JP5751744B2 - Glass - Google Patents

Description

  The present invention relates to a glass having a low average linear expansion coefficient that is useful as an airtight sealing member for various substrate materials and MEMS devices.

Glass with a low average coefficient of linear expansion is used in a wide range of fields such as substrate materials and heat-resistant glass in the field of precision equipment. In recent years, it has a low average coefficient of linear expansion and is hot for applications such as mirror substrates for telescopes. There is a demand for glass with excellent workability.
Further, in a MEMS (microelectronic mechanical system) device in which a sensor or actuator (mechanical drive mechanism) and an integrated circuit that drives the sensor are mixed, an anode is used as a hermetically sealed method for protecting the inside from external factors. Bonding is used. This anodic bonding is a method of bonding glass and a silicon wafer, and the glass used in this method preferably contains mobile ions and has a low average linear expansion coefficient approximate to that of a silicon wafer.

  There is also an idea that the hermetic sealing substrate is produced by green sheet sintering which is superior to glass in mass productivity. Ceramics such as alumina and cordierite and glass are mixed and sintered. Here, the ceramic functions as an expression element of insulation and high mechanical strength, and the glass functions as a binder for ceramic particles. In this case, when using ceramics such as generally used alumina and cordierite, alumina and cordierite itself have a larger expansion coefficient than silicon. Therefore, the expansion coefficient of filler glass is smaller than that of silicon, and the sintered body is used as a sintered body. It is necessary to adjust the expansion coefficient to approximate silicon.

  In order to use a device in which an integrated circuit and a MEMS device are mixed for consumer use such as a mobile phone, it is necessary to manufacture the device at a low cost. Therefore, the above-mentioned confidential sealing substrate itself needs to be manufactured at a low cost, and the glass is also required to be reduced in cost.

  If the glass can be melted at a low temperature, it leads to low cost. However, in order to melt the glass at a low temperature, it is effective to contain an alkali component, and at the same time, the alkali component is used as a mobile ion at the time of anodic bonding. Function. However, since the alkali component increases the average linear expansion coefficient of the glass, it has been difficult to obtain a low expansion glass that can be melted at a low temperature.

Patent Document 1 discloses low expansion glass, but the thermal expansion coefficient (average linear expansion coefficient) is 36 to 39 × 10 ⁻⁷ ° C.− ¹ , and a sufficiently low average linear expansion coefficient is not obtained. There is no discussion about hot workability such as reheat press.
Further, it is expected that the content of a lithium component preferable as a mobile ion is small and the anodic bonding property is low.
Japanese Unexamined Patent Publication No. 1-93437

An object of the present invention is to provide a glass that has a low average linear expansion coefficient even if it contains a Li ₂ O component, does not cause devitrification even in hot working, and can be melted at a relatively low temperature. It is.

  As a result of intensive studies in view of the above problems, the present inventor has found that the above problems can be solved by defining the content range of specific components, and has completed the present invention. The main configuration is as follows.

(Configuration 1)
It contains SiO ₂ component, B ₂ O ₃ component, Al ₂ O ₃ component and Li ₂ O component in mass% based on oxide, and the total amount of these components is 90% or more,
The mass% ratio Li ₂ O / Al ₂ O _{3 of} these components is 0.9 or more,
Glass whose average linear expansion coefficient in 0-300 degreeC is 30 * 10 < ^-7 > degreeC- ¹ or less.
(Configuration 2)
% By mass based on oxide,
SiO ₂ 64% to 95%
B ₂ O ₃ 2% to 35%
Al ₂ O ₃ 0.1% to 10%
Li ₂ O ₃ 0.1% to 10%
The glass of the structure 1 containing each component of.
(Configuration 3)
% By mass based on oxide,
Na ₂ O component 0-5%, and / or _{K 2} O component 0-5% and / or Cs ₂ O component 0-5%
The glass of the structure 1 or 2 containing each component of these.
(Configuration 4)
% By mass on the oxide basis, the glass according to any one of Na ₂ O component, Li ₂ O component, constituting 1-3 total amount of _{K 2} O component and Cs ₂ O component is less than 17%.
(Configuration 5)
% By mass based on oxide,
MgO component 0-5%, and / or CaO component 0-5%, and / or SrO component 0-5%, and / or BaO component 0-5%,
The glass in any one of the structures 1-4 containing each component of these.
(Configuration 6)
Glass according to any of the 1 to 5, containing 2% 0% _As 2 _{O 3} component and / or _Sb 2 _{O 3} component in weight percent on the oxide basis.
(Configuration 7)
Glass according to any of the 1-6, containing 2% 0% CeO ₂ component and / or the SnO ₂ component in terms of% by mass on the oxide basis.
(Configuration 8)
The glass in any one of the structures 1-7 whose glass transition point is 600 degrees C or less.
(Configuration 9)
Glass temperature according to any of the configurations 1-8 is 1500 ° C. or less when a viscosity is ¹⁰ 3.0 dPa · s.

According to the present invention, the Li ₂ O component is contained, but it has a low average linear expansion coefficient of 30 × 10 ⁻⁷ ° C. ⁻¹ or less, and glass is not easily devitrified even during hot working such as reheat molding. It is possible to obtain glass. In addition, the glass of the present invention can be produced at a low cost because the maximum temperature (hereinafter referred to as “melting temperature”) for obtaining a glass melt from raw materials can be set to 1600 ° C. or lower in the production process. Is

It is a figure of the temperature-viscosity graph of Example 15 of this invention, and the comparative example 1 (Corning company # 7740).

The average linear expansion coefficient of the glass of the present invention can be preferably applied as various substrate materials, structural members, or transmission optical system materials that require thermal dimensional stability. ⁻⁷ ° C. ⁻¹ or less is preferable, 29 × 10 ⁻⁷ ° C. ⁻¹ or less is more preferable, and 28 × 10 ⁻⁷ ° C. ⁻¹ or less is most preferable. Moreover, the lower limit value of the average linear expansion coefficient at 0 ° C. to 300 ° C. can be obtained up to 15 × 10 ⁻⁷ ° C. ⁻¹ in the glass of the present invention.

  The glass transition point is preferably 600 ° C. or lower, more preferably 595 ° C. or lower, and most preferably 590 ° C. or lower because it can be preferably applied as various substrate materials and structural members that require hot working. Moreover, although a glass transition point is so preferable that it is low, in the glass of this invention, it can show a low value to 490 degreeC. Since the glass of the present invention has such a low glass transition point, it can be processed at a low temperature even in hot working such as reheat molding.

  The melting temperature of the glass raw material is preferably 1600 ° C. or less, more preferably 1580 ° C. or less, and most preferably 1560 ° C. or less in order to reduce the cost of glass production and facilitate glass refining. The melting temperature of the glass of the present invention can be as low as about 1450 ° C.

Each component which comprises the glass of this invention is demonstrated. Note that unless otherwise specified, in the present specification, the respective components are expressed in terms of mass% based on oxides.
Here, the “oxide standard” is contained in the glass on the assumption that oxides, nitrates, etc. used as raw materials of the constituent components of the glass of the present invention are all decomposed and changed into oxides when melted. This is a method of expressing the composition of each component, and the amount of each component contained in the glass is described with the total mass of the generated oxides being 100% by mass.

The glass of the present invention contains the SiO ₂ component, the B ₂ O ₃ component, the Al ₂ O ₃ component, and the Li ₂ O component in an oxide-based mass%, and the total amount of these components is 90% or more, The mass ratio of these components, Li ₂ O / Al ₂ O _3, is 0.9 or more.
By satisfying these conditions, a glass having a low average linear expansion coefficient while containing a relatively large amount of Li ₂ O component can be obtained.

When the total amount of the SiO ₂ component, B ₂ O ₃ component, Al ₂ O ₃ component and Li ₂ O component is less than 90%, a low average linear expansion coefficient cannot be obtained, so the total amount is 90% or more. Preferably, 92% or more is more preferable, and 94% or more is most preferable.

If the ratio Li ₂ O / Al ₂ O ₃ of the Li ₂ O component to the Al ₂ O ₃ component is less than 0.9, the melting temperature will be high. Therefore, the value of Li ₂ O / Al ₂ O ₃ is preferably 0.9 or more, more preferably 1.0 or more, and most preferably 1.1 or more. If this value exceeds 11, it is difficult to obtain a low average linear expansion coefficient, and devitrification is likely to occur during hot working. Therefore, the value of Li ₂ O / Al ₂ O ₃ is preferably 11 or less, and is preferably 10.5 or less. More preferred is 10 or less.

The SiO ₂ component is a component that forms a glass skeleton. If the content is less than 64%, it is difficult to obtain a desired average linear expansion coefficient, so the lower limit of the content of the SiO ₂ component should be 64% or more. Is preferable, more preferably 65% or more, and most preferably 66% or more.
Moreover, in order to lower the melting temperature of the glass of the present invention and make it easy to obtain low temperature meltability, the upper limit of the content of the SiO ₂ component is preferably 95% or less, and 93% or less. Is more preferable, and most preferably 90% or less.

B ₂ O ₃ component is also a component forming a glass skeleton like the SiO ₂ component, the content of this component is less than 2%, and is easy to become difficult to melt the glass material, the B ₂ O ₃ component The lower limit of the content is preferably 2% or more, more preferably 3% or more, and most preferably 4% or more.
Further, if the content of the B ₂ O ₃ component exceeds 35%, the average linear expansion coefficient of the glass increases and the phase separation tendency increases. Therefore, the upper limit of the content of the B ₂ O ₃ component is 35%. The content is preferably set to not more than 33%, more preferably not more than 33%, and most preferably not more than 30%.

The Al ₂ O ₃ component is a component that can form the glass skeleton of the present invention and suppresses phase separation. If the Al ₂ O ₃ component is less than 0.1%, the average linear expansion coefficient tends to increase, the phase separation tendency of the glass tends to increase, and devitrification easily occurs during hot forming. It is preferably 1% or more, more preferably 0.12% or more, and most preferably 0.13%.
On the other hand, when the content of the Al ₂ O ₃ component exceeds 10%, the melting temperature becomes high and the glass transition point becomes high, so that the hot workability tends to deteriorate. Therefore, the upper limit of the Al ₂ O ₃ component is preferably 10% or less, more preferably 9% or less, and most preferably 8% or less.

The Li ₂ O component is a component that contributes to lowering the glass transition point and lowering the melting temperature. Further, it is a component that behaves as mobile ions during anodic bonding and improves anodic bonding properties. When the content of the Li ₂ O component is less than 0.1%, it becomes difficult to obtain a low melting temperature and the anodic bondability is not good, so the lower limit of the Li ₂ O component is 0.1%. Is preferable, 0.15% is more preferable, and 0.2% is most preferable.
Further, if the content of the Li ₂ O component exceeds 10%, the average linear expansion coefficient tends to increase, and the glass tends to devitrify during hot forming, so the upper limit of the Li ₂ O component is preferably 10%. 9% is more preferable, and 8% is most preferable.

Each of the Na ₂ O component, K ₂ O, and Cs ₂ O is a component that facilitates lowering the glass transition point and lowering the melting temperature, and can be optionally added. However, since the average linear expansion coefficient tends to increase as the content increases and the electrical resistance increases during anodic bonding, the upper limit of the content is preferably 5% or less, more preferably 4.5% or less, respectively. Most preferably, it is 4% or less.

Further, if the total content of Li ₂ O component, Na ₂ O component, K ₂ O, Cs ₂ O component exceeds 17%, the average linear expansion coefficient tends to increase, and devitrification is likely to occur during hot molding, Since chemical durability tends to deteriorate, the total amount of these components is preferably 17% or less, more preferably 15% or less, and most preferably 14% or less.

When the K ₂ O component is contained, if the K ₂ O component is greater than the Li ₂ O component, the average linear expansion coefficient tends to increase. Therefore, the K ₂ O component is preferably equal to or less than the Li ₂ O component.

  The MgO component and the CaO component are components that can be optionally added to easily lower the melting temperature. However, as the content increases, the glass transition point increases and devitrification during hot forming increases, so the upper limit of the content is preferably 5% or less, more preferably 4% or less, most preferably Preferably it is 2% or less.

  The SrO component is a component that can be optionally added to easily lower the melting temperature. However, since the average linear expansion coefficient tends to increase when the addition amount is large, the upper limit of the content is preferably 5% or less, more preferably 4% or less, and most preferably 2% or less.

  The BaO component is a component that can be optionally added to easily suppress the phase separation of the glass and to lower the melting temperature. However, since the average linear expansion coefficient tends to increase when the addition amount is large, the upper limit of the content is preferably 5% or less, more preferably 4% or less, and most preferably 2% or less.

As ₂ O ₃ component and Sb ₂ O ₃ component are components that can be optionally added as a glass refining agent. However, since the clarification effect does not increase even when added in a large amount, the content of As ₂ O ₃ component and / or Sb ₂ O ₃ component is limited to 2%, preferably 1.3% or less, most preferably 1% or less. It is.

However, the As ₂ O ₃ component and the Sb ₂ O ₃ component have recently tended to be refrained from use in consideration of the influence on the human body and the environment. In this respect, it is preferable that these components are not contained as much as possible. In the glass of the present invention, a CeO ₂ component and / or a SnO ₂ component can be used as an alternative to the fining agent. Even if these components are added in a large amount in the same manner as the As ₂ O ₃ component and the Sb ₂ O ₃ component, the clarification effect does not increase, so the content of the CeO ₂ component and / or the SnO ₂ component is preferably 2%, and preferably Is 1.3% or less, most preferably 1% or less.

When a TiO ₂ component is added, the glass transition point (Tg) is significantly increased, making it difficult to obtain a desired Tg. Further, since it is a component that generates or accelerates crystallization when heat-treated, it is preferably not contained.

  Cl introduced from a chloride raw material and Br introduced from a bromide raw material are preferably not contained because volatile components not only have an adverse effect on the environment but also tend to cause inhomogeneity of internal quality.

  Since the PbO component requires measures for environmental measures when manufacturing, processing, and discarding the glass, and costs are required for this, PbO should not be contained in the glass of the present invention.

Furthermore, in the glass of the present invention, each component such as V, Cr, Mn, Fe, Co, Ni, Mo, Eu, Nd, Sm, Tb, Dy, and Er contributes little to the object of the present invention. In consideration of use as a transmission optical system material because it is colored, it is preferably not contained.
However, the term “not contained” means that it is not contained artificially unless it is mixed as an impurity.

Since the temperature at which the viscosity of the glass exhibits 10 ^3.0 dPa · s has a high correlation with the melting temperature, it can be used as an index indicating that the melting temperature is low. In the glass of the present invention, the temperature when the viscosity is 10 ^3.0 dPa · s is 1500 ° C. or less, and in a more preferred embodiment, 1490 ° C. or less, and in a most preferred embodiment, 1480 ° C. or less.

As a method for producing the glass of the present invention, a known melting method can be used. That is, silica sand, boric acid, aluminum oxide, lithium carbonate, sodium carbonate, potassium carbonate, cesium oxide, magnesium oxide, calcium oxide, strontium nitrate, and barium nitrate so that the glass of the present invention has a composition expressed on the oxide basis. A glass material made of arsenous acid, antimony pentoxide, tin oxide, cerium oxide or the like is filled in a crucible made of quartz, alumina, platinum, or the like. And it heat-melts in melting furnaces, such as an electric furnace and a gas furnace. In the glass of the present invention, the melting temperature of the glass raw material is 1600 ° C. or lower, the temperature at the time of heating and melting in the melting furnace is 1450 ° C. to 1600 ° C., and in a preferred embodiment, the glass raw material is melted at a temperature of 1450 ° C. to 1550 ° C. it can.
After melting, clarification and stirring are performed as necessary to homogenize the glass, and then the molten glass is poured into a mold and rapidly cooled to form and slowly cool in a slow cooling furnace.

  The glass taken out from the slow cooling furnace can be cut, ground, and polished as necessary to obtain various substrate materials, structural members, transmission optical system materials, and the like.

  It is also possible to process the glass taken out from the slow cooling furnace into a powder form, shape a green sheet together with ceramic powder such as alumina or cordierite, and sinter.

  Examples of the present invention will be described. A glass raw material batch composed of silica sand, boric acid, aluminum oxide, lithium carbonate, sodium carbonate, potassium carbonate, and arsenous acid was prepared so that the composition ratio of glass was expressed on the oxide basis as shown in Table 1. The batch was filled in an alumina or quartz crucible and heated and melted in an electric furnace at 1400 to 1500 ° C. for 6 hours. The molten glass was molded into a plate shape and slowly cooled.

Tables 1 to 5 show glass compositions, glass transition points (Tg), and average linear expansion coefficients (α0 to 50 ° C.) expressed in terms of mass% based on oxides in Examples and Reference Examples of the present invention. ), Average linear expansion coefficient (α0 to 300) at 0 ° C. to 50 ° C., specific gravity, temperature at which the viscosity of the glass exhibits 10 ^3.0 dPa · s (T at 1E3 dPa · s), 80% transmittance A wavelength indicating λ (λ80%) and a wavelength indicating transmittance of 5% (λ5%) are shown.
Moreover, the temperature-viscosity graph of Example 15 of this invention and the comparative example 1 is shown in FIG.

In addition, the measurement of the temperature when the viscosity of the glass shows 10 ^3.0 dPa · s can be measured using a ball pulling-up type viscometer, for example, using a BVM-13LH manufactured by Opto Corporation. be able to.
The average linear expansion coefficient is in accordance with JOGIS (Japan Optical Glass Industry Association Standard) 16-2003 “Measuring Method of Average Linear Expansion Coefficient of Optical Glass Near Room Temperature”, and the temperature range is 0 ° C. to 50 ° C. and 0 ° C. to 300 ° C. The value measured in the range of ° C.
The glass transition point is a value measured by JOGIS08-2003 “Measurement method of thermal expansion of optical glass”.

About the transmittance | permeability measurement, it carried out according to JOGIS02-2003. In the present invention, not a coloring degree but a wavelength showing a transmittance of 80% (λ80%) and a wavelength showing a transmittance of 5% (λ5%) in a glass having a thickness of 10 mm. Specifically, a face parallel polished product having a thickness of 10 ± 0.1 mm is measured for a spectral transmittance of 200 to 800 nm according to JISZ8722, and a wavelength (λ80%) at a transmittance of 80% and a transmittance of 5% are measured. Was obtained (λ5%).

Next, in order to evaluate the devitrification property during hot forming of the glass of the present invention, the glass of Example 15 was processed into blocks of about 20 × 20 × 10 mm size, and the glass of the present invention had a viscosity log η = 7. The temperature of the electric furnace was set to 890 ° C., which is a temperature showing 5, and after reaching the temperature, the glass was put into the electric furnace, kept at 890 ° C. for 1 hr, and heat-treated.
When the glass after the heat treatment was observed, devitrification did not occur, and when the change in the transmittance before and after the heat treatment was investigated, no change was found in the transmittance.

Claims (6)

% By mass based on oxide,
SiO ₂ 76.02 % to 95%
B ₂ O ₃ 2% to 16.77%
Al ₂ O ₃ 0.14% to 1.00%
Li ₂ O 1.3% to 3.00%
Na ₂ O 0~5%,
K ₂ O 0-5%,
Cs ₂ O 0~5%,
MgO 0-5%,
CaO 0-5%,
SrO 0-5%,
BaO 0-5%,
Each component of,
The total amount of SiO ₂ component, B ₂ O ₃ component, Al ₂ O ₃ component and Li ₂ O component is 90% or more,
The mass% ratio Li ₂ O / Al ₂ O _{3 of} these components is 3.00 or more and 9.67 or less,
Glass whose average linear expansion coefficient in 0-300 degreeC is 30 * 10 < ^-7 > degreeC- ¹ or less. The glass according to claim 1, wherein the total amount of Na ₂ O component, Li ₂ O component, K ₂ O component, and Cs ₂ O component is 17% or less in terms of mass% based on oxide. _3. The glass according to claim 1, comprising 0% to ₂ % of an As ₂ O ₃ component and / or an Sb ₂ O ₃ component by mass% based on an oxide. Glass according to claim 1 containing 2% 0% CeO ₂ component and / or the SnO ₂ component in terms of% by mass on the oxide basis. A glass transition point is 600 ° C or less, Glass in any one of Claims 1-4. The glass according to any one of claims 1 to 5, wherein the temperature when the viscosity is 10 ^3.0 dPa · s is 1500 ° C or lower.