Glass compositions and sealing materials

Abstract

The present invention provides a glass composition that does not contain environmentally harmful lead and can be sealed by low-temperature firing, as well as a sealing material using the same. The glass composition is characterized by containing, in mole percent, MgO+CaO+SrO+BaO+ZnO (1-30%), TeO2 (30-80%), and MoO3 (5-30%).

Description

Technical Field

[0001] The present invention relates to a glass composition that does not contain harmful lead, has weather resistance, and can be fired at a low temperature to achieve airtight sealing, and a sealing material using the same. Background Art

[0002] Sealing materials are used in semiconductor integrated circuits, crystal oscillators, metal parts, flat panel displays, and glass terminals for LEDs.

[0003] The above-mentioned sealing materials require chemical durability and heat resistance, so glass-based sealing materials are used instead of resin-based adhesives. Sealing materials are also required to have properties such as mechanical strength, fluidity, and weather resistance, but for the sealing of electronic components equipped with heat-sensitive elements, the sealing temperature must be as low as possible. Specifically, sealing below 400°C is preferred. Therefore, as a glass that meets the above-mentioned characteristics, lead borate-based glass containing a large amount of PbO, which has a great effect of lowering the softening point, is widely used (for example, see Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 63-315536

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2019-202921 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] Environmental issues have been identified with the PbO contained in lead borate glass, leading to a desire to replace lead borate glass with glass that does not contain PbO. Consequently, various low-softening-point glasses have been developed as alternatives to lead borate glass. However, generally speaking, as the softening point of glass decreases, its weather resistance tends to deteriorate, and achieving this balance is a technical challenge. The CuO-TeO2-MoO3 glass described in Patent Document 2 is expected to be a candidate for replacing lead borate glass. While it exhibits weather resistance, the heat resistance of the aforementioned components requires a further reduction in the sealing temperature.

[0010] In view of the above, an object of the present invention is to provide a glass composition that has weather resistance and can be sealed by firing at a low temperature, and a sealing material using the same.

[0011] Means used to solve problems

[0012] The glass composition of the present invention is characterized by containing, in mol%, 1-30% of MgO+CaO+SrO+BaO+ZnO, 30-80% of TeO2, and 35-30% of MoO. Here, "MgO+CaO+SrO+BaO+ZnO" refers to the total amount of MgO, CaO, SrO, BaO, and ZnO.

[0013] The glass composition of the present invention achieves weather resistance and a low softening point by setting the total content of MgO, CaO, SrO, BaO, and ZnO to 1% or more. Generally, a low softening point of glass tends to make vitrification difficult or phase separation difficult, making it difficult to obtain homogeneous glass. However, in the present invention, by setting the TeO2 content to 30% or more and the MoO3 content to 5% or more, the glass is stabilized and homogeneous glass can be obtained.

[0014] Furthermore, the glass composition of the present invention preferably contains 1 to 30% of Li2O+Na2O+K2O in terms of mol%. Here, "Li2O+Na2O+K2O" refers to the total amount of Li2O, Na2O, and K2O.

[0015] Furthermore, the glass composition of the present invention preferably contains 1 to 30% BaO in mol%.

[0016] Furthermore, the glass composition of the present invention preferably contains 0 to 10% TiO2 + Al2O3 in mol%. Here, "TiO2 + Al2O3" refers to the total amount of TiO2 and Al2O3.

[0017] Furthermore, the glass composition of the present invention preferably contains Al2O3 in an amount of 1 to 10% by mol%.

[0018] Furthermore, the glass composition of the present invention preferably contains, in mol%, 0 to 30% of CuO, 30 to 20% of WO, and 50 to 10% of P2O.

[0019] Furthermore, the glass composition of the present invention preferably contains CuO in an amount of 1 to 30% by mol%.

[0020] The sealing material of the present invention is characterized by containing 40 to 100% by volume of glass powder comprising the above-mentioned glass composition and 0 to 60% by volume of refractory filler powder.

[0021] In the sealing material of the present invention, the refractory filler powder preferably contains Zr2WO4(PO4)2.

[0022] In the sealing material of the present invention, the refractory filler powder is preferably substantially spherical.

[0023] The sealing material of the present invention is preferably used for packaging of crystal oscillators.

[0024] The sealing material paste of the present invention is characterized by containing the above-mentioned sealing material and a vehicle.

[0025] Effects of the Invention

[0026] The present invention can provide a glass composition that does not contain environmentally harmful lead and can be fired at a low temperature for sealing, and a sealing material using the same. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram showing a measurement curve obtained using a Macro (large) differential thermal analyzer. DETAILED DESCRIPTION

[0028] The glass composition of the present invention contains, in mol%, 1-30% MgO + CaO + SrO + BaO + ZnO, 30-80% TeO2, and 5-30% MoO3. The reasons for limiting the glass composition as described above are explained below. It should be noted that, unless otherwise specified, "%" in the following description of the content of each component refers to "mol%."

[0029] MgO, CaO, SrO, BaO, and ZnO are components that expand the vitrification range and improve the weather resistance of glass. The content of MgO+CaO+SrO+BaO+ZnO is 1-30%, preferably 3-25%, more preferably 5-20%, further preferably 8-18%, and particularly preferably 10-15%. If the content of MgO+CaO+SrO+BaO+ZnO is too low, vitrification becomes difficult. In addition, the weather resistance of the glass deteriorates, and the glass becomes thermally unstable, and the glass is easily devitrified during melting or firing. On the other hand, even if the content of MgO+CaO+SrO+BaO+ZnO is too high, the glass becomes thermally unstable, and the glass is easily devitrified during melting or firing.

[0030] It should be noted that the preferred ranges of the contents of MgO, CaO, SrO, BaO, and ZnO are as follows.

[0031] MgO is a component that expands the glass transition range, suppresses excessive increases in the softening point of glass, and improves the weather resistance of glass. The MgO content is 1 to 30%, preferably 3 to 25%, more preferably 5 to 20%, further preferably 8 to 18%, and particularly preferably 10 to 15%. If the MgO content is too low, vitrification becomes difficult, the weather resistance of the glass deteriorates, and the glass becomes thermally unstable, easily causing devitrification during melting or firing. On the other hand, even if the MgO content is too high, the glass becomes thermally unstable and easily causing devitrification during melting or firing.

[0032] CaO is a component that expands the vitrification range, suppresses excessive increases in the softening point of glass, and improves the weather resistance of glass. The CaO content is 1 to 30%, preferably 3 to 25%, more preferably 5 to 20%, further preferably 8 to 18%, and particularly preferably 10 to 15%. If the CaO content is too low, vitrification becomes difficult, the weather resistance of the glass deteriorates, and the glass becomes thermally unstable, easily causing devitrification during melting or firing. On the other hand, even if the CaO content is too high, the glass becomes thermally unstable, easily causing devitrification during melting or firing.

[0033] SrO is a component that expands the glass transition range, suppresses excessive increases in the softening point of glass, and improves the weather resistance of glass. The SrO content is 1 to 30%, preferably 3 to 25%, more preferably 5 to 20%, further preferably 8 to 18%, and particularly preferably 10 to 15%. If the SrO content is too low, vitrification becomes difficult, the weather resistance of the glass deteriorates, and the glass becomes thermally unstable, easily causing devitrification during melting or firing. On the other hand, even if the SrO content is too high, the glass becomes thermally unstable, easily causing devitrification during melting or firing.

[0034] Compared to MgO, CaO, SrO, and ZnO, BaO is a component that significantly expands the vitrification range, significantly lowers the softening point of glass, and significantly improves the weather resistance of glass. The BaO content is 1 to 30%, preferably 3 to 25%, more preferably 5 to 20%, further preferably 8 to 18%, and particularly preferably 10 to 15%. If the BaO content is too low, vitrification becomes difficult, the softening point does not decrease, and low-temperature sealing becomes difficult. In addition, the glass becomes thermally unstable and easily loses transparency during melting or firing. In addition, it becomes difficult to maintain the weather resistance of the glass. On the other hand, even if the BaO content is too high, the glass becomes thermally unstable and easily loses transparency during melting or firing.

[0035] ZnO is a component that expands the glass transition range, suppresses excessive increases in the softening point of glass, and improves the weather resistance of glass. The ZnO content is 1 to 30%, preferably 3 to 25%, more preferably 5 to 20%, further preferably 8 to 18%, and particularly preferably 10 to 15%. If the ZnO content is too low, vitrification becomes difficult, the weather resistance of the glass deteriorates, and the glass becomes thermally unstable, easily causing devitrification during melting or firing. On the other hand, even if the ZnO content is too high, the glass becomes thermally unstable, easily causing devitrification during melting or firing.

[0036] TeO2 is a component that forms a glass network and improves weather resistance. The content of TeO2 is 30-80%, preferably 35-75%, more preferably 40-70%, further preferably 45-65%, and particularly preferably 50-60%. If the content of TeO2 is too little, the glass becomes thermally unstable, and the glass easily loses transparency when melting or firing, and the weather resistance is easily reduced. On the other hand, if the content of TeO2 is too much, the viscosity (softening point, etc.) of the glass becomes high, low-temperature sealing becomes difficult, and the glass becomes thermally unstable, and the glass easily loses transparency when melting or firing. In addition, the thermal expansion coefficient of the glass tends to become too high.

[0037] MoO3 is a component that forms a glass network and improves weather resistance. The content of MoO3 is 5 to 30%, preferably 7 to 27%, more preferably 10 to 25%, further preferably 12 to 22%, and particularly preferably 15 to 20%. If the content of MoO3 is too little, the glass becomes thermally unstable, and the glass easily loses transparency when melting or when firing, and the viscosity (softening point, etc.) of the glass becomes high, and low-temperature sealing becomes difficult. On the other hand, if the content of MoO3 is too much, it becomes difficult to vitrify. In addition, there is the following tendency: the glass becomes thermally unstable, and the glass easily loses transparency when melting or when firing, and the thermal expansion coefficient of the glass becomes too high.

[0038] The glass composition of the present invention may contain the following components in addition to the above components in the glass composition.

[0039] Li2O, Na2O, and K2O are components that reduce the viscosity of the glass (softening point, etc.). Li2O+Na2O+K2O is preferably 1-30%, more preferably 2-25%, further preferably 5-20%, and particularly preferably 8-15%. If Li2O+Na2O+K2O is too little, the viscosity of the glass (softening point, etc.) becomes high, low-temperature sealing becomes difficult, and the glass becomes thermally unstable, and the glass is easily devitrified during melting or firing. On the other hand, if Li2O+Na2O+K2O is too much, the glass becomes thermally unstable, and the glass is easily devitrified during melting or firing.

[0040] Li2O is a component that significantly reduces the viscosity (softening point, etc.) of glass compared to Na2O and K2O. The Li2O content is preferably 1-30%, more preferably 2-25%, even more preferably 3-20%, and particularly preferably 5-18%. If the Li2O content is too low, the viscosity (softening point, etc.) of the glass increases, making low-temperature sealing difficult. On the other hand, if the Li2O content is too high, the glass becomes thermally unstable and is prone to devitrification during melting or firing.

[0041] Compared to K2O, Na2O is a component that reduces the viscosity (softening point, etc.) of glass. The Na2O content is preferably 1-20%, more preferably 2-15%, further preferably 3-12%, and particularly preferably 5-10%. If the Na2O content is too low, the viscosity (softening point, etc.) of the glass increases, making low-temperature sealing difficult. On the other hand, if the Na2O content is too high, the glass becomes thermally unstable and is prone to devitrification during melting or firing.

[0042] K₂O is a component that reduces the viscosity (softening point, etc.) of glass. The K₂O content is preferably 1-30%, more preferably 2-25%, even more preferably 3-20%, and particularly preferably 5-18%. If the K₂O content is too low, the viscosity (softening point, etc.) of the glass increases, making low-temperature sealing difficult. On the other hand, if the K₂O content is too high, the glass becomes thermally unstable and is prone to devitrification during melting or firing.

[0043] Furthermore, in order to lower the softening point of the glass through the alkali mixing effect, the molar ratio of Li2O / K2O is preferably 0.3 to 5, more preferably 0.4 to 4, 0.5 to 3, even more preferably 0.6 to 2, and particularly preferably 0.7 to 1.5. If the Li2O / K2O ratio is too low, the viscosity of the glass (softening point, etc.) becomes high, making low-temperature sealing difficult, and the glass becomes thermally unstable, easily causing devitrification during melting or firing. On the other hand, if the Li2O / K2O ratio is too high, the glass becomes thermally unstable, easily causing devitrification during melting or firing.

[0044] TiO2 and Al2O3 are components that improve weather resistance. TiO2 + Al2O3 is preferably 0-10%, more preferably 0.1-8%, even more preferably 1-6%, and particularly preferably 2-5%. Excessive amounts of TiO2 + Al2O3 increase the viscosity (softening point, etc.) of the glass, making low-temperature sealing difficult. Furthermore, the glass becomes thermally unstable, making it more susceptible to devitrification during melting or firing.

[0045] It should be noted that the preferred ranges of the contents of TiO2 and Al2O3 are as follows.

[0046] The TiO2 content is preferably 0-8%, more preferably 0.1-6%, further preferably 1-5%, and particularly preferably 2-4%. The Al2O3 content is preferably 0-8%, more preferably 0.1-5%, further preferably 0.5-3%, and particularly preferably 1-2%.

[0047] CuO is a component that reduces the viscosity of glass (softening point, etc.) and reduces the thermal expansion coefficient of glass. In addition, when metal is sealed, it is a component that increases the bonding strength between glass and metal. The details of its mechanism are not yet clear, but it is believed that due to the high diffusivity of Cu atoms, the glass and metal become easily integrated by Cu atoms diffusing from the surface of the metal to the inside. It should be noted that there is no particular restriction on the type of metal used as the sealing object. Examples include iron, iron alloys, nickel, nickel alloys, copper, copper alloys, aluminum, and aluminum alloys. The CuO content is preferably 0-30%, 0-10%, 0.1-5%, 0.5-3%, and particularly 1-2%. In addition, the CuO content when metal is sealed is preferably 1-30%, more preferably 1-20%, further preferably 3-15%, and particularly preferably 5-10%. If the CuO content is too high, the glass becomes thermally unstable. During the sealing process, metallic Cu precipitates from the glass surface, which may have an adverse effect on the sealing and electrical properties. In addition, glass is easily devitrified during melting or firing.

[0048] WO3 is a component that reduces the thermal expansion coefficient of glass. The WO3 content is 0-20%, 0.1-10%, and particularly 1-5%. Excessive WO3 content can cause thermal instability in the glass, making it more susceptible to devitrification during melting or firing. Furthermore, the viscosity (softening point, etc.) of the glass increases, making low-temperature sealing difficult.

[0049] P2O5 is a component that forms a glass network and thermally stabilizes the glass. The P2O5 content is preferably 0-10%, more preferably 0.1-5%, even more preferably 0.2-2%, and particularly preferably 0.5-1%. Excessive P2O5 content increases the viscosity (softening point, etc.) of the glass, making low-temperature sealing difficult and reducing weather resistance.

[0050] Ag2O is a component that reduces the viscosity (softening point, etc.) of glass. The Ag2O content is preferably 0-10%, more preferably 0.1-5%, even more preferably 0.2-3%, and particularly preferably 0.5-2%. Excessive Ag2O content can cause thermal instability in the glass, making it susceptible to devitrification during melting or firing. Furthermore, depending on the firing atmosphere, metallic Ag may precipitate from the glass.

[0051] AgI is a component that reduces the viscosity (softening point, etc.) of glass. The AgI content is preferably 0-10%, more preferably 0.1-5%, even more preferably 0.2-2%, and particularly preferably 0.5-1%. Excessive AgI content tends to increase the thermal expansion coefficient of the glass too much.

[0052] Nb2O5 is a component that thermally stabilizes glass and improves its weather resistance. The Nb2O5 content is preferably 0-10%, more preferably 0.1-5%, even more preferably 0.2-2%, and particularly preferably 0.5-1%. Excessive Nb2O5 content increases the viscosity (softening point, etc.) of the glass, making low-temperature sealing difficult.

[0053] V2O5 is a component that forms a glass network and reduces the viscosity (softening point, etc.) of the glass. The V2O5 content is preferably 0-10%, more preferably 0.1-5%, even more preferably 0.2-3%, and even more preferably 1-2%. Excessive V2O5 content can cause thermal instability in the glass, making it more susceptible to devitrification during melting or firing, and also reducing weather resistance.

[0054] Ga2O3 is a component that thermally stabilizes glass and improves weather resistance, but is very expensive, so its content is preferably less than 0.01%, and particularly preferably not contained.

[0055] SiO2, GeO2, Fe2O3, NiO, CeO2, B2O3, Sb2O3, and ZrO2 are components that stabilize the glass thermally and prevent devitrification. They can be added in amounts of less than 2%. If their content is too high, the glass becomes thermally unstable and is prone to devitrification during melting or firing.

[0056] The glass composition of the present invention preferably contains substantially no PbO for environmental reasons. Here, "substantially no PbO" means that the content of PbO in the glass composition is 1% or less.

[0057] The sealing material of the present invention contains glass powder comprising the above-mentioned glass composition. In order to improve mechanical strength or adjust the thermal expansion coefficient, the sealing material of the present invention may also contain refractory filler powder. The mixing ratio is preferably 40 to 100% by volume of glass powder and 0 to 60% by volume of refractory filler powder, more preferably 50 to 99% by volume of glass powder and 1 to 50% by volume of refractory filler powder, further preferably 60 to 95% by volume of glass powder and 5 to 40% by volume of refractory filler powder, and particularly preferably 70 to 90% by volume of glass powder and 10 to 30% by volume of refractory filler powder. If the content of refractory filler powder is too much, the proportion of glass powder becomes relatively small, and it is difficult to ensure the desired fluidity.

[0058] The refractory filler powder preferably contains Zr 2 WO 4 (PO 4 ) 2. Zr 2 WO 4 (PO 4 ) 2 is unlikely to react with the glass powder and can effectively reduce the thermal expansion coefficient of the sealing material.

[0059] In addition, the sealing material of the present invention can also use refractory filler powders other than Zr2WO4(PO4)2 as refractory filler powders. As other refractory filler powders, NbZr(PO4)3, Zr2MoO4(PO4)2, Hf2WO4(PO4)2, Hf2MoO4(PO4)2, zirconium phosphate, zircon, zirconium oxide, tin oxide, aluminum titanate, quartz, β-spodumene, mullite, titanium dioxide, quartz glass, β-eucryptite, β-quartz, willemite, cordierite, Sr can be used alone or in combination of two or more. 0.5 Powders of Zr2(PO4)3, etc.

[0060] The refractory filler powder is preferably roughly spherical. In this way, when the glass powder softens, the fluidity of the glass powder is less likely to be hindered by the refractory filler powder, and as a result, the fluidity of the sealing material is improved. In addition, a smooth glaze layer is easily obtained. In addition, even if a portion of the refractory filler powder is exposed on the surface of the glaze layer, since the refractory filler powder is roughly spherical, the stress of this portion is dispersed, and further, when sealing, even if the sealed object is abutted against the glaze layer, it is difficult to generate undue stress on the sealed object, and as a result, it is easy to ensure airtightness. It should be noted that the "roughly spherical" mentioned in the present invention is not limited to a true sphere, and refers to a spherical shape in which the value of the shortest diameter passing through the center of gravity of the refractory filler powder divided by the longest diameter is greater than 0.5, preferably greater than 0.7.

[0061] It should be noted that the particle size of the refractory filler powder is preferably an average particle size D 50 The particle size is about 0.2 to 20 μm.

[0062] The softening point of the sealing material of the present invention is preferably below 350°C, particularly preferably below 340°C. If the softening point is too high, the viscosity of the glass becomes high, so the sealing temperature rises to meet the specified fluidity, and the heat during sealing may deteriorate the element. It should be noted that the lower limit of the softening point is not particularly limited, and is actually above 180°C. Here, the "softening point" refers to the average particle size D 50 The softening point measured by the Macro differential thermal analyzer is a value obtained by using a sealing material with a thickness of 0.5 to 20 μm as a test sample. The measurement conditions are as follows: the measurement is started from room temperature and the heating rate is set to 10°C / min. It should be noted that the softening point measured by the Macro differential thermal analyzer is Figure 1 The temperature (Ts) of the fourth inflection point on the measurement curve is shown.

[0063] The thermal expansion coefficient (30-150°C) of the sealing material of the present invention is preferably 20×10 -7 / ℃~200×10 -7 / ℃, more preferably 30×10-7 / ℃~160×10 -7 / ℃, more preferably 40×10 -7 / ℃~140×10 -7 / ℃, particularly preferably 50×10 -7 / ℃~120×10 -7 / ℃. If the thermal expansion coefficient is too low or too high, the sealing part will be easily damaged during or after sealing due to the thermal expansion difference with the sealed material.

[0064] The sealing material of the present invention having the above-mentioned characteristics is particularly suitable for packaging of crystal oscillators requiring sealing at low temperatures.

[0065] Next, an example of a method for producing glass powder using the glass composition of the present invention and a method for using the glass composition of the present invention as a sealing material will be described.

[0066] First, the raw material powder prepared to achieve the above composition is melted at 800-1000°C for 1-2 hours until a homogeneous glass is obtained. Next, the molten glass is formed into a film or the like, and then pulverized and classified to produce a glass powder comprising the glass composition of the present invention. It should be noted that the average particle size D of the glass powder is 50 The preferred diameter is about 1 to 20 μm. If necessary, a sealing material is prepared by adding various refractory filler powders to glass powder.

[0067] Next, a vehicle is added to the glass powder (or sealing material) and kneaded to prepare a glass paste (or sealing material paste). The vehicle is mainly composed of an organic solvent and a resin, and the resin is added to adjust the viscosity of the paste. In addition, a surfactant, thickener, etc. may be added as needed.

[0068] The organic solvent is preferably an organic solvent that has not only a low boiling point (for example, a boiling point of 300°C or less), but also has little residue after firing and does not deteriorate the glass, and its content is preferably 10 to 40% by mass. As the organic solvent, propylene carbonate, toluene, N,N'-dimethylformamide (DMF), 1,3-dimethyl-2-imidazolidinone (DMI), dimethyl carbonate, butyl carbitol acetate (BCA), isoamyl acetate, dimethyl sulfoxide, acetone, methyl ethyl ketone, etc. are preferably used. In addition, as the organic solvent, higher alcohols are further preferably used. Since higher alcohols have viscosity in themselves, they can be made into pastes even without adding resin to the vehicle. In addition, pentanediol and its derivatives, specifically diethyl pentanediol (C9H 20 O2) also has excellent viscosity and can therefore be used as a solvent.

[0069] The resin preferably has a low decomposition temperature, produces little residue after firing, and is less likely to deteriorate the glass. The content of the resin is preferably 0.1 to 20% by mass. Preferred resins include nitrocellulose, polyethylene glycol derivatives, polyethylene carbonate, and acrylates (acrylic resins).

[0070] Next, a glass paste (sealing material paste) is applied to the sealing portion of the sealed object made of metal, ceramic, or glass using a dispenser, screen printer, or other applicator, dried, and glazed at 300-350°C. Thereafter, the paste is brought into contact with the sealed object and heat-treated at 350-400°C to soften and flow the glass powder, thereby sealing the two.

[0071] The glass composition of the present invention can be used for purposes other than sealing, such as coating and filling. It can also be used in forms other than pastes, specifically in the form of powder, green sheet, flat plate (pressed glass frit as a sintered body of powder), etc.

[0072] Example

[0073] The present invention will be described in detail based on examples. Tables 1 and 2 show examples (samples No. 1 to 17) of the present invention and comparative examples (samples No. 18 to 21).

[0074]

Table 1

[0075]

[0076]

Table 2

[0077]

[0078] First, various glass raw materials such as oxides and carbonates were mixed to form the glass compositions shown in the table. After preparing a glass batch, the glass batch was placed in a platinum crucible and melted in air at 800-1000°C for 1-2 hours. The molten glass was then formed into a film using water-cooled rollers, pulverized using a ball mill, and passed through a sieve with a mesh size of 75 μm to obtain a glass powder having an average particle size D50 of approximately 10 μm.

[0079] Then, as shown in the table, the obtained glass powder was mixed with refractory filler powder to obtain a mixed powder.

[0080] As the refractory filler powder, Zr2WO4(PO4)2 (represented as ZWP in the table) and NbZr(PO4)3 (represented as NZP in the table) in a roughly spherical shape were used. 50 About 10μm.

[0081] Samples No. 1 to 21 were evaluated for glass transition temperature, thermal expansion coefficient, softening point, fluidity, presence or absence of devitrification, weather resistance, and adhesion to metal.

[0082] The glass transition temperature and thermal expansion coefficient (30-150°C) were evaluated as follows. A mixed powder sample was placed in a rod-shaped mold and press-molded. The sample was then fired at 380°C for 10 minutes on an alumina substrate coated with a release agent. The fired product was then processed into a desired shape and measured using a TMA apparatus.

[0083] The softening point was measured using a Macro differential thermal analyzer, with the fourth inflection point being the softening point. The measurement atmosphere was air, the heating rate was set at 10° C. / min, and the measurement was started from room temperature.

[0084] Flowability was evaluated as follows. A weight corresponding to the combined density of the mixed powder sample was placed in a 20 mm diameter mold, pressed, and then fired at 380°C for 10 minutes on a glass substrate. A flow diameter of 19 mm or greater was rated "○"; a flow diameter of less than 19 mm was rated "X."

[0085] The presence or absence of devitrification was evaluated as follows: The surface of the fired body produced above was visually observed, and the surface without glass luster was evaluated as "presence" of devitrification, while the surface without glass luster was evaluated as "no devitrification".

[0086] Weather resistance was evaluated using an accelerated degradation test based on the PCT (Pressure Cooker Test). Specifically, the calcined product prepared above was held at 121°C, 2 atmospheres, and a relative humidity of 100% for 24 hours. Visual inspection was then performed, and results indicating no precipitates on the surface of the calcined product were rated as "○"; otherwise, as "×."

[0087] Bonding properties with metal were evaluated as follows. A glass powder sample, weighing a weight corresponding to its density, was placed in a 20 mm diameter mold for press molding. The sample was then fired at 380°C for 10 minutes in a nitrogen atmosphere on a stainless steel (SUS304) substrate. After firing, the surface of the SUS304 substrate opposite the surface encapsulating the fired product was attached to a wall perpendicular to the horizon. If the fired product did not peel from the SUS304 substrate due to its own weight even after 24 hours, a positive rating was given; if it did peel and fall, a negative rating was given.

[0088] As is clear from the table, samples No. 1 to 17, which are examples of the present invention, have low softening points and excellent fluidity. They also have excellent weather resistance. On the other hand, sample No. 18, which is a comparative example, has glass devitrification during firing and poor fluidity due to the excessive amount of MgO+CaO+SrO+BaO+ZnO. Sample No. 19, which is a comparative example, does not vitrify due to the excessive amount of MoO3. Samples No. 20 and 21, which are comparative examples, do not contain MgO, CaO, SrO, BaO, or ZnO, and therefore have poor weather resistance.

[0089] Industrial applicability

[0090] The glass composition of the present invention is suitable for use in semiconductor integrated circuits, crystal oscillators, flat-panel displays, glass terminals for LEDs, and sealing of aluminum nitride substrates. It can also be used as a metal sealing material.

Claims

1. A glass composition, characterized in that: It contains, in mol%, MgO + CaO + SrO + BaO + ZnO 1% to 30%, TeO2 30% to 80%, MoO3 5% to 30%, BaO 1% to 30%, and CuO 4% or less, and the molar ratio of Li2O / K2O is 0.6 to 2.

2.

2. The glass composition according to claim 1, wherein In terms of mol%, it contains Li2O+Na2O+K2O 1% to 30%, MgO+CaO+SrO+BaO+ZnO 1% to 30%, TeO2 30% to 80%, and MoO3 5% to 30%.

3. The glass composition according to claim 1 or 2, characterized in that The content of Li2O is 1% to 30% in mol%.

4. The glass composition according to claim 1 or 2, characterized in that In terms of mol%, it also contains TiO2 + Al2O 30% to 10%.

5. The glass composition according to claim 1 or 2, characterized in that In terms of mol%, it also contains 1% to 10% of Al2O3.

6. The glass composition according to claim 1 or 2, wherein: In terms of mol%, it further contains WO3 0% to 20% and P2O5 0% to 10%.

7. The glass composition according to claim 1 or 2, characterized in that In terms of mol%, it further contains 1% to 4% of CuO.

8. A sealing material, characterized in that: The glass composition according to any one of claims 1 to 7 contains 40% to 100% by volume of glass powder and 0% to 60% by volume of refractory filler powder.

9. The sealing material according to claim 8, characterized in that The refractory filler powder contains Zr2WO4(PO4)2.

10. The sealing material according to claim 8 or 9, characterized in that: The refractory filler powder is approximately spherical.

11. The sealing material according to claim 8 or 9, characterized in that: Used in crystal oscillator packages.

12. A sealing material paste, characterized in that: Contains the sealing material according to any one of claims 8 to 11 and a vehicle.

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