TWI850615B - Multilayer glass ceramic dielectric material, sintered body, method for manufacturing sintered body, and high frequency circuit component - Google Patents

Abstract

The present invention provides a laminated glass ceramic dielectric material, a sintered body and a high frequency circuit component having low dielectric properties and high mechanical strength in a high frequency region above 20 GHz. The laminated glass ceramic dielectric material of the present invention is characterized in that it has a laminated structure in which at least an outer layer, an inner layer and an outer layer are laminated in the order of an outer layer, the outer layer comprises a material having a relative dielectric constant of 5.5 or less at a measured temperature of 25°C and a frequency of 28 GHz after sintering, and the inner layer comprises a material having a thermal expansion coefficient after sintering that becomes higher than the thermal expansion coefficient of the outer layer after sintering.

Description

Multilayer glass ceramic dielectric material, sintered body, method for manufacturing sintered body, and high frequency circuit component

The present invention relates to a laminated glass ceramic dielectric material, a sintered body and a high frequency circuit component having a lower dielectric constant and a higher mechanical strength which are advantageous for signal processing in a high frequency region above 20 GHz.

Alumina ceramics are widely used as wiring boards or circuit components. Alumina ceramics have a relatively high relative dielectric constant of 10, so they have the disadvantage of slow signal processing speed. In addition, since the conductor material must use tungsten with a high melting point, there is also a disadvantage of high conductor loss.

In order to remedy the above shortcomings, glass-ceramic dielectric materials containing glass powder and ceramic powder are being developed, and their sintered bodies are used as dielectric layers. For example, the relative dielectric constant of the sintered body of the glass-ceramic dielectric material using glass powder containing alkaline borosilicate glass is 6 to 8, which is lower than the relative dielectric constant of the alumina ceramic material. In addition, because it can be sintered at a temperature below 1000°C, it has the advantage of being able to be sintered simultaneously with low-melting-point metal materials such as Ag and Cu with low conductor loss, and these can be used as inner conductors (see patent documents 1 and 2). [Prior art document] [Patent document]

[Patent document 1] Japanese Patent No. 11-116272 [Patent document 2] Japanese Patent No. 9-241068 [Patent document 3] Japanese Patent No. 60-136294

[The problem the invention is trying to solve]

However, in recent years, in the field of mobile communication devices represented by 5G (fifth-generation) and local area network communications such as WiFi, the frequency band used is higher, above 20 GHz. In this high-frequency area, there is a strong demand for glass-ceramic dielectric materials to have a further lower dielectric constant.

The transmission loss of electromagnetic waves in electronic circuits is proportional to the product of the square root of the dielectric constant of the circuit substrate, the dielectric loss tangent, and the frequency of the electromagnetic waves. The glass-ceramic dielectric materials disclosed in Patent Documents 1 and 2 have a problem of increased transmission loss because the relative dielectric constant of the sintered body is 6 to 8, which is not low enough compared to the required value. In addition, the mechanical strength of the sintered body of the glass-ceramic dielectric material with a lower dielectric constant is lower, and abnormal conditions such as cracks and crazing have occurred during the process of mounting components on the substrate.

In order to overcome the above problems, it has been proposed to combine a low dielectric constant layer with a high strength layer to achieve both a reduction in transmission loss and a high strength of the substrate (see Patent Document 3).

However, the dielectric material disclosed in Patent Document 3 has the problem of insufficient strength.

The purpose of the present invention is to provide a multilayer glass ceramic dielectric material, a sintered body and a high-frequency circuit component having low dielectric properties and high mechanical strength in the high-frequency region above 20 GHz. [Technical means to solve the problem]

The laminated glass ceramic dielectric material of the present invention is characterized in that it has a laminated structure in which at least an outer layer, an inner layer, and an outer layer are laminated in the order of one another, wherein the outer layer comprises a material having a relative dielectric constant of 5.5 or less when the measured temperature is 25°C and the frequency is 28 GHz after sintering, and the inner layer comprises a material having a thermal expansion coefficient after sintering that is higher than the thermal expansion coefficient of the outer layer after sintering.

Here, the "relative dielectric constant at a measurement temperature of 25°C and a frequency of 28 GHz" is measured by using a sintered body densely sintered at 900°C as a measurement sample. The "thermal expansion coefficient" is an average value measured by using a sintered body densely sintered at 900°C as a measurement sample in a temperature range of 30 to 380°C. In addition, the "inner layer" and the "outer layer" are different materials. Furthermore, the "inner layer" and the "outer layer" are not limited to one layer each, but may be a plurality of layers stacked with substantially the same material. Furthermore, substantially the same material refers to a material whose difference in thermal expansion coefficient after sintering is less than 1 ppm/K. Furthermore, the laminate of substantially the same material will be integrated into a single layer after sintering. The "thermal expansion coefficient" in this case refers to the thermal expansion coefficient of the sintered body of the laminate of substantially the same material sintered densely at 900°C. Furthermore, from the perspective of effectively enjoying the effects of the present invention, it is preferred that there are no heterogeneous layers other than the "inner layer" and the "outer layer", but in the present invention, the situation of having a heterogeneous layer inside the outer layer is not completely excluded.

In addition, in the laminated glass ceramic dielectric material of the present invention, the relative dielectric constant of the outer layer after sintering at a temperature of 25°C and a frequency of 28 GHz is measured to be less than 5.5. Thus, the lower dielectric properties of the sintered body can be ensured.

Furthermore, in the laminated glass ceramic dielectric material of the present invention, the inner layer contains a material whose thermal expansion coefficient after sintering becomes higher than the thermal expansion coefficient of the outer layer after sintering. As a result, the thermal contraction of the inner layer during sintering can be greater than the thermal contraction of the outer layer. As a result, compressive stress is easily generated near the surface of the front and back sides of the sintered body, which can improve the mechanical strength of the sintered body. Furthermore, the above-mentioned compressive stress value is 50 to 100 MPa.

In the laminated glass-ceramic dielectric material of the present invention, it is preferred that the inner layer comprises a material whose thermal expansion coefficient after sintering is higher than the thermal expansion coefficient of the outer layer after sintering by at least 1.5 ppm/K.

Furthermore, in the multilayer glass-ceramic dielectric material of the present invention, it is preferred that the inner layer contains at least crystalline glass powder.

On the other hand, in the laminated glass-ceramic dielectric material of the present invention, it is preferred that the outer layer contains at least amorphous glass powder.

Here, "crystalline glass powder" refers to glass powder that crystallizes when fired at 900°C, and "amorphous glass powder" refers to glass powder that does not crystallize when fired at 900°C. In the laminated glass ceramic dielectric material of the present invention, the inner layer contains at least crystalline glass powder and the outer layer contains at least amorphous glass powder, thereby improving the mechanical strength and making it easy to fire at a temperature below 1000°C, so that metal materials with low melting points such as Ag and Cu can be used as inner conductors.

The laminated glass-ceramic dielectric material of the present invention is preferably used in the form of a laminated green sheet.

Furthermore, the sintered body of the present invention is preferably a sintered body obtained by sintering the above-mentioned multilayer glass ceramic dielectric material, and crystals selected from one or more of calcite, Sr feldspar, barium feldspar, diopside and silica-zinc ore are precipitated from the glass matrix of the inner layer. As described above, by regulating the crystal seeds precipitated from the crystalline glass contained in the inner layer, the mechanical strength of the sintered body can be improved.

In the sintered body of the present invention, the relative dielectric constant of the outer layer when measured at a temperature of 25° C. and a frequency of 28 GHz is preferably 4 or less. As described above, by lowering the relative dielectric constant of the outer layer, signal processing can be performed in the outer layer.

Furthermore, in the sintered body of the present invention, it is preferred that the outer layer substantially does not contain ceramic powder (the content of ceramic powder in the outer layer is less than 0.5 mass %).

The sintered body of the present invention is preferably a sintered body which is layered and integrated in the order of at least an outer layer, an inner layer, and an outer layer, and the relative dielectric constant of the outer layer is less than 5.5 when measured at a temperature of 25°C and a frequency of 28 GHz, and the thermal expansion coefficient of the inner layer is higher than the thermal expansion coefficient of the outer layer.

In the method for manufacturing a sintered body of the present invention, it is preferred to sinter the above-mentioned laminated glass-ceramic dielectric material.

In the method for manufacturing a sintered body of the present invention, it is preferred that the laminated glass-ceramic dielectric material is sintered at a temperature below 1000°C.

The high-frequency circuit component of the present invention is preferably a high-frequency circuit component having a dielectric layer, and the dielectric layer is the above-mentioned sintered body. [Effect of the invention]

The multilayer glass ceramic dielectric material of the present invention has a lower dielectric property in the high frequency region above 20 GHz, and the mechanical strength of the sintered body is higher. Therefore, the multilayer glass ceramic dielectric material of the present invention is suitable as a high frequency circuit component for 5G communication, etc.

The numerical range indicated by "～" in this specification means a range including the numerical values recorded before and after "～" as the minimum and maximum values, respectively. The laminated glass ceramic dielectric material of the present invention is a laminated body laminated in the order of outer layer, inner layer, and outer layer, and in particular, the laminated body in which the inner layer contains crystalline glass powder and the outer layer contains amorphous glass powder is preferred.

First, the inner layer is described.

The glass powder constituting the inner layer is preferably a crystalline glass powder that exhibits a higher thermal expansion coefficient than the outer layer after firing. For example, it is preferred to use a crystalline glass powder having the following properties: when fired, one or more crystals selected from calcite, Sr feldspar, barium feldspar, diopside and silica-zinc ore will precipitate. The thermal expansion coefficient of the glass-ceramic that precipitates the above crystals tends to be higher, and the mechanical strength is higher, so it is easy to improve the mechanical strength of the sintered body. Furthermore, the thermal expansion coefficient of the inner layer glass-ceramic after firing is, for example, approximately 6 to 11 ppm/K at 30 to 380°C.

In order to further improve the mechanical strength of the sintered body, it is preferred to include high-strength ceramic powders such as alumina or zirconia in the crystalline glass powder. When mixing the high-strength ceramic powder, it is preferred that the content of the crystalline glass powder is 50-80% by mass, and the content of the high-strength ceramic powder is 20-50% by mass, and further preferably the content of the crystalline glass powder is 60-75% by mass, and the content of the high-strength ceramic powder is 25-40% by mass. When the content of the high-strength ceramic powder is too high, the densification of the sintered body becomes difficult. On the other hand, when the high-strength ceramic powder is too low, the mechanical strength of the sintered body is easily reduced.

As high-strength ceramic powder, in addition to aluminum oxide and zirconium oxide, other ceramic powders may also be introduced. For example, other ceramic powders may be one or more selected from silicon carbide, silicon nitride, and aluminum nitride.

The crystallization temperature _T1 of the inner layer is preferably 850-900°C, especially 870-900°C. When _T1 is too low, the substrate will be easily warped. On the other hand, when _T1 is too high, the sintering temperature will become high.

The composition of the crystalline glass powder can be selected according to the crystal seeds to be precipitated. The crystalline glass powder for precipitating calcium feldspar preferably contains 40-60% SiO ₂ , 1-20% Al ₂ O ₃ , 15-30% CaO and 0-10% B ₂ O ₃ as the glass composition by mass %. The crystalline glass powder for precipitating Sr-based feldspar preferably contains 20-40% SiO ₂ , 20-40% Al ₂ O ₃ , 10-30% SrO, 10-20% MgO and 0-10% B ₂ O ₃ as the glass composition by mass %. The crystalline glass powder of precipitated barium feldspar preferably contains, by mass%, 35-60% SiO ₂ , 1-10% Al ₂ O ₃ , 20-40% BaO and 10-20% MgO as glass compositions. The crystalline glass powder of precipitated diopside preferably contains, by mass%, 40-60% SiO ₂ , 0-10% Al ₂ O ₃ , 10-25% MgO and 15-35% CaO as glass compositions. The crystalline glass powder of precipitated silicon zinc ore preferably contains, by mass%, 30-60% SiO ₂ , 10-30% CaO, 10-20% MgO and 10-30% ZnO as glass compositions.

The relative dielectric constant of the inner layer after sintering at 25°C and 28 GHz is preferably less than 10, especially less than 9.5. When the relative dielectric constant is too high, the signal processing speed tends to be slow. In addition, there is no particular lower limit for the relative dielectric constant, and it is actually greater than 5.

In addition, the dielectric loss tangent of the inner layer is preferably less than 0.0040, especially less than 0.0038 at 25°C and 28 GHz after sintering. When the dielectric loss tangent is too high, the loss of the transmission signal tends to increase. Furthermore, the lower limit of the dielectric loss tangent is not particularly limited, and is actually greater than 0.0005.

Next, the outer layer is described.

The amorphous glass powder contained in the outer layer preferably exhibits a lower thermal expansion coefficient than the inner layer after firing, and the relative dielectric constant at 25°C and 28 GHz is 5.5 or less, especially 4 or less. In addition, the dielectric loss tangent is preferably 0.0020 or less. Furthermore, the thermal expansion coefficient of the outer layer after firing is amorphous glass ceramic, for example, about 5.5 to 6.5 ppm/K at 30 to 380°C, and in the case of amorphous glass, for example, about 3.5 to 4.5 ppm/K.

The amorphous glass powder is preferably a borosilicate glass with low expansion and low relative dielectric constant, and preferably contains 70-80% _SiO2 , 15-30% _B2O3 and 0.1-5% _Li2O + _Na2O + _K2O (the total amount of _Li2O , _Na2O and _K2O ) as a glass composition by mass%. In _addition , the content of _Li2O , _Na2O and _K2O is preferably 0-3% respectively.

In order to further reduce the relative dielectric constant, a low dielectric constant ceramic powder having a relative dielectric constant of 5.5 or less, especially 4 or less, may be included in the amorphous glass powder. In the case where the relative dielectric constant of the amorphous glass powder is low enough, the low dielectric constant ceramic powder may not be included. When the low dielectric constant ceramic powder is included, it is preferred that the content of the amorphous glass powder is 60-80% by mass and the content of the low dielectric constant ceramic powder is 20-40% by mass. When the content of the low dielectric constant ceramic powder is too high, densification of the sintered body becomes difficult. On the other hand, when the low dielectric constant ceramic powder is too little, the relative dielectric constant is difficult to reduce.

The low dielectric constant ceramic powder is preferably α-quartz, α-knosslite or β-phospho-quartz having a relative dielectric constant of 5 or less and a dielectric loss tangent of 0.0010 or less in a high frequency region above 20 GHz.

The softening point _T2 of the outer layer is preferably 770-840°C, especially 790-830°C. When _T2 is too low, the heat resistance will decrease. On the other hand, when _T2 is too high, the sintering temperature will become high.

The outer layer preferably has a relative dielectric constant of 5.5 or less, especially 4 or less, at 25°C and 28 GHz after sintering. When the relative dielectric constant is too high, the signal processing speed tends to be slow. In addition, there is no particular lower limit for the relative dielectric constant, and it is actually above 2.5.

In addition, the outer layer preferably has a dielectric loss tangent of 0.0025 or less, and particularly 0.0020 or less, at 25°C and 28 GHz after sintering. When the dielectric loss tangent is too high, the loss of the transmission signal tends to increase. Furthermore, the lower limit of the dielectric loss tangent is not particularly limited, and is actually 0.0005 or more.

Next, the method for manufacturing the sintered body of the present invention is described below.

First, a specific amount of binder, plasticizer and solvent are added to the glass powder or the mixed powder of glass powder and ceramic powder to prepare a slurry. The binder is preferably polyvinyl butyral resin, methacrylate resin, etc., the plasticizer is preferably dibutyl phthalate, etc., and the solvent is preferably toluene, methyl ethyl ketone, etc.

Next, after the slurry is formed into a blank by a scraper method, it is dried, cut into specific sizes, and then mechanically processed to form via holes, and a silver conductor or a low-resistance metal material to be an electrode is printed on the via holes and the surface of the blank. Next, a sheet containing crystalline glass powder is arranged on the inner layer, and a sheet containing amorphous glass powder is arranged on the outer layer, and laminated and integrated by hot pressing to obtain a laminated blank. Furthermore, the thickness of the laminated blank is preferably such that the inner layer accounts for more than 1/3 of the total, especially more than half. Specifically, the inner layer is preferably 0.2 to 3 mm after lamination, and the outer layer is preferably 0.1 to 1.5 mm, respectively. When the inner layer is too thin, it is difficult to achieve the effect of increasing strength due to the difference in thermal expansion coefficients between the inner layer and the outer layer.

The temperature difference T 1 -T ₂ between the crystallization temperature T ₁ of the inner layer and the softening point T 2 of the outer layer is preferably 50-120°C, especially 60-110° _{C. When T 1 -T 2 is too small, the substrate will be easily warped. On the other hand, when T 1 -T 2 is too large , there} is a risk of increased diffusion of the conductor.

Furthermore, when the laminated green sheets are fired, a sintered body can be obtained. The sintered body thus produced has a conductor or an electrode inside or on the surface. Furthermore, from the perspective of using a low melting point metal material such as Ag and Cu with low conductor loss, the firing temperature is preferably below 1000°C, especially 800 to 950°C.

Furthermore, a constraining layer such as aluminum oxide that does not shrink below 1000°C can be placed on the outer surfaces of the press-bonded body before firing, so that the layer does not shrink in the XY direction. By performing constrained firing, warping, cracking, and interlayer peeling can be prevented.

The produced sintered body preferably has a higher thermal expansion coefficient of the inner layer than that of the outer layer. Specifically, the difference between the thermal expansion coefficient of the inner layer and the thermal expansion coefficient of the outer layer is preferably 1.5 ppm/K or more, 1.6 ppm/K or more, and especially 1.7 ppm/K or more, and preferably 10 ppm/K or less, 6 ppm/K or less, and especially 5.3 ppm/K or less. The greater the difference in thermal expansion coefficient, the easier it is to generate compressive stress near the surface of the front and back of the sintered body, which can improve the mechanical strength of the sintered body. On the other hand, when the difference in thermal expansion coefficient is too large, peeling will easily occur at the interface between the inner layer and the outer layer.

The three-point bending strength of the produced sintered body is preferably 300 MPa or more, and particularly 310 MPa or more. The higher the three-point bending strength, the less likely the sintered body will crack.

The high-frequency circuit component of the present invention is preferably a high-frequency circuit component having a dielectric layer, and the dielectric layer is the above-mentioned sintered body. The high-frequency circuit component of the present invention can be manufactured by forming a coil using wiring, or by connecting a chip of a Si-based or GaAs-based semiconductor element to the surface of the sintered body manufactured as described above. [Example]

Hereinafter, the present invention will be described based on the embodiments. However, the present invention is not limited to the following embodiments, which are merely illustrative.

Table 1 shows the examples (samples No. 1 to 7) and the comparative example (sample No. 8) of the present invention. In Table 1, R ₂ O means Li ₂ O + Na ₂ O + K ₂ O. CTE in Table 1 means coefficient of thermal expansion.

[Table 1] No.1 No.2 No.3 No.4 No.5 No.6 No.7 No.8 Inner glass composition (wt%) SiO ₂ 55 30 44 53 45 54 50 10 Al ₂ O ₃ 14 28 4 5 15 6 _{B2O3 ​} 6 5 8 10 30 MgO 1 15 15 17 15 3 CaO twenty four 10 25 twenty one 20 12 SrO 20 BaO 27 20 ZnO 2 19 2 60 Inner layer ceramic powder (wt%) Zirconia (30) Zirconia (30) Alumina(40) Alumina(30) Alumina(38) Alumina(35) Alumina(40) Alumina(20) Inner layer crystallization temperature T ₁ (℃) 890 895 900 895 890 900 --- 790 Crystallization Calcium feldspar Sr feldspar Barium feldspar Translucent Translucent silica zinc ore Calcium feldspar --- Zinc borate Inner layer relative dielectric constant 8.5 9.5 8.0 7.5 8.2 7.5 7.2 9.0 Inner layer dielectric loss tangent 0.0022 0.0012 0.0009 0.0007 0.0015 0.0024 0.0035 0.0050 Inner layer CTE (ppm/K) 7.6 7.8 7.9 8.2 7.4 7.9 6.8 3.1 Outer glass composition (wt%) SiO ₂ 79 79 79 78 78 78 79 78 _{B2O3 ​} 19 19 19 twenty one twenty one twenty one 19 twenty one _R2O 2 2 2 1 1 1 2 1 _Li2O 0.9 0.8 0.7 0.4 0.3 0.3 0.8 0.4 _Na2O 0.9 0.8 0.9 0.5 0.5 0.6 0.9 0.5 _K2O 0.2 0.4 0.4 0.1 0.2 0.1 0.3 0.1 Outer layer ceramic powder (wt%) -- -- -- Alpha Quartz(25) Alpha Quartz(25) Alpha Quartz(25) -- Alpha Quartz(25) Outer layer softening point T ₂ (℃) 810 810 810 820 820 820 810 820 Relative dielectric constant of outer layer 4.0 4.0 4.0 3.8 3.8 3.8 4.0 3.8 Outer layer dielectric loss tangent 0.0018 0.0018 0.0018 0.0015 0.0015 0.0014 0.0018 0.0015 Outer layer CTE (ppm/K) 2.6 2.6 2.6 5.6 5.6 5.6 2.6 5.6 Inner layer CTE - Outer layer CTE (ppm/K) 5.0 5.2 5.3 2.6 1.8 2.3 4.2 -2.5 Three-point bending strength (MPa) 350 330 380 380 300 320 200 100 T ₁ －T ₂ (℃) 80 85 90 75 70 80 -- -30

Each sample was prepared as follows. First, glass raw materials of various oxides were prepared in such a manner as to obtain the glass composition shown in Table 1, and after being uniformly mixed, they were placed in a platinum crucible and melted at 1400-1600°C for 3-8 hours, and the molten glass was formed into a thin plate by a water-cooled roller. Then, the obtained glass film was coarsely crushed, alcohol was added, and wet-crushed by a ball mill, and classified so that the average particle size became 1.5-3 μm to obtain glass powder.

Next, the glass powder was uniformly mixed with the ceramic powder (average particle size 2 μm) in the amount shown in Table 1 to obtain a glass ceramic dielectric material.

Next, 15% by mass of polyvinyl butyral as a binder, 4% by mass of benzyl butyl phthalate as a plasticizer, and 30% by mass of toluene as a solvent were added to the obtained glass ceramic dielectric material to prepare a slurry. Next, the slurry was formed into a 150 μm green sheet by a doctor blade method, dried, cut into a specific size, and then the inner layer was laminated into 4 layers and the outer layer was laminated into 2 layers each, and integrated by hot pressing. Furthermore, the obtained laminated green sheet was sintered at 900°C for 1 hour to obtain a sintered body.

The crystal phase of each sample obtained in this way was identified, and the relative dielectric constant, dielectric loss tangent, difference in thermal expansion coefficient between the inner layer and the outer layer, three-point bending strength of the sintered body, and difference between the crystallization temperature _T1 of the inner layer and the softening point _T2 of the outer layer were evaluated. The results are shown in Table 1.

The crystalline phase was identified by powder X-ray diffraction.

The relative dielectric constant and dielectric loss tangent were obtained by sintering the green sheets at 900°C and processing them into a size of 25 mm × 50 mm × 0.1 mm to make test specimens. The specimens were then measured at a temperature of 25°C and a frequency of 28 GHz based on the method for determining the microwave dielectric properties of precision ceramic substrates (JIS R1641).

The difference in thermal expansion coefficient between the inner layer and the outer layer (inner layer CTE - outer layer CTE) was calculated by measuring the inner layer and the outer layer sintered at 900°C in the temperature range of 30 to 380°C using a thermomechanical analysis device.

The three-point bending strength is evaluated according to JIS R1601.

The crystallization temperature _T1 of the inner layer and the softening point _T2 of the outer layer were measured using a large differential thermal analyzer. Specifically, the inner layer and the outer layer before sintering were measured using a large differential thermal analyzer at a heating rate of 10°C/min to 1050°C. The value of the fourth inflection point in the measured graph was set as the softening point, and the stronger exothermic peak was set as the crystallization temperature. In addition, the difference between the above crystallization temperature and the softening point was calculated in the form of _T1 - _T2 .

According to the table, the difference in thermal expansion coefficient between the inner layer and the outer layer of samples No. 1 to 7 (inner layer CTE - outer layer CTE) is 1.8 to 5.3 ppm/K, so the three-point bending strength is higher, 200 to 380 MPa. In addition, the relative dielectric constant of the outer layer is lower, 3.8 to 4.0, so the attenuation of the signal at frequencies above 20 GHz is reduced.

On the other hand, the difference in thermal expansion coefficient between the inner layer and the outer layer of sample No. 8 (inner layer CTE - outer layer CTE) is -2.5 ppm/K, so the three-point bending strength is lower, which is 100 MPa.

Claims (11)

A laminated glass ceramic dielectric material, characterized in that it has a laminated structure in which at least an outer layer, an inner layer, and an outer layer are laminated in the order of outer layer, the outer layer comprises a material having a relative dielectric constant of 5.5 or less when the measured temperature after sintering is 25°C and the frequency is 28 GHz, and the inner layer comprises a material having a thermal expansion coefficient after sintering higher than the thermal expansion coefficient of the outer layer after sintering, and contains a crystalline glass powder selected from one or more of Sr feldspar and silicon zinc ore precipitated from the glass matrix of the inner layer. For example, the laminated glass ceramic dielectric material of claim 1, wherein the inner layer comprises a material having a thermal expansion coefficient after sintering that is 1.5 ppm/K higher than the thermal expansion coefficient of the outer layer after sintering, and the thermal expansion coefficient is an average value measured within a temperature range of 30 to 380°C. The laminated glass ceramic dielectric material of claim 1 or 2, wherein the outer layer contains at least amorphous glass powder. The laminated glass ceramic dielectric material of claim 1 or 2 is provided in the form of a laminated green sheet. A sintered body characterized in that it is a sintered body obtained by sintering a multilayer glass ceramic dielectric material as described in any one of claims 1 to 4, and crystals selected from one or more of Sr feldspar and silicon-zinc ore are precipitated from the glass matrix of the inner layer. For example, in the sintered body of claim 5, the relative dielectric constant of the outer layer is less than 4 when the temperature is measured at 25°C and the frequency is 28 GHz. For example, a sintered body as claimed in claim 5 or 6, wherein the outer layer does not substantially contain ceramic powder. A sintered body characterized in that it is a sintered body that is integrated by laminating at least in the order of outer layer, inner layer, and outer layer, and the relative dielectric constant of the outer layer is less than 5.5 when the temperature is 25°C and the frequency is 28GHz, and the inner layer contains crystalline glass powder selected from one or more of Sr feldspar and silicon zinc ore precipitated from the glass matrix of the inner layer, and the thermal expansion coefficient of the inner layer is higher than the thermal expansion coefficient of the outer layer. A method for manufacturing a sintered body, characterized in that a layered glass ceramic dielectric material as described in any one of claims 1 to 4 is sintered. A method for manufacturing a sintered body as claimed in claim 9, wherein the sintering is performed at a temperature below 1000°C. A high-frequency circuit component, characterized in that it is a high-frequency circuit component having a dielectric layer, and the dielectric layer is a sintered body as described in any one of claims 5 to 8.