TW201815712A - Bismuth-based glass, method for manufacturing bismuth-based glass, and sealing material - Google Patents

Abstract

This bismuth-based glass contains, as a glass composition, 25-45% of Bi2O3, 20-35% of B2O3, and more than 90% and up to 100% of Bi2O3+B2O3+BaO+ZnO+CuO+MnO+Fe2O3+TiO2+V2O5+Cr2O3+Co3O4+NiO by mol%, in terms of oxides, and is characterized in that the molar ratio of (Bi2O3+B2O3+BaO+ZnO)/(CuO+MnO+Fe2O3+TiO2+V2O5+Cr2O3+Co3O4+NiO) is 2.0-3.5.

Description

Method for producing bismuth glass, bismuth glass and sealing material

The present invention relates to a method for producing a bismuth-based glass, a bismuth-based glass, and a sealing material, and more particularly to a bismuth-based glass or lanthanum system which is preferable for a sealing treatment using laser light (hereinafter, a laser sealing). Glass manufacturing method and sealing material.

In recent years, as a flat panel display panel, an organic electroluminescence (EL) display has attracted attention. Conventionally, as an adhesive material of an organic EL display, an organic resin-based adhesive having low-temperature curability is used. However, since the organic resin-based adhesive does not completely block the intrusion of gas or moisture, the active device or the organic light-emitting layer having low water resistance is likely to be deteriorated, and the display characteristics of the organic EL display deteriorate with time.

On the other hand, the sealing material containing the glass powder is more difficult to permeate the gas or the moisture than the organic resin-based adhesive, and therefore the airtightness inside the organic EL display can be ensured.

However, since the softening temperature of the glass powder is higher than that of the organic resin-based adhesive, there is a possibility that the active element or the organic light-emitting layer is thermally deteriorated at the time of sealing. According to this situation, the laser seal is attracting attention. According to the laser seal, it is possible to locally heat only the portion to be sealed, and it is possible to seal the sealed object such as the alkali-free glass substrate without thermally degrading the active device or the organic light-emitting layer.

Further, in recent years, research has been conducted to realize the maintenance of characteristics or the long life of hermetic seals. For example, regarding a hermetic package in which a light-emitting diode (LED) element is packaged, from the viewpoint of thermal conductivity, aluminum nitride, a low-temperature calcined substrate having a thermal via (low temperature) is used. A low temperature Co-fired Ceramic (LTCC) is used as the substrate. In this case, it is also preferred to perform laser sealing on the substrate and the lid. In particular, with respect to a hermetic package in which an LED element that emits light in an ultraviolet wavelength region is packaged, it is easy to maintain the light-emitting characteristics in the ultraviolet wavelength region by laser sealing. Further, thermal deterioration of the LED element can be prevented by the laser sealing.

Further, in a hermetic package in which a microelectromechanical system (MEMS) device is packaged, a laser seal is preferably used in order to prevent deterioration of characteristics of the MEMS element. [Prior Art Document] [Patent Literature]

[Patent Document 1] US Patent No. 6416375 (Patent Document 2) Japanese Patent Laid-Open No. 2006-315902

[Problems to be Solved by the Invention] The sealing material used in the laser sealing usually contains glass powder, refractory filler powder, and a laser absorbing material. The glass powder is a component which softens the flow during laser sealing and reacts with the sealed object to secure the sealing strength. The refractory filler powder is a material that acts to reduce the coefficient of thermal expansion by acting as an aggregate, and does not soften the flow during laser sealing. The laser absorbing material is a material for absorbing laser light and converting it into thermal energy during laser sealing, and does not soften the flow during laser sealing.

As the glass powder, lead borate glass has been used in the past, but from the viewpoint of the environment, lead-free glass has been used in recent years. In particular, the bismuth-based glass has a low melting point and is excellent in softening fluidity, and therefore is favored as a lead-free glass. However, the main component Bi ₂ O _{3 of the} lanthanide glass hardly has a laser absorbing ability, and thus the laser absorbing ability is likely to be insufficient. Therefore, in order to compensate for the laser absorption ability of the lanthanide glass, it is necessary to increase the content of the laser absorbing material. However, when the content of the laser absorbing material is increased, the laser absorbing material is incorporated into the lanthanum glass at the time of laser sealing, whereby deuteration of the lanthanide glass does not ensure the desired softening fluidity. Further, in order to secure the softening fluidity, if the refractory filler powder is reduced, the thermal expansion coefficient of the sealing material is undesirably increased, and cracks are generated in the sealing material or the sealing material layer during the laser sealing, and airtightness is likely to occur. bad.

Therefore, the present invention has been made in view of the above circumstances, and a technical object thereof is to provide a bismuth-based glass which can achieve both softening fluidity and laser absorbing ability at a high level, and a sealing material using the same. [Means for solving the problem]

As a result of intensive studies, the inventors of the present invention have found that the technical problem can be solved by strictly controlling the ratio of the non-colored component to the colored component in the lanthanide glass, and the present invention has been proposed. In other words, the bismuth-based glass of the present invention contains 25% to 45% of Bi ₂ O ₃ and 20% to 35% of B ₂ O ₃ and 90% to 100% by mol% of the following oxides. % (wherein, not including 90%) of Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO + CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ +NiO as a glass composition, Mo Er ratio (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ +Co ₃ O ₄ +NiO) is 2.0 to 3.5. Here, "Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO + CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO" means Bi _{The total content of 2} O ₃ , B ₂ O ₃ , BaO, ZnO, CuO, MnO, Fe ₂ O ₃ , TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Co ₃ O ₄ and NiO. "(Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO)" means The total content of Bi ₂ O ₃ , B ₂ O ₃ , BaO and ZnO is divided by the total content of CuO, MnO, Fe ₂ O ₃ , TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Co ₃ O ₄ and NiO. Value.

The bismuth-based glass of the present invention closely controls the ratio of the non-colored component to the colored component. Specifically, the lanthanide glass of the present invention has a molar ratio (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ +Co ₃ O ₄ +NiO) is controlled to be 2.0 to 3.5. Mohr ratio (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO) If it is too small, it is unstable to heat, and the glass is easily devitrified when it is sealed by a laser. On the other hand, if Mohr ratio (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O _{When 4} + NiO) is too large, the laser absorption capacity is easily lowered. As a result, if the laser absorbing material is not excessively added to the sealing material or the laser output is not increased, it is difficult to perform laser sealing. Further, the coefficient of thermal expansion is undesirably high, and cracks are generated in the sealant or the sealant layer at the time of laser sealing, and airtightness is likely to occur.

Second, the bismuth-based glass of the present invention preferably has a ZnO content of from 1 mol% to 20 mol%.

Third, the lanthanide glass of the present invention preferably has a MnO content of from 3 mol% to 25 mol%.

Fourth, the lanthanide glass of the present invention preferably does not substantially contain PbO. Here, "substantially does not contain PbO" means that the content of PbO in the glass composition is less than 0.1% by mass.

Fifth, the method for producing the bismuth-based glass of the present invention is a method for producing the bismuth-based glass, and preferably a glass containing any one of a nitrate raw material, a sulfate raw material, a dioxide raw material, and a peroxide raw material. The masterbatch is melt-molded to produce a bismuth-based glass.

Sixth, in the method for producing a bismuth-based glass of the present invention, it is preferred that the dioxide raw material is a manganese dioxide raw material.

Seventh, in the method for producing a bismuth-based glass of the present invention, it is preferred that the peroxide raw material is a permanganate raw material.

Eighth, the sealing material of the present invention is preferably contained in a sealing material comprising a glass powder containing lanthanum glass and a refractory filler powder, the content of the glass powder being 50% by volume to 95% by volume, and the content of the refractory filler powder being 1% by volume to 40% by volume, and the lanthanide glass is the lanthanum glass.

Ninth, the sealing material of the present invention is preferably that the refractory filler powder is selected from cordierite, willemite, alumina, zirconium phosphate compound, zircon, zirconium oxide, One or more of tin oxide, quartz glass, β-eucryptite, and spodumene.

Tenth, the sealing material of the present invention preferably has a content of the laser absorbing material of 5% by volume or less.

Eleventh, the sealing material of the present invention is preferably used in a laser seal. Thus, thermal deterioration of the element can be prevented at the time of sealing. Further, the light source of the laser light used in the laser sealing is not particularly limited. For example, in terms of ease of handling, a semiconductor laser, a yttrium aluminum garnet (YAG) laser, and a CO _{2 are} preferable. Laser, excimer laser, infrared laser, etc. Further, in order for the sealing material to reliably absorb the laser light, the center wavelength of the laser light is preferably from 500 nm to 1600 nm, particularly preferably from 750 nm to 1300 nm.

As described above, the bismuth-based glass of the present invention contains 25% to 45% of Bi ₂ O ₃ , 20% to 35% of B ₂ O ₃ , and 90% to 100% by mol% of the following oxides. Among them, not including 90%, Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO + CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO as a glass composition, Mo Er ratio (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO) is 2.0 to 3.5. The reason why the glass composition range of the lanthanide glass is defined as described above is shown below. Further, in the description of the glass composition, the expression of % means Mo%.

The content of Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO + CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO is more than 90%, preferably It is 93% or more, 95% or more, 97% or more, and particularly preferably 98% or more. If the content of Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO + CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO is too small, it is difficult to balance Soften fluidity and laser absorption capacity. As a result, if the laser absorbing material is not excessively added to the sealing material or the laser output is not increased, it is difficult to perform laser sealing.

The content of CuO+MnO+Fe ₂ O ₃ +TiO ₂ +V ₂ O ₅ +Cr ₂ O ₃ +Co ₃ O ₄ +NiO is preferably 22% to 33%, more preferably 25% to 30%. When the content of CuO+MnO+Fe ₂ O ₃ +TiO ₂ +V ₂ O ₅ +Cr ₂ O ₃ +Co ₃ O ₄ +NiO is too small, the laser absorption ability is liable to lower. As a result, if the laser absorbing material is not excessively added to the sealing material or the laser output is not increased, it is difficult to perform laser sealing. On the other hand, if the content of CuO+MnO+Fe ₂ O ₃ +TiO ₂ +V ₂ O ₅ +Cr ₂ O ₃ +Co ₃ O ₄ +NiO is too large, it is unstable to heat, so that the glass is sealed at the time of laser sealing. Easy to devitrify.

Mo Er ratio (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO) 2.0 to 3.5, preferably 2.1 to 3.2, more preferably 2.2 to 3.1, particularly preferably 2.4 to 3.0. Mohr ratio (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO) If it is too small, it is unstable to heat, so that the glass is easily devitrified when it is sealed by a laser. On the other hand, if Mohr ratio (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O _{When 4} + NiO) is too large, the laser absorption capacity is easily lowered. As a result, if the laser absorbing material is not excessively added to the sealing material or the laser output is not increased, it is difficult to perform laser sealing. Further, the coefficient of thermal expansion is undesirably high, and cracks are generated in the sealant or the sealant layer at the time of laser sealing, and airtightness is likely to occur.

Bi ₂ O ₃ is a main component of the bismuth-based glass and is a component that improves softening fluidity. The content of Bi ₂ O ₃ is 25% to 45%, preferably 30% to 42%, and more preferably 35% to 40%. When the content of Bi ₂ O ₃ is too small, the softening point becomes too high, and even if laser light is irradiated, it is difficult for the glass to soften and flow. On the other hand, when the content of Bi ₂ O ₃ is too large, the coefficient of thermal expansion is undesirably high, and cracks are generated in the sealant or the sealant layer during laser sealing, and airtightness is likely to occur. In addition, it is unstable to heat, so that the glass is easily devitrified during laser sealing.

B ₂ O ₃ is a component that forms a glass network. The content of B ₂ O ₃ is from 20% to 35%, preferably from 22% to 32%, and more preferably from 24% to 30%. If the content of B ₂ O ₃ is too small, the glass is unstable to heat, so that the glass is easily devitrified during laser sealing. On the other hand, when the content of B ₂ O ₃ is too large, the softening point becomes too high, and even if laser light is irradiated, it is difficult for the glass to soften and flow.

BaO is a component which lowers a softening point, and is a component which improves thermal stability. However, if the content of BaO is too large, it is difficult to lower the coefficient of thermal expansion. As a result, cracks and the like are likely to occur in the sealing material layer. Therefore, the content of BaO is preferably 0% to 15%, 0% to 8%, 0% to 5%, particularly preferably 0.1% to less than 2%.

ZnO is a component that lowers the coefficient of thermal expansion. The content of ZnO is preferably from 0% to 25%, more preferably from 1% to 20%, still more preferably from 5% to 15%. When the content of ZnO is too small, the coefficient of thermal expansion tends to be high. On the other hand, when the content of ZnO is too large, when the content of Bi ₂ O ₃ is 35% or more, the glass is unstable to heat, and the glass is easily devitrified during laser sealing.

CuO and MnO are components which greatly improve the laser absorption ability. The total content of CuO and MnO is preferably from 15% to 35%, more preferably from 20% to 40%, still more preferably from 25% to 30%. When the total content of CuO and MnO is too small, the laser absorption ability is liable to lower. On the other hand, when the total content of CuO and MnO is too large, the softening point becomes too high, and even if the laser beam is irradiated, it is difficult for the glass to soften and flow. In addition, the glass is unstable to heat, so that the glass is easily devitrified during laser sealing. Further, the content of CuO is preferably from 5% to 30%, more preferably from 8% to 30%, still more preferably from 13% to 25%. The content of MnO is preferably from 0% to 20%, more preferably from 3% to 25%, still more preferably from 5% to 15%.

The introduction material of MnO such as MnO ₂ has an oxidation effect upon melting. Further, in the bismuth-based glass, CuO and MnO are used in combination, and the molar ratio CuO/MnO is controlled to 0.5 to 6.2, and Cu ₂ O present in the glass during oxidation is oxidized by introduction of MnO, and the oxidation number is 2 The above copper oxide is increased, whereby the laser absorption ability in the near-infrared wavelength region can be greatly improved. The molar ratio CuO/MnO is preferably from 0.5 to 6.2, more preferably from 0.7 to 6.0, still more preferably from 1.0 to 3.5. If the molar ratio is too small for CuO/MnO, the glass is unstable to heat, so that the glass is easily devitrified during laser sealing. On the other hand, if the molar ratio CuO/MnO is too large, Cu ₂ O is not sufficiently oxidized at the time of melting, and it is difficult to obtain a desired laser absorbing ability.

Fe ₂ O ₃ is a component which improves the laser absorption ability, and when the content of Bi ₂ O ₃ is 35% or more, it is a component which suppresses devitrification at the time of laser sealing. The content of Fe ₂ O ₃ is preferably 0% to 5%, 0.1% to 3%, particularly preferably 0.2% to 2%. If the content of Fe ₂ O ₃ is too large, the balance of the components in the glass composition is impaired, and the glass is easily devitrified.

TiO ₂ , V ₂ O ₅ , Cr ₂ O ₃ , Co ₂ O ₃ and NiO are components for improving the laser absorption ability. The content of each component is preferably from 0% to 7%, from 0.1% to 4%, particularly preferably from 0.5% to less than 2%. If the content of each component is too large, the glass is easily devitrified during laser sealing.

In addition to the above components, for example, the following components may be added.

Al ₂ O ₃ is a component that improves water resistance. The content thereof is preferably from 0% to 5%, from 0% to 3%, particularly preferably from 0.1% to 2%. When the content of Al ₂ O ₃ is too large, the softening point becomes too high, and even if laser light is irradiated, it is difficult for the glass to soften and flow.

MgO, CaO, and SrO are components that improve thermal stability. However, when the content of MgO, CaO, and SrO is too large, it is difficult to ensure the softening fluidity and the thermal expansion coefficient. Therefore, the total content and individual content of MgO, CaO, and SrO are preferably 0% to 7%, 0% to 5%, 0% to 3%, 0% to less than 2%, and 0% to 1%, particularly preferably 0% to less than 1%.

SiO ₂ is a component that improves water resistance. The content thereof is preferably from 0% to 8%, from 0% to 5%, particularly preferably from 0% to less than 1%. When the content of SiO ₂ is too large, the softening point becomes too high, and even if laser light is irradiated, it is difficult for the glass to soften and flow.

Li ₂ O, Na ₂ O, K ₂ O, and Cs ₂ O are components which lower the softening point, but have a function of promoting devitrification upon melting. Therefore, the content of these components is preferably 2% or less, and particularly preferably less than 1%, based on the total content.

P ₂ O ₅ is a component which suppresses devitrification at the time of melting. However, when the amount of addition is too large, phase separation of the glass is likely to occur at the time of melting. Therefore, the content of P ₂ O ₅ is preferably from 0% to 5%, particularly preferably from 0% to less than 1%.

La ₂ O ₃ , Y ₂ O ₃ and Gd ₂ O ₃ are components which suppress phase separation at the time of melting. However, when the content of La ₂ O ₃ , Y ₂ O ₃ and Gd ₂ O ₃ is too large, the softening point becomes excessive. High, even if it is irradiated with laser light, it is difficult to soften the glass. Therefore, the content of La ₂ O ₃ , Y ₂ O ₃ and Gd ₂ O ₃ is preferably 0% to 5%, particularly preferably 0% to less than 1%.

MoO ₃ and CeO ₂ are components that improve the absorption capacity of the laser. The content of each component is preferably from 0% to 7%, from 0% to 4%, particularly preferably from 0% to less than 1%. If the content of each component is too large, the glass is easily devitrified during laser sealing.

From the viewpoint of the environment, it is preferred that the PbO is not substantially contained.

The sealing material of the present invention is preferably contained in a sealing material comprising a glass powder containing lanthanum glass and a refractory filler powder, the content of the glass powder being 50% by volume to 95% by volume, and the content of the refractory filler powder being 1% by volume. ～40% by volume, and the lanthanide glass is the lanthanide glass.

In the sealing material of the present invention, the content of the glass powder is preferably from 50% by volume to 95% by volume, from 60% by volume to 80% by volume, particularly preferably from 65% by volume to 75% by volume. When the content of the glass powder is small, the softening fluidity of the sealing material is liable to lower. On the other hand, when the content of the glass powder is large, the content of the refractory filler powder is relatively small, and the thermal expansion coefficient of the sealing material is undesirably increased.

The maximum particle diameter D _{max of the} glass powder is preferably 10 μm or less, and particularly preferably 5 μm or less. When the maximum particle diameter D _{max of} the glass powder is too large, the time required for the laser sealing becomes long, and it is difficult to make the gap between the objects to be sealed uniform, and the precision of the laser sealing is easily lowered. Here, the "maximum particle diameter D _max " is a value measured by a laser diffraction device, and is expressed in a volume-based cumulative particle size distribution curve measured by a laser diffraction method, and the cumulative amount starts from a small particle. Accumulated to be 99% of the particle size.

The softening point of the glass powder is preferably 480 ° C or lower and 450 ° C or lower, and particularly preferably 350 ° C to 430 ° C. When the softening point of the glass powder is too high, the glass hardly softens during laser sealing. Therefore, if the output of the laser light cannot be increased, the sealing strength cannot be improved. Here, the "softening point" refers to the temperature of the fourth inflection point when measured by a macro-type differential thermal analyzer.

The glass powder can be produced, for example, by preparing a glass batch prepared by mixing various raw materials, adding it to the platinum melt, and melting at 900 ° C to 1200 ° C for 1 hour to 3 hours, and then melting the glass. The mixture was poured out between water-cooled twin rolls and formed into a film shape, and the obtained glass film was pulverized by a ball mill and classified by air classification or the like.

In a part of the raw materials used for the production of the bismuth-based glass, one or two or more kinds of a nitrate raw material, a sulfate raw material, a dioxide raw material, and a peroxide raw material are preferably used. In particular, as the raw material for the introduction of Bi ₂ O ₃ , a nitrate raw material is preferably used, and as the raw material of the dioxide, a manganese dioxide raw material is preferably used, and as the peroxide raw material, a permanganate raw material is preferably used. . Among the coloring components, when the oxidation number is high, there is a component (especially CuO) having an improved laser absorption ability. Further, when such a raw material is used, the oxidation number of the colored component in the molten glass can be increased.

In the sealing material of the present invention, the content of the refractory filler powder is preferably from 1% by volume to 40% by volume, from 10% by volume to 45% by volume, from 20% by volume to 40% by volume, particularly preferably from 22% by volume to 35% by volume. %. When the content of the refractory filler powder is small, the thermal expansion coefficient of the sealing material is undesirably high. On the other hand, when the content of the refractory filler powder is large, the content of the glass powder is relatively small, and the softening fluidity of the sealing material is liable to lower.

As the refractory filler powder, various materials can be used, among which, it is preferably selected from the group consisting of cordierite, strontium zinc ore, alumina, zirconium phosphate-based compound, zircon, zirconia, tin oxide, quartz glass, and β-eucryptite. One or more of spodumene. These refractory filler powders have high mechanical strength in addition to a low coefficient of thermal expansion, and have good compatibility with the bismuth-based glass of the present invention. Further, since β-eucryptite has a high effect of lowering the thermal expansion coefficient of the sealing material, it is particularly preferable.

The maximum particle diameter D _{max of the} refractory filler powder is preferably 15 μm or less, less than 10 μm, less than 5 μm, and particularly preferably 0.5 μm to less than 3 μm. When the maximum particle diameter D _{max of} the refractory filler powder is too large, it is difficult to make the gap between the objects to be sealed uniform, and it is difficult to narrow the gap between the objects to be sealed, and it is difficult to reduce the thickness of the organic EL display or the hermetic package. . Further, when the gap between the objects to be sealed is large, if the difference in thermal expansion coefficient between the sealed object and the sealing material layer is large, cracks and the like are likely to occur in the sealed object and the sealing material layer.

In the sealing material of the present invention, the content of the laser absorbing material is preferably from 0% by volume to 5% by volume, from 0% by volume to 3% by volume, from 0% by volume to 1% by volume, particularly preferably from 0% by volume to 0.1% by volume. %. If the content of the laser absorbing material is too large, the laser absorbing material is incorporated into the glass during laser sealing, whereby the glass is devitrified, and the softening fluidity of the sealing material is liable to lower. Further, the content of the refractory filler powder is relatively small, and the thermal expansion coefficient is not properly increased.

In the sealing material of the present invention, the light absorption rate in the monochromatic light having a wavelength of 808 nm is preferably 75% or more, and more preferably 80% or more. When the light absorptivity is low, the sealing material layer cannot absorb light properly at the time of laser sealing, and if the output of the laser light cannot be increased, the sealing strength cannot be improved. Further, when the output of the laser light is increased, there is a possibility that the element is thermally deteriorated during the laser sealing. Here, the "light absorptivity in monochromatic light having a wavelength of 808 nm" corresponds to a value obtained by measuring the reflectance of monochromatic light of λ = 808 nm by a spectrophotometer for a sealing material layer having a thickness of 5 μm. And the transmittance and the value obtained by subtracting the total value of these from 100%.

In the sealing material of the present invention, the coefficient of thermal expansion is preferably 75 × 10 ^-7 / ° C or less, particularly preferably 50 × 10 ^-7 / ° C or more and 71 × 10 ^-7 / ° C or less. As described above, when the object to be sealed is low in expansion, the stress remaining in the sealed object or the sealing material layer is small, so that it is difficult to cause cracks in the sealed object or the sealing material layer. Here, the "thermal expansion coefficient" means a value measured by a pusher type thermal expansion coefficient measurement (thermomechanical analysis (TMA)), and the measurement temperature range is 30 to 300 °C.

In the sealing material of the present invention, the softening point is preferably 510 ° C or lower, 480 ° C or lower, and particularly preferably 350 ° C to 450 ° C. When the softening point of the sealing material is too high, it is difficult for the sealing material layer to soften and flow during the laser sealing. Therefore, if the output of the laser light cannot be increased, the sealing strength cannot be improved.

The sealing material of the present invention can be used in the form of a powder. However, if it is uniformly kneaded with a vehicle and processed into a sealing material paste, it is easy to handle. The vehicle is mainly composed of a solvent and a resin. The resin is added for the purpose of adjusting the viscosity of the sealing material paste. Further, a surfactant, a tackifier, or the like may be added as needed. The sealing material paste is applied to a sealed object by a coater such as a dispenser or a screen printing machine, and then supplied to a binder.

As the resin, acrylate (acrylic resin), ethyl cellulose, polyethylene glycol derivative, nitrocellulose, polymethylstyrene, polyethylene carbonate, methacrylate or the like can be used. In particular, acrylate and nitrocellulose are preferred because they have good thermal decomposition properties.

As the solvent, N,N'-dimethylformamide (DMF), α-terpineol, higher alcohol, γ-butyrolactone (γ-BL), tetrahydronaphthalene ( Tetralin), butyl carbitol acetate, ethyl acetate, isoamyl acetate, diethylene glycol monoethyl ether, diethylene glycol monoethyl ether acetate, benzyl alcohol, toluene, 3-methoxy- 3-methylbutanol, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, carbonic acid Ester, Dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone, and the like. [Examples]

The present invention will be described in detail based on the embodiments. Furthermore, the following examples are merely illustrative. The invention is not limited by the following examples.

Tables 1 and 2 show examples (samples No. 1 to No. 6) and comparative examples (sample No. 7 to No. 10) of the present invention.

[Table 1]

The glass powder described in the table was produced as follows. First, a glass master batch prepared by mixing various raw materials was prepared so as to have a glass composition in the table, which was added to a platinum crucible and melted at 1000 ° C for 1 hour. At the time of melting, stirring was performed using a platinum rod, and homogenization of the molten glass was performed. Furthermore, regarding the sample No.3 ~ No.5, introduced by raw material nitrate Bi ₂ O ₃ content is 1 percent. Next, a part of the obtained molten glass was discharged between water-cooled twin rolls and formed into a film shape, and the remaining molten glass was discharged into a carbon mold frame and formed into a rod shape. Finally, the obtained glass film was pulverized by a ball mill, and classified by an air classifier so that the average particle diameter D ₅₀ became 1.0 μm and the maximum particle diameter D _{max was} 4.0 μm. In addition, the rod-shaped glass was placed in an electric furnace maintained at a temperature higher than the cold spot by about 20 ° C, and then cooled to a normal temperature at a cooling rate of 3 minutes/min.

The refractory filler powder uses β-eucryptite. The refractory filler powder was adjusted to have an average particle diameter D ₅₀ of 1.0 μm and a maximum particle diameter D _max of 3.0 μm by air classification.

The glass powder and the refractory filler powder were mixed at the mixing ratio shown in the table to prepare samples No. 1 to No. 10. The sample Nos. 1 to 10 were evaluated for thermal expansion coefficient, light absorptivity, softening fluidity, sealing strength, and airtightness. In addition, the "component A" in the table indicates the total content of Bi ₂ O ₃ , B ₂ O ₃ , BaO, and ZnO, and the "component B" indicates CuO, MnO, Fe ₂ O ₃ , TiO ₂ , V ₂ O ₅ , The total content of Cr ₂ O ₃ , Co ₃ O ₄ and NiO, "N/A" indicates that it cannot be evaluated.

The coefficient of thermal expansion is a value measured by a TMA apparatus in a temperature range of 30 ° C to 300 ° C. In addition, as a measurement sample of TMA, it is used for the case where each sample is densely sintered and processed into a predetermined shape.

The light absorption rate was measured as follows. First, each sample and the vehicle liquid (tripropylene glycol monobutyl ether containing ethyl cellulose resin) were uniformly kneaded by three roll mills, and after gelatinization, on an alkali-free glass substrate (Nippon Electric Glass Co., Ltd. limited) The company's OA-10, 40 mm × 40 mm × 0.5 mm thick) was coated on a 30 mm × 30 mm square and dried in a drying oven at 120 ° C for 10 minutes. Next, the temperature was raised from room temperature at 10 ° C /min, and calcination was carried out at 510 ° C for 10 minutes, and then cooled to room temperature at 10 ° C / min and fixed on a glass substrate. Then, with respect to the obtained calcined film having a film thickness of 5 μm, the reflectance and transmittance of the monochromatic light having a wavelength of λ = 808 nm were measured by a spectrophotometer, and the total value of these was subtracted from 100%. The value is taken as the light absorption rate.

The softening fluidity was evaluated by the following method: for each sample, a powder having a mass equivalent to 0.6 cm ^{3 was} dry-pressed into a button shape having an outer diameter of 20 mm by a mold, and placed on a 25 mm × On a 25 mm × 0.6 mm thick alumina substrate, the temperature was raised at 10 ° C / min in air, and then kept at 510 ° C for 10 minutes, then cooled to room temperature at 10 ° C / min, and the diameter of the obtained button was obtained. The measurement was carried out. Specifically, the case where the flow diameter is 16.0 mm or more is evaluated as "○", and the case where the flow diameter is less than 16.0 mm is evaluated as "X".

The seal strength was evaluated as follows. Initially, each sample and the vehicle liquid (tripropylene glycol monobutyl ether containing ethyl cellulose resin) were uniformly kneaded by three roll mills, and after gelatinization, on an alkali-free glass substrate (Nippon Electric Glass Co., Ltd. limited) The company's OA-10, □40 mm × 0.5 mm thick, thermal expansion coefficient 38 × 10 ^-7 / ° C), coated along the edge of the alkali-free glass substrate as a frame (5 μm thick, 0.6 mm wide), Drying was carried out at 120 ° C for 10 minutes using a drying oven. Next, the temperature was raised from room temperature at 10 ° C /min, and calcination was carried out at 510 ° C for 10 minutes, and then the temperature was lowered to room temperature at 10 ° C / min to carry out ashing of the resin component in the paste (debonding treatment) and solidification of the sealing material. Thereby, a sealing material layer is formed on the alkali-free glass substrate. Next, after the other alkali-free glass substrate (□40 mm×0.5 mm thick) which does not form the sealing material layer is accurately overlapped on the alkali-free glass substrate having the sealing material layer, the alkali-free glass substrate having the sealing material layer The side edge sealing material layer irradiates laser light having a wavelength of 808 nm, thereby softening and flowing the sealing material layer, thereby hermetically sealing the alkali-free glass substrates to each other. Further, the irradiation conditions (output, irradiation speed) of the laser light are adjusted in accordance with the average thickness of the sealing material layer. Finally, after the obtained sealing structure was dropped from the upper side to the concrete, the sealing strength was evaluated, and the interface between the alkali-free glass and the sealing material layer was not peeled off and evaluated as "○", and the alkali-free glass and The peeling of the interface of the sealing material layer was evaluated as "△", and the peeling of the interface between the alkali-free glass and the sealing material layer was evaluated as "X".

The airtightness was evaluated as follows. The sealed structure obtained by the above method was kept in a constant temperature and humidity chamber maintained at 121 ° C, humidity of 100%, and 2 atmospheres for 24 hours. Then, the sealing structure was observed with an optical microscope, and the airtightness was evaluated. The indentation of the sealing material layer was not deteriorated, and the intrusion of the water in the sealed structure was evaluated as "○", and the sealing structure was not confirmed. The intrusion of moisture, but the deterioration of the sealing material layer was evaluated as "△", and the intruder who confirmed the moisture in the sealed structure was evaluated as "x".

According to Table 1, the glass compositions of the sample Nos. 1 to 6 were controlled to have a predetermined range. Therefore, the evaluation of the thermal expansion coefficient, the light absorptivity, the softening fluidity, the sealing strength, and the airtightness was good. On the other hand, the molar ratio of sample No. 7 (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O _{Since 3} + Co ₃ O ₄ + NiO) is small, devitrification occurs during calcination and laser sealing, and the evaluation of softening fluidity due to the devitrification is poor, and the evaluation of sealing strength and airtightness cannot be performed. Mohr ratio of sample No. 8 (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ Since O ₄ + NiO) is large, the light absorptivity is low, and the evaluation of sealing strength and airtightness is not good. Sample No. 9 of Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO + CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO When the amount is small, the light absorptivity is low, and the evaluation of fluidity, adhesion strength, and airtightness is poor. Mohr ratio of sample No. 10 (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ Since O ₄ + NiO) is large, the light absorptivity is low, and the evaluation of sealing strength and airtightness is not good. Further, the molar ratio of sample No. 8 (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ +Co ₃ O ₄ +NiO) is too large, so the coefficient of thermal expansion is slightly higher.

For reference, in sample No. 3, the amount of 7.5 vol% of the refractory filler powder was replaced with a laser absorbing material (Fe ₂ O ₃ -Cr ₂ O ₃ -MnO composite oxide, and the average particle diameter D ₅₀ was 1.0). Μm, the maximum particle diameter D _max was 3.0 μm), and the coefficient of thermal expansion rose to 77 × 10 ^-7 / ° C. [Industrial availability]

The bismuth-based glass of the present invention and a sealing material using the same are preferable for laser sealing of an organic EL device such as an organic EL display or an organic EL illuminating device, and in addition to the dye-sensitized solar cell and copper indium gallium selenide. (Copper Indium Gallium Selenide, CIGS) is also preferred for laser sealing of solar cells such as thin film compound solar cells, laser sealing of gas seals such as MEMS packages and LED packages.

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Claims (11)

An bismuth-based glass containing 25% to 45% of Bi ₂ O ₃ and 20% to 35% of B ₂ O ₃ and 90% to 100% by mol% of the following oxides ( Among them, not including 90%, Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO + CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO as a glass composition, Mo Er ratio (Bi ₂ O ₃ + B ₂ O ₃ + BaO + ZnO) / (CuO + MnO + Fe ₂ O ₃ + TiO ₂ + V ₂ O ₅ + Cr ₂ O ₃ + Co ₃ O ₄ + NiO) is 2.0 to 3.5. The bismuth-based glass according to claim 1, wherein the content of ZnO is from 1 mol% to 20 mol%. The bismuth-based glass according to claim 1 or 2, wherein the content of MnO is from 3 mol% to 25 mol%. The bismuth-based glass according to any one of claims 1 to 3, which does not substantially contain PbO. A method for producing a bismuth-based glass according to any one of claims 1 to 4, characterized in that it comprises a nitrate raw material, a sulfate raw material, and a second A glass master batch of any one of an oxide raw material and a peroxide raw material is melt-molded to produce a bismuth-based glass. The method for producing a bismuth-based glass according to claim 5, wherein the dioxide raw material is a manganese dioxide raw material. The method for producing a bismuth-based glass according to claim 5, wherein the peroxide raw material is a permanganate raw material. A sealing material characterized in that, in a sealing material comprising a glass powder comprising a lanthanum glass and a refractory filler powder, the content of the glass powder is 50% by volume to 95% by volume, and the content of the refractory filler powder The bismuth-based glass according to any one of the first to fourth aspects of the present invention, wherein the bismuth-based glass is from 1% by volume to 40% by volume. The sealing material according to claim 8, wherein the refractory filler powder is selected from the group consisting of cordierite, strontium zinc ore, alumina, zirconium phosphate-based compound, zircon, zirconia, tin oxide, quartz glass, One or more of β-eucryptite and spodumene. The sealing material according to claim 8 or 9, wherein the content of the laser absorbing material is 5% by volume or less. The sealing material according to any one of claims 8 to 10, which is used in a laser seal.