JP2021061354A - Protective cap, light-emitting device, and manufacturing method of protective cap - Google Patents

Abstract

To reduce the absorption of light in a protective cap and increases the efficiency of light extraction through a protective cap.SOLUTION: A glass protective cap 2 includes a tubular side wall portion 5 having a joint opening end 5c at the base end, a lid 6 provided on the tip side of the side wall portion 5, and a corner 7 connecting the side wall 5 and a lid 6, and includes a first concave portion 10 in which the inner surface 7a of the corner 7 is recessed toward the outer surface 7b of the corner 7, and a second concave surface portion 11 in which the outer surface 7b of the corner 7 is recessed toward the inner surface 7a of the corner 7.SELECTED DRAWING: Figure 1

Description

The present invention relates to a protective cap made of glass, a method for manufacturing the same, and a light emitting device provided with the protective cap made of glass.

Light emitting devices using LED elements have come to be used in various fields such as lighting and communication because of their long life and energy saving.

In this type of light emitting device, in order to protect the LED element, a package in which the LED element is arranged inside a container-shaped ceramic base material and sealed with a plate-shaped transparent lid is adopted.

In recent years, in the above-mentioned packages, a configuration in which the lid has a cap shape has been developed. In a package having such a configuration, a protective cap is bonded onto a base material on which the LED element is mounted, and the LED element is housed in a space surrounded by the base material and the protective cap.

Some protective caps are made of quartz, but they are very expensive. Therefore, for example, Patent Document 1 discloses that a protective cap (sealing cap) made of glass is used.

Japanese Unexamined Patent Publication No. 2003-187768

The protective cap disclosed in Patent Document 1 includes a tubular side wall portion, a lid portion provided on the tip end side of the side wall portion, and a corner portion connecting the side wall portion and the lid portion. The inner surface and the outer surface each have a right-angled portion that bends at a right angle. Therefore, the thickness of the corner portion is inevitably larger than the thickness of the lid portion.

Here, no matter how the material of the glass constituting the protective cap is adjusted, the absorption of light inevitably increases as the thickness of the glass increases. That is, the protective cap disclosed in Patent Document 1 has a problem that the absorption of light at the corners is increased and the efficiency of light extraction through the protective cap is deteriorated. Especially in a short wavelength region such as an ultraviolet region, a problem of light absorption at a corner is likely to occur.

An object of the present invention is to reduce the absorption of light in the protective cap and to increase the efficiency of light extraction through the protective cap.

The present invention, which was devised to solve the above problems, connects a tubular side wall portion having a joint opening end at the base end, a lid portion provided on the tip end side of the side wall portion, and the side wall portion and the lid portion. A protective cap made of glass with a corner portion, wherein the inner surface of the corner portion has a first concave surface portion recessed toward the outer surface of the corner portion, and the outer surface of the corner portion is a corner portion. It is characterized by having a second concave surface portion recessed toward the inner surface of the lid.

By doing so, the first concave surface portion is formed on the inner surface of the corner portion and the second concave surface portion is formed on the outer surface of the corner portion, so that the inner surface and the outer surface of the corner portion come close to each other. The thickness of the corners becomes smaller. As a result, the absorption of light at the corners can be reduced, and the efficiency of light extraction through the protective cap can be improved.

In the above configuration, it is preferable that the inner peripheral edge of the second concave surface portion is located within the range defined by the inner peripheral edge of the joint opening end when viewed from the tubular axis direction of the side wall portion.

By doing so, the thickness of the corner portion can be efficiently reduced, so that the absorption of light at the corner portion can be reduced more reliably.

In the above configuration, the outer peripheral edge of the second concave surface portion is located within the range from the inner surface of the lid portion to the joint opening end when viewed from the direction orthogonal to the tubular axis direction of the side wall portion. Is preferable.

By doing so, the thickness of the corner portion can be efficiently reduced, so that the absorption of light at the corner portion can be reduced more reliably.

In the above configuration, it is preferable that each of the first concave surface portion and the second concave surface portion is composed of an etching surface.

In this way, each of the first concave surface portion and the second concave surface portion is composed of a smooth surface having extremely few defects (for example, microcracks) that can cause damage, so that the strength of the protective cap can be increased. it can.

In the above configuration, it is preferable that the arithmetic average roughness Ra of each of the first concave surface portion and the second concave surface portion is 100 nm or less. Here, the arithmetic mean roughness Ra is a value measured in accordance with JIS B 0601: 2013 (hereinafter, the same applies).

In this way, since each of the first concave surface portion and the second concave surface portion is composed of a smooth surface from which minute defects (for example, microcracks) have been removed, the strength of the protective cap can be increased.

In the above configuration, it is preferable that the outer surface of the lid portion forming the top of the protective cap is a polished surface or a fire-made surface, and the arithmetic average roughness Ra of the outer surface of the lid portion is 100 nm or less. Here, the fire-made surface means an unpolished surface that is solidified without contacting other members such as rollers after the glass is melted (hereinafter, the same applies).

By doing so, since the outer surface of the lid portion is composed of a smooth surface from which minute defects (for example, microcracks) have been removed, the strength of the protective cap can be increased.

In the above configuration, the glass is preferably an ultraviolet transmissive glass having a thickness of 0.7 mm and an internal transmittance of 10% or more at a wavelength of 200 nm.

By doing so, it is possible to efficiently suppress the absorption of light in the protective cap in a short wavelength region such as an ultraviolet region.

In the above configuration, a metallized layer may be formed at the joint opening end. Alternatively, a solder layer may be formed at the end of the joint opening via a metallized layer.

In this way, the metallized layer improves the adhesion between the glass protective cap and the solder layer. Therefore, the solder layer can be used to reliably bond the joint opening end of the protective cap to the base material.

The present invention, which was devised to solve the above problems, is a light emitting device, which comprises a protective cap having the above configuration as appropriate, a base material to which the joint opening end of the protective cap is bonded, a protective cap, and a base. It is characterized by having a light emitting element housed in a space surrounded by a material.

In this way, it is possible to reduce the absorption of light in the protective cap and increase the efficiency of light extraction through the protective cap.

In the above configuration, the light emitting element may be an ultraviolet LED element.

In this way, light in the ultraviolet region, where light absorption is particularly problematic, is emitted from the light emitting element. Therefore, the effect of the light emitting device according to the present invention that the absorption of light in the protective cap can be reduced becomes more useful. In this case, the light emitting device can be used as a sterilizer for sterilizing a predetermined object by the effect of ultraviolet rays, for example.

The present invention, which was devised to solve the above problems, connects a tubular side wall portion having a joint opening end at a base end, a lid portion provided on the tip end side of the side wall portion, and a side wall portion and a lid portion. This is a method for manufacturing a protective cap made of glass having a corner portion to be formed, in which a first concave surface portion is formed by etching on the inner surface of the corner portion and a second concave surface portion is formed by etching on the outer surface of the corner portion. It is characterized by including an etching process for performing.

In this way, the first concave surface is formed on the inner surface of the corner of the protective cap, and the second concave surface is formed on the outer surface of the corner of the protective cap. The outer surfaces come close to each other, and the thickness of the corners becomes smaller. As a result, the absorption of light at the corners of the protective cap can be reduced, and the efficiency of light extraction through the protective cap can be improved. Further, since each of the first concave surface portion and the second concave surface portion is composed of a smooth etching surface having extremely few defects (for example, microcracks) that can cause damage, the protective cap of the protective cap as the thickness of the corner portion decreases. It is also possible to suppress a decrease in strength.

The present invention, which was devised to solve the above problems, connects a tubular side wall portion having a joint opening end at a base end, a lid portion provided on the tip end side of the side wall portion, and the side wall portion and the lid portion. A method for manufacturing a protective cap made of glass having corners to be formed, which comprises a preparatory step of preparing a plate-shaped glass base material having a pair of first and second main surfaces and a glass base material. The first etching step of forming the first recesses constituting the inner surfaces of the side wall portion, the lid portion and the corner portion of the protective cap on the first main surface by etching, and the first on the second main surface of the glass base material. A second etching step of forming a second recess forming the outer surface of the corner of the protective cap by etching at a position corresponding to the periphery of the recess, and a cutting step of cutting the glass base material at a position corresponding to the second recess. It is characterized by having and.

In this way, the first concave surface is formed on the inner surface of the corner of the protective cap, and the second concave surface is formed on the outer surface of the corner of the protective cap. The outer surfaces come close to each other, and the thickness of the corners becomes smaller. As a result, the absorption of light at the corners of the protective cap can be reduced, and the efficiency of light extraction through the protective cap can be improved. Further, since each of the inner surface of the protective cap including the first concave surface portion and the second concave surface portion is composed of a smooth etching surface having extremely few defects (for example, microcracks) that can cause damage, the thickness of the corner portion is formed. It is also possible to suppress a decrease in the strength of the protective cap due to the decrease in etching.

In the above configuration, the first and second main surfaces of the glass base material are composed of a polished surface or a fire-made surface, and the first main surface of the glass base material is before etching in the first etching step. The first protective mask is formed in advance so that the portion other than the region where the first recess is formed is not etched, and the second of the second main surfaces of the glass base material is before etching in the second etching step. It is preferable to pre-form a second protective mask so that the portion other than the recessed region is not etched.

In this way, a polished surface or a fire-made surface remains in the protective cap at the portion where the protective mask is formed. Therefore, most of the inner and outer surfaces of the protective cap can be composed of a polished or fired surface and an etched surface.

In the above configuration, it is preferable to form a metallized layer on the first main surface as the first protective mask.

By doing so, since the protective mask can be used as it is as the metallized layer after the etching step is completed, it is not necessary to peel off the protective mask on the first main surface.

In the above configuration, it is preferable to dig the first recess and the second recess only by etching.

In this way, each of the first recess and the second recess becomes a very smooth surface.

In this case, the glass base material is preferably formed into a plate shape by the overflow down draw method.

In this way, the first main surface and the second main surface of the glass base material become very smooth fire-made surfaces, and the strength of the protective cap is improved.

According to the present invention, it is possible to reduce the absorption of light in the protective cap and increase the efficiency of light extraction through the protective cap.

It is sectional drawing of the light emitting device which concerns on 1st Embodiment. It is sectional drawing of the protective cap included in FIG. It is a top view of the protective cap included in FIG. (A) to (f) are cross-sectional views showing each step included in the manufacturing method of the light emitting device according to the first embodiment. It is a flow chart which shows the manufacturing method of the light emitting device which concerns on 2nd Embodiment. It is a flow chart which shows the manufacturing method of the light emitting device which concerns on 3rd Embodiment. It is a flow chart which shows the manufacturing method of the light emitting device which concerns on 4th Embodiment. It is sectional drawing of the light emitting device which concerns on 5th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First Embodiment)
As shown in FIG. 1, the light emitting device 1 according to the first embodiment is in a space S surrounded by a protective cap 2, a base material 3 to which the protective cap 2 is bonded, and the protective cap 2 and the base material 3. It includes a housed light emitting element 4.

The protective cap 2 includes a tubular side wall portion 5, a lid portion 6 provided on the tip end side (upper end side in the drawing) of the side wall portion 5, and a corner portion 7 connecting the side wall portion 5 and the lid portion 6. ing. The protective cap 2 is a single glass component in which the side wall portion 5, the lid portion 6, and the corner portion 7 are integrally formed.

The base end (lower end in the drawing) of the side wall portion 5 is a joint opening end 5c for joining the protective cap 2 to the base material 3. In the present embodiment, the metallized layer 8 and the solder layer 9 are formed on the joint opening end 5c in this order from the joint opening end 5c side. The metallized layer 8 is a metal film formed on the glass surface of the joint opening end 5c by vapor deposition, sputtering, or the like, and has a role of improving the adhesion with the solder layer 9. As the material of the metallized layer 8, for example, Cr, Ti, Ni, Pt, Au, Co and an alloy layer containing these, or a multilayer film of these metals and alloys can be used. As the material of the solder layer 9, for example, Au, Sn, Ag, Pb, and alloys containing these metals, that is, Au-Sn-based solder, Sn-Ag-based solder, Pb-based solder, and the like can be used.

The protective cap 2 and the base material 3 are joined by a metallized layer 8 and a solder layer 9, but the joining method is not limited to this. For example, the protective cap 2 and the base material 3 may be bonded by a resin adhesive layer if deterioration due to light emitted from the light emitting element 4 is not a problem.

Each of the inner surface 6a and the outer surface 6b of the lid portion 6 has a flat surface portion extending along a direction orthogonal to the tubular axis direction A of the side wall portion 5.

The inner surface 7a of the corner portion 7 has a first concave surface portion 10 recessed toward the outer surface 7b of the corner portion 7. The outer surface 7b of the corner portion 7 has a second concave surface portion 11 recessed toward the inner surface 7a of the corner portion 7. That is, the inner surface 7a and the outer surface 7b of the corner portion 7 are brought close to each other by the first concave surface portion 10 and the second concave surface portion 11, and the thickness of the corner portion 7 is reduced. Therefore, the light emitted from the light emitting element 4 is less likely to be absorbed by the corner portion 7, and the light extraction efficiency through the protective cap 2 can be improved.

In the present embodiment, the first concave surface portion 10 is composed of only a curved surface portion, but the first concave surface portion 10 may have a curved surface portion and a flat surface portion. Further, in the present embodiment, the second concave surface portion 11 is composed of a curved surface portion and a flat surface portion, but the second concave surface portion 11 may be composed of only a curved surface portion. Further, in the present embodiment, the inner surface 5a of the side wall portion 5 is composed of a curved surface portion smoothly continuous with the first concave surface portion 10, but the inner surface 5a of the side wall portion 5 is the same as the outer surface 5b thereof. In addition, it may be composed of a flat surface portion extending along the tubular axis direction A of the side wall portion 5.

As shown in FIGS. 2 and 3, the inner peripheral edge P of the second concave surface portion 11 is the case where the protective cap 2 is viewed in a plan view (FIG. 3), that is, the tubular axial direction A of the side wall portion 5 (directly above or directly above in FIG. 2). When viewed from directly below), it must be located within the range X (including the position corresponding to the inner peripheral edge Q of the joint opening end 5c) partitioned by the inner peripheral edge Q of the joint opening end 5c of the side wall portion 5. preferable. By doing so, the thickness of the corner portion 7 can be efficiently reduced. Of course, the inner peripheral edge P of the second concave surface portion 11 may be located outside the range X when viewed from the tubular axis direction A of the side wall portion 5.

Further, the outer peripheral edge R of the second concave surface portion 11 is the lid portion 6 when the protective cap 2 is viewed from the side, that is, when viewed from a direction orthogonal to the tubular axis direction A of the side wall portion 5 (right beside in the drawing). It is preferably located within the range Y from the inner surface 6a to the joint opening end 5c (including the position corresponding to the inner surface 6a of the lid portion 6). In other words, the outer peripheral edge R of the second concave surface portion 11 is preferably located lower than the height of the inner surface 6a of the lid portion 6. By doing so, the thickness of the corner portion 7 can be efficiently reduced. Of course, the outer peripheral edge R of the second concave surface portion 11 may be located outside the range Y when viewed from a direction orthogonal to the tubular axis direction A of the side wall portion 5.

In the present embodiment, each of the first concave surface portion 10 and the second concave surface portion 11 is composed of an etched surface. Further, the inner surface 6a of the lid portion 6 is composed of an etched surface, and the outer surface 6b of the lid portion 6 is composed of a non-etched surface such as a polished surface or a fire-made surface. When the outer surface 6b of the lid portion 6 is composed of a fire-made surface, the first concave surface portion 10, the second concave surface portion 11, the inner surface 6a of the lid portion 6 and the outer surface 6b of the lid portion 6 are the causes of damage. The surface becomes a smooth surface with extremely few possible defects (for example, microcracks). Further, when the outer surface 6b of the lid portion 6 is composed of a polished surface, it is preferable that the outer surface 6b is composed of a mirror-polished surface. In the present embodiment, the inner surface 5a of the side wall portion 5 is also composed of an etched surface.

The arithmetic mean roughness Ra of the outer surface 6b of the lid portion 6 is, for example, preferably 100 nm or less, more preferably 50 nm or less, and most preferably 5 nm or less. On the other hand, the arithmetic average roughness Ra of the etched surface, that is, the inner surface 6a of the first concave surface portion 10, the second concave surface portion 11 and the lid portion 6 is, for example, preferably 100 nm or less, and preferably 60 nm or less. It is more preferably 30 nm or less, and further preferably 10 nm or less.

The base material 3 is a plate-shaped member on which the light emitting element 4 is mounted. The base material 3 is composed of, for example, ceramics such as aluminum nitride and aluminum oxide, silicon compounds such as glass, glass ceramics and silicon, or a composite material of these with metals such as Ag and Cu.

The light emitting element 4 is not particularly limited, but is an ultraviolet LED element in the present embodiment. The ultraviolet LED element is a light source device that emits light rays in the ultraviolet wavelength band. In this case, the protective cap 2 is preferably made of ultraviolet transmissive glass. The ultraviolet transmissive glass preferably has an internal transmittance of 10% or more at a thickness of 0.7 mm and a wavelength of 200 nm.

The glass composition of the ultraviolet transmissive glass that can realize such characteristics is SiO ₂ 50 to 80%, Al ₂ O ₃ + B ₂ O _{3 1 to} 45%, Li ₂ O + Na ₂ O + K ₂ O 0 to 0 by mass. It is preferably 25% and MgO + CaO + SrO + BaO 0 to 25%. The reasons for limiting the content of each component as described above are shown below. In the description of the content of each component, the% indication indicates mass% unless otherwise specified.

SiO ₂ is a main component forming the skeleton of glass. The content of SiO ₂ is preferably 50 to 80%, 55 to 75%, 58 to 70%, and particularly 60 to 68%. If _{the content of SiO 2} is too small, Young's modulus and acid resistance tend to decrease. On the other hand, if _{the content of SiO 2} is too large, the high-temperature viscosity becomes high and the meltability tends to decrease, and devitrified crystals such as cristobalite tend to precipitate, so that the liquidus temperature tends to rise. Become.

Al ₂ O ₃ and B ₂ O ₃ are components that enhance devitrification resistance. The content of Al ₂ O ₃ + B ₂ O ₃ is preferably 1 to 40%, 5 to 35%, 10 to 30%, and particularly 15 to 25%. If _{the content of Al 2} O ₃ + B ₂ O ₃ is too small, the glass tends to be devitrified. On the other hand, if _{the content of Al 2} O ₃ + B ₂ O ₃ is too large, the component balance of the glass composition is impaired, and conversely, the glass tends to be devitrified.

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

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

Li ₂ O, Na ₂ O and K ₂ O are components that lower the high-temperature viscosity, significantly increase the meltability, and contribute to the initial melting of the glass raw material. The content of Li ₂ O + Na ₂ O + K ₂ O is preferably 0 to 25%, 1 to 20%, 4 to 15%, and particularly 7 to 13%. If _{the content of Li 2} O + Na ₂ O + K ₂ O is too small, the meltability tends to decrease. On the other hand, if _{the content of Na 2} O is too large, the coefficient of thermal expansion may become unreasonably high.

Li ₂ O is a component that lowers the high-temperature viscosity, significantly enhances the meltability, and contributes to the initial melting of the glass raw material. The content of Li ₂ O is preferably 0 to 5%, 0 to 3%, 0 to 1%, and particularly 0 to 0.1%. If _{the content of Li 2} O is too small, the meltability tends to decrease and the coefficient of thermal expansion may become unreasonably low. On the other hand, if _{the content of Li 2} O is too large, the glass tends to be phase-separated.

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

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

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

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

CaO is a component that lowers high-temperature viscosity and significantly increases meltability. Further, among alkaline earth metal oxides, since the introduced raw material is relatively inexpensive, it is a component that reduces the raw material cost. The CaO content is preferably 0 to 15%, 0.5 to 10%, and particularly 1 to 5%. If the CaO content is too high, the glass tends to be devitrified. If the CaO content is too small, it becomes difficult to enjoy the above effects.

SrO is a component that enhances devitrification resistance. The content of SrO is preferably 0 to 7%, 0 to 5%, 0 to 3%, particularly less than 0 to 1%. If the content of SrO is too high, the glass tends to be devitrified.

BaO is a component that enhances devitrification resistance. The content of BaO is preferably 0 to 7%, 0 to 5%, 0 to 3%, and less than 0 to 1%. If the BaO content is too high, the glass tends to be devitrified.

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

ZnO is a component that enhances meltability, but if it is contained in a large amount in the glass composition, the glass tends to be devitrified. Therefore, the ZnO content is preferably 0 to 5%, 0 to 3%, 0 to 1%, less than 0 to 1%, and particularly 0 to 0.1%.

ZrO ₂ is a component that enhances acid resistance, but if it is contained in a large amount in the glass composition, the glass tends to be devitrified. Therefore, _{the content of ZrO 2} is preferably 0 to 5%, 0 to 3%, 0 to 1%, 0 to 0.5%, and particularly 0.001 to 0.2%.

Fe ₂ O ₃ and TiO ₂ are components that reduce the transmittance in the deep ultraviolet region. The content of Fe ₂ O ₃ + TiO ₂ is preferably 100 ppm or less, 80 ppm or less, 60 ppm or less, 0.1 to 40 ppm or less, and particularly 1 to 20 ppm. If _{the content of Fe 2} O ₃ + TiO ₂ is too large, the glass is colored and the transmittance in the deep ultraviolet region tends to decrease. If _{the content of Fe 2} O ₃ + TiO ₂ is too small, a high-purity glass raw material must be used, which leads to an increase in batch cost.

Fe ₂ O ₃ is a component that reduces the transmittance in the deep ultraviolet region. The content of Fe ₂ O ₃ is preferably 100 ppm or less, 80 ppm or less, 60 ppm or less, 40 ppm or less, 20 ppm or less, 10 ppm or less, and particularly 1 to 8 ppm. If _{the content of Fe 2} O ₃ is too large, the glass is colored and the transmittance in the deep ultraviolet region tends to decrease. If _{the content of Fe 2} O ₃ is too small, a high-purity glass raw material must be used, which leads to an increase in batch cost.

Fe ions in iron oxide exist in the state of ^{Fe 2+} or Fe ^3+. If ^{the proportion of Fe 2+} is too small, in other words, if ^{the proportion of Fe 3+} is large, the absorption rate of deep ultraviolet light becomes high, and the transmittance in deep ultraviolet light tends to decrease. Therefore, ^{the mass ratio of Fe 2+} / (Fe ²⁺ + Fe ³⁺ ) in iron oxide is preferably 0.1 or more, 0.2 or more, 0.3 or more, 0.4 or more, and particularly 0.5 or more.

TiO ₂ is a component that reduces the transmittance in the deep ultraviolet region. The content of TiO ₂ is preferably 100 ppm or less, 80 ppm or less, 60 ppm or less, 40 ppm or less, 20 ppm or less, 10 ppm or less, and particularly 0.5 to 5 ppm. If _{the content of TiO 2} is too high, the glass is colored and the transmittance in the deep ultraviolet region tends to decrease. If _{the content of TiO 2} is too small, a high-purity glass raw material must be used, which leads to an increase in batch cost.

Sb ₂ O ₃ is a component that acts as a fining agent. The content of Sb ₂ O ₃ is preferably 1000 ppm or less, 800 ppm or less, 600 ppm or less, 400 ppm or less, 200 ppm or less, 100 ppm or less, and particularly less than 50 ppm. If _{the content of Sb 2} O ₃ is too large, the transmittance in the deep ultraviolet region tends to decrease.

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

F ₂ , Cl ₂ and SO ₃ are components that act as fining agents. The content of F ₂ + Cl ₂ + SO ₃ is preferably 10 to 10000 ppm. Suitable lower limit range of F ₂ + Cl ₂ + SO ₃ is 10 ppm or more, 20 ppm or more, 50 ppm or more, 100 ppm or more, 300 ppm or more, especially 500 ppm or more, and suitable upper limit range is 3000 ppm or less, 2000 ppm or less, 1000 ppm or less, especially 800 ppm or less. Is. Further, _{suitable lower limit ranges of F 2} , Cl ₂ and SO ₃ are 10 ppm or more, 20 ppm or more, 50 ppm or more, 100 ppm or more, 300 ppm or more, particularly 500 ppm or more, and suitable upper limit ranges are 3000 ppm or less and 2000 ppm or less. It is 1000 ppm or less, particularly 800 ppm or less. If the content of these components is too small, it becomes difficult to exert the clarification effect. On the other hand, if the content of these components is too large, the clear gas may remain as bubbles in the glass.

Next, a method of manufacturing the protective cap 2 included in the light emitting device 1 configured as described above will be described.

As shown in FIGS. 4A to 4F, the methods for manufacturing the protective cap 2 according to the first embodiment are the preparation step S1 (FIG. 4A) and the first protective mask forming step S2 (FIG. 4A). (B)), the first etching step S3 (the same figure (c)), the second protective mask forming step S4 (the same figure (d)), and the second etching step S5 (the same figure (e)). It includes a cutting step S6 (FIG. (f)). In this embodiment, a case where a plurality of protective caps 2 are manufactured from the glass base material 12 is illustrated, but the present invention is not limited to this. That is, only one protective cap 2 may be manufactured from the glass base material 12.

As shown in FIG. 4A, in the preparation step S1, a plate-shaped glass base material 12 having a pair of the first main surface 12a and the second main surface 12b is prepared. The glass base material 12 can be formed by, for example, a down draw method such as an overflow down draw method, a slot down draw method, or a redraw method, a float method, or a method of slicing an ingot. When the glass base material 12 is formed by the overflow down draw method, it is preferable because both the first main surface 12a and the second main surface 12b are smooth fire-made surfaces.

When the glass base material 12 is molded from a glass ingot, for example, after inflowing and solidifying molten glass into a mold made of carbon or the like, it is cut into a plate shape with a wire saw or a blade slicer, and a rough polishing step, a mirror polishing step, etc. A plate-shaped glass base material 12 can be obtained. In this case, the first main surface 12a and the second main surface 12b of the glass base material 12 are each composed of a polished surface.

As shown in FIG. 4B, in the first protective mask forming step S2, the first protective film 14 is formed as the first protective mask in the portion of the first main surface 12a excluding the formation region of the first concave portion 13. Will be done.

As shown in FIG. 4C, in the first etching step S3, a plurality of first recesses 13 are formed in the first main surface 12a of the glass base material 12 by etching with an etching solution (for example, hydrofluoric acid). To form. Each of the first recesses 13 constitutes the inner surfaces 5a, 6a, 7a of the side wall portion 5, the lid portion 6, and the corner portion 7 of one protective cap 2. In the first etching step S3, a part of the first main surface 12a is protected from the etching solution by the first protective film 14, so that the region of the first main surface 12a where the first recess 13 is formed (the first protective film). Only 14 non-formed regions) are etched. As a result, the inner surfaces 5a, 6a, and 7a of the side wall portion 5, the lid portion 6, and the corner portion 7 of the protective cap 2 corresponding to the first recess 13 are formed of etched surfaces. Further, the joint opening end 5c of the side wall portion 5 of the protective cap 2 corresponding to the portion excluding the formed region of the first recess 13 is formed of a non-etched surface such as an original polished surface or a fire-made surface without being etched. Etching.

As shown in FIG. 4D, in the second protective mask forming step S4, the second protective film 16 is formed as the second protective mask in the portion of the second main surface 12b excluding the formation region of the second recess 15. Will be done.

As shown in FIG. 4 (e), in the second etching step S5, the first recesses 13 on the second main surface 12b of the glass base material 12 are formed by etching with an etching solution (for example, hydrofluoric acid). A second recess 15 is formed at a position corresponding to the periphery of the. Each second recess 15 constitutes the outer surface 7b of the corner portion 7 of the protective cap 2. In the second etching step S5, a part of the second main surface 12b is protected from the etching solution by the second protective film 16, so that the region of the second main surface 12b where the second recess 15 is formed (second protective film). Only 16 non-formed regions) are etched. As a result, the outer surface 7b of the corner portion 7 of the protective cap 2 corresponding to the second recess 15 is composed of an etched surface. Further, the outer surface 6b of the lid portion 6 of the protective cap 2 corresponding to the portion of the second main surface 12b excluding the formation region of the second concave portion 15 is the original polished surface or fire left unetched. It is composed of non-etched surfaces such as built-up surfaces.

Here, in the first etching step S3 and the second etching step S5, since the recesses 13 and 15 are formed only by etching, the surfaces of the recesses 13 and 15 become very smooth. That is, the arithmetic mean roughness Ra of the surfaces of the recesses 13 and 15 becomes very small. On the other hand, for example, when the concave portion is roughened by machining such as a drill, a reamer, or sandblast, and then the surface of the concave portion is finished by etching, it is affected by the unevenness of the concave surface formed by the rough processing. The smoothness of the concave surface deteriorates. Therefore, the recesses 13 and 15 are preferably formed only by etching.

The first etching step S3 and the second etching step S5 may be performed separately or at the same time. When the first etching step S3 and the second etching step S5 are performed separately, any of the steps may be performed first. In this case, for example, even if one main surface of the glass base material 12 is immersed in the etching solution, the front and back surfaces of the glass base material 12 are inverted, and the other main surface of the glass base material 12 is immersed in the etching solution. Good. When the first etching step S3 and the second etching step S5 are performed at the same time, for example, the entire glass base material 12 may be immersed in an etching solution for etching. In the first etching step S3 and the second etching step S5, etching may be performed by another method such as applying an etching solution.

In the first etching step S3 and the second etching step S5, the depth and width of the recesses 13 and 15 can be adjusted by adjusting the forming pattern and the etching time of the protective films 14 and 16.

The first protective mask forming step S2 and the second protective mask forming step S4 may be performed together before the first etching step S3 and the second etching step S5. That is, the first protective film 14 and the second protective film 16 are formed in advance on both main surfaces 12a and 12b of the glass base material 12, and then the first etching step S3 and the second etching step S5 are started. You may.

The first protective film 14 and the second protective film 16 are peeled off by a release agent (for example, an alkaline chemical) after the completion of the first etching step S3 and the second etching step S5. The first protective film 14 and the second protective film 16 are made of a so-called mask material. As the mask material, for example, a resist made of a synthetic resin, a metal mask made of a metal material, or the like can be used.

As shown in FIG. 4 (f), in the cutting step S6, the glass base material 12 is fully cut (cut and separated) at a position corresponding to the bottom of each of the second recesses 15 by a cutter 17 such as a diamond blade. As the cutter 17, any cutting means such as wire saw cutting, laser cutting, and etching cutting can be used in addition to the diamond blade.

The outer surface 5b of the side wall portion 5 of the protective cap 2 is composed of a cut surface, but the cut surface may be etched after cutting in order to remove defects that may cause damage. That is, the outer surface 5b of the side wall portion 5 of the protective cap 2 may be composed of an etched surface.

(Second Embodiment)
As shown in FIG. 5, in the second embodiment, a method of manufacturing the protective cap 2 in the case of forming the metallized layer 8 and the solder layer 9 on the joint opening end 5c of the protective cap 2 is illustrated.

The method for manufacturing the protective cap 2 according to the present embodiment includes a preparation step T1, an etching step T2, a metallize layer forming step T3, a solder layer forming step T4, and a cutting step T5 in this order. The preparation step T1, the etching step (including the first etching step and the second etching step) T2, and the cutting step T5 are the same as the corresponding steps described in the first embodiment.

In the metallized layer forming step T3 and the solder layer forming step T4, the patterns of the metallized layer 8 and the solder layer 9 are formed on the glass base material 12 with reference to the positions of the recesses 13 and 15 formed by etching.

In this way, the solder layer forming step T4 is performed after the etching step T2. Therefore, the flux contained in the solder layer 9 elutes into the etching solution (for example, hydrofluoric acid) or the stripping solution for the protective films 14 and 16 (for example, alkaline chemicals), and the effect of the solder layer 9 is lost. It can be reliably prevented.

Other configurations in this embodiment are the same as those in the first embodiment. In the present embodiment, components common to the first embodiment are designated by a common reference numeral.

(Third Embodiment)
As shown in FIG. 6, in the third embodiment, a method of manufacturing the protective cap 2 in the case of forming the metallized layer 8 and the solder layer 9 on the joint opening end 5c of the protective cap 2 is illustrated.

The method for manufacturing the protective cap 2 according to the present embodiment includes a preparation step U1, a metallize layer forming step U2, an etching step U3, a solder layer forming step U4, and a cutting step U5 in this order. The preparation step U1, the etching step U3, and the cutting step U5 are the same as the corresponding steps described in the first embodiment.

In the etching step U3, the protective films 14 and 16 are formed on the glass base material 12 based on the pattern of the metallized layer 8. In the solder layer forming step U4, the pattern of the solder layer 9 is formed with reference to the patterns of the metallized layer 8 and / or the positions of the recesses 13 and 15 formed by etching.

In this way, since the solder layer forming step U4 is performed after the etching step U3, the solder layer 9 can be reliably protected for the same reason described in the second embodiment. On the other hand, the metallized layer forming step U2 is performed before the etching step U3, but the metallized layer 8 is often resistant to the etching solution and the stripping solution used in the etching step U3. Therefore, the metallized layer forming step U2 may be performed before the etching step U3. In this case, since the metallized layer 8 can be used as a protective mask, the formation of the first protective film 14 in the etching step U3 can be omitted. When the metallizing layer forming step U2 is performed before the etching step U3, the first protective film 14 may be formed on the metallizing layer 8.

Other configurations in this embodiment are the same as those in the first embodiment. In the present embodiment, components common to the first embodiment are designated by a common reference numeral.

(Fourth Embodiment)
As shown in FIG. 7, in the fourth embodiment, a method of manufacturing the protective cap 2 in the case of forming a resin adhesive layer on the joint opening end 5c of the protective cap 2 is illustrated.

The method for manufacturing the protective cap 2 according to the present embodiment includes a preparation step V1, an etching step V2, a resin adhesive layer forming step V3, and a cutting step V4 in this order. The preparation step V1, the etching step V2, and the cutting step V4 are the same as the corresponding steps described in the first embodiment.

In the resin adhesive layer forming step V3, a pattern of the resin adhesive layer (not shown) is formed on the glass base material 12 with reference to the positions of the recesses 13 and 15 formed by etching. In this case, when the protective cap 2 is adhered to the base material 3, a resin adhesive layer is used instead of the solder layer 9.

(Fifth Embodiment)
As shown in FIG. 8, the light emitting device 1 according to the fifth embodiment is different from the light emitting device 1 according to the first embodiment in the configuration of the base material 3.

In the present embodiment, the base material 3 has a container shape having a bottom surface portion 3a and a frame portion 3b. That is, in the above embodiment, the case where the base material 3 to which the protective cap 2 is bonded has a flat plate shape is illustrated, but the configuration of the base material 3 is not limited to this and can be changed as appropriate.

Other configurations in this embodiment are the same as those in the first embodiment. In the present embodiment, components common to the first embodiment are designated by a common reference numeral.

The present invention is not limited to the configuration of the above-described embodiment, and is not limited to the above-mentioned action and effect. The present invention can be modified in various ways without departing from the gist of the present invention.

In the above embodiment, the light emitting element 4 is exemplified as the electronic component housed inside the protective cap 2, but the electronic component housed inside the protective cap 2 is not limited to this. That is, for example, it can be used not only for a light emitting element but also for an electronic component such as a piezoelectric element and a crystal oscillator. Specifically, it can be used as an electronic component package including a protective cap, a base material to which the protective cap is joined, and an electronic component housed in a space surrounded by the protective cap and the base material.

In the above embodiment, the case where the protective films 14 and 16 having a predetermined hole pattern are formed as the protective mask is illustrated, but the plate or sheet on which the predetermined hole pattern is formed is formed on the main surfaces 12a and 12b of the glass base material 12. The protective mask may be configured by placing or pasting it.

1 Light emitting device 2 Protective cap 3 Base material 4 Light emitting element 5 Side wall part 5c Joint opening end 6 Lid part 7 Square part 8 Metallized layer 9 Solder layer 10 First concave surface part 11 Second concave surface part 12 Glass base material 13 First concave part 14 First protective film 15 Second recess 16 Second protective film S1 Preparation step S2 First protective mask forming step S3 First etching step S4 Second protective mask forming step S5 Second etching step S6 Cutting step

Claims (17)

A protective cap made of glass having a tubular side wall portion having a joint opening end at a base end, a lid portion provided on the tip end side of the side wall portion, and a corner portion connecting the side wall portion and the lid portion. And
The inner surface of the corner portion has a first concave surface portion recessed toward the outer surface of the corner portion, and also has a first concave surface portion.
A protective cap characterized in that the outer surface of the corner portion has a second concave surface portion recessed toward the inner surface of the corner portion. The protective cap according to claim 1, wherein the inner peripheral edge of the second concave surface portion is located within a range defined by the inner peripheral edge of the joint opening end when viewed from the tubular axis direction of the side wall portion. A claim in which the outer peripheral edge of the second concave surface portion is located within a range from the inner surface of the lid portion to the joint opening end when viewed from a direction orthogonal to the tubular axis direction of the side wall portion. Item 2. The protective cap according to item 1 or 2. The protective cap according to any one of claims 1 to 3, wherein each of the first concave surface portion and the second concave surface portion is composed of an etched surface. The protective cap according to any one of claims 1 to 4, wherein the arithmetic average roughness Ra of each of the first concave surface portion and the second concave surface portion is 100 nm or less. Any of claims 1 to 5, wherein the outer surface of the lid portion constituting the top of the protective cap is a polished surface or a fire-made surface, and the arithmetic average roughness Ra of the outer surface of the lid portion is 100 nm or less. The protective cap described in item 1. The protective cap according to any one of claims 1 to 6, wherein the glass is an ultraviolet transmissive glass having a thickness of 0.7 mm and an internal transmittance of 10% or more at a wavelength of 200 nm. The protective cap according to any one of claims 1 to 7, wherein a metallized layer is formed at the joint opening end. The protective cap according to claim 8, wherein a solder layer is formed at the connection opening end via the metallized layer. The protective cap according to any one of claims 1 to 9, the base material to which the joint opening end of the protective cap is joined, and the space surrounded by the protective cap and the base material are housed. A light emitting device including a light emitting element. The light emitting device according to claim 10, wherein the light emitting element is an ultraviolet LED element. A protective cap made of glass having a tubular side wall portion having a joint opening end at a base end, a lid portion provided on the tip end side of the side wall portion, and a corner portion connecting the side wall portion and the lid portion. It is a manufacturing method of
A method for manufacturing a protective cap, which comprises an etching step of forming a first concave surface portion on the inner surface of the corner portion by etching and forming a second concave surface portion on the outer surface of the corner portion by etching. A protective cap made of glass having a tubular side wall portion having a joint opening end at a base end, a lid portion provided on the tip end side of the side wall portion, and a corner portion connecting the side wall portion and the lid portion. It is a manufacturing method of
A preparatory process for preparing a plate-shaped glass base material having a pair of first and second main surfaces,
A first etching step of forming a first recess forming the inner surfaces of the side wall portion, the lid portion and the corner portion of the protective cap on the first main surface of the glass base material by etching.
A second etching step of forming a second recess forming the outer surface of the corner of the protective cap by etching at a position corresponding to the periphery of the first recess on the second main surface of the glass base material.
A method for manufacturing a protective cap, which comprises a cutting step of cutting the glass base material at a position corresponding to the second recess. The first main surface and the second main surface of the glass base material are composed of a polished surface or a fire-made surface.
Before etching in the first etching step, a first protective mask is formed in advance so that a portion of the first main surface of the glass base material other than the region where the first recess is formed is not etched.
A claim in which a second protective mask is formed in advance so that a portion of the second main surface of the glass base material other than the region where the second recess is formed is not etched before etching is performed in the second etching step. 13. The method for manufacturing a protective cap according to 13. The method for manufacturing a protective cap according to claim 14, wherein a metallized layer is formed on the first main surface as the first protective mask. The method for manufacturing a protective cap according to any one of claims 13 to 15, wherein the first recess and the second recess are dug only by etching. The method for manufacturing a protective cap according to any one of claims 13 to 16, wherein the glass base material is formed into a plate shape by an overflow down draw method.

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