Light-emitting device and method for manufacturing a light-emitting device

Abstract

This invention provides a light-emitting device in which a light-emitting element is hermetically sealed using a glass material that readily contains voids, such as glass frit. [Solution] The light-emitting device according to the present invention hermetically bonds a light-transmitting member that covers the space on a package substrate in which a light-emitting element is arranged and transmits light emitted by the light-emitting element, to the upper surface of the package substrate with a bonding layer. The bonding layer is made of glass. The upper surface of the package substrate is provided with a first bonding layer that surrounds the area around where the light-emitting element is arranged in a frame shape of a predetermined width, a groove that surrounds the outside of the first area, and a second bonding layer that surrounds the outside of the groove in a frame shape of a predetermined width. The bonding layer is arranged in the area sandwiched between the first bonding layer and the lower surface of the light-transmitting member, and in the area sandwiched between the second bonding layer and the lower surface of the light-transmitting member, and a space that is not filled by the bonding layer is provided in at least the area in contact with the bottom surface of the groove.

Description

Technical Field

[0001] The present invention relates to a light-emitting device in which a light-emitting device is hermetically sealed.

Background Art

[0002] In order to hermetically seal light-emitting elements and electronic components, packages are known in which these are mounted on a substrate, covered with a lid member, and the periphery of the substrate and the lid member is hermetically sealed with a brazing material or the like.

[0003] For example, Patent Document 1 discloses a structure in which a semiconductor chip is mounted on a package body and the periphery of the package body and the lid member is sealed with solder. A groove-shaped depression is provided in the substrate of the sealing portion, solder balls are arranged inside the depression, and by melting the solder balls, the depression is filled with solder while being joined to the lid member.

[0004] Patent Document 2 discloses a structure in which a crystal oscillator is mounted on a substrate, covered with a lid member, and the periphery of the substrate and the lid member is sealed with glass. At this time, a groove is provided around the substrate, the glass flows into the groove, and a fillet is formed around the glass to cause an anchor effect in the glass in the groove.

[0005] Patent Document 3 discloses a structure in which a metallized layer, which is a gold electrode, is formed on the upper surface of a ceramic substrate, and the upper surface of the ceramic substrate and the lid member are sealed with a glass sealing material attached to the periphery of the lower surface of the lid member. A groove is provided around the substrate, and a ceramic layer is arranged on the upper surface of the metallized layer so that the inner wall and the periphery of the groove can be joined by the glass sealing material. The glass sealing material is melted at a low temperature of 380°C to 420°C, fills the inside of the groove, and has a large horizontal adhesive strength.

[0006] Patent Document 4 discloses a structure in which the periphery of a substrate on which a piezoelectric vibrator is mounted and the periphery of a lid member are sealed with low-melting-point glass or a eutectic alloy. Grooves are provided in the sealing portions of the substrate and the lid member so as to face each other, and the low-melting-point glass or eutectic alloy fills the opposing grooves. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2021-150348 [Patent Document 2] Japanese Patent Publication No. 2013-98594 [Patent Document 3] Japanese Utility Model Publication No. 1-171036 [Patent Document 4] Japanese Patent Publication No. 2001-9374 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] As described in Patent Document 1, when solder is used as a bonding material to seal the substrate and the lid member, it is necessary to form a metallized layer at the joint, which complicates the manufacturing process.

[0009] On the other hand, as described in Patent Documents 2 to 4, when glass is used as a bonding material to seal the substrate and the lid member, a metallization layer is unnecessary. However, when attempting to melt glass to form a thin, desired shape, it is easy to incorporate air bubbles, making it difficult to form an airtight sealing portion.

[0010] Specifically, by using a glass paste containing glass frit to form the glass joint, the joint can be formed through a printing process and a heating process, thus simplifying the process. However, joints formed by heating glass frit tend to contain air bubbles, especially between the glass frit particles, and if these bubbles are continuous, airtightness cannot be maintained.

[0011] The structures disclosed in Patent Documents 2 to 4 aim to improve bonding strength by completely filling the grooves with glass, thereby creating an anchoring effect from the glass filling the grooves. However, they do not take into account air bubbles that are easily contained in glass. When attempting to completely fill the grooves with glass, there is no escape route for air bubbles, making it difficult to reduce the amount of air bubbles contained in the glass. Furthermore, if there is too much glass, the joint will protrude both inside and outside the sealing portion, resulting in defects.

[0012] The object of the present invention is to provide a light-emitting device that seals a light-emitting element simply and airtightly, using a glass material that easily contains voids such as glass frit. [Means for solving the problem]

[0013] A light-emitting device according to one aspect of the present disclosure includes a package substrate, a light-emitting element mounted in a predetermined mounting area on the upper surface of the package substrate, a light-transmitting member covering the area on the package substrate where the light-emitting element is mounted and transmitting light emitted by the light-emitting element, and a bonding layer that joins the upper surface of the package substrate and the lower surface of the light-transmitting member around the mounting area of ​​the package substrate, hermetically sealing the space around the light-emitting element. The bonding layer is made of glass. The bonding layer is arranged to surround the mounting area with a predetermined width. A groove narrower than the bonding layer is provided in the portion of the upper surface of the package substrate where the bonding layer is located, so as to surround the mounting area. The bonding layer includes a first bonding layer that surrounds the mounting area on the side closer to the mounting area than the groove, and a second bonding layer that surrounds the mounting area on the side further from the mounting area than the groove. The bonding layer is not in contact with the bottom surface of the groove.

[0014] A method for manufacturing a light-emitting device according to one aspect of this disclosure is: A glass paste layer formation step involves forming a frame-shaped glass paste layer of a predetermined width on the underside of a light-transmitting member that transmits light of a predetermined wavelength using a glass paste containing glass frit and a solvent; a calcination step involves calcining the glass paste layer printed on the light-transmitting member to remove the solvent and create an unmelted glass frit layer; A package substrate preparation step is to prepare a package substrate in which a light-emitting element is mounted on a mounting area on the upper surface, wherein a groove with a frame shape corresponding to the frame shape of the glass frit layer and narrower than the glass frit layer is formed around the mounting area at a position corresponding to the center in the width direction of the glass frit layer, The mounting process involves mounting the light-transmitting member so that the glass frit layer overlaps with the groove on the upper surface of the package substrate. The method includes a bonding layer formation step in which a glass frit layer is heated and melted to form a first bonding layer surrounding the mounting area on the side closer to the mounting area than the groove, and a second bonding layer surrounding the mounting area on the side further away from the mounting area than the groove, and the first bonding layer and the second bonding layer are used to bond the upper surface of the package substrate and the lower surface of the light-transmitting member, and the molten glass frit layer is not brought into contact with the bottom surface of the groove, thereby forming a space within the groove. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a light-emitting device in which a light-emitting element is hermetically sealed while using a glass material that easily contains voids such as glass frit. [Brief explanation of the drawing]

[0016] [Figure 1] (a) is a cross-sectional view of the light-emitting device 1 according to an embodiment of the present invention, (b) is an enlarged view of Figure 1(a), and (c) and (d) are a top view and a cross-sectional view of the package substrate of the light-emitting device 1. [Figure 2] (a) to (e) are explanatory diagrams showing the manufacturing process of the light-emitting device 1 of the embodiment. [Figure 3] (a) and (b) are diagrams illustrating the movement of voids in the molten first bonding layer 26 and second bonding layer 27 during the manufacturing process of the light-emitting device 1 of the embodiment. [Figure 4] (a) is a cross-sectional view showing a void in the first bonding layer 26 or the second bonding layer 27 of the light-emitting device 1, and (b) is a cross-sectional view showing a void in the bonding layer of a light-emitting device without the groove 28 of the comparative example. [Modes for carrying out the invention]

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the scope of the present invention is not limited to the embodiment described here, and various modifications can be made without departing from the spirit of the present invention.

[0018] FIG. 1(a) is a cross-sectional view of the light-emitting device 1 of the present invention, and FIG. 1(b) is a partially enlarged view thereof. FIGS. 1(c) and (d) are top views and cross-sectional views of the package substrate of the light-emitting device 1.

[0019] As shown in FIG. 1(a), the light-emitting device 1 of the present invention includes a package substrate 20, a light-emitting element 10 mounted in a predetermined mounting region 21 on the upper surface of the package substrate 20, a light-transmissive member 30, and a bonding layer 40.

[0020] In this embodiment, the light-emitting element 10 emits deep ultraviolet light (wavelength 100 to 280 nm).

[0021] As shown in FIGS. 1(a) and (c), the package substrate 20 has a recess 25 for arranging the light-emitting element 10. The mounting region 21 of the light-emitting element 10 is provided on the bottom surface of the recess. A pair of electrodes 22, 23 are arranged in the mounting region 21. The light-emitting element 10 is mounted on the electrodes 22, 23, and a pair of element electrodes (not shown) on the lower surface of the light-emitting element 10 are respectively bonded.

[0022] In this embodiment, the package substrate 20 is made of Si and its surface is covered with a thermal oxide film 24. The material of the package substrate 20 is not limited to Si and may be composed of other materials. For example, a package substrate 20 made of any one of Si, LTCC (Low Temperature Co-fired Ceramics), Al2O3, and AlN, or a composite material of two or more of these can be used.

[0023] The light-transmitting member 30 is made of a material that transmits light emitted by the light-emitting element 10. The light-transmitting member 30 covers the space of the recess 25 where the light-emitting element 10 is located, and transmits the light (deep ultraviolet light) emitted by the light-emitting element 10 upwards. As the material of the light-transmitting member 30, for example, borosilicate glass, synthetic quartz glass, and quartz glass can be used.

[0024] The recess 25 of the package substrate 20 does not necessarily have to be formed, and may be flat. When a flat package substrate 20 is used, a dome-shaped or the like can be used as the light-transmitting member 30 to cover the light-emitting element 10 in the mounting area 21.

[0025] A band-shaped bonding layer 40 of a predetermined width is arranged on the upper surface surrounding the mounting area 21 of the package substrate 20, joining the upper surface of the package substrate 20 to the lower surface of the light-transmitting member 30. In the structure shown in Figures 1(a) to (c), a recess 25 is formed in the package substrate 20, so the area around the mounting area 21 forms a terrace (edge) 22a that is one step higher than the bottom surface of the recess 25. The bonding layer 40 hermetically joins the upper surface of the terrace 22a of the package substrate 20 to the lower surface of the light-transmitting member 30. As a result, the bonding layer 40 hermetically seals the space around the light-emitting element 10 to the outside.

[0026] The bonding layer 40 is made of glass. Specifically, the bonding layer 40 is made of multiple glass particles (glass frit) that are welded together.

[0027] The glass constituting the bonding layer 40 is preferably made of a material that does not degrade due to light emitted by the light-emitting element 10. However, in configurations such as Figure 1(a), where light from the light-emitting element 10 is blocked by the side walls of the recess 25 and does not easily reach the bonding layer 40, it is possible to use a material that degrades due to light from the light-emitting element 10 as the material constituting the bonding layer 40. Specifically, as the material constituting the bonding layer 40, for example, any of V2O5·ZnO, V2O5·TeO2, Bi2O3·ZnO, borosilicate glass, synthetic quartz glass, and quartz glass can be used.

[0028] As shown in Figure 1(c), a groove 28 narrower than the bonding layer 40 is provided on the upper surface of the package substrate 20 in the area where the bonding layer 40 on the upper surface of the package substrate 20 is located. As a result, the bonding layer 40 includes a first bonding layer 26 that surrounds the mounting area 21 on the side closer to the mounting area than the groove 28 and bonds the upper surface of the package substrate 20 to the lower surface of the light-transmitting member 30, and a second bonding layer 27 that surrounds the mounting area on the side further from the mounting area 21 than the groove 28 and bonds the upper surface of the package substrate 20 to the lower surface of the light-transmitting member 30.

[0029] The first bonding layer 26 prevents leakage, achieves hermetic sealing, and generates bonding strength. On the other hand, the second bonding layer 27 increases the bonding area of ​​the bonding layer 40 and enhances the bonding strength. For example, the width of the first bonding layer 26 can be set to the same width as the width of the second bonding layer 27.

[0030] There is a space at the bottom of the groove 28 that is not in contact with the bonding layer 40. Therefore, at least the portion of the space within the groove 28 that is in contact with the bottom surface is a space that is not filled with the bonding layer 40. To produce a good yield, it is better to manufacture the bonding layer 40 so that it does not come into contact with the entire bottom surface of the groove 28. However, since it is sufficient to provide a space within the groove 28 for the gas present between the glass frit particles to move, as described later, it is acceptable for the bonding layer 40 that has dripped down to come into contact with a part of the bottom surface of the groove 28, and for the remaining bottom surface to be a space where the bonding layer 40 does not come into contact with it. This makes it possible to secure a space within the groove 28 for the gas to move. In other words, if there is a space in the groove 28 where the bonding layer 40 does not come into contact with the bottom surface, it is possible to reduce voids.

[0031] In order to prevent the bonding layer 40 from coming into contact with the bottom surface of the groove 28, it is preferable that the depth of the groove 28 be greater than or equal to the thickness of the bonding layer 40.

[0032] For example, the thickness of the frit glass paste layer for forming the bonding layer 40 is set to 2 to 15 μm. This is because if the thickness of the frit glass paste layer is less than 2 μm, bonding between the package substrate 2 and the light-transmitting member 30 by the bonding layer 40 becomes difficult, and if the thickness is greater than 15 μm, film formation by printing becomes difficult.

[0033] For example, the depth of the groove 28 is set to 10 to 200 μm. If the groove 28 is shallower than 10 μm, it is difficult to form the groove 28, and if it is deeper than 200 μm, it may reduce the strength of the package substrate 20.

[0034] It is desirable to set the width of the first bonding layer 26 to be greater than or equal to the width of the groove 28.

[0035] For example, the width of the groove 28 is set to be between 10 μm and 100 μm. If the width of the groove 28 is less than 10 μm, it is difficult to form the groove 28, and if the width of the groove 28 is greater than 100 μm, the widths of the first bonding layer 26 and the second bonding layer 27 become narrower, reducing the bonding area, which makes it difficult to achieve airtightness and maintain bonding strength.

[0036] Voids contained within the first bonding layer 26 will leak if they connect to each other continuously in the width direction of the first bonding layer 26. If the width of the first bonding layer 26 is too narrow, the probability that a few voids will continuously leak in the width direction of the first bonding layer 26 increases. Also, if the width of the first bonding layer 26 is too narrow, the bonding area will be small and it will be impossible to ensure sufficient bonding strength. Therefore, from the viewpoint of preventing leaks and ensuring bonding strength, it is necessary to ensure a certain width for the first bonding layer 26. On the other hand, since the second bonding layer 27 is a layer that increases the bonding strength of the bonding layer 40, its bonding area may be even larger than that of the first bonding layer 26.

[0037] As described above, the width of the groove 28 is 10 to 100 μm and the depth of the groove 28 is 10 to 200 μm, so the width / depth ratio is approximately 1 to 2. Furthermore, the relationship between the width of the surface of the terrace 22a to which the bonding layer 40 is adhered and the width of the groove 28 is preferably set to between 100 μm when the width of the adhered surface is 150 μm and 10 μm when the width of the adhered surface is 240 μm. Therefore, the ratio between the width of the surface of the terrace 22a to which the bonding layer 40 is adhered and the width of the groove 28 is approximately 1.5 to 24.

[0038] As described above, the light-emitting device 1 of this embodiment can reduce the number of voids contained in the bonding layer 40 when melting the glass frit and forming the bonding layer 40 by providing a groove 28 approximately in the center of the width direction of the bonding layer 40. This suppresses the phenomenon in which multiple voids contained in the bonding layer 40 connect in the width direction of the first bonding layer 26, causing leakage in the hermetic sealing of the first bonding layer 26. Furthermore, it suppresses the phenomenon in which the bonding strength of the first bonding layer 26 and the second bonding layer 27 is reduced due to voids. Thus, both hermetic sealing and bonding strength can be achieved.

[0039] To explain in more detail, generally, when a bonding layer 40 is formed by a paste in which glass frit and binder are dispersed in a solvent, gases such as CO2 contained in the paste remain even after the glass frit is heated and melted, then cooled and solidified to form the bonding layer 40, and become voids contained in the bonding layer 40.

[0040] In contrast, in the structure of the light-emitting device 1 of this embodiment, a groove 28 is provided at a position in contact with the unsolidified bonding layer 40. Therefore, when melting the glass frit, pressing the light-transmitting member 30 toward the package substrate 20 causes the gas present between the glass frit particles to move into the space within the groove 28 or to the non-bonded portion 29 located on the lower surface of the light-transmitting member 30 above the groove 28. This reduces the voids contained in the first bonding layer 26 and the second bonding layer 27.

[0041] Furthermore, it is desirable that the end portion 28a of the groove 28 extends across the second bonding layer 27, reaches the end face of the package substrate 20, and opens to the end face, as shown in Figure 1(c). Because the end portion 28a of the groove 28 opens to the end face of the package substrate 20, the space within the groove 28 is connected to the space surrounding the package substrate 20. Therefore, when the glass frit is heated to several hundred degrees Celsius during the formation of the bonding layer 40, a pressure difference is created between the pressure at the end portion 28a of the groove 28 and the pressure in the space within the groove 28 that is in contact with the heated bonding layer 40, due to the temperature difference with the surrounding space. This pressure difference promotes the movement of gas present between the particles of the glass frit into the space within the groove 28 or to the non-bonded portion 29 above the groove 28.

[0042] Furthermore, by providing the groove 28, when the glass frit is melted and the bonding layer 40 is formed, the molten glass can accumulate at the top of the groove 28 as shown in Figure 1(b). This prevents the molten glass from overflowing onto the mounting area 21 or the periphery of the package substrate 20, thus preventing malfunctions in the light-emitting device 1.

[0043] Furthermore, as shown in Figure 1(b), the glass accumulated in the groove 28, after cooling and solidifying, protrudes into the groove 28, forming a non-joint portion 29 that is in contact with the side surface of the groove 28. Because the non-joint portion 29 protruding into the groove 28 has a shape that interlocks with the groove 28, it generates an anchoring effect, which strengthens the bond between the light-transmitting member 30 and the package substrate 20.

[0044] <Manufacturing method> The manufacturing method of the light-emitting device of this embodiment will be described below with reference to Figures 2 to 4. Figures 2(a) to 2(e) are explanatory diagrams showing the manufacturing process. Figures 3(a) and 3(b) are diagrams illustrating the movement of voids, and Figures 4(a) and 4(b) are cross-sectional photographs of the bonding layer 40 manufactured in this embodiment and in comparative examples.

[0045] (Process for forming the frit glass paste layer 41) As shown in Figure 2(a), first, a frit glass paste in which glass frit and binder are dispersed in a solvent is screen printed onto the lower surface of the light-transmitting member 30 to form a frit glass paste layer 41 in the shape of a predetermined width frame. In this step, the light-transmitting member 30 is in the form of a substrate with multiple units connected together.

[0046] The thickness of the frit glass paste layer 41 is printed to be thinner than the depth of the groove 28, for example, 2 μm, if the groove depth is 10 μm. The thickness of the frit glass paste layer 41 needs to be smaller than the depth of the groove 28 because it is desirable to prevent contact between the groove 28 and the bonding layer 40.

[0047] The particle size of the frit glass contained in the frit glass paste is smaller than the film thickness of the frit glass paste layer 41 to be formed. For example, an average particle size of 0.1 to 10 μm or a particle size distribution D50 of approximately 0.1 to 10 μm is used.

[0048] For the frit glass paste, an organic solvent can be used as the solvent. A resin (e.g., ethylcellulose) can be used as the binder.

[0049] (Calibration process) As shown in Figure 2(b), the frit glass paste layer 41 printed on the translucent member is calcined to remove the solvent contained in the frit glass paste and to remove the binder by calcination. This forms an unmelted glass frit layer.

[0050] The calcination temperature is set to a temperature that evaporates the solvent and calcines the binder, but does not melt the glass frit. For example, as shown in Figure 2(b), heating is performed sequentially at 180°C for 40 minutes, 350°C for 60 minutes, and 400°C for 10 minutes.

[0051] During the debinding (solvent removal) process in calcination, most of the CO2 generated is released to the outside of the frit glass paste layer 41, but some remains.

[0052] (Process for separating the light-transmitting member 30 into individual pieces) As shown in Figure 2(c), the light-transmitting member 30 is divided into individual pieces, for example, 2.55 mm squares, by dicing.

[0053] (Process for separating the package substrate 20 into individual pieces) On the other hand, as shown in Figure 2(d), a package substrate 20 in which a recess 25 and electrodes 22 and 23 are formed is prepared by connecting multiple such substrates, and after forming grooves 28 on the terraces 22a around the recess 25, the substrate is divided into individual pieces by dicing.

[0054] The light-emitting element 10 is bonded to the mounting area 21 at the bottom of the recess 25 of the individualized package substrate 20.

[0055] (Joining layer formation process) A light-transmitting member 30 is mounted on the groove 28 on the upper surface of the individualized package substrate 20 so that the center of the glass frit layer in the width direction aligns with it.

[0056] The main firing process is performed by irradiating the translucent member 30 with a laser from above toward the glass frit layer to heat it, or by heating and melting the glass frit layer by hot pressing, while simultaneously pressing the translucent member 30 toward the package substrate 20.

[0057] During the final firing, the frit glass particles melt. The gas remaining between the frit glass particles becomes voids contained in the molten glass. However, the molten glass that forms the first bonding layer 26 and the second bonding layer 27 of the bonding layer 40 is sandwiched between the light-transmitting member 30 and the package substrate 20 and subjected to pressing force, whereas the lower part of the non-bonded portion 29 is a groove 28, and therefore no pressing force is applied to the molten glass there. Consequently, the voids in the regions of the first bonding layer 26 and the second bonding layer 27, where pressing force is applied, move to the region of the non-bonded portion 29 as shown in Figure 3(a). Furthermore, the air in the groove 28 expands when the frit glass layer is heated and is pushed out into the atmosphere from the end 28a, creating negative pressure inside the groove 28. This creates a pressure difference between the space inside the groove 28 and the pressure at the end 28a, and the voids in the non-bonded portion 29 are released into the space of the groove 28. Therefore, as shown in Figure 3(b), the number of voids in the first bonding layer 26 and the second bonding layer 27 can be reduced.

[0058] Furthermore, although pressing force is applied to the molten glass in the areas that will become the first bonding layer 26 and the second bonding layer 27 as described above, the molten glass accumulates at the top of the groove 28 and does not overflow onto the mounting area 21 side and peripheral side of the package substrate 20. Therefore, the number of defective products due to overflow of molten glass can be reduced, and the glass accumulated at the top of the groove 28 does not overflow onto the upper side of the groove 28. By making contact, it acts as a wedge, firmly bonding the light-transmitting member 30 to the package substrate 20.

[0059] <Results of room temperature storage test> After leaving the light-emitting device 1 manufactured using the above manufacturing method at room temperature for three months, the peeling of the bonding layer 40 was visually inspected. It was confirmed that no peeling of the bonding layer 4 had occurred.

[0060] <Industrial applicability> The light-emitting device 1 of this embodiment can be used in devices that require ultraviolet light, such as germicidal light sources (for sterilizing slippers in medical facilities, etc.), air purifiers, water purifiers, and the like.

[0061] Furthermore, the structure of the light-emitting device 1 of the present invention is not limited to a light-emitting device 1 that emits ultraviolet light; any light-emitting device 1 that hermetically seals the light-emitting element 10 can be used for any wavelength of light-emitting device 1. [Explanation of Symbols]

[0062] 1. Light-emitting device 2 Package substrates 3 Light-transmitting member 4 Bonding layer 5 recesses 10 light-emitting elements 20 Package substrates 21 Loading area 22 electrodes 23 electrodes 22a Terrace 24 Thermal Oxide Film 25 recesses 26 1st bonding layer 27 Second bonding layer 28 Groove 28a end 29 Non-joint part 30 Light-transmitting member 40 Bonding layer 41. Frit glass paste layer

Claims

1. The package comprises a package substrate, a light-emitting element mounted in a predetermined mounting area on the upper surface of the package substrate, a light-transmitting member covering the area on the package substrate where the light-emitting element is mounted and transmitting light emitted by the light-emitting element, and a bonding layer joining the upper surface of the package substrate and the lower surface of the light-transmitting member around the mounting area of ​​the package substrate, and hermetically sealing the space around the light-emitting element. The bonding layer is made of glass, The bonding layer is arranged to surround the mounting area with a predetermined width. In the portion of the upper surface of the package substrate where the bonding layer is arranged, a groove narrower than the bonding layer is provided so as to surround the mounting area. The bonding layer includes a first bonding layer that surrounds the mounting area on the side closer to the mounting area than the groove, and a second bonding layer that surrounds the mounting area on the side further from the mounting area than the groove. A light-emitting device characterized in that there is a space at the bottom surface of the groove that is not in contact with the bonding layer.

2. A light-emitting device according to claim 1, characterized in that the bonding layer is not in contact with the bottom surface of the groove.

3. A light-emitting device according to claim 1, characterized in that a space is formed in which the bonding layer is not filled in at least the portion of the groove that is in contact with the bottom surface.

4. A light-emitting device according to claim 1, characterized in that a portion of the groove crosses the second bonding layer and reaches the end face of the package substrate.

5. A light-emitting device according to claim 1, characterized in that the glass constituting the bonding layer is formed by welding a plurality of glass particles to each other.

6. A light-emitting device according to claim 1, characterized in that the width of the first bonding layer is the same as the width of the second bonding layer.

7. A light-emitting device according to claim 1, characterized in that the depth of the groove is greater than or equal to the thickness of the bonding layer.

8. A light-emitting device according to claim 1, characterized in that the width of the first bonding layer is greater than or equal to the width of the groove.

9. A light-emitting device according to claim 8, characterized in that the width of the groove is 10 μm or more and 100 μm or less.

10. A light-emitting device according to claim 1, wherein the light-emitting element emits deep ultraviolet light.

11. A glass paste layer formation step involves forming a frame-shaped glass paste layer of a predetermined width on the lower surface of a light-transmitting member that transmits light of a predetermined wavelength, using a glass paste containing glass frit and a solvent. A calcination step involves calcining the glass paste layer printed on the light-transmitting member to remove the solvent and create an unmelted glass frit layer. A package substrate preparation step of preparing a package substrate having a light-emitting element mounted on a mounting area on its upper surface, wherein a groove is formed around the mounting area that has a frame shape corresponding to the frame shape of the glass frit layer and is narrower than the glass frit layer, and is positioned at a location corresponding to the center in the width direction of the glass frit layer, A mounting step in which the light-transmitting member is mounted such that the glass frit layer overlaps with the groove on the upper surface of the package substrate, A method for manufacturing a light-emitting device, comprising a bonding layer formation step, in which the glass frit layer is heated and melted to form a first bonding layer surrounding the mounting area on the side closer to the mounting area than the groove, and a second bonding layer surrounding the mounting area on the side further from the mounting area than the groove, the first bonding layer and the second bonding layer bonding the upper surface of the package substrate and the lower surface of the light-transmitting member, and the molten glass frit layer is not brought into contact with the bottom surface of the groove, thereby forming a space within the groove.

12. A method for manufacturing a light-emitting device according to claim 11, characterized in that, in the bonding layer formation step, the thickness of the glass paste layer to be formed is made thinner than the depth of the groove, so as to prevent the molten glass frit layer from coming into contact with the bottom surface of the groove.

Images