JP2023008800A - Glass substrate with sealing material layer and method of manufacturing airtight package - Google Patents

Abstract

To provide a glass substrate capable of maintaining high airtightness and a method of manufacturing an airtight package.SOLUTION: A glass substrate with a sealing material layer is characterized in that the glass substrate which has the sealing material layer formed on the glass substrate has a mean transmittance of 85% or larger at a glass substrate thickness of 0.2 mm and 250 nm to less than 300 nm and a difference in thermal expansion coefficient of 5 ppm/°C or less between the sealing material layer and glass substrate within a temperature range of 30 to 300°C.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a glass substrate with a sealing material layer and a method for manufacturing an airtight package.

Airtight packages containing electronic elements such as ultraviolet LEDs have come to be used in various fields such as lighting and communication for reasons such as long life and energy saving.

In this type of hermetic package, in order to protect the electronic element, the package base on which the electronic element is mounted is sometimes covered with a glass substrate (glass lid) so that the electronic element is housed inside.

For example, Patent Document 1 discloses an airtight package including a package base on which an electronic element is mounted, a frame surrounding the electronic element, and a lid made of a glass substrate covering one end opening of the frame. ing. Patent document 2 also discloses an airtight package in which a package substrate is provided with a recess for housing an electronic element, and a lid made of a glass substrate covers the recess.

WO2015/190242 JP 2016-027610 A

By the way, quartz has the property of being difficult to absorb light with wavelengths in the ultraviolet region. For this reason, when the airtight package is an ultraviolet LED package, a quartz substrate is sometimes used for the lid from the viewpoint of increasing the ultraviolet transmittance.

However, when trying to join a quartz substrate to a frame or a package base using a general brazing metal (for example, gold-tin solder), matching of thermal expansion coefficients between materials becomes a problem. In other words, the thermal expansion coefficient of the quartz substrate (approximately 0.6 ppm) is much lower than the thermal expansion coefficient of general brazing metal (approximately 12.0 ppm), and the thermal expansion coefficient difference between materials is large. As a result, residual stress is generated at or near the junction, and the quartz substrate is likely to be damaged (for example, cracks). If the quartz substrate is damaged in this manner, the airtightness of the housing space of the airtight package cannot be maintained.

An object of the present invention is to provide a method for manufacturing a glass substrate and an airtight package that can maintain high airtightness.

As a result of intensive studies, the present inventors have solved the above problems by forming a sealing material layer on a glass substrate having a high ultraviolet transmittance and reducing the difference in thermal expansion coefficient between the glass substrate and the sealing material layer. We have found that it is possible to obtain it, and propose it as the present invention. That is, the glass substrate with a sealing material layer of the present invention is a glass substrate with a sealing material layer in which a sealing material layer is formed on a glass substrate. is 85% or more, and the difference in thermal expansion coefficient between the sealing material layer and the glass substrate in the temperature range of 30 to 300° C. is 5 ppm/° C. or less. "Average transmittance at a thickness of 0.2 mm and 250 nm or more and less than 300 nm" means that when the thickness of the glass substrate is other than 0.2 mm, the average transmittance is calculated by converting the thickness to 0.2 mm.

Further, in the glass substrate with a sealing material layer of the present invention, the ratio of the area where the sealing material layer is formed on the surface of the glass substrate on which the sealing material layer is formed is 1 to 50%. preferable.

Further, in the glass substrate with a sealing material layer of the present invention, the sealing material layer preferably has a plurality of sealing patterns, and the sealing pattern preferably has a closed loop shape. In this way, since an airtight package can be formed for each sealing pattern, a group of airtight packages (aggregate of a plurality of airtight packages) can be formed using a single glass substrate with a sealing material layer by a series of laser sealing. can be made. By dividing and cutting this hermetic package group, it becomes possible to easily produce a large number of hermetic packages. In addition, the "closed loop shape" includes not only a shape composed only of curved lines, but also a shape composed of a combination of curved lines and straight lines, and a shape composed only of straight lines (for example, rectangular shape and other polygonal shapes). .

Further, in the glass substrate with a sealing material layer of the present invention, the sealing material layer is a sintered body of composite powder containing at least bismuth-based glass powder and ceramic powder, and the content of bismuth-based glass in the sealing material layer is is preferably 65 to 95% by volume, and the ceramic content is preferably 5 to 35% by volume.

In the glass substrate with a sealing material layer of the present invention, the sealing material layer preferably does not substantially contain a laser absorber. Here, "the sealing material layer does not substantially contain a laser absorbing agent" refers to the case where the content of the laser absorbing material in the sealing material layer is less than 1% by volume.

Further, in the glass substrate with a sealing material layer of the present invention, the average thickness of the sealing material layer is 15 μm or less, and the value obtained by dividing the average thickness of the sealing material layer by the thickness of the glass substrate is 0.005 to 0.05 μm. 5 is preferred.

Further, in the glass substrate with a sealing material layer of the present invention, the average width of the sealing material layer is 1000 μm or less, and the value obtained by dividing the average thickness of the sealing material layer by the average width of the sealing material layer is 0.005. ~0.1 is preferred.

Further, the glass substrate with the sealing material layer of the present invention preferably has a rectangular shape, a circular shape, or a circular shape with an orientation flat.

An antireflection film is preferably formed on either surface of the glass substrate. In this way, reflection losses are reduced and the light extraction efficiency of the LED device is improved.

Further, the glass substrate with a sealing material layer of the present invention is preferably used for sealing by laser light. By doing so, it becomes easier to prevent thermal deterioration of the electronic element at the time of sealing.

The method for manufacturing an airtight package according to the present invention comprises steps of preparing a package base, steps of preparing a glass substrate with a sealing material layer having a plurality of sealing patterns, and sealing with the package base through the sealing material layer. A process of laminating and arranging a glass substrate with a bonding material layer, and irradiating a laser beam from the glass substrate side to soften and deform the sealing material layer, thereby hermetically bonding the glass substrate and the package substrate to form an airtight package group. and dividing the airtight package group to obtain a plurality of airtight packages, wherein the glass substrate with the sealing material layer is the glass substrate with the sealing material layer described above. .

The airtight package of the present invention is an airtight package in which a glass substrate and a package base are airtightly integrated by a sealing material layer, and the glass substrate has a thickness of 0.2 mm and an average transmittance of 85% or more at 250 nm or more and less than 300 nm. The difference in thermal expansion coefficient between the sealing material layer and the glass substrate in a temperature range of 30 to 300° C. is 5 ppm/° C. or less.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the glass substrate with a sealing material layer which can maintain high airtightness, and an airtight package can be provided.

It is a cross-sectional schematic diagram showing an example of the airtight package of the present invention. 4 is a photograph showing a glass substrate with a sealing material layer in Example 2. FIG.

In the glass substrate with a sealing material layer of the present invention, the glass substrate has a thickness of 0.2 mm and an average transmittance of 85% or more, preferably 86% or more, 87% or more, 88% or more, and 89% or more at 250 nm or more and less than 300 nm. , 90% or more, 91% or more, in particular 92% or more. If the glass substrate has a thickness of 0.2 mm and an average transmittance of 250 nm or more and less than 300 nm is too low, it will be difficult for ultraviolet light to pass therethrough, making it difficult to apply to hermetic packages such as ultraviolet LED packages.

The glass substrate has a thickness of 0.2 mm and an average transmittance of 300 nm or more and less than 1000 nm. . If the glass substrate has a thickness of 0.2 mm and an average transmittance of 300 nm or more and less than 1000 nm, it becomes difficult for visible light to pass therethrough, making it difficult to apply to an airtight package such as an LED package.

The difference in thermal expansion coefficient between the sealing material layer and the glass substrate in the temperature range of 30 to 300° C. is 5 ppm/° C. or less, preferably 4 ppm/° C. or less, 3.5 ppm/° C. or less, 3.2 ppm/° C. or less, especially 3 ppm/°C or less. If the difference in thermal expansion coefficient in the temperature range of 30 to 300° C. between the sealing material layer and the glass substrate is too large, residual stress is generated at or near the joint after sealing, and the glass substrate is damaged (e.g., cracked). cracks) are likely to occur. If the glass substrate is damaged, the airtightness of the housing space of the airtight package may deteriorate.

The thermal expansion coefficient of the glass substrate in the temperature range of 30 to 300° C. is preferably 11 ppm/° C. or less, 10 ppm/° C. or less, 9 ppm/° C. or less, 8 ppm/° C. or less, 7 ppm/° C. or less, 6 ppm/° C. or less, particularly 3 ppm/° C. /°C to 5 ppm/°C. In particular, when the package substrate is silicon, the thermal expansion coefficient of the glass substrate in the temperature range of 30 to 300° C. is preferably 10 ppm/° C. or less, 9 ppm/° C. or less, 8 ppm/° C. or less, 7 ppm/° C. or less, 6 ppm/° C. or less. °C or less, especially between 3 ppm/°C and 5 ppm/°C. If the coefficient of thermal expansion of the glass substrate is too low, residual stress is generated in or near the joint after sealing, and the glass substrate is likely to break (for example, breakage such as cracks). If the glass substrate is damaged, the airtightness of the housing space of the airtight package may deteriorate.

The glass substrate has a glass composition of SiO ₂ 50 to 80%, Al ₂ O ₃ +B ₂ O ₃ (total amount of Al ₂ O ₃ and B ₂ O ₃ ) 1 to 45%, and Li ₂ O + Na ₂ in mass %. O+K ₂ O (total amount of Li ₂ O, Na ₂ O and K ₂ O) 0 to 25%, MgO+CaO+SrO+BaO (total amount of MgO, CaO, SrO and BaO) preferably 0 to 25%. The reasons for limiting the content of each component as described above are as follows. In addition, in description of content of each component, % display represents the mass % except when there is particular notice.

_SiO2 is the main component that forms the skeleton of glass. The content of SiO ₂ is preferably 50-80%, 55-75%, 58-70%, especially 60-68%. If the content of _SiO2 is too small, Young's modulus and acid resistance tend to decrease. On the other hand, if the content of SiO ₂ is too high, the viscosity at high temperatures tends to increase, and meltability tends to decrease. Become.

Al ₂ O ₃ and B ₂ O ₃ are components that improve devitrification resistance. The content of Al ₂ O ₃ +B ₂ O ₃ is preferably 1-40%, 5-35%, 10-30%, especially 15-25%. If the content of Al ₂ O ₃ +B ₂ O ₃ is too small, the glass tends to devitrify. On the other hand, if the content of Al ₂ O ₃ +B ₂ O ₃ is too large, the component balance of the glass composition is lost, and the glass tends to devitrify.

Al ₂ O ₃ is a component that increases Young's modulus and suppresses phase separation and devitrification. The content of Al ₂ O ₃ is preferably 0-20%, 1-20%, 3-18%, especially 5-16%. If the content of Al ₂ O ₃ is too small, the Young's modulus tends to decrease, and the glass tends to undergo phase separation and devitrification. On the other hand, if the content of Al ₂ O ₃ is too high, the high-temperature viscosity increases and the meltability tends to decrease.

B ₂ O ₃ is a component that enhances meltability and resistance to devitrification, and is a component that improves the susceptibility to scratches and enhances strength. The content of B ₂ O ₃ is preferably 0-25%, 1-25%, 2-25%, 3-25%, 5-22%, 7-19%, especially 9-16%. If the content of B ₂ O ₃ is too small, the meltability and devitrification resistance tend to deteriorate, and the resistance to hydrofluoric acid-based chemicals tends to deteriorate. On the other hand, if the content of B ₂ O ₃ is too large, Young's modulus and acid resistance tend to decrease.

Li ₂ O, Na ₂ O and K ₂ O are components that lower the high-temperature viscosity, remarkably improve the meltability, and contribute to the initial melting of the glass raw material. The content of Li ₂ O+Na ₂ O+K ₂ O is preferably 0-25%, 1-20%, 4-15%, especially 7-13%. If the content of Li ₂ O+Na ₂ O+K ₂ O is too small, the meltability tends to deteriorate. On the other hand, if the content of Li ₂ O+Na ₂ O+K ₂ O is too high, the coefficient of thermal expansion may become unduly high.

Li ₂ O is a component that lowers the high-temperature viscosity, remarkably increases the meltability, and contributes to the initial melting of the glass raw material. The content of Li ₂ O is preferably 0-5%, 0-3%, 0-1%, especially 0-0.1%. If the content of Li ₂ O is too small, the meltability tends to decrease, and the coefficient of thermal expansion may unduly decrease. On the other hand, when the content of Li ₂ O is too large, the glass tends to undergo phase separation.

Na ₂ O is a component that lowers the high-temperature viscosity, remarkably increases the meltability, and contributes to the initial melting of the glass raw material. It is also a component for adjusting the coefficient of thermal expansion. The content of Na ₂ O is preferably 0-25%, 1-20%, 3-18%, 5-15%, especially 7-13%. If the content of Na ₂ O is too small, the meltability tends to deteriorate, and the coefficient of thermal expansion may unduly decrease. On the other hand, if the content of Na ₂ O is too high, the coefficient of thermal expansion may become unduly high.

K ₂ O is a component that lowers the high-temperature viscosity, remarkably increases the meltability, and contributes to the initial melting of the glass raw material. It is also a component for adjusting the coefficient of thermal expansion. The content of K ₂ O is preferably 0-15%, 0.1-10%, 1-10%, especially 3-5%. If the K ₂ O content is too high, the coefficient of thermal expansion may become unduly high.

MgO, CaO, SrO and BaO are components that lower high-temperature viscosity and improve meltability. The content of MgO+CaO+SrO+BaO is preferably 0-25%, 0-15%, 0.1-12%, 1-5%. If the content of MgO+CaO+SrO+BaO is too high, the glass tends to devitrify.

MgO is a component that lowers high-temperature viscosity and increases meltability, and among alkaline earth metal oxides, it is a component that remarkably increases Young's modulus. The content of MgO is preferably 0-10%, 0-8%, 0-5%, especially 0-1%. If the content of MgO is too high, the devitrification resistance tends to decrease.

CaO is a component that lowers high-temperature viscosity and remarkably enhances meltability. In addition, among the alkaline earth metal oxides, since the raw material to be introduced is relatively inexpensive, it is a component that reduces the raw material cost. The content of CaO is preferably 0-15%, 0.1-12%, 0.5-10%, especially 1-5%. If the CaO content is too high, the glass tends to devitrify. In addition, when the content of CaO is too small, it becomes difficult to receive the above effects.

SrO is a component that enhances devitrification resistance. The content of SrO is preferably 0-7%, 0-5%, 0-3%, especially 0-1%. If the SrO content is too high, the component balance of the glass composition is lost, and the glass tends to devitrify.

BaO is a component that enhances devitrification resistance. The content of BaO is preferably 0-10%, 0-7%, 0-5%, 0-3%, 0-1%. If the BaO content is too high, the component balance of the glass composition is lost, and the glass tends to devitrify.

In addition to the above components, other components may be introduced as optional components. From the viewpoint of accurately receiving the effects of the present invention, the total content of other components other than the above components is preferably 10% or less, 5% or less, and particularly 3% or less.

ZnO is a component that enhances meltability, but if contained in a large amount in the glass composition, the glass tends to devitrify. Thus, the content of ZnO is preferably 0-5%, 0-3%, 0-1%, 0-1%, especially 0-0.1%.

ZrO ₂ is a component that enhances acid resistance, but if it is contained in a large amount in the glass composition, the glass tends to devitrify. Thus, the content of ZrO ₂ is preferably 0-5%, 0-3%, 0-1%, 0-0.5%, especially 0.001-0.2%.

Fe ₂ O ₃ and TiO ₂ are components that reduce transmittance in the deep ultraviolet region. The content of Fe ₂ O ₃ +TiO ₂ (the total amount of Fe ₂ O ₃ and TiO ₂ ) is preferably 100 ppm or less, 80 ppm or less, 0.1-60 ppm, 0.3-40 ppm, 0.5-30 ppm, 0.5-30 ppm, 0 .8-20 ppm, 1-10 ppm, especially 2-5 ppm. If the content of Fe ₂ O ₃ +TiO ₂ is too high, the glass will be colored and the transmittance in the deep ultraviolet region will tend to decrease. If the content of Fe ₂ O ₃ +TiO ₂ is too small, high-purity glass raw materials must be used, resulting in an increase in batch cost.

Fe ₂ O ₃ is a component that reduces transmittance in the deep ultraviolet region. The content of Fe ₂ O ₃ is preferably 100 ppm or less, 80 ppm or less, 0.05-60 ppm, 0.1-40 ppm, 0.5-20 ppm, 1-10 ppm, especially 2-8 ppm. If the content of Fe ₂ O ₃ is too high, the glass will be colored, and the transmittance in the deep ultraviolet region will tend to decrease. If the content of Fe ₂ O ₃ is too low, a high-purity glass raw material must be used, resulting in an increase in batch cost.

Fe ions in iron oxide exist in the form of Fe ²⁺ or Fe ³⁺ . If the proportion of Fe ²⁺ is too small, the transmittance in deep ultraviolet rays tends to decrease. Therefore, the mass ratio of Fe ²⁺ /(Fe ²⁺ +Fe ³⁺ ) in iron oxide is preferably 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, particularly 0.5 or more.

TiO ₂ is a component that reduces the transmittance in the deep UV region. The content of TiO ₂ is preferably 100 ppm or less, 80 ppm or less, 60 ppm or less, 40 ppm or less, 0.05-20 ppm, 0.1-10 ppm, in particular 0.5-5 ppm. If the content of TiO ₂ is too high, the glass tends to be colored and the transmittance in the deep ultraviolet region tends to decrease. If the content of TiO ₂ is too low, a high-purity glass raw material must be used, resulting in an increase in batch cost.

Sb ₂ O ₃ is a component that acts as a refining agent. The content of Sb ₂ O ₃ is preferably 1000 ppm or less, 800 ppm or less, 600 ppm or less, 400 ppm or less, 200 ppm or less, 100 ppm or less, especially less than 50 ppm. If the Sb ₂ O ₃ content is too high, the transmittance in the deep ultraviolet region tends to decrease.

_SnO2 is a component that acts as a refining agent. The content of SnO ₂ is preferably ≤2000 ppm, ≤1700 ppm, ≤1400 ppm, ≤1100 ppm, ≤800 ppm, ≤500 ppm, ≤200 ppm, especially ≤100 ppm. If the SnO ₂ content is too high, the transmittance in the deep ultraviolet region tends to decrease.

F2 _{, Cl2} and SO3 _are components that act as fining agents. The content of F ₂ +Cl ₂ +SO ₃ is preferably 10-10000 ppm. A preferred lower limit range of F ₂ +Cl ₂ +SO ₃ is 10 ppm or more, 20 ppm or more, 50 ppm or more, 100 ppm or more, 300 ppm or more, especially 500 ppm or more, and a suitable upper limit range is 3000 ppm or less, 2000 ppm or less, 1000 ppm or less, especially 800 ppm or less. is. Further, each of F ₂ , Cl ₂ and SO ₃ preferably has a lower limit range of 10 ppm or more, 20 ppm or more, 50 ppm or more, 100 ppm or more, 300 ppm or more, particularly 500 ppm or more, and a preferable upper limit range of 3000 ppm or less and 2000 ppm or less. It is 1000 ppm or less, especially 800 ppm or less. If the content of these components is too small, it will be difficult to exhibit the refining effect. On the other hand, if the content of these components is too high, there is a risk that the fining gas will remain in the glass as bubbles.

The size of the glass substrate is preferably 600 mm ² or more, 5000 mm ² or more, particularly 15000 mm ² or more. The larger the size, the more hermetic packages can be obtained from a single glass substrate, making it easier to reduce the manufacturing cost of the hermetic packages.

The plate thickness of the glass substrate is preferably 2.0 mm or less, 1.5 mm or less, or 1.0 mm or less, particularly 0.1 to 0.5 mm. If the plate thickness is too large, the mass of the glass substrate increases, making it difficult to handle the glass substrate, and the transmittance in the deep ultraviolet region tends to decrease. On the other hand, if the plate thickness is too small, it becomes difficult for the glass substrate to maintain its rigidity on the transfer line, and the glass substrate is likely to be deformed, warped, or damaged.

The surface roughness Ra of the surface of the glass substrate is preferably 10 nm or less, 9 nm or less, 8 nm or less, 7 nm or less, 6 nm or less, 5 nm or less, 4 nm or less, 3 nm or less, 2 nm or less, and particularly 1 nm or less. If the surface roughness Ra of the surface is too large, the transmittance of the deep ultraviolet rays tends to decrease. Here, "Ra" is arithmetic mean roughness defined in JIS B0601-1994.

Preferably, the glass substrate is either rectangular, circular, or circular with orientation flats. With such a shape, it is easy to form a plurality of sealing patterns on the surface of the glass substrate. Especially, if it is circular or circular with an orientation flat, laser sealing can be performed using a semiconductor manufacturing apparatus. It is preferable because

A functional film may be formed on the surface of the glass substrate, and an antireflection film is particularly preferable as the functional film. Thereby, the light reflected on the surface of the glass substrate can be reduced.

In the glass substrate with a sealing material layer of the present invention, the sealing material layer is obtained by sintering a sealing material. The sealing material is generally a composite powder containing glass powder and ceramic powder. Various glass powders can be used as the glass powder. For example, Bi ₂ O ₃ -based glass, V ₂ O ₅ -based glass, and SnO-based glass are preferable in terms of low melting point characteristics, and Bi ₂ O ₃ -based glass is particularly preferable in terms of thermal stability and water resistance. Here, the term "--based glass" refers to a glass containing specified components as essential components and having a total amount of specified components of 25 mol% or more, preferably 30 mol% or more, more preferably 35 mol% or more. point to From an environmental point of view, the glass powder preferably does not substantially contain PbO (less than 0.1 mol %) in the glass composition.

The Bi ₂ O ₃ -based glass preferably contains 28 to 60% Bi ₂ O ₃ , 15 to 37% B ₂ O ₃ , and 1 to 30% ZnO in mol % as the glass composition. The reason why the content range of each component is limited as described above will be explained below. In addition, in description of a glass composition range, % display points out mol%.

Bi ₂ O ₃ is a main component for lowering the softening point, and its content is preferably 28-60%, 33-55%, particularly 35-45%. If the content of Bi ₂ O ₃ is too small, the softening point becomes too high and the fluidity tends to decrease. On the other hand, if the Bi ₂ O ₃ content is too high, the glass tends to devitrify during firing, and this devitrification tends to reduce fluidity.

B ₂ O ₃ is an essential component as a glass-forming component, and its content is preferably 15 to 37%, 20 to 33%, particularly 25 to 30%. If the content of B ₂ O ₃ is too small, it becomes difficult to form a glass network, and the glass tends to devitrify during firing. On the other hand, if the content of B ₂ O ₃ is too high, the viscosity of the glass increases, and the fluidity tends to decrease.

ZnO is a component that enhances resistance to devitrification, and its content is preferably 1 to 30%, 3 to 25%, 5 to 22%, particularly 9 to 20%. If the content is less than 1% or more than 30%, the component balance of the glass composition is lost, and devitrification resistance tends to decrease.

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

SiO ₂ is a component that increases water resistance, but it also has the effect of raising the softening point. Therefore, the content of SiO ₂ is preferably 0-5%, 0-3%, 0-2%, particularly 0-1%. Also, if the content of SiO ₂ is too high, the glass tends to devitrify during firing.

Al ₂ O ₃ is a component that increases water resistance, and its content is preferably 0 to 10%, 0 to 5%, particularly 0.1 to 2%. If the content of Al ₂ O ₃ is too high, the softening point may increase unduly.

Li ₂ O, Na ₂ O and K ₂ O are components that reduce devitrification resistance. The content of Li ₂ O, Na ₂ O and K ₂ O is thus respectively 0-5%, 0-3% and in particular 0-1%.

MgO, CaO, SrO and BaO are components that increase devitrification resistance, but also components that increase the softening point. The contents of MgO, CaO, SrO and BaO are thus respectively 0-20%, 0-10% and especially 0-5%.

In order to _lower the softening point of the Bi ₂ O ₃ -based glass _, it is necessary to introduce a large amount of Bi ₂ O ₃ into the glass composition. It becomes easy to permeate, and the fluidity tends to decrease due to this devitrification. In particular, when the content of Bi ₂ O ₃ is 30% or more, this tendency becomes remarkable. As a countermeasure against this, if CuO and MnO are added, devitrification of the glass can be effectively suppressed even if the content of Bi ₂ O ₃ is 30% or more. Furthermore, if CuO is added, the laser absorption characteristics during laser sealing can be enhanced. The individual contents of CuO and MnO ₂ are preferably 0-40%, 5-35%, 10-30%, especially 15-25%. If the contents of CuO and MnO ₂ are too large, the component balance of the glass composition is lost, and the devitrification resistance tends to decrease.

Fe ₂ O ₃ is a component that enhances devitrification resistance and laser absorption characteristics, and its content is preferably 0 to 10%, 0.1 to 5%, particularly 0.5 to 3%. If the content of Fe ₂ O ₃ is too large, the component balance of the glass composition is disturbed, and the devitrification resistance tends to decrease.

Sb ₂ O ₃ is a component that increases devitrification resistance, and its content is preferably 0 to 5%, particularly 0 to 2%. If the content of Sb ₂ O ₃ is too large, the component balance of the glass composition is disturbed, and the devitrification resistance tends to decrease.

The average particle diameter D ₅₀ of the glass powder is preferably less than 15 μm, preferably 0.5-10 μm, especially 1-5 μm. The softening point of the glass powder decreases as the average particle diameter _D50 of the glass powder decreases.

The content of ceramic powder in the sealing material is preferably 5-35% by volume, 10-33% by volume, 15-30% by volume, especially 20-30% by volume. The content of glass powder in the sealing material is preferably 65-95% by volume, 67-90% by volume, 70-85% by volume, especially 70-80% by volume. If the content of the ceramic powder is too high, the content of the glass powder becomes relatively low, making it difficult to ensure desired fluidity and thermal stability. If the content of the ceramic powder is too small, the effect of adding the ceramic powder will be poor.

As the ceramic powder, one or two or more selected from β-eucryptite, cordierite, zircon, alumina, mullite, willemite, zirconium phosphate, zirconium phosphate tungstate, zirconium tungstate, etc. are preferable, especially thermal expansion β-eucryptite, which is highly effective in lowering the modulus, is particularly preferred.

In addition to glass powder and ceramic powder, other powder materials may be introduced into the sealing material. Also, glass beads, spacers, and the like may be introduced. Here, the glass beads and spacers are made of a composition and material with high heat resistance so that the shape can be maintained even after sealing. In addition, in order to enhance laser absorption characteristics, 1 to 15% by volume of laser absorbers such as Mn--Fe--Al oxides, carbon, and Mn--Fe--Cr oxides may be contained. Considering the thermal stability of , it is preferred that the laser absorber is not substantially contained.

The sealing material may be used in a powdered state, but it is preferable to knead it uniformly with the vehicle and make it into a paste, which facilitates handling. A vehicle typically includes a solvent and a resin. Resin is added for the purpose of adjusting the viscosity of the paste. Moreover, a surfactant, a thickening agent, etc. can also be added as needed. The prepared paste is applied to the surface of the glass substrate using a dispenser, a screen printer, or other applicator.

Usable resins include acrylic acid ester (acrylic resin), ethyl cellulose, polyethylene glycol derivatives, nitrocellulose, polymethylstyrene, polyethylene carbonate, methacrylic acid ester, and the like. In particular, acrylic acid esters and nitrocellulose are preferable because of their good thermal decomposability.

Solvents include N,N'-dimethylformamide (DMF), α-terpineol, higher alcohols, γ-butyl lactone (γ-BL), tetralin, butyl carbitol acetate, ethyl acetate, isoamyl acetate, diethylene glycol monoethyl ether, Diethylene glycol monoethyl ether acetate, benzyl alcohol, toluene, 3-methoxy-3-methylbutanol, water, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether , tripropylene glycol monobutyl ether, propylene carbonate, dimethylsulfoxide (DMSO), N-methyl-2-pyrrolidone and the like can be used. In particular, α-terpineol is preferred because it has high viscosity and good solubility in resins and the like.

The coefficient of thermal expansion of the sealing material layer in the temperature range of 30 to 300°C is preferably 50ppm/°C to 90ppm/°C, 55ppm/°C to 80ppm/°C, especially 60ppm/°C to 75ppm/°C. In particular, when the package substrate is silicon, the thermal expansion coefficient of the sealing material layer in the temperature range of 30 to 300°C is preferably 60ppm/°C to 80ppm/°C, 65ppm/°C to 75ppm/°C, especially 68ppm/°C. ~73 ppm/°C. If the coefficient of thermal expansion of the sealing material layer is too high, residual stress is generated in or near the joint after sealing, and the glass substrate is likely to break (for example, breakage such as cracks). If the glass substrate is damaged, the airtightness of the housing space of the airtight package may deteriorate. On the other hand, if the coefficient of thermal expansion of the sealing material layer is too low, the proportion of the refractory filler increases, so that the softening and fluidity of the sealing material is reduced, and the hermetic package is likely to suffer airtightness defects.

The thermal expansion coefficient of the package substrate in the temperature range of 30 to 300°C is preferably 10 ppm/°C or more, 20 ppm/°C or more, particularly 30 ppm/°C to 60 ppm/°C. If the coefficient of thermal expansion of the package substrate is too low, residual stress is generated in or near the joints after sealing, and the hermetic package tends to suffer airtightness failures.

When the average thickness of the sealing material layer is 15 μm or less, the difference in thermal expansion coefficient between the glass substrate and the package substrate in the temperature range of 30 to 300° C. is preferably 6.5 ppm/° C. or less, 4.5 ppm/° C. or less, It is 3.5 ppm/°C or less, 2.0 ppm/°C or less, particularly 1.0 ppm/°C or less. When the average thickness of the sealing material layer is 15 μm or less, if the difference in thermal expansion coefficient between the glass substrate and the package substrate in the temperature range of 30 to 300° C. is too large, residual stress may occur at or near the joint after sealing. occurs, and the glass substrate is likely to be damaged (for example, fracture such as crack). If the glass substrate is damaged, the airtightness of the housing space of the airtight package may deteriorate.

The difference in thermal expansion coefficient between the sealing material layer and the package substrate in the temperature range of 30 to 300°C is preferably 5.5 ppm/°C or less, 4.0 ppm/°C or less, particularly 3.5 ppm/°C or less. If the difference in thermal expansion coefficient between the sealing material layer and the package substrate in the temperature range of 30 to 300° C. is too large, residual stress is generated at or near the joint after sealing, resulting in poor airtightness of the airtight package. becomes easier.

The package base preferably has a recess that can accommodate the electronic element. By doing so, it becomes easier to accommodate an electronic element such as a sensor element in the concave portion of the package base. The recess of the package base is preferably formed like a frame along the outer edge region of the package base. In this way, the effective area functioning as a device can be expanded. In addition, it becomes easy to accommodate the electronic element in the space inside the package base, and to perform wiring connection and the like.

The package substrate is preferably made of metal such as silicon, glass ceramic, aluminum nitride, aluminum oxide, or a composite material thereof (for example, aluminum nitride integrated with glass ceramic). In particular, silicon is preferable because it has good heat dissipation properties and is easy to form concave portions by etching or the like.

The average thickness of the sealing material layer is preferably 15 μm or less and less than 8.0 μm, especially 1.0 μm or more and less than 7.0 μm. The value obtained by dividing the average thickness of the sealing material layer by the average width of the sealing material layer is preferably 0.005 to 0.1, particularly 0.01 to 0.05. The value obtained by dividing the average thickness of the sealing material layer by the thickness of the glass substrate is preferably 0.005 to 0.5, particularly 0.01 to 0.1. If the average thickness of the sealing material layer, the value obtained by dividing the average thickness of the sealing material layer by the average width of the sealing material layer, or the value obtained by dividing the average thickness of the sealing material layer by the thickness of the glass substrate is outside the above range. , the accuracy of laser sealing tends to decrease. On the other hand, when these values are within the above ranges, the stress remaining in the sealing portion after laser sealing can be reduced when the thermal expansion coefficients of the sealing material layer and the glass substrate are mismatched. As a method for regulating the average thickness of the sealing material layer as described above, there are a method of thinly applying the sealing material paste and a method of polishing the surface of the sealing material layer.

The average width of the sealing material layer is preferably 1 μm or more and 1000 μm or less, especially 100 μm or more and 800 μm or less. When the average width of the sealing material layer is narrowed, it becomes easier to reduce the stress remaining in the sealing portion after laser sealing. On the other hand, if the maximum width of the sealing material layer is too narrow, bulk fracture of the sealing material layer is likely to occur when a large shear stress is applied to the sealing material layer. Furthermore, the accuracy of laser sealing tends to be lowered.

In the surface of the glass substrate on which the sealing material layer is formed, the ratio of the area where the sealing material layer is formed is preferably 1 to 50%, 10 to 48%, 20 to 45%, 23 to 43%. , in particular 25-40%. If the area ratio of the surface on which the sealing material layer is formed is large, residual stress is generated in or near the joint after sealing, and the glass substrate tends to break (for example, breakage such as cracks). On the other hand, when the ratio of the area where the sealing material layer is formed is large, it becomes possible to form many sealing patterns, that is, to fabricate many hermetic packages from one substrate. In the glass substrate with a sealing material layer of the present invention, since the difference in thermal expansion coefficient between the sealing material layer and the glass substrate is strictly defined, even if the ratio of the area where the sealing material layer is formed is increased, , it is possible to reduce the residual stress generated in or near the joint after sealing.

In the glass substrate with a sealing material layer of the present invention, it is preferable that the sealing material layer has a plurality of sealing patterns, and the sealing patterns have a closed loop shape. As a result, an airtight package group can be obtained, and by dividing this airtight package group, airtight packages corresponding to the number of sealing patterns can be efficiently produced. The number of sealing patterns is preferably 50-5000, 80-3000, especially 200-2500.

The method for manufacturing an airtight package of the present invention includes steps of preparing a package base, steps of preparing a glass substrate with a sealing material layer having a plurality of sealing patterns, and sealing with the base through the sealing material layer. A step of stacking and arranging the glass substrate with the material layer, and applying a laser beam from the glass substrate side to soften and deform the sealing material layer, thereby hermetically bonding the glass substrate and the package substrate to form an airtight package group. and dividing the airtight package group to obtain a plurality of airtight packages, wherein the glass substrate with the sealing material layer is the glass substrate with the sealing material layer described above.

In the step of laminating and arranging the package substrate and the glass substrate, the glass substrate may be arranged below the package substrate, but from the viewpoint of the efficiency of laser sealing, the glass substrate should be arranged above the package substrate. is preferred.

Various lasers can be used as the laser irradiated from the glass substrate side. In particular, semiconductor lasers, YAG lasers, _CO2 lasers, excimer lasers, and infrared lasers are preferred because they are easy to handle.

The beam shape of the laser light at the time of laser sealing is not particularly limited. The beam shape is generally circular, elliptical, or rectangular, but other shapes may be used. Moreover, the beam diameter of the laser light at the time of laser sealing is preferably 100 to 1000 mm.

The atmosphere for laser sealing is not particularly limited, and may be an air atmosphere or an inert atmosphere such as a nitrogen atmosphere.

Before laser sealing, it is preferable to preheat the package substrate at a temperature of 100° C. or higher and not higher than the heat-resistant temperature of the electric element. As a result, heat conduction to the package base can be inhibited during laser sealing, so that laser sealing can be performed efficiently.

It is preferable to perform the laser sealing while pressing the glass substrate. This can promote softening deformation of the sealing material layer during laser sealing.

It is preferable to further include a step of accommodating the electric element in the concave portion of the package base before stacking the package base and the glass substrate.

The airtight package of the present invention is an airtight package in which a glass substrate and a package base are airtightly integrated by a sealing material layer, and the glass substrate has a thickness of 0.2 mm and an average transmittance of 85% or more at 250 nm or more and less than 300 nm. The difference in thermal expansion coefficient between the sealing material layer and the glass substrate in a temperature range of 30 to 300° C. is 5 ppm/° C. or less. The technical features of the hermetic package of the present invention have already been described above, so a detailed description is omitted here.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the airtight package of the present invention. The airtight package 1 includes a glass substrate 10 and a package base 11. As shown in FIG. The package substrate 11 has a base portion 12, and further has a frame portion on the outer peripheral edge portion of the base portion 12, and a concave portion 13 is formed by these. An electric element 14 is accommodated in the recess 13 of the package base 11 . Electrical wiring (not shown) for electrically connecting the electrical element 14 and the outside is formed in the package base 11 .

A frame-shaped sealing material layer 15 is formed on the surface of the glass substrate 10 . The width of the sealing material layer 15 is smaller than the width of the top portion 16 of the frame portion of the package base 11 .

The glass substrate 10 and the package base 11 are laminated so that the sealing material layer 15 of the glass substrate 10 and the center line of the top portion 16 of the frame portion of the package base 11 in the width direction are aligned. After that, the laser light L emitted from the laser irradiation device 17 is irradiated along the sealing material layer 15 from the glass substrate 10 side. As a result, after the sealing material layer 15 softens and flows, the glass substrate 10 and the package base 11 are hermetically sealed to form the hermetic structure of the hermetic package 1 .

The present invention will be described in detail below based on examples. It should be noted that the following examples are merely illustrative. The present invention is by no means limited to the following examples.

(Sample No. 1)
First, a silicon substrate (thermal expansion coefficient at 30 to 300° C. 3.8 ppm/° C., square 4 mm) was prepared.

Next, a glass substrate made of alkali borosilicate glass (thermal expansion coefficient at 30 to 300° C.: 4.2 ppm/° C., square: 4 mm, thickness: 0.2 mm) was prepared. This glass substrate has a glass composition of 70% by mass _{SiO2 ,} 5.9% _{Al2O3 ,} 18% B2O3, ₁ % Li2O, ₂ % _Na2O , and _K2O3 . %, Cl 0.1%, TiO ₂ 0.0001%, Fe ₂ O ₃ 0.0001%, thickness 0.2 mm, average transmittance at 250 nm or more and less than 300 nm is 91%, thickness 0.2 mm , the average transmittance at 300 nm or more and less than 1000 nm is 92%.

A sealing material was prepared by mixing 73% by volume of bismuth-based glass powder and 27% by volume of ceramic powder. Here, the average particle diameter _D50 of the bismuth-based glass powder is 1.0 μm, the ₉₉ % particle diameter D99 is 2.8 μm, the average particle diameter _D50 of the ceramic powder is 1.0 μm, and the ₉₉ % particle diameter D99 is 2.8 μm. The bismuth-based glass has a glass composition of 36.5% Bi ₂ O ₃ , 28.5% B ₂ O ₃ , 9.5% ZnO, 1.5% Al ₂ O ₃ , and MnO ₂ in terms of mol %. 9.5% CuO 13.6% Fe ₂ O ₃ 0.9%. Also, the ceramic powder is β-eucryptite.

When the thermal expansion coefficient of the obtained sealing material was measured, the thermal expansion coefficient was 7.1 ppm/°C. The coefficient of thermal expansion was measured with a push rod type TMA apparatus, and the measurement temperature range was 30 to 300°C.

Next, the sealing material was coated on the glass substrate, dried, debindered, and sintered to form a closed loop-shaped sealing material layer. Specifically, first, the sealing material, vehicle and solvent are kneaded so that the viscosity is within the range of 90±20 Pa·s (25° C., Shear rate: 4), and then the powder is further milled with a three-roll mill. The mixture was kneaded until it was uniformly dispersed and made into a paste to obtain a sealing material paste. The vehicle was prepared by dissolving an ethyl cellulose organic resin in a glycol ether solvent. Next, a sealing material paste was printed in a frame shape on the outer peripheral edge of the glass substrate by a screen printer. Furthermore, after drying at 110 ° C. for 10 minutes in an air atmosphere to obtain a dry film, heat treatment is performed in an electric furnace at 350 ° C. for 15 minutes → 500 ° C. for 10 minutes to remove the binder and bake the dry film. It was bonded to form a sealing material layer having an average width of about 400 μm and an average thickness of about 5 μm.

Finally, the glass substrate with the sintered sealing material layer and the silicon substrate are laminated, and a laser beam is irradiated from the glass substrate side to soften and flow the sealing material layer, thereby hermetically integrating the glass substrate and the silicon substrate. An airtight package was obtained by The laser output is 10 W, the scanning speed is 15 mm/sec, and the beam diameter is φ500 μm.

(Sample No. 2)
Sample no. Sample No. 1 except that a glass substrate made of alkali borosilicate glass (thermal expansion coefficient at 30 to 300° C. 9.9 ppm/° C., square 4 mm, thickness 0.2 mm) was used instead of the glass substrate of Sample No. 1. An airtight package was obtained in the same manner as in 1. This glass substrate has a glass composition of SiO ₂ 70.2%, Al ₂ O ₃ 1.6%, B ₂ O ₃ 2.3%, Na ₂ O 9.6%, and K ₂ O 9 in mass %. .1%, BaO 7.0%, Cl 0.4%, SrO 0.1%, TiO ₂ 0.0001%, Fe ₂ O ₃ 0.0001%, thickness 0.2 mm, 250 nm or more and less than 300 nm The average transmittance is 89% at the thickness of 0.2 mm, and the average transmittance at the thickness of 300 nm or more and less than 1000 nm is 92%.

(Sample No. 3)
Sample no. 1 except that a quartz substrate (thermal expansion coefficient 0.6 ppm/° C. at 30 to 300° C., square 4 mm, thickness 0.5 mm) was used instead of the glass substrate of sample No. 1. An airtight package was obtained in the same manner as in 1.

(evaluation)
Sample no. The hermetic packages obtained in 1 to 3 were observed for cracks, and subjected to a temperature cycle test and a high-temperature, high-humidity, and high-pressure test. Table 1 shows the results.

The presence or absence of cracks was evaluated by observing the vicinity of the sealing material layer of the resulting hermetic package with an optical microscope.

In the temperature cycle test, the obtained airtight package was subjected to repeated temperature cycles under the conditions of 125 ° C. ⇔ -55 ° C., 1000 cycles, and then the vicinity of the sealing material layer was observed and evaluated. A sample in which no cracks, peeling, etc. were observed was evaluated as "◯", and a sample in which it was observed was evaluated as "X".

High-temperature, high-humidity, high-pressure test: PCT (Pressure Cooker Test) is performed by holding the obtained airtight package under the conditions of 121 ° C., 100% humidity, 2 atm, and 24 hours in a high-temperature, high-humidity, high-pressure environment, and then using a sealing material. The evaluation was made by observing the vicinity of the layer, and evaluation was given as "Good" when deterioration, cracks, peeling, etc. were not observed, and as "Poor" when observed.

As can be seen from Table 1, sample no. 1 and sample no. The airtight package obtained in 2 was evaluated favorably in the presence or absence of cracks, the temperature cycle test, and the high-temperature, high-humidity, and high-pressure test. On the other hand, sample no. The airtight package obtained in 3 was unsatisfactory in the presence or absence of cracks, temperature cycle test, and high-temperature, high-humidity, and high-pressure test.

A glass substrate made of alkali borosilicate glass (thermal expansion coefficient 4.2 ppm/° C. at 30 to 300° C., thickness 0.2 mm, square 44 mm) was prepared. This glass substrate has a glass composition of 70% by mass _{SiO2 ,} 5.9% _{Al2O3 ,} 18% B2O3, ₁ % Li2O, ₂ % _Na2O , and _K2O3 . %, Cl 0.1%, TiO ₂ 0.0001%, Fe ₂ O ₃ 0.0001%, thickness 0.2 mm, average transmittance at 250 nm or more and less than 300 nm is 91%, thickness 0.2 mm , the average transmittance at 300 nm or more and less than 1000 nm is 92%. On one surface of this glass substrate, 100 square 3.3 mm closed-loop sealing patterns (average thickness of sealing material layer: 5 μm, average width of sealing material layer: 400 μm) were formed in the same manner as in Example 1. Individually formed, a glass substrate with a sealing material layer was obtained. FIG. 2 is a photograph showing this glass substrate with a sealing material layer.

Also, a silicon substrate (thermal expansion coefficient at 30 to 300° C.: 3.8 ppm/° C.) was prepared. Here, the ratio of the area on which the sealing material layer was formed was 27% on the surface of the glass substrate on which the sealing material layer was formed.

Next, the silicon substrate and the glass substrate with the sealing material layer were laminated with the sealing material layer interposed therebetween. Then, in the same manner as in Example 1, a laser beam is irradiated from the glass substrate side to soften and deform the sealing material layer, thereby hermetically sealing the glass substrate and the silicon substrate to obtain an airtight package group. rice field. Finally, the airtight package group was divided by dicing so as not to divide the sealing pattern, and 100 airtight packages were obtained.

Instead of the glass substrate according to Example 2, a glass substrate made of alkali borosilicate glass (thermal expansion coefficient at 30 to 300 ° C. 9.9 ppm / ° C., 4 mm square, 0.2 mm thickness) was used. A glass substrate with a sealing material layer and an airtight package were obtained in the same manner as in 2. This glass substrate has a glass composition of SiO ₂ 70.2%, Al ₂ O ₃ 1.6%, B ₂ O ₃ 2.3%, Na ₂ O 9.6%, and K ₂ O 9 in mass %. .1%, BaO 7.0%, Cl 0.4%, SrO 0.1%, TiO ₂ 0.0001%, Fe ₂ O ₃ 0.0001%, thickness 0.2 mm, 250 nm or more and less than 300 nm The average transmittance is 89% at the thickness of 0.2 mm, and the average transmittance at the thickness of 300 nm or more and less than 1000 nm is 92%.

The airtight package of the present invention is suitable for airtight packages in which electric elements such as sensor chips and ultraviolet LEDs are mounted. It can also be suitably applied to an airtight package or the like that accommodates the .

1 Airtight Package 10 Glass Substrate 11 Package Substrate 12 Base 13 Recess 14 Electric Element

15 Sealing material layer 16 Top of recess 17 Laser irradiation device L Laser light

Claims (12)

A glass substrate with a sealing material layer in which a sealing material layer is formed on a glass substrate,
The glass substrate has a thickness of 0.2 mm and an average transmittance of 85% or more at 250 nm or more and less than 300 nm,
A glass substrate with a sealing material layer, wherein the difference in thermal expansion coefficient between the sealing material layer and the glass substrate is 5 ppm/°C or less in a temperature range of 30 to 300°C. 2. The glass substrate with a sealing material layer according to claim 1, wherein the ratio of the area where the sealing material layer is formed on the surface of the glass substrate on which the sealing material layer is formed is 1 to 50%. The glass substrate with a sealing material layer according to claim 1 or 2, wherein the sealing material layer has a plurality of sealing patterns, and the sealing pattern has a closed loop shape. The sealing material layer is a sintered body of composite powder containing at least bismuth-based glass powder and refractory filler powder,
With a sealing material layer according to any one of claims 1 to 3, wherein the content of the bismuth-based glass in the sealing material layer is 65 to 95% by volume, and the content of the refractory filler is 5 to 35% by volume. glass substrate. 5. The glass substrate with a sealing material layer according to claim 1, wherein the sealing material layer does not substantially contain a laser absorber. 6. The method according to claim 1, wherein the average thickness of the sealing material layer is 15 μm or less, and the value obtained by dividing the average thickness of the sealing material layer by the thickness of the glass substrate is 0.005 to 0.5. glass substrate with a layer of sealing material. The average width of the sealing material layer is 1000 μm or less, and the value obtained by dividing the average thickness of the sealing material layer by the average width of the sealing material layer is 0.005 to 0.1. A glass substrate with a sealing material layer according to 1. The glass substrate with a sealing material layer according to any one of claims 1 to 7, wherein the glass substrate is rectangular, circular, or circular with an orientation flat. 9. The glass substrate with a sealing material layer according to claim 1, wherein an antireflection film is formed on either surface of the glass substrate. 10. The glass substrate with a sealing material layer according to claim 1, which is used for sealing with a laser beam. providing a package substrate;
preparing a glass substrate with a sealing material layer having a plurality of sealing patterns;
a step of laminating and arranging the package base and the glass substrate with the sealing material layer through the sealing material layer;
a step of irradiating a laser beam from the glass substrate side to soften and deform the sealing material layer to hermetically seal the glass substrate and the package substrate to obtain an airtight package group;
dividing the hermetic package group to obtain a plurality of hermetic packages;
A method for manufacturing an airtight package, wherein the glass substrate with a sealing material layer is the glass substrate with a sealing material layer according to any one of claims 1 to 11. In an airtight package in which a glass substrate and a package base are hermetically integrated by a sealing material layer,
The glass substrate has a thickness of 0.2 mm and an average transmittance of 85% or more at 250 nm or more and less than 300 nm,
A hermetic package, wherein the difference in thermal expansion coefficient between the sealing material layer and the glass substrate is 5 ppm/°C or less in a temperature range of 30 to 300°C.

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