JP7405031B2 - Electronic device and method for manufacturing electronic device - Google Patents

Description

The present invention relates to an electronic device and a method of manufacturing the electronic device.

Electronic devices equipped with electronic components such as LEDs have come to be used in various fields such as lighting and communications due to their long lifespan and energy saving.

In this type of light emitting device, in order to protect the electronic components, the base material on which the electronic components are mounted is sometimes covered with a protective cap so that the electronic components are housed inside.

For example, as disclosed in Patent Document 1, the protective cap includes a frame portion (second member) that surrounds the light emitting element, and a lid portion (cover member) that covers an opening at one end of the frame portion. .

International Publication No. 2015/190242

The frame portion of the protective cap and the base material on which electronic components are mounted are often joined using a brazing material (for example, gold-tin solder). The base material is comprised of metal or metal nitride ceramics and is often a high coefficient of expansion material. On the other hand, the frame is made of a transparent inorganic material such as glass, and may be made of a material with a low coefficient of expansion. In such a case, the difference in coefficient of thermal expansion between the base material and the frame becomes large, and it is difficult to select a brazing material that matches the coefficients of thermal expansion of both the base material and the frame. In other words, when the coefficient of thermal expansion of the brazing filler metal is matched to that of the base material, the difference in the coefficient of thermal expansion between the frame and the brazing filler metal increases; and the difference in thermal expansion coefficient between the brazing filler metal and the brazing filler metal increases. As a result, residual stress is generated at or near the joint between the base material and the frame, and damage (for example, cracking) is likely to occur. If the joint or the vicinity thereof is damaged in this manner, the airtightness of the space in which the electronic component is accommodated may deteriorate, and the electronic component may deteriorate.

An object of the present invention is to provide an electronic device that can maintain high airtightness.

The present invention, which was created to solve the above problems, includes an electronic component, a base material on which the electronic component is mounted, and a protective cap bonded to the base material so that the electronic component is housed inside. In the electronic device, the protective cap includes a frame made of a first transparent inorganic material and a lid made of a second transparent inorganic material that covers an opening at one end of the frame. is characterized by being directly welded. In this way, since no other member is interposed between the frame and the base material, even if the difference between the coefficient of thermal expansion of the frame and the coefficient of thermal expansion of the base material is large to some extent, the frame and base material can be reliably joined.

In the above configuration, it is preferable that the frame portion and the lid portion are directly welded. In this way, since there is no other material (high expansion brazing material, adhesive, etc.) interposed between the frame and the lid, the difference between the thermal expansion coefficient of the frame and the lid can be reduced. Even if the size is large to some extent, the frame and the lid can be reliably joined.

In the above configuration, the first transparent inorganic material is preferably quartz glass. This increases the transmittance of ultraviolet rays through the lid, which is particularly effective when the electronic component is an element that emits or receives ultraviolet rays. Note that "quartz glass" refers to an amorphous body including synthetic quartz, fused silica, etc., and containing 90% by mass or more of SiO ₂ .

In the above configuration, it is preferable that the second transparent inorganic material is a glass material having a softening point of 1000° C. or lower. In this way, for example, when the frame and the base material are directly welded by laser bonding or the like, the frame can be easily softened. Therefore, it is possible to soften the frame side and shorten the bonding time between the lid and the frame. For the same reason, when the frame and the lid are directly welded by laser welding or the like, for example, the frame easily softens, so the time for joining the frame and the lid can be shortened. Here, the "softening point" refers to a value measured based on the method of ASTM C338.

In the above configuration, the second transparent inorganic material may be quartz glass. This increases the transmittance of ultraviolet rays through the frame. Therefore, it is particularly effective when the electronic component is an element that emits or receives ultraviolet light.

In the above configuration, the electronic component may be an ultraviolet LED.

The present invention, which was created to solve the above problems, includes an electronic component, a base material on which the electronic component is mounted, and a protective cap bonded to the base material so that the electronic component is housed inside. The protective cap includes a frame made of a first transparent inorganic material and a lid made of a second transparent inorganic material that covers an opening at one end of the frame, The present invention is characterized by comprising a joining step of directly welding the frame and the base material by irradiating the contact portion of the frame and the base material with a laser while the materials are in contact with each other. In this way, since no other member is interposed between the frame and the base material, even if the difference between the coefficient of thermal expansion of the frame and the coefficient of thermal expansion of the base material is large to some extent, the frame and base material can be reliably joined. Furthermore, since the contact portion between the frame portion and the base material is locally heated by the laser, it is also possible to use materials with low heat resistance for components of electronic devices such as electronic components.

The above configuration further includes a joining step of directly welding the frame and the lid by irradiating a laser to a contact portion between the frame and the lid while the frame and the lid are in contact with each other. There is. In this way, since no other member is interposed between the frame and the lid, even if the difference between the coefficient of thermal expansion of the frame and the coefficient of thermal expansion of the lid is large to some extent, the frame and the lid can be can be reliably joined.

According to the present invention, it is possible to provide an electronic device that can maintain high airtightness.

FIG. 1 is a sectional view showing an electronic device according to a first embodiment. 2 is a sectional view taken along line AA in FIG. 1. FIG. 1 is a graph showing transmittance curves of BU-41 and quartz glass at wavelengths of 200 to 600 nm. FIG. 3 is a cross-sectional view showing a manufacturing process of the electronic device according to the first embodiment. FIG. 3 is a cross-sectional view showing a manufacturing process of the electronic device according to the first embodiment. FIG. 3 is a cross-sectional view showing a manufacturing process of the electronic device according to the first embodiment. FIG. 3 is a cross-sectional view showing a manufacturing process of the electronic device according to the first embodiment. FIG. 3 is a cross-sectional view showing a manufacturing process of the electronic device according to the first embodiment. FIG. 3 is a sectional view showing an electronic device according to a second embodiment. It is a sectional view showing an electronic device concerning a third embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that redundant explanation may be omitted by assigning the same reference numerals to corresponding components in each embodiment. When only a part of the configuration is described in each embodiment, the configuration of the other embodiments previously described can be applied to other parts of the configuration. Furthermore, in addition to the combinations of configurations specified in the description of each embodiment, configurations of a plurality of embodiments may be partially combined even if not explicitly specified, as long as no particular problem arises in the combination.

(First embodiment)
1 and 2 illustrate an electronic device 1 according to a first embodiment of the present invention.

The electronic device 1 according to the present embodiment includes an electronic component 2, a base material 3 on which the electronic component 2 is mounted, and a protective cap 4 disposed on the base material 3 so as to accommodate the electronic component 2 therein. It includes a joint portion 5 for joining the base material 3 and the protective cap 4. In addition, in the following description, for convenience, the base material 3 side is explained as the bottom, and the protective cap 4 side is explained as the top, but the up-down direction is not limited to this.

Although the electronic component 2 is not particularly limited, examples thereof include optical devices such as a laser module, an LED, an optical sensor, an image sensor, and an optical switch. In this embodiment, the electronic component 2 is an ultraviolet LED, and the electronic device 1 is a light emitting device.

The base material 3 is made of, for example, metal, metal oxide ceramics, LTCC, or metal nitride ceramics. Examples of the metal include copper and metallic silicon. Examples of metal oxide ceramics include aluminum oxide. Examples of LTCC include those obtained by sintering a composite powder containing crystalline glass and a refractory filler. Examples of metal nitride ceramics include aluminum nitride. In this embodiment, the base material 3 is made of aluminum nitride. The thermal expansion coefficient of aluminum nitride in the temperature range of 30 to 380°C is, for example, 46×10 ⁻⁷ /°C. Moreover, in this embodiment, the base material 3 is a plate-shaped body in which both the upper surface 3a and the lower surface 3b are made of flat surfaces. Note that the base material 3 may be provided with a recessed portion in a portion of the upper surface 3a on which the electronic component 2 is mounted.

The protective cap 4 includes a frame portion 6, a lid portion 7 that covers an opening at one end of the frame portion 6, and a joint portion 8 that joins the frame portion 6 and the lid portion 7. Note that it is preferable to form various functional films on the surface of the protective cap 4. For example, in order to reduce light reflection loss, it is preferable to form an antireflection film.

The frame portion 6 is a cylindrical body having a through hole H extending in the thickness direction (vertical direction) at the center. The frame portion 6 surrounds the electronic component 2 housed in the space corresponding to the through hole H. In the illustrated example, the frame portion 6 is configured as a rectangular tube, but may have other shapes such as a cylinder. In addition, the inner wall surface 6c of the frame portion 6 shifts from the inside to the outside as it goes from the lower end surface 6b side to the upper end surface 6a side of the frame portion 6, in order to improve the extraction efficiency of ultraviolet rays through the lid portion 7. It consists of a sloped surface. The inner wall surface 6c may be a non-inclined surface (vertical surface). The through hole H can be formed by performing etching, laser processing, sandblasting, etc. on the original material of the frame portion 6.

The frame portion 6 is made of a first transparent inorganic material. Examples of the first transparent inorganic material include quartz glass (silica glass) and glass materials other than quartz glass. Quartz glass has high ultraviolet transmittance. Here, "transparent" in the first transparent inorganic material and the second transparent inorganic material (described later) means that, for example, light emitted from the electronic component 2 made of a light emitting element is transmitted. More specifically, it means that the transmittance of light in the target wavelength range is 10% or more. The transmittance can be measured using UH4150 manufactured by Hitachi High-Tech Science.

When the frame portion 6 is made of a glass material other than quartz glass, it is preferable that the glass material is also ultraviolet-transmissive glass. Hereinafter, glass materials other than quartz glass may be simply referred to as glass materials.

In the glass material of the frame part 6, the transmittance at an optical path length of 0.7 mm and a wavelength of 200 nm is preferably 10% or more, 20% or more, 30% or more, 40% or more, 50% or more, 60% or more, or 70% or more. , particularly preferably 80% or more. Further, in the glass material of the frame portion 6, the transmittance at an optical path length of 0.7 mm and a wavelength of 250 nm is preferably 50% or more, 60% or more, 70% or more, particularly preferably 80% or more. Furthermore, in the glass material of the frame 6, when the transmittance at an optical path length of 0.7 mm and a wavelength of 250 nm is T ₂₅₀ , and the transmittance at an optical path length of 0.7 mm and a wavelength of 300 nm is T ₃₀₀ , T ₂₅₀ /T ₃₀₀ The value of is preferably 0.3 or more, 0.4 or more, 0.5 or more, 0.6 or more, 0.7 or more, 0.8 or more, 0.85 or more, particularly preferably 0.9 or more. . In this way, although the transmittance of ultraviolet rays is inferior to that of quartz glass, the light emitted from the electronic component 2 made of ultraviolet LEDs can be transmitted without any problem, and the efficiency of extracting ultraviolet rays can be maintained at a high level. can. Note that "optical path length 0.7 mm" means that even when the thickness of the glass material is thin, an equivalent measurement sample having an optical path length of 0.7 mm is prepared and then subjected to measurement. Note that "transmittance at an optical path length of 0.7 mm and a wavelength of 200 nm" may be measured after preparing a measurement sample with a thickness of 0.7 mm. After measuring the transmittance in the thickness direction of the glass material, A value converted to a length of 0.7 mm may be used.

The strain point of the glass material of the frame portion 6 is preferably 430°C or higher, 460°C or higher, 480°C or higher, 500°C or higher, 520°C or higher, 530°C or higher, 550°C or higher, 600°C or higher, and particularly preferably 630°C or higher. ℃ or higher. If the strain point is too low, there is a risk that distortion will occur in the frame portion 6 during laser bonding, which will be described later, but this can be suppressed by setting the strain point within the above numerical range. Here, the "strain point" is a value measured based on the method of ASTM C336.

The softening point of the glass material of the frame portion 6 is preferably 1000°C or lower, 950°C or lower, 900°C or lower, 850°C or lower, particularly preferably 800°C or lower. In this way, when the frame portion 6 and the lid portion 7 or the frame portion 6 and the base material 3 are directly welded by laser bonding or the like, the frame portion 6 is easily softened, so that the welding time can be shortened. can.

In the glass material of the frame portion 6, the temperature at 10 ^2.5 dPa·s is preferably 1580°C or lower, 1550°C or lower, 1520°C or lower, 1500°C or lower, 1480°C or lower, particularly 1470°C or lower. If the temperature at 10 ^2.5 dPa·s is too high, the meltability will decrease and the manufacturing cost of glass will tend to rise. Here, the "temperature at 10 ^2.5 dPa·s" can be measured by the platinum ball pulling method. Note that the temperature at 10 ^2.5 dPa·s corresponds to the melting temperature, and the lower this temperature is, the better the melting property is.

The thermal expansion coefficient of the glass material of the frame 6 in the temperature range of 30 to 380°C is preferably 30×10 ⁻⁷ /°C or higher, 40×10 ⁻⁷ /°C or higher, 50×10 ⁻⁷ /°C or higher, It is 60×10 ⁻⁷ /°C or more, particularly preferably 70×10 ⁻⁷ /°C or more. Further, the thermal expansion coefficient of the glass material of the frame 6 in the temperature range of 30 to 380°C is preferably 105×10 ^-7 /°C or less, 100×10 ^-7 /°C or less, 95×10 ^-7 /°C or less , particularly preferably 90×10 ⁻⁷ /°C or less. If the coefficient of thermal expansion is too low, it will be difficult to match the coefficient of thermal expansion of various members, especially glass frit. As a result, it becomes difficult to lower the melting point of the glass frit, leading to an increase in temperature during the manufacturing process of the electronic device 1, and the performance of the electronic device 1 is likely to deteriorate. On the other hand, if the coefficient of thermal expansion is too high, the frame portion 6 will be easily damaged due to thermal shock. Note that the thermal expansion coefficient of quartz glass in the temperature range of 30 to 380°C is, for example, 4.0×10 ⁻⁷ /°C. Here, the "thermal expansion coefficient in the temperature range of 30 to 380°C" can be measured using, for example, a dilatometer.

The liquidus temperature of the glass material of the frame portion 6 is preferably less than 1150°C, 1120°C or less, 1100°C or less, 1080°C or less, 1050°C or less, 1030°C or less, 980°C or less, 960°C or less, 950°C or less, Particularly preferably, the temperature is 940°C or lower. Further, the liquidus viscosity of the glass material of the frame portion 6 is preferably 10 ^4.0 dPa·s or more, 10 ^4.3 dPa·s or more, 10 ^4.5 dPa·s or more, or 10 ^4.8 dPa·s. Above, it is 10 ^5.1 dPa·s or more, 10 ^5.3 dPa·s or more, particularly preferably 10 ^5.5 dPa·s or more. In this way, devitrification resistance is improved. Here, the "liquidus temperature" is defined as the glass powder that passes through a standard sieve of 30 mesh (500 μm) and remains on the 50 mesh (300 μm), and is placed in a platinum boat and held in a temperature gradient furnace for 24 hours. This is the value measured by microscopic observation of the precipitation temperature. "Liquidus viscosity" is the value of the viscosity of glass at liquidus temperature measured by the platinum ball pulling method.

The Young's modulus of the glass material of the frame portion 6 is preferably 55 GPa or more, 60 GPa or more, 65 GPa or more, particularly preferably 70 GPa or more. If the Young's modulus is too low, the frame portion 6 is likely to be deformed, warped, or damaged. Here, "Young's modulus" is a value measured by a resonance method.

The glass material of the frame part 6 has a glass composition, in mass %, of 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 25%, MgO + CaO + SrO + BaO 0 It is preferably 25%. The reason why the content of each component was limited as described above is shown below. In addition, in the description of the content of each component, % represents mass % unless otherwise specified. " _{Al2O3 + B2O3} " means _{the total} amount _{of Al2O3} and _B2O3 . " _Li2O + _Na2O + _K2O " means the total amount of _Li2O , _Na2O and _K2O . "MgO+CaO+SrO+BaO" means the total amount of MgO, CaO, SrO and BaO.

SiO ₂ is the main component that forms the skeleton of glass. The content of SiO ₂ is preferably 50-80%, 55-75%, 58-70%, particularly preferably 60-68%. If the content of SiO ₂ is too low, Young's modulus and acid resistance tend to decrease. On the other hand, if the content of _SiO2 is too high, the high-temperature viscosity will increase, the meltability will tend to decrease, and devitrification crystals such as cristobalite will tend to precipitate, causing the liquidus temperature to increase. Become.

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

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

B ₂ O ₃ is a component that improves melting properties and devitrification resistance, and also improves susceptibility to scratches and increases strength. The content of B ₂ O ₃ is preferably 3-25%, 5-22%, 7-19%, especially 9-16%. If the content of B ₂ O ₃ is too small, meltability and devitrification resistance tend to decrease, and 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 high-temperature viscosity, significantly increase meltability, and contribute to initial melting of the glass raw material. The content of Li ₂ O + Na ₂ O + K ₂ O is preferably 0-25%, 1-20%, 4-15%, especially 7-13%. If the content of Li2O+ _Na2O + _K2O is too small, the meltability tends to decrease. On the other hand, if the content of Li ₂ O+Na ₂ O+K ₂ O is too large, the coefficient of thermal expansion may become unduly high.

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

Na ₂ O is a component that lowers high-temperature viscosity, significantly increases meltability, and contributes to initial melting of the glass raw material. It is also a component for adjusting the coefficient of thermal expansion. The content of Na ₂ O is preferably 0-25%, 1-20%, 3-18%, 5-15%, particularly preferably 7-13%. If the content of Na ₂ O is too low, not only the meltability tends to decrease, but also the coefficient of thermal expansion may become unduly low. On the other hand, if the content of Na ₂ O is too large, the coefficient of thermal expansion may become unduly high.

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

MgO, CaO, SrO and BaO are components that lower high temperature viscosity and increase 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 devitrify.

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

CaO is a component that lowers high temperature viscosity and significantly increases meltability. Moreover, among alkaline earth metal oxides, since the raw material to be introduced is relatively inexpensive, it is a component that reduces raw material costs. The CaO content is preferably 0 to 15%, 0.5 to 10%, particularly preferably 1 to 5%. If the content of CaO is too high, the glass tends to devitrify. Note that if the CaO content is too low, it will be difficult to enjoy the above effects.

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

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

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

ZnO is a component that improves meltability, but if it is included in a large amount in the glass composition, the glass tends to devitrify. Therefore, the ZnO content is preferably 0 to 5%, 0 to 3%, 0 to 1%, 0 to less than 1%, particularly preferably 0 to 0.1%.

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

Fe ₂ O ₃ and TiO ₂ are components that reduce transmittance in the deep ultraviolet region. The content of Fe ₂ O ₃ +TiO ₂ is preferably 100 ppm or less, 80 ppm or less, 60 ppm or less, 0.1 to 40 ppm or less, particularly preferably 1 to 20 ppm. If the content of Fe ₂ O ₃ +TiO ₂ is too large, the glass becomes colored and the transmittance in the deep ultraviolet region tends to decrease. Note that if the content of Fe ₂ O ₃ +TiO ₂ is too small, a high purity glass raw material must be used, leading to a rise in batch cost. In addition, " _{Fe2O3 + TiO2} " means the total amount _{of Fe2O3} and _TiO2 .

Fe ₂ O ₃ is a component that reduces transmittance in the deep ultraviolet region. The content of Fe ₂ O ₃ is preferably 100 ppm or less, 80 ppm or less, 60 ppm or less, 40 ppm or less, 20 ppm or less, 10 ppm or less, particularly preferably 1 to 8 ppm. If the content of Fe ₂ O ₃ is too large, the glass will be colored and the transmittance in the deep ultraviolet region will tend to decrease. Note that if the content of Fe ₂ O ₃ is too low, a high purity glass raw material must be used, leading to a rise 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, 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, particularly preferably 0.5 or more. be.

TiO ₂ is a component that reduces 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, particularly preferably 0.5 to 5 ppm. If the content of TiO ₂ is too large, the glass becomes colored and the transmittance in the deep ultraviolet region tends to decrease. Note that if the content of TiO ₂ is too low, a high purity glass raw material must be used, leading to a rise in batch cost.

Sb ₂ O ₃ is a component that acts as a clarifying 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, particularly preferably 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.

_SnO2 is a component that acts as a clarifying 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, particularly preferably 100 ppm or less. If the content of SnO ₂ is too large, 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 10,000 ppm. The preferred lower limit range of _F2 + _Cl2 + _SO3 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 the preferred upper limit range is 3000 ppm or less, 2000 ppm or less, 1000 ppm or less, especially 800 ppm or less. It is. Further, the preferable lower limit ranges of each 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, especially 500 ppm or more, and the preferable upper limit ranges are 3000 ppm or less, 2000 ppm or less, It is 1000 ppm or less, especially 800 ppm or less. If the content of these components is too low, it will be difficult to exhibit the clarification effect. On the other hand, if the content of these components is too large, the clarified gas may remain in the glass as bubbles. In addition, " _F2 + _Cl2 + _SO3 " means the total amount of _F2 , _Cl2 , and _SO3 .

The glass material for the frame portion 6 can be made, for example, by mixing various glass raw materials to obtain a glass batch, then melting this glass batch, clarifying and homogenizing the obtained molten glass, and molding it into a predetermined shape. It can be made with

In the manufacturing process of the glass material of the frame portion 6, it is preferable to use a reducing agent as part of the glass raw material. In this way, Fe ³⁺ contained in the glass is reduced and the transmittance of deep ultraviolet rays is improved. As the reducing agent, materials such as wood powder, carbon powder, metal aluminum, metal silicon, and aluminum fluoride can be used, and among these, metal silicon and aluminum fluoride are preferred.

In the manufacturing process of the glass material of the frame 6, it is preferable to use metal silicon as part of the glass raw material, and the amount added is 0.001 to 3% by mass, 0.005% by mass based on the total mass of the glass batch. -2% by weight, 0.01-1% by weight, particularly 0.03-0.1% by weight are preferred. If the amount of metal silicon added is too small, Fe ³⁺ contained in the glass will not be reduced, and the transmittance of deep ultraviolet rays will tend to decrease. On the other hand, if the amount of metal silicon added is too large, the glass tends to be colored brown.

It is also preferable to use aluminum fluoride (AlF ₃ ) as part of the glass raw material, and the amount added is 0.01 to 5% by mass in terms of F ₂ and 0.05 to 5% by mass based on the total mass of the glass batch. 4% by weight, 0.1 to 3% by weight, 0.2 to 2% by weight, and 0.3 to 1% by weight are preferred. On the other hand, if the amount of aluminum fluoride added is too large, _F2 gas may remain in the glass as bubbles. If the amount of aluminum fluoride added is too small, Fe ³⁺ contained in the glass will not be reduced, and the transmittance of deep ultraviolet light will tend to decrease.

In the manufacturing process of the glass material of the frame portion 6, it is preferable to form the glass material into a flat plate shape by a down-draw method, particularly an overflow down-draw method. In the overflow down-draw method, molten glass overflows from both sides of a heat-resistant gutter-like structure, and the overflowing molten glass joins at the bottom end of the gutter-like structure, stretching downward to form a glass plate. This is the way to do it. In the overflow downdraw method, the surface of the glass plate that is to become the surface does not come into contact with the trough-like refractories and is formed as a free surface. Therefore, it becomes easier to produce a thin glass plate, and variations in plate thickness can be reduced without polishing the surface. As a result, the manufacturing cost of the glass plate can be reduced. Note that the structure and material of the gutter-like structure are not particularly limited as long as desired dimensions and surface accuracy can be achieved. Furthermore, the method of applying force when performing downward stretch molding is not particularly limited. For example, a method may be adopted in which a heat-resistant roll with a sufficiently large width is rotated while in contact with the glass, or a plurality of pairs of heat-resistant rolls are brought into contact only near the end surface of the glass. You may adopt the method of stretching.

As a method for forming the glass material of the frame portion 6, other than the down-draw method, for example, a slot-down method, a redraw method, a float method, etc. can also be adopted.

Specifically, as the glass material for the frame portion 6, for example, BU-41 manufactured by Nippon Electric Glass Co., Ltd. can be used. The thermal expansion coefficient of BU-41 in the temperature range of 30 to 380°C is, for example, 42×10 ⁻⁷ /°C.

The thickness (vertical dimension) of the frame portion 6 is preferably larger than the electronic component 2, preferably 0.01 to 1 mm larger than the electronic component 2, more preferably 0.05 to 0.5 mm larger, Most preferably, it is larger by 0.1 to 0.2 mm.

The lid portion 7 is made of a second transparent inorganic material. As the second transparent inorganic material, those exemplified as the first transparent inorganic material can be similarly applied. The second transparent inorganic material may be made of the same material as the first transparent inorganic material, or may be made of a different material. However, from the viewpoint of extraction efficiency of ultraviolet rays, it is preferable that the lid part 7 is made of quartz glass. In this embodiment, the lid portion 7 is made of quartz glass. Moreover, in this embodiment, the lid part 7 is a plate-shaped body in which both the upper surface 7a and the lower surface 7b are made of flat surfaces.

The thickness (vertical dimension) of the lid portion 7 is preferably 0.1 to 1.0 mm, more preferably 0.2 to 0.8 mm, and preferably 0.3 to 0.6 mm. Most preferred.

In this embodiment, the joint portion 5 that joins the frame portion 6 and the base material 3 is formed from a welded portion 9 in which the frame portion 6 and the base material 3 are directly welded. Similarly, a joining part 8 that joins the frame part 6 and the lid part 7 is also formed from a welded part 10 in which the frame part 6 and the lid part 7 are directly welded. Welded parts 9 and 10 are formed by laser bonding.

Specifically, the welded portion 9 is formed by melting at least one of the frame portion 6 and the base material 3 in the laser irradiation region and then solidifying the melted portion. That is, it is preferable that the welded part 9 is made of at least one material of the frame part 6 and the base material 3, and does not substantially contain any material other than the frame part 6 and the base material 3, for example. Similarly, the welded part 10 is formed by melting at least one of the frame part 6 and the lid part 7 in the laser irradiation area and then solidifying the melted part. That is, it is preferable that the welded part 9 is made of at least one material of the frame part 6 and the lid part 7, and does not substantially contain any material other than the frame part 6 and the lid part 7, for example.

A plurality of welded parts 9 and 10 (two in the illustrated example) are formed in a concentric ring shape along the through hole H, but there may be only one welded part 9 and 10. The plurality of welded parts 9 and 10 are spaced apart from each other in the radial direction, but may overlap in the radial direction. Each of the welded parts 9 and 10 is configured to have a rectangular ring shape in a plan view, but is not limited to this, and may be configured to have a circular or other ring shape.

The welded portion 9 is formed continuously over the frame portion 6 and the base material 3 in the thickness direction. Similarly, the welded portion 10 is formed continuously over the frame portion 6 and the lid portion 7 in the thickness direction. In addition, in this embodiment, there is no interface between the frame 6 and the base material 3 inside the welding part 9, and there is no interface between the frame 6 and the lid part 7 inside the welding part 10. There is no. Of course, the interface may remain inside the welded parts 9 and 10.

The width S1 of the welded parts 9, 10 is preferably 10 to 200 μm, more preferably 10 to 100 μm, and most preferably 10 to 50 μm. The thickness S2 of the welded parts 9 and 10 is preferably 10 to 200 μm, more preferably 10 to 150 μm, and most preferably 10 to 100 μm.

The maximum value of the residual stress in the planar direction of the welded parts 9 and 10 is preferably 10 MPa or less, more preferably 7 MPa or less, and most preferably 5 MPa or less. The maximum value of the residual stress in the plane direction is determined by measuring the birefringence (unit: nm) near the joint using UniOpto's birefringence measuring machine: ABR-10A on a glass plate with dimensions of 10 mm x 10 mm or more. This is the maximum value when converted to residual stress in the plane direction. In addition, by measuring optical birefringence, that is, measuring the optical path difference between orthogonal linearly polarized waves, it is possible to estimate the residual stress value in the glass plate, and the deviatoric stress F (MPa) caused by the residual stress can be calculated. , F=D/CW. "D" is the optical path difference (nm), "W" is the distance (cm) that the polarized wave has passed, and "C" is the photoelastic constant (proportionality constant), which is usually 20 to 40 (nm/ cm)/(MPa). Note that the residual stress in the planar direction includes tensile stress and compressive stress, and in the above, the absolute values of both are evaluated.

FIG. 3 shows transmittance curves of BU-41 (manufactured by Nippon Electric Glass Co., Ltd.) and quartz glass at wavelengths of 200 to 600 nm. As shown in the figure, silica glass has a transmittance of 90% or more in the deep ultraviolet region (for example, a wavelength range of 200 to 350 nm) without decreasing its transmittance as the thickness increases. On the other hand, BU-41 has a transmittance of 84% or more at a thickness of 0.2 mm and a transmittance of 70% or more at a thickness of 0.5 mm in the deep ultraviolet region. In other words, BU-41 has good transmittance in the deep ultraviolet region, although it is slightly inferior to quartz glass. Specifically, in the state of the electronic device (light emitting device) 1, the ultraviolet ray extraction efficiency (of the electronic component (ultraviolet LED) 2) when both the lid portion 7 and the frame portion 6 are made of quartz glass with a thickness of 0.6 mm is determined. The output magnification) is 89% on average, and when the lid part 7 is made of quartz glass with a thickness of 0.6 mm and the frame part 6 is made of BU-41 with a thickness of 0.6 mm, the extraction efficiency of ultraviolet rays is 88% on average. Met. Therefore, even if the lid part 7 is made of quartz glass and the frame part 6 is made of a glass material other than quartz glass that transmits ultraviolet light (for example, BU-41), the efficiency of extracting light in the ultraviolet region can be maintained at a high level. It can be maintained with However, from the viewpoint of improving the efficiency of extracting ultraviolet rays, it is preferable that both the lid part 7 and the frame part 6 be made of quartz glass.

4 to 7 illustrate a method for manufacturing the electronic device 1 according to the first embodiment of the present invention.

The manufacturing method of the electronic device 1 according to the present embodiment includes a first bonding step of bonding the lid portion 7 and the frame portion 6 to obtain the protective cap 4, and a base material 3 on which the electronic component 2 is mounted and the protective cap 4. and a second joining step of joining the cap 4.

In the first joining step, first, as shown in FIG. 4, the lid part 7 and the frame part 6 are prepared. Next, the lower surface 7b of the lid portion 7 and the upper end surface 6a of the frame portion 6 are brought into direct contact. In this state, as shown in FIG. 5, the laser irradiation device 11 focuses and irradiates the contact portion between the lid portion 7 and the frame portion 6 with the laser L. The laser L is irradiated from at least one side of the lid 7 and the frame 6. In this embodiment, the laser L is irradiated from the lid portion 7 side. Thereby, the contact portion is welded to form the welded portion 10, and the frame portion 6 and the lid portion 7 are joined by the welded portion 10. In this way, since no other member is interposed between the frame part 6 and the lid part 7, even if the difference between the coefficient of thermal expansion of the frame part 6 and the coefficient of thermal expansion of the lid part 7 is large to some extent, The part 6 and the lid part 7 can be reliably joined.

As shown in FIG. 6, the laser L is scanned outside the through hole H so as to draw an annular trajectory T along the through hole H. In this case, the laser L is scanned so that its irradiation area R goes around the annular orbit T while overlapping on the annular orbit T. Alternatively, the laser L is scanned so as to orbit the annular orbit T multiple times. Note that when a plurality of welded portions 10 are formed in a concentric ring shape, a plurality of annular trajectories T on which the laser L scans are also set in a concentric ring shape.

Alternatively, the joint portion may be formed in a frame shape by intersecting four straight lines in a grid pattern so as to surround the through hole H. Thereby, since a plurality of protective caps 4 can be manufactured at once, the manufacturing efficiency of the electronic device 1 can be improved.

In the second bonding step, first, as shown in FIG. 7, the protective cap 4 obtained in the first bonding step and the base material 3 on which the electronic component 2 is mounted are prepared. Next, the lower end surface 6b of the frame portion 6 and the upper surface 3a of the base material 3 are brought into direct contact. In this state, as shown in FIG. 8, the laser irradiation device 11 focuses and irradiates the contact portion of the frame portion 6 and the base material 3 with the laser L. The laser L is irradiated from the frame 6 side of the frame 6 and the base material 3 through which the laser L passes. Thereby, the contact portion is welded to form a welded portion 9, and the frame portion 6 and the base material 3 are joined by the welded portion 9. In this way, since no other member is interposed between the frame part 6 and the base material 3, even if the difference between the coefficient of thermal expansion of the frame part 6 and the coefficient of thermal expansion of the base material 3 is large to some extent, The portion 6 and the base material 3 can be reliably joined.

The arithmetic mean roughness Ra of each of the lower surface 7b of the lid 7, the upper end surface 6a of the frame 6, the lower end surface 6b of the frame 6, and the upper surface 3a of the base material 3 is preferably 2.0 nm or less, and 1 It is more preferably 0.0 nm or less, even more preferably 0.5 nm or less, and most preferably 0.2 nm or less. Arithmetic mean roughness Ra means a value measured by a method based on JIS B0601:2001. In this way, the lid part 7 and the frame part 6, and the frame part 6 and the base material 3 are brought into close contact with each other due to the intermolecular force (optical contact) between the bonding surfaces, so that handling performance before laser bonding is improved.

As the laser L, an ultrashort pulse laser having a pulse width on the order of picoseconds or femtoseconds is preferably used.

The wavelength of the laser L is not particularly limited as long as it is a wavelength that can be transmitted through the glass member, but for example, it is preferably 400 to 1600 nm, more preferably 500 to 1300 nm. The pulse width of the laser L is preferably 10 ps or less, more preferably 5 ps or less, and most preferably 200 fs to 3 ps. The focused diameter of the laser L is preferably 50 μm or less, more preferably 30 μm or less, and preferably 20 μm or less.

The repetition frequency of the laser L needs to be at a level that causes continuous heat accumulation, and specifically, it is preferably 100 kHz or more, more preferably 200 kHz or more, and 500 kHz or more. is even more preferable.

Further, it is preferable to use a method (burst mode) in which one pulse is distributed into a plurality of pulses and the pulse interval is further shortened for irradiation. Thereby, heat accumulation is likely to occur, and the joint portion 8 can be stably formed.

(Second embodiment)
FIG. 9 illustrates an electronic device 1 according to a second embodiment of the present invention. In the second embodiment, the configuration of a joint part 8 that joins the frame part 6 and the lid part 7 is different from the first embodiment.

In this embodiment, the frame portion 6 and the lid portion 7 are made of quartz glass. The joint portion 8 is made up of an adhesive layer 21. That is, the frame part 6 and the lid part 7 are not in direct contact with each other, and the adhesive layer 21 is interposed between them. The adhesive layer 21 is formed, for example, by firing an adhesive.

The thermal expansion coefficient of the adhesive layer 21 in the temperature range of 30 to 380 °C is -25 × 10 ^-7 to 25 × 10 ^-7 / °C, and -20 × 10 ^-7 to 20 × 10 ^-7 / °C. It is preferably -15 x 10 ^-7 to 15 x 10 ^-7 /°C, more preferably -10 x 10 ^-7 to 10 x 10 ^-7 /°C. The coefficient of thermal expansion of quartz glass in the temperature range of 30 to 380°C is, for example, 4.0×10 ⁻⁷ /°C. Therefore, by using the adhesive layer 21 having the above-mentioned coefficient of thermal expansion, the coefficient of thermal expansion of the frame portion 6 and lid portion 7 made of a material with a low expansion coefficient such as quartz glass can be matched with the coefficient of thermal expansion of the adhesive layer 21. can be done. As a result, even if the adhesive layer 21 is used, residual stress generated at or near the adhesive layer 21 can be reduced, and damage to the protective cap 4 (such as cracks) can be suppressed.

Although the thickness of the adhesive layer 21 is not particularly limited, if the thickness of the adhesive layer 21 is too small, the mechanical strength of the adhesive layer 21 tends to decrease. On the other hand, if the thickness of the adhesive layer 21 is too large, the residual stress in the adhesive layer 21 may increase and the mechanical strength may decrease. Furthermore, the sizes of the protective cap 4 and the electronic device 1 tend to increase. Therefore, the thickness of the adhesive layer 21 is preferably 10 μm to 100 μm, more preferably 20 μm to 80 μm, and most preferably 30 μm to 60 μm.

It is preferable that the adhesive layer 21 contains glass. In this way, the heat resistance and airtightness of the adhesive layer 21 can be improved. In particular, if the adhesive layer 21 contains crystallized glass, it will be easier to reduce the expansion, and it will be easier to match the coefficient of thermal expansion with the frame portion 6 and the lid portion 7 made of quartz glass. Specifically, the adhesive layer 21 preferably contains β-quartz solid solution, which is a low expansion crystal. The content of the β-quartz solid solution in the adhesive layer 21 is preferably 75 to 99% by mass, 80 to 97% by mass, particularly 85 to 95% by mass. If the content of the β-quartz solid solution is too small, it tends to be difficult to reduce the expansion of the adhesive layer 21. On the other hand, if the content of β-quartz solid solution is too large, fluidity during bonding tends to decrease. Note that the adhesive layer 21 containing crystallized glass is obtained by heat-treating an adhesive (sealing material) containing crystallized glass.

A specific example of the adhesive layer 21 includes, in terms of mol%, SiO ₂ 48 to 75%, Al ₂ O ₃ 5 to 25%, Li ₂ O 5 to 30%, B ₂ O ₃ 5 to 23%, and ZnO. Examples include those containing glass containing 0 to 10%. In particular, as a composition, in mol%, SiO ₂ 48-75%, Al ₂ O ₃ 5-25%, Li ₂ O 5-30%, B ₂ O ₃ 10-23% (but not including 10%), Glass containing 0 to 2.5% (but not including 2.5%) of ZnO is preferred. The reason for having such a composition will be explained below. In addition, in the description regarding the content of each component below, unless otherwise specified, "%" means "mol%".

SiO ₂ is a component that forms the glass skeleton and is also a component of the β-quartz solid solution. The content of SiO ₂ is preferably 48-75%, 53-70%, particularly 58-65%. If the content of SiO ₂ is too low, the amount of β-quartz solid solution precipitated will be small, making it difficult to obtain low thermal expansion characteristics. On the other hand, if there is too much SiO ₂ , the softening point will increase, so that the softening fluidity due to heat treatment during bonding (sealing) will tend to decrease.

Al ₂ O ₃ is a constituent of the β-quartz solid solution. The content of Al ₂ O ₃ is preferably 5 to 25%, 7 to 15%, particularly 7 to 13%. If the content of Al ₂ O ₃ is too low, the amount of β-quartz solid solution precipitated will be small, making it difficult to obtain low thermal expansion characteristics. On the other hand, if there is too much Al ₂ O ₃ , the softening point will increase, and the softening fluidity due to heat treatment during bonding will tend to decrease.

Li ₂ O is a constituent of the β-quartz solid solution and is a component that lowers the softening point. The content of Li ₂ O is preferably 5 to 30%, 10 to 25%, particularly 10 to 20%. If the Li ₂ O content is too low, the amount of β-quartz solid solution precipitated will be small, making it difficult to obtain low thermal expansion characteristics. Furthermore, since the softening point increases, softening fluidity due to heat treatment during bonding tends to decrease. On the other hand, if the content of Li ₂ O is too large, the content of Li ₂ O in the residual glass after heat treatment will increase, and the coefficient of thermal expansion of the residual glass will become high, making it difficult to obtain low thermal expansion characteristics. Become.

B ₂ O ₃ is a component that forms a glass skeleton and is a component that lowers the softening point. The content of B ₂ O ₃ is preferably 5 to 23%, 10 to 23% (excluding 10%), 12 to 16%, particularly 13 to 15%. If the content of B ₂ O ₃ is too small, the softening point will rise and the difference between the softening point and the crystallization temperature will become small. Therefore, crystals tend to precipitate before softening and flow due to heat treatment during bonding, and fluidity tends to decrease. On the other hand, if the content of B ₂ O ₃ is too high, the proportion of the residual glass phase after heat treatment will increase (the amount of β-quartz solid solution precipitated will decrease), and the thermal expansion coefficient of the residual glass phase will increase. As a result, it becomes difficult to obtain low thermal expansion characteristics.

Note that by appropriately adjusting the ratio of each content of B ₂ O ₃ and Li ₂ O, low thermal expansion characteristics can be easily obtained. Specifically, it is preferable to adjust the value of B ₂ O ₃ /Li ₂ O to 0.5-1, 0.7-1, particularly 0.8-1. In addition, " _B2O3 / _Li2O " means _the molar ratio of each content of _B2O3 and _{Li2O .}

ZnO is a component that improves weather resistance. It also has the effect of improving softening fluidity due to heat treatment during bonding. The content of ZnO is preferably 0 to 10%, 0 to 2.5% (excluding 2.5%), particularly 0 to 2%. If the ZnO content is too high, the amount of β-quartz solid solution precipitated will be reduced, or foreign crystals such as Zn-Al crystals that do not contribute to low expansion will be likely to precipitate. Furthermore, the coefficient of thermal expansion of the glass remaining after heat treatment tends to be high. As a result, the coefficient of thermal expansion tends to increase.

Note that MgO, CaO, SrO, or BaO may be included as a component that improves weather resistance. These components also have the effect of improving softening fluidity due to heat treatment during bonding. The content of MgO+CaO+SrO+BaO is preferably 0 to 10%, 0 to 5%, particularly 0.1 to 2%. If the content of MgO+CaO+SrO+BaO is too large, the amount of β-quartz solid solution precipitated tends to decrease, and the coefficient of thermal expansion of the residual glass phase after heat treatment tends to increase. As a result, the coefficient of thermal expansion tends to increase.

Further, La ₂ O ₃ , ZrO ₂ or Bi ₂ O ₃ may be contained as a component that similarly improves weather resistance. Among these, ZrO ₂ and Bi ₂ O ₃ also have the effect of improving softening fluidity due to heat treatment during bonding. The content of La ₂ O ₃ +ZrO ₂ +Bi ₂ O ₃ is preferably 0 to 10%, 0 to 5%, particularly 0.1 to 2%. If the content of La ₂ O ₃ +ZrO ₂ +Bi ₂ O ₃ is too large, the amount of precipitated β-quartz solid solution tends to decrease, and the coefficient of thermal expansion of the residual glass phase after heat treatment tends to increase. In particular, when the content of La ₂ O ₃ is too high, foreign crystals such as La-B crystals that do not contribute to low expansion tend to precipitate. As a result, the coefficient of thermal expansion tends to increase. In addition, " _La2O3 + _{ZrO2 + Bi2O3 "} means the total amount _{of La2O3 , ZrO2 ,} and _Bi2O3 .

In addition to the above components, the total amount of Na ₂ O, K ₂ O, MnO, P ₂ O ₅ , MoO ₂ , TiO ₂ , V ₂ O ₅ , etc. is 30% or less, within a range that does not impair the effects of the present invention. It can be contained in a range of 20% or less, and even 10% or less.

Note that the adhesive layer 21 may contain a fire-resistant filler powder to adjust the coefficient of thermal expansion. The content of the refractory filler is preferably 0 to 30% by weight, 0.1 to 20% by weight, particularly 1 to 10% by weight. If the content of the refractory filler powder is too large, the bondability to the members to be bonded tends to decrease.

Refractory filler powders include cordierite, willemite, alumina, zirconium phosphate, zircon, zirconia, tin oxide, mullite, silica, β-eucryptite, β-spodumene, β-quartz solid solution, zirconium tungstate phosphate. etc. can be used.

The adhesive constituting the adhesive layer 21 is arranged between the frame portion 6 and the lid portion 7 in the form of powder, green compact, paste, or the like. When the adhesive is a paste, for example, a paste containing crystalline glass powder, a resin, and a solvent is applied. For example, a dispenser can be used to apply the paste.

As the resin for the paste, acrylic esters (acrylic resins), ethyl cellulose, polyethylene glycol derivatives, nitrocellulose, polymethylene styrene, polyethylene carbonate, methacrylic esters, etc. can be used. In particular, acrylic esters and ethyl cellulose are preferred because they have good thermal decomposition properties.

Solvents for the paste include α-terpionelle, pine oil, N,N'-dimethylformamide (DMF), higher alcohol, γ-butyrolactone (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, N-methyl-2-pyrrolidone, etc. can be used. In particular, α-terpionelle is preferred because it has high viscosity and good solubility for resins and the like.

The firing temperature is preferably within a range of ±100°C, particularly ±50°C of the softening point of the adhesive. Specifically, the firing temperature is preferably within the range of, for example, 500°C to 800°C, particularly 600°C to 750°C. If the firing temperature is too low, softening and fluidization will be insufficient and adhesive strength will tend to be poor. On the other hand, if the firing temperature is too high, fluidity tends to be excessive and joining becomes difficult. Furthermore, if the adhesive contains crystalline glass, there is a risk that crystal transition (for example, crystal transition from β-quartz solid solution to β-spodumene solid solution) will occur, resulting in high expansion of the adhesive layer 21. Note that the adhesive may be fired by heating using a heating furnace or by heating using a laser.

The average particle diameter D ₅₀ of the adhesive is preferably 15 μm or less, 0.5 to 10 μm, particularly 0.7 to 5 μm. If the particle size of the average particle diameter _D50 is too large, the adhesive layer 21 obtained after firing will have too many pores, which may reduce the bonding strength. Here, the "average particle diameter _D50 " refers to the value measured with a laser diffraction device, and in the volume-based cumulative particle size distribution curve measured by the laser diffraction method, the cumulative amount is the cumulative amount starting from the smallest particle size. represents the particle size that is 50%.

(Third embodiment)
FIG. 10 illustrates an electronic device 1 according to a third embodiment of the present invention. In the third embodiment, the protective cap 4 is composed of a single member without a joint between the frame part 6 and the lid part 7, and this point is different from the first and second embodiments. The frame portion 6 of the protective cap 4 made of a single member is directly welded to the base material 3 by a welding portion 9 .

Note that the present invention is not limited to the configuration of the embodiments described above, nor is it limited to the effects described above. The present invention can be modified in various ways without departing from the gist of the invention.

In the above embodiment, the lid 7 may be joined to the frame 6 after the frame 6 and the base material 3 are joined. In this case, the electronic component 2 may be mounted on the base material 3 after the frame part 6 and the base material 3 are joined, and then the lid part 7 may be joined to the frame part 6. However, in consideration of workability, it is preferable to mount the electronic component 2 on the base material 3 before joining the frame portion 6 and the base material 3.

In the above embodiment, a reflective film may be formed on the inner peripheral surface of the frame portion 6 in order to improve the efficiency of extracting ultraviolet rays.

1 Electronic device 2 Electronic component 3 Base material 4 Protective cap 5 Joint part 6 Frame part 7 Lid part 8 Joint part 9 Weld part 10 Weld part

Claims (6)

An electronic device comprising an electronic component, a base material on which the electronic component is mounted, and a protective cap joined to the base material so that the electronic component is housed therein, the electronic device comprising:
The protective cap includes a frame portion made of a first transparent inorganic material, and a lid portion made of a second transparent inorganic material that covers an opening at one end of the frame portion,
The frame portion and the base material are directly welded, and
An electronic device characterized in that the frame portion and the lid portion are directly welded . An electronic device comprising an electronic component, a base material on which the electronic component is mounted, and a protective cap joined to the base material so that the electronic component is housed therein, the electronic device comprising:
The protective cap includes a frame portion made of a first transparent inorganic material, and a lid portion made of a second transparent inorganic material that covers an opening at one end of the frame portion,
The frame portion and the base material are directly welded,
An electronic device characterized in that the electronic component is an ultraviolet LED. The electronic device according to claim 1 or 2, wherein the first transparent inorganic material is quartz glass. The electronic device according to any one of claims 1 to 3, wherein the second transparent inorganic material is a glass material having a softening point of 1000° C. or less. The electronic device according to any one of claims 1 to 3, wherein the second transparent inorganic material is quartz glass. A method for manufacturing an electronic device comprising: an electronic component; a base material on which the electronic component is mounted; and a protective cap bonded to the base material so that the electronic component is housed therein.
The protective cap includes a frame portion made of a first transparent inorganic material, and a lid portion made of a second transparent inorganic material that covers an opening at one end of the frame portion,
a joining step of directly welding the frame portion and the base material by irradiating a contact portion between the frame portion and the base material with a laser while the frame portion and the base material are in contact with each other ;
a joining step of directly welding the frame and the lid by irradiating a contact portion between the frame and the lid with a laser while the frame and the lid are in contact with each other; A method of manufacturing an electronic device, characterized in that: