JP2020186155A - Glass composition and sealing material - Google Patents

Abstract

To provide a glass composition that can be sealed at low temperature without containing environmentally harmful lead, and a sealing material including the same.SOLUTION: A glass composition contains, in mol%, TiO2 2-30%, TeO2 10-80%, and MoO3 5-60%.SELECTED DRAWING: Figure 1

Description

The present invention relates to a glass composition that can be air-sealed at a low temperature without containing harmful lead, and a sealing material using the same.

Sealing materials are used for semiconductor integrated circuits, crystal 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-based adhesive. The sealing material is further required to have characteristics such as mechanical strength, fluidity, and weather resistance. However, when sealing electronic components equipped with heat-sensitive elements, the sealing temperature should be as low as possible. Required. Specifically, sealing at a temperature lower than 450 ° C. is required. Therefore, as a glass satisfying the above characteristics, a lead boric acid-based glass containing a large amount of PbO, which has an extremely large effect of lowering the melting point, has been widely used (see, for example, Patent Document 1).

JP-A-63-315536 Japanese Unexamined Patent Publication No. 6-24797

In recent years, environmental problems have been pointed out with respect to PbO contained in lead boric acid-based glass, and it is desired to replace lead boric acid-based glass with glass containing no PbO. Therefore, various low melting point glasses have been developed as alternatives to lead boric acid-based glass. Among them, Bi ₂ O _3- B ₂ O ₃ series glass described in Patent Document 2 is expected as an alternative candidate for lead boric acid based glass, but the sealing temperature is as high as 450 ° C. or higher, and the sealing temperature is lower. It cannot be used for applications that require sealing.

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

The glass composition of the present invention, in _{mol%, TiO 2 2~30%, TeO} 2 10~80%, characterized in that it contains MoO 3 5 to 60%.

The glass composition of the present invention, by containing MoO ₃ 5% or more, and achieve low softening point. In general, when the melting point of glass is lowered, it tends not to be vitrified or phase separation occurs, making it difficult to obtain a homogeneous glass. However, in the present invention, the content of TiO ₂ is 2% or more, and that of TeO ₂ . Since the content is specified to be 10% or more, the glass is stabilized and a homogeneous glass can be obtained.

The glass composition of the present invention, furthermore, in _{mol%, Li 2 O 0~30%,} Na 2 O 0~30%, K 2 O 0~30%, Al 2 O 3 0~30%, CuO 0~ _{30%, WO 3 0~25%,} Ag 2 O 0~20%, preferably contain 0% AgI.

The glass composition of the present invention, furthermore, in _mol%, preferably contains P ₂ O 5 0~5%.

The sealing material of the present invention is characterized by containing 40 to 100% by volume of a glass powder composed of the above glass composition and 0 to 60% by volume of a refractory filler powder.

The sealing material of the present invention is preferably used for crystal oscillator applications.

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

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

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

The glass composition of the present invention, in _{mol%, TiO 2 2~30%, TeO} 2 10~80%, containing MoO 3 5 to 60%. The reasons for limiting the glass composition as described above are shown below. In the following description of the content of each component, "%" means "mol%" unless otherwise specified.

TiO ₂ is a component that thermally stabilizes glass and improves weather resistance. The content of TiO ₂ is 2 to 30%, preferably 3 to 20%, particularly 4 to 10%. If the content of TiO ₂ is too small, the glass becomes thermally unstable, the glass tends to be devitrified during melting or firing, and the weather resistance tends to decrease. On the other hand, if the content of TiO ₂ is too high, the viscosity (softening point, etc.) of the glass becomes high, which makes low-temperature sealing difficult and the glass becomes thermally unstable, causing the glass to become unstable during melting or firing. It becomes easy to devitrify.

TeO ₂ is a component that forms a glass network and thermally stabilizes the glass. The content of TeO ₂ is 10 to 80%, preferably 15 to 70%, particularly preferably 25 to 60%. If the content of TeO ₂ is too small, the glass becomes thermally unstable, and the glass tends to be devitrified during melting or firing. On the other hand, if the content of TeO ₂ is too large, the viscosity (softening point, etc.) of the glass becomes high, which makes low-temperature sealing difficult and the glass becomes thermally unstable, so that the glass becomes unstable during melting or firing. It becomes easy to devitrify. In addition, the coefficient of thermal expansion of glass tends to be too high.

MoO ₃ is a component that forms a glass network and lowers the viscosity (softening point, etc.) of glass. The content of MoO ₃ is 5 to 60%, preferably 10 to 58%, 15 to 55%, and particularly preferably 20 to 50%. If the content of MoO ₃ is too small, the glass becomes thermally unstable, the glass tends to be devitrified during melting or firing, and the viscosity (softening point, etc.) of the glass becomes high, resulting in low temperature sealing. It will be difficult. On the other hand, if the content of MoO ₃ is too large, the glass becomes thermally unstable, the glass tends to be devitrified at the time of melting or firing, and the coefficient of thermal expansion of the glass tends to be too high.

In addition to the above components, the glass composition of the present invention may contain the following components in the glass composition.

Li ₂ O is a component that lowers the viscosity (softening point, etc.) of glass. The content of Li ₂ O is preferably 0 to 30%, 0 to 20%, 0.1 to 10%, and particularly preferably 1 to 8%. If the content of Li ₂ O is too large, the glass becomes thermally unstable, the glass tends to be devitrified during melting or firing, and the weather resistance tends to decrease.

Na ₂ O is a component that lowers the viscosity (softening point, etc.) of glass. The content of Na ₂ O is preferably 0 to 30%, 0 to 10%, 0 to 6%, particularly 0.1 to 2%. If the Na ₂ O content is too high, the glass becomes thermally unstable, and the glass tends to be devitrified during melting or firing, and the weather resistance tends to decrease.

K ₂ O is a component that lowers the viscosity (softening point, etc.) of glass. The content of K ₂ O 0-30%, 0-10%, 6%, and particularly preferably 0.1% to 2%. If the content of K ₂ O is too large, the glass becomes thermally unstable, the glass tends to be devitrified during melting or firing, and the weather resistance tends to decrease.

Al ₂ O ₃ is a component that improves the weather resistance of glass. The content of Al ₂ O ₃ is preferably 0 to 30%, 0 to 10%, 0 to 6%, particularly 0.1 to 2%. If the content of Al ₂ O ₃ is too large, the viscosity (softening point, etc.) of the glass becomes high, and low-temperature sealing becomes difficult.

CuO is a component that lowers the viscosity (softening point, etc.) of glass and lowers the coefficient of thermal expansion of glass. The content of CuO is preferably 0 to 30%, 0 to 10%, 0 to 6%, particularly 0.1 to 2%. If the CuO content is too high, the glass becomes thermally unstable, and the glass tends to be devitrified during melting or firing.

WO ₃ is a component that lowers the coefficient of thermal expansion of glass. The content of WO ₃ is preferably 0 to 25%, 0 to 10%, 0 to 6%, particularly 0.1 to 2%. If the content of WO ₃ is too high, the glass becomes thermally unstable, the glass tends to be devitrified during melting or firing, and the viscosity (softening point, etc.) of the glass becomes high, resulting in low temperature sealing. It will be difficult.

Ag ₂ O is a component that lowers the viscosity (softening point, etc.) of glass. The content of Ag ₂ O is preferably 0 to 20%, 0 to 10%, 0 to 6%, particularly 0.1 to 2%. If the content of Ag ₂ O is too high, the glass becomes thermally unstable, and the glass tends to be devitrified during melting or firing.

AgI is a component that lowers the viscosity (softening point, etc.) of glass. The content of AgI is preferably 0 to 10%, 0 to 5%, particularly 0.1 to 2%. If the content of AgI is too high, the coefficient of thermal expansion of the glass tends to be too high.

P ₂ O ₅ is a component that forms a glass network and thermally stabilizes the glass. The content of P ₂ O ₅ is preferably 0 to 5%, 0 to 2%, and particularly preferably 0 to 1%. If the content of P ₂ O ₅ is too large, the viscosity (softening point, etc.) of the glass becomes high, which makes low-temperature sealing difficult and the weather resistance tends to decrease.

MgO, CaO, SrO, and BaO have the effect of thermally stabilizing the glass and improving the weather resistance, and their contents are 0 to 20%, 0 to 10%, and 0 to 5 in total. %, 0 to 2%, particularly preferably 0 to 1%. If the total amount of MgO, CaO, SrO, and BaO is too large, the glass becomes thermally unstable, and the glass tends to be devitrified during melting or firing. The contents of MgO, CaO, SrO, and BaO are preferably 0 to 10%, 0 to 5%, 0 to 2%, and particularly preferably 0 to 1%, respectively.

ZnO is a component that lowers the viscosity (softening point, etc.) of glass and improves weather resistance. The ZnO content is preferably 0 to 10%, 0 to 5%, 0 to 2%, and particularly preferably 0 to 1%. If the ZnO content is too high, the glass becomes thermally unstable, and the glass tends to be devitrified during melting or firing.

Nb ₂ O ₅ is a component that thermally stabilizes the glass and improves the weather resistance. The content of Nb ₂ O ₅ is preferably 0 to 10%, 0 to 5%, 0 to 2%, and particularly preferably 0 to 1%. If the content of Nb ₂ O ₅ is too large, the viscosity (softening point, etc.) of the glass becomes high, and low-temperature sealing tends to be difficult.

V ₂ O ₅ is a component that forms a glass network and lowers the viscosity (softening point, etc.) of the glass. The content of V ₂ O ₅ is preferably 0 to 10%, 0 to 5%, 0 to 2%, and particularly preferably 0 to 1%. If the content of V ₂ O ₅ is too large, the glass becomes thermally unstable, the glass tends to be devitrified during melting or firing, and the weather resistance tends to decrease.

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

SiO ₂ , GeO ₂ , Fe ₂ O ₃ , NiO, CeO ₂ , B ₂ O ₃ , Sb ₂ O ₃ , La ₂ O ₃ , and ZrO ₂ are components that thermally stabilize the glass and suppress devitrification. Each can be added up to less than 2%. If these contents are too high, the glass becomes thermally unstable, and the glass tends to be devitrified during melting or firing.

For environmental reasons, the glass composition of the present invention preferably contains substantially no PbO. Here, "substantially free of PbO" refers to a case where the content of PbO in the glass composition is 1000 ppm or less.

The sealing material of the present invention contains a glass powder composed of the above glass composition. The sealing material of the present invention may contain a refractory filler powder in order to improve mechanical strength or adjust the coefficient of thermal expansion. The mixing ratio is 40 to 100% by volume of glass powder, 0 to 60% by volume of fire-resistant filler powder, 50 to 99% by volume of glass powder, 1 to 50% by volume of fire-resistant filler powder, and particularly 60 to 95% by volume of glass powder. %, 5 to 40% by volume of the fire resistant filler powder is preferable. If the content of the refractory filler is too large, the proportion of the glass powder is relatively small, and it becomes difficult to secure the desired fluidity.

The refractory filler powder is not particularly limited, and various materials can be selected, but those that do not easily react with the above glass powder are preferable.

Specifically, as refractory fillers, NbZr (PO ₄ ) ₃ , Zr ₂ WO ₄ (PO ₄ ) ₂ , Zr ₂ MoO ₄ (PO ₄ ) ₂ , Hf ₂ WO ₄ (PO ₄ ) ₂ , Hf ₂ MoO ₄ (PO ₄ ) ₂ , zirconium phosphate, zircon, zirconia, tin oxide, aluminum titanate, quartz, β-spojumen, mulite, titania, quartz glass, β-eucryptite, β-quartz, willemite, cordierite , Sr _0.5 Zr ₂ (PO ₄ ) _3, etc. NaZr ₂ (PO ₄ ) type ₃ solid solution, etc. can be used alone or in combination of two or more. It is preferable to use a refractory filler having an average particle diameter D ₅₀ of about 0.2 to ₂₀ μm.

The softening point of the glass composition and the sealing material of the present invention is preferably 400 ° C. or lower, 390 ° C. or lower, 380 ° C. or lower, and particularly preferably 370 ° C. or lower. If the softening point is too high, the viscosity of the glass becomes high, so that the sealing temperature rises, which may deteriorate the element at the time of sealing. The lower limit of the softening point is not particularly limited, but is actually 180 ° C. or higher. Here, the “softening point” refers to a value measured by a macro-type differential thermal analyzer using a glass composition having an average particle diameter D ₅₀ of 0.5 to 20 μm and a sealing material as measurement samples. As the measurement conditions, the measurement is started from room temperature, and the temperature rising rate is 10 ° C./min. The softening point measured by the macro-type differential thermal analyzer refers to the temperature (Ts) of the fourth bending point in the measurement curve shown in FIG.

The coefficient of thermal expansion (30 to 150 ° C.) of the glass composition and the sealing material of the present invention is 20 × ^10-7 / ° C. to 200 × ^10-7 / ° C., 30 × ^10-7 / ° C. to 160 × ^10-7. / ° C., particularly preferably 40 × 10 ^-7 / ° C. to 140 × 10 ^-7 / ° C. If the coefficient of thermal expansion is too low or too high, the sealing portion is likely to be damaged at the time of sealing or after sealing due to the difference in expansion from the material to be sealed.

The glass composition and sealing material of the present invention having the above characteristics are particularly suitable for crystal oscillator applications where sealing at a low temperature is required.

Next, an example of a method for producing a 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.

First, the raw material powder prepared to have the above composition is melted at 800 to 1000 ° C. for 1 to 2 hours until a homogeneous glass is obtained. Next, the molten glass is formed into a film or the like, crushed, and classified to produce a glass powder made of the glass composition of the present invention. The average particle size D ₅₀ of the glass powder is preferably about 2 to 20 μm. If necessary, the sealing material is made by adding various refractory filler powders to the glass powder.

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 for the purpose of adjusting the viscosity of the paste. Further, if necessary, a surfactant, a thickener and the like can be added.

The organic solvent preferably has a low boiling point (for example, a boiling point of 300 ° C. or lower), a small amount of residue after firing, and does not deteriorate the glass, and its content is 10 to 40% by mass. preferable. Examples of the organic solvent include propylene carbonate, toluene, N, N'-dimethylformamide (DMF), 1,3-dimethyl-2-imidazolidinone (DMI), dimethyl carbonate, butylcarbitol acetate (BCA), isoamyl acetate, and the like. 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. Since the higher alcohol has its own viscosity, it can be made into a paste without adding a resin to the vehicle. Further, pentanediol and its derivatives, particularly diethyl pentanediol (C 9 _H 20 _{O 2)} also is excellent in viscosity, it can be used in a solvent.

The resin preferably has a low decomposition temperature, a small amount of residue after firing, and is difficult to deteriorate the glass, and the content thereof is preferably 0.1 to 20% by mass. As the resin, it is preferable to use nitrocellulose, polyethylene glycol derivative, polyethylene carbonate, acrylic acid ester (acrylic resin) and the like.

Next, the paste is applied to the sealing portion between the first member made of metal, ceramic or glass and the second member made of metal, ceramic or glass by using a coating machine such as a dispenser or a screen printing machine. It is applied, dried and heat treated at 300-450 ° C. By this heat treatment, the glass powder softens and flows to seal the first member and the second member.

The glass composition of the present invention can be used for purposes such as coating and filling in addition to sealing applications. Further, it can be used in a form other than paste, specifically, in a state of powder, green sheet, tablet or the like.

The present invention will be described in detail based on examples. Tables 1 and 2 show Examples (Samples Nos. 1 to 11) and Comparative Examples (Samples Nos. 12 and 13) of the present invention.

First, various glass raw materials such as oxides and carbonates are mixed so as to have the glass composition shown in the table, a glass batch is prepared, and then this glass batch is placed in a platinum crucible and heated at 800 to 1000 ° C. for 1 to 1. Melted for 2 hours. Next, a part of the molten glass was poured into a stainless steel mold as a sample for TMA (coefficient of thermal expansion of a push rod type), and the other molten glass was formed into a film by a water-cooled roller. No. which does not contain the refractory filler powder. For No. 2, a sample for TMA was obtained by performing a predetermined slow cooling treatment (annealing) after molding. Finally, the film-shaped glass was pulverized with a ball mill and then passed through a sieve having a mesh size of 75 μm to obtain a glass powder having an average particle diameter D ₅₀ of about 10 μm.

After that, No. 1 in which the refractory filler powder is mixed. For the samples 1, 3 to 12, 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, NbZr (PO ₄ ) ₃ (denoted as NZP in the table) and Zr ₂ WO ₄ (PO ₄ ) ₂ (denoted as ZWP in the table) were used. The average particle size D ₅₀ of the refractory filler powder was about 10 μm.

The obtained mixed powder was calcined at 380 ° C. for 10 minutes to obtain a calcined product. The obtained fired body was used as a sample for TMA.

No. The glass transition point, the coefficient of thermal expansion, the softening point, and the fluidity were evaluated for the samples 1 to 12.

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

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

Liquidity was evaluated as follows. 5 g of the powder sample was placed in a mold having a diameter of 20 mm, press-molded, and then fired on a glass substrate at 380 ° C. for 10 minutes. The fired body having a flow diameter of 19 mm or more was designated as “◯”, and the fired body having a flow diameter of less than 19 mm was designated as “x”.

As is clear from the table, No. 1 which is an example of the present invention. The samples 1 to 11 were excellent in fluidity. On the other hand, No. Since the sample 12 contained an excess of TiO ₂ , it was devitrified during firing. No. The 13 samples were not vitrified due to the excessive content of TeO ₂ .

The glass composition and sealing material of the present invention are suitable for sealing semiconductor integrated circuits, crystal oscillators, flat surface display devices, glass terminals for LD, and aluminum nitride substrates.

Claims (6)

A glass composition comprising TiO _{2 to} 30%, TeO _{2 to} 10 to 80%, and MoO _{3 to} 60% in mol%. Furthermore, in _{mol%, Li 2 O 0~30%,} Na 2 O 0~30%, K 2 O 0~30%, Al 2 O 3 0~30%, 0~30% CuO, WO 3 0~25 The glass composition according to claim 1, wherein the glass composition contains%, Ag ₂ O 0 to 20%, and Ag I 0 to 10%. Furthermore, in _mol%, the glass composition according to claim 1 or 2, characterized in that it contains P ₂ O 5 0 to 5%. A sealing material containing 40 to 100% by volume of a glass powder comprising the glass composition according to any one of claims 1 to 3 and 0 to 60% by volume of a refractory filler powder. The sealing material according to claim 4, wherein the sealing material is used for a crystal oscillator application. A sealing material paste comprising the sealing material according to claim 4 or 5 and a vehicle.