TW201901866A - Method for manufacturing hermetic package and hermetic package - Google Patents

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

Manufacturing method of hermetically sealed body and hermetically sealed body

The present invention relates to a method of manufacturing a gas-tight package and a gas-tight package, in particular, to a gas-tight seal between a ceramic substrate and a glass cover through a sealing process using laser light (hereinafter referred to as a laser seal) A manufacturing method of a sealed package and a gas-sealed package manufactured by this method.

The gas-tight package generally includes a ceramic base, a light-transmissive glass cover, and internal components housed in these.

Internal elements such as a sensor wafer mounted inside the airtight package may deteriorate due to moisture immersed from the surrounding environment. To date, in order to integrate the ceramic substrate and the glass cover, an organic resin-based adhesive having low-temperature hardening properties has been used. However, organic resin-based adhesives cannot completely shield moisture and gas, so there is a possibility of deteriorating internal components over time.

On the other hand, when a sealing material containing glass powder and refractory filler powder is used, the sealing portion is not easily deteriorated by moisture in the surrounding environment, and it is easy to ensure the airtight reliability of the airtight package.

However, the softening temperature of the glass powder is higher than that of the organic resin-based adhesive, so there is a possibility of thermally deteriorating internal components during sealing. Based on these circumstances, the laser seal has attracted attention in recent years. When sealing by laser, only the part to be sealed can be heated locally, and the ceramic substrate and the glass cover can be air-tightly integrated without thermally deteriorating internal components. [Prior Technical Literature] [Patent Literature]

[Patent Literature 1] Japanese Patent Application Publication No. 2013-239609 [Patent Literature 2] Japanese Patent Application Publication No. 2014-236202

[Problems to be solved by the invention]

In addition, in the case of laser sealing the ceramic substrate and the glass cover, the thermal conductivity of the ceramic substrate is higher than in the case of laser sealing the glass substrate and the glass cover, and the temperature of the ceramic substrate during laser sealing is unlikely to rise Therefore, the sealing material layer does not easily react with the ceramic substrate, and there is such a problem that it is difficult to ensure the laser sealing strength.

On the other hand, when the output of laser light is increased, although the reactivity of the sealing material layer and the ceramic substrate can be improved, in this case, the portion of the glass cover that is in contact with the locally heated sealing material layer and the partially unheated portion A large temperature difference occurs, so the glass cover is easily damaged by thermal shock, and there is a problem that the airtight reliability of the airtight package cannot be ensured.

Therefore, the present invention was created in view of the above circumstances, and its technical subject is to invent a method of manufacturing a hermetically sealed body, which can make the laser sealing strength and airtight when the ceramic substrate and the glass cover are laser sealed Reliability is established at a high level at the same time. [Technical means to solve the problem]

As a result of a keen review of the inventors, the inventors found that the above technical problems can be solved under the following circumstances and therefore proposed the present invention: after forming the first sealing material layer on the ceramic substrate and forming the second sealing material layer on the glass cover, after making the first Laser sealing is performed in a state where the sealing material layer is in contact with the second sealing material layer. That is, the manufacturing method of the gas-tight package of the present invention includes the following procedures: preparing a ceramic substrate and forming a first sealing material layer on the ceramic substrate; preparing a glass cover and forming a second sealing material layer on the glass cover; The first sealing material layer is in contact with the second sealing material layer, and the ceramic substrate and the glass cover are laminated; the laser light is irradiated from the glass cover side to soften and deform 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 obtain an airtight package.

The manufacturing method of the gas-tight package of the present invention is to form a first sealing material layer on a ceramic substrate and a second sealing material layer on a glass cover, and then make the first sealing material layer contact with the second sealing material layer Perform laser sealing. In this case, before the laser sealing, a sealing material layer is formed on the ceramic substrate and the glass cover by electric furnace firing, etc., so a strong reaction layer can be formed on the surface layer of the ceramic substrate, and a strong layer can also be formed on the surface layer of the glass cover Of the reaction layer. In addition, during laser sealing, both the first sealing material layer and the second sealing material layer soften and flow to fuse, so it is easy to integrate the ceramic substrate and the glass cover in an airtight manner. Furthermore, the local heating temperature during laser sealing can be lowered, so that not only the glass cover is not easily damaged by thermal shock, but also the heat transmitted to the internal components due to thermal conduction can be reduced. As a result, the laser sealing strength and airtight reliability of the airtight package can be improved at the same time, and the thermal degradation of internal components can be prevented.

In addition, the method for manufacturing the gas-tight package of the present invention is preferably that the first sealing material layer contains any one or more of bismuth glass, silver phosphate glass, and tellurium glass, and the second sealing material layer contains bismuth glass , Any one or more of silver phosphate-based glass and tellurium-based glass. Bismuth-based glass, especially bismuth-based glass containing transition metal oxides in the glass composition, has a characteristic that it is easier to form a reaction layer on the surface layer of the ceramic substrate when laser sealing. In addition, when the refractory filler powder is introduced, the mechanical strength of the sealing material layer can be improved, and the coefficient of thermal expansion of the sealing material layer can be reduced. Compared with bismuth glass, silver phosphate glass and tellurium glass are easy to soften and flow at low temperature, which can reduce the thermal strain after laser sealing, so it has the characteristics of improving thermal reliability and mechanical reliability. Furthermore, silver phosphate-based glass and tellurium-based glass are similar to bismuth-based glass. When the refractory filler powder is mixed, the mechanical strength of the sealing material layer can be improved, and the thermal expansion coefficient of the sealing material layer can be reduced. Here, "bismuth-based glass" refers to a glass containing Bi ₂ O ₃ as a main component, and specifically refers to a glass containing Bi ₂ O ₃ of 25 mol% or less in the glass composition. "Silver phosphate-based glass" refers to glass containing Ag ₂ O and P ₂ O ₅ as the main components, specifically, glass containing 25 mol% or more of Ag ₂ O and P ₂ O ₅ in the total amount of the glass composition . "Tellurium-based glass" refers to glass containing TeO ₂ as a main component, and specifically refers to glass containing TeO ₂ in an amount of 20 mol% or more in the glass composition.

In addition, the method of manufacturing the gas-tight package of the present invention preferably limits the average thickness of the first sealing material layer to less than 8.0 μm, limits the average thickness of the second sealing material layer to less than 8.0 μm, and limits the first The total thickness of the average thickness of the sealing material layer and the average thickness of the second sealing material layer is limited to less than 15.0 μm. In this case, the residual stress in the air-tight package after laser sealing can be reduced, so the air-tight reliability of the air-tight package can be improved.

In addition, the method of manufacturing the gas-sealed package of the present invention preferably limits the average width of the first sealing material layer to less than 2000 μm, and limits the average width of the second sealing material layer to less than 2000 μm. In this case, the residual stress in the air-tight package after laser sealing can be reduced, so the air-tight reliability of the air-tight package can be improved.

In addition, in the method for manufacturing the hermetically sealed package of the present invention, preferably, a ceramic base having a base portion and a frame portion provided on the base portion is used to form a first sealing material layer on top of the frame portion.

In addition, the method for manufacturing the airtight package of the present invention is preferably further provided with a procedure for polishing the surface of the first sealing material layer.

In addition, the method for manufacturing the gas-tight package of the present invention is preferably that the ceramic substrate is any one of glass ceramics, aluminum nitride, and aluminum oxide, or a composite material of these.

In addition, the method of manufacturing the hermetically sealed package of the present invention is preferably such that the sensor element or the LED element is accommodated in the frame portion of the ceramic base.

The gas-tight package system of the present invention is a gas-tight package having a ceramic base and a glass cover. The ceramic base has a base and a frame provided on the base. On the top of the frame of the ceramic base, a glass containing bismuth and phosphoric acid A first sealing material layer of any one or more of silver-based glass and tellurium-based glass, a second sealing material layer containing any one or more of bismuth-based glass, silver phosphate-based glass, and tellurium-based glass is formed on the glass cover, and It is hermetically integrated in a state where the first sealing material layer and the second sealing material layer are arranged in contact.

In addition, in the gas seal system of the present invention, preferably, the first sealing material layer contains bismuth-based glass containing a transition metal oxide in the glass composition, and the second sealing material layer contains bismuth containing a transition metal oxide in the glass composition Department of glass.

In addition, in the gas seal system of the present invention, preferably, 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 total average thickness of the layers is less than 15.0 μm.

In addition, in the hermetic package system 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 addition, in the gas-tight packaging system of the present invention, preferably, the ceramic substrate is any one of glass ceramics, aluminum nitride, and aluminum oxide, or a composite material of these.

In addition, in the hermetic package system of the present invention, preferably, the sensor element or the LED element is housed in the frame portion of the ceramic base.

The manufacturing method of the airtight package of the present invention has the following procedures: preparing a ceramic base and forming a first sealing material layer on the ceramic base; preparing a glass cover and forming a second sealing material layer on the glass cover.

The ceramic base preferably has a base and a frame provided on the base. In this case, it is easy to house internal components such as sensor wafers in the space within the ceramic base. The frame portion of the upper ceramic base is preferably formed in a frame shape along the outer peripheral edge region of the ceramic base. When this is done, the effective area that functions as a device can be increased. It is easier to house internal components such as sensor wafers in the frame portion of the ceramic base, and it is also easier to perform wire bonding and the like.

It is preferable that the surface roughness Ra of the surface of the region where the sealing material layer is arranged on the top of the frame portion is less than 1.0 μm. As the surface roughness Ra of this surface becomes larger, the accuracy of the laser seal tends to decrease. Here, the "surface roughness Ra" can be measured by, for example, a stylus-type or non-contact laser film thickness meter or a surface roughness meter.

The ceramic substrate is preferably composed of any one of glass ceramics, aluminum nitride, and aluminum oxide, or a composite material thereof (for example, an aluminum nitride and glass ceramic are integrated). The glass ceramic can easily form a heat conduction hole, so it can appropriately prevent the overheating of the airtight package during the operation of the internal components. Aluminum nitride and aluminum oxide have good heat dissipation, so it is possible to appropriately prevent the overheating of the airtight package during the operation of internal components.

Glass ceramics, aluminum nitride, and aluminum oxide can also be dispersed with black pigments. When this is done, the ceramic substrate can absorb the laser light penetrating the sealing material layer. As a result, the heat flow to the ceramic base with high thermal conductivity can be reduced during laser sealing, so that laser sealing can be performed efficiently.

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

The thickness of the base of the ceramic base is preferably 0.1 to 2.5 mm, especially 0.2 to 1.5 mm. This makes it possible to reduce the thickness of the airtight package.

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, especially 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, particularly less than 12.0 μm. The smaller the average thickness of the sealing material layer, even if the thermal expansion coefficients of the sealing material layer, the ceramic substrate and the glass cover are not integrated, the stress remaining in the sealing portion after laser sealing can still be reduced. In addition, the accuracy of laser sealing can also be improved. In addition, as the method of limiting the average thickness of the sealing material layer as described above, a method of applying a thin sealing material paste and a method of polishing the surface of the sealing material layer are exemplified.

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, especially 200 μm or more and less than 800 μm. When the average width of the sealing material layer is narrow, the stress remaining in the sealing portion after laser sealing can be reduced. In addition, the width of the frame portion of the ceramic base can be narrowed, and the effective area of the airtight package functioning as a device can be increased.

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, 0.2 μm or less, especially 0.01 to 0.15 μm. When this is done, the adhesion between the first sealing material layer and the second sealing material layer is improved, and the accuracy of the laser sealing is improved. Here, the "surface roughness Ra" can be measured by, for example, a stylus-type or non-contact laser film thickness meter or a surface roughness meter. In addition, as the method of restricting the surface roughness Ra of the sealing material layer as described above, a method of polishing the surface of the sealing material layer and a method of reducing the particle size of the refractory filler powder contained in the sealing material layer are exemplified.

The first sealing material layer and the second sealing material layer may be made of the same material, or may contain glass powder having the same glass composition. In this case, the behavior of the first sealing material layer and the second sealing material layer, such as the fluidity and the coefficient of thermal expansion, becomes the same, so that it is easy to control the laser sealing process.

The first sealing material layer and the second sealing material layer may be made of different materials, and may also contain glass powder with different glass compositions. In this case, the thermal expansion coefficients of the first sealing material layer and the second sealing material layer can be adjusted individually, so it is easy to optimize the thermal expansion coefficients between the first sealing material layer, the second sealing material layer, the ceramic substrate and the glass cover . As a result, it is easy to prevent breakage of the glass cover or the like after laser sealing.

The sealing material layer is a sintered body of sealing material, which is softened and deformed during laser sealing. For the sealing material, various glasses (for example, bismuth-based glass, silver phosphate-based glass, tellurium-based glass, tin phosphate-based glass, vanadium-based glass, etc.) can be used, especially from the viewpoint of ensuring the laser sealing strength Glass containing 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, especially 15 to 30 mol in order to improve the laser absorption characteristics %.

In terms of bismuth-based glass composition, it is preferable to contain 28 to 60% of Bi ₂ O ₃ , 15 to 37% of B ₂ O ₃ , 1 to 30% of ZnO, and 0 to 40% of transition metals in mole% Oxide. In addition, in the description of the glass composition range of bismuth-based glass,% means mole%.

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%, and especially 35% to 45%. When 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, when the content of Bi ₂ O ₃ is too large, the glass is likely to devitrify during laser sealing, and the fluidity is easily degraded by this and thus reduced.

The B ₂ O ₃ system is an essential component in terms of glass forming components, and the content thereof is preferably 15 to 37%, 20 to 33%, and especially 25 to 30%. When the content of B ₂ O ₃ is too small, it is difficult to form a glass network, so the glass is easily devitrified during laser sealing. On the other hand, if the content of B ₂ O ₃ is too large, the viscosity of the glass becomes high, and the fluidity tends to decrease.

The content of ZnO-based devitrification-improving component is preferably 1 to 30%, 3 to 25%, 5 to 22%, and especially 9 to 20%. When the content of ZnO is outside the above range, the composition balance of the glass composition is impaired, and the devitrification resistance tends to decrease.

The transition metal oxide has a component with laser absorption characteristics, and its content is preferably 0-40%, 1-40%, 3-40%, 5-40%, 12-40%, especially 15-30 mole% . When the content of the transition metal oxide is too large, the devitrification resistance tends to decrease.

When CuO is added, the laser absorption characteristics can be improved. The content of CuO is preferably 0 to 40%, 5 to 35%, 10 to 30%, especially 15 to 25%. When the content of CuO is too large, the composition balance of the glass composition is impaired, and devitrification resistance tends to decrease. In addition, to reduce 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, when the content of Bi ₂ O ₃ is increased, the glass is easily devitrified during laser sealing, and the fluidity is easy Reduced devitrification. In particular, when the content of Bi ₂ O ₃ becomes 30% or more, this tendency becomes remarkable. For this countermeasure, when CuO is added, even if the content of Bi ₂ O ₃ is 30% or more, devitrification of the glass can be effectively suppressed.

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

MnO is a component that improves laser absorption characteristics. The content of MnO is preferably 0 to 25%, especially 5 to 15%. When the content of MnO is too large, the devitrification resistance tends to decrease.

MoO ₃ is a component that improves laser absorption characteristics. The content of MoO ₃ is preferably 0 to 25%, especially 5 to 15%. When the content of MoO ₃ is too large, the 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 improves water resistance, but has the effect of increasing the softening point. For this reason, the content of SiO ₂ is preferably 0 to 5%, 0 to 3%, 0 to 2%, especially 0 to 1%. In addition, when the content of SiO ₂ is too large, the glass is easily devitrified during laser sealing.

The Al ₂ O ₃ system is a component that improves water resistance, and its content is preferably 0 to 10%, 0 to 5%, and particularly 0.1 to 2%. If the content of Al ₂ O ₃ is too large, the softening point may increase inappropriately.

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

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

Sb ₂ O ₃ is a component for improving devitrification resistance, and the content thereof is preferably 0 to 5%, especially 0 to 2%. When the content of Sb ₂ O ₃ is too large, the composition balance of the glass composition is impaired, and devitrification resistance tends to decrease.

In terms of silver phosphate-based glass composition, it is preferable to contain 10 to 50% of Ag ₂ O, 10 to 35% of P ₂ O ₅ , 3 to 25% of ZnO, and 0 to 30% transition in mole%. Metal oxide. In addition, in the description of the glass composition range of the silver phosphate-based glass,% means mole%.

The Ag ₂ O system lowers the melting point of glass and is difficult to dissolve in water, so it is a component that improves water resistance. The content of Ag ₂ O is preferably 10-50%, especially 20-40%. When the content of Ag ₂ O is too small, the viscosity of the glass becomes high, the fluidity tends to decrease, and the water resistance tends to decrease. On the other hand, when the content of Ag ₂ O is too large, vitrification becomes difficult.

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

The content of the ZnO-based devitrification-improving component is preferably 3 to 25%, 5 to 22%, and especially 9 to 20%. When the content of ZnO is outside the above range, the composition balance of the glass composition is impaired, and the devitrification resistance tends to decrease.

The transition metal oxide-based component has laser absorption characteristics, and its content is preferably 0 to 30%, 1 to 30%, and particularly 3 to 15%. When the content of the transition metal oxide is too large, the devitrification resistance tends to decrease.

When CuO is added, the laser absorption characteristics can be improved. The content of CuO is preferably 0 to 30%, 1 to 30%, especially 3 to 15%. When the content of CuO is too large, the composition balance of the glass composition is impaired, and devitrification resistance tends to decrease.

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

TeO ₂ -based glass forming component is a component that lowers the melting point of glass. The content of TeO ₂ is preferably 0 to 40%, especially 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%, especially 1 to 12%. When the content of Nb ₂ O ₅ is too large, the viscosity of the glass becomes high, and the fluidity tends to decrease.

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

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

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

TeO ₂ -based glass forming component is a component that lowers the melting point of glass. The content of TeO ₂ is preferably 20 to 80%, especially 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%, especially 5 to 15%. When the content of Nb ₂ O ₅ is too large, the viscosity of the glass becomes high, and the fluidity tends to decrease.

The transition metal oxide-based component has laser absorption characteristics, and its content is preferably 0 to 40%, 5 to 30%, especially 15 to 25%. When the content of the transition metal oxide is too large, the devitrification resistance tends to decrease.

When CuO is added, the laser absorption characteristics can be improved. The content of CuO is preferably 0 to 40%, 5 to 30%, especially 15 to 25%. When the content of CuO is too large, the composition balance of the glass composition is impaired, and devitrification resistance tends to decrease.

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

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

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

The average particle diameter D _{50 of the} glass powder is preferably less than 15 μm, 0.5 to 10 μm, especially 0.8 to 5 μm. The smaller the average particle diameter D ₅₀ of the glass powder, the lower the softening point of the glass powder.

The sealing material layer (the first sealing material layer and / or the second sealing material layer) may also contain 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, more preferably contains 55 to 85% by volume of glass and 15 to 45% by volume of refractory filler powder, particularly preferably It contains 60 to 80% by volume of glass and 20 to 40% by volume of refractory filler powder. When the refractory filler powder is added, the thermal expansion coefficient of the sealing material is easily integrated with the thermal expansion coefficient of the ceramic substrate and glass cover. As a result, it is easy to prevent a situation where an undue stress remains on the sealing portion after laser sealing. On the other hand, when the content of the refractory filler powder is too large, the content of glass relatively decreases, so the surface smoothness of the sealing material layer decreases, and the accuracy of laser sealing tends to decrease.

For the refractory filler powder, one or two selected from cordierite, zircon, tin oxide, niobium oxide, zirconium phosphate-based ceramics, wurtzite, β-eucryptite, and β-quartz solid solution are preferably used. the above. These refractory filler powder systems have a low thermal expansion coefficient, high mechanical strength, and good compatibility with bismuth-based glass, silver phosphate-based glass, tellurium-based glass, and the like.

The average particle size D _{50 of the} refractory filler powder is preferably less than 2 μm, especially 0.1 μm or more and less than 1.5 μm. When the average particle size D _{50 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. As a result, the accuracy of laser sealing tends to decrease.

The 99% particle size D _{99 of the} refractory filler powder is preferably less than 5 μm, 4 μm or less, especially 0.3 μm or more and 3 μm or less. When 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. As a result, the accuracy of laser sealing tends to decrease. Here, "99% particle size D ₉₉ " refers to the value measured on a volume basis by the laser diffraction method. Herein, "average particle diameter D _50" and "99% particle diameter D _99" refers to the laser diffraction method was measured through a volume basis of the value.

The sealing material layer (the first sealing material layer and / or the second sealing material layer) may further include a laser absorber in order to improve the laser absorption characteristics, but the laser absorber has a function of promoting devitrification of the glass. Therefore, the content of the laser absorber 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, and preferably does not substantially contain it. In the case where the devitrification resistance of the glass is good, in order to improve the laser absorption characteristics, the laser absorption material may be introduced into 1 volume% or more, especially 3 volume% or more. For 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.

55 × 10 based on the thermal expansion coefficient of the sealing material layer (a first sealant layer and / or the second sealing material layer) is preferably ^{- 7 ~ 105 × 10 - 7} / ℃, 60 × 10 - 7 ~ 82 × 10 - 7 / ℃, in particular ^{65 × 10 - 7 ~ 76 ×} 10 - 7 / ℃. When this is done, the thermal expansion coefficient of the sealing material layer is integrated with the thermal expansion coefficients of the ceramic substrate and the glass cover, and the stress remaining in the sealing portion becomes smaller.

Thermal expansion coefficient of the sealing layer and the ceramic substrate difference is less than 65 × 10 on a preferably ^{- 7} / ℃, in particular 25 × 10 ^- on ⁷ / ℃ less, and the thermal expansion coefficient of the sealing layer and the glass cover is preferred that the difference is less than 75 × 10 ^{- 7} / ℃, in particular 25 × 10 ^{- 7} / ℃ less, furthermore a first coefficient of thermal expansion of the second sealing material layer and the sealing material layer is preferably the difference is less than 30 × 10 ^{- 7} / ℃, less than 10 × 10 ^{- 7} / ℃, in particular 5 × 10 ^- less ⁷ / ℃. If the difference in thermal expansion coefficient is too large, the stress remaining in the sealing portion will be unduly high, and the long-term reliability of the airtight package may decrease.

In the method of manufacturing the gas-tight 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 coating and sintering the sealing material paste. When this is done, the dimensional accuracy of the sealing material layer can be improved. Here, the sealing material paste is a mixture of the sealing material and the bonding agent. Then, the bonding agent generally contains a solvent and a resin. The resin system is added to adjust the viscosity of the paste. In addition, surfactants, tackifiers, etc. can also be added as appropriate. The produced sealing material paste is applied to the surface of the ceramic substrate and the glass cover using a dispenser 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 base, and preferably applied in a frame shape along the outer peripheral edge region of the glass cover. When this is done, it is possible to increase the space for accommodating the internal components in the airtight package.

The sealing material paste is preferably applied to the top of the frame of the ceramic substrate on the center line in the width direction. In this case, the thermal conductivity to the ceramic substrate side during laser sealing can be made uniform.

The sealing material paste is generally produced by kneading the sealing material and the bonding agent through three rollers or the like. The bonding agent generally contains a resin and a solvent. The resin used for the bonding agent can be used: acrylate (acrylic resin), ethyl cellulose, polyethylene glycol derivatives, nitrocellulose, polymethylstyrene, polyvinylpyrrolidone, polypropylene carbonate, methyl alcohol Based acrylate, etc. The solvent used in the bonding agent can be used: N, N'-dimethylformamide (DMF), α-terpineol, higher alcohol, γ-butyrolactone (γ-BL), tetralin, di Glycol butyl ether 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 (DMSO ), N-methyl-2-pyrrolidone, etc.

For the glass cover, various glasses can be used. For example, non-alkali glass, borosilicate glass, soda lime glass can be used.

The thickness of the glass cover is preferably 0.01 to 2.0 mm, 0.1 to 1 mm, especially 0.2 to 0.7 mm. This makes it possible to reduce the thickness of the airtight package.

A functional film may be formed on the surface of the glass cover on the side of the internal element, or a functional film may be formed on the surface of the outside of the glass cover. In particular, an anti-reflection film is preferable in terms of functional films. By this, the light reflected on the surface of the glass cover can be reduced.

In addition, the glass cover 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 glass can be used for the first glass plate and the second glass plate. For example, non-alkali glass, alkali borosilicate glass, soda lime glass can be used. In addition, although the glass plate laminate is preferably composed of two glass plates, another plate-like body may be further laminated as appropriate.

The same glass can be used for the first glass plate and the second glass plate. That is, it can have the same glass composition. In such a case, the various characteristics such as the refractive index and the coefficient of thermal expansion of the two are the same, so that the bending of the glass cover and the reflection on the bonding surface can be suppressed.

In addition, different types of glass can be used for the first glass plate and the second glass plate. That is, it can have different glass compositions. In this case, the thermal expansion coefficient of the second glass plate is not restricted by the thermal expansion coefficient of the ceramic substrate, so the thermal expansion coefficient of the ceramic substrate and the first glass plate can be tightly integrated while using a glass plate with good productivity Second glass plate. As a result, it is easy to establish the airtight reliability of the airtight package simultaneously with the production cost.

Various materials can be used for the adhesive for bonding the first glass plate and the second glass plate, but it is preferable to use a light-curing adhesive or a thermosetting adhesive that is excellent in light transmittance. Then, the thickness of the adhesive is preferably less than 500 μm, especially less than 100 μm. When the thickness of the adhesive is too thick, the transparency of the glass cover is easily reduced.

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. When the refractive index nd of the adhesive is not integrated with the refractive index nd of the first glass plate and the refractive index nd of the second glass plate, light is likely to be at the interface between the adhesive and the first glass plate and the interface between the adhesive and the second glass plate reflection. For the same reason, the refractive index nd of the first glass plate is preferably within the range of the refractive index nd ± 0.1 of the second glass plate.

The manufacturing method of the gas-tight package of the present invention has a procedure of laminating the ceramic substrate and the glass cover in such a manner that the first sealing material layer and the second sealing material layer are in contact. In this case, the glass cover may be arranged below the ceramic base, but from the viewpoint of the efficiency of laser sealing, it is preferable to arrange the glass cover above the ceramic base.

When laminating the ceramic substrate and the glass cover, it is preferable that the first sealing material layer and the second sealing material layer are stacked such that the center lines in the width direction of the first sealing material layer and the second sealing material layer overlap each other. Perform contact configuration. When this is done, the accuracy of the laser seal can be improved.

The manufacturing method of the airtight package of the present invention has the following procedure: irradiating laser light from the side of the glass cover to soften and deform the first sealing material layer and the second sealing material layer, thereby transforming the first sealing material layer and the second sealing material layer Airtight sealing is performed to obtain an airtight package.

For laser, various lasers can be used. In particular, semiconductor lasers, YAG lasers, CO ₂ lasers, excimer lasers, and infrared lasers are preferred because they are easy to handle.

The environment for laser sealing is not particularly limited, and it may be an atmospheric environment or an inert gas environment such as a nitrogen environment.

When performing laser sealing, when the glass cover is preheated at a temperature (100 ° C. or higher and below the heat-resistant temperature of the light-emitting element inside the substrate), cracking of the glass cover due to thermal shock can be suppressed. In addition, immediately after laser sealing, when the annealing laser is irradiated from the side of the glass cover, cracking of the glass cover due to thermal shock can be suppressed.

When performing laser sealing, when the ceramic substrate is preheated at a temperature (above 100 ° C and below the heat-resistant temperature of the light-emitting element inside the substrate), in order to hinder the heat conduction to the ceramic substrate side during laser sealing , Laser sealing can be performed efficiently.

It is preferable to perform laser sealing with the glass cover pressed. This can promote the softening and deformation of the sealing material layer during laser sealing.

The hermetically sealed package system of the present invention is provided in a hermetically sealed package having a ceramic base and a glass cover. The ceramic base has a base and a frame portion provided on the base. The first sealing material layer forms a second sealing material layer containing at least a bismuth glass on the glass cover, and is hermetically integrated in a state where the first sealing material layer and the second sealing material layer are arranged in contact. The technical features of the gas-tight package of the present invention have been described in the description column of the method of manufacturing the gas-tight package of the present invention, so for the sake of convenience of this part, detailed description is omitted.

Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional conceptual diagram for explaining an embodiment of the present invention. The airtight package 1 includes a ceramic base 10 and a glass cover 11. The ceramic base 10 has a base 12 and further has a frame 13 on the outer peripheral edge of the base 12. In addition, the internal element 14 is accommodated in the frame portion 13 of the ceramic base 10. Then, the first sealing material layer 16 is formed on the top 15 of the frame portion 13. The surface of the first sealing material layer 16 is previously polished, and its surface roughness Ra is 0.15 μm or less. Then, the width of the first sealing material layer 16 is slightly smaller than the width of the frame portion 13. Furthermore, the first sealing material layer 16 is a sintered sealing material containing bismuth glass containing a transition metal oxide in the glass composition and refractory filler powder. In addition, electrical wiring (not shown) electrically connecting the internal element 14 and the outside is formed in the ceramic base 10.

A frame-shaped second sealing material layer 17 is formed on the surface of the glass cover 11. The second sealing material layer 17 is a sintered sealing material, and is composed of the same material as the first sealing material layer 16. The sealing material contains bismuth glass containing a transition metal oxide in the glass composition and refractory filler powder. Then, the width of the second sealing material layer 17 is slightly 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 base 10 and the glass cover 11 are stacked so that the glass cover 11 is above 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. After that, the laser light 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 cover 11 side. As a result, 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 cover 11 are hermetically sealed to form an airtight structure of the hermetically sealed package 1. [Example]

Hereinafter, the present invention will be described in detail based on examples. In addition, the following embodiments are only examples. The present invention is not limited to the following examples at all.

First, the bismuth-based glass powder was 73% by volume and the refractory filler powder was 27% by volume, and a sealing material A was produced. Here, the average particle diameter D ₅₀ of the bismuth-based glass powder is 1.0 μm and the 99% particle diameter D ₉₉ is 2.5 μm, and the average particle size D ₅₀ of the refractory filler powder is 1.0 μm and 99% particle diameter D ₉₉ is 2.5μm. In addition, in terms of glass composition, bismuth glass contains 39% Bi ₂ O ₃ , 23.7% B ₂ O ₃ , 14.1% ZnO, 2.7% Al ₂ O ₃ , and 20% CuO in mole% , 0.6% Fe ₂ O ₃ . In addition, the refractory filler powder is β-eucryptite.

When the thermal expansion coefficient of the sealing material A obtained was measured, the coefficient of thermal expansion lines 70 × 10 ^{- 7} / ℃. In addition, the thermal expansion coefficient is measured by a push-rod TMA device, and the measurement temperature range is 30 to 300 ° C.

Next, the silver phosphate-based glass powder was 65% by volume and the refractory filler powder was 35% by volume, and the sealing material B was produced. Here, the average particle diameter D ₅₀ of the silver phosphate-based glass powder is 1.0 μm and the 99% particle size D ₉₉ is 2.5 μm, and the average particle size D ₅₀ of the refractory filler powder is 1.0 μm and 99% particle size D ₉₉ It is 2.5 μm. In addition, silver phosphate-based glass contains 32% Ag ₂ O, 22% P ₂ O ₅ , 27% TeO ₂ , 11% ZnO, and 3% Nb ₂ O in mole%. _5. 5% CuO. In addition, the refractory filler powder is NbZr (PO ₄ ) ₃ .

When the thermal expansion coefficient of the sealing material B obtained was measured, the coefficient of thermal expansion lines 77 × 10 ^{- 7} / ℃. In addition, the thermal expansion coefficient is measured by a push-rod TMA device, and the measurement temperature range is 30 to 150 ° C.

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

When the thermal expansion coefficient of the sealing material C obtained was measured, the coefficient of thermal expansion lines 74 × 10 ^{- 7} / ℃. In addition, the thermal expansion coefficient is measured by a push-rod TMA device, and the measurement temperature range is 30 to 250 ° C.

Next, shown in Table sealing material, having, as shown in FIG. 1 ceramic base frame portion ^- the frame portion (length 30mm × horizontal 30mm × base thickness 0.8mm, the thermal expansion coefficient of 70 × 10 ⁷ / ℃) of A first layer of sealing material is formed on the top of the. In addition, the ceramic-based system 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. At the same time, using the sealing material described in the table, a second sealing material layer was formed along the outer peripheral edge of the glass cover (30 mm in length × 30 mm in width) described in the table. In the table, "alkali borosilicate glass" is BDA manufactured by NEC Glass Co., Ltd., "alkali-free glass" is OA-10G manufactured by NEC Glass Co., Ltd., and "soda lime glass" is commercially available door and window glass. "Glass ceramic" is a sintered laminated sheet containing green sheets of glass powder and refractory filler powder.

In detail, first, the sealing material, the bonding agent, and the solvent described in the table are kneaded so that the viscosity becomes about 120 Pa · s (25 ° C, shear rate: 4), and then three roller mills are used. Kneading is carried out until the powder is uniformly dispersed, and the paste is turned into a paste to obtain a sealing material paste. Next, on the top of the frame portion of the ceramic substrate, the above-mentioned sealing material paste is printed in a frame shape through a screen printer. Similarly, the sealing material paste is printed in a frame shape through a screen printer along the outer peripheral edge of the glass cover. Furthermore, after drying at 120 ° C for 10 minutes in an atmospheric environment, firing at 500 ° C for 10 minutes in an atmospheric environment forms a first sealing material layer and a second sealing material layer with an average thickness of 6.0 μm and an average width of 500 μm .

Finally, after the first sealing material layer formed on the top of the frame portion of the ceramic base is in contact with the second sealing material layer formed on the glass cover, a semiconductor laser with a wavelength of 808 nm and an output of 8 to 32 W is irradiated from the glass cover side , The first sealing material layer and the second sealing material layer are softened and deformed, so that the ceramic substrate and the glass cover are hermetically sealed, and each hermetically sealed package is obtained.

With regard to the gas-tight package obtained, the reliability of cracks and gas-tightness after laser sealing were evaluated. The cracks after laser sealing were evaluated as "○" when no cracks were observed when the sealed portion was observed with an optical microscope, and as "×" when cracks were present.

Next, the airtight package obtained was evaluated for the airtightness reliability under the temperature cycle test. In detail, after performing a temperature cycle test on the obtained gas-tight package, when observing the vicinity of the sealing material layer, the person who did not confirm the deterioration of the airtightness at all, the deterioration, cracking, etc. was evaluated as "○", and it was confirmed Those with deterioration, cracks, peeling, etc. were evaluated as “×”. In addition, the conditions of the temperature cycle test were 125 ° C--55 ° C, 1000 cycles.

Next, the gas-tight package obtained was evaluated for hermetic reliability under the HAST (Highly Accelerated Temperature and Humidity Stress test) test. In detail, after performing HAST on the obtained gas-sealed package, when observing the vicinity of the sealing material layer, the person who did not confirm deterioration, cracks, peeling, etc. for airtight reliability was evaluated as "○", and deterioration was confirmed , Cracks, peeling, etc. are evaluated as “×”. In addition, the test conditions of HAST are 121 ° C., humidity 100%, 2 atm, and 24 hours.

As can be seen from Tables 1 to 3, the evaluation of cracks after the laser sealing of Sample Nos. 1 to 4, 8, 9, 12, and 13 and the evaluation of the airtight reliability are good. On the other hand, Sample Nos. 5 to 7, 10, 11, 14, and 15 are formed on the ceramic substrate without forming the first sealing material layer, so it is necessary to increase the laser output to the value in the table, so that the surface layer of the ceramic substrate and the first The second sealing material layer reacted. As a result, Sample Nos. 5 to 7, 10, 11, 14, and 15 produced cracks after laser sealing, and the airtightness reliability of the airtight package was also low. In addition, regarding samples Nos. 5 to 7, 10, 11, 14, and 15, when the laser output is reduced at the time of laser sealing, the laser sealing strength decreases, and the evaluation of airtight reliability becomes poor. [Industry availability]

The hermetic package system of the present invention is suitable for mounting a hermetically sealed package of internal components such as sensor chips, LEDs, etc., and can also be applied to wavelength conversion of piezoelectric vibration elements and quantum dots dispersed in resin Hermetically sealed body containing components, etc.

1‧‧‧Airtight body

10‧‧‧Ceramic substrate

11‧‧‧Glass cover

12‧‧‧Base

13‧‧‧frame

14‧‧‧Internal components

15‧‧‧Top of the frame

16‧‧‧First sealing material layer

17‧‧‧Second sealing material layer

18‧‧‧Laser irradiation device

L‧‧‧Laser

[Fig. 1] A cross-sectional conceptual diagram for explaining an embodiment of the present invention.

Claims (14)

A method for manufacturing a gas-tight package, with the following procedures: Preparing a ceramic substrate and forming a first sealing material layer on the ceramic substrate; Preparing a glass cover and forming a second sealing material layer on the glass cover; The layer is in contact with the second sealing material layer, and the ceramic substrate and the glass cover are laminated; The layer and the second sealing material layer are hermetically sealed to obtain an airtight package. The method for manufacturing a hermetically sealed package according to item 1, wherein the first sealing material layer contains any one or more of bismuth glass, silver phosphate glass, and tellurium glass, and the second sealing material layer contains bismuth glass, Any one or more of silver phosphate-based glass and tellurium-based glass. The method for manufacturing a gas-tight package as described in item 1 or 2, wherein the average thickness of the first sealing material layer is limited to less than 8.0 μm, the average thickness of the second sealing material layer is limited to less than 8.0 μm, and the first The total thickness of the average thickness of the first sealing material layer and the average thickness of the second sealing material layer is limited to less than 15.0 μm. The method for manufacturing an airtight package according to any one of items 1 to 3, wherein the average width of the first sealing material layer is limited to less than 2000 μm, and the average width of the second sealing material layer is limited to less than 2000 μm. The method for manufacturing a hermetically sealed package according to any one of items 1 to 4, which uses a ceramic substrate having a base portion and a frame portion provided on the base portion, and forms a first sealing material layer on top of the frame portion. The method for manufacturing an airtight package according to any one of items 1 to 5, further comprising a procedure for polishing the surface of the first sealing material layer. The method for manufacturing a gas-tight package according to any one of items 1 to 6, wherein the ceramic substrate is any one of glass ceramics, aluminum nitride, and alumina, or a composite material thereof. The method for manufacturing a hermetically sealed package according to any one of items 1 to 7, wherein the sensor element or the LED element is accommodated in the frame portion of the ceramic base. A gas-tight package with a ceramic base and a glass cover, ceramic base has a base and a frame portion provided on the base, on the top of the frame of the ceramic base, forming bismuth-based glass, silver phosphate-based glass, tellurium-based glass Any one or more of the first sealing material layer is formed on the glass cover to form a second sealing material layer containing any one or more of bismuth-based glass, silver phosphate-based glass and tellurium-based glass, and the first sealing material layer It is airtightly integrated in a state of being arranged in contact with the second sealing material layer. The gas-sealed package according to item 10, wherein the first sealing material layer contains a bismuth glass containing a transition metal oxide in the glass composition, and the second sealing material layer contains bismuth containing a transition metal oxide in the glass composition Department of glass. The gas-sealed package according to item 9 or 10, wherein 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 The total average thickness of the sealing material layer is less than 15.0 μm. The hermetically sealed package according to any one of items 9 to 11, 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 hermetically sealed package according to any one of items 9 to 12, wherein the ceramic substrate is any one of glass ceramic, aluminum nitride, aluminum oxide, or a composite material of these. The hermetically sealed package according to any one of items 9 to 13, wherein the sensor element or the LED element is accommodated in the frame portion of the ceramic base.