JP2019073403A - Vanadium phosphate glass composition and sealing material - Google Patents

Abstract

To provide a vanadium phosphate glass composition that can be sealed at a low temperature without containing environmentally harmful lead or halogen, and a sealing material prepared therewith.SOLUTION: A vanadium phosphate glass composition contains, by mol%, VOof 15-60%, POof 15-40%, KO of 5-30%, RO of more than 0 to 30% (where R is at least one selected from Mg, Ca, Sr and Ba), ZnO of more than 0 to 20%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vanadium phosphate glass which can be hermetically sealed at a low temperature of 400 ° C. or less without containing harmful lead and halogen, and a sealing material using the same.

  Sealing materials are used for semiconductor integrated circuits, quartz oscillators, flat display devices, glass terminals for LDs, and the like.

  Since the above-mentioned sealing material is required to have chemical durability and heat resistance, a glass-based sealing material is used instead of a resin adhesive. Glass-based sealing materials are required to have mechanical strength, fluidity, weather resistance, and other properties, but for sealing electronic components mounted with heat-sensitive elements, the sealing temperature should be as low as possible. Is required. Specifically, sealing at 400 ° C. or lower is required. Therefore, lead borate glasses containing a large amount of PbO having a very large effect of lowering the melting point have been widely used as glasses satisfying the above-mentioned characteristics (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 63-315536 JP 6-24797 A Patent No. 4573204

In recent years, environmental problems have been pointed out for PbO contained in lead borate glasses, and it is desirable to replace lead borate glasses with glasses that do not contain PbO. Therefore, various low melting glasses have been developed as substitutes for lead borate glasses. Among them, the Bi ₂ O ₃ -B ₂ O ₃ glass described in Patent Document 2 is expected as an alternative candidate for lead borate glasses, but the sealing temperature is as high as 450 ° C. or higher, and sealing is performed at a lower temperature. It can not be used for applications that require stopping.

In Patent Document 3, although AgI-Ag 2 _O-based glass is disclosed as sealable glass at a low temperature of 400 ° C. or less, halogen has also been pointed out on environmental issues, halogen-free glass Is desired.

In view of the above, it is an object of the present invention to provide a vanadium phosphate glass composition that can be sealed at low temperatures without containing lead and halogen harmful to the environment, and a sealing material using the same. Do.

The vanadium phosphate glass composition of the present invention is, in mole%, V ₂ O ₅ 15-60%, P ₂ O ₅ 15-40%, K ₂ O 5-30%, RO over 0-30% (but where R is characterized in that it contains at least one selected from Mg, Ca, Sr and Ba), and more than 0 to 20% of ZnO.

The vanadium phosphate glass composition of the present invention achieves a low softening point by containing 15% or more of V ₂ O ₅ and ₅ % or more of K ₂ O. Moreover, high weather resistance is achieved by containing RO and ZnO as essential components. In general, when the melting point of glass is lowered, it does not vitrify or phase separation occurs, and it tends to be difficult to obtain a homogeneous glass, but the glass is stable because it contains 15% or more of P ₂ O ₅ And a homogeneous glass can be obtained.

The vanadium phosphate glass composition of the present invention preferably further contains, on a molar basis, 10 to 10% of Bi ₂ O _{3 and} 0 to 5% of TeO ₂ .

  The vanadium phosphate glass composition of the present invention preferably contains substantially no PbO or halogen. The halogen includes halides as well as halogen, fluorine, chlorine, bromine and iodine. The halides are fluorides, chlorides, bromides and iodides. Here, "substantially free of PbO and halogen" in the present invention refers to the case where the content of each of PbO and halogen in the glass composition is 1000 ppm or less.

  The sealing material of the present invention is characterized by containing 50 to 100% by volume of a glass powder comprising the above vanadium phosphate glass composition and 0 to 50% by volume of a refractory filler powder.

  The sealing material of the present invention preferably has a softening point of 400 ° C. or less.

  It is possible to provide a vanadium phosphate glass composition that can be sealed at low temperature without containing lead and halogen harmful to the environment, and a sealing material using the same.

It is a schematic diagram which shows the measurement curve obtained by a macro-type differential thermal analyzer.

The vanadium phosphate glass composition of the present invention is, in mole%, V ₂ O ₅ 15-60%, P ₂ O ₅ 15-40%, K ₂ O 5-30%, RO over 0-30% (but where R contains at least one selected from Mg, Ca, Sr and Ba), and more than 0 to 20% of ZnO. The reasons for limiting the glass composition as described above are as follows. In the following description regarding the content of each component, “%” means “mol%” unless otherwise noted.

V ₂ O ₅ is a component that forms a glass network and lowers the softening point. The content of V ₂ O ₅ is 15 to 60%, preferably 25 to 50%, particularly 30 to 40%. When the content of V ₂ O ₅ is too small, the softening point becomes high, and low temperature sealing tends to be difficult. On the other hand, when the content of V ₂ O ₅ is too large, the weather resistance tends to be lowered.

P ₂ O ₅ is a component that forms a glass network. The content of P ₂ O ₅ is 15 to 40%, preferably 20 to 35%, particularly 22 to 30%. When the content of P ₂ O ₅ is too small, the glass becomes thermally unstable, and the glass tends to be devitrified at the time of melting or firing. On the other hand, when the content of P ₂ O ₅ is too large, the softening point becomes high, low temperature sealing becomes difficult, and the weather resistance is easily lowered.

K ₂ O is a component that lowers the softening point. The content of K ₂ O is 5 to 30%, preferably 8 to 25%, particularly 10 to 20%. When the content of K ₂ O is too small, the softening point becomes high, and low temperature sealing tends to be difficult. On the other hand, when the content of K ₂ O is too large, the glass becomes thermally unstable, and the glass tends to be devitrified at the time of melting or firing, and the weather resistance tends to be lowered.

  RO (wherein R is at least one selected from Mg, Ca, Sr and Ba) is a component that stabilizes the glass thermally and enhances the weatherability. The total content of RO is more than 0 to 30%, preferably 5 to 25%, particularly 10 to 20%. If the content of RO is too small, the weather resistance tends to be reduced. On the other hand, when the content of RO is too large, the softening point becomes high, and low temperature sealing tends to be difficult.

  In addition, the preferable range of content of each component of RO is as follows.

  Among RO, BaO is a particularly effective component to obtain the above effects. The content of BaO is preferably 0 to 30%, more than 0 to 28%, 5 to 25%, particularly 10 to 20%. When the content of BaO is too large, the softening point becomes high, and low temperature sealing tends to be difficult.

  MgO is a component that thermally stabilizes the glass and enhances the weatherability. The content of MgO is preferably 0 to 10%, 0 to 5%, particularly 0 to 3%. When the content of MgO is too large, the softening point becomes high, and low temperature sealing tends to be difficult.

  CaO is a component that thermally stabilizes the glass and enhances the weatherability. The content of MgO is preferably 0 to 10%, 0 to 5%, particularly 0 to 3%. When the content of CaO is too large, the softening point becomes high, and low temperature sealing tends to be difficult.

  SrO is a component that thermally stabilizes the glass and enhances the weatherability. The content of SrO is preferably 0 to 10%, 0 to 5%, particularly 0 to 3%. When the content of SrO is too large, the softening point becomes high, and low temperature sealing tends to be difficult.

  ZnO is a component that lowers the softening point and enhances the weather resistance. The content of ZnO is more than 0 to 20%, preferably 3 to 17%, particularly 5 to 15%. When the content of ZnO is too small, the softening point becomes high, and low temperature sealing becomes difficult and the weather resistance tends to be deteriorated. On the other hand, when the content of ZnO is too large, the glass is thermally unstable and the glass is easily devitrified at the time of melting or firing.

  The vanadium phosphate glass composition of the present invention may contain the following components in the glass composition in addition to the above components.

Bi ₂ O ₃ is a component that lowers the softening point and enhances the weather resistance. The content of Bi ₂ O ₃ is preferably 0 to 10%, 0.1 to 8%, particularly 1 to 5%. When the content of Bi ₂ O ₃ is too large, the glass is thermally unstable and the glass is likely to be devitrified at the time of melting or firing.

TeO ₂ is a component that lowers the softening point and enhances the weatherability, but containing TeO ₂ causes the glass to be thermally unstable and easily devitrifies, so its content is 0 to 5%, 0 to 2%, particularly preferably not contained.

Li ₂ O is a component that lowers the softening point. The content of Li ₂ O is preferably 0 to 10%, particularly 0 to 5%. When the content of Li ₂ O is too large, the glass becomes thermally unstable, and the glass tends to be devitrified at the time of melting or firing, and the weather resistance tends to be lowered.

Na ₂ O is a component that lowers the softening point. The content of Na ₂ O is preferably 0 to 10%, particularly 0 to 5%. When the content of Na ₂ O is too large, the glass becomes thermally unstable, and the glass tends to be devitrified at the time of melting or firing, and the weather resistance is easily lowered.

Ag ₂ O is a component that lowers the softening point. The content of Ag ₂ O is preferably 0 to 15%, particularly 0 to 10%. When the content of Ag ₂ O is too large, the glass becomes thermally unstable, and the glass tends to be devitrified at the time of melting or firing.

Fe ₂ O ₃ is a component that enhances the weather resistance. The content of Fe ₂ O ₃ is preferably 0 to 10%, particularly 0 to 5%. When the content of Fe ₂ O ₃ is too large, the softening point becomes high, and low temperature sealing tends to be difficult.

Nb ₂ O ₅ is a component that thermally stabilizes the glass to suppress devitrification. The content of Nb ₂ O ₅ is preferably 0 to 10%, and more preferably 0 to 5%. When the content of Nb ₂ O ₅ is too large, the softening point becomes high, and low temperature sealing tends to be difficult.

WO ₃ is a component that thermally stabilizes glass to suppress devitrification. The content of WO ₃ is preferably 0 to 10%, particularly 0 to 5%. When the content of WO ₃ is too large, the softening point becomes high, and low temperature sealing tends to be difficult.

Ga ₂ O ₃ is a component that thermally stabilizes the glass and enhances the weather resistance, but since it is very expensive, its content is preferably less than 0.01%, and particularly preferably not contained.

MnO ₂ , NiO, and CuO are components that thermally stabilize the glass to suppress devitrification, and can be added to less than 2% each. When the content is too large, the glass becomes thermally unstable, and the glass tends to be devitrified at the time of melting or firing.

In addition to the above components, other components such as SiO ₂ , B ₂ O ₃ and Al ₂ O ₃ may be added to the glass composition up to 10% in total.

  The sealing material of the present invention may contain a refractory filler in the glass powder comprising the vanadium phosphate glass composition described above in order to improve the mechanical strength or adjust the thermal expansion coefficient. The mixing ratio is preferably 50 to 100% by volume of glass powder and 0 to 50% by volume of refractory filler, and particularly preferably 60 to 99% by volume of glass powder and 1 to 40% by volume of refractory filler. If the content of the refractory filler is too large, the proportion of the glass powder relatively decreases, and it becomes difficult to secure desired fluidity.

  The refractory filler is not particularly limited, and various materials can be selected. However, those refractory to the above-described glass powder are preferable.

Specifically, NbZr (PO ₄ ) ₃ , Zr ₂ WO ₄ (PO ₄ ) ₂ , zirconium phosphate, zircon, zirconia, tin oxide, aluminum titanate, quartz, β-spodumene, mullite as refractory fillers. Titania, quartz glass, β-eucryptite, β-quartz, willemite, cordierite, NaZr ₂ (PO ₄ ) ₃ -type solid solution such as Sr _0.5 Zr ₂ (PO ₄ ) ₃ alone or 2 More than species can be mixed and used. In addition, as for the particle size of the refractory filler, it is preferable to use one having an average particle size D ₅₀ of about 0.2 to ₂₀ μm. Further, the shape of the refractory filler is not particularly limited, but is preferably approximately spherical.

The softening point of the vanadium phosphate glass composition and the sealing material of the present invention is preferably 400 ° C. or less, 390 ° C. or less, 380 ° C. or less, particularly preferably 370 ° C. or less. If the softening point is too high, the viscosity of the glass becomes high, so the sealing temperature rises, and there is a possibility that the element may be damaged at the time of sealing. The lower limit of the softening point is not particularly limited, but is practically 180 ° C. or more. Here, the "softening point" refers to a value measured by a macroscopic differential thermal analyzer using a glass powder having an average particle diameter D50 of _0.5 to 20 m as a measurement sample. As measurement conditions, measurement is started from room temperature, and the temperature rising rate is 10 ° C./min. The softening point measured by the macroscopic differential thermal analyzer indicates the temperature (Ts) at the fourth inflection point in the measurement curve shown in FIG.

The thermal expansion coefficient (30 to 150 ° C.) of the vanadium phosphate glass composition and the sealing material of the present invention is 170 × 10 ⁻⁷ / ° C. or less, 160 × 10 ⁻⁷ / ° C. or less, particularly 150 × 10 ⁻⁷ / ° C. It is preferable that the temperature is not higher than ° C. When the thermal expansion coefficient is too high, the sealing portion is easily damaged during sealing or after sealing due to the expansion difference with the sealing material. Although the lower limit of the thermal expansion coefficient is not particularly limited, it is practically 50 × 10 ⁻⁷ / ° C. or more.

  Next, a method of producing a glass powder using the vanadium phosphate glass composition of the present invention and an example of using the vanadium phosphate glass composition of the present invention as a sealing material will be described.

First, the raw material powder prepared to have the above composition is melted at 800 to 1200 ° C. for 1 to 3 hours until a homogeneous glass is obtained. Next, the molten glass is formed into a film or the like, and then crushed and classified to prepare a glass powder comprising the vanadium phosphate glass composition of the present invention. Incidentally, it is preferable that the average particle diameter _{D 50} of the glass powder is about 0.2 to 20. If necessary, various refractory filler powders are added to the glass powder.

  Next, a vehicle is added to glass powder (or mixed powder of glass powder and refractory filler powder) and kneaded to prepare a glass paste. The vehicle mainly consists of an organic solvent and a resin, and the resin is added for the purpose of adjusting the viscosity of the paste. Moreover, surfactant, a thickener, etc. can also be added as needed.

The organic solvent preferably has a low boiling point (e.g., a boiling point of 300 [deg.] C. or less) and a small amount of residue after firing and does not alter vanadium phosphate glass, and its content is 10 to 40% by mass Is preferred. Examples of the organic solvent include propylene carbonate, toluene, N, N'-dimethylformamide (DMF), 1,3-dimethyl-2-imidazolidinone (DMI), dimethyl carbonate, butyl carbitol acetate (BCA), isoamyl acetate, It is preferable to use dimethyl sulfoxide, acetone, methyl ethyl ketone and the like. Further, it is more preferable to use a higher alcohol as the organic solvent. Higher alcohols can be pasted without the addition of resin to the vehicle because they are themselves viscous. In addition, pentanediol and a derivative thereof, specifically, diethylpentanediol (C ₉ H ₂₀ O ₂ ) can also be used as a solvent since the viscosity is excellent.

  In addition to the resin having a low decomposition temperature and a small amount of residue after firing, it is preferable that the resin not easily deteriorate the vanadium phosphate glass, and the content thereof is preferably 0.1 to 20% by mass. It is preferable to use nitrocellulose, a polyethylene glycol derivative, polyethylene carbonate, an acrylic ester (acrylic resin) etc. as resin.

  Then, using a dispenser such as a dispenser or a screen printing machine at the sealing position of the paste between the first member made of metal, ceramic or glass and the second member made of metal, ceramic or glass It is applied, dried and heat treated at 200-400 ° C. By this heat treatment, the glass powder softens and flows to seal the first and second members.

  The vanadium phosphate glass composition and the sealing material of the present invention can be used for the purpose of coating, filling, etc. besides sealing. Moreover, it can also be used in forms other than a paste, specifically, powder, a green sheet, a tablet, etc. state.

  The invention will be described in detail on the basis of examples. Tables 1 and 2 show Examples (Sample Nos. 1 to 7) and Comparative Examples (Sample Nos. 8 to 10) of the present invention.

First, glass raw materials such as various oxides and carbonates are prepared so as to obtain the glass composition shown in the table, and a glass batch is prepared, and this glass batch is put in a platinum crucible and 1 to 800 to 1200 ° C. It melted for 3 hours. Next, a part of the molten glass was poured out into a stainless steel mold as a sample for TMA (pushing rod type thermal expansion coefficient measurement), and the other molten glass was formed into a film by a water cooling roller. In addition, the sample for TMA performed the predetermined slow cooling process (annealing) after shaping | molding. Finally, the film-like glass was crushed by a ball mill, and then passed through a sieve with an opening of 75 μm to obtain a glass powder having an average particle diameter D ₅₀ of about 10 μm.

  After that, No. 1 which mixes fireproof filler. For the samples 1 and 2, as shown in the table, the obtained glass powder and the refractory filler powder were mixed to obtain a mixed powder.

As the refractory filler powder, Zr ₂ WO ₄ (PO ₄ ) ₂ (indicated as ZWP in the table) was used. The average particle diameter _{D 50} of the refractory filler powder was about 10 [mu] m.

  The obtained mixed powder was fired at 390 ° C. for 30 minutes to obtain a fired body. The obtained fired body was used as a sample for TMA.

  No. The glass transition point, the thermal expansion coefficient, the softening point, the flowability, the devitrification resistance and the weather resistance were evaluated for the samples 1 to 10.

  The glass transition point and the thermal expansion coefficient (30 to 150 ° C.) were measured with a TMA apparatus for a sample for TMA.

  The softening point was measured by a macroscopic differential thermal analyzer. The measurement atmosphere was air, the temperature rising rate was 10 ° C./min, and the measurement was started from room temperature.

  The liquidity was assessed as follows. 1 g of the powder sample was put into a die with a diameter of 10 mm and press-formed, and then it was fired at 390 ° C. for 30 minutes on a stainless steel plate. The thing whose flow diameter of a sintered body is 10 mm or more was evaluated as "(circle)" and the thing less than 10 mm as "x".

  The devitrification resistance was evaluated as follows. The surface state of the sintered body was observed using an optical microscope (magnification: 100 ×). Evaluations were made as “○” where no crystals were found on the surface of the fired body, and as “×” when crystals were found on the surface of the fired body.

  The weatherability was evaluated as follows. After the fired body was kept at a temperature of 121 ° C. and a relative humidity of 95% for 24 hours, the appearance of the fired body was observed. The thing in which the change in external appearance was not seen before and after holding | maintenance was evaluated as "(circle)", and the thing in which the change in external appearance was seen was evaluated as "x".

As is apparent from the table, the Nos. 1 and 2 which are examples of the present invention. The samples 1 to 7 were excellent in flowability, devitrification resistance and weatherability. On the other hand, No. 1 as a comparative example. The sample No. 8 was inferior in fluidity because it did not contain K ₂ O. No. Sample No. 9 was inferior in weatherability because it did not contain RO. No. Sample No. 10 was inferior in devitrification resistance because the content of P ₂ O ₅ was too low.

  The vanadium phosphate glass composition and the sealing material of the present invention are suitable for sealing a semiconductor integrated circuit, a quartz oscillator, a flat display device, and a glass terminal for LD.

Claims (5)

V ₂ O ₅ 15 to 60%, P ₂ O ₅ 15 to 40%, K ₂ O 5 to 30%, in mole%, RO (wherein R is at least one selected from Mg, Ca, Sr and Ba) Vanadium phosphate glass composition characterized by containing more than 0 and 30% and ZnO more than 0 and 20%. The vanadium phosphate glass composition according to claim 1, further comprising, on a molar basis, 10 to 10% of Bi ₂ O _{3 and} 0 to 5% of TeO ₂ .   The vanadium phosphate glass composition according to claim 1 or 2, which is substantially free of PbO and halogen.   A sealing material comprising 50 to 100% by volume of a glass powder comprising the vanadium phosphate glass composition according to any one of claims 1 to 3 and 0 to 50% by volume of a refractory filler powder. .   The sealing material according to claim 4, wherein the softening point is 400 ° C. or less.