JP2018064081A - Airtight package and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To create an airtight package that has high airtight reliability and prevents light reflected on the surface of a glass lid from being projected as a video.SOLUTION: An airtight package of the present invention is an airtight package in which a ceramic substrate and a glass lid are airtightly sealed with a sealant material layer therebetween. The ceramic substrate has a base and a frame part provided on the base; the sealant material layer is arranged between the top of the frame part and the glass lid; the glass lid is arranged on the top of the frame part of the ceramic substrate with the sealant material layer therebetween; all or part of the surface of an area on the top of the frame part of the ceramic substrate in which the glass lid is arranged is inclined with respect to a bottom face of the ceramic substrate at an angle of 1° or more and 45° or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an airtight package and a method for manufacturing the same, and more particularly to an airtight package in which a ceramic substrate and a glass lid are hermetically sealed via a sealing material layer and a method for manufacturing the same.

  In the hermetic package on which the piezoelectric vibration element is mounted, ceramic is used as a base from the viewpoint of thermal conductivity, and glass is used as a lid from the viewpoint of light transmission. A piezoelectric vibration element is a sensitive element that easily deteriorates due to oxygen and moisture in the surrounding environment.

  Conventionally, an organic resin adhesive having low temperature curability has been used as an adhesive material for an airtight package. However, the organic resin adhesive may deteriorate the airtightness of the airtight package over time. Further, when gold-tin solder is used instead of the organic resin adhesive, it is possible to prevent deterioration of the airtightness with time. However, gold-tin solder has a problem that the material cost is high.

  On the other hand, the composite powder containing glass powder and refractory filler powder is characterized by being hardly deteriorated by oxygen and moisture in the surrounding environment and having a low material cost.

  However, since the glass powder has a higher softening temperature than the organic resin adhesive, there is a possibility that the piezoelectric vibration 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 sealed without causing thermal degradation of the piezoelectric vibration element.

JP 2013-239609 A JP 2014-236202 A

  Incidentally, a light reflecting member that is moved by a piezoelectric vibration element is accommodated in an airtight package used for a small projector or the like. The light reflecting member has a function of projecting an image by reflecting light incident from the outside in a predetermined direction.

  However, in the airtight package for this application, a part of the light incident from the outside is reflected on the surface of the glass lid, and the reflected light is projected simultaneously with the light reflected by the light reflecting member, so that the image becomes unclear. The problem arises.

  Therefore, the present invention has been made in view of the above circumstances, and the technical problem thereof is to create an airtight package that is highly airtight and that is difficult to project light reflected on the surface of the glass lid as an image. is there.

  The present inventors have found that the above technical problem can be solved by using a ceramic base having a base and a frame provided on the base, and forming an inclined surface on the frame. As proposed. That is, the hermetic package of the present invention is a hermetic package in which a ceramic base and a glass lid are hermetically sealed via a sealing material layer, and the ceramic base has a base and a frame portion provided on the base. The sealing material layer is disposed between the top of the frame portion of the ceramic substrate and the glass lid, and the glass lid is disposed on the top side of the frame portion of the ceramic substrate via the sealing material layer, The whole or part of the surface of the region where the glass lid is disposed at the top of the frame portion of the ceramic substrate is inclined at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate. To do.

  The hermetic package of the present invention has a ceramic substrate having a base and a frame provided on the base. In this way, it becomes easy to accommodate the piezoelectric vibration element and the like in the hermetic package.

  In the hermetic package of the present invention, the whole or part of the surface of the region where the glass lid is arranged at the top of the frame portion of the ceramic substrate is 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate. Tilt to an angle. As a result, since the light reflected on the surface (upper surface and lower surface) of the glass lid travels in a different direction from the light reflected by the light reflecting member, it becomes difficult to project both lights at the same time, resulting in a clear image. Can be obtained.

  Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective 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. A piezoelectric vibration element 14 is accommodated in the frame portion 13 of the ceramic base 10. And the whole surface of the top part 15 of this frame part 13 inclines about 10 degree seeing from the bottom face of the frame part 13, and the surface roughness Ra is less than 1.0 micrometer. An electrical wiring (not shown) that electrically connects the piezoelectric vibration element 14 and the outside is formed in the ceramic base 10.

  A frame-shaped sealing material layer 16 is formed on the surface of the glass lid 11. The sealing material layer 16 includes bismuth glass and refractory filler powder, but does not substantially include a laser absorber. The width of the sealing material layer 16 is slightly smaller than the width of the top portion 15 of the frame portion 13 of the ceramic base 10. Furthermore, the average thickness of the sealing material layer 16 is less than 8.0 μm.

  The laser beam L emitted from the laser irradiation device 17 is irradiated along the sealing material layer 16 from the glass lid 11 side. As a result, the sealing material layer 16 softens and flows and reacts with the surface layer of the ceramic substrate 10, whereby the aluminum oxide substrate 10 and the glass lid 11 are hermetically integrated, and the hermetic structure of the hermetic package 1 is formed.

  FIG. 2 is a schematic cross-sectional view for explaining the light reflection direction in the hermetic package. As can be seen from FIG. 2A, when the top portion 15x of the frame portion 13x of the ceramic substrate 10x is not inclined, the light Rx1 reflected by the surface of the glass lid 11x is reflected by the light reflecting member (piezoelectric vibration element) 14x. Since the light travels in the same direction as the light Rx2, both the light Rx1 and Rx2 are projected at the same time, and the image becomes unclear. On the other hand, as can be seen from FIG. 2 (b), when the top portion 15 of the frame portion 13 of the ceramic substrate 10 is inclined, the light R 1 reflected by the surface of the glass lid 11 is reflected by the light reflecting member (piezoelectric vibration element) 14. Since the light travels in a different direction from the reflected light R2, the lights R1 and R2 are not projected at the same time, and the image becomes clear.

  Secondly, in the hermetic package of the present invention, the surface roughness Ra of the surface on which the sealing material layer at the top of the frame portion of the ceramic substrate is disposed is preferably less than 1.0 μm. 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.

Thirdly, in the hermetic package of the present invention, the sealing material layer is preferably a sintered body of a composite powder containing at least a bismuth glass powder and a refractory filler powder. Bismuth glass has a feature that a reaction layer can be easily formed on the surface layer of a ceramic substrate at the time of laser sealing as compared with other glass systems. Further, the refractory filler powder can increase the mechanical strength of the sealing material layer while reducing the thermal expansion coefficient of the sealing material layer. The “bismuth-based glass” refers to a glass mainly composed of Bi ₂ O ₃ , and specifically refers to a glass containing 25 mol% or more of Bi ₂ O ₃ in the glass composition.

  Fourth, the hermetic package of the present invention preferably has a total light transmittance of 5% or more and 80% or less at a wavelength of 808 nm in the thickness direction of the sealing material layer. Here, the “total light transmittance” can be measured by a commercially available transmittance measuring device.

  Fifth, in the hermetic package of the present invention, it is preferable that the sealing material layer does not substantially contain a laser absorber. Here, “substantially does not contain a laser absorber” refers to a case where the content of the laser absorber in the sealing material layer is 0.1% by volume or less.

  Sixth, the hermetic package of the present invention preferably has an average thickness of the sealing material layer of less than 8.0 μm. In this way, since the residual stress in the hermetic package is reduced, the hermetic reliability of the hermetic package can be improved.

  Seventhly, in the hermetic package of the present invention, the thermal conductivity of the ceramic substrate is preferably 100 W / (m · K) or more. When the thermal conductivity of the ceramic substrate is high, the ceramic substrate can easily dissipate heat, so that it is possible to prevent the device from excessively generating heat.

  Eighth, in the hermetic package of the present invention, the ceramic base is preferably any one of aluminum nitride, aluminum oxide, and glass ceramic.

  Ninthly, in the hermetic package of the present invention, it is preferable that an antireflection film is formed on one side or both sides of the glass lid.

  10thly, it is preferable that the hermetic package of this invention accommodates the piezoelectric vibration element in the frame part of a ceramic base | substrate.

  Eleventhly, in the hermetic package of the present invention, it is preferable that the ceramic substrate has a property of absorbing the laser beam to be irradiated.

  Twelfth, the hermetic package of the present invention is a hermetic package in which a ceramic base and a glass lid are hermetically sealed via a sealing material layer, and the ceramic base includes a base portion and a frame portion provided on the base. A sealing material layer is disposed between the top of the frame portion of the ceramic substrate and the glass lid, and a glass lid is disposed on the top side of the frame portion of the ceramic substrate via the sealing material layer. And all or part of the outer surface of the glass lid is inclined at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate.

  Thirteenthly, in the hermetic package of the present invention, it is preferable that all or part of the inner surface of the glass lid is inclined at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate.

  14thly, the manufacturing method of the airtight package of this invention WHEREIN: The process of preparing a glass cover, the process of preparing the ceramic base | substrate which has a base part and the frame part provided on the base part, The frame part of a ceramic base | substrate, Inclining all or part of the surface of the area where the glass lid is to be disposed at the top to an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate, and on the top of the frame portion of the ceramic substrate Alternatively, a step of forming a sealing material layer on the glass lid, a step of laminating and arranging the glass lid and the ceramic substrate via the sealing material layer, and laser light from the glass lid side toward the sealing material layer Irradiating and softening and deforming the sealing material layer to hermetically seal the ceramic substrate and the glass lid to obtain an airtight package.

  Fifteenth, in the method for manufacturing an airtight package of the present invention, the whole or part of the surface of the region where the glass lid is to be disposed on the top of the frame portion of the ceramic substrate is physically polished to the bottom surface of the ceramic substrate. It is preferable to incline at an angle of 1 ° or more and 45 ° or less.

It is a perspective schematic diagram for explaining one embodiment of the present invention. It is the cross-sectional schematic for demonstrating the reflection direction of the light in an airtight package. It is a schematic diagram which shows the softening point of the composite powder when measured with a macro type DTA apparatus.

  As described above, the hermetic package of the present invention is a hermetic package in which a ceramic base and a glass lid are hermetically sealed via a sealing material layer. The ceramic base includes a base and a frame provided on the base. A sealing material layer is disposed between the top of the frame portion of the ceramic substrate and the glass lid, and a glass lid is disposed above the top of the frame portion of the ceramic substrate, and the frame portion of the ceramic substrate. The whole or part of the surface of the region where the glass lid is arranged at the top of the substrate is inclined at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate.

  In the hermetic package of the present invention, the ceramic substrate has a base portion and a frame portion provided on the base portion. In this way, it becomes easy to accommodate the piezoelectric vibration element or the like in the frame portion of 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. In addition, the piezoelectric vibration element or the like can be easily accommodated in the frame portion of the ceramic substrate.

  In the hermetic package of the present invention, the surface of the region where the glass lid is arranged at the top of the frame portion of the ceramic substrate is inclined at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate. Is inclined at an angle of 3 ° or more and 30 ° or less, more preferably at an angle of 5 ° or more and 25 ° or less, more preferably at an angle of 7 ° or more and 20 ° or less. Yes. When this inclination angle is small, the light reflected on the surface of the glass lid is easily projected as an image. On the other hand, when the inclination angle is large, the light reflected by the light reflecting member is hardly projected as an image by the wall surface of the frame portion of the ceramic base.

  In the surface of the top of the frame portion of the ceramic substrate, the area ratio of the surface inclined with respect to the bottom surface of the ceramic substrate is preferably 40% or more, 60% or more, 80% or more, 90% or more, and particularly preferably 100. %, That is, the entire top surface of the frame portion is an inclined surface. When the area ratio of the inclined surface is small, it is difficult to fix the glass lid on the top of the frame portion.

  The surface roughness Ra of the surface on which the sealing material layer at the top of the frame portion of the ceramic substrate is disposed is preferably less than 1.0 μm. If the surface roughness Ra of the surface increases, the accuracy of laser sealing tends to decrease.

  The ceramic substrate is preferably any one of aluminum nitride, aluminum oxide, and glass ceramic. Since aluminum nitride and aluminum oxide have good heat dissipation, it is possible to appropriately prevent the heat generation of the airtight package. Moreover, since glass ceramic can form a thermal via easily, the situation which an airtight package heats excessively can be prevented appropriately.

  The thermal conductivity of the ceramic substrate is preferably 100 W / (m · K) or more, 150 W / (m · K) or more, and particularly preferably 200 W / (m · K) or more. If the thermal conductivity of the ceramic substrate is high, the ceramic substrate is likely to dissipate heat, and therefore the temperature of the sealing material layer is difficult to rise at the interface between the ceramic substrate and the sealing material layer during laser sealing.

  The ceramic substrate is preferably dispersed with a black pigment (sintered with the black pigment dispersed). In this way, the ceramic substrate can absorb the laser light transmitted through the sealing material layer. As a result, since the ceramic substrate is heated during laser sealing, the formation of the reaction layer can be promoted at the interface between the sealing material layer and the ceramic substrate.

  The ceramic substrate has the property of absorbing the laser beam to be irradiated, that is, the thickness is 0.5 mm, and the total light transmittance at the wavelength of the laser beam to be irradiated is 10% or less (preferably 5% or less). preferable. Similarly, the ceramic substrate preferably has a total light transmittance of 10% or less (desirably 5% or less) at a thickness of 0.5 mm and a wavelength of 808 nm. If it does in this way, it will become easy to raise the temperature of a sealing material layer in the interface of a ceramic base | substrate and a sealing material layer.

  The ceramic substrate is preferably sintered in a state containing a laser absorber (for example, a black pigment). If it does in this way, the property which absorbs the laser beam which should be irradiated can be provided with respect to a ceramic base | substrate.

  The thickness of the base portion 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 sealing material layer is softened and deformed during laser sealing to form a reaction layer on the surface of the ceramic substrate.

  The average thickness of the sealing material layer is preferably less than 8.0 μm, particularly preferably less than 6.0 μm. The smaller the average thickness of the sealing material layer, the lower the stress remaining in the sealing portion after laser sealing when the thermal expansion coefficients of the sealing material layer 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 the composite powder paste and a method of polishing the surface of the sealing material layer.

  The surface roughness Ra of the sealing material layer is preferably less than 0.5 μm and not more than 0.2 μm, particularly preferably 0.01 to 0.15 μm. Further, the surface roughness RMS of the sealing material layer is preferably less than 1.0 μm and 0.5 μm or less, particularly preferably 0.05 to 0.3 μm. In this way, the adhesion between the ceramic substrate and the sealing material layer is improved, and the accuracy of laser sealing is improved. As described above, examples of the method for regulating the surface roughness Ra and RMS of the sealing material layer include a method of polishing the surface of the sealing material layer and a method of reducing the particle size of the refractory filler powder. The “surface roughness RMS” can be measured by, for example, a stylus type or non-contact type laser film thickness meter or surface roughness meter.

  The line width of the sealing material layer is preferably 350 μm or less, 300 μm or less, 250 μm or less, and particularly preferably 200 μm or less. If the line width of the sealing material layer is too large, the stress remaining in the hermetic package tends to increase.

  The total light transmittance at a wavelength of 808 nm in the thickness direction of the sealing material layer is preferably 5% or more, 10% or more, 15% or more, 20% or more, particularly 25% or more. If the total light transmittance at a wavelength of 808 nm in the thickness direction of the sealing material layer is too low, the region on the glass lid side of the sealing material layer when the laser beam is irradiated from the glass lid side toward the sealing material layer It preferentially softens and flows, and it becomes difficult for the temperature to rise at the interface between the ceramic substrate and the sealing material layer, and it becomes difficult to form a reaction layer on the surface layer of the ceramic substrate. On the other hand, the total light transmittance at a wavelength of 808 nm in the thickness direction of the sealing material layer is preferably 80% or less, 60% or less, 50% or less, 45% or less, particularly 40% or less. If the total light transmittance at a wavelength of 808 nm in the thickness direction of the sealing material layer is too high, the sealing material layer accurately absorbs the laser light even if laser light is irradiated from the glass lid side toward the sealing material layer. Accordingly, the temperature of the sealing material layer is hardly increased, and the reaction layer is hardly formed on the surface layer of the ceramic substrate.

  The sealing material layer is preferably a sintered body of a composite powder containing at least a glass powder and a refractory filler powder. Various materials can be used as the composite powder. Among these, from the viewpoint of increasing the sealing strength, it is preferable to use a composite powder containing a bismuth-based glass powder and a refractory filler powder. In particular, it is preferable to use a composite powder containing 55 to 95% by volume of bismuth glass and 5 to 45% by volume of refractory filler powder as the composite powder, and 60 to 85% by volume of bismuth glass and 15 to 40%. It is more preferable to use a composite powder containing a volume% refractory filler powder, and it is particularly preferable to use a composite powder containing 60 to 80 volume% bismuth glass and 20 to 40 volume% refractory filler powder. . If the refractory filler powder is added, the thermal expansion coefficient of the sealing material layer is easily matched with the thermal expansion coefficient of the glass lid and the ceramic substrate. 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, if the content of the refractory filler powder is too large, the content of the bismuth-based glass powder becomes relatively small, so that the surface smoothness of the sealing material layer is lowered and the accuracy of laser sealing is lowered. It becomes easy.

  The softening point of the composite powder is preferably 500 ° C. or lower, 480 ° C. or lower, particularly 450 ° C. or lower. When the softening point of the composite powder is too high, it is difficult to increase the surface smoothness of the sealing material layer. The lower limit of the softening point of the composite powder is not particularly set, but considering the thermal stability of the glass powder, the softening point of the composite powder is preferably 350 ° C. or higher. Here, the “softening point” is the fourth inflection point when measured with a macro-type DTA apparatus, and corresponds to Ts in FIG.

The bismuth glass preferably contains 28% to 60% Bi ₂ O ₃ , 15 to 37% B ₂ O ₃ , and 1 to 30% ZnO as a glass composition. The reason for limiting the content range of each component as described above will be described below. In the description of the glass composition range,% display indicates mol%.

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%, 19 to 33%, particularly preferably 22 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%, and particularly preferably 7 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.

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

SiO ₂ is a component which enhances the water resistance, the content thereof is 0 to 5%, 0-3%, 0-2%, in particular 0 to 1% is preferred. When the content of SiO ₂ is too large, the softening point is unduly increased. In addition, the glass is easily devitrified during laser sealing.

Al ₂ O ₃ is a component that increases water resistance, and its content is preferably 0 to 10%, 0.1 to 5%, and particularly preferably 0.5 to 3%. 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.

In order to lower the softening point of bismuth 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 devitrified at the time of laser sealing. The 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. Furthermore, if CuO is added, the laser absorption characteristic at the time of laser sealing can be improved. The content of CuO is preferably 0 to 40%, 5 to 35%, 10 to 30%, particularly 13 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. Further, the total light transmittance of the sealing material layer becomes too low.

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 0.4 to 2%. 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, and its content is preferably 0 to 25%, particularly preferably 5 to 15%. When there is too much content of MnO, the component balance of a glass composition will be impaired and devitrification resistance will fall easily.

Sb ₂ O ₃ is a component that increases 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 average particle diameter D50 of the glass powder is preferably less than 15 μm, 0.5 to 10 μm, particularly 1 to ₅ μm. As the average particle diameter D ₅₀ of the glass powder is small, the softening point of the glass powder is 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, β-quartz solid solution, In particular, β-eucryptite or cordierite is preferable. These refractory filler powders have a low thermal expansion coefficient, high mechanical strength, and good compatibility with bismuth glass.

The average particle size D ₅₀ of the refractory filler powder is preferably less than 2 μm, in particular less than 1.5 μm. When the average particle diameter D ₅₀ of the refractory filler powder is less than 2 [mu] m, together with the surface smoothness of the sealing material layer is improved, easily regulate the average thickness of the sealing material layer less than 8.0 .mu.m, as a result The accuracy of laser sealing can be increased.

The 99% particle size D ₉₉ of the refractory filler powder is preferably less than 5 μm, 4 μm or less, in particular 3 μm or less. When the 99% particle size D ₉₉ of the refractory filler powder is less than 5 μm, the surface smoothness of the sealing material layer is improved and the average thickness of the sealing material layer is easily regulated to less than 8.0 μm. As a result, the accuracy of laser sealing can be increased. 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 may further contain a laser absorbing material in order to enhance the light absorption characteristics. However, the laser absorbing material excessively increases the light absorbing characteristics of the sealing material layer and reduces devitrification of the bismuth-based glass. It has a promoting effect. Therefore, the content of the laser absorbing material in the sealing material layer 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 substantially not contained. 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 is preferably 60 × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C., 65 × 10 ^{−7 to} 82 × 10 ⁻⁷ / ° C., particularly 68 × 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 glass lid or the ceramic base, and the stress remaining in the sealing portion is reduced. The “thermal expansion coefficient” is a value measured with a TMA (push bar thermal expansion coefficient measurement) device in a temperature range of 30 to 300 ° C.

  The sealing material layer can be formed by various methods. Among them, it is preferable to form the sealing material layer by applying and sintering a composite powder paste. The composite powder paste is preferably applied by using a coating machine such as a dispenser or a screen printing machine. In this way, the dimensional accuracy of the sealing material layer can be increased. Here, the composite powder paste is a mixture of composite powder and 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 composite powder paste may be applied on the top of the frame portion of the ceramic substrate, but is preferably applied in a frame shape along the outer peripheral edge region of the glass lid. In this way, it is possible to project light reflected from the piezoelectric vibration element or the like over a wide range while suppressing thermal deterioration of the piezoelectric vibration element.

  The composite powder paste is usually produced by kneading the composite powder and 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 the vehicle 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 glasses can be used as the glass lid. For example, alkali-free glass, borosilicate glass, and soda lime glass can be used. In particular, in order to increase the total light transmittance in the ultraviolet wavelength region, a low iron-containing glass lid (the content of Fe ₂ O ₃ in the glass composition is 0.015% by mass or less, particularly less than 0.010% by mass) is used. It is preferable.

  Various functional films may be formed on one side or both sides of the glass lid. In particular, an antireflection film is preferably formed on one side or both sides of the glass lid. Thereby, the light reflected on the surface of the glass lid is reduced, and a clear image is easily obtained.

  The plate 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. Further, the total light transmittance in the ultraviolet wavelength region can be increased.

The difference in thermal expansion coefficient between the sealing material layer and the glass lid is preferably less than 40 × 10 ⁻⁷ / ° C., particularly preferably 25 × 10 ⁻⁷ / ° C. or less. If these thermal expansion coefficient differences are too large, the stress remaining in the sealed portion becomes unduly high, and the hermetic reliability of the hermetic package tends to be lowered.

  The hermetic package of the present invention is a hermetic package in which a ceramic base and a glass lid are hermetically sealed via a sealing material layer. The ceramic base has a base and a frame provided on the base. A sealing material layer is disposed between the top of the frame portion of the substrate and the glass lid, and a glass lid is disposed on the top of the frame portion of the ceramic substrate via the sealing material layer. All or part of the outer surface of the ceramic substrate is inclined at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate. In the hermetic package of the present invention, as described above, the outer surface of the glass lid is inclined with respect to the bottom surface of the ceramic substrate by forming an inclined surface in the frame portion of the ceramic substrate. As a method of inclining the outer surface of the lid, for example, the outer surface of the glass lid is made to be the bottom surface of the ceramic base by polishing or heat-processing the glass lid without forming an inclined surface in the frame portion of the ceramic base. You may make it incline with respect to. Further, the outer surface of the glass lid may be inclined with respect to the bottom surface of the ceramic substrate by adjusting the thickness of the sealing material layer without forming the inclined surface on the frame portion of the ceramic substrate. In the former method, the production efficiency of the ceramic substrate can be increased. In the case of the latter method, a separate process is not required for the glass lid, and the outer surface and the inner surface of the glass lid have substantially the same inclination angle.

  The manufacturing method of the hermetic package of the present invention includes a step of preparing a glass lid, a step of preparing a ceramic base having a base and a frame provided on the base, and a glass lid at the top of the frame of the ceramic base. Inclining all or part of the surface of the region to be disposed with respect to the bottom surface of the ceramic substrate at an angle of 1 ° or more and 45 ° or less, and on the top of the frame portion of the ceramic substrate or on the glass lid A step of forming a sealing material layer, a step of laminating and arranging a glass lid and a ceramic substrate via the sealing material layer, and applying a laser beam from the glass lid side toward the sealing material layer for sealing And a step of airtightly sealing the ceramic substrate and the glass lid by softening and deforming the material layer to obtain an airtight package. The technical characteristics of the manufacturing method of the hermetic package of the present invention overlap with the technical characteristics of the hermetic package of the present invention. In the present specification, detailed description of the overlapping portions is omitted for convenience.

  In the manufacturing method of the hermetic package of the present invention, by physical polishing, all or part of the surface of the region where the glass lid is to be disposed at the top of the frame portion of the ceramic substrate is 1 ° or more with respect to the bottom surface of the ceramic substrate, And it is preferable to incline at an angle of 45 ° or less. In this way, the dimensional accuracy of the inclined surface can be increased. In addition, the well-known polishing powder and polishing apparatus can be used suitably for the polishing powder and polishing apparatus used for physical polishing.

  The manufacturing method of the hermetic package of the present invention is to hermetically seal the ceramic substrate and the glass lid by irradiating laser light from the glass lid side toward the sealing material layer and softening and deforming the sealing material layer. And obtaining a hermetic package. 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.

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, preheating the glass lid at a temperature (100 ° C. or higher and below the heat resistance temperature of the piezoelectric vibration element or the like in the ceramic substrate) can suppress breakage of the glass lid due to thermal shock. . 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.

  Laser sealing is preferably performed with the glass lid pressed. Thereby, the softening deformation of the sealing material layer can be promoted at the time of laser sealing.

  Hereinafter, based on an Example, this invention is demonstrated in detail. The following examples are merely illustrative. The present invention is not limited to the following examples.

First, bismuth-based glass powder and refractory filler powder were mixed at a ratio shown in Table 1 to produce composite powders shown in Table 1. The average particle diameter _{D 50} of the bismuth-based glass powder 1.0 .mu.m, 99% particle size _{D 99} was 2.5 [mu] m. The average particle diameter _{D 50} of the refractory filler powder is 1.0 .mu.m, 99% particle size _{D 99} was 2.5 [mu] m.

  About the obtained composite powder, the thermal expansion coefficient was measured. The results are shown in Table 1. In addition, a thermal expansion coefficient is the value measured with the push rod type | mold TMA apparatus, and a measurement temperature range is 30-300 degreeC.

Next, using the composite powder, a frame shape is formed on the outer peripheral edge of a glass lid (length 10 mm × width 10 mm × thickness 0.2 mm, alkali borosilicate glass substrate, coefficient of thermal expansion 66 × 10 ⁻⁷ / ° C.). A sealing material layer was formed. In detail, first, after kneading the composite powder, vehicle, and solvent shown in Table 1 so that the viscosity is about 100 Pa · s (25 ° C., Shear rate: 4), the powder is evenly mixed with a three-roll mill. The mixture was kneaded until dispersed to obtain a composite powder paste. A vehicle in which an ethyl cellulose resin was dissolved in a glycol ether solvent was used. Next, the composite powder 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, baking is performed at 500 ° C. for 10 minutes in an air atmosphere to form a sealing material layer having a thickness of 5.0 μm and a width of 200 μm on the glass lid. did.

In addition, an aluminum oxide substrate (length 10 mm × width 10 mm × base thickness 0.7 mm, thermal expansion coefficient 70 × 10 ⁻⁷ / ° C.) was prepared. The frame portion has a frame shape with a width of 600 μm and a height of 400 μm, and is formed along the outer peripheral edge of the base portion of the aluminum oxide base.

  Next, the entire surface of the top portion of the frame portion of the aluminum oxide substrate was polished, and the entire surface of the top portion of the frame portion of the aluminum oxide substrate was inclined with respect to the bottom surface of the ceramic substrate at an angle shown in the table. The inclined surface had a surface roughness Ra of 0.5 μm.

Subsequently, the piezoelectric vibration element was accommodated in the frame portion of the aluminum oxide substrate. Finally, after laminating and arranging the aluminum oxide substrate and the glass lid so that the top of the frame portion of the aluminum oxide substrate and the sealing material layer are in contact with each other, the wavelength of 808 nm and 7 W from the glass lid side toward the sealing material layer By irradiating the semiconductor laser to soften and deform the sealing material layer, the aluminum oxide substrate and the glass lid were hermetically sealed to obtain respective hermetic packages (Sample Nos. 1 to 4).

  The sealing strength was evaluated about the obtained airtight package. Specifically, after separating the aluminum oxide substrate from the obtained airtight package, the sealing material layer disposed on the top of the frame portion of the aluminum oxide substrate was removed, and the surface layer on the top of the frame portion was visually observed, The sealing strength was evaluated with “◯” indicating that the reaction mark was observed and “X” indicating that no reaction mark was observed.

  The airtight reliability of the obtained airtight package was evaluated. More specifically, after the high-temperature, high-humidity and high-pressure test: HAST test (Highly Accelerated Temperature and Humidity Stress test) was performed on the obtained hermetic package, the vicinity of the sealing material layer was observed. The airtight reliability was evaluated with “◯” indicating that no peeling or the like was observed, and “X” indicating that alteration, cracking, peeling or the like was observed. The conditions of the HAST test are 121 ° C., humidity 100%, 2 atm, and 24 hours.

  The obtained airtight package was projected as an image when the light reflected from the glass lid was not projected as an image when light was incident on the piezoelectric vibration element at an angle of 45 ° from the outside. Things were evaluated as “x”.

  As is clear from Table 1, sample No. Nos. 1 to 3 have good evaluation of sealing strength and airtight reliability, and furthermore, the top of the frame portion of the aluminum oxide substrate is appropriately tilted, so that the light reflected on the surface of the glass lid is not projected as an image. It was. On the other hand, sample No. In No. 4, since the top part of the frame part of the aluminum oxide base was not inclined, the light reflected by the surface of the glass lid was projected as an image.

  The hermetic package of the present invention is suitable for an airtight package on which a piezoelectric vibration element is mounted, but can also be suitably applied to an airtight package that contains a resin or the like in which quantum dots are dispersed.

DESCRIPTION OF SYMBOLS 1 Airtight package 10 Ceramic base | substrate 11 Glass cover 12 Base part 13 Frame part 14 Light reflection member (piezoelectric vibration element)
15 Top 16 of frame part 16 Sealing material layer 17 Laser irradiation apparatus L Laser beam

Claims (15)

In an airtight package in which a ceramic substrate and a glass lid are hermetically sealed via a sealing material layer,
The ceramic base has a base and a frame provided on the base,
A sealing material layer is disposed between the top of the frame of the ceramic substrate and the glass lid;
And the glass lid is arranged on the top side of the frame portion of the ceramic substrate via the sealing material layer, and all or part of the surface of the region where the glass lid is arranged on the top portion of the frame portion of the ceramic substrate, An airtight package characterized by being inclined at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate.   2. The airtight package according to claim 1, wherein the surface roughness Ra of the surface on which the sealing material layer is arranged at the top of the frame portion of the ceramic substrate is less than 1.0 [mu] m.   The hermetic package according to claim 1 or 2, wherein the sealing material layer is a composite powder sintered body containing at least a bismuth-based glass powder and a refractory filler powder.   The hermetic package according to any one of claims 1 to 3, wherein the total light transmittance at a wavelength of 808 nm in the thickness direction of the sealing material layer is 5% or more and 80% or less.   The hermetic package according to any one of claims 1 to 4, wherein the sealing material layer does not substantially contain a laser absorber.   6. The hermetic package according to claim 1, wherein an average thickness of the sealing material layer is less than 8.0 μm.   The hermetic package according to any one of claims 1 to 6, wherein the ceramic substrate has a thermal conductivity of 100 W / (m · K) or more.   The hermetic package according to any one of claims 1 to 7, wherein the ceramic substrate is any one of aluminum nitride, aluminum oxide, and glass ceramic.   The airtight package according to any one of claims 1 to 8, wherein an antireflection film is formed on one side or both sides of the glass lid.   The hermetic package according to any one of claims 1 to 9, wherein a piezoelectric vibration element is accommodated in a frame portion of the ceramic substrate.   The hermetic package according to any one of claims 1 to 10, wherein the ceramic substrate has a property of absorbing laser light to be irradiated. In an airtight package in which a ceramic substrate and a glass lid are hermetically sealed via a sealing material layer,
The ceramic base has a base and a frame provided on the base,
A sealing material layer is disposed between the top of the frame of the ceramic substrate and the glass lid;
In addition, a glass lid is disposed on the top side of the frame portion of the ceramic substrate via a sealing material layer, and all or part of the outer surface of the glass lid is 1 ° or more with respect to the bottom surface of the ceramic substrate, And an airtight package which is inclined at an angle of 45 ° or less.   The whole or part of the inner surface of the glass lid is inclined at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate. Airtight package. Preparing a glass lid;
Providing a ceramic substrate having a base and a frame provided on the base;
Inclining the whole or part of the surface of the region where the glass lid is to be disposed at the top of the frame portion of the ceramic substrate at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate;
Forming a sealing material layer on the top of the frame of the ceramic substrate or on the glass lid;
A step of laminating and arranging a glass lid and a ceramic substrate via a sealing material layer;
Irradiating a laser beam from the glass lid side toward the sealing material layer to soften and deform the sealing material layer, thereby hermetically sealing the ceramic base and the glass lid to obtain an airtight package. An airtight package manufacturing method characterized by the above.   By physical polishing, all or part of the surface of the region where the glass lid is to be disposed at the top of the frame portion of the ceramic substrate is inclined at an angle of 1 ° or more and 45 ° or less with respect to the bottom surface of the ceramic substrate. The method of manufacturing an airtight package according to claim 14.