and the low-temperature non-crystallizing glass additionally contains cobalt oxide and nickel oxide in the following ratio of components, wt. %:
[0029] silicon oxide (SiO2) 32,5-64 aluminum oxide (Al2O3) 1,8-5 boron oxide (B2O3) 8-14 lead oxide (PbO) 0,1-5 barium oxide (BaO) 21,5-39 cobalt oxide (CoO) 0,25-0,55 nickel oxide (NiO) 0,05 sodium oxide (Na2O) 2,4 potassium oxide (K2O) 1,6
[0030] [Patent No. 2753522 of the Russian Federation. LOW-TEMPERATURE GLASS-CERAMIC MATERIAL FOR ELECTRONIC EQUIPMENT / D.A. Pashkov et al. / / Bulletin - 2021 - No. 23].
[0031] This low-temperature glass-ceramic material, like the first analogue, ensures its use in high-frequency and ultra-high-frequency wavelength ranges.
[0032] However, the presence of lead oxide (PbO) component in low-temperature glass-ceramic material for microwave electronic equipment is not desirable, as it leads to an increase in microwave losses in the frequency range above 10 GHz.
[0033] A low-temperature glass-ceramic material is known, containing low-temperature lead-free crystallizing glass and ceramics at a given ratio, wherein the low-temperature crystallizing glass is made on the basis of oxides of chemical elements, which, in order to ensure a stable approximation of electrical insulating properties, dielectric constant "ε", temperature coefficient of linear expansion "TCLE" and mechanical strength "σ изг. » to ceramic requirements due to complete sitallization and (or) cementation of low-temperature crystallizing glass - matrix with alumina ceramics - filler.
[0034] The low-temperature glass-ceramic material contains low-temperature crystallizing glass and alumina ceramics in a ratio of (1.4-1.0):(0.6-1.0), respectively, and the low-temperature crystallizing glass additionally contains chromium oxide in the following ratio of components, wt. %:
[0035] silicon oxide (SiO2) 20-34 barium oxide (BaO) 34-40 boron oxide (B2O3) 23-26 calcium oxide (CaO) 1-10 tin oxide (SnO2) 1-10
[0036] Over 100%
[0037] chromium oxide (Cr2O3) 2-5 aluminum oxide (Al2O3) 5-10
[0038] [Patent No. 2712840 of the Russian Federation. Low-temperature glass-ceramic material and method for its manufacture / E.I. Chelnokov / / Bulletin. - 2020 - No. 4].
[0039] A low-temperature glass-ceramic material is known containing low-temperature crystallizing glass and ceramics in a ratio of (1.2-1.0):(0.8-1.0), respectively, and the low-temperature crystallizing glass additionally contains zinc oxide in the following ratio of components, wt. %:
[0040] Aluminum oxide (Al2O3) 2,0-8,0 Silicon oxide (SiO2) 17,0-7,0 Boron oxide (B2O3) 3,2-12,5 Calcium oxide (CaO) 22,0-11,0 Magnesium oxide (MgO) 4,2-3,5 Strontium Oxide (SrO) 0,4-2,5 Copper oxide (Cu2O) 0,4-1,5 Zirconium oxide (ZrO) 1,8-0,5 Zinc oxide (ZnO) 9,0-3,5 Ceramics Rest
[0041] [Patent No. 2410358 RF. Low-temperature glass-ceramic material / S.N. Sytilin et al. / / Bulletin - 2009 - No. 3] - prototype.
[0042] The low-temperature glass-ceramic material of the third analogue, as well as the prototype analogue, are close in qualitative and quantitative composition and have fairly high electrophysical parameters in general.
[0043] However, this level is relative to individual electrophysical parameters, namely:
[0044] - tangent of the dielectric loss angle and accordingly
[0045] - microwave losses,
[0046] - dielectric constant, ε - is not sufficient, since it does not provide the possibility of using these low-temperature glass-ceramic materials in microwave electronic equipment of a wide range of operating frequencies, more than 10 GHz.
[0047] The technical result is an improvement in the electrophysical parameters - a reduction in the tangent of the dielectric loss angle, ensuring the specified - required values of the dielectric constant (in a wide range of operating frequencies), and, accordingly, a reduction in microwave losses, and an expansion of the functional capabilities from the point of view of the device for using microwave electronic equipment, an increase in mechanical strength while maintaining other electrophysical parameters - high specific volume electrical resistance, ρ, compatibility of temperature coefficients of linear expansion (TCLE), high density.
[0048] The specified technical result is achieved by the claimed low-temperature glass-ceramic material for microwave electronic equipment, containing low-temperature crystallizing glass based on oxides of chemical elements - aluminum (Al2O3), silicon (SiO2), boron (B2O3), calcium (CaO), magnesium (MgO), strontium (SrO), copper (Cu2O), zirconium (ZrO2), zinc (ZnO) and aluminum oxide ceramics (Al2O3) at a given ratio,
[0049] At the same time
[0050] alumina ceramics (Al2O3) is an α-modification alumina ceramics (α-Al2O3), and the low-temperature glass-ceramic material contains the mentioned components in the following ratio, respectively, by weight%:
[0051] Aluminum oxide (Al2O3) 14,8-15,4 Silicon oxide (SiO2) 26,0-29,0 Boron oxide (B2O3) 17,0-20,0 Calcium oxide (CaO) 20,0-24,0 Magnesium oxide (MgO) 4,2-6,0 Strontium Oxide (SrO) 2,0-3,0 Copper oxide (Cu2O) 0,5-1,0 Zirconium oxide (ZrO2) 0,5-1,0 Zinc oxide (ZnO) 8,0-11,0
[0052] - wherein the low-temperature crystallizing glass and the α-modification alumina ceramics (α-Al2O3) have a ratio of (0.82-0.88):(1.18-1.12), respectively, the low-temperature crystallizing glass and the α-modification alumina ceramics (α-Al2O3) have an average particle size of (2.4-2.8):(1.5-1.8), respectively.
[0053] Disclosure of the essence of the invention.
[0054] A set of essential features, both restrictive and distinctive parts of the claimed low-temperature glass-ceramic material for microwave electronic equipment, namely when:
[0055] Alumina ceramics (Al2O3) is an α-modification alumina ceramics (α-Al2O3).
[0056] And in total, when the low-temperature glass-ceramic material contains the mentioned components at their stated ratio, respectively, wt.%:
[0057] Aluminum oxide (Al2O3) 14,8-15,4 Silicon oxide (SiO2) 26,0-29,0 Boron oxide (B2O3) 17,0-20,0 Calcium oxide (CaO) 20,0-24,0 Magnesium oxide (MgO) 4,2-6,0 Strontium Oxide (SrO) 2,0-3,0 Copper oxide (Cu2O) 0,5-1,0 Zirconium oxide (ZrO2) 0,5-1,0 Zinc oxide (ZnO) 8,0-11,0
[0058] And in combination, when low-temperature crystallizing glass and α-modification alumina ceramics (α-Al2O3) have:
[0059] - quantitative ratio (0.82-0.88):(1.18-1.12),
[0060] - each of the mentioned components have an average particle size of (2.4-2.8):(1.5-1.8) respectively.
[0061] This ensures the maximum possible optimization of their mutual, both qualitative and quantitative composition and, as a consequence, the maximum possible optimization of the main electrophysical parameters, namely.
[0062] Firstly, improvement of some electrophysical parameters:
[0063] - reduction of the dielectric loss tangent and, accordingly, reduction of microwave losses;
[0064] - ensuring the specified - required values of dielectric constant (in a wide range of operating frequencies, up to millimeter,
[0065] - significant increase in mechanical strength due to optimization of particle size of each of the mentioned components and, thus, significant reduction of glass phase in low-temperature glass-ceramic material.
[0066] Secondly, while maintaining other electrical parameters:
[0067] - high specific volume electrical resistance, ρ;
[0068] - compatibility of temperature coefficients of linear expansion (TCLE);
[0069] - high density.
[0070] And, as a consequence of the first and second - the expansion of the functional capabilities of the declared low-temperature glass-ceramic material for microwave electronic equipment.
[0071] The qualitative and quantitative composition, and the values of the limits of the latter, declared in the formula of the invention of a low-temperature glass-ceramic material for microwave electronic equipment, are optimal, from the point of view of ensuring the specified technical result, and violation of these limits, both left and right, is not desirable, since it leads to its deterioration, which is confirmed by the data presented in the table.
[0072] Thus, the claimed low-temperature glass-ceramic material for microwave electronic equipment fully ensures the specified technical result - improvement of electrophysical parameters - reduction of the dielectric loss tangent, provision of the specified - required values of permittivity (in a wide range of operating frequencies), and, accordingly, reduction of microwave losses, and expansion of functional capabilities, increase of mechanical strength while maintaining other electrophysical parameters - high specific volume electrical resistance, ρ, compatibility of temperature coefficients of linear expansion (TCLE), high density.
[0073] Examples of specific implementation.
[0074] Example 1.
[0075] The declared low-temperature glass-ceramic material is manufactured according to the technological process of glass-ceramic technology, which provides for the following sequence of technological operations.
[0076] 1. Low-temperature crystallizing glass is prepared based on oxides of aluminum (Al2O3), silicon (SiO2), boron (B2O3), calcium (CaO), magnesium (MgO), strontium (SrO), copper (Cu2O), zirconium (ZrO2), zinc (ZnO) of the “ch”, “chda”, “osch” grade in an amount, by weight. % 14.85, 27.04, 18.19, 21.63, 5.01, 2.46, 0.74, 0.74, 9.34, respectively.
[0077] Mix them using a roller mill (Brand BL-6A).
[0078] Pressed into briquettes and cooked in a chamber electric furnace of the SNOL type with periodic action at a temperature of 1370°C and maintained at this temperature for an hour.
[0079] Next, granulation and subsequent grinding of the granulate are carried out in a planetary mill (Pulverizette-5) and a vibratory mill (VM-2).
[0080] 2. Prepare alumina ceramics of α-modification (α-Al2O3) based on corundum micropowder K-1 TU 23.20.13-001-07593894-2022, by grinding the latter in a vibrating mill (SWECO M-18-5) for 96 hours, in an amount of 59 wt. % (based on the ratio (0.82-0.88): (1.18-1.12) - low-temperature crystallizing glass and alumina ceramics of α-modification (α-Al2O3), respectively).
[0081] At the same time, low-temperature crystallizing glass and alumina ceramics of the α-modification (α-Al2O3) with an average particle size of 2.6:1.6, respectively, are provided under continuous monitoring using the Analisette 22 Microtec XT laser installation.
[0082] 3. Mix the prepared components - low-temperature crystallizing glass and α-modified alumina ceramic powder (α-Al2O3) using a vibratory mill (VM-2).
[0083] From the prepared mixture of powders, a slip is prepared by adding a binder - a solution of polyvinyl butyral in ethyl alcohol, with constant stirring in a ball mill (BL-4A) until a homogeneous, specified viscosity of the slip is obtained.
[0084] 4. The slip is used to produce a tape by casting (HED TSM-401SM), followed by the formation of low-temperature glass-ceramic material samples of a given shape by isostatic pressing (IL).
[0085] Then, firing is carried out at a temperature of 870°C for 20 minutes.
[0086] The firing process results in the final formation - synthesis of low-temperature glass-ceramic material.
[0087] Examples 2-5.
[0088] Similarly to example 1, samples of low-temperature glass-ceramic material were manufactured, but with different parameters, both those stated in the invention formula (examples 2-3) and those outside it (examples 4-5).
[0089] Example 6 corresponds to the prototype.
[0090] The following were measured on the manufactured samples of low-temperature glass-ceramic material:
[0091] - dielectric loss tangent at a frequency of 10 GHz (RVD stand (waveguide-dielectric resonator);
[0092] - dielectric constant, ε at a frequency of 10 GHz (Resonance method, GOST 8.544-86);
[0093] - coefficient of linear temperature expansion (CLTE) (GOST 71639-2024);
[0094] specific volume electrical resistance (Ohm / cm) (KRPG.25803.00003);
[0095] - mechanical bending strength (MPa) (KRPG.258803.00005);
[0096] - density (g / cm 3 ) (GOST 473.4-81).
[0097] The data are presented in Table 1 (see in the graphic part).
[0098] Table 2 (see in the graphic section) presents the electrophysical and physical parameters of the above-manufactured samples of the claimed low-temperature glass-ceramic material (examples 1-5) and the prototype (example 6), respectively.
[0099] As can be seen from Table 1 and Table 2, the samples of low-temperature glass-ceramic material of qualitative and quantitative composition according to the claimed formula of the invention (examples 1-3) have the following values, respectively:
[0100] - dielectric loss tangent at 10 GHz - 12.4×10 -4 , 12.0×10 -4 , 12.5×10 -4 ;
[0101] - permittivity, ε at a frequency of 10 GHz - 7.0, 7.2, 7.4;
[0102] - thermal coefficient of linear expansion - 69.0×10 7 , 71.0×10 7 , 72.0×10 7 (1 / deg);
[0103] - specific volume electrical resistance, ρ (Ohm×m) - more than 1×10 12 ;
[0104] - density - (2.85, 3.0, 2.9) g / cm 3 ;
[0105] - mechanical bending strength δ ср - (230.0, 250.0, 240.0) MPa.;
[0106] Unlike samples of low-temperature glass-ceramic material of qualitative and quantitative composition outside the scope of the invention formula, as well as the prototype, which have worse values of similar electrophysical parameters.
[0107] Thus, the declared low-temperature glass-ceramic material, in comparison with the prototype, provides:
[0108] - reduction of the dielectric loss tangent by approximately 29 percent and, accordingly, a reduction in microwave losses;
[0109] - ensuring the specified - required values of dielectric constant, ε - 7.2±0.2 in a wide range of operating frequencies (3-35) GHz, the latter is a fairly high result and is extremely relevant and important today;
[0110] - increase in mechanical strength - about 60 percent.
[0111] When saving:
[0112] - specific volume electrical resistance, ρ;
[0113] - compatibility of temperature coefficients of linear expansion (TCLE);
[0114] - high density.
[0115] And, as a consequence, the expansion of the functional capabilities of the declared low-temperature glass-ceramic material for microwave electronic equipment.
Claims
Low-temperature glass-ceramic material for microwave electronic equipment, containing low-temperature crystallizing glass based on oxides of chemical elements - aluminum (Al2O3), silicon (SiO2), boron (B2O3), calcium (CaO), magnesium (MgO), strontium (SrO), copper (Cu2O), zirconium (ZrO2), zinc (ZnO) and aluminum oxide ceramics (Al2O3) in a given ratio, characterized in that alumina ceramics (Al2O3) is an alumina ceramic of the α-modification (α-Al2O3), and the low-temperature glass-ceramic material contains the mentioned components in the following ratio, respectively, wt. %: Aluminum oxide (Al2O3) 14,8-15,4 Silicon oxide (SiO2) 26,0-29,0 Boron oxide (B2O3) 17,0-20,0 Calcium oxide (CaO) 20,0-24,0 Magnesium oxide (MgO 4,2-6,0 Strontium Oxide (SrO) 2,0-3,0 Copper oxide (Cu2O) 0,5-1,0 Zirconium oxide (ZrO2) 0,5-1,0 Zinc oxide (ZnO) 8,0-11,0 - in this case, low-temperature crystallizing glass and alumina ceramics of the α-modification (α-Al2O3) have a ratio of (0.82-0.88):(1.18-1.12), respectively, low-temperature crystallizing glass and alumina ceramics of the α-modification (α-Al2O3) have an average particle size of (2.4-2.8):(1.5-1.8), respectively.