Cover glass with outer frame, semiconductor light emitting device, and semiconductor light receiving device

Abstract

This invention relates to a glass cover with an outer frame, wherein a flat glass plate is directly joined to the outer frame, wherein the glass matrix within the outer frame comprises at least one of bismuth oxide and boron oxide, and the glass ceramic has a coefficient of thermal expansion of 15 × 10⁻⁶. －7 In the glass ceramics described above, the total volume fraction of the negative thermal expansion filler and the total volume fraction of the filler components are both 40% to 65%, and the softening point of the glass components in the glass matrix is ​​lower than the glass transition point of the flat glass.

Description

Technical Field

[0001] This invention relates to a glass cover with an outer frame. Furthermore, this invention also relates to a semiconductor light-emitting device and a semiconductor light-receiving device that are hermetically sealed by the aforementioned glass cover with an outer frame. Background Technology

[0002] Devices using light-emitting diodes (LEDs) are being used in a wide range of applications, including mobile phones, backlights for large LCD TVs, and lighting.

[0003] For example, in the case of light-emitting devices that utilize light-emitting diodes (visible light LEDs) that emit visible light, a configuration is often used in which the LED chip is mounted on a flat substrate, such as aluminum nitride, and sealed with a resin-based component.

[0004] In contrast, light-emitting devices that utilize ultraviolet-emitting diodes (UV-LEDs), laser diodes (LDs), and vertical-cavity surface-emitting lasers (VCSELs) require hermetic sealing. Additionally, VCSELs also require a diffuser plate.

[0005] Therefore, these light-emitting devices require a frame shape on the cover glass. Although the frame can also be provided on a substrate such as aluminum nitride, it is more practical to provide the frame on the cover glass from a cost perspective.

[0006] Not limited to the aforementioned light-emitting devices, hermetic sealing is sometimes also required in light-receiving devices such as sensors. For example, there are devices called MEMS (Micro Electro Mechanical Systems), which are devices that integrate circuits and tiny mechanical structures on a single substrate. Silicon substrates are an example of substrates used in MEMS.

[0007] In light-receiving devices, the same requirement as for light-emitting devices necessitates a frame shape on the cover glass. Although the frame can also be placed on a substrate such as silicon, it is more practical to place the frame on the cover glass from a cost perspective.

[0008] When manufacturing a glass dome with an outer frame, the simplest method is to make the glass dome and the frame separately and then bond them together using resin-based components. However, bonding with resin-based components, which are organic materials, cannot achieve an airtight seal.

[0009] One method for achieving an airtight seal is to form the frame portion by directly wet etching the glass. However, besides failing to achieve perpendicularity between the flat portion and the frame portion, it is also difficult to manufacture a deep frame. Therefore, in order to achieve an airtight seal while maintaining this perpendicularity, direct bonding methods such as diffusion bonding or room temperature bonding can be used to bond the flat glass to the frame glass. On the other hand, direct bonding is very expensive.

[0010] In contrast, from various perspectives, technologies for setting an outer frame on a glass substrate have been researched and proposed.

[0011] For example, the synthetic quartz glass cavity disclosed in Patent Document 1 is formed by sandblasting to create multiple through holes in a raw synthetic quartz glass substrate. This raw synthetic quartz glass substrate is then bonded to another raw synthetic quartz glass substrate at 1000–1200°C, thereby obtaining the aforementioned synthetic quartz glass cavity.

[0012] Patent Document 2 discloses a framed antireflective glass that uses borosilicate glass as a flat component and a silicon substrate as a frame component. Through-holes are formed by reactive ion etching of the silicon substrate, the frame component is overlapped onto the flat component, and the two are joined by anodic bonding, thereby obtaining the aforementioned framed antireflective glass.

[0013] Patent document 3 discloses a glass sealing material that joins a glass plate and a glass sheet by heating and pressing them together using a base mold frame and an opposing mold frame.

[0014] Patent document 4 discloses an airtight container in which a bonding material formed by screen printing a paste, such as glass material with a softening point lower than that of the glass substrate, onto a glass substrate is used as a frame component.

[0015] Patent document 5 discloses a method for obtaining a glass substrate with partition walls by filling a mold frame with a paste consisting of a heat-reducing curable resin composition containing glass powder, or by pressing a sheet consisting of a heat-reducing curable resin composition containing glass powder to a mold frame and heating it.

[0016] Existing technical documents

[0017] Patent documents

[0018] Patent Document 1: Japanese Patent Application Publication No. 2020-21937

[0019] Patent Document 2: Japanese Patent No. 5646981

[0020] Patent Document 3: Japanese Patent Application Publication No. 2013-222522

[0021] Patent Document 4: Japanese Patent Application Publication No. 2011-233479

[0022] Patent Document 5: Japanese Patent Application Publication No. 2005-243454 Summary of the Invention

[0023] However, if heat is applied at a temperature exceeding the softening point of the glass material used, as described in Patent Documents 1 and 3, the surface of the glass will be damaged, raising concerns about reliability. If the coefficients of thermal expansion of the flat component and the frame component differ, as described in Patent Document 2, cracks may occur in the glass used as the flat component. Furthermore, the cost of anodizing is high. If the paste is applied as described in Patent Document 4, there are concerns about reduced sealing performance due to uneven coating and film thickness. In the method described in Patent Document 5, the height of the partition wall serving as the outer frame is limited to approximately 150 μm.

[0024] Therefore, the purpose of this invention is to provide a framed cover glass that achieves a certain height while maintaining high verticality, and also ensures a tight seal with the cover glass, reducing damage and cracks to the flat glass surface, and is capable of hermetically sealing the semiconductor light-emitting device and the semiconductor light-receiving device.

[0025] The inventors conducted in-depth research and found that by using a specific glass ceramic for the outer frame, the above-mentioned problems could be solved, thus completing the present invention.

[0026] That is, the present invention and one of its embodiments relate to the following [1] to

[10] .

[0027] [1] A framed glass cover, wherein a framed glass cover has an outer frame disposed on one main surface of a flat glass, the outer frame being made of a glass ceramic in which filler components are dispersed in a glass matrix, the glass matrix comprising at least one of bismuth oxide and boron oxide, the coefficient of thermal expansion of the glass ceramic being 15 × 10⁻⁶. －7 The temperature is above / ℃ and below the coefficient of thermal expansion of the aforementioned flat glass. The filler composition includes at least one negative thermal expansion filler. In the aforementioned glass ceramic, the total volume fraction of the aforementioned negative thermal expansion filler is 40 to 65%, and the total volume fraction of the aforementioned filler composition is 40 to 65%. The softening point of the glass composition in the aforementioned glass matrix is ​​lower than the glass transition point of the aforementioned flat glass. The aforementioned flat glass is directly bonded to the aforementioned outer frame.

[0028] [2] According to the above [1], the outer frame of the cover glass is wherein at least one of the negative thermal expansion filler is an inorganic powder containing at least one of zirconium phosphate and β-lithium nepheline.

[0029] [3] According to the above [1] or [2], the glass cover with an outer frame has a light diffusion portion on the main surface of the same side as the side on which the outer frame is provided, and the light diffusion portion is formed by direct processing of the glass cover.

[0030] [4] According to the above [3], the glass cover with an outer frame is formed further inside than the area directly joined to the outer frame.

[0031] [5] A glass cover with an outer frame according to any one of [1] to [4] above, wherein the height of the outer frame is 350 μm to 4 mm.

[0032] [6] A framed glass according to any one of [1] to [5] above, wherein an anti-reflective film is provided on at least one main surface of the flat glass.

[0033] [7] A framed glass cover according to any one of [1] to [6] above, wherein a sealing material layer is provided on the surface of the outer frame facing the face that is directly joined to the flat glass, the sealing material layer being composed of a metal film or glass frit.

[0034] [8] A framed glass according to any one of [1] to [7] above, wherein the flat glass has a conductive film on the main surface of the same side as the side on which the frame is provided, and a metal conductor is provided inside the frame and is provided perpendicular to the flat glass, wherein the conductive film is in communication with the metal conductor.

[0035] [9] A semiconductor light-emitting device, wherein the light-emitting element disposed on the substrate is hermetically sealed by a glass cover with an outer frame as described in any one of [1] to [8].

[0036]

[10] A semiconductor light-receiving device, wherein the light-receiving element disposed on the substrate is hermetically sealed by a glass cover with an outer frame as described in any one of [1] to [8].

[0037] The framed cover glass according to the present invention maintains high verticality even with a certain frame height, while also ensuring a tight seal with the cover glass and preventing damage to the cover glass caused by the energy of the light source (UV-LED, LD (laser diode), etc.) or the energy of the light received by the sensor. Furthermore, since there is no heat-induced damage or cracking on the surface of the flat glass, the reliability of the framed cover glass is extremely high. This reliability is considered not only in terms of airtightness but also from the perspectives of resistance to high temperature and humidity, thermal shock, reagent resistance, and verticality. Therefore, excellent semiconductor light-emitting devices and semiconductor light-receiving devices can be obtained. Attached Figure Description

[0038] Figure 1 This is a cross-sectional schematic diagram showing an example of a framed glass cover according to this embodiment.

[0039] Figure 2 This is a cross-sectional schematic diagram showing an example of a framed glass cover according to this embodiment.

[0040] Figure 3 This is a cross-sectional schematic diagram showing an example of a framed glass cover according to this embodiment.

[0041] Figure 4 This is a cross-sectional schematic diagram showing an example of a framed glass cover according to this embodiment. Figure 4 (a) is an example of a flat glass plate with anti-reflective coatings on both main surfaces. Figure 4 (b) is an example of a flat glass with a light-diffusing section on one main surface and an anti-reflective film on two main surfaces. Detailed Implementation

[0042] The present invention will now be described in detail, but the present invention is not limited to the following embodiments and can be implemented by any modifications without departing from the spirit of the present invention.

[0043] In this specification, the "~" sign indicating a numerical range is used to encompass the values ​​listed before and after it as the lower and upper limits.

[0044] The “coefficient of thermal expansion” in this specification refers to the value determined by the average of the proportion of elongation per 1°C when heated in the range of 50 to 350°C.

[0045] The glass composition content in the glass matrix mentioned in this specification refers to the content of the composition obtained after removing filler components from the glass ceramic, and is expressed as a mass % value based on oxides. Furthermore, "mass %" and "weight %" have the same meaning.

[0046] <Framed glass cover>

[0047] like Figure 1 As shown, in this embodiment, the framed glass 10 has an outer frame 2 on one main surface of the flat glass 1. The outer frame 2 is formed along the outer edge of the flat glass 1.

[0048] The outer frame 2 is made of glass ceramic in which filler components are dispersed in a glass matrix, and the flat glass 1 is directly bonded to the glass ceramic that serves as the outer frame 2.

[0049] The glass matrix contains at least one of bismuth oxide and boron oxide. The glass softening point of the glass matrix is ​​lower than the glass transition point of the planar glass 1.

[0050] The coefficient of thermal expansion of glass ceramics is 15×10⁻⁶. －7 The thermal expansion coefficient is within the range of / ℃ above and below that of flat glass 1.

[0051] The filler composition constituting the glass-ceramic includes at least one negative thermal expansion filler, and the total volume fraction of the negative thermal expansion filler in the glass-ceramic is 40-65%. Additionally, the total volume fraction of the filler composition in the glass-ceramic is 40-65%.

[0052] The flat glass 1 is directly bonded to the outer frame 2. Direct bonding refers to the bonding of the flat glass 1 and the outer frame 2 without the use of an adhesive layer of organic materials such as resin layers other than the flat glass 1 and the outer frame 2. It should be noted that when a conductive film 4, which is an inorganic material described later, is formed on the main surface of the flat glass 1, the flat glass 1 and the outer frame 2 are bonded through the conductive film 4. In this case, the conductive film 4 is treated as a structure made of an inorganic material integral with the flat glass 1, and this is one method of directly bonding the flat glass 1 and the outer frame 2.

[0053] The direct bonding of the flat glass 1 to the outer frame 2 does not require the application of voltage such as anodic bonding; the bonding can be achieved simply by overlapping the flat glass 1 and the outer frame 2 and heating them.

[0054] Because it is achieved through direct bonding without the need for organic materials such as resin layers, it exhibits excellent durability. Furthermore, the manufacturing process is simplified as it eliminates the need for an adhesive layer.

[0055] It should be noted that whether or not a direct joint is used can be determined by whether there is the aforementioned adhesive layer between the flat glass 1 and the outer frame 2.

[0056] For the glass-ceramic used as the outer frame 2, the glass softening point Ts of the glass matrix constituting the glass-ceramic is lower than the glass transition point Tg of the flat glass 1. Therefore, direct bonding can be achieved without the need for high temperatures that would damage the surface of the flat glass 1.

[0057] From the viewpoint of preventing damage to the surface of the flat glass 1, the difference between the glass transition point Tg of the flat glass 1 and the glass softening point Ts of the glass matrix is ​​preferably 50°C or more, more preferably 65°C or more, and even more preferably 75°C or more.

[0058] The glass transition point Tg of the flat glass 1 is preferably within the range described above, differing from the glass softening point Ts of the glass matrix. However, from the viewpoints of suppressing the increase of carbon residue during calcination and hindering insulation, and from the viewpoints of heat resistance during substrate sealing, it is specifically preferred to be 500°C or higher, more preferably 525°C or higher, and even more preferably 545°C or higher, with higher values ​​being more preferred. It should be noted that the glass transition point Tg of the flat glass 1 is the temperature of the first inflection point of the DTA chart obtained by differential calorimetry (DTA).

[0059] From the viewpoint of preventing damage to the surface of the flat glass, the glass softening point Ts of the flat glass 1 is preferably 700°C or higher, more preferably 750°C or higher, and even more preferably 800°C or higher, with higher being more preferred. It should be noted that the glass softening point Ts of the flat glass 1 is the temperature of the fourth inflection point on the DTA diagram.

[0060] The glass softening point Ts of the glass matrix is ​​preferably within the range described above, differing from the glass transition point Tg of the planar glass 1. Specifically, it is preferably below 700°C, more preferably below 650°C, and even more preferably below 600°C. Furthermore, from the viewpoint of suppressing the increase of carbon residue during calcination and hindering insulation, and from the viewpoint of heat resistance during substrate sealing, the glass softening point Ts of the glass ceramic is preferably above 450°C, more preferably above 460°C, and even more preferably above 470°C. It should be noted that the glass softening point Ts of the glass matrix is ​​the temperature of the fourth inflection point on the DTA diagram of the glass monomer.

[0061] Considering the coefficient of thermal expansion of the substrate approximately equal to that of the framed glass cover 10, the coefficient of thermal expansion of glass-ceramic is approximately 15 × 10⁻⁶. －7 The thermal expansion coefficient is within the range of / ℃ above and below that of flat glass 1.

[0062] The preferred coefficient of thermal expansion for glass ceramics is 16 × 10⁻⁶. －7 / ℃ or higher, more preferably 17×10 －7 / ℃ or higher, and also varies depending on the coefficient of thermal expansion of the flat glass 1, for example, preferably 75 × 10 －7 Below / ℃, more preferably 70×10 －7 Below / ℃, further preferably 65×10 －7 / ℃ below.

[0063] Furthermore, from the viewpoint of preventing cracks from forming in the flat glass 1 when directly bonding it to the glass-ceramic, the difference (the thermal expansion coefficient of the flat glass - the thermal expansion coefficient of the glass-ceramic) should be 0 / ℃ or higher, and preferably 4 × 10⁻⁶. －7 / ℃ or higher, more preferably 6×10 －7 / ℃ or higher, and preferably 24×10 －7 Below / ℃, more preferably 22×10 －7 / ℃ below.

[0064] The coefficient of thermal expansion of the flat glass 1 is not particularly limited as long as it is greater than or equal to that of glass-ceramic. However, from the viewpoint of approximating the coefficient of thermal expansion of the substrate on which the framed cover glass 10 is mounted, a coefficient of thermal expansion of 20 × 10⁻⁶ is preferred. －7 / ℃ or higher, more preferably 23×10 －7 / ℃ or higher, and preferably 99×10 －7 Below / ℃, more preferably 92×10 －7 / ℃ below.

[0065] The glass matrix constituting the glass ceramic contains at least one of bismuth oxide and boron oxide in its glass composition. As a result, the glass softening point Ts is reduced.

[0066] As long as the glass softening point Ts of the glass matrix is ​​lower than the glass transition point Tg of the flat glass 1, the content of bismuth oxide is not particularly limited. For example, it is preferably 25% by mass or more, and more preferably 30% by mass or more. On the other hand, from the viewpoint of suppressing the reduction of the weather resistance of the flat glass 1, the content of bismuth oxide is preferably 95% by mass or less, and more preferably 90% by mass or less.

[0067] As long as the glass softening point Ts of the glass matrix is ​​lower than the glass transition point Tg of the flat glass 1, the boron oxide content is not particularly limited. For example, it is preferably 5% by mass or more, more preferably 10% by mass or more. On the other hand, from the viewpoint of suppressing the reduction of the weather resistance of the flat glass 1, the boron oxide content is preferably 50% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0068] When both bismuth oxide and boron oxide are present, from the viewpoint of suppressing the decrease in the weather resistance of the flat glass 1, it is preferable that the content of bismuth oxide is greater than the content of boron oxide.

[0069] As mentioned above, as a glass matrix containing at least one of bismuth oxide and boron oxide, glasses generally referred to as bismuth oxide glasses and borosilicate glasses are commonly referred to as such.

[0070] As a bismuth oxide-based glass, in addition to Bi2O3, it can also contain B2O3, CeO2, SiO2, RO, R'2O, R”2O3, R”'O2, etc.

[0071] It should be noted that R refers to at least one selected from Zn, Ba, Sr, Mg, Ca, Fe, Mn, Cr, Sn, and Cu. R' refers to at least one selected from Li, Na, K, Cs, and Cu. R” refers to at least one selected from Al, Fe, and La. R”' refers to at least one selected from Zr, Ti, and Sn.

[0072] Furthermore, when R is Al, Al2O3 is clearly distinguished from alumina, which is a filler component constituting glass ceramics. That is, the content of Al2O3 as a component of glass is excluded from the content of inorganic powder containing alumina as a filler component.

[0073] As a bismuth oxide-based glass, more specifically, for example, a glass containing 30 to 90% by mass of Bi₂O₃ and 5 to 20% by mass of B₂O₃ is preferably used. This glass may further contain 0 to 10% by mass of CeO₂, 0 to 20% by mass of SiO₂, 0 to 55% by mass of RO, 0 to 10% by mass of R'₂O, 0 to 20% by mass of R'₂O₃, and 0 to 30% by mass of R''O₂.

[0074] As a borosilicate glass, in addition to SiO2 and B2O3, it may also contain CeO2, RO, R'2O, R”2O3, R”'O2, etc., and preferably contains ZnO, K2O, and Na2O.

[0075] More specifically, for example, glass containing 23-35% by mass of SiO2, 40-55% by mass of B2O3, 10-20% by mass of ZnO, and a total of 3-15% by mass of K2O and Na2O may be preferred.

[0076] The following describes the components other than bismuth oxide (Bi2O3) and boron oxide (B2O3).

[0077] SiO2 is a component of glass. On the other hand, if added in excess, there is a concern that the glass softening point (Ts) will become too high.

[0078] CeO2 is a component that stabilizes the color of the glass powder obtained after glass raw materials are melted and vitrified. When bismuth oxide is present, it is preferable to include it as well. On the other hand, if an excessive amount is added, there is a concern that it may easily crystallize and make it difficult to obtain stable glass powder.

[0079] RO, which includes CaO, indicates a component that is effective in stabilizing glass and inhibiting crystallization. On the other hand, if added in excess, there is a concern that the glass softening point (Ts) may become too high.

[0080] R'2O, which includes K2O and Na2O, represents a component that lowers the glass softening point (Ts). The smaller the atomic number of the element, the greater the effect. However, the higher the content of elements with smaller atomic numbers, the greater the concern that the glass's insulation properties may decrease, thus compromising reliability.

[0081] The component represented by R"2O3, which contains Al2O3, is effective in stabilizing glass, thereby inhibiting crystallization and improving the chemical durability of the glass. On the other hand, if added in excess, there is a concern that the glass softening point Ts may become too high.

[0082] R”'O2 indicates the component that supplies oxygen during bonding. On the other hand, if added in excess, there is a concern that foaming may occur during bonding.

[0083] The filler components in glass-ceramics are dispersed within a glass matrix. The filler components include at least one negative thermal expansion filler.

[0084] Negative thermal expansion packing refers to packing with a negative coefficient of thermal expansion, i.e., less than 0 / ℃.

[0085] By using negative thermal expansion filler, even for substrates with low coefficients of thermal expansion, the coefficient of thermal expansion of the glass-ceramic can be appropriately controlled when mounting a framed cover glass 10. Furthermore, by using a specified amount of negative thermal expansion filler, both the perpendicularity of the frame 2 to the flat glass 1 and good sealing can be achieved. If only low thermal expansion filler is used instead of negative thermal expansion filler, the controllability of the aforementioned coefficient of thermal expansion decreases, making it difficult to achieve both perpendicularity and good sealing.

[0086] As a specific example of negative thermal expansion packing, a thermal expansion coefficient of -20 × 10⁻⁶ can be cited. －7 Zirconium phosphate at / ℃ has a coefficient of thermal expansion of -50×10⁻⁶. －7 β-Lene-nepheline (Li₂O·Al₂O₃·2SiO₂) at / ℃ has a thermal expansion coefficient of -7×10⁻⁷. －7 Zirconium tungstate (ZrW2O8) at / ℃, etc. Among them, from the viewpoint of ease of material acquisition, it is preferred that at least one of the negative thermal expansion fillers is an inorganic powder containing at least one of zirconium phosphate and β-lithium nepheline.

[0087] From the viewpoint that the glass-ceramic provides strength as an outer frame 2, possesses perpendicularity to the flat glass 1, and prevents cracking of the flat glass 1, the total volume fraction of the negative thermal expansion filler in the glass-ceramic is 40% or more, preferably 43% or more, and more preferably 45% or more. Furthermore, from the viewpoint of achieving high sealing performance by directly bonding the glass-ceramic, which serves as the outer frame 2, to the flat glass 1, and from the viewpoint of preventing cracking of the flat glass 1, the total volume fraction of the negative thermal expansion filler is 65% or less, preferably 63% or less, and more preferably 61% or less.

[0088] When inorganic powder containing zirconium phosphate is used as a negative thermal expansion filler, the volume fraction of zirconium phosphate in the glass ceramic is 40% or more, preferably 43% or more, more preferably 45% or more, and further preferably 65% ​​or less, preferably 63% or less, more preferably 61% or less. When negative thermal expansion fillers other than zirconium phosphate are included, it is preferable that their total content be within the above range.

[0089] When inorganic powder containing only β-nepheline is used as a negative thermal expansion filler, the volume fraction of β-nepheline in the glass ceramic is 40% or more, preferably 43% or more, more preferably 45% or more, and further preferably 65% ​​or less, preferably 63% or less, more preferably 61% or less. When negative thermal expansion fillers other than β-nepheline are included, it is preferable that their total content be within the above range.

[0090] The packing composition may also include other packings besides the negative thermal expansion packings mentioned above. When other packings are included, it is preferable that the thermal expansion coefficient of the packing, known as a low thermal expansion packing, is 0 × 10⁻⁶. －7 / ℃~40×10 －7 The packing material is ℃.

[0091] Examples of fillers with low thermal expansion include zirconium oxide, silica, and mixtures thereof. Examples of mixtures include cordierite (2MgO·2Al2O3·5SiO2), a mixture of magnesium oxide, aluminum oxide, and silica.

[0092] From the viewpoint of preventing cracks in the flat glass 1, the total volume fraction of the filler components in the glass ceramic is 40% or more, preferably 43% or more, and more preferably 45% or more. Furthermore, from the viewpoint of obtaining good adhesion with the flat glass 1, the above-mentioned volume fraction is 65% or less, preferably 63% or less, and more preferably 61% or less. However, the above content can vary depending on the specific gravity of the filler components, etc. It should be noted that the total filler components, when including other fillers besides the negative thermal expansion filler, refer to the total of the negative thermal expansion filler and the other fillers.

[0093] Furthermore, from the viewpoint of appropriately obtaining the effect based on the negative thermal expansion filler, the total proportion of the negative thermal expansion filler in the overall filler composition is preferably 43% or more by volume fraction, more preferably 45% or more, and may also be 100%, i.e., only negative thermal expansion filler.

[0094] The filler is composed of inorganic powder, and there are no particular limitations on its shape, such as spherical, flat, scaly, or fibrous.

[0095] There are no particular limitations on the size of inorganic powders, for example, 50% of the particle size (D 50 The particle size is preferably 0.5 μm or more, more preferably 2 μm or more, and further preferably 10 μm or less, more preferably 9 μm or less. The 50% particle size is a value measured using a laser diffraction / scattering particle size distribution measuring device.

[0096] There are no particular limitations on the flat glass as long as its coefficient of thermal expansion and glass transition point Tg satisfy the above-mentioned relationship with the coefficient of thermal expansion of the glass ceramic and the glass softening point Ts of the glass matrix.

[0097] For example, a flat glass is preferably transparent from the visible region to the near-infrared region.

[0098] Specifically, flat glass can be made of soda-lime glass, borosilicate glass, aluminosilicate glass, silica glass, etc. Borosilicate glass is preferred due to its ease of processing. Silica glass is preferred due to its durability and transparency.

[0099] In this embodiment, the framed glass 10 can have other configurations besides the flat glass 1 and the frame 2. For example, other configurations could include... Figure 2 As shown, examples include the light-diffusing section represented by symbol 1c and the sealing material layer represented by symbol 3. Additionally, as... Figure 3 As shown, examples include the conductive film represented by symbol 4 and the metallic conductor represented by symbol 5. Furthermore, as... Figure 4 As shown in (a) and (b), an example of an anti-reflective film represented by symbol 6 can be cited.

[0100] The following sections will explain each component in turn.

[0101] The flat glass 1 may have a light-diffusing portion on at least one main surface. When the main surface directly joined to the outer frame 2 is designated as the first main surface 1a, a light-diffusing portion 1c may be provided on the first main surface 1a. The light-diffusing portion 1c is formed by directly processing the first main surface of the flat glass 1. It should be noted that a light-diffusing layer may also be provided separately without the directly processed light-diffusing portion. In this case, from the viewpoint of airtightness, it is preferable that the light-diffusing layer is made of an inorganic material.

[0102] The light diffusion section 1c formed by directly processing the flat glass 1 is preferred from the viewpoint of reducing losses caused by interface reflection and preventing interlayer delamination compared to the light diffusion layer formed on the main surface of the flat glass 1.

[0103] From the viewpoint of ensuring a tight fit between the flat glass 1 and the outer frame 2, the light-diffusing portion 1c is preferably formed on the first main surface 1a of the flat glass 1 further inward than the area directly bonded to the outer frame 2. Furthermore, when performing such direct processing, the flat glass can appropriately use, for example, AN100 (trade name), M100 (trade name), M130 (trade name) manufactured by AGC, TEMPAX (trade name), D263 (registered trademark) manufactured by Schott AG, but is not limited to these.

[0104] The light diffusion section 1c preferably has multiple lenses, and more preferably the boundaries of adjacent lenses are sharp. Even more preferably, it is arranged without gaps on the first main surface 1a of the flat glass 1, at least an effective area.

[0105] The thickness of the flat glass 1 is not particularly limited, but from the viewpoint of durability, it is preferably 300 μm or more, more preferably 400 μm or more, and even more preferably 500 μm or more. On the other hand, from the viewpoint of transmittance and weight, the thickness of the flat glass 1 is preferably 1.5 mm or less, more preferably 1.2 mm or less, and even more preferably 1.1 mm or less.

[0106] From the viewpoint of preventing damage to the cover glass from light energy from the light source, the height of the outer frame 2 made of glass-ceramic is preferably 350 μm or more, more preferably 400 μm or more, and even more preferably 500 μm or more. On the other hand, from the perspective of the requirement for a low device height, the height of the outer frame is preferably 4 mm or less, more preferably 3 mm or less, and even more preferably 2 mm or less.

[0107] Considering the need to adjust the height by changing the number of layers, or to form a tall frame as required, it is preferable that the outer frame 2 is a calcined body of stacked green sheets. Details of the green sheets will be described later. Green sheets refer to sheets obtained by dispersing powder, such as a precursor of glass-ceramic, in a binder and then casting it.

[0108] From the viewpoint of airtight sealing when bonding the framed glass 10 to the substrate having light-emitting elements or light-receiving elements, the frame 2 preferably has a sealing material layer 3 on the surface of the face facing directly bonded to the flat glass 1.

[0109] The sealing layer 3 can be a layer made of metal film or a layer made of glass.

[0110] When the sealing material layer 3 is made of a metal film, the substrate and the cover glass 10 with an outer frame can be airtightly sealed by bonding with metal solder.

[0111] From the viewpoint of adhesion when using metal solder, the metal film preferably has a metal coating (not shown) of one or more metals selected from Au, Ag, Cu and Au-Sn alloys on its outermost surface, and more preferably an Au coating. As the substrate for the above coating, a Ni coating, a Ti coating, or other coating (not shown) may be provided.

[0112] It should be noted that when the outer frame 2 has the metal conductor 5 described later, it is preferable that the metal film has a metal coating using the same metal as the metal conductor 5.

[0113] When the sealing material layer 3 is made of glass, the substrate can be hermetically sealed to the cover glass 10 with an outer frame by heat-based bonding.

[0114] The sealing glass is made of low-melting-point glass, and conventionally known glass can be used. For example, tin-phosphate glass, bismuth glass, vanadium glass, lead glass, zinc borate glass, and other low-melting-point glasses can be appropriately used. Among these, considering reliability such as adhesion, bonding reliability, and airtightness, as well as the impact on the environment and human health, low-melting-point glasses made of tin-phosphate glass or bismuth glass are preferred.

[0115] The glass frit can also contain inorganic fillers such as electromagnetic wave absorbers and low thermal expansion fillers.

[0116] From the perspective of the purpose of the framed glass 10 and the efficient use of space, the frame 2 is preferably arranged perpendicular to the flat glass 1. The flat glass 1 being perpendicular to the frame 2 means that the angle formed by the outer surfaces of the flat glass 1 and the frame 2 is perpendicular. It should be noted that the perpendicularity does not need to be strictly 90°; approximately perpendicularity of 90° ± 5° is sufficient.

[0117] Furthermore, the framed glass 10 preferably includes a system capable of detecting breakage of the flat glass 1, depending on its intended use. As an example of this system, the flat glass 1 preferably has a conductive film 4 on its main surface on the same side as the side where the frame 2 is located. Additionally, it is preferable to have a metal conductor 5 inside the frame 2, penetrating the frame 2 and disposed perpendicular to the flat glass 1, and the conductive film 4 is in communication with the metal conductor 5.

[0118] An outer frame 2 is directly attached to the main surface of the flat glass 1, but as Figure 3As shown, when the conductive film 4 is also formed on all areas of the main surface of the flat glass 1, i.e., the area where it is joined with the outer frame, the flat glass 1 and the outer frame 2 will be joined through the conductive film 4. In this case, the conductive film 4, which is made of inorganic material, is treated as an integral structure with the flat glass 1, and is set as a way to directly join the flat glass 1 and the outer frame 2.

[0119] The conductive film 4 can be made of conventionally known inorganic materials. From the viewpoint of light transmittance, a transparent conductive film is preferred, such as ITO (Indium Tin Oxide) film, SnO2 film, ZnO film, etc. Among them, ITO film is preferred from the perspective of durability and resistance.

[0120] The thickness of the conductive film 4 is not particularly limited, but to ensure stable conductivity, it is preferably 0.05 μm or more, more preferably 0.1 μm or more, and even more preferably 0.2 μm or more. Furthermore, to maintain permeability, the thickness of the conductive film 4 is preferably 1 μm or less, more preferably 0.8 μm or less, and even more preferably 0.7 μm or less.

[0121] The conductive film 4 only needs to be formed on at least a portion of the main surface of the flat glass 1. For the purpose of detecting the breakage of the flat glass 1, it is preferable to form it at least in the effective area, that is, the area irradiated by light from the light source, and more preferably in all areas of the main surface of the flat glass 1.

[0122] In addition, when films and layers other than the conductive film 4 are formed on the main surface of the flat glass 1, it is preferable to form the conductive film 4 on the outermost surface of the side where the substrate with the light-emitting element or the light-receiving element is located, which is further outward than these other films and layers.

[0123] The metal conductor 5, sometimes referred to as a via, is a conductor that electrically connects the upper and lower layer wiring. In this embodiment, the metal conductor 5 is connected to the conductive film 4 in order to connect the conductive film 4 to the detector that detects the breakage of the flat glass 1.

[0124] The metal conductor 5 can be applied using conventionally known methods. For example, before or after firing the glass-ceramic constituting the outer frame 2, a hole is provided penetrating the interior of the outer frame 2, and the metal conductor 5 is laid therein.

[0125] The metal conductor 5 can be any metal that is conductive. From the perspective of ease of manufacture, it is preferable to select one or more metals from Ag, Au, and Cu, with Ag being more preferred. Ease of manufacture means that the glass-ceramic that will become the outer frame 2 can be sintered together during the calcination and sintering process.

[0126] The shape of the metal conductor 5 is not particularly limited, but a metal wire is preferred from the viewpoint of easy penetration into the interior of the outer frame 2. From the viewpoint of preventing the metal conductor 5 from becoming uneven and cracking in the glass-ceramic serving as the outer frame 2 during firing, the diameter of the through-hole, which is the diameter of the metal wire, is more preferably 0.2 mm or less, and even more preferably 0.1 mm or less. The lower limit of the through-hole diameter is not particularly limited, but from the viewpoint of preventing the metal conductor 5 from breaking, it is preferably 0.05 mm or more.

[0127] In addition, the framed glass 10 of this embodiment may further have an anti-reflective film 6 or the like on at least one main surface of the flat glass 1.

[0128] The anti-reflective film 6 is preferably formed on at least one main surface of the flat glass 1. That is, the anti-reflective film 6 can be formed on a first main surface 1a on one side where the substrate with the light-emitting element or the light-receiving element is located, or it can be formed on a second main surface 1b on the other side. Additionally, as... Figure 4 As shown in (a), it can also be formed on two main surfaces.

[0129] When the framed glass cover 10 has a light-diffusing section 1c, such as Figure 4 As shown in (b), it is preferable to form an anti-reflective film 6 on the surface of the light diffusion portion 1c, that is, on the outer side of the light diffusion portion 1c.

[0130] The antireflective film 6 is not particularly limited as long as it has at least the antireflective function of reducing the reflectivity of light of the designed wavelength. From the viewpoint of preventing it from disappearing when the outer frame 2 is calcined, the antireflective film 6 is preferably a film formed of inorganic materials, such as a single-layer thin film, a dielectric multilayer film with two or more dielectric layers of different refractive indices such as SiO2 and Ta2O5, etc.

[0131] The flat glass 1 may, in addition to the above-described components, also have layers, films, etc. that have a certain function, without impairing the effect of the present invention.

[0132] It should be noted that when the flat glass 1 has films made of inorganic materials such as an anti-reflective film 6 and a conductive film 4, and these films are formed in the bonding area with the outer frame 2, the flat glass 1 and the outer frame 2 will be bonded through the aforementioned films. In this case, it is also determined that the film and the flat glass 1 are integrally formed, and the flat glass 1 and the outer frame 2 are directly bonded.

[0133] The framed glass 10 can be deformed in any way without compromising the effects of the present invention. For example, a portion of the frame 2 can be cut, or the corners can be chamfered to make the metal conductor 5 removable, thus forming a straight line through the flat glass 1 and the frame 2.

[0134] Even with a certain frame height, the framed cover glass 10 of this embodiment ensures verticality and a tight seal with the cover glass. Furthermore, it reduces damage and cracks to the flat glass surface. Therefore, the framed cover glass 10 of this embodiment is suitable for hermetically sealing the substrate of a semiconductor light-emitting device and the substrate of a semiconductor light-receiving device.

[0135] That is, this embodiment also relates to a semiconductor light-emitting device that uses the aforementioned framed glass cover 10 to hermetically seal a light-emitting element disposed on a substrate. Examples of light-emitting elements include light-emitting diodes (LEDs) and semiconductor lasers (LDs). Aluminum nitride substrates are preferred as the substrate in this case. Furthermore, examples of semiconductor light-emitting devices incorporating these light-emitting elements include backlights for mobile phones and LCD TVs, light-emitting parts in operation buttons of small information terminals, deep ultraviolet LEDs for automotive or decorative lighting, deep ultraviolet LEDs for sterilization applications, laser parts for 3D ranging sensors, and other light sources.

[0136] Furthermore, this embodiment also relates to a semiconductor light-receiving device that uses the aforementioned cover glass 10 with an outer frame to hermetically seal a light-receiving element disposed on a substrate. Examples of light-receiving elements include MEMS sensors. A silicon substrate is preferred as the substrate in this embodiment.

[0137] <Method for manufacturing a framed glass cover>

[0138] One embodiment of the manufacturing method of the cover glass 10 with an outer frame will be described.

[0139] There is no particular limitation on the manufacturing method of the glass ceramic that forms the outer frame 2 in the glass cover 10 with an outer frame. For example, it can be obtained by molding and sintering a mixture of glass powder, which serves as the glass matrix, and filler components, i.e., a precursor of the glass ceramic. Specifically, a method can be given by molding the aforementioned precursor into a sheet shape called a green sheet and then sintering it.

[0140] The following shows an example of a method for manufacturing raw slices.

[0141] First, the raw materials are combined and mixed in a manner that yields the desired glass composition. The resulting mixture is then melted, cooled, and pulverized to obtain glass powder. The pulverized glass powder is then calcined to form a glass matrix, thus determining the glass composition of the glass ceramic. Therefore, the glass powder of this embodiment contains at least one of bismuth oxide and boron oxide. Furthermore, the preferred method for the glass powder is the same as the preferred method for the glass matrix described above in the section on "Glass Cover with Frame".

[0142] The melting temperature of the raw material mixture is preferably 500-800°C, and the melting time is preferably 30-60 minutes.

[0143] Pulverization can be performed using either dry or wet methods. In the case of wet pulverization, water, ethanol, or similar solvents can be used.

[0144] Crushing can be achieved using mills such as roller mills, ball mills, and jet mills.

[0145] Regarding the size of glass powder, considering both preventing glass powder agglomeration and difficulty in handling, and preventing the excessive time required for powder formation, a particle size of 50% (D) is recommended. 50 The particle size is preferably 0.5 μm or more, more preferably 1 μm or more. Furthermore, from the viewpoint of preventing an increase in the glass softening point Ts and insufficient sintering, a particle size of 50% (D...) is preferred. 50 Preferably, the micrometer is 10 μm or less, and more preferably 9 μm or less.

[0146] From the viewpoint of obtaining good sinterability and preventing the reduction of reflectivity due to undissolved components remaining in the sintered body, the maximum particle size of the glass powder is preferably 20 μm or less, and more preferably 10 μm or less.

[0147] The particle size can be adjusted by crushing and then grading as needed.

[0148] Next, the glass powder is mixed with the filler components to obtain the glass-ceramic precursor.

[0149] The filler composition uses at least one negative thermal expansion filler. The negative thermal expansion filler can be the same as that described in the section on "Glass Cover with Frame," and preferably, it can also be the same. Furthermore, for other fillers that may be included, the same filler as described in the section on "Glass Cover with Frame," and preferably, it can also be the same.

[0150] The negative thermal expansion filler is mixed in such a way that its total volume fraction in the resulting glass-ceramic is 40% to 65%. Furthermore, when other fillers are included, they are mixed in such a way that the total volume fraction of the filler components is 40% to 65% in the resulting glass-ceramic.

[0151] Slurries or pastes are prepared by adding organic solvents, plasticizers, binders, dispersants, etc., as needed to the precursors of glass ceramics.

[0152] Organic solvents include, for example, alcohols, ketones, and aromatic hydrocarbons. More specifically, toluene, methyl ethyl ketone, methanol, 2-butanol, xylene, etc., can be used, either one or a mixture of two or more.

[0153] Plasticizers include adipic acid-based and phthalic acid-based plasticizers. More specifically, bis(2-ethylhexyl) adipate, dibutyl phthalate, dioctyl phthalate, and butyl benzyl phthalate can be used.

[0154] Adhesives can include thermally decomposable resins. More specifically, acrylic resins, polyvinyl butyral, etc., can be used.

[0155] Dispersants can include surfactant-type dispersants. More specifically, products such as DISPERBYK180 (trade name, manufactured by BYK-Chemie) can be used.

[0156] A sheet is obtained by casting the resulting slurry or paste; this sheet is called a green sheet. Specifically, for example, a green sheet can be obtained by coating a film with a slurry or paste and then drying it.

[0157] There is no particular limit to the thickness of the raw film; it can be adjusted according to the coating thickness, slurry concentration, etc.

[0158] Next, the method for forming the outer frame 2 from the green sheet obtained above, and the method for directly joining the outer frame 2 to the flat glass 1 will be described.

[0159] First, the green sheets are stacked in an appropriate number of layers according to the desired height of the outer frame 2. Then, the inner surface is punched using a punching machine to form the outer frame shape. At this time, if the cover glass 10 with the outer frame has a metal conductor 5, a through hole for the metal conductor 5 can also be formed at the same time. It should be noted that when forming the glass ceramic, a molded body obtained by molding the glass ceramic precursor using a mold or the like can be used instead of the green sheets described above, but from the perspective of making it easier for wiring to pass through each layer, the green sheets are preferred.

[0160] Green sheets can be fabricated individually according to the desired frame shape, or large green sheets can be fabricated and punched at multiple locations using a punching machine to create a frame for multiple interconnected multi-piece bonding substrates. The green sheets are then overlapped with flat glass and hot-pressed together. The overlapped body after hot pressing is then fired to obtain a multi-piece framed cover glass where the green sheets are glass-ceramic and connected. Individual framed cover glass 10s are obtained by dividing this connected multi-piece framed cover glass. Alternatively, the green sheet laminate can be pre-fired to form glass-ceramic, then overlapped with flat glass and fired again for direct bonding.

[0161] The shape of the outer frame 2 is determined by the shape of the green sheet. That is, the shape of the inner side of the outer frame 2 comes from the shape when the green sheet is punched. In addition, the shape of the outer side of the outer frame 2 comes from the outer shape of the green sheet. When the cover glass 10 with the outer frame is obtained by dividing the multi-sheet connecting substrate, the shape when dividing after calcination becomes the shape of the outer side of the outer frame 2.

[0162] Flat glass 1 can be manufactured using known methods, or commercially available products can be used.

[0163] For example, glass raw materials are prepared in a manner that yields glass of the desired composition and then heated to melt. The molten glass is then homogenized through bubbling, stirring, and the addition of a clarifying agent, and formed into a glass sheet of a specified thickness using a known forming method, followed by slow cooling. Alternatively, after homogenizing the molten glass, it can be formed into a block shape and then cut after slow cooling to create a flat sheet.

[0164] Examples of methods for forming flat glass include float glass, pressing glass, melting glass, and drawing glass. In particular, drawing glass is preferred from the viewpoint of controlling glass thickness.

[0165] When a conductive film 4 is formed on the main surface of the flat glass 1 and made to be conductive with the metal conductor 5, it is preferable to form the conductive film 4 before the flat glass 1 is overlapped onto the green sheet.

[0166] The conductive film 4 can be formed on the main surface of the flat glass 1 using conventional methods. For example, when the conductive film is an ITO film, it is preferably formed using a sputtering method.

[0167] Furthermore, when the light diffusion portion 1c and the anti-reflective film 6 are provided on the same main surface of the flat glass 1, the conductive film 4 is preferably formed on their outermost surface, that is, the side closest to the substrate.

[0168] When the light-diffusing portion 1c is directly processed on the main surface of the flat glass 1, or when the anti-reflective film 6 is formed, the processing or film formation can be performed before the flat glass 1 is stacked on the green sheet, or after the cover glass 10 with the outer frame is obtained. However, when the light-diffusing portion 1c is provided as described above, or when the conductive film 4 is provided, it is preferable to process the light-diffusing portion 1c or form the conductive film 4 before stacking the flat glass 1 on the green sheet.

[0169] The antireflective coating 6 can be formed using conventionally known methods. For example, it can be formed by sequentially stacking a high-refractive-index layer and a low-refractive-index layer on the main surface of the flat glass 1 using known film-forming methods such as sputtering or vapor deposition.

[0170] It should be noted that when the anti-reflective film 6 is formed on the main surface of the flat glass 1 opposite to the side that is directly joined to the outer frame 2, i.e., on the second main surface 1b, it can be formed after the cover glass 10 with the outer frame is obtained.

[0171] The direct hot-pressing bonding of the green sheet and the flat glass 1 is not particularly limited as long as the green sheet and the flat glass 1 are integrated.

[0172] The temperature during crimping is preferably 60–65°C. The pressure during crimping is preferably 12400–14000 Pa. The crimping time is preferably 5–10 minutes.

[0173] The unsintered glass cover with an outer frame is degreased as needed and then calcined to produce a glass ceramic with filler components dispersed in the glass matrix. This results in a glass cover 10 with an outer frame, formed by directly bonding the glass ceramic (as the outer frame 2) to the flat glass 1.

[0174] When the unsintered framed cover glass is a multi-piece connected substrate, a single framed cover glass 10 is obtained by cutting it between adjacent holes using a cutting machine or laser after calcination.

[0175] Degreasing can be carried out as needed, preferably at 350–450°C. The degreasing time is preferably 1–10 hours.

[0176] The calcination temperature is above the glass softening point Ts of the glass matrix in the glass-ceramic, and preferably below the glass transition point Tg of the flat glass 1. This prevents heat damage to the surface of the flat glass 1.

[0177] The specific calcination temperature varies depending on the glass composition of the glass ceramic. From the viewpoint of obtaining sufficient sinterability, it is preferably 500°C or higher, more preferably 520°C or higher, and even more preferably 550°C or higher. In addition, from the viewpoint of preventing the metal constituting the sealing layer 3, the metal conductor 5, etc., from melting, the calcination temperature is preferably 900°C or lower, more preferably 750°C or lower, and even more preferably 680°C or lower.

[0178] From the viewpoint of achieving sufficient sinterability, the calcination time is preferably 10 minutes or more, more preferably 15 minutes or more, and even more preferably 25 minutes or more. Furthermore, from the viewpoint of productivity, the calcination time is preferably 120 minutes or less, more preferably 90 minutes or less, and even more preferably 60 minutes or less.

[0179] In addition to the above, the green sheet can also be heat-pressed without overlapping with the flat glass 1. Instead, the green sheet can be calcined separately to form a glass ceramic, which is then directly bonded to the flat glass. In this case, the outer frame of the glass ceramic overlaps with the flat glass and is directly calcined within the aforementioned calcination temperature range.

[0180] From the perspective of adhesion, it is preferable to smooth the surface of the glass ceramic by grinding or other processes before firing, which involves directly bonding the glass ceramic to the flat glass. The surface roughness Ra of the glass ceramic is preferably 0.3 μm or less, more preferably 0.1 μm or less.

[0181] The sealing layer 3 is formed on one surface of the green sheet that forms the outer frame shape, as needed. The aforementioned one surface refers to the surface opposite to the side that is joined with the flat glass 1. Alternatively, the sealing layer 3 can be formed on one surface of the glass-ceramic outer frame 2 by firing, or it can be formed after obtaining the cover glass 10 with the outer frame formed by directly joining the flat glass 1 and the outer frame 2.

[0182] The sealing layer 3 is formed from a metal film or a glass frit, and can be formed using conventionally known methods. For example, when the sealing layer 3 is a metal film, it can be formed by screen printing a conductive paste made by adding a medium such as ethyl cellulose to metal powder and a solvent as needed. Alternatively, when the sealing layer 3 is a glass frit, it can be formed by coating a paste made by mixing a glass frit of low melting point glass with a medium obtained by dissolving a resin as a binder component in a solvent.

[0183] When forming a substrate coating on the surface of the metal film of the sealing material layer 3, between the outer frame and the metal film, these coatings can also be formed using conventionally known methods. For example, they can be formed using electrolytic plating or non-electrolytic plating.

[0184] When setting the metal conductor 5, it can be formed by filling pre-formed through holes with, for example, metal paste using screen printing. The metal conductor 5 can fill the through holes of a green sheet that forms an outer frame, or it can fill the through holes of a glass-ceramic outer frame that has been calcined.

[0185] In addition to screen printing, the sealing material layer 3 and the metal conductor 5 can also be formed by sputtering, vapor deposition, etc.

[0186] Example

[0187] The following examples illustrate the present invention in detail, but the present invention is not limited thereto.

[0188] Examples 1-2 to 1-4, 1-8, 1-9, 2 and 3 are examples, while examples 1-1, 1-5 to 1-7 and 1-10 to 1-14 are comparative examples.

[0189] Examples 1-1 to 1-14 illustrate the direct bonding of a flat glass plate and a glass ceramic by pressing a glass ceramic precursor into a powder on one of the main surfaces of the glass plate and then calcining it. Therefore, although the glass ceramic is not a framed glass cover, the verification of the adhesion between the flat glass and the glass ceramic, the perpendicularity of the frame, and the absence of cracks or other damage on the surface of the flat glass can be treated the same as when manufacturing a framed glass cover, and are thus treated as examples or comparative examples.

[0190] [Example 1-1~Example 1-14]

[0191] As a flat glass, a 50mm × 50mm glass plate (manufactured by AGC, AN100) with a thickness of 0.5mm and made of alkali-free borosilicate glass was prepared. The glass transition point is 710℃, and the coefficient of thermal expansion is 39 × 10⁻⁶. －7 / ℃.

[0192] Glass powder (manufactured by AGC, ASF-1109) was prepared as a precursor for glass ceramics. The 50% particle size of the glass powder was 2.8 μm, and the glass softening point of the resulting glass matrix was 545 °C after calcination.

[0193] For the aforementioned glass powder, the filler components listed in Table 1 were mixed at the volume fractions listed in Table 1 to prepare a powder as a precursor for glass ceramics. This precursor powder was then pressurized using a hydraulic press to produce cylindrical pressed powder bodies with a diameter of 17 mm and a height of 5 mm. By adjusting the weight of the powder used, regardless of differences in the specific gravity of the precursor powder, the volumes of the pressed powder bodies in Examples 1-1 to 1-14 were kept constant.

[0194] By placing the pressed powder obtained above on one main surface of a flat glass and calcining it at the following temperatures, a glass ceramic is obtained. The flat glass and the glass ceramic are then directly bonded together, thereby obtaining a glass plate with a glass ceramic that mimics a framed glass cover. The calcination temperatures are 600°C for Examples 1-1 to 1-4, 1-7, 1-11, and 1-12; 620°C for Examples 1-5, 1-8, and 1-9; and 640°C for Examples 1-6, 1-10, 1-13, and 1-14.

[0195] It should be noted that, as filler components, zirconium phosphate uses ULTEA (registered trademark) WH2 manufactured by Toa Synthetic Co., Ltd., β-nepheline uses FE-200 manufactured by Marus-Oil Joint Venture Co., Ltd., and cordierite uses SS-600 manufactured by Marus-Oil Joint Venture Co., Ltd.

[0196] [evaluate]

[0197] The obtained glass plates with glass ceramics were evaluated for the coefficient of thermal expansion of the glass ceramics, the tightness of the seal between the flat glass and the glass ceramics, the perpendicularity of the glass ceramics to the flat glass, and the presence or absence of cracks on the surface of the flat glass.

[0198] For the coefficient of thermal expansion of glass ceramics, the elongation per 1°C was measured using a TMA-50 instrument manufactured by SHIMADZU, within the heating range of 50–350°C, and the average value was taken as the coefficient of thermal expansion. The results are shown in Table 1.

[0199] To confirm the adhesion between the flat glass and the glass-ceramic, the bonding area between the flat glass and the glass-ceramic on the glass plate was observed under a microscope from the glass surface. An OLYMPUS MVX10 stereo microscope was used for observation.

[0200] The results are shown in Table 1 under “Fitness”, where “○” indicates the bonding between the flat glass and the glass-ceramic, and “×” indicates that the bonding was not observed.

[0201] The perpendicularity of the glass-ceramic to the flat glass was determined using an OLYMPUS stereomicroscope MVX10.

[0202] The results are shown in Table 1 under "Verticality," with "○" indicating high verticality of the glass-ceramic. Specifically, since glass-ceramic is formed by calcining cylindrical pressed powder, it also becomes cylindrical, similar in shape to the pressed powder. However, in reality, it is difficult to achieve a completely similar shape during calcination. Therefore, when the maximum length of the transverse direction of the cylindrical glass-ceramic cross-section, i.e., the direction corresponding to the diameter 2r of the circle of the upper and lower surfaces that form the cylinder, is defined as L1, and the transverse direction of the area where the glass-ceramic is joined to the flat glass, i.e., the diameter of the circle of the lower surface of the cylinder, is defined as L2, the case where the difference (L1-L2) is less than 1.0 mm is marked as "○".

[0203] In addition, in Table 1, “perpendicularity” marked with “×” means that the difference represented by (L1-L2) above exceeds 1.0 mm, which means that the glass ceramic loses its verticality and has a curvature in the horizontal direction.

[0204] Whether there are cracks on the surface of a flat glass can be determined by observing the surface of the flat glass using an OLYMPUS stereo microscope MVX10.

[0205] The results are shown in Table 1 under “Cracks”. “○” indicates that no cracks were observed on the surface of the flat glass, and “×” indicates that cracks were observed on the surface of the flat glass.

[0206] It should be noted that cracks on the surface of flat glass may occur when the flat glass and glass-ceramic are well bonded directly, i.e., when the seal is good. Therefore, cases where the seal between the flat glass and glass-ceramic is rated as "×" are not considered in the evaluation and are indicated by "-" in Table 1.

[0207] [Table 1]

[0208]

[0209] Furthermore, based on the results of Examples 1-1 to 1-5 and Examples 1-6 to 1-10, it is evident that increasing the volume fraction of filler components in the glass-ceramic improves its verticality relative to flat glass. This is believed to be because a certain amount of filler component is sufficient to maintain the shape of the glass-ceramic. On the other hand, it is evident that excessively increasing the volume fraction of filler components reduces the adhesion relative to flat glass. This is believed to be because a smaller volume fraction of the glass matrix reduces the meltability of the glass matrix during calcination.

[0210] Therefore, it is important to ensure that the total volume fraction of the negative thermal expansion filler in the glass ceramic is 40-65%, and that the total volume fraction of the filler components is 40-65%.

[0211] The absence of cracks on the surface of flat glass refers to a situation where the coefficients of thermal expansion are consistent, or close to the point where cracks will not occur. When the coefficient of thermal expansion of the glass-ceramic is significantly different from that of the flat glass, as shown in Examples 1-1, 1-6, 1-7, and 1-10, cracks will still appear on the surface of the flat glass even if the adhesion between the flat glass and the glass-ceramic is good. While methods such as adding negative thermal expansion fillers or low thermal expansion fillers to the glass matrix have been considered to reduce the coefficient of thermal expansion of the glass-ceramic, negative thermal expansion fillers are required. However, it is known that if low thermal expansion fillers, such as those in Examples 1-11 to 1-14, are used to reduce the coefficient of thermal expansion of the glass-ceramic, it is impossible to simultaneously maintain the adhesion between the flat glass and the glass-ceramic, as well as the perpendicularity of the glass-ceramic, making it difficult to maintain an airtight seal.

[0212] [Example 2]

[0213] A glass precursor powder was prepared by combining and mixing glass frit (AGC, ASF-1109) at 43% by volume and zirconium phosphate (Toa Synthetic Chemicals, ULTEA (registered trademark) WH2) at 57% by volume. A slurry was prepared by mixing 1 kg of the glass precursor with 0.35 kg of a solvent (toluene:methyl ethyl ketone: methanol:2-butanol = 3:3:1:1, by mass) as an organic solvent, 0.060 kg of bis(2-ethylhexyl) adipic acid ester as a plasticizer, 0.447 kg of acrylic resin as a binder, and 0.015 kg of a dispersant (BYK-Chemie, trade name: DISPERBYK180).

[0214] The slurry is coated onto a polyethylene terephthalate (PET) film using a doctor blade method and then dried to produce green sheets. Each green sheet has a thickness of 200 μm.

[0215] Six green sheets are stacked, and 4.0mm x 4.0mm quadrilateral holes in an 8×8 checkerboard pattern are punched out using a hole puncher, resulting in an unsintered panel consisting of 64 interconnected segments forming a multi-piece frame. This panel is then calcined at 600℃ to obtain a 1mm thick glass-ceramic with 3.4mm x 3.4mm quadrilateral holes in an 8×8 checkerboard pattern.

[0216] One surface of the glass-ceramic was ground to a surface roughness Ra of less than 0.1 μm. The glass-ceramic was then placed on the main surface of a flat glass (manufactured by AGC, AN100) with the side of the glass that underwent the above-processing process in contact with the flat glass. The glass-ceramic was then fired at 620°C, thereby achieving direct bonding. The glass-ceramic was then cut into individual pieces of 5 mm × 5 mm using a blade, resulting in 64 glass covers with outer frames.

[0217] [Example 3]

[0218] Before directly bonding the flat glass to the glass ceramic, a light diffusion section is formed. Otherwise, a cover glass with an outer frame is obtained in the same manner as in Example 2.

[0219] The light diffuser is formed by directly machining multiple lenses on the main surface of the side of the flat glass where the glass-ceramic is directly bonded. The light diffuser is a 2.5mm × 2.5mm quadrilateral and avoids the area where the flat glass and glass-ceramic are directly bonded. The light diffuser is formed on the inside of the outer frame.

[0220] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2020-213972 filed on December 23, 2020 and Japanese Patent Application No. 2021-198726 filed on December 7, 2021, the contents of which are incorporated herein by reference.

[0221] Symbol Explanation

[0222] 1. Flat glass

[0223] 1a First Main Face

[0224] 1b Second Main Face

[0225] 1c light diffusion section

[0226] 2 outer frame

[0227] 3 sealing layer

[0228] 4. Conductive film

[0229] 5. Metallic conductors

[0230] 6 Anti-reflective film

[0231] 10. Framed glass dome

Claims

1. A framed glass cover, wherein the framed glass cover has an outer frame provided on one main surface of a flat glass plate. The outer frame is made of glass ceramic with filler components dispersed in a glass matrix. The glass substrate comprises at least one of bismuth oxide and boron oxide. The coefficient of thermal expansion of the glass-ceramic is 15 × 10⁻⁶. －7 The temperature is above ℃ and the coefficient of thermal expansion of the flat glass is below that of the plate glass. The filler composition includes at least one negative thermal expansion filler. In the glass-ceramic, the total volume fraction of the negative thermal expansion filler is 40-65%, and the total volume fraction of the filler components is 40-65%. The softening point of the glass component in the glass matrix is ​​lower than the glass transition point of the flat glass. The flat glass is directly joined to the outer frame.

2. The framed glass cover according to claim 1, wherein, At least one of the negative thermal expansion fillers is an inorganic powder containing at least one of zirconium phosphate and β-lithium nepheline.

3. The framed glass cover according to claim 1, wherein, The flat glass has a light-diffusing portion on the main surface of the same side as the side where the outer frame is located. The light-diffusing section is formed by the direct processing of the flat glass.

4. The framed glass cover according to claim 2, wherein, The flat glass has a light-diffusing portion on the main surface of the same side as the side where the outer frame is located. The light-diffusing section is formed by the direct processing of the flat glass.

5. The framed glass cover according to claim 3, wherein, The light diffusion section is formed further inside than the area directly joined to the outer frame.

6. The framed glass cover according to claim 4, wherein, The light diffusion section is formed further inside than the area directly joined to the outer frame.

7. The framed glass cover according to any one of claims 1 to 6, wherein, The height of the outer frame is 350μm to 4mm.

8. The framed glass cover according to any one of claims 1 to 6, wherein, An anti-reflective film is provided on at least one main surface of the flat glass.

9. The framed glass cover according to any one of claims 1 to 6, wherein, A sealing layer is provided on the surface of the outer frame that faces the plane directly to which it is joined. The sealing material layer is composed of a metal film or glass frit.

10. The framed glass cover according to any one of claims 1 to 6, wherein, The flat glass has a conductive film on the main surface of the same side as the side where the outer frame is located. The outer frame contains a metal conductor that extends through the frame and is perpendicular to the flat glass. The conductive film is in contact with the metal conductor.

11. A semiconductor light-emitting device, wherein the light-emitting element disposed on a substrate is hermetically sealed by a cover glass with an outer frame as described in any one of claims 1 to 10.

12. A semiconductor light-receiving device, wherein a light-receiving element disposed on a substrate is hermetically sealed by a cover glass with an outer frame as described in any one of claims 1 to 10.

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