WO2018216587A1

WO2018216587A1 - Method for producing hermetic package, and hermetic package

Info

Publication number: WO2018216587A1
Application number: PCT/JP2018/019032
Authority: WO
Inventors: 徹白神
Original assignee: 日本電気硝子株式会社
Priority date: 2017-05-23
Filing date: 2018-05-17
Publication date: 2018-11-29
Also published as: JPWO2018216587A1; TW201901866A

Abstract

This method for producing a hermetic package is characterized by comprising: a step for preparing a ceramic substrate and forming a first sealing material layer on the ceramic substrate; a step for preparing a glass cover and forming a second sealing material layer on the glass cover; a step for laminating the ceramic substrate and the glass cover upon each other so that the first sealing material layer and the second sealing material layer are in contact with each other; and a step for obtaining a hermetic package by hermetically sealing the first sealing material layer and the second sealing material layer against each other by irradiating the first sealing material layer and the second sealing material layer with laser light from the glass cover side, thereby softening and deforming the first sealing material layer and the second sealing material layer.

Description

Airtight package manufacturing method and airtight package

The present invention relates to a method for manufacturing a hermetic package and a hermetic package, and more specifically, manufacturing a hermetic package in which a ceramic substrate and a glass lid are hermetically sealed by a sealing process using laser light (hereinafter referred to as laser sealing). The present invention relates to a method and an airtight package manufactured by the method.

The airtight package generally includes a ceramic base, a light-transmitting glass lid, and internal elements housed therein.

内部 Internal elements such as sensor chips mounted inside the airtight package may deteriorate due to moisture entering from the surrounding environment. Conventionally, an organic resin adhesive having low-temperature curability has been used to integrate the ceramic substrate and the glass lid. However, since the organic resin adhesive cannot completely shield moisture and gas, there is a possibility that the internal element deteriorates with time.

On the other hand, when a sealing material containing glass powder and refractory filler powder is used, the sealed portion is hardly deteriorated by moisture in the surrounding environment, and it becomes easy to ensure the airtight reliability of the airtight package.

However, since the glass powder has a higher softening temperature than the organic resin adhesive, there is a risk that the internal element is thermally deteriorated during sealing. In recent years, laser sealing has attracted attention in recent years. According to laser sealing, only the portion to be sealed can be locally heated, and the ceramic base and the glass lid can be hermetically integrated without thermally deteriorating the internal elements.

JP 2013-239609 A JP 2014-236202 A

By the way, when laser sealing the ceramic substrate and the glass lid, the thermal conductivity of the ceramic substrate is higher than when laser sealing the glass substrate and the glass lid, and the temperature of the ceramic substrate rises during laser sealing. Therefore, there is a problem that the sealing material layer and the ceramic substrate are difficult to react and it is difficult to ensure the laser sealing strength.

On the other hand, when the output of the laser beam is increased, the reactivity between the sealing material layer and the ceramic substrate can be increased. In this case, the portion in contact with the locally heated sealing material layer in the glass lid is locally increased. Since a large temperature difference occurs in the unheated part, the glass lid is easily damaged by the thermal shock, and there arises a problem that the airtight reliability in the airtight package cannot be secured.

Therefore, the present invention has been made in view of the above circumstances, and its technical problem is that when laser sealing a ceramic substrate and a glass lid, both laser sealing strength and airtight reliability can be achieved at a high level. The idea is to create an airtight package manufacturing method.

As a result of intensive studies, the inventor formed the first sealing material layer on the ceramic substrate and the second sealing material layer on the glass lid, and then the first sealing material layer and the second sealing material layer. The present inventors have found that the above technical problem can be solved when laser sealing is performed in a state in which the adhesive material layer is in contact, and the present invention proposes. That is, in the method for manufacturing an airtight package of the present invention, a ceramic substrate is prepared, a step of forming a first sealing material layer on the ceramic substrate, a glass lid is prepared, and a second is formed on the glass lid. A step of forming a sealing material layer, a step of laminating and arranging the ceramic base and the glass lid so that the first sealing material layer and the second sealing material layer are in contact, and laser light from the glass lid side. By irradiating and softening and deforming the first sealing material layer and the second sealing material layer, the first sealing material layer and the second sealing material layer are hermetically sealed to form an airtight package. And a step of obtaining.

In the method for manufacturing an airtight package of the present invention, a first sealing material layer is formed on a ceramic substrate and a second sealing material layer is formed on a glass lid, and then the first sealing material layer and the second sealing material layer are formed. It is characterized in that laser sealing is performed in a state where the adhesive material layer is in contact. In this way, since the sealing material layer is formed on the ceramic substrate and the glass lid by firing in an electric furnace or the like before laser sealing, a strong reaction layer can be formed on the surface layer of the ceramic substrate, and glass A strong reaction layer can also be formed on the surface of the lid. Further, since both the first sealing material layer and the second sealing material layer are softened and flowed and melted at the time of laser sealing, the ceramic base and the glass lid can be easily hermetically integrated. Furthermore, since the local heating temperature at the time of laser sealing can be lowered, not only is the glass lid difficult to break due to thermal shock, but also heat transmitted to the internal elements due to heat conduction can be reduced. As a result, the laser sealing strength and the hermetic reliability of the hermetic package can be enhanced at the same time, and thermal deterioration of the internal elements can be prevented.

Further, in the method for producing an airtight package of the present invention, the first sealing material layer contains at least one of bismuth glass, silver phosphate glass, and tellurium glass, and the second sealing material. It is preferable that the layer contains one or more of bismuth glass, silver phosphate glass, and tellurium glass. Bismuth glass, especially bismuth glass containing a transition metal oxide in the glass composition, has a feature that it is easy to form a reaction layer on the surface of the ceramic substrate during laser sealing compared to other glass systems. Have. Moreover, when a refractory filler powder is introduced, the mechanical strength of the sealing material layer can be increased, and the thermal expansion coefficient of the sealing material layer can be reduced. Silver phosphate glass and tellurium glass are easier to soften and flow at a lower temperature than bismuth glass, and can reduce thermal distortion that occurs after laser sealing, thus improving thermal and mechanical reliability. It has the feature that it can be. Furthermore, silver phosphate glass and tellurium glass, like bismuth glass, can increase the mechanical strength of the sealing material layer when mixed with refractory filler powder, and the thermal expansion of the sealing material layer. The coefficient can be reduced. Here, “bismuth-based glass” refers to glass mainly composed of Bi ₂ O ₃ , and specifically refers to glass containing 25 mol% or more of Bi ₂ O ₃ in the glass composition. “Silver phosphate glass” refers to a glass mainly composed of Ag ₂ O and P ₂ O ₅ , specifically, 20 mol% of Ag ₂ O and P ₂ O ₅ in the total amount in the glass composition. It refers to the glass containing above. “Tellurium-based glass” refers to glass containing TeO ₂ as a main component, and specifically refers to glass containing 20 mol% or more of TeO _{2 in the} glass composition.

In addition, the method for manufacturing an airtight package of the present invention has an average thickness of the first sealing material layer of less than 8.0 μm, an average thickness of the second sealing material layer of less than 8.0 μm, and the first sealing material layer. It is preferable to regulate the sum of the average thickness of the material layer and the average thickness of the second sealing material layer to less than 15.0 μm. In this way, since the residual stress in the hermetic package after laser sealing is reduced, the hermetic reliability of the hermetic package can be improved.

In the method for manufacturing an airtight package of the present invention, it is preferable that the average width of the first sealing material layer is restricted to less than 2000 μm and the average width of the second sealing material layer is restricted to less than 2000 μm. In this way, since the residual stress in the hermetic package after laser sealing is reduced, the hermetic reliability of the hermetic package can be improved.

In addition, in the method for manufacturing an airtight package of the present invention, it is preferable to use a ceramic base having a base and a frame provided on the base, and to form a first sealing material layer on the top of the frame.

Moreover, it is preferable that the manufacturing method of the hermetic package of the present invention further includes a step of polishing the surface of the first sealing material layer.

In the method for manufacturing an airtight package of the present invention, it is preferable that the ceramic substrate is glass ceramic, aluminum nitride, aluminum oxide, or a composite material thereof.

Further, in the method for manufacturing an airtight package of the present invention, it is preferable that the sensor element or the LED element is accommodated in the frame portion of the ceramic substrate.

The hermetic package of the present invention is a hermetic package having a ceramic base and a glass lid, wherein the ceramic base has a base and a frame provided on the base, and a bismuth-based material is formed on the top of the frame of the ceramic base. A first sealing material layer containing at least one of glass, silver phosphate glass, and tellurium glass is formed, and bismuth glass, silver phosphate glass, and tellurium glass are formed on the glass lid. A second sealing material layer containing any one or more of the above is formed, and the first sealing material layer and the second sealing material layer are hermetically integrated in a state of contact arrangement It is characterized by that.

In the hermetic package of the present invention, the first sealing material layer contains bismuth-based glass containing a transition metal oxide in the glass composition, and the second sealing material layer transitions in the glass composition. It is preferable to contain a bismuth glass containing a metal oxide.

The hermetic package of the present invention has an average thickness of the first sealing material layer of less than 8.0 μm, an average thickness of the second sealing material layer of less than 8.0 μm, and the first sealing material layer. The total of the average thickness of the adhesive material layer and the average thickness of the second sealing material layer is preferably less than 15.0 μm.

In the hermetic package of the present invention, it is preferable that the average width of the first sealing material layer is less than 2000 μm and the average width of the second sealing material layer is less than 2000 μm.

In the hermetic package of the present invention, it is preferable that the ceramic substrate is glass ceramic, aluminum nitride, aluminum oxide, or a composite material thereof.

In the hermetic package of the present invention, it is preferable that the sensor element or the LED element is accommodated in the frame portion of the ceramic substrate.

It is a section conceptual diagram for explaining one embodiment of the present invention.

The method for manufacturing an airtight package according to the present invention comprises preparing a ceramic substrate, forming a first sealing material layer on the ceramic substrate, preparing a glass lid, and second sealing on the glass lid. Forming a material layer.

The ceramic substrate preferably has a base and a frame provided on the base. In this way, it becomes easy to accommodate an internal element such as a sensor chip in the space in the ceramic substrate. The frame portion of the ceramic base is preferably formed in a frame shape along the outer peripheral edge region of the ceramic base. In this way, the effective area that functions as a device can be expanded. Furthermore, internal elements such as sensor chips can be easily accommodated in the frame portion of the ceramic substrate, and wiring bonding and the like can be easily performed.

The surface roughness Ra of the surface of the region where the sealing material layer is disposed at the top of the frame is preferably less than 1.0 μm. If the surface roughness Ra of the surface increases, the accuracy of laser sealing tends to decrease. Here, the “surface roughness Ra” can be measured by, for example, a stylus type or non-contact type laser film thickness meter or surface roughness meter.

The ceramic substrate is preferably one of glass ceramic, aluminum nitride, aluminum oxide, or a composite material thereof (for example, aluminum nitride and glass ceramic integrated). Since the glass ceramic can easily form the thermal via, it is possible to appropriately prevent the airtight package from excessively generating heat during the operation of the internal element. Since aluminum nitride and aluminum oxide have good heat dissipation, it is possible to appropriately prevent the airtight package from excessively generating heat during the operation of the internal element.

Glass pigment, aluminum nitride, and aluminum oxide may have a black pigment dispersed therein. In this way, the ceramic substrate can absorb the laser light transmitted through the sealing material layer. As a result, since the heat flow toward the ceramic base having high thermal conductivity can be reduced during laser sealing, laser sealing can be performed efficiently.

In the case of a ceramic substrate in which a black pigment is dispersed, it has a property of absorbing laser light to be irradiated, that is, a thickness of 0.5 mm and a total light transmittance of 10 at the wavelength of the laser light to be irradiated (for example, 808 nm). % Or less (preferably 5% or less). In this way, the ceramic substrate can be efficiently heated.

The thickness of the base of the ceramic substrate is preferably 0.1 to 2.5 mm, particularly preferably 0.2 to 1.5 mm. Thereby, thickness reduction of an airtight package can be achieved.

The average thickness of the sealing material layer (the first sealing material layer and / or the second sealing material layer) is preferably less than 8.0 μm, particularly 1.0 μm or more and less than 6.0 μm. Furthermore, the sum of the average thickness of the first sealing material layer and the average thickness of the second sealing material layer is preferably less than 15.0 μm, in particular less than 12.0 μm. The smaller the average thickness of the sealing material layer, the more the stress remaining in the sealing portion after laser sealing can be reduced even if the thermal expansion coefficients of the sealing material layer, the ceramic substrate and the glass lid are mismatched. . In addition, the accuracy of laser sealing can be increased. Examples of the method for regulating the average thickness of the sealing material layer as described above include a method of thinly applying a sealing material paste and a method of polishing the surface of the sealing material layer.

The average width of the sealing material layer (the first sealing material layer and / or the second sealing material layer) is preferably less than 2000 μm, less than 1200 μm, particularly 200 μm or more and less than 800 μm. When the average width of the sealing material layer is narrowed, the stress remaining in the sealing portion after laser sealing can be reduced. Furthermore, the width of the frame portion of the ceramic substrate can be reduced, and the effective area that functions as a device of an airtight package can be expanded.

The surface roughness Ra of the sealing material layer (the first sealing material layer and / or the second sealing material layer) is preferably less than 0.5 μm and not more than 0.2 μm, particularly 0.01 to 0.15 μm. It is. If it does in this way, the adhesiveness of a 1st sealing material layer and a 2nd sealing material layer will improve, and the precision of laser sealing will improve. Here, the “surface roughness Ra” can be measured by, for example, a stylus type or non-contact type laser film thickness meter or surface roughness meter. In addition, as a method of regulating the surface roughness Ra of the sealing material layer as described above, the method of polishing the surface of the sealing material layer, the particle size of the refractory filler powder contained in the sealing material layer is reduced. A method is mentioned.

The first sealing material layer and the second sealing material layer may have the same material configuration, and may contain glass powder having the same glass composition. In this way, the first sealing material layer and the second sealing material layer have the same behavior with respect to heat such as fluidity and thermal expansion coefficient, so that the laser sealing process can be easily controlled.

The first sealing material layer and the second sealing material layer may have different material configurations, and may contain glass powders having different glass compositions. In this way, since the thermal expansion coefficients of the first sealing material layer and the second sealing material layer can be individually adjusted, the first sealing material layer, the second sealing material layer, the ceramic It becomes easy to optimize the thermal expansion coefficient between the base and the glass lid. As a result, it becomes easy to prevent breakage of the glass lid or the like after laser sealing.

The sealing material layer is a sintered body of a sealing material and is softened and deformed during laser sealing. Various glass (for example, bismuth glass, silver phosphate glass, tellurium glass, tin phosphate glass, vanadium glass, etc.) can be used as the sealing material, and in particular, the laser sealing strength is ensured. From the viewpoint, it is preferable to use a glass containing a transition metal oxide in the glass composition. The content of the transition metal oxide in the glass is preferably 1 mol% or more, 3 mol% or more, 5 mol% or more, 10 mol% or more, particularly 15 to 30 mol%, in order to improve the laser absorption characteristics.

The bismuth-based glass may contain, as a glass composition, mol% of Bi ₂ O ₃ 28 to 60%, B ₂ O ₃ 15 to 37%, ZnO 1 to 30%, and transition metal oxide 0 to 40%. preferable. In addition, in description of the glass composition range of bismuth-type glass,% display points out mol%.

The reason for limiting the content range of each component as described above will be described below.

Bi ₂ O ₃ is a main component for lowering the softening point, and its content is preferably 28 to 60%, 33 to 55%, particularly preferably 35 to 45%. When Bi ₂ content of O ₃ is too small, too high softening point, the fluidity tends to decrease. On the other hand, when the content of Bi ₂ O ₃ is too large, the glass is liable to be devitrified at the time of laser sealing, and fluidity is liable to decrease due to the devitrification.

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 preferably 25 to 30%. If the content of B ₂ O ₃ is too small, it becomes difficult to form a glass network, so that the glass is easily devitrified at the time of laser sealing. On the other hand, when the content of B ₂ O ₃ is too large, the viscosity of the glass becomes high, the fluidity tends to decrease.

ZnO is a component that enhances devitrification resistance, and its content is preferably 1 to 30%, 3 to 25%, 5 to 22%, particularly preferably 9 to 20%. When the content of ZnO is out of the above range, the component balance of the glass composition is impaired, and the devitrification resistance tends to decrease.

The transition metal oxide is a component having laser absorption characteristics, and its content is 0 to 40%, 1 to 40%, 3 to 40%, 5 to 40%, 12 to 40%, particularly 15 to 30 mol%. Is preferred. When there is too much content of a transition metal oxide, devitrification resistance will fall easily.

If CuO is added, the laser absorption characteristics can be enhanced. The CuO content is preferably 0 to 40%, 5 to 35%, 10 to 30%, particularly preferably 15 to 25%. When there is too much content of CuO, the component balance of a glass composition will be impaired and devitrification resistance will fall easily conversely. In order to lower the softening point of bismuth-based glass, it is necessary to introduce a large amount of Bi ₂ O ₃ into the glass composition. However, if the content of Bi ₂ O ₃ is increased, the glass is not sealed during laser sealing. It becomes easy to devitrify, and fluidity tends to decrease due to this devitrification. In particular, when the Bi ₂ O ₃ content is 30% or more, the tendency becomes remarkable. As a countermeasure, if CuO is added, devitrification of the glass can be effectively suppressed even if the content of Bi ₂ O ₃ is 30% or more.

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 preferably 0.5 to 3%. When the content of Fe ₂ O ₃ is too large, balance of components the glass composition is impaired, the devitrification resistance is liable to decrease conversely.

MnO is a component that enhances laser absorption characteristics. The content of MnO is preferably 0 to 25%, in particular 5 to 15%. When there is too much content of MnO, devitrification resistance will fall easily.

MoO ₃ is a component that enhances laser absorption characteristics. The content of MoO ₃ is preferably 0 to 25%, in particular 5 to 15%. When the content of MoO ₃ is too large, the devitrification resistance is liable 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 has an action of increasing the softening point. For this reason, the content of SiO ₂ is preferably 0 to 5%, 0 to 3%, 0 to 2%, particularly preferably 0 to 1%. If the content of SiO ₂ is too large, the glass tends to be devitrified during laser sealing.

Al ₂ O ₃ is a component that enhances water resistance, and its content is preferably 0 to 10%, 0 to 5%, particularly preferably 0.1 to 2%. When the content of Al ₂ O ₃ is too large, there is a possibility that the softening point is unduly increased.

Li ₂ O, Na ₂ O and K ₂ O are components that reduce devitrification resistance. Therefore, the contents of Li ₂ O, Na ₂ O and K ₂ O are 0 to 5%, 0 to 3%, particularly 0 to less than 1%, respectively.

MgO, CaO, SrO, and BaO are components that increase devitrification resistance, but are components that increase the softening point. Therefore, the contents of MgO, CaO, SrO and BaO are 0 to 20%, 0 to 10%, particularly 0 to 5%, respectively.

Sb ₂ O ₃ is a component that enhances devitrification resistance, and its content is preferably 0 to 5%, particularly preferably 0 to 2%. When the content of Sb ₂ O ₃ is too large, balance of components the glass composition is impaired, the devitrification resistance is liable to decrease conversely.

The silver phosphate glass contains, as a glass composition, mol%, Ag ₂ O 10 to 50%, P ₂ O ₅ 10 to 35%, ZnO 3 to 25%, transition metal oxide 0 to 30%. Is preferred. In addition, in description of the glass composition range of silver phosphate glass,% display points out mol%.

Ag ₂ O is a component that increases the water resistance because it lowers the melting point of the glass and hardly dissolves in water. The content of Ag ₂ O is preferably 10 to 50%, particularly preferably 20 to 40%. If Ag 2 _O content is too small, the viscosity of the glass becomes high, the flowability tends to decline, water resistance tends to decrease. On the other hand, when the content of Ag 2 _O is too large, vitrification tends to be difficult.

P ₂ O ₅ is a component that lowers the melting point of glass. Its content is preferably 10 to 35%, particularly preferably 15 to 25%. When the content of P ₂ O ₅ is too small, vitrification tends to be difficult. On the other hand, when the content of P ₂ O ₅ is too large, weather resistance, water resistance tends to decrease.

ZnO is a component that enhances devitrification resistance, and its content is preferably 3 to 25%, 5 to 22%, particularly preferably 9 to 20%. When the content of ZnO is out of the above range, the component balance of the glass composition is impaired, and the devitrification resistance tends to decrease.

The transition metal oxide is a component having laser absorption characteristics, and its content is preferably 0 to 30%, 1 to 30%, particularly preferably 3 to 15%. When there is too much content of a transition metal oxide, devitrification resistance will fall easily.

If CuO is added, the laser absorption characteristics can be improved. The content of CuO is preferably 0 to 30%, 1 to 30%, particularly 3 to 15%. When there is too much content of CuO, the component balance of a glass composition will be impaired and devitrification resistance will fall easily conversely.

TeO ₂ is a glass forming component and a component that lowers the melting point of glass. The content of TeO ₂ is preferably 0 to 40%, particularly 10 to 30%.

Nb ₂ O ₅ is a component that improves water resistance. The content of Nb ₂ O ₅ is preferably 0 to 25%, particularly 1 to 12%. When the content of Nb ₂ O ₅ is too large, the viscosity of the glass becomes high, the fluidity tends to decrease.

The tellurium-based glass preferably contains TeO ₂ 20 to 80%, Nb ₂ O ₅ 0 to 25%, and transition metal oxide 0 to 40% in terms of glass composition. In the description of the glass composition range of tellurium-based glass,% display indicates mol%.

TeO ₂ is a glass forming component and a component that lowers the melting point of glass. The content of TeO ₂ is preferably 20 to 80%, particularly preferably 40 to 75%.

Nb ₂ O ₅ is a component that improves water resistance. The content of Nb ₂ O ₅ is preferably 0 to 25%, 1 to 20%, particularly preferably 5 to 15%. When the content of Nb ₂ O ₅ is too large, the viscosity of the glass becomes high, the fluidity tends to decrease.

The transition metal oxide is a component having laser absorption characteristics, and its content is preferably 0 to 40%, 5 to 30%, particularly preferably 15 to 25%. When there is too much content of a transition metal oxide, devitrification resistance will fall easily.

If CuO is added, the laser absorption characteristics can be improved. The CuO content is preferably 0 to 40%, 5 to 30%, particularly preferably 15 to 25%. When there is too much content of CuO, the component balance of a glass composition will be impaired and devitrification resistance will fall easily conversely.

The average particle diameter _{D 50} of the glass powder less than 15μm, 0.5 ~ 10μm, particularly 0.8 ~ 5 [mu] m is preferred. As the average particle diameter D ₅₀ of the glass powder is small, the softening point of the glass powder is lowered.

The sealing material layer (the first sealing material layer and / or the second sealing material layer) may contain a refractory filler powder. The sealing material layer preferably contains 50 to 100% by volume of glass and 0 to 50% by volume of refractory filler powder, and contains 55 to 85% by volume of glass and 15 to 45% by volume of refractory filler powder. More preferably, it contains 60 to 80% by volume of glass and 20 to 40% by volume of refractory filler powder. If the refractory filler powder is added, the thermal expansion coefficient of the sealing material is easily matched with the thermal expansion coefficient of the ceramic substrate and the glass lid. As a result, it becomes easy to prevent a situation in which undue stress remains in the sealed portion after laser sealing. On the other hand, when the content of the refractory filler powder is too large, the glass content is relatively decreased, so that the surface smoothness of the sealing material layer is lowered and the accuracy of laser sealing is likely to be lowered.

As the refractory filler powder, it is preferable to use one or more selected from cordierite, zircon, tin oxide, niobium oxide, zirconium phosphate ceramic, willemite, β-eucryptite, and β-quartz solid solution. These refractory filler powders have a low mechanical expansion coefficient, a high mechanical strength, and a good compatibility with bismuth glass, silver phosphate glass, tellurium glass, and the like.

The average particle diameter _{D 50} of the refractory filler powder is preferably less than 2 [mu] m, especially 0.1μm or more and less than 1.5 [mu] m. When the average particle diameter D ₅₀ of the refractory filler powder is too large, the surface smoothness of the sealing material layer is liable to lower, likely the average thickness of the sealing material layer is increased, as a result, the laser sealing precision Tends to decrease.

The 99% particle size D ₉₉ of the refractory filler powder is preferably less than 5 μm, 4 μm or less, particularly 0.3 μm or more and 3 μm or less. If the 99% particle size D ₉₉ of the refractory filler powder is too large, the surface smoothness of the sealing material layer tends to decrease, and the average thickness of the sealing material layer tends to increase, resulting in laser sealing. Accuracy is likely to decrease. Here, “99% particle diameter D ₉₉ ” refers to a value measured on a volume basis by a laser diffraction method. Here, “average particle diameter D ₅₀ ” and “99% particle diameter D ₉₉ ” indicate values measured on a volume basis by a laser diffraction method.

The sealing material layer (the first sealing material layer and / or the second sealing material layer) may further contain a laser absorbing material in order to enhance the laser absorption characteristics. Has the effect of promoting devitrification. Therefore, the content of the laser absorbing material in the sealing material is preferably 10% by volume or less, 5% by volume or less, 1% by volume or less, and 0.5% by volume or less, particularly preferably not substantially contained. When the devitrification resistance of the glass is good, a laser absorbing material may be introduced in an amount of 1% by volume or more, particularly 3% by volume or more in order to improve the laser absorption characteristics. As the laser absorber, Cu-based oxides, Fe-based oxides, Cr-based oxides, Mn-based oxides, spinel-type composite oxides, and the like can be used.

The thermal expansion coefficient of the sealing material layer (the first sealing material layer and / or the second sealing material layer) is preferably 55 × 10 ⁻⁷ to 105 × 10 ⁻⁷ / ° C., 60 × 10 ^−7. ˜82 × 10 ⁻⁷ / ° C., in particular 65 × 10 ⁻⁷ to 76 × 10 ⁻⁷ / ° C. In this way, the thermal expansion coefficient of the sealing material layer matches the thermal expansion coefficient of the ceramic base or the glass lid, and the stress remaining in the sealing portion is reduced.

The difference in thermal expansion coefficient between the sealing material layer and the ceramic substrate is preferably less than 65 × 10 ⁻⁷ / ° C., particularly 25 × 10 ⁻⁷ / ° C. or less, and the difference in thermal expansion coefficient between the sealing material layer and the glass lid is 75 × It is preferably less than 10 ⁻⁷ / ° C., particularly preferably 25 × 10 ⁻⁷ / ° C. or less, and the difference in thermal expansion coefficient between the first sealing material layer and the second sealing material layer is less than 30 × 10 ⁻⁷ / ° C. It is preferably less than 10 × 10 ⁻⁷ / ° C., particularly preferably 5 × 10 ⁻⁷ / ° C. or less. If the difference between these thermal expansion coefficients is too large, the stress remaining in the sealed portion is unduly high, and the long-term reliability of the hermetic package may be reduced.

In the method for manufacturing an airtight package of the present invention, the sealing material layer (the first sealing material layer and / or the second sealing material layer) is preferably formed by applying and sintering a sealing material paste. . In this way, the dimensional accuracy of the sealing material layer can be increased. Here, the sealing material paste is a mixture of a sealing material and a vehicle. The vehicle usually contains a solvent and a resin. The resin is added for the purpose of adjusting the viscosity of the paste. Moreover, surfactant, a thickener, etc. can also be added as needed. The produced sealing material paste is applied to the surface of the ceramic substrate or the glass lid using an applicator such as a dispenser or a screen printer.

The sealing material paste is preferably applied in a frame shape along the top of the frame portion of the ceramic substrate, and is preferably applied in a frame shape along the outer peripheral edge region of the glass lid. In this way, the space for accommodating the internal element can be expanded in the hermetic package.

The sealing material paste is preferably applied on the center line in the width direction at the top of the frame portion of the ceramic substrate. In this way, heat conduction to the ceramic substrate side during laser sealing can be made uniform.

The sealing material paste is usually produced by kneading the sealing material and the vehicle with a three-roller or the like. A vehicle usually includes a resin and a solvent. As the resin used for the vehicle, acrylic ester (acrylic resin), ethyl cellulose, polyethylene glycol derivative, nitrocellulose, polymethylstyrene, polyethylene carbonate, polypropylene carbonate, methacrylic ester and the like can be used. Solvents used in vehicles include N, N′-dimethylformamide (DMF), α-terpineol, higher alcohol, γ-butyllactone (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, 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, dimethyl sulfoxide (DM O), N-methyl-2-pyrrolidone and the like can be used.

Various glass can be used as the glass lid. For example, alkali-free glass, borosilicate glass, and soda lime glass can be used.

The thickness of the glass lid is preferably 0.01 to 2.0 mm, 0.1 to 1 mm, particularly preferably 0.2 to 0.7 mm. Thereby, thickness reduction of an airtight package can be achieved.

A functional film may be formed on the surface of the glass lid on the inner element side, or a functional film may be formed on the outer surface of the glass lid. In particular, an antireflection film is preferable as the functional film. Thereby, the light reflected on the surface of the glass lid can be reduced.

The glass lid is preferably a glass plate laminate in which the first glass plate and the second glass plate are laminated and integrated via an adhesive.

Various glasses can be used for the first glass plate and the second glass plate. For example, alkali-free glass, alkali borosilicate glass, and soda lime glass can be used. In addition, although it is preferable that a glass plate laminated body is comprised with two glass plates, you may laminate | stack another plate-shaped body further as needed.

The same glass may be used for the first glass plate and the second glass plate. That is, you may have the same glass composition. In this way, since various characteristics such as the refractive index and the thermal expansion coefficient of the two coincide, it is possible to suppress the warpage of the glass lid, the reflection on the bonding surface, and the like.

Also, different glasses may be used for the first glass plate and the second glass plate. That is, you may have a different glass composition. In this way, the thermal expansion coefficient of the second glass plate is not restricted by the thermal expansion coefficient of the ceramic substrate, so that the thermal expansion coefficient of the ceramic substrate and the first glass plate are closely matched, and productivity is improved. A good glass plate can be used for the second glass plate. As a result, it becomes easy to achieve both the airtight reliability of the airtight package and the production cost.

Various materials can be used as the adhesive for laminating the first glass plate and the second glass plate, but it is possible to use a photo-curing adhesive or a thermo-curing adhesive having excellent light transmittance. preferable. The thickness of the adhesive is preferably less than 500 μm, particularly preferably less than 100 μm. If the thickness of the adhesive is too thick, the transparency of the glass lid tends to be lowered.

The refractive index nd of the adhesive is preferably within the range of the refractive index nd ± 0.1 of the first glass plate, and preferably within the range of the refractive index nd ± 0.1 of the second glass plate. preferable. If the refractive index nd of the adhesive is inconsistent with the refractive index nd of the first glass plate and the refractive index nd of the second glass plate, the interface between the adhesive and the first glass plate, the adhesive and the second Light is easily reflected at the interface of the glass plate. For the same reason, the refractive index nd of the first glass plate is preferably in the range of the refractive index nd ± 0.1 of the second glass plate.

The manufacturing method of the hermetic package of the present invention includes a step of laminating and arranging the ceramic base and the glass lid so that the first sealing material layer and the second sealing material layer are in contact with each other. In this case, the glass lid may be disposed below the ceramic substrate, but it is preferable to dispose the glass lid above the ceramic substrate from the viewpoint of laser sealing efficiency.

When laminating and arranging the ceramic base and the glass lid, the first sealing material layer and the second sealing material layer are arranged so that the center lines in the width direction of the first sealing material layer and the second sealing material layer overlap each other. It is preferable to arrange the sealing material layer in contact. In this way, the accuracy of laser sealing can be increased.

The manufacturing method of the hermetic package of the present invention includes a first sealing material layer formed by irradiating a laser beam from the glass lid side and softening and deforming the first sealing material layer and the second sealing material layer. A step of hermetically sealing the second sealing material layer to obtain an airtight package;

Various lasers can be used as the laser. In particular, a semiconductor laser, a YAG laser, a CO ₂ laser, an excimer laser, and an infrared laser are preferable in terms of easy handling.

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

When performing laser sealing, if the glass lid is preheated at a temperature of 100 ° C. or higher and not higher than the heat resistant temperature of the light emitting element inside the substrate, cracking of the glass lid due to thermal shock can be suppressed. Moreover, if an annealing laser is irradiated from the glass lid side immediately after laser sealing, it is possible to suppress breakage of the glass lid due to thermal shock.

When performing laser sealing, if the ceramic substrate is preheated at a temperature of 100 ° C. or higher and not higher than the heat resistant temperature of the light emitting element inside the substrate, heat conduction to the ceramic substrate side may be hindered during laser sealing. Laser sealing can be performed efficiently.

It is preferable to perform laser sealing while pressing the glass lid. Thereby, the softening deformation of the sealing material layer can be promoted at the time of laser sealing.

The hermetic package of the present invention is an airtight package having a ceramic base and a glass lid, the ceramic base having a base and a frame provided on the base, and at least bismuth on the top of the frame of the ceramic base. A first sealing material layer containing glass is formed, a second sealing material layer containing at least bismuth glass is formed on the glass lid, and the first sealing material layer and The second sealing material layer is hermetically integrated in a state of contact arrangement. Since the technical features of the hermetic package of the present invention have already been described in the explanation column of the method of manufacturing the hermetic package of the present invention, detailed description thereof will be omitted for the sake of convenience.

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a conceptual cross-sectional view for explaining an embodiment of the present invention. The hermetic package 1 includes a ceramic base 10 and a glass lid 11. The ceramic substrate 10 has a base portion 12 and further has a frame portion 13 on the outer peripheral edge of the base portion 12. Further, the internal element 14 is accommodated in the frame portion 13 of the ceramic base 10. A first sealing material layer 16 is formed on the top portion 15 of the frame portion 13. The surface of the first sealing material layer 16 is polished in advance, and the surface roughness Ra is 0.15 μm or less. The width of the first sealing material layer 16 is slightly smaller than the width of the frame portion 13. Further, the first sealing material layer 16 is obtained by sintering a sealing material, and the sealing material includes a bismuth glass containing a transition metal oxide in a glass composition and a refractory filler powder. Contains. An electrical wiring (not shown) that electrically connects the internal element 14 and the outside is formed in the ceramic substrate 10.

A frame-shaped second sealing material layer 17 is formed on the surface of the glass lid 11. The second sealing material layer 17 is obtained by sintering the sealing material, and has substantially the same material configuration as that of the first sealing material layer 16, and the sealing material changes during the glass composition. It contains bismuth glass containing metal oxide and refractory filler powder. The width of the second sealing material layer 17 is substantially the same as the width of the first sealing material layer 16. Furthermore, the thickness of the second sealing material layer 17 is slightly smaller than the thickness of the first sealing material layer 16.

The ceramic substrate 10 and the glass lid 11 are laminated so that the glass lid 11 is on top and the center lines in the width direction of the first sealing material layer 16 and the second sealing material layer 17 are in contact with each other. Has been. Thereafter, the laser beam L emitted from the laser irradiation device 18 is irradiated along the first sealing material layer 16 and the second sealing material layer 17 from the glass lid 11 side. Thereby, after the first sealing material layer 16 and the second sealing material layer 17 are softened and flowed, the ceramic base 10 and the glass lid 11 are hermetically sealed, and the hermetic structure of the hermetic package 1 is formed. .

Hereinafter, the present invention will be described in detail based on examples. The following examples are merely illustrative. The present invention is not limited to the following examples.

First, a sealing material A was prepared by mixing bismuth-based glass powder at a ratio of 73% by volume and refractory filler powder at a rate of 27% by volume. Here, the average particle diameter D ₅₀ of the bismuth-based glass powder is 1.0 μm, the 99% particle diameter D ₉₉ is 2.5 μm, and the average particle diameter D ₅₀ of the refractory filler powder is 1.0 μm, 99% particle diameter D. ₉₉ was 2.5 μm. The bismuth-based glass has a glass composition of mol%, Bi ₂ O ₃ 39%, B ₂ O ₃ 23.7%, ZnO 14.1%, Al ₂ O ₃ 2.7%, CuO 20%, Fe ₂ O ₃ 0.6% is contained. The refractory filler powder is β-eucryptite.

When the thermal expansion coefficient of the obtained sealing material A was measured, the thermal expansion coefficient was 70 × 10 ⁻⁷ / ° C. The thermal expansion coefficient was measured with a push rod type TMA apparatus, and the measurement temperature range was 30 to 300 ° C.

Next, 65% by volume of silver phosphate glass powder and 35% by volume of refractory filler powder were mixed to prepare sealing material B. Here, 1.0 .mu.m average particle diameter _{D 50} of the silver phosphate glass powder, 99% particle diameter _{D 99} and 2.5 [mu] m, 1.0 .mu.m average particle diameter _{D 50} of the refractory filler powder, 99% particle the diameter _{D 99} was 2.5 [mu] m. The silver phosphate glass has a glass composition of mol%, Ag ₂ O 32%, P ₂ O ₅ 22%, TeO ₂ 27%, ZnO 11%, Nb ₂ O ₅ 3%, CuO 5%. Contains. The refractory filler powder is NbZr (PO ₄ ) ₃ .

When the thermal expansion coefficient of the obtained sealing material B was measured, the thermal expansion coefficient was 77 × 10 ⁻⁷ / ° C. The thermal expansion coefficient was measured with a push rod type TMA apparatus, and the measurement temperature range was 30 to 150 ° C.

Furthermore, 69% by volume of tellurium glass powder and 31% by volume of refractory filler powder were mixed to prepare sealing material C. Here, the average particle diameter D ₅₀ of the tellurium-based glass powder is 1.0 μm, the 99% particle diameter D ₉₉ is 2.5 μm, and the average particle diameter D ₅₀ of the refractory filler powder is 1.0 μm, 99% particle diameter D. ₉₉ was 2.5 μm. In addition, the tellurium type glass contains TeO ₂ 72%, Nb ₂ O ₅ 8%, and CuO 20% as a glass composition. The refractory filler powder is Zr ₂ (WO ₄ ) (PO ₄ ) ₂ .

When the thermal expansion coefficient of the obtained sealing material C was measured, the thermal expansion coefficient was 74 × 10 ⁻⁷ / ° C. The thermal expansion coefficient was measured with a push rod type TMA apparatus, and the temperature range for measurement was 30 to 250 ° C.

Next, using the sealing material described in the table, a ceramic substrate having a frame portion as shown in FIG. 1 (length 30 mm × width 30 mm × base thickness 0.8 mm, thermal expansion coefficient 70 × 10 ⁻⁷ / ° C. The first sealing material layer was formed on the top of the frame part. The ceramic substrate is composed of the materials shown in the table, and the frame portion has a frame shape with a width of 2 mm and a height of 1.0 mm. In addition, a second sealing material layer was formed along the outer peripheral edge of the glass lid (length 30 mm × width 30 mm) described in the table using the sealing material described in the table. In the table, “alkali borosilicate glass” is BDA manufactured by Nippon Electric Glass, “non-alkali glass” is OA-10G manufactured by Nippon Electric Glass, and “soda lime glass” is a commercially available window glass. . “Glass ceramic” is obtained by sintering a laminated sheet of green sheets containing glass powder and refractory filler powder.

In detail, first, after kneading the sealing material, vehicle, and solvent described in the table so that the viscosity is about 120 Pa · s (25 ° C., Shear rate: 4), the powder is further uniform in a three-roll mill. Kneaded until dispersed into a paste to obtain a sealing material paste. Next, the above-mentioned sealing material paste was printed in a frame shape on the top of the frame portion of the ceramic substrate by a screen printer. Similarly, the sealing material paste was printed in a frame shape by a screen printer along the outer peripheral edge of the glass lid. Furthermore, after drying at 120 ° C. for 10 minutes in an air atmosphere, firing at 500 ° C. for 10 minutes in an air atmosphere, a first sealing material layer having an average thickness of 6.0 μm and an average width of 500 μm, and A second sealing material layer was formed.

Finally, after placing the first sealing material layer formed on the top of the frame portion of the ceramic base and the second sealing material layer formed on the glass lid, the glass lid side has a wavelength of 808 nm and an output of 8 to 8 By irradiating a 32 W semiconductor laser to soften and deform the first sealing material layer and the second sealing material layer, the ceramic base and the glass lid were hermetically sealed to obtain each hermetic package.

The obtained airtight package was evaluated for cracks and airtight reliability after laser sealing. The crack after laser sealing is evaluated by observing the sealed portion with an optical microscope as “◯” when there is no crack and “×” when there is a crack.

Next, the airtight reliability of the obtained airtight package was evaluated by a temperature cycle test. More specifically, after the temperature cycle test was performed on the obtained airtight package, the vicinity of the sealing material layer was observed, and no change, cracking, peeling, or the like was observed. Airtight reliability was evaluated as “x” when alteration, cracking, peeling, or the like was observed. The conditions of the temperature cycle test are 125 ° C. to 55 ° C. and 1000 cycles.

Next, the airtight reliability of the obtained airtight package was evaluated by a high-temperature, high-humidity and high-pressure test: HAST (Highly Accelerated Temperature and Humidity Stress test). Specifically, after the HAST was performed on the obtained airtight package, the vicinity of the sealing material layer was observed, and “O”, alteration, Airtight reliability was evaluated as “x” when cracks, peeling, etc. were observed. The HAST test conditions are 121 ° C., humidity 100%, 2 atm, and 24 hours.

As is clear from Tables 1 to 3, sample No. For Nos. 1-4, 8, 9, 12, and 13, the evaluation of cracks after laser sealing and the evaluation of hermetic reliability were good. On the other hand, sample No. In Nos. 5 to 7, 10, 11, 14, and 15, since the first sealing material layer is not formed on the ceramic substrate, the laser output is increased to the value in the table, and the surface layer of the ceramic substrate and the second layer It was necessary to react the sealing material layer. As a result, sample no. In Nos. 5 to 7, 10, 11, 14, and 15, cracks occurred after laser sealing, and the hermetic reliability of the hermetic package was low. Sample No. As for 5 to 7, 10, 11, 14, and 15, when the laser output is lowered at the time of laser sealing, the laser sealing strength is lowered, and the evaluation of airtight reliability becomes poor.

The hermetic package of the present invention is suitable for an airtight package in which internal elements such as a sensor chip and an LED are mounted, but also accommodates a piezoelectric vibration element or a wavelength conversion element in which quantum dots are dispersed in a resin. It can be suitably applied to an airtight package or the like.

DESCRIPTION OF SYMBOLS 1 Airtight package 10 Ceramic base | substrate 11 Glass cover 12 Base part 13 Frame part 14 Internal element 15 Top part 16 of a frame part 1st sealing material layer 17 2nd sealing material layer 18 Laser irradiation apparatus L Laser beam

Claims

Preparing a ceramic substrate and forming a first sealing material layer on the ceramic substrate;
Preparing a glass lid and forming a second sealing material layer on the glass lid;
Laminating and arranging the ceramic base and the glass lid so that the first sealing material layer and the second sealing material layer are in contact with each other;
The first sealing material layer and the second sealing material layer are hermetically sealed by irradiating laser light from the glass lid side and softening and deforming the first sealing material layer and the second sealing material layer. And a step for obtaining an airtight package.
The first sealing material layer contains at least one of bismuth glass, silver phosphate glass, and tellurium glass, and the second sealing material layer includes bismuth glass and silver phosphate glass. The method for producing an airtight package according to claim 1, comprising at least one of tellurium-based glass.
The average thickness of the first sealing material layer is less than 8.0 μm, the average thickness of the second sealing material layer is less than 8.0 μm, and the average thickness of the first sealing material layer and the second sealing material The method for manufacturing an airtight package according to claim 1 or 2, wherein the total average thickness of the layers is restricted to less than 15.0 µm.
The hermetic package according to any one of claims 1 to 3, wherein the average width of the first sealing material layer is regulated to less than 2000 µm, and the average width of the second sealing material layer is regulated to less than 2000 µm. Production method.
The hermetic seal according to any one of claims 1 to 4, wherein a ceramic base having a base and a frame provided on the base is used, and a first sealing material layer is formed on the top of the frame. Package manufacturing method.
The method for producing an airtight package according to any one of claims 1 to 5, further comprising a step of polishing the surface of the first sealing material layer.
The method for producing an airtight package according to any one of claims 1 to 6, wherein the ceramic substrate is one of glass ceramic, aluminum nitride, aluminum oxide, or a composite material thereof.
The method for manufacturing an airtight package according to any one of claims 1 to 7, wherein the sensor element or the LED element is accommodated in a frame portion of the ceramic substrate.
In an airtight package having a ceramic substrate and a glass lid,
The ceramic base has a base and a frame provided on the base,
A first sealing material layer containing one or more of bismuth-based glass, silver phosphate-based glass, and tellurium-based glass is formed on the top of the frame portion of the ceramic substrate,
On the glass lid, a second sealing material layer containing at least one of bismuth glass, silver phosphate glass, and tellurium glass is formed,
A hermetic package, wherein the first sealing material layer and the second sealing material layer are hermetically integrated in a state of being in contact with each other.
The first sealing material layer contains bismuth glass containing transition metal oxide in the glass composition, and the second sealing material layer contains bismuth glass containing transition metal oxide in the glass composition. The hermetic package according to claim 10, which is contained.
The average thickness of the first sealing material layer is less than 8.0 μm, the average thickness of the second sealing material layer is less than 8.0 μm, and the average thickness of the first sealing material layer and the second 11. The airtight package according to claim 9, wherein the total thickness of the sealing material layers is less than 15.0 μm.
12. The hermetic package according to claim 9, wherein the average width of the first sealing material layer is less than 2000 μm, and the average width of the second sealing material layer is less than 2000 μm. .
The hermetic package according to any one of claims 9 to 12, wherein the ceramic substrate is one of glass ceramic, aluminum nitride, aluminum oxide, or a composite material thereof.
14. The hermetic package according to claim 9, wherein a sensor element or an LED element is accommodated in the frame portion of the ceramic substrate.