WO2024154674A1 - Glass and sealed package - Google Patents

Abstract

The purpose of the present invention is to provide a glass that has excellent airtightness and weather resistance and that has, as compared to conventional products, high water resistance and high binding strength with respect to a substrate. The present invention pertains to: a glass that contains, as indicated in mol% based on oxides, 18.0-38.0% of V₂O₅, 5.0-31.0% of B₂O₃, 9.0-33.0% of P₂O₅, 9.0-33.0% of K₂O, and 10.0-23.0% of CuO; and a sealed package including the glass.

Description

Glass and Sealed Package

The present invention relates to glass and a sealing package, more specifically to a sealing glass, a sealing material, a sealing material paste, and a sealing package. In particular, the present invention relates to glass made of vanadium-based glass with a low melting point and improved water resistance, and a sealing material paste and a sealing package using the same.

Resins and low-melting-point glass are used as sealing materials in the sealing parts of electronic and electrical products such as display panels and semiconductor packages. Low-melting-point glass is becoming more widely used because it has the advantage of being more airtight than resin.

The low-melting glass has traditionally contained lead oxide as its main component (see Patent Document 1), but in recent years, the harmfulness of lead compounds to the human body and the environment has come into question, and there has been a demand for lead-free materials.

Vanadium-based glass, which has a lower softening point than lead-based sealing glass and can be applied at low temperatures, has been proposed as a low-melting glass that does not contain lead oxide, and its practical application is under consideration (see, for example, Patent Document 2). Vanadium-based glass with an even lower softening point (Ts) and improved water resistance has also been proposed (see, for example, Patent Document 3).

Japanese Patent Application Publication No. 2-48430 Japanese Patent Application Publication No. 2009-221048 Japanese Patent Application Publication No. 2010-52990

However, vanadium-based glasses such as those described in Patent Documents 2 and 3 generally do not have sufficient water resistance, and further improvement of their properties is an issue for practical use. In particular, vanadium-phosphorus-based glasses are characterized by excellent glass stability, but have the issue of significantly poor water resistance. In addition, they are used as sealing materials for packages, etc., but vanadium-based glasses have insufficient bonding strength with the substrate, leaving room for improvement.

The present invention therefore aims to provide glass that has excellent airtightness and weather resistance, as well as higher water resistance and stronger bonding strength to the substrate than conventional glass.

As a result of thorough investigation into the above problems, the inventors discovered that a vanadium-phosphorus glass with a specific composition has excellent water resistance while maintaining high glass stability, and also has high bonding strength to the alkaline glass substrates used as the base material for packages.

That is, the present invention is as follows.
1. In mole percent based on oxide,
_{V2O5 is} 18.0% or more and 38.0% or less,
_{B2O3 is} 5.0% or more and 31.0% or less;
_{P2O5 is} 9.0% or more and 33.0% or less;
K ₂ O is 9.0% or more and 33.0% or less;
A glass containing 10.0% or more and 23.0% or less of CuO.
2. The glass according to 1 above, wherein the total content of V ₂ O ₅ , B ₂ O ₃ , P ₂ O ₅ , K ₂ O and CuO (V ₂ O ₅ +B ₂ O ₃ +P ₂ O ₅ +K ₂ O +CuO), expressed in mole % on an oxide basis, is 70.0% or more.
3. The glass according to 1 or 2 above, in which the total content of V ₂ O ₅ and B ₂ O ₃ (V ₂ O ₅ +B ₂ O ₃ ) is 60.0% or less, expressed in mole % on an oxide basis.
4. The glass according to any one of 1 to 3 above, having a glass transition point Tg of 350° C. or lower.
5. The glass according to any one of 1 to 4 above, which has a mass loss rate of 3% or less when immersed in distilled water at 100° C. for 1 hour.
6. A glass paste containing a glass powder made of the glass according to any one of 1 to 5 above and an organic vehicle.
7. A sealed package having a first substrate, a second substrate disposed opposite to the first substrate, and a sealing layer disposed between the first substrate and the second substrate and bonding the first substrate and the second substrate,
The sealing layer comprises, in mole percent on an oxide basis,
_{V2O5 is} 18.0% or more and 38.0% or less,
_{B2O3 is} 5.0% or more and 31.0% or less;
_{P2O5 is} 9.0% or more and 33.0% or less;
K ₂ O is 9.0% or more and 33.0% or less;
A sealed package comprising glass containing 10.0% or more and 23.0% or less of CuO.

The glass of the present invention has a specific composition, which gives it excellent water resistance and excellent bonding strength to alkaline glass substrates used as package base materials. Its use as a sealing material reduces defects during product manufacturing and also reduces product deterioration over time. Therefore, electronic and electrical products sealed using the glass of the present invention are highly reliable and have a long life.

In addition, the glass of the present invention has a low melting point, and sealing can be performed at low temperatures, making it safe to seal and easy to handle. Furthermore, the heating temperature during the sealing operation can be sufficiently ensured, making it possible to perform a stable sealing operation.

FIG. 1 is a cross-sectional view showing the configuration of a semiconductor device according to an embodiment of the present invention. 2(a) to 2(c) are cross-sectional views illustrating a manufacturing process for a semiconductor device according to an embodiment of the present invention.

In this specification, the use of "to" to indicate a range of values means that the values before and after it are included as the lower and upper limits. Furthermore, in this specification, unless otherwise specified, the glass composition (content of each component) is expressed as mole percentage based on oxide, and mole % is simply expressed as "%". In this specification, particle size means the median diameter of the particle size distribution based on volume. Median diameter refers to the median value of the particle size.

<Glass>
The glass of this embodiment is a vanadium-phosphorus glass containing V ₂ O ₅ , B ₂ O ₃ , P ₂ O ₅ , K ₂ O and CuO as essential components. The components of the glass of this embodiment will be described in detail below.

V ₂ O ₅ is a component that acts as a network former in the glass. The content of V ₂ O ₅ in the glass of this embodiment is 18.0% or more and 38.0% or less. When the content of V ₂ O ₅ is 18.0% or more, sufficient low-temperature sealing property can be obtained. When the content of V ₂ O ₅ is 38.0% or less, the deterioration of water resistance can be suppressed. The content of V ₂ O ₅ is preferably 20.0% or more, more preferably 22.0% or more, even more preferably 23.0% or more, and particularly preferably 24.0% or more. The content of V ₂ O ₅ is preferably 36.0% or less, more preferably 33.0% or less, even more preferably 32.0% or less, and particularly preferably 31.0% or less.

B ₂ O ₃ is a component that acts as a network former in glass. The content of B ₂ O ₃ in the glass of this embodiment is 5.0% or more and 31.0% or less. When the content of B 2 O 3 is 5.0% or more, the stability of the glass is improved. When the content of _{B 2 O 3 is 31.0% or less, the deterioration of water resistance can be suppressed. The content of B 2 O 3 is preferably 6.0} % or more, more preferably 7.0% or more, even more preferably 7.5% or more, and particularly preferably 8.0% or more. The content of B ₂ O ₃ is preferably 23.0% or less, more preferably 17.0% or less, even more preferably 16.5% or less, and particularly preferably 16.0% or less.

P ₂ O ₅ is a component that acts as a network former in glass. The content of P ₂ O ₅ in the glass of this embodiment is 9.0% or more and 33.0% or less. When the content of P 2 O 5 is 9.0% or more, the stability of the glass is improved. When the content of _{P 2 O 5 is 33.0% or less, the deterioration of water resistance can be suppressed. The content of P 2 O 5 is preferably 12.0 % or} more, more preferably 18.0% or more, even more preferably 19.0% or more, and particularly preferably 20.0% or more. The content of _{P 2} O ₅ is preferably 30.0% or less, more preferably 27.0% or less, even more preferably 26.0% or less, and particularly preferably 25.0% or less.

K ₂ O is a component that lowers the softening point of glass in glass. The content of K ₂ O in the glass of this embodiment is 9.0% or more and 33.0% or less. When the content of K ₂ O is 9.0% or more, the stability of the glass is improved. When the content of K ₂ O is 33.0% or less, the decrease in water resistance can be suppressed. The content of K ₂ O is preferably 12.0% or more, more preferably 18.0% or more, even more preferably 19.0% or more, and particularly preferably 20.0% or more. The content of P ₂ O ₅ is preferably 30.0% or less, more preferably 27.0% or less, even more preferably 26.0% or less, and particularly preferably 25.0% or less.

CuO is a component that mainly improves water resistance. The CuO content in the glass of this embodiment is 10.0% or more and 23.0% or less. When the CuO content is 10.0% or more, water resistance can be improved. When the CuO content is 23.0% or less, a decrease in the bonding strength with the substrate and low-temperature sealing properties can be suppressed. The CuO content is preferably 11.0% or more, more preferably 12.0% or more, even more preferably 12.5% or more, and particularly preferably 13.0% or more. The CuO content is preferably 21.0% or less, more preferably 19.0% or less, even more preferably 18.0% or less, and particularly preferably 17.0% or less.

In the glass of this embodiment, the total content of _V2O5 , _B2O3 , _{P2O5 , K2O, and CuO (V2O5+B2O3+P2O5 + K2O + CuO ) is} preferably _70.0 % or more, more preferably 80.0% _or more, even more preferably 90.0% or more, _particularly preferably 95.0% _{or more, and most preferably 100.0%. By having V2O5 + B2O3 + P2O5} + _K2O +CuO be 70.0% or more, _the water resistance can be further improved.

In the glass of this embodiment, the total content of V ₂ O ₅ and B ₂ O ₃ (V ₂ O ₅ +B ₂ O ₃ ) is preferably 60.0% or less, more preferably 55.0% or less, even more preferably 50.0% or less, and particularly preferably 45.0% or less. By having V ₂ O ₅ +B ₂ O ₃ be 60.0% or less, the water resistance can be further improved. The lower limit of V ₂ O ₅ +B ₂ O ₃ is not particularly limited, but is preferably 25.0% or more, more preferably 30.0% or more, and even more preferably 35.0% or more. By having V ₂ O ₅ +B ₂ O ₃ be 25.0% or more, the stability of the glass is further improved and sufficient low-temperature sealing property is obtained.

Other components include MgO, CaO, SrO, _TeO2 , ZnO, _BaO , _SiO2 , TiO2, _CeO2 , _La2O3 , _{CoO, MoO3, Sb2O3, WO3, GeO2, Nb2O5 , Ta2O5 , Fe2O3 , etc. , and can be} included within a range that does not impair _the effects of the present invention.

The glass of this embodiment preferably contains substantially no PbO. PbO is a component that places a large burden on the environment and human body, and is undesirable for use in the product itself. In this specification, "substantially no PbO" means that the amount contained in the glass is 0.1 mass% or less.

By using the above formulation, it is possible to obtain a lead-free glass for sealing that has excellent water resistance and excellent bonding strength to the alkaline glass substrate used as the base material for the package.

The glass of this embodiment preferably has a mass loss rate of 3% or less when immersed in distilled water at 100°C for 1 hour, more preferably 2% or less, and even more preferably 1% or less. A mass loss rate of 3% or less suppresses the escape of glass components due to contact with moisture, prevents deterioration of the glass, and fully functions as a sealing material. This prevents deterioration of the product over time and further improves its lifespan. In this specification, "distilled water" refers to water with an electrical conductivity of 2.9 μS/cm or less.

The glass of this embodiment preferably has a glass transition point Tg of 350°C or less, more preferably 345°C or less, and even more preferably 340°C or less. If the glass transition point is 350°C or less, the temperature during sealing can be lowered, making it possible to carry out sealing processing at low temperatures, thereby reducing the thermal impact on the workpiece and reducing thermal energy consumption. In addition, since work can be carried out at low temperatures, sealing operations can be carried out safely and reliably. There is no particular lower limit for the glass transition point, but from the viewpoint of glass stability, it is usually preferable for it to be 300°C or higher.

The glass of the present embodiment preferably has a maximum bonding strength of 5 kgf/cm2 or more, more preferably 6 kgf/ ^cm2 or more, and even more preferably 7 kgf/cm2 or ^more , as measured by the following steps (1) to ( ⁶ ).
(1) A sealing material paste is prepared by adding a thinner solution of ethyl cellulose to glass powder adjusted to a particle size of 100 μm or less in a mass ratio of 10:1.
(2) A sealing material paste is applied to approximately the center of a sealing substrate made of soda lime glass (area of application region: 10 mm×10 mm×0.5 mm), and then pre-baked under the following conditions.
Pre-firing conditions: The material was heated to 230°C at a heating rate of 5°C/min, and then held at 230°C for 30 minutes. The material was then heated to 330-380°C at a heating rate of 5°C/min in accordance with the softening point, and then held at each top temperature for 20 minutes.
(3) After laminating a soda lime glass substrate made of the same material as the sealing substrate having the sealing material layer, a 200 g weight is placed above the application area of the sealing material paste to apply pressure, and then the resulting product is fired to produce a sealed body.
Conditions for main firing: The temperature is raised to the main firing temperature at a heating rate of 5° C./min, and then the main firing temperature is maintained for 20 minutes. The main firing temperature is 430° C., 450° C., 470° C., or 490° C.
(4) A test specimen is prepared by attaching a block to both sides of the sealing body in the plate thickness direction using double-sided tape or epoxy resin. At this time, the sealing material paste applied in the square shape in the operation (1) is spread into a substantially circular shape through (2) and (3).
(5) Using a Tensilon universal testing machine (for example, ORIENTEC RTC-1210), the position of the block at the bottom of the plate thickness direction of the test specimen is fixed, and then a tensile stress of 0.3 mm/min is applied to measure the maximum load. The maximum load is measured three times and the average value is calculated to be the maximum load.
(6) Calculate the joint strength from the maximum load value obtained in (5) using the following formula.
Bonding strength (kgf/cm ² )=maximum load (kgf)/bonding area after sealing test (cm ² )
The adhesive area after the sealing test is determined by measuring the length and width of the adhesive region between the soda lime glass substrate and the sealing material in the test specimen, approximating the region to a circle having a diameter equal to the average of the lengths, and calculating the area.
The temperature of the main baking is set to 430° C., 450° C., 470° C. or 490° C., and the bonding strength is measured in each case according to steps (1) to (6). The maximum bonding strength among the bonding strengths thus measured is defined as the maximum bonding strength.

<Sealing material>
The sealing material of this embodiment may be prepared by placing a powder mixture of the raw materials in a container such as a platinum crucible so as to have the above-mentioned blending ratio, heating the mixture in a heating furnace such as an electric furnace for a predetermined time to melt and vitrify the mixture, forming the molten material into a sheet using a water-cooled roller, and pulverizing the sheet to an appropriate particle size using a pulverizer to obtain a lead-free glass for sealing. The particle size of the lead-free glass for sealing is preferably in the range of 0.05 to 100 μm, and the coarse particles resulting from the pulverization may be removed by classification. However, in the case of a lead-free glass for sealing used as a sealant for an ultra-thin display panel for a small device, the particle size is preferably 10 μm or less, and more preferably 6 μm or less.

For the grinding, various dry grinding machines such as ball mills that have been widely used in the manufacture of glass powders can be used, but wet grinding is preferable to obtain a fine particle size of 3 μm or less. Wet grinding is performed in an aqueous solvent such as water or an alcohol solution using grinding media (balls or beads) made of alumina or zirconia with a diameter of 5 mm or less, and it is possible to grind the material even finer than with dry grinding. However, since it is fine grinding using an aqueous solvent, it is preferable that the glass composition to be ground has high water resistance.

The sealing material of this embodiment can be composed only of the lead-free glass for sealing obtained as described above, but in general, it is preferable to mix an inorganic filler such as a low expansion filler with the lead-free glass for sealing as necessary. The amount of inorganic filler mixed is set appropriately depending on the purpose, but is preferably 40 volume % or less with respect to the sealing material. By mixing the inorganic filler at 40 volume % or less, it is possible to suppress a decrease in the fluidity of the sealing material during sealing and improve the bonding strength with the substrate. The sealing material contains lead-free glass for sealing and preferably 0 to 40 volume % of inorganic filler. There is no particular lower limit on the amount of inorganic filler contained.

An example of an inorganic filler is a low expansion filler. A low expansion filler has a thermal expansion coefficient lower than that of the lead-free glass used for sealing. The sealing material may contain inorganic fillers other than the low expansion filler. As described above, the content of the low expansion filler is preferably 40% by volume or less. There is no particular lower limit to the content of the low expansion filler, and it is set appropriately depending on the difference in the thermal expansion coefficient between the lead-free glass used for sealing and the semiconductor substrate for elements or the sealing substrate. However, in order to obtain practical blending effects (adjusting the thermal expansion coefficient of the sealing material and improving the sealing strength), it is preferable to blend at 5% by volume or more.

Examples of the low expansion filler include at least one selected from silica, alumina, zirconia, zirconium silicate, aluminum titanate, mullite, cordierite, eucryptite, spodumene, zirconium phosphate compounds, tin oxide compounds, and quartz solid solutions. Examples of the zirconium phosphate compounds include (ZrO) ₂ P ₂ O ₇ , NaZr ₂ (PO ₄ ) ₃ , KZr ₂ (PO ₄ ) ₃ , Ca _0.5 Zr ₂ (PO ₄ ) ₃ , NbZr (PO ₄ ) ₃ , Zr ₂ (WO ₃ ) (PO ₄ ) ₂ , and composite compounds thereof.

The sealing material paste of this embodiment may be a mixture of a sealing material and an organic vehicle. The organic vehicle may be, for example, a solvent in which a resin, which is a binder component, is dissolved.

Specific examples of organic vehicles include resins such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, oxyethyl cellulose, benzyl cellulose, propyl cellulose, and nitrocellulose dissolved in solvents such as terpineol, texanol, butyl carbitol acetate, and ethyl carbitol acetate.

Examples of organic vehicles include acrylic resins such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate dissolved in solvents such as methyl ethyl ketone, terpineol, texanol, butyl carbitol acetate, and ethyl carbitol acetate. In this specification, (meth)acrylate means at least one of acrylate and methacrylate.

Also, examples of organic vehicles include polyalkylene carbonates such as polyethylene carbonate and polypropylene carbonate dissolved in solvents such as triethyl acetyl citrate, propylene glycol diacetate, diethyl succinate, ethyl carbitol acetate, triacetin, texanol, dimethyl adipate, ethyl benzoate, and mixtures of propylene glycol monophenyl ether and triethylene glycol dimethyl ether.

The mixing ratio of the sealing material and the organic vehicle is appropriately set according to the desired paste viscosity, etc., and is not particularly limited, but a mass ratio of about 60:40 to 90:10 is usually preferable. The viscosity of the sealing material paste can be adjusted to match the viscosity of the device used to apply it to the sealing substrate or the semiconductor substrate for elements, and can be adjusted by the mixing ratio of the organic resin (binder component) and the solvent, and the mixing ratio of the sealing material and the organic vehicle. The sealing material paste may contain additives known in glass pastes, such as antifoaming agents and dispersants. The sealing material paste can be prepared by known methods using a rotary mixer equipped with stirring blades, a roll mill, etc.

<Sealed package>
The above-mentioned lead-free glass for sealing, sealing material, and sealing material paste are used in a sealing process (for example, a bonding process between a semiconductor substrate for an element and a sealing substrate) for semiconductor devices, etc. Fig. 1 shows an example of the configuration of a semiconductor device using the lead-free glass for sealing, sealing material, and sealing material paste of this embodiment.

The semiconductor device 1 shown in FIG. 1 may include, but is not limited to, a pressure sensor, an acceleration sensor, a gyro sensor, a micromirror, a MEMS such as an optical modulator, an optical device using a CCD element or a CMOS element, etc.

The semiconductor device 1 comprises an element semiconductor substrate 2 and a sealing substrate 3. The element semiconductor substrate 2 may be of any of a variety of semiconductor substrates, such as a Si substrate. The sealing substrate 3 may be a semiconductor substrate (such as a Si substrate), a glass substrate, or a ceramic substrate. An element portion 4 corresponding to the semiconductor device 1 is provided on the surface 2a of the element semiconductor substrate 2. The element portion 4 includes a sensor element, a mirror element, a light modulation element, a light detection element, and the like, and has a variety of known structures. The semiconductor device 1 is not limited to the structure of the element portion 4.

A first sealing region 5 is provided on the surface 2a of the element semiconductor substrate 2 along the outer periphery of the element portion 4. The first sealing region 5 is provided so as to surround the element portion 4. A second sealing region 6 corresponding to the first sealing region 5 is provided on the surface 3a of the sealing substrate 3. The element semiconductor substrate 2 and the sealing substrate 3 are arranged with a predetermined gap between them, so that the surface 2a having the element portion 4 and the first sealing region 5 faces the surface 3a having the second sealing region 6. The gap between the element semiconductor substrate 2 and the sealing substrate 3 is sealed with a sealing layer 7.

The sealing layer 7 is formed between the sealing region 5 of the element semiconductor substrate 2 and the sealing region 6 of the sealing substrate 3 so as to seal the element portion 4. The element portion 4 is hermetically sealed in a package made up of the element semiconductor substrate 2, the sealing substrate 3, and the sealing layer 7. The sealing layer 7 is made of a molten and fixed layer of the sealing material of this embodiment. The inside of the package is hermetically sealed in a state according to the semiconductor device 1. For example, if the semiconductor device 1 is a MEMS, the inside of the package is generally hermetically sealed in a vacuum state.

Next, the manufacturing process of the semiconductor device 1 of this embodiment will be described with reference to FIG. 2. First, as shown in FIG. 2(a), a sealing material layer (fired layer of sealing material) 8 is formed in the sealing region 6 of the sealing substrate 3. To form the sealing material layer 8, first, a sealing material paste is applied to the sealing region 6, and then dried to form a coating layer of the sealing material paste. The specific configurations of the sealing material and the sealing material paste are as described above.

The sealing material paste is applied onto the sealing area 6 by using a printing method such as screen printing or gravure printing, or is applied along the sealing area 6 using a dispenser or the like. The applied layer of the sealing material paste is dried, for example, at a temperature of 120°C or higher for 10 minutes or more. The drying process is carried out to remove the solvent in the applied layer. If the solvent remains in the applied layer, the binder component may not be sufficiently removed in the subsequent firing process.

The coating layer of the sealing material paste described above is fired to form the sealing material layer 8. In the firing process, the coating layer is first heated to a temperature below the glass transition point of the lead-free glass for sealing, which is the main component of the sealing material, to remove the binder components in the coating layer, and then heated to a temperature above the softening point of the lead-free glass for sealing, to melt the lead-free glass for sealing and bake it onto the sealing substrate 3. In this way, the sealing material layer 8 consisting of a fired layer of the sealing material is formed.

Next, as shown in FIG. 2(b), the sealing substrate 3 having the sealing material layer 8 and the element semiconductor substrate 2 having the element portion 4 prepared separately are laminated via the sealing material layer 8 so that the surfaces 2a and 3a face each other. A gap is formed on the element portion 4 of the element semiconductor substrate 2 based on the thickness of the sealing material layer 8. After this, the laminate of the sealing substrate 3 and the element semiconductor substrate 2 is heated to a temperature equal to or higher than the softening point of the sealing lead-free glass in the sealing material layer 8, and the sealing lead-free glass is melted and solidified to form a sealing layer 7 that hermetically seals the gap between the element semiconductor substrate 2 and the sealing substrate 3 (FIG. 2(c)).

In this case, the lead-free glass for sealing has good adhesion between the semiconductor substrate 2 and the sealing layer 7, and the sealing layer 7 provides an improved airtight seal. Furthermore, the lead-free glass for sealing has excellent water resistance, so it does not adsorb moisture in the air and does not generate water vapor as an outgas when heated and melted during the sealing process, so the functionality of the semiconductor device is not compromised. Therefore, a semiconductor device 1 that has excellent device characteristics and reliability in addition to airtight sealability can be provided with good reproducibility.

Although the above description has been given using semiconductor devices as an example, there are no particular limitations on the objects that can be sealed using the glass of this embodiment, and examples include openings and joints of various electronic components and electrical products such as electron tubes, fluorescent display tubes, fluorescent display panels, plasma display panels, organic EL display panels, backlight panels for liquid crystal displays, and semiconductor packages.

Specific examples of the present invention and the results of its evaluation will be described below. Note that the following description does not limit the present invention, and modifications can be made in accordance with the spirit of the present invention.

[Glass preparation]
Glass was obtained by mixing raw material powders so as to obtain the compositions shown in Tables 1 and 2, expressed in mole percent on an oxide basis. In Tables 1 and 2, Examples 1 to 8 are working examples, and Examples 9 to 22 are comparative examples. The glasses were evaluated by the following methods, and the results are shown in Tables 1 and 2.

[Transition point]
The glass transition point [Tg] of the sample was measured using a differential thermal analyzer (Shimadzu DTG-60H) under the measurement conditions of a heating rate of 10° C./min and a temperature range of 25° C. (room temperature) to 590° C. using α-alumina as a reference (standard sample).

[Water resistance evaluation]
Each glass was melted and hardened in a mold to prepare a glass block, which was then cut and molded into a cube (1 g) to prepare a sample. The sample was immersed in a container containing distilled water, and the container was placed in a thermostatic chamber set at 100° C. After 1 hour, the sample was removed and the mass of the dried sample was measured, and the mass reduction rate relative to the initial mass was calculated using the following formula.
Mass reduction rate ΔW (%)=[mass (g) of sample before water resistance test−mass (g) of sample after water resistance test]÷mass (g) of sample before water resistance test×100

[Bonding strength evaluation]
The bonding strength was determined according to the following steps (1) to (6).
(1) A sealing material paste was prepared by adding a thinner solution of ethyl cellulose to glass powder adjusted to a particle size of 100 μm or less in a mass ratio of 10:1.
(2) The sealing material paste was applied to approximately the center of a sealing substrate made of soda lime glass (area of application region: 10 mm×10 mm×0.5 mm), and then pre-baked under the following conditions.
Pre-firing conditions: The material was heated to 230°C at a heating rate of 5°C/min, and then held at 230°C for 30 minutes. Thereafter, the material was heated to 330 to 380°C at a heating rate of 5°C/min in accordance with the softening point, and then held at each top temperature for 20 minutes.
(3) After laminating a soda lime glass substrate made of the same material as the sealing substrate having the sealing material layer, a 200 g weight was placed above the application area of the sealing material paste to apply pressure, followed by main firing to produce a sealed body.
Conditions for main firing: The temperature was raised to the main firing temperature at a heating rate of 5° C./min, and then the main firing temperature was maintained for 20 minutes. The main firing temperature was 430° C., 450° C., 470° C., or 490° C.
(4) A test specimen was prepared by attaching a block to both sides of the sealing body in the thickness direction via double-sided tape or epoxy resin. At this time, the sealing material paste applied in the square shape in the operation (1) was spread in a substantially circular shape through (2) and (3).
(5) Using a Tensilon universal testing machine (for example, ORIENTEC RTC-1210), the position of the block at the bottom of the plate thickness direction of the test specimen is fixed, and then a tensile stress of 0.3 mm/min is applied to measure the maximum load. The maximum load is measured three times and the average value is calculated to be the maximum load.
(6) The bonding strength was calculated from the maximum load value obtained in (5) using the following formula.
Bonding strength (kgf/cm ² )=maximum load (kgf)/bonding area after sealing test (cm ² )
The adhesive area after the sealing test was determined by measuring the length and width of the adhesive region between the soda lime glass substrate and the sealing material in the test specimen, approximating the region to a circle having a diameter equal to the average of the lengths, and calculating the area.

The firing temperature was set to 430°C, 450°C, 470°C, or 490°C, and the bonding strength was measured using steps (1) to (6). For examples in which the water resistance evaluation result was 3% or less, the maximum bonding strength among the bonding strengths when the firing temperature was set to 430°C, 450°C, 470°C, or 490°C was determined as the maximum bonding strength. The "-" in the "Maximum bonding strength" column in Tables 1 and 2 indicates that the maximum bonding strength was not determined.

As shown in Tables 1 and 2, the glasses of Examples 1 to 8, which are working examples, had a low glass transition point of 350°C or less and were very excellent in water resistance and bonding strength. On the other hand, Examples 9 to 12, 14, 16, 18 to 20, and 22, which are comparative examples, had low water resistance because the CuO content was less than 10.0%. Examples 15 and 17 had low water resistance because the V ₂ O ₅ content was more than 38.0%. Comparative Examples 13 and 21 had a CuO content of more than 23.0%, so the glass transition point exceeded 350°C.

These results show that the sealing material paste obtained using the glass of this embodiment has excellent water resistance and bonding strength to alkaline glass substrates, and is fully suitable for practical use.

The lead-free glass, sealing material, and sealing material paste of the present invention can be used in low temperature ranges, have excellent water resistance, and have good bonding strength to alkaline glass substrates, so they can be widely used for sealing various electronic and electrical products.

This application is based on Japanese Patent Application No. 2023-006166, filed on January 18, 2023, the contents of which are incorporated by reference into this application.

1...semiconductor device, 2...semiconductor substrate for element, 2a, 3a...surface, 3...sealing substrate, 4...element portion, 5...first sealing region, 6...second sealing region, 7...sealing layer, 8...sealing material layer

Claims (7)

In mole percent based on oxide,
_{V2O5 is} 18.0% or more and 38.0% or less,
_{B2O3 is} 5.0% or more and 31.0% or less;
_{P2O5 is} 9.0% or more and 33.0% or less;
K ₂ O is 9.0% or more and 33.0% or less;
A glass containing 10.0% or more and 23.0% or less of CuO. _{2. The glass according to claim 1, wherein the total content of V2O5, B2O3, P2O5, K2O and CuO (V2O5 + B2O3 + P2O5 + K2O + CuO ) , expressed in} mole % on an oxide basis _, is 70.0% or more. _3. The glass according to claim 1 _, wherein the total content of _V2O5 and _B2O3 ( _{V2O5 + B2O3} ), expressed in mole % on an oxide basis _, is 60.0% or less. The glass according to claim 1 or 2, having a glass transition temperature Tg of 350°C or less. The glass according to claim 1 or 2, which has a mass loss of 3% or less when immersed in distilled water at 100°C for 1 hour. A glass paste containing a glass powder made of the glass according to claim 1 or 2 and an organic vehicle. A sealed package including a first substrate, a second substrate disposed opposite to the first substrate, and a sealing layer disposed between the first substrate and the second substrate and bonding the first substrate and the second substrate,
The sealing layer comprises, in mole percent on an oxide basis,
_{V2O5 is} 18.0% or more and 38.0% or less,
_{B2O3 is} 5.0% or more and 31.0% or less;
_{P2O5 is} 9.0% or more and 33.0% or less;
K ₂ O is 9.0% or more and 33.0% or less;
A sealed package comprising glass containing 10.0% or more and 23.0% or less of CuO.

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