Cover for light-emitting element

Abstract

To secure smoothness of a reflection surface and accuracy of an angle even in mass production. To provide a cover for a light emitting element.SOLUTION: The cover 1 for the light emitting elements includes a transparent top plate part 11 and a frame part 21, and an inner surface of the frame part 21 has a reflecting surface 31aR for reflecting light emitted from the light emitting elements 1002 toward the top plate part 11. The first sidewall 31 of the frame part 21 has an inclined surface 31aR extending in the X direction parallel to the inner surface of the top plate part 11 and partially constituting the reflecting surface 31a, and two trapezoidal outer surfaces 31aR and 31c vertically connected to both ends of the inclined surface 31b in the X direction and constituting a part of the outer surfaces of the frame part 21. The composition of the main material of the second sidewall 42 and the third sidewall 43 of the frame portion 21 is different from the composition of the main material of the first sidewall 31, and the second sidewall 42 and the third sidewall 43 have joining end surfaces 31a and 43a fixed to both end portions of the inclined surface 42a in the X direction, and surfaces 31b and 31c disposed flush with the two trapezoidal outer surface 42b and 43b, respectively, to constitute a part of the outer surface of the frame portion 21.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cover for a light emitting element, and more particularly to a cover for a light emitting element having a reflective surface on its inner surface for reflecting light. [Background technology]

[0002] A known technique for preventing deterioration of light-emitting elements such as light-emitting diodes or laser diodes involves covering the light-emitting elements on a substrate with a cover and connecting the cover to the substrate to seal the light-emitting elements and maintain a dry environment inside. Such a light-emitting element cover is composed of a top plate and a frame with a rectangular cylindrical outer surface.

[0003] Light emitted from a light-emitting element on a substrate travels in the surface direction of the substrate. Therefore, in order to guide the light in a desired direction, a cover for a light-emitting element has been proposed, as disclosed in Patent Document 1, for example, in which a reflective surface inclined at 45° with respect to the top plate is provided on one of the four inner surfaces of the frame, thereby reflecting the light from the light-emitting element toward the top plate.

[0004] In Patent Document 1, the frame is made of silicon. In Figure 8 of Patent Document 1, a silicon single crystal plate is anisotropically etched to form multiple holes that will form the entire inner surface of the frame, and then the plate is cut to form multiple frame portions. More specifically, in order to obtain a surface with a 45° inclination angle that cannot be obtained by ordinary anisotropic etching of silicon single crystal, a silicon single crystal plate with a crystal orientation tilted by approximately 9.7° is produced, and this silicon single crystal plate is anisotropically etched. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2021-513226 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method of forming a frame using anisotropic etching according to Patent Document 1 is complicated, making it difficult to ensure the smoothness and angle precision of the reflective surface. Furthermore, the method of forming a frame using anisotropic etching according to Patent Document 1 is limited to frame materials made of single-crystal silicon, and cannot be applied to glass, which has an amorphous structure.

[0007] Another method for forming the frame is to hot-press a glass plate, form multiple holes that will form the entire inner surface of the frame, and then cut the plate to form multiple frames. However, if a stainless steel mold is used to ensure the smoothness of the reflective surface, the difference in thermal expansion coefficients between stainless steel and glass limits the number of holes that can be formed in one press, and if the number of holes is too large, the dimensional accuracy of the entire hole decreases. On the other hand, if a mold made of a material with a thermal expansion coefficient similar to that of glass is used, the smoothness of the reflective surface decreases compared to when a stainless steel mold is used. Therefore, if the entire inner surface of multiple frame sections is formed at once by hot-press molding, it is difficult to ensure the smoothness and angle accuracy of the reflective surface.

[0008] An object of the present invention is to provide a cover for a light-emitting element that can ensure the smoothness and angle precision of the reflective surface even when mass-produced. [Means for solving the problem]

[0009] (1) The cover for a light-emitting element of the present invention has the following configuration. A transparent top panel made primarily of glass; a frame portion having a rectangular cylindrical outer surface connected to the top plate portion, which is installed on the substrate so as to surround the light emitting element on the substrate, and which has a reflective surface on its inner surface that is inclined with respect to the top plate portion and that reflects light emitted from the light emitting element toward the top plate portion; A cover for a light-emitting element comprising: the frame portion has a first side wall, a second side wall, a third side wall, and a fourth side wall, each connected to the top plate portion; the first side wall has an inclined surface that is inclined with respect to the top plate portion, extends in an X direction parallel to an inner surface of the top plate portion that forms a space that accommodates the light emitting element, and a portion of the inclined surface constitutes the reflection surface; and two trapezoidal outer surfaces that are connected perpendicularly to both ends of the inclined surface in the X direction and constitute a portion of an outer surface of the frame portion, the second side wall has a joining end surface fixed to one end of the inclined surface of the first side wall in the X direction, and a trapezoidal outer surface that is disposed flush with one of the two trapezoidal outer surfaces of the first side wall and forms a part of the outer surface of the frame portion, the third side wall has a joining end surface fixed to the other end of the inclined surface of the first side wall in the X direction, and a trapezoidal outer surface that is disposed flush with the other of the two trapezoidal outer surfaces of the first side wall and forms a part of the outer surface of the frame portion, The fourth side wall is disposed opposite the first side wall and is connected to the second side wall and the third side wall.

[0010] According to this configuration, the second side wall and the third side wall are fixed to the first side wall. Therefore, when manufacturing a plurality of covers for light-emitting elements, for example, a first intermediate for forming a plurality of first side walls and a second intermediate for forming a plurality of second side walls and a plurality of third side walls are separately formed, bonded together, and then cut, thereby manufacturing a plurality of covers for light-emitting elements. Alternatively, for example, a first intermediate for forming a plurality of first side walls is formed in advance, and when a second intermediate for forming a plurality of second side walls and a plurality of third side walls is formed by hot press molding or the like, the second intermediate and the first intermediate are bonded together, and then cut, thereby manufacturing a plurality of covers for light-emitting elements. In either of the above two examples, after bonding the first intermediate and the second intermediate, a polishing process may be performed before cutting into a plurality of covers for light-emitting elements. In addition, the joining end surfaces of the second side wall and the third side wall are fixed to both ends in the X direction of the inclined surface of the first side wall, and the two trapezoidal outer surfaces perpendicular to the inclined surface of the first side wall form part of the outer surface of the frame portion. Therefore, when the above-mentioned first intermediate and second intermediate are fixed together, the multiple surfaces of the second intermediate that become the joining end surfaces of the multiple second side walls and the multiple third side walls can be fixed to a single flat surface that includes the multiple surfaces of the first intermediate that become the inclined surfaces of the multiple first side walls, lined up in a row in the X direction. This makes it easier to manufacture a cover for a light-emitting element with high smoothness and angle accuracy of the inclined surface of the first side wall in the cover for a light-emitting element, compared to when the entire inner surfaces of multiple frame portions are formed at once by hot press molding or etching, or when manufacturing a cover for a light-emitting element in a structure in which the inner surfaces of the second side wall and third side wall are fixed to two trapezoidal surfaces of the first side wall, and further makes it possible to suppress variation in these accuracy levels among multiple covers for a light-emitting element. In this way, the cover for a light-emitting element of the present invention can ensure the smoothness and angle precision of the reflective surface even when mass-produced. In the present invention, a top plate made mainly of glass may be a top plate made only of glass, or may be a top plate made of a base material made of glass and a layer other than glass covering at least a portion of the surface of the base material. In this specification, the term "main material" is used in the same sense as defined above. In the present invention, the phrase "the compositions of the main materials are different" not only refers to cases where the components contained in the main materials are different, but also includes cases where the components contained in the main materials are the same but the blending ratios are different. For example, even if two main materials are both glass, if the components contained therein or the blending ratios are different, the compositions of the main materials can be said to be different. In the present invention, the phrase "the second side wall has a joining end surface fixed to the inclined surface" means that the boundary between the first side wall and the second side wall can be confirmed visually, by microscopic observation, or by component analysis. For example, if the compositions of the main materials of the first side wall and the second side wall are different from each other, the joining end surface of the second side wall can be confirmed. Furthermore, even if the compositions of the main materials of the first side wall and the second side wall are the same, if the first side wall and the second side wall are joined with an adhesive having a different composition from the main materials of the first side wall and the second side wall, the joining end surface of the second side wall can be confirmed. The same applies to the joining end surface of the third side wall.

[0011] (2) The cover for a light-emitting element of the present invention may have the following configuration in addition to the configuration (1) above. The second side wall, the third side wall, and the fourth side wall have the same composition of main material, and the main material is glass or silicon.

[0012] According to this configuration, when manufacturing a plurality of covers for a light-emitting element, intermediate bodies for forming the plurality of second side walls, the plurality of third side walls, and the plurality of fourth side walls can be integrally molded. This makes it easier to form the frame portion so that the dimensional accuracy of the frame portion is high. Therefore, it is possible to provide covers for a light-emitting element that can be mass-produced more easily while ensuring the accuracy of the covers for a light-emitting element. When the second side wall, the third side wall, and the fourth side wall are mainly made of glass, intermediate bodies for forming the second side wall, the third side wall, and the fourth side wall can be integrally molded by hot press molding, thereby providing a light emitting element cover that can be mass-produced more easily while ensuring the precision of the light emitting element cover.

[0013] (3) The cover for a light-emitting element of the present invention may have the following configuration in addition to the configuration (1) or (2) above. the main material of the first side wall is glass, silicon, or ceramic; The reflecting surface is formed by a surface of a reflecting film provided on a surface of the first side wall made of the main material.

[0014] According to this configuration, the reflective surface is formed by the surface of the reflective film, so that even if the main material of the first side wall is glass, silicon or ceramic, it is possible to reflect the light emitted from the light emitting element with high reflectance. Furthermore, when the main material of the second side wall and the third side wall is glass or silicon and the main material of the first side wall is glass or silicon, the thermal expansion coefficient of the main material of the first side wall is close to or the same as the thermal expansion coefficient of the main material of the second side wall and the third side wall. Therefore, in this case, when manufacturing multiple light-emitting element covers, a first intermediate body for forming the multiple first side walls and a second intermediate body for forming the multiple second side walls and the multiple third side walls can be thermally bonded together while suppressing thermal distortion. This allows the light-emitting element covers to more reliably ensure the accuracy of the angle of the reflective surface, even when mass-produced.

[0015] (4) The cover for light-emitting element of the present invention may have the following configuration in addition to at least one of the configurations (1) to (3) above. The composition of the main material of the second sidewall and the composition of the main material of the third sidewall are different from the composition of the main material of the first sidewall.

[0016] According to this configuration, when manufacturing a plurality of covers for light-emitting elements, for example, a first intermediate body for forming the plurality of first side walls is formed in advance, and when a second intermediate body for forming the plurality of second side walls and the plurality of third side walls is formed by hot press molding, the second intermediate body and the first intermediate body can be fixed together. This makes it possible to provide covers for light-emitting elements that can be mass-produced more easily while ensuring the precision of the covers for light-emitting elements. [Effects of the Invention]

[0017] The cover for a light-emitting element of the present invention can ensure smoothness of the reflective surface and precision of the angle even when mass-produced. [Brief explanation of the drawings]

[0018] [Figure 1] 1A to 1C are diagrams illustrating an example of use of the light-emitting element cover according to the embodiment of the present invention. [Figure 2] 3A and 3B are diagrams illustrating the structure of a light-emitting element cover according to an embodiment of the present invention. [Figure 3] 5A to 5C are diagrams illustrating an example of a method for manufacturing a cover for a light-emitting element according to an embodiment of the present invention. [Figure 4] 10A to 10C are diagrams illustrating another example of a method for manufacturing a cover for a light-emitting element according to an embodiment of the present invention. [Figure 5] 10A to 10C are diagrams illustrating yet another example of the method for manufacturing the light-emitting element cover according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] A cover 1 for a light emitting element according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows an example of a usage mode of the light-emitting element cover 1. As shown in FIG. 1, the light-emitting element cover 1 is connected to the substrate 1001 while covering a light-emitting element 1002, such as a light-emitting diode or a laser diode, on the substrate 1001, thereby sealing the light-emitting element 1002 on the substrate 1001. The light-emitting element cover 1 includes a top plate portion 11 and a frame portion 21. The frame portion 21 is cylindrical and is installed on the substrate 1001 so as to surround the light-emitting element 1002 on the substrate 1001, and one opening of the frame portion 21 is closed by the substrate 1001. The top plate portion 11 is connected to the frame portion 21 so as to close the other opening of the frame portion 21. The inner surface of the frame portion 21 is inclined with respect to the top plate portion 11 and has a reflective surface 31aR for reflecting light emitted from the light-emitting element 1002 toward the top plate portion 11. The top plate portion 11 is transparent, and light emitted from the light-emitting element 1002 and reflected by the reflective surface 31aR passes through the top plate portion 11 and is emitted to the outside of the light-emitting element cover 1. Note that the use mode of the light-emitting element cover of the present invention (the size of the substrate 1001, the number of light-emitting elements 1002, etc.) is not limited to the mode shown in FIG.

[0020] Next, the configuration of the light-emitting element cover 1 will be described in detail. As shown in FIG. 2(a), the outer shape of the light-emitting element cover 1 is a rectangular parallelepiped. That is, the frame 21 has a rectangular cylindrical outer surface. The direction perpendicular to the top plate 11 is defined as the Y direction, and the directions perpendicular to two pairs of opposing surfaces of the rectangular cylindrical outer surface of the frame 21 that are perpendicular to each other are defined as the X direction and the Z direction, respectively. FIG. 2(b) is a cross-sectional view of the light-emitting element cover 1 cut along a plane perpendicular to the X direction and passing through the internal space of the frame 21. FIG. 2(c) is a cross-sectional view of the light-emitting element cover 1 cut along a plane perpendicular to the Z direction and passing through the internal space of the frame 21. FIG. 2(d) is a view of the light-emitting element cover 1 as viewed along the arrow X1 in FIG. 2(a). The ratios of the lengths of the light-emitting element cover 1 in the X, Y, and Z directions are not limited to those shown in FIG. 2. In FIG. 2, the length of the light-emitting element cover 1 in the X direction is the same as the length in the Z direction, but the length in the X direction may be longer or shorter than the length in the Y direction.

[0021] The top plate 11 is primarily made of glass. The top plate 11 may have an anti-reflection coating on at least one of the inner and outer surfaces, or may be made of glass alone. In this specification, glass refers to glass having an amorphous structure (non-crystalline structure). Examples of glass having an amorphous structure include borosilicate glass, quartz glass (silica glass), aluminosilicate glass, and multi-component optical glass. The glass used as the primary material of the top plate 11 has sufficient transparency to the wavelength of light emitted by the light emitting element 1002 (see FIG. 1). The surface of the top plate 11 that forms the space for accommodating the light emitting element 1002 (see FIG. 1) (hereinafter referred to as the inner surface) and the opposite surface (hereinafter referred to as the outer surface) are parallel to each other and perpendicular to the Y direction. The top plate 11 is transparent to allow light to pass through. The top plate 11 being transparent means that the top plate 11 is configured to suppress light scattering on its surface. The inner and outer surfaces of the top panel 11 have a high degree of smoothness to ensure transparency.

[0022] The frame 21 has a first side wall 31, a second side wall 42, a third side wall 43, and a fourth side wall 44, each connected to the top panel 11. The second side wall 42 and the third side wall 43 are connected to the first side wall 31. The fourth side wall 44 is disposed opposite the first side wall 31 and is connected to the second side wall 42 and the third side wall 43. The first side wall 31, the second side wall 42, the third side wall 43, and the fourth side wall 44 are fixed to a surface that is flush with the inner surface of the top panel 11.

[0023] The first side wall 31 is mainly made of glass, silicon, or ceramic. The first side wall 31 has an inclined surface 31a inclined relative to the top plate 11. The inclined surface 31a is a flat surface extending parallel to the X direction. The angle between the inclined surface 31a and the inner surface of the top plate 11 is 45°. A portion of the inclined surface 31a forms a reflective surface 31aR. The reflective surface 31aR is formed by the surface of a reflective film 22 provided on the surface of the first side wall 31 made of the main material. The reflective film 22 is formed on the entire inner surface of the frame 21. The reflective film 22 is a specular reflective film and is formed by a metal film or a dielectric multilayer film. The surface of the main material of the first side wall 31 covered with the reflective film 22 has a high smoothness to efficiently reflect light from the light emitting element 1002. As a result, the reflective surface 31aR formed by the surface of the reflective film 22 also has a high smoothness.

[0024] The first side wall 31 has a trapezoidal outer surface 31b that is perpendicularly connected to one end of the inclined surface 31a in the X direction and that forms part of the outer surface of the frame portion 21, and a trapezoidal outer surface 31c that is perpendicularly connected to the other end of the inclined surface 31a in the X direction and that forms part of the outer surface of the frame portion 21.

[0025] The composition of the main material of the first side wall 31 may be the same as or different from the composition of the main material of the top plate portion 11. The first side wall 31 and the top plate portion 11 may be directly bonded to each other by substrates made of the main material, or the substrates made of the main material may be bonded to each other via a bonding material (e.g., adhesive, brazing material, etc.). When the substrates made of the main material are directly bonded to each other, the bonding method may be, for example, laser bonding or thermal bonding. In this specification, laser bonding includes, for example, ultrashort pulse laser bonding. In this specification, when laser bonding substrates made of the main material are bonded to each other, the substrates are bonded by irradiating at least a portion of the contact surface where the substrates made of the main material come into contact with each other with a laser. In addition, in this specification, when thermally bonding substrates made of the main material are bonded to each other, at least one of the two substrates made of the main material melts, and the entire contact surface where the substrates made of the main material come into contact with each other is bonded. When the composition of the main material of the top panel 11 is the same as the composition of the main material of the first side wall 31, and the top panel 11 and the frame 21 are bonded to each other by laser welding between base materials made of the main material, the boundary between the top panel 11 and the first side wall 31 in the light-emitting element cover 1 can basically be confirmed by observation with a microscope. However, depending on conditions such as the laser output and the irradiation range, the boundary between the top panel 11 and the first side wall 31 may not be confirmed even with a microscope. When the composition of the main material of the top panel 11 is the same as the composition of the main material of the first side wall 31, and the top panel 11 and the frame 21 are bonded to each other by thermal welding between base materials made of the main material, the boundary between the top panel 11 and the first side wall 31 in the light-emitting element cover 1 can basically be confirmed even with a microscope.

[0026] The second side wall 42, the third side wall 43, and the fourth side wall 44 have the same composition of the main material. The second side wall 42, the third side wall 43, and the fourth side wall 44 are connected by base materials made of the main material. In other words, the second side wall 42, the third side wall 43, and the fourth side wall 44 have an integrated structure with no discernible boundary. The second side wall 42, the third side wall 43, and the fourth side wall 44 form a U-shaped body 41 that is U-shaped when viewed in the Y direction.

[0027] The main material of the U-shaped body 41 is glass or silicon. The composition of the main material of the U-shaped body 41 may be the same as or different from the composition of the main material of the top panel portion 11. The surfaces (hereinafter referred to as inner surfaces) of the second side wall 42, the third side wall 43, and the fourth side wall 44 that form the space for accommodating the light emitting element 1002 (see FIG. 1) are formed by the surface of the reflective film 22.

[0028] The composition of the main material of the U-shaped body 41 may be the same as or different from the composition of the main material of the first side wall 31. However, even if the compositions of the main materials of the U-shaped body 41 and the first side wall 31 are the same, in the cover 1 for light-emitting element, there are boundaries between the first side wall 31 and the second side wall 42 and between the first side wall 31 and the third side wall 43.

[0029] The second side wall 42 has a joining end surface 42a fixed to one end of the inclined surface 31a of the first side wall 31 in the X direction, and a trapezoidal outer surface 42b that is flush with the trapezoidal outer surface 31b of the first side wall 31 and forms part of the outer surface of the frame portion 21. The trapezoidal outer surface 42b is connected perpendicularly to the joining end surface 42a. The joining end surface 42a is the boundary surface with the first side wall 31. Similar to the second side wall 42, the third side wall 43 has a joining end surface 43a fixed to the other end of the inclined surface 31a of the first side wall 31 in the X direction, and a trapezoidal outer surface 43b that is flush with the trapezoidal outer surface 31c of the first side wall 31 and forms part of the outer surface of the frame portion 21. The trapezoidal outer surface 43b is connected perpendicularly to the joining end surface 43a. The joining end surface 43a is the boundary surface with the first side wall 31.

[0030] The second side wall 42 and the first side wall 31 may be directly bonded to each other by base materials made of the main material, or may be bonded to each other by a bonding material (e.g., adhesive, brazing material, etc.). When the base materials made of the main material are directly bonded to each other, the bonding method may be, for example, laser bonding or thermal bonding. As described above, even if the U-shaped body 41 and the first side wall 31 have the same composition of the main material, there are boundaries between the first side wall 31 and the second side wall 42 and between the first side wall 31 and the third side wall 43 in the light-emitting element cover 1. Therefore, when the base materials made of the main material of the second side wall 42 and the first side wall 31 are bonded to each other by thermal bonding, the compositions of the main materials of the U-shaped body 41 and the first side wall 31 are different from each other. Furthermore, when the base materials made of the main material of the second side wall 42 and the first side wall 31 are fixed to each other by laser joining, either the compositions of the main material of the U-shaped body 41 and the first side wall 31 are the same and the laser joining is performed under conditions that allow the boundary between the second side wall 42 and the first side wall 31 to be confirmed, or the compositions of the main material of the U-shaped body 41 and the first side wall 31 are different. Furthermore, when the base materials made of the main material of the second side wall 42 and the first side wall 31 are fixed to each other via a bonding material, either the compositions of the main material of the U-shaped body 41 and the first side wall 31 are the same and different from the composition of the bonding material, or the compositions of the main material of the U-shaped body 41 and the first side wall 31 are different. The method for fastening the third side wall 43 to the first side wall 31 is the same as the method for fastening the second side wall 42 to the first side wall 31 .

[0031] The method for fastening the U-shaped body 41 and the top plate 11 is the same as the method for fastening the first side wall 31 and the top plate 11. That is, the U-shaped body 41 and the top plate 11 may be directly fastened to each other by base materials made of a main material, or may be fastened to each other by a bonding material or the like. When the main materials of the top plate 11 and the U-shaped body 41 have the same composition, the boundary between the top plate 11 and the U-shaped body 41 may or may not be visible using a microscope depending on the fastening method between the top plate 11 and the frame 21, similar to the boundary between the top plate 11 and the first side wall 31 when the main materials of the top plate 11 and the first side wall 31 have the same composition.

[0032] The inner surfaces of the second side wall 42, the third side wall 43, and the fourth side wall 44 are slightly inclined with respect to the Y direction (the direction perpendicular to the top plate portion 11). This inclination is provided to facilitate demolding during hot press molding. Note that the inner surface of at least one of the second side wall 42, the third side wall 43, and the fourth side wall 44 may be perpendicular to the top plate portion 11. Furthermore, depending on the method for forming the U-shaped body 41, the inner surfaces of the second side wall 42, the third side wall 43, and the fourth side wall 44 may be inclined in the opposite direction to that in this embodiment.

[0033] Although not shown in the figures, the frame 21 has a conductive layer on the end surface opposite the top plate 11. The conductive layer is electrically connected to the substrate 1001. The thickness of the conductive layer may be constant or may vary depending on the position. The conductive layer may be formed in a ring shape, for example, across the end surfaces of the first side wall 31, the second side wall 42, the fourth side wall 44, and the third side wall 43. The frame 21 does not necessarily have to have a conductive layer.

[0034] Next, three specific examples of the manufacturing method of the light-emitting element cover 1 of this embodiment will be described. These three specific examples are manufacturing methods when the main material of the U-shaped body 41 is glass. Note that the manufacturing method of the light-emitting element cover 1 is not limited to these three specific examples. Rather than being limited to these three specific examples, multiple light-emitting element covers 1 can be manufactured simultaneously to improve production efficiency.

[0035] (Specific example of manufacturing method 1) First, a rectangular prism-shaped bar 40A is fabricated using glass, the main material of the U-shaped body 41, by hot press molding and cutting, with multiple, roughly square pyramidal holes 45 arranged in a row, as shown in FIG. 3(a). A portion of the inner surface of one hole 45 will ultimately become the inner surfaces of the second side wall 42, the third side wall 43, and the fourth side wall 44 of one U-shaped body 41. Next, as shown in FIG. 3(b), the corners of this bar 40A are flat-polished to form 45° inclined surfaces. Portions of these polished surfaces will ultimately become the joining end surfaces 42a of the multiple second side walls 42 and the joining end surfaces 43a of the multiple third side walls 43. Next, a thin plate-shaped bar 30A, as shown in FIG. 3(c), is prepared. The bar 30A is formed from the main material of the first side wall 31, which is glass, silicon, or ceramic, and one surface 30Aa of the bar 30A has been previously smoothed to enhance smoothness. Then, as shown in FIG. 3(c), the smoothed surface 30Aa of the bar 30A and the polished surface of the bar 40A are joined to obtain the joined body 20A. The joining method in this joining process may be, for example, thermal joining, laser joining, or joining using a bonding material. A portion of the smoothed surface 30Aa of the bar 30A will ultimately become the inclined surfaces 31a of the multiple first side walls 31. That is, through this joining process, the surfaces that will become the joining end surfaces 42a of the multiple second side walls 42 and the joining end surfaces 43a of the multiple third side walls 43, which are included in the polished surface of the bar 40A, are fixed to a single smoothed surface 30Aa, which includes multiple surfaces that will become the inclined surfaces 31a of the multiple first side walls 31, arranged in a line. Next, as shown in FIG. 3(d), both sides and at least one side of the joined body 20A are flat-polished.

[0036] Although not shown in the figure, a reflective film 22 (see FIG. 2) is then formed on the entire surface of one side of the joined body 20A (the surface on the smoothed surface 30Aa side), and the reflective film 22 is then removed from the end surface of the joined body 20A by flat polishing. A conductive layer (not shown) is also formed on the opposite end surface of the joined body 20A. Then, flat plates that will become multiple top panel portions 11 are bonded to the end surface of the joined body 20A from which the reflective film 22 has been removed. The bonding method used here is preferably, for example, ultrashort pulse laser bonding or bonding with an adhesive, in order to reduce the thermal influence on the conductive layer. If no conductive layer is provided, the flat plates that will become the top panel portions 11 and the joined body 20A may be thermally bonded. After bonding, a cutting process is performed to produce multiple light-emitting element covers 1. During this cutting process, a surface including the trapezoidal outer surface 31b of the first side wall 31 and the trapezoidal outer surface 42b of the second side wall 42, and a surface including the trapezoidal outer surface 31c of the first side wall 31 and the trapezoidal outer surface 43b of the third side wall 43 are formed.

[0037] (Specific example of manufacturing method 2) First, a mold 50 for hot press molding, as shown in FIG. 4(a), is prepared. The mold 50 has multiple protrusions 51 arranged in a grid pattern. Each protrusion 51 is a rectangular column tapered toward its tip, with a V-groove with a 90° opening angle formed at its tip. As shown in FIG. 4(b), bars 30B with right-angled triangular cross sections are placed along the V-grooves of the protrusions 51 in each row. The bars 30B are made of glass, silicon, or ceramic, which is the main material of the first side wall 31. Two surfaces 30Ba, 30Ba of the bars 30B that contact the V-grooves of the protrusions 51 are previously smoothed to enhance smoothness. A portion of one smoothed surface 30Ba will eventually become the inclined surfaces 31a of the multiple first side walls 31. Next, as shown in FIGS. 4(c) and 4(d), the multiple bars 30B and multiple protrusions 51 are pressed against a glass plate 40, the main material of the U-shaped body 41, and hot press molding is performed to obtain a plate 40B. In the manufacturing method of Example 2, when the main material of the first side wall 31 is glass or silicon, glass or silicon with a higher softening temperature than the glass main material of the U-shaped body 41 is used. This allows the bar 30B and the plate 40B to be thermally bonded while maintaining the smoothness of the smoothed surface 30Ba of the bar 30B during hot press molding. After hot press molding, the mold 50 is removed from the plate 40B as shown in FIG. 4(e). Multiple holes 46 are formed in the plate 40B by the multiple protrusions 51. A portion of the inner surface of one hole 46 will eventually become the inner surfaces of the second side wall 42, the third side wall 43, and the fourth side wall 44 of the two U-shaped bodies 41. Portions of the bar 30B are positioned at the bottoms of the multiple holes 46, and other portions are embedded in the plate 40B. During hot press molding, a surface is formed on the plate 40B that adheres to the smoothed surface 30Ba of the embedded portion of the bar 30B. Parts of this surface will ultimately become the joining end surface 42a of the second side wall 42 and the joining end surface 43a of the third side wall 43. In other words, during the heat press molding, surfaces that will become the joining end surfaces 42a of the plurality of second side walls 42 and the joining end surfaces 43a of the plurality of third side walls 43 are formed on one smoothed surface 30Ba, which includes a plurality of surfaces that will become the inclined surfaces 31a of the plurality of first side walls 31 lined up in a row, and are fixed to the smoothed surface 30Ba by thermal bonding.

[0038] Although not shown, both surfaces of the bonded body 20B obtained by the heat press molding are then polished. Next, a reflective film 22 (see FIG. 2) is formed on the entire surface of one side of the bonded body 20B (the surface on the smoothed surface 30Ba side), and then the reflective film 22 is removed from the end surface of the bonded body 20B by polishing. A conductive layer (not shown) is also formed on the opposite end surface of the bonded body 20B. Then, flat plates that will become multiple top panel portions 11 are bonded to the end surface of the bonded body 20B from which the reflective film 22 has been removed. The bonding method is the same as in Example 1. After bonding, a cutting process is performed to manufacture multiple light-emitting element covers 1. During this cutting process, the rectangular cylindrical outer surface of the frame portion 21 is formed. In the cross-sectional view and plan view included in FIG. 4(e), the dashed-double-dot rectangle indicates the outer shape of the frame portion 21.

[0039] (Specific example of manufacturing method 3) As shown in FIG. 5(a), a plate 40B is hot-press molded using the same procedure as in Example 2 of the manufacturing method described above, except that a forming bar 60 is used instead of the bar 30B in Example 2. Two surfaces 60a, 60a of the forming bar 60 that contact the V-groove of the protrusion 51 are previously smoothed to enhance smoothness. FIG. 5(a) shows the state immediately after the mold 50 is removed. After demolding, as shown in FIG. 5(b), the surface of the plate 40B opposite the opening side of the hole 46 is polished until the forming bar 60 is exposed. Then, as shown in FIG. 5(c), the forming bar 60 is removed from the plate 40B. A V-groove is formed in the plate 40B by the forming bar 60. Next, as shown in FIG. 5(d), a bar 30C made of glass, silicon, or ceramic, the main material of the first side wall 31, is placed along the V-groove of the plate 40B, and the plate 40B and the bar 30C are joined to obtain a joined body 20C. The joining method in this joining process may be, for example, thermal joining or joining using a bonding material. The two surfaces 30Ca, 30Ca of the bar 30C that contact the V-groove of the plate 40B are previously smoothed to enhance smoothness. A portion of one smoothed surface 30Ca will ultimately become the inclined surfaces 31a of the multiple first side walls 31. In other words, this joining process fixes the surfaces of the plate 40B that will become the joining end surfaces 42a of the multiple second side walls 42 and the joining end surfaces 43a of the multiple third side walls 43 to the single smoothed surface 30Ca, which includes the multiple surfaces that will become the inclined surfaces 31a of the multiple first side walls 31, aligned in a row. Because the smoothed surface 30Ca of the bar 30C is joined to the surface formed by the smoothed surface 60a of the plate 40B, the bar 30C can be joined to the plate 40B with high precision.

[0040] Although not shown in the figure, both surfaces of the resulting bonded body 20C are then polished to a flat surface. Thereafter, a plurality of covers 1 for light-emitting elements are manufactured using the same procedure as in Example 2. In the cross-sectional view and plan view included in FIG. 5(d), the rectangle with two-dot chain lines indicates the outline of the frame portion 21.

[0041] In addition, when the main material of the U-shaped body 41 is silicon, for example, a silicon bar having a shape similar to the bar 40A shown in Figure 3(a) can be formed by etching and cutting, and then multiple covers 1 for light-emitting elements can be manufactured using the same procedure as in Example 1.

[0042] The cover 1 for light-emitting element of this embodiment has the following technical effects.

[0043] In order to allow the light emitted from the light emitting element 1002 to exit from the light emitting element cover 1 in a desired direction, the accuracy of the smoothness of the reflecting surface 31aR and the accuracy of the angle of the reflecting surface 31aR are important. In the cover 1 for light-emitting element of this embodiment, the second side wall 42 and the third side wall 43 are fixed to the first side wall 31. Therefore, when manufacturing a plurality of covers 1 for light-emitting elements, for example, a first intermediate body (e.g., bars 30A and 30C in specific examples 1 and 3) for forming the plurality of first side walls 31 and a second intermediate body (e.g., bar 40A in specific example 1 or plate 40B in specific example 3) for forming the plurality of second side walls 42 and the plurality of third side walls 43 are separately formed, bonded together, and then cut, thereby manufacturing a plurality of covers 1 for light-emitting elements. Also, for example, a first intermediate body (e.g., bar 30B in specific example 2) for forming the plurality of first side walls 31 is formed in advance, and when a second intermediate body (e.g., plate 40B in specific example 2) for forming the plurality of second side walls 42 and the plurality of third side walls 43 is formed by hot press molding or the like, the second intermediate body and the first intermediate body are bonded together and then cut, thereby manufacturing a plurality of covers 1 for light-emitting elements. In addition, in the cover 1 for the light-emitting element of this embodiment, the joining end surface 42a of the second side wall 42 and the joining end surface 43a of the third side wall 43 are fixed to both ends in the X direction of the inclined surface 31a of the first side wall 31, and the two trapezoidal outer surfaces 31b, 31c perpendicular to the inclined surface 31a of the first side wall 31 form part of the outer surface of the frame portion 21. Therefore, when the above-mentioned first intermediate and second intermediate are fixed together, the multiple surfaces of the second intermediate, which become the joining end surfaces 42a of the multiple second side walls 42 and the joining end surfaces 43a of the multiple third side walls 43, can be fixed to a single flat surface (for example, the smoothed surfaces 30Aa, 30Ba, 30Ca in specific examples 1 to 3) that includes the multiple surfaces of the first intermediate, which become the inclined surfaces 31a of the multiple first side walls 31, lined up in a row in the X direction. This makes it easier to manufacture the cover for light-emitting element 1 so that the smoothness and angle precision of the inclined surface 31a of the first side wall 31 in the cover for light-emitting element 1 are high, compared to when the entire inner surfaces of multiple frame portions 21 are formed at once by hot press molding or etching, or when manufacturing a cover for light-emitting element having a structure in which the inner surfaces of the second side wall 42 and the third side wall 43 are fixed to two trapezoidal surfaces of the first side wall 31, and further makes it possible to suppress variation in these precisions between multiple covers for light-emitting element 1. In this way, even when the light-emitting element cover 1 is mass-produced, it is possible to ensure the smoothness and angle precision of the reflecting surface 31aR.

[0044] Since the second side wall 42, the third side wall 43, and the fourth side wall 44 have the same composition as each other as the main material, when manufacturing a plurality of covers for light-emitting element 1, an intermediate body (for example, bar 40A in specific example 1, plate 40B in specific examples 2 and 3) for forming the plurality of second side walls 42, the plurality of third side walls 43, and the plurality of fourth side walls 44 can be integrally molded. This makes it easy to form frame portion 21 so that the dimensional accuracy of frame portion 21 is high. Therefore, it is possible to provide covers for light-emitting element 1 that can be mass-produced more easily while ensuring the accuracy of the covers for light-emitting element 1. Furthermore, when the main material of the second side wall 42, the third side wall 43, and the fourth side wall 44 is glass, an intermediate body for forming the plurality of second side walls 42, the plurality of third side walls 43, and the plurality of fourth side walls 44 can be integrally molded by hot press molding. Therefore, it is possible to provide a light-emitting element cover 1 that can be mass-produced more easily while ensuring the precision of the light-emitting element cover 1.

[0045] Since the reflecting surface 31aR is formed by the surface of the reflecting film 22, even if the main material of the first side wall 31 is glass, silicon, or ceramic, the light emitted from the light emitting element 1002 can be reflected with high reflectance. Furthermore, since the main material of the second side wall 42 and the third side wall 43 is glass or silicon, when the main material of the first side wall 31 is glass or silicon, the thermal expansion coefficient of the main material of the first side wall 31 is close to or the same as the thermal expansion coefficient of the main material of the second side wall 42 and the third side wall 43. Therefore, when manufacturing a plurality of light-emitting element covers 1, a first intermediate body for forming the plurality of first side walls 31 (e.g., bars 30A, 30B, and 30C in Examples 1 to 3) and a second intermediate body for forming the plurality of second side walls 42 and the third side wall 43 (e.g., bar 40A in Example 1 and plate 40B in Examples 2 and 3) can be thermally bonded together while suppressing thermal distortion. This allows the light-emitting element covers 1 to more reliably ensure the accuracy of the angle of the reflective surface 31aR, even when mass-produced.

[0046] Although the preferred embodiment of the present invention has been described above, the present invention can be modified in various ways within the scope of the claims.

[0047] In the above embodiment, the angle formed between the inclined surface 31a of the first side wall 31 and the inner surface of the top plate portion 11 is 45°, but depending on the application of the light-emitting element cover of the present invention, the angle formed between the inclined surface of the first side wall and the inner surface of the top plate portion may be greater or smaller than 45°.

[0048] In the above embodiment, the reflective film 22 is formed on the entire inner surface of the frame portion 21. However, in the present invention, the reflective film may be formed only on a portion of the inner surface of the frame portion. For example, the reflective film may be formed only on the inclined surface of the first side wall. In this case, the reflective film may be formed on the entire region of the inclined surface that is not fixed to the joining end surface, or may be formed only on a portion of the region of the inclined surface that is not fixed to the joining end surface.

[0049] In the present invention, when the main material of the first side wall is silicon, the reflective film may not be provided, and the silicon surface may be used as a reflective surface for reflecting the light emitted from the light emitting element.

[0050] In the manufacturing methods of the above embodiments, the intermediates (bar 40A in the first embodiment and plate 40B in the second and third embodiments) for forming the second, third, and fourth side walls 42, 43, and 44 are integrally molded. However, in the light-emitting element cover of the present invention, if the main materials of the second, third, and fourth side walls have the same composition, the intermediates for forming the second, third, and fourth side walls do not have to be integrally molded when manufacturing the light-emitting element cover. For example, the intermediates for forming the second and third side walls and the intermediates for forming the fourth side walls may be formed separately and then bonded together.

[0051] In the present invention, the compositions of the main materials of the second side wall, the third side wall, and the fourth side wall do not have to be the same. For example, the compositions of the main materials of the second side wall and the third side wall may be the same but different from the composition of the main material of the fourth side wall. Alternatively, the compositions of the main materials of the second side wall and the third side wall may be different from each other, and the composition of the main material of the second side wall or the third side wall may be the same as the composition of the main material of the fourth side wall. When the compositions of the main materials of the second side wall, the third side wall, and the fourth side wall are not the same, the main materials of the second side wall, the third side wall, and the fourth side wall may all be glass or a combination of glass and silicon.

[0052] The manufacturing method of the above-mentioned specific example 1 can also be applied when the bar 30A and the bar 40A have the same main material composition and are thermally bonded to each other. The manufacturing method of the above-mentioned specific example 2 can also be applied when the bar 30B and the plate 40B have the same main material composition. The manufacturing method of the above-mentioned specific example 3 can also be applied when the bar 30C and the plate 40B have the same main material composition and are thermally bonded to each other. However, in the light-emitting element covers manufactured by these methods, the boundaries between the first and second side walls and the boundaries between the first and third side walls cannot be confirmed even with a microscope, and therefore, these covers are not included in the light-emitting element covers of the present invention. [Explanation of symbols]

[0053] 1: cover for light-emitting element, 11: top plate portion, 21: frame portion, 22: reflective film, 31: first side wall, 31a: inclined surface, 31aR: reflective surface, 31b, 31c: trapezoidal outer surface, 41: U-shaped body, 42: second side wall, 43: third side wall, 44: fourth side wall, 42a, 43a: bonding end surface, 42b, 43b: trapezoidal outer surface, 1001: substrate, 1002: light-emitting element

Claims

1. A transparent top panel made primarily of glass; a frame portion having a rectangular cylindrical outer surface connected to the top plate portion, which is installed on the substrate so as to surround the light emitting element on the substrate, and which has a reflective surface on its inner surface that is inclined with respect to the top plate portion and that reflects light emitted from the light emitting element toward the top plate portion; A cover for a light-emitting element comprising: the frame portion has a first side wall, a second side wall, a third side wall, and a fourth side wall, each connected to the top plate portion; the first side wall has an inclined surface that is inclined with respect to the top plate portion, extends in an X direction parallel to an inner surface of the top plate portion that forms a space that accommodates the light-emitting element, and a portion of the inclined surface constitutes the reflection surface; and two trapezoidal outer surfaces that are connected perpendicularly to both ends of the inclined surface in the X direction and constitute a portion of an outer surface of the frame portion, the second side wall has a joining end surface fixed to one end of the inclined surface of the first side wall in the X direction, and a trapezoidal outer surface that is disposed flush with one of the two trapezoidal outer surfaces of the first side wall and forms a part of the outer surface of the frame portion, the third side wall has a joining end surface fixed to the other end of the inclined surface of the first side wall in the X direction, and a trapezoidal outer surface that is disposed flush with the other of the two trapezoidal outer surfaces of the first side wall and forms a part of the outer surface of the frame portion, The cover for a light-emitting element, wherein the fourth side wall is disposed opposite the first side wall and is connected to the second side wall and the third side wall.

2. The cover for a light emitting device according to claim 1 , wherein the second side wall, the third side wall, and the fourth side wall have the same main material composition, and the main material is glass or silicon.

3. a main material of the first side wall is glass, silicon, or ceramic; 3. The light-emitting element cover according to claim 1, wherein the reflective surface is formed by a surface of a reflective film provided on a surface of the first side wall made of a main material.

4. The cover for a light-emitting element according to claim 1 , wherein the composition of the main material of the second side wall and the composition of the main material of the third side wall are different from the composition of the main material of the first side wall.

Images