Glass ceramics and electronic components

Abstract

A glass ceramic including an aggregate and glass that includes Si, B, Al, and Zn, wherein the glass ceramic includes 45-80 wt% inclusive of the glass and, relative to the weight of the glass ceramic, 20-50 wt% inclusive of SiO2, 20 wt% or less of Al2O3, and 10 wt% or less of ZnO as the aggregate.

Description

[Technical Field]

[0001] The present invention relates to glass ceramics and electronic components. [Background technology]

[0002] Glass ceramic materials that can be fired at low temperatures are known as ceramic materials for use in ceramic multilayer wiring substrates.

[0003] For example, Patent Document 1 discloses a glass composition for low-temperature firing substrates, which has a basic composition of RO-Al2O3-B2O3-SiO2 (where RO is one or more of the group consisting of MgO, CaO, SrO, BaO, and ZnO), in which RO and Al2O3 are both within the range of 1 to 25 mol%, and the SiO2 / B2O3 mol% ratio is 1.3 or less, and a glass ceramics in which the glass composition for low-temperature firing substrates contains an aggregate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-26529 Summary of the Invention [Problem to be solved by the invention]

[0005] The glass ceramics described in Patent Document 1 has a thermal conductivity of 20×10 at 3 GHz. -4 It is possible to achieve excellent dielectric loss of less than 1000kJ / s.

[0006] However, the glass composition for low-temperature fired substrates described in Patent Document 1 has a SiO2 / B2O3 mol% ratio of 1.3 or less and a high B (boron) content. While such high-boron glass can reduce dielectric loss, it has the problem of an unstable boron content. Specifically, problems arise such as boron elution into the solvent during mixing and grinding, and boron volatilization during firing. If the boron content decreases due to elution or volatilization, the viscosity of the glass decreases during firing, causing insufficient sintering. Furthermore, glass with reduced boron content due to elution or volatilization is chemically unstable and has poor moisture resistance and plating solution resistance, which may lead to a deterioration in quality.

[0007] Furthermore, the glass ceramics described in Patent Document 1 has a low thermal expansion coefficient of less than 6 ppm / K, which is significantly different from the thermal expansion coefficients of other dielectrics and mounting substrates, and is therefore likely to cause quality defects.

[0008] The present invention has been made to solve the above problems, and has an object to provide a glass ceramic having a small relative permittivity and dielectric loss, and a large thermal expansion coefficient. [Means for solving the problem]

[0009] One embodiment of the glass ceramic of the present invention is a glass ceramic including a glass containing Si, B, Al, and Zn, and an aggregate, wherein the glass is contained in an amount of 45 wt % or more and 80 wt % or less, and the aggregate includes, relative to the weight of the glass ceramic, 20 wt % or more and 50 wt % or less of SiO2, 20 wt % or less of Al2O3, and 10 wt % or less of ZnO.

[0010] Another embodiment of the glass-ceramic of the present invention is a glass-ceramic comprising Si, B, Al, and Zn, wherein the SiO content is 52.00 to 71.58 wt. %; the BO content is 6.30 to 21.00 wt. %; the AlO content is 7.63 to 22.00 wt. %; the ZnO content is 5.04 to 17.00 wt. %; and the LiO content is 0.55 wt. %.

[0011] The electronic component of the present invention includes a glass ceramic layer that is a sintered body of the glass ceramic of the present invention. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a glass ceramic having a small relative permittivity and dielectric loss, and a large thermal expansion coefficient. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view schematically showing an example of a multilayer ceramic electronic component as an electronic component of the present invention. [Figure 2] FIG. 2 is a cross-sectional view showing a laminated green sheet (unfired state) produced in the manufacturing process of the laminated ceramic electronic component shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0014] The glass ceramics and electronic components of the present invention will be described below. Note that the present invention is not limited to the following configurations and may be modified as appropriate within the scope of the present invention. In addition, a combination of multiple individual preferred configurations described below also constitutes the present invention.

[0015] The glass-ceramic of the present invention is a low-temperature co-fired ceramic (LTCC) material. In this specification, the term "low-temperature co-fired ceramic material" refers to a glass-ceramic material that can be sintered at a firing temperature of 1000°C or less.

[0016] One embodiment of the glass ceramic of the present invention is a glass ceramic including a glass containing Si, B, Al, and Zn, and an aggregate, wherein the glass content is 45 wt % or more and 80 wt % or less, and the aggregate includes 20 wt % or more and 50 wt % or less of SiO2, 20 wt % or less of Al2O3, and 10 wt % or less of ZnO, relative to the weight of the glass ceramic.

[0017] The glass used in the present invention contains Si, B, Al and Zn. The glass preferably has an SiO2 content of 15% by weight or more and 65% by weight or less, a B2O3 content of 11% by weight or more and 30% by weight or less, a weight ratio of SiO2 to B2O3 (SiO2 / B2O3) of 1.21 or more, and a weight ratio of Al2O3 to ZnO (Al2O3 / ZnO) of 0.75 or more and 1.64 or less.

[0018] The SiO2 content in the glass is preferably 15% by weight or more and 65% by weight or less, and more preferably 45% by weight or more and 60% by weight or less. When the SiO2 content is 15% by weight or more and 65% by weight or less, the relative dielectric constant of the glass-ceramic containing the glass is reduced when sintered. As a result, stray capacitance and other issues associated with higher frequencies of electrical signals are suppressed.

[0019] If the SiO2 content in the glass exceeds 65% by weight, problems arise, such as difficulty in sintering below 1000°C, or an increase in the crystallization temperature, making it difficult for ZnAl2O4 crystals to precipitate. In particular, if the crystallization temperature exceeds 1000°C, crystals do not precipitate during firing of the glass-ceramics, and the Q value of the glass-ceramics tends to decrease. On the other hand, if the SiO2 content in the glass is less than 15% by weight, the viscosity decreases too much, making vitrification difficult.

[0020] The B2O3 in the glass contributes to a decrease in the glass viscosity, which results in a dense sintered glass-ceramic body. The content of B2O3 in the glass is preferably 11% by weight or more and 30% by weight or less, and more preferably 15% by weight or more and 30% by weight or less. Furthermore, the weight ratio of SiO to B O is preferably 1.21 or more. When the weight ratio is within this range, the proportion of B O in the entire glass is small. Therefore, boron is less likely to be eluted or volatilized from the glass, and problems such as insufficient sintering and reduced resistance to plating solutions are less likely to occur. In addition, the weight ratio of SiO2 to B2O3 (SiO2 / B2O3) is preferably 4 or less.

[0021] Al2O3 in the glass contributes to improving the chemical stability of the glass, and ZnO in the glass forms a crystalline phase of ZnAl2O4 together with Al2O3. When glass contains Al and Zn, ZnAl2O4 crystals are precipitated in the glass, which contributes to reducing loss. The weight ratio of Al2O3 to ZnO (Al2O3 / ZnO) is preferably 0.75 to 1.64. When the weight ratio falls within this range, the content of ZnAl2O4 in the glass falls within a preferred range. If the weight ratio of Al2O3 to ZnO (Al2O3 / ZnO) is less than 0.75, the amount of ZnO becomes too high, resulting in a decrease in the Q value, which is the reciprocal of the dielectric loss. On the other hand, if the weight ratio of Al2O3 to ZnO (Al2O3 / ZnO) exceeds 1.64, the amount of Al2O3 becomes too high, increasing the viscosity of the glass and making it impossible to obtain a dense sintered body.

[0022] In the glass ceramics of the present invention, the glass is preferably glass-ceramic, and contains ZnAl2O4, which is a crystalline phase precipitated from the glass. Precipitation of ZnAl2O4 during firing of glass ceramics results in glass ceramics with low dielectric loss and a high Q value. For this reason, it is preferable that the crystallization temperature of the glass is equal to or lower than the temperature at which the glass ceramics is fired. Specifically, it is preferable that the crystallization temperature of the glass is 1000°C or lower. If the crystallization temperature of the glass is 1000°C or lower, the Q value can be increased.

[0023] In the glass ceramic of the present invention, the glass may contain Li2O as a minor component. The Li2O content is preferably 1.0 wt% or less. Li2O in the glass contributes to a decrease in the viscosity of the glass. When Li2O is contained in the glass, the sinterability of the glass ceramic is improved.

[0024] The glass ceramic of the present invention contains 20% by weight or more and 50% by weight or less of SiO2 as an aggregate. Quartz is the preferred SiO2 aggregate. Because quartz has a low dielectric constant, its use as an aggregate can lower the dielectric constant of glass ceramics. Quartz also contributes to a higher thermal expansion coefficient when glass ceramics are sintered. While the thermal expansion coefficient of glass is approximately 6 ppm / K, that of quartz is approximately 15 ppm / K. Therefore, glass ceramics containing quartz achieve a high thermal expansion coefficient when sintered. This reduces the difference in thermal expansion between the glass ceramics and the metal materials used as electrodes, such as Ag and Cu, which reduces the thermal stress generated during the cooling process after sintering, making it less likely to develop internal defects such as cracks around the electrodes. It also improves reliability when mounted on a mounting substrate (e.g., a resin substrate). However, the Q value tends to decrease slightly as the amount of quartz added increases.

[0025] When the content of SiO2 as aggregate is 20% by weight or more and 50% by weight or less, the thermal expansion coefficient of the glass ceramic can be increased to approach that of the conductive layer made of copper, silver, etc. When the content of SiO2 as aggregate is less than 20% by weight, the thermal expansion coefficient of the glass ceramic may be too small. When the content of SiO2 as aggregate is more than 50% by weight, the thermal expansion coefficient of the glass ceramic may be large.

[0026] Amorphous silica or silica glass may be used as the SiO2 aggregate. Amorphous silica and silica glass have even lower dielectric constants than quartz, so the dielectric constant of the glass ceramic can be further reduced. A combination of quartz, amorphous silica, and silica glass may also be used.

[0027] The glass ceramic of the present invention contains 20% by weight or less of Al2O3 as an aggregate. The glass ceramic of the present invention does not necessarily need to contain Al2O3 as a filler. The addition of Al2O3 as an aggregate contributes to low dielectric loss and high mechanical strength when the glass ceramics are sintered. Specifically, the addition of Al2O3 increases the Q value. The flexural strength also increases, and the use of Al2O3 as an aggregate makes it possible to obtain glass ceramics with a flexural strength exceeding 150 MPa. The flexural strength of glass ceramics affects the strength of electronic components, so a higher flexural strength is preferable. A value of 150 MPa or higher is particularly preferable. The improvement in bending strength is thought to be due to the fact that the addition of Al2O3 as an aggregate promotes the precipitation of ZnAl2O4 from the glass, and also due to the inclusion of Al2O3 as a crystalline phase with a high Q value and high strength.

[0028] Furthermore, the inclusion of Al2O3 as an aggregate can prevent the precipitation of cristobalite crystals when the glass ceramics is sintered. Cristobalite crystals are a type of SiO2 crystal, and undergo a phase transition at approximately 280°C. Therefore, if cristobalite crystals precipitate during the sintering process of the glass ceramics, their volume will change significantly in a high-temperature environment, reducing reliability. From this perspective, it is preferable that the glass ceramics do not contain cristobalite crystals. Here, "not containing cristobalite crystals" means that the content of cristobalite crystals is below the detection limit. The presence or absence of cristobalite crystal precipitation can be confirmed by crystal structure analysis such as X-ray diffraction (XRD).

[0029] To achieve the above-mentioned effects of including Al2O3 as an aggregate, the amount of Al2O3 added is preferably 1 wt% or more. However, the addition of Al2O3 increases the relative dielectric constant of the glass ceramics. Therefore, the amount of Al2O3 added as an aggregate is preferably 10 wt% or less. Furthermore, if the amount of Al2O3 added as an aggregate exceeds 20 wt%, the sintering of the glass ceramics is hindered.

[0030] The glass ceramic of the present invention contains 10% by weight or less of ZnO as a filler. The glass ceramic of the present invention does not necessarily need to contain ZnO as a filler. The inclusion of ZnO as an aggregate can improve sinterability and also compensate for the volatile component of ZnO in the glass.

[0031] To achieve the above-mentioned effects of including ZnO as an aggregate, the amount of ZnO added is preferably 1.0 wt% or more, and more preferably 2.5 wt% or more. However, if the amount of ZnO added as an aggregate exceeds 10 wt%, the relative dielectric constant of the glass ceramics increases. Furthermore, the addition of ZnO may result in the formation of Zn2SiO4 (willemite) during firing.

[0032] The glass ceramic of the present invention preferably contains SiO2, ZnAl2O4, and Al2O3 as crystalline phases. When the fired glass ceramic contains SiO2, ZnAl2O4, and Al2O3 as crystalline phases, it becomes a glass ceramic with a low relative permittivity, low dielectric loss, a high Q value, a large thermal expansion coefficient, and high flexural strength. The SiO2 crystalline phase is preferably quartz, and the ZnAl2O4 crystalline phase is preferably gahnite. The presence of these crystalline phases can be confirmed by crystal structure analysis such as X-ray diffraction (XRD).

[0033] The glass ceramic of the present invention preferably has a relative dielectric constant of 5.0 or less, more preferably 4.5 or less, and even more preferably 4.3 or less. The relative dielectric constant of glass ceramics is determined as measured at 6 GHz or 30 GHz. The relative permittivity at 6 GHz can be measured by the perturbation method. The relative permittivity at 30GHz is TE according to JIS R 1641 011 It can be measured by the modal cavity resonator method.

[0034] The present invention provides glass-ceramics with a low boron content, small relative permittivity and dielectric loss, a high Q value, and a large thermal expansion coefficient. Furthermore, by including Al2O3 as an aggregate, the Q value can be increased and the flexural strength can be improved.

[0035] In the glass ceramics of the present invention, the glass and the aggregate can be distinguished or separated by analyzing the electron diffraction pattern using a scanning electron microscope (SEM) or a transmission electron microscope (TEM), or by dissolving the glass portion with hydrogen fluoride or the like. The compositions of the glass and aggregate can be measured by performing elemental analysis such as wavelength dispersive X-ray analysis (WDX), energy dispersive X-ray analysis (EDX), and inductively coupled plasma optical emission spectroscopy (ICP) on the distinguished or separated glass and aggregate. The SiO2 content of the glass and the SiO2 content of the aggregate can be measured by the above methods. The same applies to other elements.

[0036] Another embodiment of the glass-ceramic of the present invention is a glass-ceramic comprising Si, B, Al, and Zn, wherein the SiO content is 52.00 to 71.58 wt. %; the BO content is 6.30 to 21.00 wt. %; the AlO content is 7.63 to 22.00 wt. %; the ZnO content is 5.04 to 17.00 wt. %; and the LiO content is 0.55 wt. %. In addition, the SiO2 content is preferably 60% by weight or more, the B2O3 content is preferably 15% by weight or less, the Al2O3 content is preferably 15% by weight or less, and the ZnO content is preferably 12% by weight or less.

[0037] The other embodiment of the glass ceramic of the present invention corresponds to a part of the embodiment of the glass ceramic in which the contents of Si, B, Al, and Zn are specified without distinguishing between glass and aggregate, and therefore the other embodiment of the glass ceramic of the present invention exhibits the same effects as the embodiment of the glass ceramic of the present invention.

[0038] [Electronic Components] The electronic component of the present invention includes a glass ceramic layer that is a sintered body of the glass ceramic of the present invention.

[0039] Examples of the electronic component of the present invention include a laminate including a plurality of glass ceramic layers that are sintered bodies of the glass ceramic of the present invention, and a multilayer ceramic electronic component including a multilayer ceramic substrate using the laminate and a chip component mounted on the ceramic substrate. The electronic component of the present invention has a low dielectric constant and low dielectric loss because it includes a glass ceramic layer that is a sintered body of the glass ceramic of the present invention.

[0040] A laminate comprising a plurality of glass ceramic layers, which are sintered bodies of the glass ceramic of the present invention, can be used, for example, in ceramic multilayer substrates for communication and laminated dielectric filters. The electronic component of the present invention has a small relative permittivity and dielectric loss and a high Q value, and is therefore particularly suitable as an electronic component for use in the millimeter wave band.

[0041] The thermal expansion coefficient of the glass ceramic layer is preferably 6 ppm / K or more. The glass ceramic layer preferably has a relative dielectric constant of 4.5 or less. The Q value of the glass ceramic layer is preferably 800 or more. The glass ceramic layer preferably has a bending strength of 150 MPa or more.

[0042] The electronic component of the present invention includes an electrode made of a metal containing Cu, and the amount of Cu contained in the glass ceramic layer is preferably 0.5% by weight or less in terms of CuO. When Cu is used as an electrode, Cu diffuses from the electrode into the glass ceramic. This diffusion can change the sinterability of the glass ceramic around the electrode, resulting in defects such as voids. Adding a small amount of CuO as an aggregate to the glass ceramic can prevent these defects. While it is possible to add more than 0.5 wt% Cu (calculated as CuO), this increases the likelihood of Cu precipitation within the glass ceramic, raising concerns about short circuits between electrodes when used in electronic components.

[0043] Fig. 1 is a cross-sectional view schematically showing an example of a multilayer ceramic electronic component as an electronic component of the present invention. As shown in Fig. 1, the electronic component 2 includes a laminate 1 formed by laminating a plurality of glass ceramic layers 3 (five layers in Fig. 1), and chip components 13 and 14 mounted on the laminate 1. The laminate 1 also serves as a multilayer ceramic substrate.

[0044] The glass ceramic layer 3 is a sintered body of the glass ceramic of the present invention. Therefore, the laminate 1 formed by laminating a plurality of glass ceramic layers 3, the multilayer ceramic substrate using the laminate 1, and the electronic component 2 including chip components 13, 14 mounted on the multilayer ceramic substrate (laminate 1) are all electronic components of the present invention. The compositions of the plurality of glass ceramic layers 3 may be the same or different from one another, but are preferably the same.

[0045] The laminate 1 may further include a conductor layer. The conductor layer may constitute, for example, a passive element such as a capacitor or an inductor, or may constitute a connecting wiring that electrically connects elements. Such conductor layers include conductor layers 9, 10, and 11, and a via-hole conductor layer 12, as shown in FIG. 1.

[0046] The conductor layers 9, 10, and 11 and the via-hole conductor layer 12 preferably contain Ag or Cu as a main component. The use of such low-resistance metals prevents signal propagation delays that occur with higher frequencies of electrical signals. Furthermore, since the glass ceramic of the present invention is used as the constituent material of the glass ceramic layer 3, it can be co-fired with Ag and Cu.

[0047] The conductor layer 9 is disposed inside the laminate 1. Specifically, the conductor layer 9 is disposed at the interface between the glass ceramic layers 3.

[0048] The conductor layer 10 is disposed on one of the main surfaces of the laminate 1 .

[0049] The conductor layer 11 is disposed on the other main surface of the laminate 1 .

[0050] The via hole conductor layer 12 is arranged to penetrate the glass ceramic layer 3, and serves to electrically connect the conductor layers 9 of different layers, electrically connect the conductor layers 9 and 10, and electrically connect the conductor layers 9 and 11.

[0051] The laminate 1 is produced, for example, as follows.

[0052] (A) Glass preparation The glass is prepared by mixing SiO2, B2O3, Al2O3, ZnO, and any other minor components (such as Li2O) that are added as needed, so that the SiO2 content is 15% by weight or more and 65% by weight or less, the B2O3 content is 11% by weight or more and 30% by weight or less, the weight ratio of SiO2 to B2O3 (SiO2 / B2O3) is 1.21 or more, and the weight ratio of Al2O3 to ZnO (Al2O3 / ZnO) is 0.75 or more and 1.64 or less.

[0053] (B) Preparation of glass ceramics The glass ceramics of the present invention are prepared by mixing glass with SiO2, Al2O3 and ZnO as fillers, and other fillers (such as CuO) that are added as needed.

[0054] (C) Preparation of green sheets The glass ceramic of the present invention is mixed with a binder, a plasticizer, etc. to prepare a ceramic slurry. The ceramic slurry is then cast onto a substrate film (e.g., a polyethylene terephthalate (PET) film) and dried to produce a green sheet.

[0055] (D) Fabrication of laminated green sheets A laminated green sheet (unfired state) is produced by stacking green sheets. FIG. 2 is a cross-sectional schematic diagram showing a laminated green sheet (unfired state) produced in the manufacturing process of the multilayer ceramic electronic component in FIG. 1. As shown in FIG. 2, a laminated green sheet 21 is formed by stacking a plurality of green sheets 22 (five sheets in FIG. 2). The green sheets 22 will become the glass ceramic layer 3 after firing. Conductive layers including conductor layers 9, 10, and 11 and a via-hole conductor layer 12 may be formed on the laminated green sheet 21. The conductor layers can be formed by screen printing, photolithography, or the like using a conductive paste containing Ag or Cu.

[0056] (E) Firing of laminated green sheets The laminated green sheet 21 is fired, resulting in a laminated body 1 as shown in FIG.

[0057] The firing temperature of the laminated green sheet 21 is not particularly limited as long as it is a temperature at which the glass ceramic of the present invention constituting the green sheet 22 can be sintered, and may be, for example, 1000° C. or lower.

[0058] The firing atmosphere for the laminated green sheet 21 is not particularly limited, but an air atmosphere is preferred when a material that is resistant to oxidation, such as Ag, is used for the conductor layers 9, 10, 11 and the via-hole conductor layer 12, and a low-oxygen atmosphere such as a nitrogen atmosphere is preferred when a material that is resistant to oxidation, such as Cu, is used. The firing atmosphere for the laminated green sheet 21 may also be a reducing atmosphere.

[0059] The laminated green sheet 21 may be fired while sandwiched between constraining green sheets. The constraining green sheets contain, as a main component, an inorganic material (e.g., Al2O3) that does not substantially sinter at the sintering temperature of the glass ceramic of the present invention that constitutes the green sheet 22. Therefore, the constraining green sheets do not shrink when the laminated green sheet 21 is fired, and act to suppress shrinkage of the laminated green sheet 21 in the direction of its main surface. As a result, the dimensional accuracy of the obtained laminate 1 (particularly, the conductor layers 9, 10, 11 and the via-hole conductor layer 12) is improved.

[0060] Chip components 13 and 14 may be mounted on the laminate 1 in a state where they are electrically connected to the conductor layer 10. In this way, an electronic component 2 having the laminate 1 is constructed.

[0061] Examples of the chip components 13 and 14 include an LC filter, a capacitor, an inductor, and the like.

[0062] The electronic component 2 may be mounted on a mounting substrate (for example, a motherboard) so as to be electrically connected via the conductor layer 11. [Example]

[0063] EXAMPLES Hereinafter, examples will be given that more specifically disclose the glass ceramics and multilayer ceramic electronic components of the present invention, but the present invention is not limited to these examples.

[0064] (A) Glass preparation Glasses G1 to G8 (all in powder form) with the compositions shown in Table 1 were produced by the following method. First, glass raw material powders were mixed and placed in a Pt-Rh crucible, and melted in an air atmosphere at 1650°C for at least 6 hours. The resulting melt was then rapidly cooled to produce cullets. The cullets were then coarsely crushed and placed in a container together with an organic solvent and PSZ balls (diameter: 5 mm), and mixed in a ball mill. By adjusting the crushing time during mixing in the ball mill, glass powder with a median particle size of 1.5 μm was obtained. Here, "median particle size" refers to the median particle size D50 measured by laser diffraction / scattering.

[0065] [Measurement of glass crystallization temperature] Each glass was measured using a differential scanning calorimeter DSC3300SA (manufactured by Netzsch) in the temperature range from room temperature to 1000° C., and the temperature of the exothermic peak was taken as the crystallization temperature. The results are shown in Table 1.

[0066] [Table 1]

[0067] (B) Preparation of green sheets Next, glass and aggregate were mixed in ethanol in a ball mill to form a slurry, with the composition shown in Table 2. The slurry was then mixed with a binder solution and a plasticizer dissolved in an organic solvent. The slurry was cast onto a PET film with a doctor blade and dried at 40°C to obtain a green sheet 25 microns thick. Of the aggregates, SiO2 is quartz with a median particle size of 1 μm, and Al2O3 is particles with a median particle size of 0.5 microns.

[0068] (C) Preparation and evaluation of evaluation samples (1) Dielectric constant and Q value (reciprocal of dielectric loss) To prepare a sample for evaluating the relative permittivity and Q value (the inverse of dielectric loss) of the glass ceramics, 30 green sheets were cut to 78 mm x 58 mm and stacked together, placed in a mold, pressed together with a press, and then cut to 50 mm x 50 mm. After that, the sample was fired at 980°C for 60 minutes in a reducing atmosphere. The laminates obtained by firing are shown in Table 2 as ceramics L1 to L29. In Table 2, the ceramics L6, L7, L12, L13, and L21 marked with an * are not laminates using the glass ceramics of the present invention. After firing, the thickness of the sample was measured, and the relative permittivity and Q value (the reciprocal of the dielectric loss) at 6 GHz were measured using the perturbation method. The following equipment was used to measure the relative permittivity and Q value. A relative permittivity of 5.0 or less and a Q value of 500 or more were considered good.

[0069] [Measurement equipment and conditions] Network analyzer: Keysight 8757D Signal generator: Keysight Synthesized Sweeper 83751 Resonator: Homemade jig (resonant frequency: 6GHz) Prior to the measurement, the cable loss was measured by connecting a network analyzer and a signal generator. The resonator was also calibrated using a standard substrate (quartz, dielectric constant: 3.73, Q value: 4545@6GHz, thickness: 0.636mm).

[0070] (2) Thermal expansion coefficient α For each of the ceramics L1 to L29, a Dilatometer TD5000SE (manufactured by Netzsch) was used to determine the thermal expansion coefficient α in the temperature range from room temperature to 600° C. A thermal expansion coefficient α of 6.0 ppm / K or more was considered good.

[0071] (3) Transverse bending strength Each of the ceramics L1 to L29 was subjected to a three-point bending test in accordance with JIS R1601 using an autograph AGS-5kNX manufactured by Shimadzu Corporation.

[0072] (4) Crystalline phase measurement For each of the ceramics L1 to L29, the fired samples were crushed into powder and analyzed by X-ray diffraction (XRD). The symbols for the XRD crystal phases shown in Table 2 are Q: SiO2 (quartz), G: ZnAl2O4 (gahnite), A: Al2O3, and W: Zn2SiO4 (willemite).

[0073] [Table 2]

[0074] The results in Table 2 show that the laminate including the glass ceramic layer that is a sintered body of the glass ceramic of the present invention has a low relative permittivity, a high Q value (low dielectric loss), and a large thermal expansion coefficient.

[0075] L6 had a low thermal expansion coefficient α, which is thought to be due to the aggregate SiO2 content being less than 20 wt%. L7 was insufficiently sintered, likely due to the glass content being less than 45% by weight and the SiO2 content of the aggregate exceeding 50% by weight. L12 was also undersintered, likely due to the glass content being less than 45 wt %. L13 also showed insufficient sintering, which is thought to be due to the Al2O3 content of the aggregate exceeding 20 wt%. L21 has a high relative permittivity and a low Q value, which is thought to be due to the ZnO content of the aggregate exceeding 10% by weight.

[0076] L3, L5, L6, L8-11, L14, L15, and L17-29, which contain Al2O3 as aggregate and have been successfully sintered, had a bending strength exceeding 150 MPa.

[0077] (5) Measurement of dielectric properties in the millimeter wave band TE conforming to JIS R 1641 for ceramic L1, L3, L5, L14 011 The relative permittivity and Q value (the reciprocal of the dielectric loss) were measured in the millimeter wave band (30 GHz) using the modal cavity resonator method. The results are shown in Table 3.

[0078] [Table 3]

[0079] The results shown in Table 3 show that each glass ceramic has a small dielectric constant and a high Q value even at millimeter-wave frequencies (approximately 30 GHz). For use as an electronic component for the millimeter wave band, it is more preferable that the dielectric constant is 4.5 or less and the Q value is 800 or more. In this way, the glass ceramic of the present invention is a material suitable for electronic components for the millimeter wave band.

[0080] In addition, in another embodiment of the glass ceramic of the present invention, the contents of Si, B, Al, and Zn are specified without distinguishing between glass and aggregate in one embodiment of the glass ceramic. However, the ratio of each element in the glass ceramic in the above examples can be calculated from the glass composition shown in Table 1 and the glass ceramic composition shown in Table 2. Each element is expressed as its oxide. For example, ceramic L3 contains 70.0 wt% glass G1 and 25.0 wt% SiO2 and 5.0 wt% Al2O3 as aggregates. The SiO2 content of ceramic L3 is the sum of the SiO2 content in glass G1 and the aggregate content, which is 70.0 × 59.4 / 100 + 25.0 = 66.58 wt%. Similarly, B2O3 is 70.0 × 18.8 / 100 = 13.16 wt%, Al2O3 is 70.0 × 10.9 / 100 + 5.0 = 12.63 wt%, and ZnO is 70.0 × 10.9 / 100 = 7.63 wt%. Table 4 shows the calculated ratios of each element in several glass-ceramics.

[0081] [Table 4]

[0082] As shown in Table 4, other embodiments of the glass ceramics of the present invention have a low B2O3 content, which makes it difficult for boron to be eluted from the glass ceramics after firing, and therefore, is less likely to cause problems such as a decrease in plating solution resistance. In addition, the glass ceramics have a high SiO2 content and low Al2O3 and ZnO contents, which allows for a low dielectric constant. The glass ceramic preferably contains 60% by weight or more of SiO2, 15% by weight or less of B2O3, 15% by weight or less of Al2O3, and 12% by weight or less of ZnO, which makes it possible to reduce the relative dielectric constant to 5 or less, and further to 4.5 or less. [Explanation of symbols]

[0083] 1. Laminate 2. Electronic Components 3 Glass-ceramic layers 9, 10, 11 Conductor layers 12 Via hole conductor layer 13, 14 Chip components 21 Laminated green sheet 22 Green Sheet

Claims

1. A glass ceramic comprising a glass containing Si, B, Al, and Zn, and an aggregate, The glass is contained in an amount of 45% by weight or more and 80% by weight or less, The aggregate contains 20% by weight or more and 50% by weight or less of SiO based on the weight of the glass ceramic. ２ and 20 wt. % or less of Al ２ O ３ and 10 wt % or less of ZnO, and a crystalline phase of SiO ２ , ZnAl ２ O ４ , and Al ２ O ３ Including, The glass has a SiO 2 content of 15% by weight or more and 65% by weight or less, The content of B 2 O 3 is 11% by weight or more and 30% by weight or less, the weight ratio of SiO 2 to B 2 O 3 (SiO 2 / B 2 O 3 ) is 1.21 or more; the weight ratio of Al 2 O 3 to ZnO (Al 2 O 3 / ZnO) is 0.75 or more and 1.64 or less; A glass-ceramic wherein the crystalline phase contains quartz as SiO 2 .

2. Al as the aggregate ２ O ３ The glass ceramic according to claim 1, comprising 1% by weight or more of

3. 2. The glass-ceramic according to claim 1, which does not contain any of MgO, CaO, SrO, and BaO.

4. The glass is a crystallized glass, and the crystalline phase precipitated from the glass is ZnAl ２ O ４ 2. The glass-ceramic of claim 1, comprising:

5. The glass contains Li as a secondary component. ２ Contains O, The glass contains Li ２ 2. The glass ceramic according to claim 1, wherein the O content is 1.0 wt % or less.

6. 2. The glass ceramic according to claim 1, wherein the crystallization temperature of the glass is 1000° C. or lower.

7. 2. The glass ceramic according to claim 1, having a relative dielectric constant of 5 or less.

8. A glass ceramic comprising Si, B, Al and Zn, SiO ２ The content is 52.00% by weight or more and 71.58% by weight or less, B ２ O ３ The content is 6.30% by weight or more and 21.00% by weight or less, Al ２ O ３ The content is 7.63% by weight or more and 22.00% by weight or less, The ZnO content is 5.04 wt% or more and 17.00 wt% or less, Contains no Li 2 O or not more than 0.55% by weight of Li 2 O, SiO as a crystalline phase ２ , ZnAl ２ O ４ , and Al ２ O ３ Including, A glass-ceramic wherein the crystalline phase contains quartz as SiO 2 .

9. 9. The glass-ceramic according to claim 8, which does not contain any of MgO, CaO, SrO, and BaO.

10. An electronic component comprising a glass ceramic layer which is a sintered body of the glass ceramic according to any one of claims 1 to 9.

11. the electronic component includes an electrode made of a metal containing Cu, 11. The electronic component according to claim 10, wherein the glass ceramic layer contains 0.5% by weight or less of Cu calculated as CuO.

Images