Lid member and package

Abstract

A glass lid member 4 comprises a panel-shaped frame 7, and a dome-shaped protrusion 8 that protrudes from the frame 7. The protrusion 8 includes an inner surface 8a and an outer surface 8b. The protrusion 8 includes a top portion 13 and a base portion 11 that is formed integrally with the frame 7. An anti-reflection film 10a is formed on the inner surface 8a of the protrusion 8. A value (Ta1 / Ta3), which is obtained by dividing the thickness Ta1 of the anti-reflection film 10a formed on the base portion 11 of the protrusion 8 by the thickness of the anti-reflection film 10a formed on the top portion 13 of the protrusion 8, is not less than 0.75 but less than 1.

Description

Lid member and package

[0001] The present invention relates to a lid for a package and to a package having a lid.

[0002] For example, Patent Document 1 discloses a package including a base (substrate) on which a light-emitting element (LED element) is mounted, a dome-shaped lid member (light-transmitting cover) fixed to the base so as to cover the light-emitting element, and an adhesive material that joins the base and the lid member. In this package, the lid member is configured in a dome shape, thereby ensuring a space between the lid member and the base to accommodate the light-emitting element.

[0003] JP 2011-66169 A

[0004] Research and development is currently underway to further improve the performance of packages using the above-described dome-shaped lid members.

[0005] The present invention has as its technical object to improve the light extraction efficiency of a lid member used in a package including a light emitting element.

[0006] (1) The present invention is intended to solve the above-mentioned problems, and is a glass lid member used for a package including a light-emitting element, comprising a plate-shaped frame portion and a dome-shaped protrusion portion protruding from the frame portion, the protrusion portion having an inner surface and an outer surface, the protrusion portion comprising a top portion and a base portion formed integrally with the frame portion, an anti-reflection film formed on the inner surface of the protrusion portion, and a value obtained by dividing the thickness of the anti-reflection film formed on the base portion by the thickness of the anti-reflection film formed on the top portion is 0.75 or more and less than 1.

[0007] According to this configuration, by forming an anti-reflection film on the inner surface of the protrusion of the lid member, light emitted from the light-emitting element can be efficiently transmitted through the protrusion. This makes it possible to maximize the light extraction efficiency of the lid member used in the package. The thinner the anti-reflection film, the lower the anti-reflection effect. Therefore, by setting the value obtained by dividing the thickness of the anti-reflection film formed on the base of the protrusion by the thickness of the anti-reflection film formed on the top of the protrusion to be 0.75 or more and less than 1, the thickness of the anti-reflection film at the base of the protrusion can be made as close as possible to the thickness of the anti-reflection film at the top of the protrusion. Therefore, the lid member does not have any portions of the protrusion where the anti-reflection film is extremely thin. This makes it possible to improve the light extraction efficiency of the lid member.

[0008] (2) In the cover member described in (1) above, the thickness of the top of the protrusion may be thinner than the thickness of the base of the protrusion.

[0009] According to this configuration, by making the thickness of the top of the protrusion of the lid member thinner than the thickness of the base, it is possible to increase the transmittance of the protrusion. In addition, since the thickness of the base of the protrusion is thicker than the thickness of the top, it is possible to increase the strength of the base compared to the top. Therefore, it is possible to achieve both improved light extraction efficiency and ensure strength of the lid member.

[0010] (3) In the cover member described in (1) or (2) above, the frame portion may have a first main surface connected to the inner surface of the protrusion and a second main surface connected to the outer surface of the protrusion, and the anti-reflection film may be formed on the first main surface of the frame portion.

[0011] According to this configuration, the anti-reflection film formed on the first main surface of the frame portion has the function of alleviating the stress acting on the joint portion when the frame portion is joined to the base, so that the lid member can be joined to the base of the package without damaging it.

[0012] (4) In the lid member described in (3) above, a metal layer may be formed on the side of the anti-reflection film formed on the first main surface of the frame portion opposite to the first main surface side.

[0013] According to this configuration, by using this metal layer when forming a bonding material on the lid member, the bonding material adheres well to the metal layer, and as a result, the lid member and the package base can be bonded appropriately.

[0014] (5) In the cover member according to any one of (1) to (4) above, the anti-reflection film may include a hafnium oxide film.

[0015] If the anti-reflection film is a hafnium oxide film, the function of alleviating the stress acting on the joint when bonding the frame to the base can be significantly improved, and therefore the lid member can be bonded to the package base without being damaged.

[0016] (6) In the cover member according to any one of (1) to (5) above, a second anti-reflection film may be formed on the outer surface of the protruding portion.

[0017] According to this configuration, the light extraction efficiency of the cover member can be further improved.

[0018] (7) In the cover member described in (6) above, the thickness of the second anti-reflection film formed on the top may be greater than the thickness of the second anti-reflection film formed on the base.

[0019] (8) In the cover member described in any one of (1) to (7) above, the protrusion may protrude from the frame at a predetermined protrusion angle, and the protrusion angle may be 10° or more and 80° or less.

[0020] When a protrusion and a sputtering device are placed opposite each other and particles are scattered from the sputtering device toward the inner surface of the protrusion to form an anti-reflection film, an anti-reflection film having the designed thickness can be formed on the top of the protrusion. However, if the protrusion angle exceeds 80°, the amount of particles deposited on the base decreases, making it difficult to form an anti-reflection film having the designed thickness. In contrast, if the protrusion angle is 80° or less, it is possible to efficiently form anti-reflection film components on the base of the protrusion. This allows the anti-reflection film to be formed to a sufficient thickness, thereby improving the light extraction efficiency of the protrusion. Note that a protrusion angle of less than 10° is inadequate in terms of the space required to package the light-emitting element.

[0021] (9) In the lid member described in any one of (1) to (8) above, the protrusion may have an opening formed on the inner surface side, and a ratio L / H of an opening length L of the opening to a protrusion height H of the protrusion may be 1.2 or more and 8 or less.

[0022] When a sputtering device is placed facing the protrusion and particles are scattered from the sputtering device toward the inner surface of the protrusion to form an anti-reflective coating, an anti-reflective coating having the designed thickness can be formed on the top of the protrusion. However, if the ratio L / H is less than 1.2, the amount of particles deposited on the base is reduced, making it difficult to form an anti-reflective coating having the designed thickness. In contrast, if the ratio L / H is 1.2 or greater, it is possible to efficiently form the anti-reflective coating components on the base of the protrusion. This allows the anti-reflective coating to be formed to a sufficient thickness, thereby improving the light extraction efficiency of the protrusion. Note that a ratio L / H exceeding 8 is unsuitable from the perspective of the space required to package the light-emitting element.

[0023] (10) In the cover member described in (9) above, the opening may be configured in a rectangular shape.

[0024] (11) In the cover member described in any one of (1) to (10) above, the inner surface may have a first curved surface that is connected to the first main surface of the frame portion and that is convex toward the inside of the protrusion, a second curved surface that is convex toward the outside of the protrusion, and an inflection point located between the first curved surface and the second curved surface.

[0025] With this configuration, the shape of the lid member becomes smooth and can be made resistant to external impacts. Note that in the case of a lid member having this inflection point, there is a risk that the light extraction efficiency at the protrusion will decrease, so by specifying the protrusion angle and the ratio L / H of the opening length L of the opening and the protrusion height H of the protrusion, the light extraction efficiency at the protrusion can be increased.

[0026] (12) The present invention is intended to solve the above-mentioned problems, and is characterized by a package including a light-emitting element, a base supporting the light-emitting element, and a lid member according to any one of (1) to (11) above.

[0027] According to this configuration, by forming an anti-reflection film on the inner surface of the protrusion of the lid member, light emitted from the light-emitting element can be efficiently transmitted through the protrusion. This makes it possible to maximize the light extraction efficiency of the package. The thinner the anti-reflection film, the lower the anti-reflection effect. Therefore, by setting the value obtained by dividing the thickness of the anti-reflection film formed on the base of the protrusion by the thickness of the anti-reflection film formed on the top of the protrusion to be 0.75 or more and less than 1, the thickness of the anti-reflection film at the base of the protrusion can be made as close as possible to the thickness of the anti-reflection film at the top of the protrusion. Therefore, the lid member does not have any portions of the protrusion where the anti-reflection film is extremely thin. This makes it possible to improve the light extraction efficiency of the package.

[0028] According to the present invention, it is possible to improve the light extraction efficiency of a lid member used in a package including a light emitting element.

[0029] 1 is a perspective view of a package; a cross-sectional view of a package; a cross-sectional view of a base; a plan view of a base; a cross-sectional view of a lid member; a cross-sectional view of a main part of the lid member; a bottom view of the lid member; a cross-sectional view showing a preparatory step in a method of manufacturing a package; a cross-sectional view showing a preparatory step in a method of manufacturing a package; a cross-sectional view showing a film forming step in a method of manufacturing a package; a cross-sectional view showing a bonding step in a method of manufacturing a package; a cross-sectional view showing a bonding step in a method of manufacturing a package; a cross-sectional view showing a glass substrate for manufacturing a lid member for a package; a cross-sectional view showing another example of a lid member; a cross-sectional view showing another example of a lid member; a plan view showing another example of a lid member; a bottom view showing another example of a lid member; a cross-sectional view showing another example of a package in a preparatory step in a method of manufacturing a package; a cross-sectional view showing another example of a lid member; a cross-sectional view showing another example of a package; a cross-sectional view showing another example of a lid member; a cross-sectional view of a lid member; a cross-sectional view showing a preparatory step in a method of manufacturing a package; a cross-sectional view showing a preparatory step in a method of manufacturing a package.

[0030] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the lid member and package according to the present invention will now be described with reference to the accompanying drawings.

[0031] As shown in Figures 1 and 2, the package 1 includes a base 2, a light-emitting element 3 supported by the base 2, a lid member 4 that covers the base 2 and the light-emitting element 3, and a sealing portion 5 that hermetically joins the base 2 and the lid member 4.

[0032] 3 and 4 show the base 2 before the lid member 4 is bonded to it. The base 2 has a first main surface 2a that supports the light-emitting element 3, a second main surface 2b located opposite to the first main surface 2a, and a metal layer 6 formed on the first main surface 2a.

[0033] Examples of materials for the substrate 2 include ceramics such as aluminum nitride, aluminum oxide, silicon carbide, and silicon nitride, glass ceramics obtained by mixing and sintering these ceramics with glass powder, and alloys such as Fe—Ni—Co alloys, Cu—W alloys, and Kovar (registered trademark).

[0034] 4, the metal layer 6 has a frame shape surrounding the light-emitting element 3. The metal layer 6 is rectangular, but is not limited to this shape. The metal layer 6 may be circular, for example, so as to surround the light-emitting element 3.

[0035] The metal layer 6 includes three layers, namely, an underlayer, an intermediate layer, and a surface layer, in that order from the first main surface 2a side. Examples of metals used for the underlayer include Cr, Ta, W, Ti, Mo, Ni, and Pt. Examples of metals used for the intermediate layer include Ni, Pt, and Pd. Examples of metals used for the surface layer include Au, Sn, Ag, Ni, and Pt. The metal used for the metal layer 6 may be a single metal or an alloy.

[0036] Examples of methods for forming the metal layer 6 on the first main surface 2a of the substrate 2 include film formation methods such as sputtering, vacuum deposition, ion-assisted or ion-plating vacuum deposition, and CVD.

[0037] The light-emitting element 3 is fixed to the first main surface 2 a of the base 2. In this embodiment, the package 1 using an ultraviolet irradiating LED as the light-emitting element 3 is exemplified, but the light-emitting element 3 according to the present invention is not limited to this embodiment, and an infrared LED or a visible light LED can also be used.

[0038] 5 to 7 show the lid member 4 before being bonded to the base 2. The lid member 4 is manufactured by molding a portion of a glass plate. The glass used for the lid member 4 is preferably alkali-free glass, borosilicate glass, aluminosilicate glass, quartz glass, or crystallized glass. Alkali-free glass, borosilicate glass, or aluminosilicate glass can achieve both high transmittance and high processability during molding. Quartz glass can have significantly high transmittance in the ultraviolet range while maintaining processability during molding. Crystallized glass can achieve both high transmittance and high breaking strength.

[0039] When the glass is borosilicate glass, aluminosilicate glass, or alkali-free glass, the glass composition preferably contains, in mass %, SiO: 50 to 75%, AlO: 1 to 25%, BO: 1 to 30%, LiO + NaO + KO: 0 to 20%, and MgO + CaO + SrO + BaO: 0 to 20%. Glass compositions within the above composition ranges fall under these glass types.

[0040] In the case of glass-ceramics, the glass composition preferably contains, in mass %, SiO2: 60 to 80%, Al2O3: 3 to 30%, Li2O+Na2O+KO: 1 to 20%, and MgO+CaO+SrO+BaO: 5 to 20%, and is a low-thermal-expansion glass-ceramics in which β-quartz solid solution or β-spodumene precipitates as crystals from the inside of the glass. Here, low thermal expansion means a thermal expansion coefficient of -10×10 in the temperature range of 30 to 300°C. -7 / ℃~20×10 -7 / ℃.

[0041] As shown in Figures 2 and 5, the cover member 4 includes a plate-shaped frame portion 7, a dome-shaped protruding portion 8 protruding from the frame portion 7, a connecting portion 9 connecting the frame portion 7 and the protruding portion 8, a first anti-reflection film 10a, and a second anti-reflection film 10b.

[0042] The frame 7 has, for example, a constant thickness, but is not limited to this embodiment. The thickness of the frame 7 is, for example, 0.2 mm or more and 2 mm or less. The frame 7 has a first main surface 7a and a second main surface 7b located opposite the first main surface 7a. The surface roughness (arithmetic mean roughness) Ra of the first main surface 7a is preferably 1 nm or less, more preferably 0.5 nm or less, and even more preferably 0.3 nm or less. The surface roughness Ra of the second main surface 7b is preferably 1 nm or less, more preferably 0.5 nm or less, and even more preferably 0.3 nm or less.

[0043] The protrusion 8, together with the first main surface 2a of the base 2, forms a space for accommodating the light-emitting element 3. The protrusion 8 is formed at the center of the frame 7, but is not limited to this. The protrusion 8 has an inner surface 8a configured as a concave curved surface, an outer surface 8b configured as a convex curved surface, and an opening 8c formed on the inner surface 8a side. The protrusion 8 also includes a base 11, a midpoint 12, and a top 13. The base 11 is configured integrally with the connecting portion 9. The midpoint 12 is located between the base 11 and the top 13.

[0044] The base 11 of the protrusion 8 is defined as follows. As shown in FIG. 2 , a normal line (hereinafter referred to as the "first line") L1 is drawn to the apex 13, and a straight line (hereinafter referred to as the "second line") L2 is drawn along the second main surface 7b of the frame 7. The portion of the protrusion 8 from the intersection P2 of the first line L1 and the inner surface 8a of the protrusion 8 to the intersection P3 of the second line L2 and the inner surface 8a of the protrusion 8 is divided into four equal parts in a cross-sectional view. That is, straight lines L3 to L5 (hereinafter referred to as the third line L3, fourth line L4, and fifth line L5) are drawn from the intersection P1 of the first line L1 and the second line L2 so as to divide the portion of the protrusion 8 from the intersection P2 to the intersection P3 into four equal parts.

[0045] The portions divided by the straight lines L3 to L5 are referred to as a first portion, a second portion, a third portion, and a fourth portion, respectively, from the intersection point P2 toward the intersection point P1.

[0046] The base 11 is the boundary between the first portion and the second portion. That is, the base 11 is the portion where the third line L3 intersects with the protrusion 8. The portion where the third line L3 intersects with the inner surface 8a of the protrusion 8 is referred to as the first base 11a, and the portion where the third line L3 intersects with the outer surface 8b of the protrusion 8 is referred to as the second base 11b.

[0047] As shown in Figure 5, when a straight line (hereinafter referred to as the "sixth line") L6 is drawn from the intersection P1 between the first line L1 and the second line L2, forming an angle of 60° with the second line L2, the midway portion 12 is the portion where this sixth line L6 intersects with the protrusion 8.

[0048] Hereinafter, the distance from the intersection P2 between the first line L1 and the inner surface 8a of the protrusion 8 to the intersection P1 will be referred to as the protrusion height of the protrusion 8 and indicated by the symbol H. The protrusion height H of the protrusion 8 is, for example, 0.5 mm or more and 80 mm or less.

[0049] The outer diameter D of the protrusion 8 is the diameter of a circle formed by points at the position of the second base portion 11b, and is, for example, 2 mm to 150 mm. As shown in Fig. 5, the thickness of the protrusion 8 gradually decreases from the base portion 11 toward the apex 13. Therefore, the thickness Tmin of the apex 13 is smaller than the thickness Tmax of the base portion 11 (the distance between the first base portion 11a and the second base portion 11b).

[0050] The thickness Tmax of the base 11 is, for example, 0.19 mm or more and 1.9 mm or less. The thickness Tmin of the top 13 is, for example, 0.15 mm or more and 1.0 mm or less. The ratio Tmin / Tmax of the thickness Tmax of the base 11 to the thickness Tmin of the top 13 is preferably 0.08 or more and 0.9 or less, more preferably 0.1 or more and 0.8 or less, and even more preferably 0.2 or more and 0.5 or less.

[0051] 5, the protrusion 8 protrudes from the frame 7 at a predetermined protrusion angle θ. The protrusion angle θ is defined as follows.

[0052] On the first line L1, a straight line (hereinafter referred to as the "seventh line") L7 parallel to the second line L2 is drawn from point P4, which is at a height position that is half (H / 2) of the protrusion height H, and the intersection point P5 between this seventh line L7 and the inner surface 8a of the protrusion 8 is drawn. A straight line (hereinafter referred to as the "eighth line") L8 passing through the intersection points P3 and P5 is drawn, and the angle (acute angle) formed by this eighth line L8 and a ninth line L9 drawn along the first main surface 7a of the frame portion 7 is taken as the protrusion angle θ.

[0053] In this embodiment, the protrusion angle θ is preferably 10° or more and 80° or less, more preferably 20° or more and 70° or less, and even more preferably 20° or more and less than 40°.

[0054] The inner surface 8a and outer surface 8b of the protrusion 8 are configured as continuously curved surfaces from the base 11 to the top 13. The surface roughness Ra of the inner surface 8a is preferably 1 nm or less, more preferably 0.5 nm or less, and even more preferably 0.3 nm or less. The surface roughness Ra of the outer surface 8b is preferably 1 nm or less, more preferably 0.5 nm or less, and even more preferably 0.3 nm or less.

[0055] The opening 8c of the protrusion 8 is for inserting the light emitting element 3 provided on the base 2 into the inside of the protrusion 8 when the cover member 4 is fixed to the base 2. As shown in Fig. 7, the opening 8c of the protrusion 8 is configured in a circular shape, but is not limited to this shape.

[0056] The opening length L of the opening 8c (the diameter of the opening 8c in this embodiment) is, for example, 1.5 mm or more and 80 mm or less. The ratio L / H of the opening length L of the opening 8c to the protrusion height H of the protrusion 8 is preferably 1.2 or more, 1.6 or more, or 2.1 or more, and is preferably 8 or less, 5 or less, or 3 or less.

[0057] 2 and 5 , the connecting portion 9 has a curved shape to connect the base 11 and the frame portion 7. The connecting portion 9 has a first curved surface 9a that connects the first main surface 7a of the frame portion 7 and the inner surface 8a of the protruding portion 8, and a second curved surface 9b that connects the outer surface 8b of the protruding portion 8 and the second main surface 7b of the frame portion 7.

[0058] The radius of curvature of the first curved surface 9a is larger than the radius of curvature of the second curved surface 9b. The radius of curvature of the first curved surface 9a is preferably 0.5 mm or more and 1 mm or more, and preferably 5 mm or less and 4 mm or less. The radius of curvature of the second curved surface 9b is preferably 0.5 mm or more and 1 mm or more, and preferably 5 mm or less and 4 mm or less. The surface roughness Ra of the first curved surface 9a is preferably 1.0 nm or less, more preferably 0.5 nm or less, and even more preferably 0.3 nm or less. The surface roughness Ra of the second curved surface 9b is preferably 1 nm or less, more preferably 0.5 nm or less, and even more preferably 0.3 nm or less.

[0059] The first anti-reflection coating 10a is formed on the inner surface 8a of the protrusion 8 and the first main surface 7a of the frame 7. The first anti-reflection coating 10a has a multilayer structure that alternately includes, for example, a silicon oxide film (SiO2) as a first film and a hafnium oxide film (HfO2) as a second film.

[0060] 6 , in the first antireflection coating 10a, a portion 10a1 (hereinafter referred to as the “antireflection portion”) formed on the inner surface 8a of the protrusion 8 is configured so that the film thickness gradually decreases from the top 13 toward the base 11 of the protrusion 8. That is, the antireflection portion 10a1 has the thickest thickness Ta3 at the portion formed on the top 13, and the thickness Ta1 of the portion formed on the base 11 is thinner than the thickness Ta3 of the portion formed on the top 13.

[0061] The thickness Ta1 (see FIG. 6) of the first antireflection coating 10a at the base 11 of the protrusion 8 is preferably 0.12 μm or more and 0.64 μm or less. The thickness Ta2 of the first antireflection coating 10a at the midpoint 12 of the protrusion 8 is preferably 0.14 μm or more and 0.72 μm or less. The thickness Ta3 of the first antireflection coating 10a at the top 13 of the protrusion 8 is preferably 0.15 μm or more and 0.8 μm or less.

[0062] The value (Ta1 / Ta3) obtained by dividing the thickness Ta1 of the first anti-reflection coating 10a formed on the base 11 of the protrusion 8 by the thickness Ta3 of the first anti-reflection coating 10a formed on the top 13 of the protrusion 8 is preferably 0.75 or more and less than 1, and more preferably 0.85 or more and 0.95 or less.

[0063] The anti-reflection effect decreases as the thickness of the first anti-reflection coating 10a deviates from the design value. Therefore, by setting the value (Ta1 / Ta3) obtained by dividing the thickness Ta1 of the first anti-reflection coating 10a formed on the base 11 of the protrusion 8 by the thickness Ta3 of the first anti-reflection coatings 10a, 10b formed on the top 13 of the protrusion 8 to be 0.75 or more and less than 1, the thickness Ta1 of the first anti-reflection coating 10a on the base 11 of the protrusion 8 can be made as close as possible to the thickness Ta3 of the first anti-reflection coating 10a on the top 13 of the protrusion 8. Therefore, the lid member 4 does not have any portion on the protrusion 8 where the thickness of the first anti-reflection coating 10a is extremely thin. This improves the light extraction efficiency of the lid member 4.

[0064] In the first antireflection coating 10a, a portion 10a2 (hereinafter referred to as the "buffer portion") formed on the first main surface 7a of the frame portion 7 has a constant film thickness. In addition to the function of preventing reflection of ultraviolet rays, the buffer portion 10a2 also has the function of alleviating stress acting on the frame portion 7 when the lid member 4 is bonded to the base 2.

[0065] The second anti-reflection film 10b is formed on the outer surface 8b of the protrusion 8 and the second main surface 7b of the frame 7. The second anti-reflection film 10b has a multilayer film structure that alternately includes, for example, a silicon oxide film (SiO2) as a first film and a hafnium oxide film (HfO2) as a second film.

[0066] In the second antireflection film 10b, a portion 10b1 formed on the outer surface 8b of the protrusion 8 (hereinafter referred to as the "antireflection portion") is configured so that its thickness gradually decreases from the top 13 toward the base 11. That is, the antireflection portion 10b1 has the thickest thickness Tb3 at the portion formed on the top 13, and the thickness Tb1 of the portion formed on the base 11 is thinner than the thickness Tb3 of the portion formed on the top 13.

[0067] The thickness Tb1 of the second anti-reflection coating 10b at the base 11 of the protrusion 8 is preferably 0.12 μm or more and 0.64 μm or less. The thickness Tb2 of the second anti-reflection coating 10b at the midpoint 12 of the protrusion 8 is preferably 0.14 μm or more and 0.72 μm or less. The thickness Tb3 of the second anti-reflection coating 10b at the top 13 of the protrusion 8 is preferably 0.15 μm or more and 0.8 μm or less.

[0068] The value (Tb1 / Tb3) obtained by dividing the thickness Tb1 of the second anti-reflection film 10b formed on the base 11 of the protrusion 8 by the thickness Tb3 of the second anti-reflection film 10b formed on the top 13 of the protrusion 8 is preferably 0.75 or more and less than 1, and more preferably 0.85 or more and 0.95 or less.

[0069] The smaller the thickness of the second anti-reflection coating 10b, the lower the anti-reflection effect. Therefore, by setting the value (Tb1 / Tb3) obtained by dividing the thickness Tb1 of the second anti-reflection coating 10b formed on the base 11 of the protrusion 8 by the thickness Tb3 of the second anti-reflection coating 10b formed on the top 13 of the protrusion 8 to be 0.75 or more and less than 1, the thickness Tb1 of the second anti-reflection coating 19b on the base 11 of the protrusion 8 can be made as close as possible to the thickness Tb3 of the second anti-reflection coating 10b on the top 13 of the protrusion 8. Therefore, the lid member 4 does not have any portion on the protrusion 8 where the thickness of the second anti-reflection coating 10b is extremely thin. This can improve the light extraction efficiency of the lid member 4.

[0070] If the light extraction efficiency is sufficient, there is no need to form the second antireflection film 10b. However, if glass with poor weather resistance, such as borosilicate glass, is used for the lid member, there is a risk that the lid member 4 will deteriorate due to the external environment, resulting in a decrease in light extraction efficiency. In this case, instead of forming the second antireflection film 10b on the lid member 4, it is also possible to form a weather-resistant film such as an SiO2 film or an Al2O3 film. It is also possible to form a weather-resistant film such as an SiO2 film or an Al2O3 film laminated on the second antireflection film 10b.

[0071] As shown in Figures 2, 5, and 7, the buffer portion 10a2 of the first antireflection coating 10a includes a metal layer 14 and a bonding portion 15. The Young's modulus of the buffer portion 10a2 is preferably 250 GPa or less, more preferably 200 GPa or less, even more preferably 150 GPa or less, and particularly preferably 100 GPa or less. By specifying the upper limit in this manner, the buffering properties of the buffer portion 10a2 can be improved, and stress caused by the difference in thermal expansion coefficient between the bonding portion 15 and the cover member 4 (frame portion 7) can be alleviated. The thermal expansion coefficient of the frame portion 7 is smaller than that of the bonding portion 15. Furthermore, the thermal expansion coefficient of the frame portion 7 is smaller than that of the base 2.

[0072] The thickness of the buffer section 10a2 is preferably 0.1 μm or more, 0.2 μm or more, and preferably 1 μm or less, 0.8 μm or less. By specifying the lower limit in this way, the buffering properties of the buffer section 10a2 can be further improved, and the effect of alleviating stress caused by the difference in thermal expansion coefficient between the joint section 15 and the cover member 4 (frame section 7) can be obtained. Furthermore, by specifying the upper limit in this way, the manufacturing cost of the buffer section 10a2 can be reduced.

[0073] As shown in Figures 5 and 7, the metal layer 14 is formed so as to overlap the buffer section 10a2. The metal layer 14 is formed on the surface of the buffer section 10a2 opposite to the surface of the buffer section 10a2 that contacts the first main surface 7a of the frame section 7. As shown in Figure 7, the metal layer 14 has a rectangular frame shape corresponding to the shape of the metal layer 6 of the base 2. The shape of the metal layer 14 is not limited to this embodiment. The metal layer 14 may have various frame shapes such as a circular shape. The metal layer 14 includes three layers: a base layer, an intermediate layer, and a surface layer, in that order from the buffer section 10a2 side.

[0074] Examples of metals used for the underlayer include Cr, Ta, W, Ti, Mo, Ni, and Pt. When Cr is used for the underlayer, the Young's modulus of the underlayer is preferably 279 GPa or less. Examples of metals used for the intermediate layer include Ni, Pt, and Pd. Examples of metals used for the surface layer include Au, Sn, Ag, Ni, and Pt. The metal used for the metal layer 14 may be a single metal or an alloy.

[0075] 5 and 7, the bonding portion 15 is configured in a layered form so as to overlap the metal layer 14. As shown in Fig. 5, the bonding portion 15 contacts a portion of the metal layer 14 opposite to the portion in contact with the buffer section 10a2. As shown in Fig. 7, the bonding portion 15 has a rectangular frame shape so as to correspond to the shapes of the buffer section 10a2 and the metal layer 14. The shape of the bonding portion 15 is not limited to that of this embodiment, and may be a circle or any other frame shape.

[0076] The joint 15 is made of a metallic joint material. Commercially available solder materials or brazing filler metals can be used as the metallic joint material. Examples of metallic joint materials include an Au—Sn alloy, a Pb—Sn alloy, an Au—Ge alloy, and an Sn—Ni alloy. By making the width of the joint 15 narrower than the width of the buffer portion 10a2, the influence of stress due to the difference in thermal expansion coefficient between the joint 15 and the lid member 4 can be reduced. In this embodiment, a case where an Au—Sn alloy is used as the metallic joint material will be described.

[0077] The sealing portion 5 is formed by integrally joining the metal layer 6 of the base 2 and the metal layer 14 of the lid member 4 at a joint 15 .

[0078] Next, a description will be given of a method for manufacturing the package 1. This method includes a preparation step of preparing the base body 2 and the lid member 4, and a joining step of joining the base body 2 and the lid member 4 together.

[0079] In the preparation step, after the metal layer 6 is formed on the first main surface 2a of the base 2, the light emitting element 3 is mounted on this first main surface 2a.

[0080] In the preparation step, the lid member 4 is formed by forming the protrusions 8 on the glass plate, and then the first antireflection film 10a is formed on the lid member 4. Then, the metal layer 14 and the bonding portion 15 are formed on the buffer portion 10a2 of the first antireflection film 10a. Note that by forming the second antireflection film 10b on the lid member 4, it is possible to further improve the light extraction efficiency.

[0081] The process for manufacturing the lid member 4 will be described below with reference to Figures 8 to 10. This process includes a molding process and a film forming process.

[0082] 8 shows a forming device used in the forming process. The forming device 16 includes a support table 17 that supports the glass sheet GS, a mask member 18 that is placed on top of the glass sheet GS supported by the support table 17, and a heat source 19 that thermally deforms a portion of the glass sheet GS to form the protrusion 8 of the lid member 4. The forming device 16 further includes a pressing member 20 that presses the support table 17 and the mask member 18 in a direction that brings them closer to each other, and an external force generating device 21 that applies an external force to a portion of the glass sheet GS.

[0083] The support base 17 has a support portion 17a that supports the glass sheet GS and a space portion 17b that has an opening surrounded by the support portion 17a and allows for thermal deformation of part of the glass sheet GS. The support portion 17a of the support base 17 has a support surface that supports the main surface of the glass sheet GS. In this embodiment, the opening of the support base 17 has a circular opening edge E1, but may have an opening edge of a polygonal shape such as a triangular shape or a rectangular shape, an elliptical shape, or the like.

[0084] The space 17b of the support base 17 may be formed by a through-hole or a recess having an inner bottom. The space 17b of the support base 17 is configured to mold the entire protrusion 8 of the lid member 4 in a non-contact state. Examples of materials that form the support base 17 include metals and ceramics.

[0085] In addition to the above configuration, a support jig for supporting the glass sheet GS may be provided in the space 17b to accurately form the shape of the lid member 4. The support jig is made of metal or ceramics. As described above, it is preferable to form the entire protrusion 8 of the lid member 4 in a non-contact state. However, by improving the quality of the surface of the support jig that comes into contact with the glass sheet GS (reducing surface roughness and surface waviness), the lid member 4 can be accurately formed even when a support jig is used.

[0086] 8, the mask member 18 has a through hole 18a. The through hole 18a of the mask member 18 in this embodiment has a circular inner peripheral edge E2, but may have an inner peripheral edge that is, for example, a polygonal shape such as a triangular shape or a rectangular shape, or an elliptical shape.

[0087] The support base 17 and the mask member 18 are configured so that at least a part of the inner peripheral edge E2 of the through hole 18a in the mask member 18 is located inside the opening edge E1 of the support base 17. Specifically, the support base 17 and the mask member 18 are configured so that the entire inner peripheral edge E2 of the through hole 18a in the mask member 18 is located inside the opening edge E1 of the support base 17.

[0088] When the opening area of ​​the opening of the support base 17 is taken as 100%, the cross-sectional area of ​​the through hole 18a of the mask member 18 is preferably 95% or less, and more preferably 80% or less. At least a part of the inner peripheral edge E2 of the through hole 18a in the mask member 18 is preferably positioned 1 mm or more inward from the opening edge E1 of the support base 17, and more preferably 3 mm or more inward.

[0089] The mask member 18 is preferably made of a material having a thermal conductivity of 1 W / (m·K) or less at 600°C. Ceramics, for example, are suitable as the material for the mask member 18. The thickness of the mask member 18 is preferably 1 mm or more. The mask member 18 of this embodiment has an outer shape that covers the entire outer periphery of the glass sheet GS.

[0090] The heating source 19 is arranged to heat the glass sheet GS from the mask member 18 side. In this embodiment, the heating source 19 is a burner that sprays a flame FL toward the glass sheet GS. By using a burner, the glass sheet GS can be softened relatively quickly. The heating method of the heating source 19 may be, for example, resistance heating or laser heating. The heating source 19 may also be configured by combining heating sources of different heating methods.

[0091] The pressing member 20, for example, presses the mask member 18 toward the support base 17. Examples of a pressing mechanism that presses the pressing member 20 include a fluid cylinder and a linear actuator. Note that the pressing member 20 can also be configured to press the support base 17 against the fixed mask member 18.

[0092] An exhaust device, for example, can be used as the external force generator 21. The exhaust device creates a negative pressure in the space 17b of the support base 17 by discharging gas present in the space 17b of the support base 17. This causes a portion of the glass sheet GS to be sucked into the space 17b of the support base 17, thereby promoting thermal deformation of the portion of the glass sheet GS. A pump using a Venturi mechanism, for example, is suitable as the exhaust device.

[0093] The external force generator 21 is not limited to an exhaust device, but may be a high-pressure gas generator that sprays high-pressure gas toward a portion of the glass sheet GS from the mask member 18 side. This pressurizes the portion of the glass sheet GS toward the space 17b of the support base 17, thereby promoting thermal deformation of the portion of the glass sheet GS. Alternatively, a pump and a high-pressure gas generator may be used in combination to promote thermal deformation of the portion of the glass sheet GS.

[0094] 8 and 9 , in the forming process, first, a mask member 18 is placed on top of a glass sheet GS supported on a support table 17. In this case, at least a part of the inner peripheral edge E2 of the through hole 18a of the mask member 18 is placed inside the opening edge E1 of the support table 17. Thereafter, a pressing member 20 presses the support table 17 and the mask member 18 so that they abut against each other. This makes it possible to prevent the glass sheet GS sandwiched between the support table 17 and the mask member 18 from shifting in position.

[0095] Next, in the forming step, the glass sheet GS is heated from the mask member 18 side by the heating source 19. As a result, a part of the glass sheet GS is thermally deformed, and the protrusion 8 is formed.

[0096] In the above-described forming process, the opening edge E1 of the support base 17 can be covered with the mask member 18. This allows the connecting portion 9 of the lid member 4 to be formed by thermal deformation of the glass sheet GS along the inner peripheral edge E2 of the through hole 18a of the mask member 18. In other words, the connecting portion 9 of the lid member 4 is formed without contacting the support base 17. Through this forming process, the lid member 4 having the frame portion 7, the protruding portion 8, and the connecting portion 9 is formed.

[0097] In addition to the above, the method for forming the protrusions 8 on the lid member 4 (the method for manufacturing the lid member 4) can also employ a method in which the glass sheet GS is placed on a metal or ceramic mold having a recess, and the glass sheet GS is hot-pressed using a metal or ceramic mold having a protrusion that fits into the recess. The heating temperature in this hot-pressing is preferably equal to or higher than the yield point of the glass sheet GS, and more preferably equal to or higher than the softening point of the glass sheet GS.

[0098] After the forming process is completed, the film forming process is carried out. Fig. 10 shows a film forming apparatus used in the film forming process. In this embodiment, a sputtering apparatus such as a magnetron sputtering apparatus is used as the film forming apparatus, but the present invention is not limited to this configuration, and a film forming apparatus that performs other physical vapor deposition methods such as vacuum evaporation may also be used.

[0099] The film forming apparatus 22 includes a vacuum chamber 23 and targets 24a and 24b for scattering particles that will be the film forming materials for the anti-reflection films 10a and 10b.

[0100] The targets 24a and 24b are accommodated inside the vacuum chamber 23. The interior space of the vacuum chamber 23 is set to a predetermined vacuum level by a vacuum pump. An inert gas such as argon gas can be supplied into the vacuum chamber 23.

[0101] The targets 24a, 24b include a first target 24a for forming the first anti-reflection coating 10a on the lid member 4 and a second target 24b for forming the second anti-reflection coating 10b on the lid member 4. In addition to these targets 24a, 24b, a target (not shown) for forming the metal layer 14 is also placed in the vacuum chamber 23.

[0102] The first target 24a and the second target 24b include a plurality of targets for forming the first film (SiO 2 ) and the second film (HfO 2 ) of the first anti-reflection coating 10a and the second anti-reflection coating 10b.

[0103] 10 , in the film formation process, the lid member 4 is housed in a vacuum chamber 23. Thereafter, particles scattered from the first target 24a are caused to adhere to the inner surface 8a of the protruding portion 8 of the lid member 4 and the first main surface 7a of the frame portion 7, thereby forming a first antireflection coating 10a. Similarly, particles scattered from the second target 24b are caused to adhere to the outer surface 8b of the protruding portion 8 of the lid member 4 and the second main surface 7b of the frame portion 7, thereby forming a second antireflection coating 10b.

[0104] The amount of particles adhering to the protruding portion 8 of the lid member 4 is greatest at the top 13 and gradually decreases toward the base 11. The difference in the amount of particles adhering to the protruding portion 8 is due to the influence of the protruding angle θ of the protruding portion 8.

[0105] After the anti-reflection coatings 10a and 10b are formed on the lid member 4, the metal layer 14 is formed so as to overlap the buffer portion 10a2 of the first anti-reflection coating 10a. The metal layer 14 is formed by depositing particles scattered from a target (not shown) for forming the metal layer 14 onto the buffer portion 10a2 using the above-mentioned film deposition apparatus 22. The metal layer 14 is formed into a frame shape by depositing the particles onto the buffer portion 10a2 through a mask member.

[0106] Thereafter, the bonding portion 15 is formed so as to overlap the metal layer 14. The bonding portion 15 is formed by a process (coating process) in which, for example, a paste-like metal-based bonding material is coated on the metal layer 14 so as to overlap the metal layer 14. Specific examples of the coating process include a printing method using a mask (screen printing method) and a coating method using a dispenser.

[0107] The bonding portion 15 may be formed by any method other than the above, for example, by arranging a molded body of a metal-based bonding material formed in advance into a predetermined frame shape so that it overlaps the metal layer 14 on the first main surface 7a of the frame portion 7.

[0108] After the metal-based bonding material for the bonding portion 15 is applied to the first main surface 7a of the frame portion 7, a heat treatment process is carried out to fix the metal-based bonding material to the metal layer 14 on the first main surface 7a. The heat treatment process includes a heating process and a cooling process.

[0109] In the heating step, the lid member 4 is heated using a heating device such as a reflow furnace, thereby melting the metal-based bonding material. The heating step may be performed, for example, in a state where the furnace is filled with nitrogen. In the heating step, the lid member 4 is heated to a temperature of 300° C. or higher.

[0110] In the cooling step, the metal-based bonding material melted on the first main surface 7a of the frame 7 is cooled and solidified. The cooling step is preferably performed by slow cooling at a cooling rate of 50°C / min. In the cooling step, stress is generated in the lid member 4 due to the difference in thermal expansion coefficient between the frame 7 and the bonding portion 15, but the buffer portion 10a2 of the first antireflection film 10a can relieve this stress.

[0111] 11 , in the joining step, the lid member 4 manufactured through the preparation step is laid on the base body 2. Specifically, the first main surface 7 a of the frame portion 7 of the lid member 4 is placed opposite the base body 2, and the joining portion 15 is brought into contact with the metal layer 6 formed on the first main surface 2 a of the base body 2.

[0112] 12, the pressing member 25 is placed on the frame portion 7 of the cover member 4. The pressing member 25 has a weight 25a and a support member 25b that supports the weight 25a. The weight 25a and the support member 25b are made of, for example, metal or ceramic.

[0113] The support member 25b has a first support portion 25b1 that supports the weight 25a, and a second support portion 25b2 that supports the first support portion 25b1.

[0114] The first support portion 25b1 has a support surface (upper surface) on which the weight 25a is placed. The second support portion 25b2 includes a plurality of rod-shaped members. The second support portion 25b2 protrudes downward from the lower surface of the first support portion 25b1.

[0115] The second support portion 25b2 has a contact portion 25b3 that comes into contact with the frame portion 7 of the lid member 4. The contact portion 25b3 is configured in a pointed shape. The contact portion 25b3 comes into contact with the second main surface 7b of the frame portion 7 via the second anti-reflection film 10b.

[0116] Pressing member 25 presses lid member 4 while standing on its own on lid member 4, as contact portions 25b3 of multiple second support portions 25b2 come into contact with frame portion 7. Pressing lid member 4 with pressing member 25 allows joint portion 15 formed on frame portion 7 of lid member 4 and metal layer 6 formed on first main surface 2a of base 2 to be tightly attached to each other.

[0117] Thereafter, the metal layer 6 and the joint 15 are heated while being pressed together (heating step). As a result, the metal-based joint material of the joint 15 is melted. In this heating step, the pointed contact portion 25b3 of the second support portion 25b2 comes into contact with the frame portion 7 of the cover member 4, so that the contact area between the contact portion 25b3 and the frame portion 7 can be made as small as possible. This makes it possible to minimize heat transfer from the frame portion 7 to the second support portion 25b2 of the pressing member 25.

[0118] The molten metal-based bonding material is then cooled and solidified (cooling step). During the cooling step, stress is generated in the frame 7 due to the difference in thermal expansion coefficient between the base 2 and the frame 7 of the lid member 4. In this case, the buffer portion 10a2 of the first anti-reflection film 10a deforms to relieve this stress. This reduces damage to the frame 7.

[0119] When the cooling step is completed, the sealing portion 5 is formed by integrally joining the metal layer 6 of the base 2 and the metal layer 14 of the lid member 4 at the joint 15. In this way, the package 1 that maintains airtightness is completed.

[0120] 13 shows an example of a glass substrate for manufacturing the lid member 4. The glass substrate G includes a frame 7, multiple protrusions 8 protruding from the frame 7, and anti-reflection coatings 10a and 10b. Each protrusion 8 has the same configuration as the protrusions 8 of the lid member 4 described above. Each protrusion 8 is formed by thermally deforming multiple locations of a large glass sheet GS using the molding device 16 described above. By cutting this glass substrate G along the cutting lines CL, multiple lid members each having the protrusions 8, the frame 7, and the anti-reflection coatings 10a and 10b can be efficiently manufactured. Note that a metal layer 14 and a bonding portion 15 may be formed on the first anti-reflection coating 10a.

[0121] 14 shows another example of a lid member. In this example, the lid member 4 includes a frame 7, a plurality of protrusions 8 protruding from the frame 7, anti-reflection coatings 10a and 10b, a metal layer 14, and a bonding portion 15. Each component of this lid member 4 has the same configuration as the lid member 4 described above ( FIG. 5 ). When a plurality of light-emitting elements 3 are mounted on the base 2, this lid member 4 can individually seal each light-emitting element 3 with the plurality of protrusions 8.

[0122] 15 shows another example of the lid member. In this example, the inner surface 8a of the lid member 4 has a first curved surface 8a1 and a second curved surface 8a2 with different radii of curvature, and a boundary portion 8a3 located between the first curved surface 8a1 and the second curved surface 8a2. The radius of curvature of the first curved surface 8a1 formed on the base 11 side of the protrusion 8 is smaller than the radius of curvature of the second curved surface 8a2 formed on the top 13 side of the protrusion 8.

[0123] The outer surface 8b of the cover member 4 has a first curved surface 8b1 and a second curved surface 8b2 with different radii of curvature, and a boundary portion 8b3 located between the first curved surface 8b1 and the second curved surface 8b2. The radius of curvature of the first curved surface 8b1 formed on the base 11 side of the protrusion 8 is smaller than the radius of curvature of the second curved surface 8b2 formed on the top 13 side of the protrusion 8.

[0124] 16 and 17 are plan views showing other examples of the lid member. In this example, the lid member 4 has multiple protrusions 8 arranged in multiple rows and columns, antireflection coatings 10a and 10b (the first antireflection coating 10a is not shown), a metal layer 14 (not shown), and a bonding portion 15 (not shown). The lid member 4 shown in FIG. 16 has multiple protrusions 8 configured in a circular shape in plan view. On the other hand, the lid member 4 shown in FIG. 17 has multiple protrusions 8 configured in a rectangular shape in plan view. Note that for a lid member 4 having multiple protrusions 8 arranged in multiple rows and columns, scribe lines are made on the smooth surface between adjacent protrusions 8, and the lid member 4 is fractured along the scribe lines, or diced using a blade dicing method or laser ablation method, thereby obtaining multiple lid members and lid members of any shape.

[0125] Fig. 18 is a bottom view showing another example of the lid member. In this example, the lid member 4 has a protrusion 8 configured in a quadrangular shape in a plan view, similar to the example shown in Fig. 17. With this configuration, the opening 8c of the protrusion 8 is configured in a quadrangular shape (e.g., a square shape). When the opening 8c is configured in a square shape, the opening length L corresponds to the length of one side of the square. When the opening 8c is configured in a rectangular shape, the opening length L corresponds to the length of the long side of the rectangle.

[0126] 19 shows another example of a method for manufacturing a lid member (a preparation step in a package manufacturing method). This example shows a step of forming a bonding portion 15 on a glass substrate G on which anti-reflection films 10a, 10b and a metal layer 14 have been formed. Specifically, the case where the glass substrate G is fixed to a support device 26 when forming the bonding portion 15 by screen printing will be described.

[0127] The support device 26 includes a support plate 27 that supports the glass substrate G, and a suction table 29 that supports the support plate 27 .

[0128] The support plate 27 is configured to be detachable from the suction stand 29. The support plate 27 has openings 28 into which the protruding portions 8 and connecting portions 9 of the glass substrate G can be inserted. By inserting the protruding portions 8 and connecting portions 9 into the openings 28 with the protruding portions 8 of the glass substrate G facing downward, the support plate 27 can support only the frame portion 7 of the glass substrate G without coming into contact with the protruding portions 8 and connecting portions 9.

[0129] The suction table 29 includes a support portion 30 that supports the support plate 27 and a suction port 31 for fixing the glass substrate G to the support plate 27. The support portion 30 has a support surface 30a that supports the peripheral edge portion of the support plate 27.

[0130] The suction table 29 has a space 29a between the support plate 27 supported by the support portion 30 and the suction port 31. The suction port 31 is connected to a suction device (exhaust device) such as a pump (not shown).

[0131] The suction table 29 creates a negative pressure in the space 29a by discharging gas present in the space 29a through the suction port 31 while supporting the support plate 27 on which the glass substrate G is placed by the support portion 30. As a result, the glass substrate G is sucked into the space 29a through the opening 28 of the support plate 27, and is fixed to the support plate 27. Thereafter, a paste-like metallic bonding material for the bonding portion 15 is applied by screen printing so as to overlap the metal layer 14 of the glass substrate G.

[0132] By supporting the glass substrate G by the supporting device 26 as described above, it becomes possible to form the bonding portion 15 with high precision.

[0133] Fig. 20 shows another example of a package. In this example, the package 1 includes a base 2 on which a plurality of light-emitting elements 3 are mounted, and the lid member 4 illustrated in Fig. 14. The lid member 4 individually seals each of the light-emitting elements 3 mounted on the base 2 with a plurality of protrusions 8 and a sealing portion 5.

[0134] According to the package 1 according to the present embodiment described above, by forming anti-reflection films 10a, 10b on the inner surface 8a and outer surface 8b of the protrusion 8 of the lid member 4, the light emitted from the light-emitting element 3 can be efficiently transmitted through the protrusion 8. This makes it possible to maximize the light extraction efficiency of the package 1 in which the lid member 4 is used.

[0135] In this cover member 4, the value (Ta1 / Ta3) obtained by dividing the thickness Ta1 of the first anti-reflection film 10a formed on the base 11 of the protrusion 8 by the thickness Ta3 of the first anti-reflection film 10a formed on the top 13 of the protrusion 8 is set to be 0.75 or more and less than 1, thereby improving the light extraction efficiency.

[0136] The present invention is not limited to the configuration of the above-described embodiment, nor is it limited to the above-described effects. The present invention can be modified in various ways without departing from the spirit of the present invention.

[0137] In the above embodiment, the lid member 4 and the glass substrate G are shown to have the first anti-reflection coating 10a and the second anti-reflection coating 10b formed thereon, but the present invention is not limited to this configuration. The lid member 4 and the glass substrate G according to the present invention may have only the first anti-reflection coating 10a.

[0138] In the above embodiment, the cover member 4 has the protrusion 8 configured so that the thickness of the top 13 is thinner than the thickness of the base 11, but the present invention is not limited to this configuration. The present invention is also applicable to a cover member 4 having a protrusion 8 whose thickness is constant from the base 11 to the top 13.

[0139] 21 shows another example of the lid member. In this example, the inner surface 8a of the lid member 4 has a first curved surface 8a1 that is convex toward the inside of the protruding portion 8, a second curved surface 8a2 that is convex toward the outside of the protruding portion 8, and an inflection point 8a3 located between the first curved surface 8a1 and the second curved surface 8a2. The first curved surface 8a1 is formed closer to the base 11 of the protruding portion 8 than the second curved surface 8a2. The center of curvature of the first curved surface 8a1 is located outside the protruding portion 8. The second curved surface 8a2 is formed closer to the apex 13 than the first curved surface 8a1. The center of curvature of the second curved surface 8a2 is located inside the protruding portion 8.

[0140] The outer surface 8b of the cover member 4 has a first curved surface 8b1 that is convex toward the inside of the protruding portion 8, a second curved surface 8b2 that is convex toward the outside of the protruding portion 8, and an inflection point 8b3 located between the first curved surface 8b1 and the second curved surface 8b2. The first curved surface 8b1 is formed closer to the base 11 of the protruding portion 8 than the second curved surface 8b2. The center of curvature of the first curved surface 8b1 is located outside the protruding portion 8. The second curved surface 8b2 is formed closer to the apex 13 of the protruding portion 8 than the first curved surface 8b1. The center of curvature of the second curved surface 8b2 is located inside the protruding portion 8. The inflection points 8a3 and 8b3 are located above (toward the apex 13) the second main surface 7b of the frame portion 7.

[0141] The inflection points 8a3, 8b3 on the inner surface 8a and the outer surface 8b can be formed on the cover member 4 by a molding device and a molding method shown in FIGS.

[0142] When the lid member 4 according to this example has protrusions 8 with inflection points 8a3 and 8b3 formed therein, setting the protrusion angle θ to be equal to or greater than 10° and equal to or less than 80° makes it possible to increase the light extraction efficiency of the lid member 4. The protrusion angle θ is more preferably equal to or greater than 20° and equal to or less than 70°, and even more preferably equal to or greater than 20° and less than 40°.

[0143] In this example, the definition of the protrusion angle θ differs from that of the embodiment shown in Fig. 5. In this example, the protrusion angle θ is the angle (acute angle) formed between the tangent line L8 at the inflection point 8a3 and the first main surface 7a of the frame portion 7. Specifically, the protrusion angle θ is the angle (acute angle) formed between the tangent line L8 at the inflection point 8a3 and a ninth line L9 drawn along the first main surface 7a of the frame portion 7. In this example, the opening length L and protrusion height H of the opening 8c are the same as those of the embodiment shown in Fig. 5.

[0144] In this example, the anti-reflection films (10a, 10b) are not necessarily essential components, but it is preferable to provide the anti-reflection films (10a, 10b), and the preferred materials and thicknesses of the anti-reflection films (10a, 10b) are the same as those in the embodiment shown in Fig. 5. In this example, the preferred thicknesses (thickness of the base 11, thickness of the top 13) and outer diameters of the protrusions 8 are the same as those in the embodiment shown in Fig. 5.

[0145] 22 to 26 show other examples of the package and lid member. In this example, the shape of the lid member differs from that of the above-described embodiment. As shown in FIGS. 22 to 24, the top 13 of the lid member 4 in this example is flat. By forming the flat top 13 on the lid member 4 in this manner, anti-reflection films 10a, 10b of uniform thickness can be formed on the inner and outer surfaces 8a, 8b of the lid member 4 associated with the top 13. Furthermore, by forming the flat top 13 on the lid member 4, the distance D1 between the top 13 and the light-emitting element 3 can be minimized. In addition, light emitted from the light-emitting element 3 is more likely to be perpendicularly incident on the flat top 13. Therefore, the light extraction efficiency of the lid member 4 can be significantly improved.

[0146] Next, a method for manufacturing the package 1 (a method for manufacturing the lid member 4) in this example will be described. In this method, the preparation step in the method for manufacturing the package 1 differs from the example shown in Figures 8 and 9. As shown in Figure 25, the molding device 16 includes a support table 17, a mask member 18, a heat source 19, a pressing member 20, an external force generator 21, and a molding die (support jig) 32. The configurations of the support table 17, the mask member 18, the heat source 19, the pressing member 20, and the external force generator 21 are the same as those shown in Figure 8.

[0147] The forming die 32 is disposed in the space 17b of the support base 17. The forming die 32 has a forming surface 32a that forms a portion of the sheet glass GS that is softened by heating. The forming surface 32a is configured to have a flat surface shape. The surface roughness (arithmetic mean roughness) Ra of the forming surface 32a is, for example, 0.1 nm or more and 10 nm or less.

[0148] 26 , in the forming process, a mask member 18 is placed on top of a glass sheet GS supported on a support base 17. In this case, at least a part of an inner peripheral edge E2 of the through hole 18a of the mask member 18 is placed inside an opening edge E1 of the support base 17. Thereafter, a pressing member 20 presses the support base 17 and the mask member 18 in a direction to bring them closer to each other.

[0149] Next, the glass sheet GS is heated from the mask member 18 side by the heating source 19. This causes a portion of the glass sheet GS to thermally deform. At this time, a portion of the deformed glass sheet GS comes into contact with the forming surface 32a of the forming mold 32. As a result, the portion of the glass sheet GS is formed into a flat plate shape. This forming process forms the cover member 4 having the frame portion 7, the protrusion portion 8 including the flat top portion 13, and the connecting portion 9.

[0150] The package 1 can be manufactured by carrying out the film forming process and bonding process illustrated in FIGS. 10 to 12 on this lid member 4 .

[0151] Examples of the present invention will be described below, but the present invention is not limited to these examples.

[0152] In order to confirm the effects of the present invention, the inventors conducted a test to measure the light extraction efficiency of a lid member. In this test, lid members (samples No. 1 to No. 8) of examples and comparative examples each having an anti-reflection coating on the inner surface of the protrusion were prepared, and the light extraction efficiency was measured for each example. For each sample, a lid member having the shape shown in FIG. 21 was used.

[0153] The light extraction efficiency was calculated by measuring the energy EN1 of light (wavelength 265 nm) emitted from the light-emitting element without passing through the lid member, measuring the energy EN2 of the light (wavelength 265 nm) emitted from the light-emitting element when it was transmitted through the lid member, and then calculating the ratio of these energies (EN2 / EN1).

[0154] The test conditions and measurement results are shown in Table 1.

[0155] In Table 1, the light extraction efficiency (EN2 / EN1) of the comparative example of Sample No. 7 was used as the standard, and in the examples, light extraction efficiencies of 1.1 times or more of the standard were evaluated as good (◯), and those less than 1.1 times were evaluated as poor (×).

[0156] As shown in Table 1, it was found that the light extraction efficiency was improved when the value (Ta1 / Ta3) obtained by dividing the thickness Ta1 of the first antireflection film formed at the base of the protrusion by the thickness Ta3 of the first antireflection film formed at the top of the protrusion was 0.75 or more and less than 1 (Samples No. 1 to No. 6).

[0157] DESCRIPTION OF SYMBOLS 1 Package 2 Base 3 Light-emitting element 4 Lid member 7 Frame 7a First main surface of frame 7b Second main surface of frame 8 Protrusion 8a Inner surface of protrusion 8a1 First curved surface of inner surface of protrusion 8a2 Second curved surface of inner surface of protrusion 8a3 Inflection point of inner surface of protrusion 8b Outer surface of protrusion 8c Opening of protrusion 10a First anti-reflection film 10b Second anti-reflection film 11 Base 13 Top 14 Metal layer Ta1 Thickness of first anti-reflection film at base of protrusion Ta3 Thickness of first anti-reflection film at top of protrusion Tb1 Thickness of second anti-reflection film at base of protrusion Tb3 Thickness of second anti-reflection film at top of protrusion Tmin Thickness of top of protrusion Tmax Thickness of base of protrusion θ Protrusion angle

Claims

1. A glass lid member used for a package including a light-emitting element, comprising: a plate-shaped frame portion and a dome-shaped protrusion portion protruding from the frame portion, the protrusion portion having an inner surface and an outer surface, the protrusion portion comprising a top portion and a base portion integral with the frame portion, an anti-reflection film being formed on the inner surface of the protrusion portion, and a value obtained by dividing the thickness of the anti-reflection film formed on the base portion by the thickness of the anti-reflection film formed on the top portion is equal to or greater than 0.75 and less than 1.

2. The cover member according to claim 1, wherein the thickness of the top of the protrusion is thinner than the thickness of the base of the protrusion.

3. A cover member as described in claim 1 or 2, characterized in that the frame portion has a first main surface connected to the inner surface of the protrusion and a second main surface connected to the outer surface of the protrusion, and the anti-reflection film is formed on the first main surface of the frame portion.

4. The cover member according to claim 3, characterized in that a metal layer is formed on the side of the anti-reflection film formed on the first main surface of the frame portion opposite to the first main surface side.

5. The cover member according to claim 1 or 2, characterized in that the anti-reflection film includes a hafnium oxide film.

6. The cover member according to claim 1 or 2, characterized in that a second anti-reflection film is formed on the outer surface of the protrusion.

7. The cover member according to claim 6, characterized in that the thickness of the second anti-reflection film formed on the top portion is greater than the thickness of the second anti-reflection film formed on the base portion.

8. The cover member according to claim 1 or 2, characterized in that the protrusion protrudes from the frame at a predetermined protrusion angle, and the protrusion angle of the protrusion is greater than or equal to 10° and less than or equal to 80°.

9. A cover member as described in claim 1 or 2, characterized in that the protrusion has an opening formed on the inner surface side, and a ratio L / H of an opening length L of the opening to a protruding height H of the protrusion is 1.2 or more and 8 or less.

10. The cover member according to claim 9, wherein the opening is configured in a rectangular shape.

11. A cover member as described in claim 1 or 2, characterized in that the inner surface has a first curved surface that is connected to the first main surface of the frame portion and is convex toward the inside of the protrusion, a second curved surface that is convex toward the outside of the protrusion, and an inflection point located between the first curved surface and the second curved surface.

12. A package comprising: a light emitting element; a base supporting the light emitting element; and the lid member according to claim 1 or 2.

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