Glass, glass powder, mixed powder, glass paste, and green sheet

Abstract

To provide a glass exhibiting superior water resistance and allowing pulverization in an aqueous system.SOLUTION: A glass has a composition, expressed in mol% on an oxide basis, satisfying the following: SiO2: more than 10.0% and less than 49.0%, B2O3:more than 0% and 34.0% or less, WO3: more than 0% and 1% or less, Al2O3: 0% or more and 0.5% or less, CaO: 35.0% or more and 60.0% or less, ZnO: 0% or more and 4.0% or less, MgO: 0% or more and 4.0% or less, BaO: 0% or more and 4.0% or less, and SrO: 0% or more and 4.0% or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to glass. The present invention also relates to a glass powder obtained by pulverizing the glass, as well as a mixed powder, a glass paste, and a green sheet each containing the glass powder. do. [Background technology]

[0002] Low temperature co-fired ceramics (LTCC) and the like are known as multilayer circuit boards used at high frequencies above the GHz band. Low-temperature co-fired ceramics are made by adding glass-based materials to ceramic fillers such as alumina, and can be fired at lower temperatures than conventional ceramic substrates, resulting in ceramic multilayer substrates that integrate low-resistance conductors such as silver or copper with the ceramic substrate. This allows for multilayer substrates with low conductor resistance and excellent electrical properties, and they have advantageous high-frequency characteristics. In addition, because the substrate is ceramic, they have excellent heat and moisture resistance, and their high density also means they have excellent gas barrier properties.

[0003] Due to the above properties, LTCC ceramics are widely used in high-frequency modules, substrates for semiconductor packages, circuit boards and package substrates for applications requiring environmental resistance such as vehicles, and small passive elements.

[0004] Therefore, low-latency communication, reduced parasitic capacitance, and high gain characteristics are required for the glass that makes up the low-temperature co-fired ceramics, and for these reasons, electrical properties such as low dielectric constant and dielectric loss are desired.

[0005] In contrast to this, Patent Document 1 discloses a low-temperature fired glass ceramic containing a large amount of alkaline earth metal as a glass ceramic material having a low relative dielectric constant and low dielectric loss.

[0006] However, for multilayer circuit boards, not only the above electrical properties but also finer glass ceramic raw material powders are required for various purposes, such as reducing the thickness between layers to make them smaller, reducing the distance between wirings to make them denser, and improving functionality.

[0007] To meet these requirements, dry classification of glass that constitutes glass-ceramics generally tends to be inefficient due to the low specific gravity of glass compositions used in multilayer circuit boards. Furthermore, coarse particles of several tens of micrometers in size, known as "flying dust," tend to be mixed in. Furthermore, when using glass compositions with high hardness, the process of fine particle refinement can be difficult. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 5-238813 [Patent Document 2] Patent No. 5022675 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, the use of wet grinding for glass has been considered, but conventional glass ceramics such as those disclosed in Patent Document 1 have low moisture resistance and tend to aggregate easily, making them incompatible with water used as a dispersion medium. Therefore, it is necessary to use an organic solvent-based dispersion medium such as alcohol. However, from the viewpoints of reducing the cost of dispersion media, curbing global warming, preventing air pollution, and reducing health hazards, the use of organic solvents should be reduced.

[0010] Therefore, Patent Document 2 discloses a glass composition that can be crushed in an aqueous system and has low loss. However, the glass composition contains La2O3 and P2O5, of which La2O3 is expensive. Furthermore, the use of orthophosphoric acid to incorporate P2O5 raises safety and environmental concerns, and the use of phosphate-based composite oxides is expensive.

[0011] An object of the present invention is to provide a novel glass that has excellent water resistance and can be pulverized in an aqueous system, as well as a glass powder obtained by pulverizing the glass, and a mixed powder, a glass paste, and a green sheet that contain the glass powder. [Means for solving the problem]

[0012] As a result of extensive research, the present inventors have discovered that by adding an appropriate amount of WO to borosilicate glass of a predetermined composition, the above-mentioned object can be achieved without using expensive raw materials or raw materials that pose safety or environmental concerns, and have thus completed the present invention. That is, the gist of the present invention is as follows. [1] The composition in mole percent on an oxide basis is: SiO2: more than 10.0% and less than 49.0% B2O3: more than 0% and less than 34.0%, WO3: more than 0% and less than 1%, Al2O3: 0% or more and 0.5% or less, CaO: 35.0% or more and 60.0% or less, ZnO: 0% or more and 4.0% or less, MgO: 0% or more and 4.0% or less, BaO: 0% or more and 4.0% or less, and SrO: 0% or more and 4.0% or less, satisfies the above requirement, glass. [2] The glass according to [1] above, wherein the composition further satisfies the total content of Li2O, Na2O, and K2O: 0% or more and 0.15% or less. [3] The glass according to [1] or [2], wherein the composition further satisfies CuO: 0% or more and 1.0% or less. [4] The glass according to any one of [1] to [3] above, wherein the composition further satisfies CeO2: 0% or more and 1.0% or less. [5] The glass according to any one of [1] to [4] above, wherein the composition further satisfies the following: the total content of ZnO, MgO, CaO, SrO, and BaO: more than 41.0% and less than 55.0%. [6] The glass according to any one of the above [1] to [5], which is substantially free of lead. [7] The glass according to any one of [1] to [6] above, wherein the glass is powdered and fired in air at 850°C for 15 minutes to obtain a fired body, which contains CaSiO3 crystals. [8] The glass according to any one of [1] to [7] above, wherein in a powder X-ray diffraction pattern of a fired body obtained by powdering the glass and firing the powder at 850°C in air for 15 minutes, the relationship Z>X and Z>Y is satisfied, where X is the peak intensity at 2θ=26.6°±0.5° due to SiO2, Y is the peak intensity at 2θ=29.6°±0.5° due to CaB2O4, and Z is the peak intensity at 2θ=30.0°±0.5° due to CaSiO3.

[0013] [9] A glass powder obtained by pulverizing the glass according to any one of [1] to [8] above.

[10] A glass composition comprising the glass powder according to [9] above and, optionally, an amorphous glass filler mainly composed of SiO2, The mixed powder has a content of the glass powder of 50% by mass or more and 100% by mass or less based on the total content of the glass powder and the amorphous glass filler.

[11] The mixed powder according to

[10] , wherein the crystallization peak temperatures include a first crystallization peak temperature (Tc1) and a second crystallization peak temperature (Tc2) higher than the first crystallization peak temperature (Tc1).

[12] The mixed powder according to

[11] , wherein the first crystallization peak temperature (Tc1) is 850°C or less, and the second crystallization peak temperature (Tc2) is higher than 850°C.

[13] The mixed powder is fired in air at 850°C for 15 minutes to obtain a fired body having an average linear expansion coefficient of 50 × 10 at 50 to 350°C. -7~100×10 -7 The mixed powder according to any one of the above

[10] to

[12] , wherein the temperature is / °C.

[14] The mixed powder according to any one of the above

[10] to

[13] , having an average particle size (D50) of 2.0 μm or less.

[0014]

[15] A glass composition comprising the glass powder according to [9] above and, optionally, an amorphous glass filler mainly composed of SiO2, a glass paste in which the content of the glass powder is 50% by mass or more and less than 100% by mass based on the total content of the glass powder and the amorphous glass filler;

[16] A glass composition comprising the glass powder according to [9] above, an amorphous glass filler containing SiO2 as a main component, and a resin binder, The green sheet has a glass powder content of 50% by mass or more and less than 100% by mass based on the total of the glass powder and the amorphous glass filler. [Effects of the Invention]

[0015] The glass according to the present invention has excellent water resistance and can be pulverized in an aqueous system, without using expensive raw materials or raw materials that are of safety or environmental concern. Furthermore, glass ceramics obtained using the glass powder pulverized in an aqueous system can achieve good electrical properties such as a low dielectric constant and a low dielectric loss. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is an XRD pattern of Glass 1-3 of Example 1-3, which is an embodiment. [Figure 2] FIG. 2 is an XRD pattern of Glass 1-21 of Example 1-21, which is a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the embodiments described below.

[0018] Glass The glass according to this embodiment satisfies the following composition in mole percent based on oxides. SiO2: more than 10.0% and less than 49.0% B2O3: more than 0% and less than 34.0%, WO3: more than 0% and less than 1%, Al2O3: 0% or more and 0.5% or less, CaO: 35.0% or more and 60.0% or less, ZnO: 0% or more and 4.0% or less, MgO: 0% or more and 4.0% or less, BaO: 0% or more and 4.0% or less, and SrO: 0% or more and 4.0% or less.

[0019] When conventional borosilicate glass is crushed using water as a dispersion medium, the resulting slurry becomes creamy and the glass cannot be crushed. In contrast, the glass according to the present embodiment contains more than 0% and 1% or less of WO3, making it possible to crush the glass using water as a dispersion medium.

[0020] The reason for this is unclear, but it is thought that adding WO3 improves the dispersibility of glass in water and its chemical durability, stabilizing the slurry. Specifically, WO3 takes the form of a hydrate in water, but is insoluble in water, forming a water-insoluble barrier.

[0021] In addition to the above, it was found that the glass according to this embodiment can also achieve good electrical properties by adding WO3. Therefore, the glass according to this embodiment and a conventional glass not containing WO3 were crushed and fired in air at 850°C for 15 minutes to obtain fired bodies, and powder X-ray diffraction (XRD) measurements were performed on the fired bodies. As a result, it was found that there was a difference in the crystals that precipitated.

[0022] In the obtained XRD pattern, if the peak intensity derived from SiO2 is designated as X, the peak intensity derived from CaB2O4 as Y, and the peak intensity derived from CaSiO3 as Z, the relationship X>Y>Z can be seen in fired bodies obtained from conventional glass that does not contain WO3. In contrast, in the fired body obtained from the glass according to this embodiment, the relationship Z>Y is observed. Furthermore, no peaks derived from SiO2 are observed, or even if they are, the relationship is Z>X. The peak attributable to SiO2 is observed at 2θ = 26.6° ± 0.5°, the peak attributable to CaB2O4 is observed at 2θ = 29.6° ± 0.5°, and the peak attributable to CaSiO3 is observed at 2θ = 30.0° ± 0.5°.

[0023] Here, quartz (SiO2) is a crystal with a low dielectric constant and low dielectric loss, but when SiO2 crystallizes alone, much of the SiO2 in the glass components is consumed, making it difficult to precipitate CaSiO3, which has properties such as low dielectric loss. This results in a relatively high CaO content in the remaining glass that did not crystallize, which is thought to result in an increase in the dielectric constant and dielectric loss.

[0024] In contrast, in the glass according to this embodiment, WO3 acts as a crystal nucleus effective for the precipitation of CaSiO3 during the formation of the fired body, promoting the precipitation of CaSiO3 crystals. As a result, SiO2 precipitation is suppressed, the CaO content in the residual glass becomes relatively low, and it is believed that good electrical properties can be obtained due to the CaSiO3. This is the effect of including WO3, and it can make the crystal precipitation state of the resulting fired body favorable.

[0025] It is also possible to add CaSiO3 crystals themselves as seed crystals to precipitate CaSiO3 crystals. However, because CaSiO3 crystals have a needle-like shape, there are concerns about their health hazards, and handling them in powder form is problematic. In contrast, adding WO3 is a groundbreaking method that also takes safety into consideration.

[0026] As described above, the glass according to this embodiment is preferably sintered and used as a fired body, more preferably used together with a filler, and more preferably used in glass ceramics.

[0027] The specific composition of the glass according to this embodiment will be described below in order, where the content of each component is expressed in mole percent on an oxide basis.

[0028] In the glass according to this embodiment, SiO2 is an essential component for forming stable glass and for crystal precipitation when the glass is fired. It also enhances the chemical durability of the glass. When the glass is fired, the precipitation of CaSiO3 crystals reduces dielectric loss. The SiO2 content is more than 10.0% and less than 49.0%. From the viewpoints of increasing the stability of the glass, realizing good chemical durability, and facilitating the precipitation of wollastonite (CaSiO3), the content is more than 10.0%, preferably 29.5% or more, and more preferably 38.0% or more. Precipitating CaSiO3 can achieve low dielectric loss and also relatively reduce the amount of precipitation of calcium borate crystals, which have a high dielectric constant, thereby achieving a low dielectric constant. Furthermore, from the viewpoints of increasing the stability of the glass, suppressing excessive precipitation of CaSiO3, and suppressing devitrification and a decrease in sinterability, the content is less than 49.0%, preferably 48.0% or less, and more preferably 45.0% or less.

[0029] In the glass according to this embodiment, B2O3 is a flux component that improves the meltability and low-temperature sinterability of the glass, and is also a constituent of calcium borate crystals, which are secondary crystals. While B2O3 is a component that lowers the relative dielectric constant of a fired body, if the amount of precipitation of the calcium borate crystals becomes too high, the relative dielectric constant may become high. The B2O3 content is more than 0% and not more than 34.0%. From the viewpoints of meltability, low-temperature sinterability, and electrical properties, the content is more than 0%, preferably not less than 9.0%, and more preferably not less than 9.5%. Furthermore, from the viewpoints of chemical durability and preventing devitrification and reduced sinterability due to excessive precipitation of calcium borate-based crystals accompanying reduced glass stability, the content is not more than 34.0%, preferably not more than 24.5%, more preferably not more than 20.0%, and even more preferably not more than 17.5%.

[0030] In the glass according to this embodiment, WO is an essential component that enhances chemical durability, such as moisture resistance and plating solution resistance, and also acts as a crystal nucleus, as described above, contributing to low dielectric loss. The WO3 content is greater than 0%, and preferably greater than 0% and 1% or less. Here, even a trace amount of WO3 can be added to produce an effect, and the greater the content, the better the properties. Therefore, the content is greater than 0% and preferably 0.1% or more. Furthermore, from the viewpoint of suppressing devitrification, the content is preferably 1% or less, more preferably less than 1%, even more preferably 0.7% or less, and even more preferably 0.5% or less.

[0031] In the glass according to this embodiment, Al2O3 is a component that reduces the crystallinity of the glass, facilitating glass manufacturing and improving chemical durability. However, in the composition of the glass according to this embodiment, Al2O3 is a component that is likely to increase electrical properties, particularly dielectric loss. The content of Al2O3 is 0 to 0.5%. Here, the content is 0.5% or less, preferably less than 0.5%, more preferably 0.2% or less, and even more preferably 0%, i.e., substantially no content. In this specification, "substantially free" means that a content of approximately 0.1% or less is acceptable as an unavoidable content of raw material impurities, etc. Furthermore, when Al2O3 is contained in a glass ceramic using the glass according to this embodiment, the Al2O3 may be mixed in from the filler or grinding member that constitutes the glass ceramic. In this case, it is necessary to distinguish whether the Al2O3 is a component derived from the glass or a component derived from other sources such as the filler or grinding member. The amount mixed in from the grinding member is generally 0.5% or less.

[0032] In the glass according to this embodiment, CaO is a constituent of the crystals that precipitate when the glass is fired, namely, the main crystal, wollastonite (CaSiO3), and the secondary crystal, calcium borate crystals, and can be said to be an essential component for crystal precipitation. CaO is also a flux component for achieving low-temperature sintering. On the other hand, it is also a component that increases the relative dielectric constant compared to SiO2 and BO3. The CaO content is 35.0 to 60.0%. From the viewpoint of suppressing an increase in the melting temperature or devitrification temperature and preventing devitrification, the CaO content is 35.0% or more, preferably more than 41.0%, and more preferably more than 43.0%. Furthermore, from the viewpoint of preventing the glass from becoming unstable and devitrifying, the CaO content is 60.0% or less, preferably less than 55.0%, more preferably 50.0% or less, and even more preferably 45.0% or less.

[0033] In the glass according to this embodiment, part of the CaO may be substituted with ZnO, MgO, BaO, or SrO. In this case, it is preferable that the total content of CaO, ZnO, MgO, BaO, and SrO satisfies the above range. That is, the content is preferably 35.0 to 60.0%, and more preferably more than 41.0% and less than 55.0%. Here, the total content is preferably 35.0% or more, more preferably more than 41.0%, even more preferably more than 43.0%, and is preferably 60.0% or less, more preferably less than 55.0%, even more preferably 50.0% or less, and even more preferably 45.0% or less.

[0034] The content of each of ZnO, MgO, BaO and SrO is 0 to 4.0%, preferably 0 to less than 4.0%, and more preferably 0 to 2.0% or less. The total content of ZnO, MgO, BaO and SrO is preferably 0 to 4.0%, more preferably 0 to less than 4.0%, and even more preferably 0 to 2.0%.

[0035] In the glass according to this embodiment, alkali metal oxides are effective components for suppressing substrate deformation due to reactions with co-fired metal conductors such as Ag and Cu and for preventing poor glass penetration into the conductors when preparing the glass-ceramics. However, they are also components that tend to increase electrical properties, particularly dielectric loss. Therefore, it is preferable to limit the amount of alkali metal oxide used. The total content of alkali metal oxides is preferably 0 to 0.15%, and the total content is preferably 0.15% or less, and more preferably 0.10% or less. Even when alkali metal oxides are not used intentionally, they may be contained in a total amount of about 0.05% as impurities in the natural minerals that are the glass raw materials or as impurities in the refining process.

[0036] Moreover, the total content of Li2O, Na2O and K2O as alkali metal oxides is more preferably 0 to 0.15%, and even more preferably 0 to 0.10%. When alkali metal oxides are contained, it is preferable to use a combination of multiple alkali metal oxides, since the mixed alkali effect can minimize deterioration of electrical properties. In this case, the combination of Li2O and Na2O is most preferable.

[0037] In the glass according to this embodiment, CuO is not an essential component, but when it is made into a glass ceramic, it is a component that can suppress coloration of the glass ceramic substrate due to electrode diffusion. The CuO content is preferably 0 to 1.0%. From the viewpoint of suppressing foaming, the content is preferably 1.0% or less, and more preferably 0.5% or less. It should be noted that CuO is not a raw material for adjusting the glass composition, and the same effect can be obtained by adding CuO crystal powder in an amount other than the specified amount to the obtained glass powder. Furthermore, although a portion of CuO may exist in a state reduced to Cu2O, the above contents are shown as values ​​converted into CuO for both CuO and Cu2O.

[0038] In the glass according to this embodiment, CeO2 is not an essential component, but when it is made into a glass ceramic, it is a component that can suppress coloration of the glass ceramic substrate due to diffusion of the electrodes. The content of CeO2 is preferably 0 to 1.0%. From the viewpoint of suppressing foaming, the content is preferably 1.0% or less, and more preferably 0.5% or less. Note that CeO2 is not a raw material for adjusting the glass composition, and the same effect can be obtained by adding CeO2 powder in an amount other than the specified amount to the obtained glass powder. In addition, some of the CeO2 may exist in a reduced state as a metastable phase such as Ce2O3, but the above content is shown as a value converted to CeO2 for both CeO2 and Ce2O3.

[0039] From the viewpoint of reducing the environmental load, the glass according to this embodiment preferably contains substantially no lead. Here, "substantially no lead" means, as mentioned above, that a content of about 0.1% or less of PbO as unavoidable raw material impurities is acceptable.

[0040] The glass according to this embodiment may contain other components in addition to those described above, provided that the effects of the present invention are not significantly impaired. Examples of other components include ZrO2, Ag2O, CoO, MoO3, MnO, Sb2O3, FeO, SnO, and La2O3, but these are merely examples, and the other components that the glass of this embodiment may contain are not limited to these. Of the above, CoO, MoO3, MnO, and FeO can be coloring components. The above CoO includes Co3O4, the above MnO includes MnO2, the above Sb2O3 includes Sb2O5, the above FeO includes Fe2O3, and the above SnO includes SnO2. The total content of other components that may be contained is preferably 5% or less, more preferably 3% or less.

[0041] The true specific gravity of the glass according to this embodiment is preferably 2.70 to 3.00. From the viewpoint of reducing the weight of electronic circuit boards and the like using the glass according to this embodiment, the true specific gravity is preferably 3.00 or less, more preferably 2.95 or less, and even more preferably 2.90 or less. Due to the characteristics of the glass composition, the true specific gravity is 2.70 or more, and typically 2.80 or more. In this specification, the true specific gravity of glass means a value measured by Archimedes' method.

[0042] In the glass according to this embodiment, the fired body obtained by sintering preferably contains CaSiO3 crystals. As described above, the CaSiO3 crystals have good electrical properties, such as low dielectric loss. In the glass according to this embodiment, when the fired body is formed, WO3 acts as a crystal nucleus effective for the precipitation of CaSiO3, promoting the precipitation of CaSiO3 crystals. As a result, SiO2 precipitation is suppressed, the CaO content in the residual glass becomes relatively low, and it is believed that good electrical properties due to CaSiO3 can be obtained. The fired body means a body obtained by firing glass powder obtained by crushing glass in the atmosphere at 850° C. for 15 minutes.

[0043] More specifically, the glass according to this embodiment preferably exhibits a peak derived from CaSiO3 in the powder X-ray diffraction (XRD) pattern of the sintered body obtained by sintering. The peak derived from CaSiO3 is usually observed at 2θ=30.0°±0.5°.

[0044] In the above XRD pattern, when the peak intensity at 2θ = 26.6° ± 0.5° due to SiO2 is defined as X, the peak intensity at 2θ = 29.6° ± 0.5° due to CaB2O4 is defined as Y, and the peak intensity at 2θ = 30.0° ± 0.5° due to CaSiO3 is defined as Z, it is preferable that the relationship Z > X is satisfied, and it is more preferable that the relationships Z > X and Z > Y are satisfied. However, it is not necessary that the peak at 2θ = 26.6° ± 0.5° due to SiO2 or the peak at 2θ = 29.6° ± 0.5° due to CaB2O4, or the peak at 2θ = 26.6° ± 0.5° due to SiO2 is not observed.

[0045] The glass according to this embodiment is preferably pulverized and used as glass powder, that is, the glass powder according to this embodiment is obtained by pulverizing the glass according to this embodiment.

[0046] The glass according to this embodiment can be pulverized in an aqueous system. That is, when water is used as a dispersion medium, the resulting glass slurry does not become creamy and can be suitably pulverized.

[0047] The method for producing the glass according to this embodiment is not particularly limited, but examples thereof include the following method.

[0048] First, raw materials are mixed to prepare a raw material mixture. The raw materials are not particularly limited as long as they are raw materials used in the production of ordinary oxide-based glasses, and oxides, carbonates, etc. can be used. The raw material mixture is prepared by appropriately adjusting the types and proportions of the raw materials so that the composition of the resulting glass falls within the aforementioned range.

[0049] Next, the raw material mixture is heated by a known method to obtain a melt. The heating temperature (melting temperature) is preferably, for example, 1450 to 1600°C. Here, the heating temperature is preferably 1450°C or higher, more preferably 1500°C or higher. Also, the heating temperature is preferably 1600°C or lower, more preferably 1550°C or lower. The heating time is preferably, for example, 90 to 180 minutes. The heating time is preferably 90 minutes or more, more preferably 100 minutes or more, and is preferably 180 minutes or less, more preferably 140 minutes or less.

[0050] Thereafter, the melt is cooled and solidified to obtain the glass according to this embodiment. The cooling method is not particularly limited, and for example, cooling can be performed using a roll-out machine, a press machine, etc., or rapid cooling can be performed by dropping the material into a cooling liquid, etc.

[0051] The glass according to this embodiment obtained as described above may be in any form, such as a block, a plate, a thin plate (flake), or a powder.

[0052] 《Mixed powder》 The mixed powder according to this embodiment preferably contains a glass powder and optionally further contains an amorphous glass filler. Here, the glass powder may be a glass powder obtained by pulverizing the glass described in the above "Glass," and the preferred aspects are the same. Furthermore, the mixed powder according to this embodiment may consist solely of glass powder, or may consist solely of glass powder obtained by pulverizing the glass described in the above "Glass." Furthermore, the preferred ranges for the physical properties of the mixed powder according to this embodiment are also the preferred ranges for the physical properties of the glass that constitutes the glass powder that constitutes the mixed powder.

[0053] The amorphous glass filler preferably contains SiO2 as a main component. Here, "main component" means that the content of the SiO2 in all components constituting the filler is 50 mol% or more, and the SiO2 content is preferably 50 to 100 mol%, more preferably 70 to 100 mol%, and even more preferably 70 to 95 mol% or 95 to 100 mol%. Here, the SiO2 content is preferably 50 mol% or more, more preferably 70 mol% or more, more preferably 80 mol% or more, and may be 95 mol% or more. Furthermore, the SiO2 content may be 100 mol% or less, less than 100 mol%, or 95 mol% or less.

[0054] The amorphous glass filler has a very high viscosity, and when the viscosity change with temperature becomes gradual, it functions as a filler material until the glass powder used together crystallizes, and at higher temperatures, its softening fluidity increases and it functions as a sintering aid. From this perspective, the content of the SiO2 is preferably 70 to 95 mol%. Examples of such amorphous glass fillers include borosilicate glass such as D glass, a glass material for long glass fibers (glass fibers), and IWAKI CTE33 (manufactured by AGC Corporation).Also, borosilicate glass not containing Al2O3, as disclosed in Japanese Patent No. 4228344, may be used.

[0055] The amorphous glass filler may have an SiO2 content of 95 mol % or more. Examples of such a filler include quartz glass, commonly known as fused silica, and Vycor (registered trademark, manufactured by Corning Incorporated) glass, which is similar to quartz glass. Such amorphous glass fillers function perfectly as fillers, exhibiting virtually no softening or fluidity at temperatures below 1000°C. In addition, they contain little impurities such as B2O3 and alkali metal oxides, and therefore have excellent electrical properties.

[0056] The amorphous glass filler of this embodiment may contain other components within the range that does not impair the desired effects, such as Al2O3, alkali metal oxides, alkaline earth metal oxides, and components having properties similar to those of Al2O3, ZnO, etc.

[0057] In the amorphous glass filler of this embodiment, Al2O3 may reduce crystallinity and increase dielectric loss, so the Al2O3 content is preferably 10 mol% or less, more preferably 5 mol% or less, even more preferably 2 mol% or less, even more preferably 0.5 mol% or less, and even more preferably substantially zero.

[0058] In the amorphous glass filler of this embodiment, alkali metal oxides may worsen dielectric loss. Therefore, the total content of alkali metal oxides is preferably 3 mol% or less, more preferably 2 mol% or less, even more preferably 1 mol% or less, and even more preferably substantially none. On the other hand, when alkali metal oxides are contained, it is preferable to contain multiple alkali metal oxides in order to expect a mixed alkali effect. Here, preferred alkali metal oxides include Li2O, Na2O, and KO, and it is more preferable to contain two or more of these.

[0059] In the amorphous glass filler of this embodiment, alkaline earth metal oxides and components with properties similar thereto, such as ZnO, may be contained in a certain amount to improve wettability with the glass powder. However, this may degrade electrical properties. Therefore, the total content of the above components is preferably 5 mol % or less, more preferably 3 mol % or less, even more preferably 1 mol % or less, and even more preferably substantially none. Suitable alkaline earth metal oxides include MgO, CaO, SrO, and BaO.

[0060] The glass transition temperature (Tg) of the mixed powder according to this embodiment and the glass constituting the same is preferably 600°C or higher, more preferably 650 to 700°C. Here, from the viewpoint of not inhibiting the debinding treatment during the production of glass ceramics, the glass transition temperature (Tg) is preferably 600°C or higher, more preferably 650°C or higher. Further, from the viewpoint of sinterability, the glass transition temperature (Tg) is preferably 700°C or lower, more preferably 685°C or lower. In this specification, the glass transition temperature (Tg) is defined by the first inflection point of differential thermal analysis (DTA).

[0061] The glass softening point (Ts) of the mixed powder according to this embodiment and the glass constituting the same is preferably 800°C or lower, more preferably 700 to 800°C. Here, from the viewpoint of obtaining good sinterability, the glass softening point (Ts) is preferably 800°C or lower, more preferably 780°C or lower. Further, from the viewpoint of shrinkage matching with a metal conductor such as Ag or Cu, the glass softening point (Ts) is preferably 700°C or higher, more preferably 720°C or higher. In this specification, the glass softening point (Ts) is defined by the fourth inflection point of differential thermal analysis (DTA).

[0062] The mixed powder according to this embodiment and the glass constituting the same preferably have a crystallization peak temperature of 2 or more from the viewpoint of obtaining good sinterability and electrical characteristics. Thereby, even after one crystal is precipitated in the firing stage, an appropriate amount of residual glass can be left for a certain period of time during firing.

[0063] When the mixed powder according to this embodiment and the glass constituting the same have two or more crystallization peak temperatures, any two temperatures are taken as the first crystallization peak temperature (Tc1) and the second crystallization peak temperature (Tc2), and the second crystallization peak temperature (Tc2) is higher than the first crystallization peak temperature (Tc1), and has the relationship of Tc1 < Tc2. In this specification, the crystallization peak temperature (Tc) is defined by an exothermic peak at a temperature higher than the softening point of differential thermal analysis (DTA).

[0064] The first crystallization peak temperature (Tc1) is preferably 850°C or lower, more preferably 760 to 850°C. From the viewpoint of preventing a decrease in crystallinity due to excessive dissolution of the co-fired electrode material or filler into the mixed powder, the temperature is preferably 850°C or lower, more preferably 835°C or lower. From the viewpoint of sinterability, the temperature is preferably 760°C or higher, more preferably 800°C or higher, and even more preferably 810°C or higher.

[0065] The second crystallization peak temperature (Tc2) is preferably above 850°C, and more preferably above 850°C and not higher than 950°C. From the viewpoint of sinterability, the temperature is preferably above 850°C. Furthermore, from the viewpoint of suppressing excessive residual glass, the temperature is preferably not higher than 950°C, more preferably not higher than 900°C, and even more preferably not higher than 870°C.

[0066] The linear expansion coefficient of the mixed powder according to this embodiment and the glass constituting it is 50×10 -7 ~100×10 -7 / °C. Here, due to the characteristics of the precipitated crystals, the linear expansion coefficient is preferably 50×10 -7 / ℃ or more, 55 × 10 -7 / ℃ or more, 60 × 10 -7 / °C or more. In order to prevent the difference in thermal expansion coefficient between the glass ceramic substrate obtained using the glass according to this embodiment and semiconductor elements and other passive elements mounted on the substrate from becoming too large, the linear expansion coefficient may be 100×10 -7 / ℃ or less is preferable, and 80 × 10 -7 / ℃ or less. In this specification, the linear expansion coefficient refers to the average linear expansion coefficient at 50 to 350°C obtained by firing the mixed powder or a glass powder obtained by pulverizing the glass constituting the mixed powder at 850°C for 15 minutes in the air.

[0067] The particle size of the mixed powder according to this embodiment and the glass powder obtained by pulverizing the glass constituting the mixed powder preferably has an average particle size (D50) of 0.5 to 2.0 μm. Here, in order to suppress an increase in viscosity when made into a paste or slurry and from the viewpoint of ease of handling, the average particle size (D50) is preferably 0.5 μm or more, more preferably 1.0 μm or more. Furthermore, in terms of sinterability when made into a fired body and manufacturability of low-profile products, the average particle size (D50) is preferably 2.0 μm or less, more preferably 1.5 μm or less. In this specification, the average particle diameter (D50) means the median diameter at which the integrated amount of particles is 50% cumulatively from the smallest particle in a volume-based cumulative particle size distribution curve measured by laser diffraction.

[0068] The mixed powder according to this embodiment and the glass powder obtained by pulverizing the glass constituting the mixed powder preferably have a D10 value of 0.1 to 1.2 μm. From the viewpoint of paste or slurry dispersibility, D10 is preferably 0.1 μm or more, more preferably 0.5 μm or more, and even more preferably 0.6 μm or more. From the viewpoint of sinterability, D10 is preferably 1.0 μm or less, more preferably 0.9 μm or less, and even more preferably 0.7 μm or less. In this specification, D10 means the particle size at which the integrated amount is 10% cumulatively from the smallest particle in a volume-based cumulative particle size distribution curve measured by laser diffraction.

[0069] The mixed powder according to this embodiment or the glass powder obtained by pulverizing the glass constituting the mixed powder preferably has a value represented by D90 of 3.5 μm or less. From the viewpoint of reducing the thickness per layer of an electronic circuit board or the like using the mixed powder according to this embodiment or the glass powder, D90 is preferably 3.5 μm or less, more preferably 3.2 μm or less, and even more preferably 2.5 μm or less. The lower limit of the D90 is not particularly limited, but may be, for example, more than 0.5 μm. In this specification, D90 means the particle size at which the integrated amount, cumulatively accumulating from the smallest particle, accounts for 90% of the total in a volume-based cumulative particle size distribution curve measured by laser diffraction.

[0070] The value represented by Dmax of the mixed powder according to this embodiment or the glass powder obtained by pulverizing the glass constituting it is preferably 15 μm or less. Here, similar to D90, from the viewpoint of reducing the thickness per layer of an electronic circuit board or the like using the mixed powder according to this embodiment or the glass powder, Dmax is preferably 15 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less. The lower limit of Dmax is not particularly limited, but may be, for example, more than 0.5 μm. In this specification, Dmax means the particle size (maximum particle size) that is the maximum value in a volume-based cumulative particle size distribution curve measured by laser diffraction.

[0071] The shape of the amorphous glass filler in this embodiment is not particularly limited, but from the viewpoint of sinterability, for example, the average particle size (D50) is preferably 1 to 5 μm.

[0072] In the mixed powder according to this embodiment, the content of the glass powder relative to the total of the glass powder and the amorphous glass filler is preferably 50 to 100 mass %, and the content of the amorphous glass filler is preferably 0 to 50 mass %. The content of the glass powder is preferably 50% by mass or more, more preferably 75% by mass or more, and even more preferably 79% by mass or more. That is, the content of the amorphous glass filler is preferably 50% by mass or less, more preferably 25% by mass or less, and even more preferably 21% by mass or less. The content of the glass powder is 100% by mass, i.e., the amorphous glass filler is optional, but when an amorphous glass filler is contained, the content of the glass powder is less than 100% by mass, and may be 88% by mass or less, or 80% by mass or less. That is, the content of the amorphous glass filler is 0% by mass or more, may be more than 0% by mass, may be 12% by mass or more, or may be 20% by mass or more.

[0073] The mixed powder according to this embodiment preferably contains an amorphous glass filler containing SiO2 as a main component among the above amorphous glass fillers. In this case, the content of the glass powder relative to the total of the glass powder and the amorphous glass filler is 50 to 100 mass%, more preferably 50 mass% or more and less than 100 mass%.

[0074] The amorphous glass filler contained in the mixed powder according to this embodiment may be one type or two or more types, and two or more amorphous glass fillers containing SiO2 as the main component may be used in combination.

[0075] The mixed powder according to this embodiment may further contain other components in addition to the glass powder and amorphous glass filler. Examples of other components include inorganic oxide fillers, firing aids, and composite oxide pigments for coloring.

[0076] Examples of inorganic oxide fillers include alumina filler, magnesia filler, steatite, forsterite, cordierite, willemite, cerium oxide, zirconium oxide, copper oxide, and silver oxide.

[0077] Examples of firing aids include glass frit, lithium carbonate, sodium carbonate, potassium carbonate, calcium carbonate, barium carbonate, strontium carbonate, boric anhydride, and aluminum hydroxide. Here, the glass frit acts as a firing aid and is therefore different from the glass powder contained in the mixed powder according to this embodiment. Furthermore, the other components described above are merely examples, and the other components that can be contained in the mixed powder according to this embodiment are not limited to these.

[0078] Glass paste The glass paste according to the present embodiment preferably contains a glass powder, optionally an amorphous glass filler, and a vehicle. Here, the glass powder may be a glass powder obtained by pulverizing the glass described in the above "Glass," and the same applies to preferred embodiments. The amorphous glass filler may be an amorphous glass filler described in the above "Mixed Powder," and the same applies to preferred embodiments. That is, it can also be said that the glass paste according to the present embodiment preferably contains a mixed powder and a vehicle. In this case, the mixed powder may be the same as the "Mixed Powder," and the same applies to preferred embodiments. For example, the content of the glass powder relative to the total of the glass powder and the amorphous glass filler is preferably 50% by mass or more and 100% by mass or less.

[0079] The vehicle in this embodiment may be a conventionally known vehicle, such as a solution of methyl cellulose, ethyl cellulose, carboxymethyl cellulose, oxyethyl cellulose, benzyl cellulose, propyl cellulose, or nitrocellulose in a solvent such as terpineol, butyl carbitol acetate, or ethyl carbitol acetate, or a solution of an acrylic resin such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, or 2-hydroxyethyl methacrylate in a solvent such as methyl ethyl ketone, terpineol, butyl carbitol acetate, or ethyl carbitol acetate. In this specification, the term "(meth)acrylate" refers to at least one of acrylate and methacrylate.

[0080] The glass paste according to this embodiment may further contain other components, such as the inorganic oxide filler and firing aid described above in the "Mixed Powder" section.

[0081] The glass paste according to this embodiment is applied to a member to be coated (for example, the top layer of a green sheet laminate or the top surface of a ceramic substrate such as an LTCC substrate) by, for example, screen printing or the like, and then fired in an electric furnace or the like. The glass is sintered by this heating and becomes a glass ceramic, thereby forming a coating.

[0082] Green Sheet The green sheet according to this embodiment preferably contains a glass powder, optionally an amorphous filler, and optionally a resin binder. Here, the glass powder may be a glass powder obtained by pulverizing the glass described in the above "Glass," and the same applies to preferred embodiments. The amorphous glass filler may be an amorphous glass filler described in the above "Mixed Powder," and the same applies to preferred embodiments. That is, it can be said that the green sheet according to this embodiment preferably contains a mixed powder, and in this case, the mixed powder may be the above "Mixed Powder," and the same applies to preferred embodiments.

[0083] The green sheet according to this embodiment is one of the uses of the mixed powder described above in "Mixed Powder." Specifically, the green sheet is obtained by mixing glass powder with a resin binder to form a slurry, applying the resulting slurry onto a film, and drying the slurry.

[0084] At this time, additives such as plasticizers may be added as needed. Next, the mixture is mixed with a solvent to form a slurry, which is then formed into a sheet on a film such as polyethylene terephthalate. Finally, the sheet-formed slurry is dried to remove the solvent, resulting in a green sheet.

[0085] The resin is not particularly limited, and any resin that is normally used in the green sheet method may be used, such as polyvinyl butyral resin or acrylic resin. The plasticizer is not particularly limited, and any plasticizer that is normally used in the green sheet method may be used, such as dibutyl phthalate, dioctyl phthalate, butyl benzyl phthalate, etc. The solvent is not particularly limited, and any solvent that is normally used in the green sheet method may be used, such as toluene, xylene, or butanol. The method for molding the slurry is not particularly limited, but may be, for example, a doctor blade method.

[0086] On the obtained green sheet, wiring patterns and vias as through conductors may be formed as needed by screen printing or the like using silver paste, silver conductor, etc. Also, an overcoat glass for protecting the wiring, etc. made of silver may be formed by screen printing or the like. Thereafter, a plurality of green sheets are laminated as required, cut into a desired shape, and fired to obtain a fired body, that is, a glass ceramic substrate.

[0087] Glass ceramics The glass ceramic according to this embodiment can be obtained by firing a mixed powder or a glass paste containing a glass powder obtained by pulverizing the glass described in the above "Glass" and optionally an amorphous glass filler, preferably an amorphous glass filler containing SiO as a main component.

[0088] The glass ceramic according to this embodiment preferably achieves at least one of a low relative permittivity and a low dielectric loss as electrical properties, and more preferably achieves both. Specifically, the relative dielectric constant is preferably 7 or less, more preferably 6.5 or less, and the smaller the better, but is usually 4.5 or more. In addition, the dielectric loss in the GHz band is 20×10 -4 Less than 15 x 10 is preferable -4 Less than or equal to 3×10 is preferable, and smaller is better, but typically 3×10 -4 That's all.

[0089] The firing temperature for obtaining the glass ceramics according to this embodiment varies depending on the glass composition and the content of additives such as fillers, but is, for example, 800 to 1000° C. Here, the temperature may be 800° C. or higher, 820° C. or higher, or 850° C. or higher, or may be 1000° C. or lower, 950° C. or lower, or 900° C. or lower.

[0090] Furthermore, when firing is performed at such a high temperature that the precipitated crystalline phase is partially melted, the temperature may be lowered to about 820 to 850° C. after firing, and annealing may be performed again.

[0091] The firing time for obtaining the glass ceramics also varies depending on the glass composition and the content of additives such as fillers, but is, for example, 10 to 120 minutes. Here, the firing time may be 10 minutes or more, 15 minutes or more, or 30 minutes or more, or 120 minutes or less, 90 minutes or less, or 60 minutes or less.

[0092] The glass ceramic according to this embodiment preferably has small differences in electrical properties due to differences in firing temperature. For example, when the firing temperature differs by 50°C, the difference in relative permittivity is preferably within the range of ±0.2, more preferably within the range of ±0.1. Furthermore, the difference in dielectric loss in the above case is ±3×10 -4 The range of ±2×10 is preferable. -4 It is more preferable that the range is within the range of . [Example]

[0093] The present invention will be described in detail below using examples, but the present invention is not limited to the following examples as long as it does not deviate from the gist of the invention. Examples 1-1 to 1-19, 2-1 to 2-25, 2-27, and 2-28 are working examples, and Examples 1-20 to 1-23 and 2-26 are comparative examples.

[0094] <<Example 1-1 to Example 1-23>> Glass raw materials were prepared and mixed to obtain the glass compositions shown in Table 1, melted in a platinum crucible in an electric furnace at 1500°C for 2 hours, and quenched using a pair of stainless steel rolls to obtain flake-shaped Glasses 1-1 to 1-23.

[0095] "evaluation" <water resistance> The obtained glass flakes were crushed using water. Specifically, the material was milled in a ball mill using an alumina porcelain milling pot and partially stabilized zirconia ceramic balls with a diameter of 5 to 20 mm as the media, and ion-exchanged water was used as the dispersion medium in an amount 1.5 times (by weight) the amount of glass. The milling was carried out while measuring the particle size with a microtrack so that the average particle size (D50) would be 2 μm or less. In Table 1, "○" for "Water Resistance" means that it can be ground in an aqueous system and has excellent water resistance, and "×" means that it cannot be ground in an aqueous system and has poor water resistance. Specifically, Glasses 1-20 and 1-21 became highly viscous and creamy due to the addition of ion-exchanged water, and could not be pulverized, resulting in no glass powder being obtained. Glasses 1-22 and 1-23 were devitrified during production, and no glass was obtained, and are therefore marked with "-" in Table 1.

[0096] <True specific gravity> The true specific gravity of the obtained bulk glass was measured by Archimedes' method. Note that during glass production, the raw materials were melted to obtain the bulk glass in a manner that prevented the inclusion of air bubbles. The results are shown in Table 1. Blank spaces indicate that the measurement was not performed.

[0097] <Precipitated crystals> Glasses 1-3 and 1-21 were fired in air at 850° C. for 15 minutes, and the fired bodies were pulverized and subjected to XRD diffraction measurement under the following conditions. X-ray source: CuKα ray, tube voltage: 40 kV, tube current: 150 mA, scan angle: 10 to 80°, scan speed: 10° / min, number of steps: 0.02° / step.

[0098] In the XRD pattern of Glass 1-3, a peak due to SiO2 was observed at 2θ = 26.34°, a peak due to CaB2O4 at 2θ = 29.50°, and a peak due to CaSiO3 at 2θ = 30.04°. Furthermore, when the peak intensity due to SiO2 is designated as X, the peak intensity due to CaB2O4 as Y, and the peak intensity due to CaSiO3 as Z, the ratio represented by Z / X was 2.606, and the ratio represented by Z / Y was 1.607. In the XRD pattern of Glass 1-21, a peak due to SiO2 was observed at 2θ = 26.64°, a peak due to CaB2O4 at 2θ = 29.60°, and a peak due to CaSiO3 at 2θ = 30.12°. Furthermore, when the peak intensity due to SiO2 is designated as X, the peak intensity due to CaB2O4 as Y, and the peak intensity due to CaSiO3 as Z, the ratios Z / X and Z / Y were 0.196 and 0.581, respectively.

[0099] [Table 1]

[0100] <<Example 2-1 to Example 2-26>> An amorphous glass filler was added to each glass powder in the proportions shown in Tables 2 and 3, and the mixture was pulverized until the Dmax was 15 μm or less. The pulverization was performed using a ball mill using an alumina porcelain pulverization pot and partially stabilized zirconia ceramic balls with a diameter of 5 to 20 mm as the medium, and ion-exchanged water was used as the dispersion medium in an amount 1.5 times (by weight) the amount of glass. The average particle size (D50) of the SiO2 (fused silica) used as the amorphous glass filler was 5 μm, and the average particle size (D50) of the borosilicate glass was 1.0 μm. In Examples 2-11 and 2-12, no amorphous glass filler was used, and only the glass powder was used as is. Next, the mixture was filtered using a fluororesin membrane filter to separate it from the ion-exchanged water, and the filtered residue was dried in a hot air dryer at 130°C and crushed using a sieve with an opening diameter of 150 μm to obtain a mixed powder.

[0101] "evaluation" <Particle size> The resulting mixed powder was pulverized using water. Specifically, ball milling was performed using an alumina porcelain grinding pot and partially stabilized zirconia ceramic balls with a diameter of 5 to 20 mm as the medium, and ion-exchanged water was used as the dispersion medium in an amount 1.5 times (by weight) the amount of glass. The particle size of the mixed powder was measured using a laser diffraction / scattering particle size analyzer (MT3300, manufactured by Microtrac-Bell Corporation). Specifically, D10, average particle size (D50), D90, and Dmax were determined. The results are shown in Tables 2 and 3. As for Example 2-26, as mentioned above, the addition of ion-exchanged water caused Glass 1-21 to become a highly viscous cream, making it impossible to pulverize and obtain glass powder. Therefore, for the purpose of comparing properties, ethanol was used instead of ion-exchanged water to pulverize the glass. The particle size results are shown in Table 3, and the values ​​are shown in parentheses. Blank spaces indicate that the measurements were not taken.

[0102] <Thermal characteristics> The resulting mixed powder was filled into a Pt pan and thermal analysis was performed using a thermal analyzer (Shimadzu Corporation, DTG-60). The heating rate was 7°C / min, and measurements were performed from room temperature to 1000°C. The first inflection point in the differential thermal analysis (DTA) curve was designated the glass transition temperature (Tg), the fourth inflection point the softening point (Ts), and the exothermic peak after the softening point the crystallization peak temperature (Tc). When two crystallization peak temperatures (Tc) were observed, the lower one was designated the first crystallization peak temperature (Tc1) and the higher one the second crystallization peak temperature (Tc2). The results are shown in Tables 2 and 3. Blanks indicate that no measurements were performed.

[0103] <Average thermal expansion coefficient> The resulting mixed powder was pressed into a stainless steel mold to produce a powder compact measuring 50 mm in length, 10 mm in height, and 10 mm in width. This compact was then heated and sintered for 15 minutes at the temperatures listed in Tables 2 and 3 to obtain a fired body. The resulting sample was then polished to a diameter of 5 mm and a length of 20 mm. The thermal expansion coefficient was measured using a thermomechanical analyzer (TMA8311, manufactured by Rigaku) ​​to determine the average linear expansion coefficient over the range of 50 to 350°C. The results are shown in Tables 2 and 3. Blank spaces indicate that no measurements were made. The heating rate was 400°C / hour, and the cooling rate was 600°C / hour. To obtain the fired body, alumina, quartz, zirconia, or other materials that are stable at temperatures below 1000°C were used as the base plate, and zirconia powder was applied as a release agent.The powder compact was then placed on top of this and fired.

[0104] <Sinterability> The resulting mixed powder was filled into a 17 mm diameter cemented carbide die and pressed under a pressure of 6 MPa to produce a green compact. This green compact was then heated and sintered for 15 minutes at the temperatures listed in Tables 2 and 3 to obtain a sintered body measuring 13±0.5 mm in diameter and 6.5±0.5 mm in height. The heating rate was 400°C / hour and the cooling rate was 600°C / hour. For Example 2-7, the sample was heated and sintered at 1000°C for 30 minutes, then cooled to 850°C and annealed again at 850°C for 15 minutes. To obtain the fired body, alumina, quartz, zirconia, or other materials that are stable at temperatures below 1000°C were used as the base plate, and zirconia powder was applied as a release agent.The powder compact was then placed on top of this and fired.

[0105] The evaluation criteria for sinterability were as follows: The results are shown in Tables 2 and 3. ⊚: When the surface of the fired product is traced with oil-based black ink, there is no bleeding, and the open pores are recognizable as being zero or very close to zero, which is the most preferable state for obtaining a highly reliable product with no moisture absorption whatsoever. ○: As a result of cross-sectional observation, although there are some open pores, there are no interconnected pores, and the electrical properties can be evaluated as a sintered body, not in a powder state. If the sinterability is insufficient, the relative permittivity becomes too low or the dielectric loss becomes too large, making it impossible to measure for evaluation of the electrical properties. Therefore, if the electrical properties can be evaluated, it can be determined that the sinterability is at a practical level. ×: Powdery, crumbly with low strength, pumice-like with a specific gravity of less than 2, clearly unsintered, with abnormal appearance such as cracks, etc., not sinterable to a practical level.

[0106] Electrical characteristics The sintered body obtained in the above "Sinterability" was evaluated for its relative permittivity and dielectric loss using a dielectric resonator method. The equipment and measurement environment used were those conforming to JIS R 1627 (1996). The results, along with the frequency, are shown in Tables 2 and 3. Note that "-" indicates that the sinterability was poor and measurement was not possible. In addition, in Example 2-26, since the glass could not be crushed in an aqueous system, the glass powder was crushed using ethanol instead of ion-exchanged water for comparison of characteristics. Therefore, the values ​​are shown in parentheses.

[0107] [Table 2]

[0108] [Table 3]

[0109] Example 2-27, Example 2-28 The mixed powder obtained in Example 2-1 was evaluated for sinterability and electrical properties in the same manner as above, except that the sintering temperature of the molded body in the "Evaluation" section "Sinterability" was changed from 850°C to 820°C (Example 2-27) or 870°C (Example 2-28). The results are shown in Table 4.

[0110] [Table 4]

[0111] The above results indicate that the glass according to this embodiment is a novel glass that has good water resistance and can be crushed in an aqueous system. Furthermore, it was found that further optimization of the composition can produce glass-ceramics that also have good sinterability and excellent electrical properties. In the glass according to this embodiment, WO3 acts as a crystal nucleus effective for the precipitation of CaSiO3 during the formation of the fired body, promoting the precipitation of CaSiO3 crystals. As a result, the precipitation of SiO2 is suppressed, the CaO content in the residual glass is relatively low, and it is believed that good electrical properties due to CaSiO3 can be obtained.

Claims

1. The composition in mole percent on an oxide basis is: SiO ２ : More than 10.0% but less than 49.0%, B ２ O ３ :0% over 34.0% or less, WO ３ :0%more than 1%less than Al ２ O ３ :0% or more and 0.5% or less, CaO: 35.0% or more and 60.0% or less, ZnO: 0% or more and 4.0% or less, MgO: 0% or more and 4.0% or less, BaO: 0% or more and 4.0% or less, and A glass satisfying the following: SrO: 0% or more and 4.0% or less.

2. The composition is Li ２ O, Na ２ O and K ２ The glass according to claim 1 , further satisfying a total content of O: 0% or more and 0.15% or less.

3. The glass according to claim 1 , wherein the composition further satisfies CuO: 0% or more and 1.0% or less.

4. The composition is CeO ２ 2. The glass according to claim 1, further satisfying: 0% or more and 1.0% or less.

5. The glass according to claim 1 , wherein the composition further satisfies the following: the total of ZnO, MgO, CaO, SrO, and BaO: more than 41.0% and less than 55.0%.

6. 10. The glass of claim 1, which is substantially lead-free.

7. The glass is powdered and fired in air at 850°C for 15 minutes to obtain a fired body containing CaSiO ３ 10. The glass of claim 1 comprising crystals.

8. The glass was powdered and fired in air at 850°C for 15 minutes to obtain a fired body, which had a powder X-ray diffraction pattern of SiO at 2θ=26.6°±0.5°. ２ The peak intensity derived from X is CaB ２ O ４ The peak intensity derived from Y is CaSiO ３ 2. The glass according to claim 1, wherein Z>X and Z>Y are satisfied, where Z is the peak intensity resulting from

9. A glass powder obtained by pulverizing the glass according to any one of claims 1 to 8.

10. The glass powder according to claim 9 and optionally SiO ２ and an amorphous glass filler mainly composed of The mixed powder has a content of the glass powder of 50% by mass or more and 100% by mass or less based on the total content of the glass powder and the amorphous glass filler.

11. The mixed powder according to claim 10, wherein the crystallization peak temperatures include a first crystallization peak temperature (Tc1) and a second crystallization peak temperature (Tc2) higher than the first crystallization peak temperature (Tc1).

12. The mixed powder according to claim 11, wherein the first crystallization peak temperature (Tc1) is 850°C or less, and the second crystallization peak temperature (Tc2) is higher than 850°C.

13. The mixed powder is fired in air at 850°C for 15 minutes to obtain a fired body having an average linear expansion coefficient of 50 x 10 at 50 to 350°C. －７ ~100 x 10 －７ The mixed powder according to claim 10, wherein the temperature is / °C.

14. The mixed powder according to claim 10, having an average particle size (D50) of 2.0 μm or less.

15. The glass powder according to claim 9 and optionally SiO ２ and a vehicle, The glass paste has a content of the glass powder of 50% by mass or more and 100% by mass or less based on the total content of the glass powder and the amorphous glass filler.

16. The glass powder according to claim 9 and optionally SiO ２ and a resin binder, a content of the glass powder relative to the total of the glass powder and the amorphous glass filler is 50% by mass or more and 100% by mass or less.

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