Semiconductor light emitting device and water sterilization device

Abstract

A semiconductor light-emitting device is provided that improves the bonding reliability of the substrate and the cover, and has high hermetic reliability. A first bonding pattern (6) made of metal is formed on the substrate (1) in a manner surrounding the semiconductor light-emitting element, and a second bonding pattern (5) with a shape corresponding to the first bonding pattern (6) is provided on the base (4c) and flange (4b) of the dome-shaped transparent body. The first and second bonding patterns (5, 6) are bonded together by solder to seal the space inside the convex cover (4a). When viewed from the top surface, the first and second bonding patterns (5, 6) are rectangular rings surrounding the semiconductor light-emitting element. The edges of the corners (51, 61) of the first and second bonding patterns (5, 6) are located on the outer side of the annular base (4c) of the convex cover (4a). The edges of the straight sections (52, 62) sandwiched by the corners (51, 61) of the first and second bonding patterns (5, 6) are located on the semiconductor light-emitting element side of the annular base (4c) of the convex cover (4a).

Description

Technical Field

[0001] The present invention relates to a semiconductor light-emitting device in which the space surrounding the semiconductor light-emitting element is hermetically sealed. Background Technology

[0002] Conventionally, in semiconductor light-emitting devices requiring airtightness, the airtight sealing is achieved, for example, by using a structure where a light-transmitting optical element is bonded to a cavity-shaped substrate as disclosed in Patent Document 1, or by using a structure where a light-transmitting cavity-shaped optical element is bonded to a flat substrate as disclosed in Patent Document 2. For example, solder such as AuSn is used to bond and seal optical elements such as glass and heat-dissipating substrates such as ceramic substrates.

[0003] Furthermore, in the aforementioned hermetically sealed packaging, a problem arises where solder overflows beyond the bonding pattern when bonding transparent optical elements to the substrate using solder. Therefore, Patent Document 3 proposes a structure that suppresses solder overflow from the bonding pattern by forming films such as oxide films that reduce solder wettability at the inner and outer peripheries of the bonding area. Furthermore, Patent Document 4 proposes a structure that forms a recessed structure on the substrate to collect overflowing solder within the recess, suppressing its wetting and expansion beyond the recess.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2015-18873

[0007] Patent Document 2: Japanese Patent No. 5838357

[0008] Patent Document 3: Japanese Patent Application Publication No. 2015-073027

[0009] Patent Document 4: Japanese Patent Application Publication No. 2007-103909 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] In hermetic packaging, structures such as those in Patent Documents 3 and 4, which pre-form an oxide film or groove on the substrate to suppress the overflow of molten solder from the bonding pattern during the bonding of the optical element and the heat-generating substrate, lead to increased costs.

[0012] Therefore, the object of the present invention is to provide a new semiconductor light-emitting device that improves the bonding reliability of the substrate and the cover and has high hermetic reliability.

[0013] Methods for solving problems

[0014] To achieve the above objectives, the semiconductor light-emitting device of the present invention includes a substrate, a semiconductor light-emitting element mounted on the substrate, and a dome-shaped transparent body mounted on the substrate. The dome-shaped transparent body is configured with a convex cover portion having an annular base portion covering the space surrounding the semiconductor light-emitting element, and a flange portion extending outward from the outer periphery of the annular base portion. A first bonding pattern made of metal is formed on the substrate to surround the semiconductor light-emitting element. A second bonding pattern with a shape corresponding to the first bonding pattern is provided on the base portion and the flange portion of the dome-shaped transparent body. The first bonding pattern and the second bonding pattern are bonded together by solder to seal the space within the convex cover portion. When viewed from the top surface, the first bonding pattern and the second bonding pattern are rectangular rings surrounding the semiconductor light-emitting element. The edges of at least the inner periphery of the corners of the first bonding pattern and the second bonding pattern are located outside the outer periphery of the annular base of the convex cover. The edges of at least the inner periphery of the straight sections of the first bonding pattern and the second bonding pattern that are sandwiched by the corners are located closer to the semiconductor light-emitting element than the outer periphery of the annular base of the convex cover.

[0015] Invention Effects

[0016] According to the present invention, when viewed from the top surface, the bonding pattern of the substrate and the dome-shaped transparent body is a rectangular ring, with its corners located outside the annular base of the convex cover portion that bears the load when the dome-shaped transparent body is pressed during bonding. Therefore, the generation of pores in the bonding portion is suppressed, and a semiconductor light-emitting device with high bonding reliability and high hermetic reliability can be provided. Attached Figure Description

[0017] Figure 1 (a) is a top view of the semiconductor light-emitting device of Embodiment 1, and (b) is a cross-sectional view along line A-A'.

[0018] Figure 2 (a) is a top view of the dome-shaped transparent body 4 of the semiconductor light-emitting device of Embodiment 1, and (b) is a cross-sectional view.

[0019] Figure 3 This is a B-B' cross-sectional view of the semiconductor light-emitting device of Embodiment 1.

[0020] Figure 4 (a) is a top view of the substrate 1 of the semiconductor light-emitting device according to Embodiment 1, and (b) is a cross-sectional view.

[0021] Figure 5 (a) is a top view of the dome-shaped transparent body 4 of the semiconductor light-emitting device of Embodiment 1, in which the bonding pattern 5 is provided, and (b) is a cross-sectional view.

[0022] Figure 6(a) is an explanatory diagram showing the flow of molten solder 7 in the bonding process during the manufacturing of the semiconductor light-emitting device of Embodiment 1, and (b) is an explanatory diagram showing the flow of molten solder 7 in the bonding process during the manufacturing of the semiconductor light-emitting device of the comparative example.

[0023] Figure 7 (a) is a C-C' cross-sectional view of the solder 7 during the bonding process of the semiconductor light-emitting device in Embodiment 1, showing the state of the bonding pattern being spread by the solder 7. (b) is a D-D' cross-sectional view.

[0024] Figure 8 This is a cross-sectional view showing an example of the layer structure of the bonding patterns 5 and 6 of the semiconductor light-emitting device according to Embodiment 1.

[0025] Figure 9 (a) and (b) are bottom views showing the state in which the bonding pattern 5 on the side of the dome-shaped transparent body 4 is equipped with solder 7 (before melting) during the manufacturing process of the semiconductor light-emitting device in Embodiment 1.

[0026] Figure 10 (a) is a top view of the semiconductor light-emitting device of Embodiment 2, and (b) is a cross-sectional view along E-E'.

[0027] Figure 11 (a) is a top view of the substrate 1 of the semiconductor light-emitting device according to Embodiment 2, and (b) is a cross-sectional view.

[0028] Figure 12 (a) is a top view of the semiconductor light-emitting device of Embodiment 2, and (b) is a cross-sectional view along F-F'.

[0029] Figure 13 This is an explanatory diagram showing the flow of molten solder 7 during the bonding process in the manufacturing of the semiconductor light-emitting device of Embodiment 2.

[0030] Figure 14 This is a cross-sectional view of the semiconductor light-emitting device of Embodiment 2, showing the state in which the solder 7 wets and expands the bonding pattern.

[0031] Figure 15 (a) is a top view of the semiconductor light-emitting device of Modification 1 of Embodiment 2, and (b) is a cross-sectional view.

[0032] Figure 16 (a) is a top view of the semiconductor light-emitting device of Modification 2 of Embodiment 2, and (b) is a cross-sectional view. Detailed Implementation

[0033] The following describes a semiconductor light-emitting device according to one embodiment of the present invention.

[0034] <<Implementation Method 1>>

[0035] use Figures 1 to 7 The structure of the semiconductor light-emitting device of Embodiment 1 will be described.

[0036] Figure 1 (a) and (b) show a top view and a cross-sectional view of the semiconductor light-emitting device of Embodiment 1.

[0037] The semiconductor light-emitting device of Embodiment 1 is configured to have a substrate 1, a semiconductor light-emitting element 3 having an electrode 2 mounted on the substrate 1, and a dome-shaped transparent body 4 mounted on the substrate 1.

[0038] like Figure 2 As shown in (a) and (b) are its top and cross-sectional views, the dome-shaped transparent body 4 has a convex cover portion 4a covering the space surrounding the semiconductor light-emitting element 3 and having an annular base 4c, and a flange portion 4b extending outward from the outer periphery of the annular base 4c. In this embodiment, the base 4c is an annular shape of a predetermined width. Furthermore, as... Figure 2 As shown in (a) and (b), the base 4c represents the root portion of the convex cover 4a, which forms the bottom surface of the dome-shaped transparent body 4 with the thickness of the convex cover 4a.

[0039] In this embodiment, both the substrate 1 and the flange 4b ​​are rectangular when viewed from the top surface, and a dome-shaped transparent body 4 is mounted on the substrate 1 with the corners facing the same direction. In this embodiment, the flange 4b ​​is slightly smaller than the substrate 1.

[0040] like Figure 3 As shown in the enlarged cross-sectional view, corresponding bonding patterns 5 and 6 are provided on the annular base 4c and flange 4b ​​of the dome-shaped transparent body 4 and on the substrate 1 that is in contact with them. The bonding patterns 5 and 6 are provided along the rectangular outline of the flange 4b ​​and the substrate 1.

[0041] Figure 4 (a) and (b) show a top view and a cross-sectional view of the substrate 1 with the bonding pattern 6. Furthermore, Figure 5 (a) and (b) show a top view and a cross-sectional view of a dome-shaped transparent body 4 with a joining pattern 5. According to Figure 4 (a) and Figure 5 (a) and Figure 1 As can be seen from (a) and (b), when viewed from the top surface, the shapes of the bonding patterns 5 and 6 are rectangular rings of a specified width formed in a manner that surrounds the semiconductor light-emitting element 3.

[0042] The joining pattern 5 provided on the dome-shaped transparent body 4 is composed of four straight sections 52 formed along each side of the shape constituting the dome-shaped transparent body 4 and corner sections 51 connecting adjacent straight sections 52.

[0043] The bonding pattern 6 provided on the substrate 1 is composed of four straight sections 62 formed along each side of the shape constituting the substrate 1 and corner sections 61 connecting adjacent straight sections 62.

[0044] The bonding patterns 5 and 6 are joined by solder 7 to form a bonding layer 7a (see reference). Figure 3 This seals the space 8 within the convex cover 4. The bonding layer 7a is impregnated and extended along the bonding pattern, with the ends generally rounded. Additionally, the ends may sometimes be slightly raised due to surface tension. Furthermore, the solder 7 may also contact the sides of the bonding pattern 5.

[0045] Preferably, the width of the bonding pattern 5 on the transparent body 4 side is narrower than the width of the bonding pattern 6 on the substrate 1 side.

[0046] Here, the corners 51 and 61 of the rectangular annular joining patterns 5 and 6 are configured such that at least the outer peripheral edges 51a and 61a are located outside the outer peripheral edge 41 of the annular base 4c of the convex cover portion 4a (see reference). Figure 1 (a)). In addition, the inner periphery edges 51b and 61b of the corners 51 and 61 of the preferred joining patterns 5 and 6 are also located outside the outer periphery 41 of the annular base 4c of the convex cover 4a.

[0047] Therefore, the joining pattern 5 provided on the dome-shaped transparent body 4 is configured such that the straight portion 52 partially overlaps with the base 4c, and at least a portion of the corner portion 51 is located outside the base 4c. That is, a region that does not overlap with the base 4c is provided in the corner portion 51.

[0048] On the other hand, the straight portions 52 and 62 of the rectangular annular joining patterns 5 and 6 are configured such that at least the inner peripheral edges 52b and 62b are located closer to the semiconductor light-emitting element 3 than the outer peripheral edge 41 of the annular base 4c of the convex cover portion 4a (see reference). Figure 1 (a)). Furthermore, the outer periphery edges 52a and 62a of the straight portions 52 and 62 of the rectangular annular joining patterns 5 and 6 are preferably located on the outer side of the outer periphery edge 41 of the base bottom 4c.

[0049] Therefore, the bonding pattern 6 provided on the substrate 1 is configured such that the straight portion 62 partially overlaps with the base 4c, and at least a portion of the corner portion 61 is located outside the base 4c. That is, a region that does not overlap with the base 4c is provided at the corner portion 61.

[0050] Thus, the semiconductor light-emitting device of this embodiment is configured to use rectangular annular bonding patterns 5 and 6, with corners 51 and 61 located outside the outer periphery 41 of the annular base 4c, which bears the most load applied to the convex cover portion 4a during bonding of the dome-shaped transparent body 4. On the other hand, the straight portions 52 and 62 of the bonding patterns 5 and 6 are configured such that at least a portion is located below the base 4c, which bears the most load. Therefore, during the bonding process, the load applied to the corners 51 and 61 of the bonding patterns 5 and 6 is smaller than the load applied to the straight portions 52 and 62.

[0051] Therefore, during the manufacturing process, when the substrate 1 is heated while a load is applied in the direction that presses the dome-shaped transparent body 4 against the substrate 1, the solder 7 disposed between the bonding patterns 5 and 6 begins to melt from the area sandwiched by the straight portions 52 and 62 that bear the most load (more specifically, the area that overlaps with the base 4c in the thickness direction). At the moment when this melting begins, the solder 7 in the area sandwiched by the corner portions 51 and 61 (the area that does not overlap with the base 4c in the thickness direction) does not melt, but is melted later. Thus, as Figure 6 As shown in (a), the melting direction of the solder 7 can be oriented from the center of the straight sections 52 and 62 toward the corner sections 51 and 61. That is, the bonding direction can be oriented from the center of the straight sections 52 and 62 toward the corner sections 51 and 61.

[0052] In the semiconductor light-emitting device of this embodiment, the solder 7 is melted from the straight sections 52 and 62 of the connecting patterns 5 and 6 toward the corners 51 and 61 while being joined. Therefore, even if pores are generated during melting, since the joining is performed by extruding the pores toward the corners 51 and 61, it is not easy for the pores to be drawn in, and pores are not easy to remain after cooling.

[0053] Thus, in the apparatus of this embodiment, a stable bonding layer 7a can be formed by the solder 7, and the generation of pores connecting the interior space 8 and the exterior space of the dome-shaped transparent body 4 can be suppressed. As a result, a semiconductor light-emitting device with high hermeticity can be provided.

[0054] In addition, the bonding patterns 5 and 6 can be formed from any metal among Ni, Cr, Au, Cu, Pt, Ti, Pd and W, or from a laminate of two or more of the aforementioned metals.

[0055] Solder 7 can be, for example, AuSn solder. The solder supplied during the manufacturing process can be in sheet form or in dot form.

[0056] The semiconductor light-emitting element 3 can use a light-emitting diode (LED) or a laser light-emitting diode (including a surface-emitting laser). The semiconductor light-emitting element 3 can be selected to emit an appropriate emission wavelength corresponding to the application of the semiconductor light-emitting device, such as ultraviolet light, visible light, or infrared light. The dome-shaped transparent body 4 is made of a material that allows light emitted from the semiconductor light-emitting element 3 to pass through.

[0057] For example, as a semiconductor light-emitting element 3, it is possible to use an element that emits ultraviolet light in a wavelength range of 210 nm or more and 310 nm or less.

[0058] In this case, the dome-shaped transparent body 4 can be a transparent body with at least the convex cover 4a made of a material that allows deep ultraviolet light to pass through (e.g., quartz, borosilicate glass, sapphire glass).

[0059] The semiconductor light-emitting element 3 is composed of a compound semiconductor and has at least a p-type semiconductor layer, a light-emitting layer, and an n-type semiconductor layer. Furthermore, as a light-emitting diode emitting ultraviolet light with a wavelength of 200 nm to 405 nm, aluminum nitride-based, gallium nitride-based, and aluminum gallium nitride-based semiconductor light-emitting elements can be used.

[0060] The semiconductor light-emitting element 3 is mounted on the electrode 2 formed on the substrate 1 using a suitable bonding material. In this embodiment, AuSn bonding material is used for mounting.

[0061] The semiconductor light-emitting element 3 can also be mounted on the electrode 2 via a sub-mounting substrate (not shown). Furthermore, the number of elements mounted on a substrate may not be one. The substrate 1 is not limited to a flat plate shape as in this embodiment; it may also be shaped to have a recess at the mounting position of the semiconductor light-emitting element 3.

[0062] The substrate 1 can be aluminum nitride (AlN) as a substrate that can maintain hermeticity. Regarding the substrate, in addition to aluminum nitride (AlN), ceramics composed of nitrides, carbides, or oxides, such as silicon nitride (Si3N4), silicon carbide (SiC), and alumina (Al2O3), can also be used. It can be a high-temperature fired ceramic substrate or a low-temperature fired ceramic substrate. By using the ceramic substrate 1, heat generated by the semiconductor light-emitting element 3 can be dissipated efficiently, and due to its UV resistance, light output can be maintained for a long time even when the semiconductor light-emitting element 3 emits ultraviolet light.

[0063] A semiconductor light-emitting element 3 is mounted on an electrode 2 formed on a substrate 1. The electrode 2 is electrically connected to the semiconductor light-emitting element and is continuously formed with a back electrode (not shown) formed on the back side of the substrate 1 and a through electrode formed through the substrate 1, thereby supplying power to the semiconductor light-emitting element 3 from the outside. In addition to the semiconductor light-emitting element 3, other electronic components such as Zener diodes and photodiodes can also be mounted on the electrode 2, depending on the application.

[0064] Alternatively, a material can be placed in the hollow section 8 to reduce the refractive index difference between the semiconductor light-emitting element 3 and the dome-shaped transparent body 4.

[0065] Fine irregularities can be formed on the bottom surface of the dome-shaped transparent body 4 (the surfaces of the flange portion 4b and the base portion 4c on the side facing the substrate 1), thus roughening it. By roughening the bottom surface of the transparent body 4, it can be made into a shape where the outer side of the lens is slightly raised, allowing bonding to be performed from the inside to the outside during assembly, providing a semiconductor light-emitting device with higher bonding stability. Preferably, the roughness amount is set such that the raised amount (the difference in height between the inner and outer sides of the bottom surface of the dome-shaped transparent body 4) is smaller than the thickness of the bonding pattern 6 on the substrate side, so as to avoid bonding defects caused by excessive raised amount.

[0066] <Manufacturing Method>

[0067] An example of a method for manufacturing a semiconductor light-emitting device according to this embodiment will be described.

[0068] For example, an AlN substrate 1 is prepared, and the aforementioned rectangular annular bonding pattern 6 and electrode 2 are pre-formed. For example, Figure 8 As shown, the layer structure of the bonding pattern 6 is configured such that a NiCr layer, an Au layer, a Ni layer, and an Au layer are sequentially stacked from the substrate 1 side. Preferably, the uppermost layer of the bonding pattern 6 is a material that melts during bonding and mixes with molten solder 7 to change the composition of solder 7, thereby forming a eutectic bonding layer with a melting point higher than that of solder 7. For example, when using AuSn as solder 7, it is preferable to set the uppermost layer of the bonding pattern 6 as an Au layer.

[0069] On the other hand, a dome-shaped transparent body 4 made of quartz glass is prepared, and the aforementioned rectangular annular joining pattern 5 is pre-formed on the base 4c and the flange 4b. For example, Figure 8 As shown, the layer structure of the bonding pattern 5 is configured such that a Ti layer, a Pd layer, a Cu layer, a Ni layer, and an Au layer are sequentially stacked from the side of the dome-shaped transparent body 4. Preferably, the uppermost layer of the bonding pattern 5 is a material that melts during bonding and mixes with the molten solder 7 to change the composition of the solder 7, thereby forming a eutectic bonding layer with a melting point higher than that of the solder 7. For example, when using AuSn as the solder 7, it is preferable to set the uppermost layer of the bonding pattern 5 as an Au layer.

[0070] A solder 7 for bonding is fixed to the surface of the bonding pattern 5 of the dome-shaped transparent body 4. The bonding solder 7 is, for example, AuSn. Regarding its shape, it can be as follows... Figure 9 As shown in (a), a sheet with the same shape as the rectangular annular joining pattern 5 but narrower in width than the joining pattern 5 can also be used as shown in (a). Figure 9 (b) is a dotted solder.

[0071] The sheet-like solder 7 is temporarily fixed to the bonding pattern 5 locally by laser welding. Regarding the dot-shaped solder 7, the molten solder 7 is dispersed in dots and welded to the bonding pattern 5. The diameter of the dot-shaped solder 7 is smaller than the width of the bonding pattern 5. The number of dot-shaped solder 7 welded to the bonding pattern 5 is preferably 20 to 36, more preferably 28.

[0072] Regarding the Au and Sn composition ratio of AuSn solder 7, the preferred Au concentration for both flake and dot forms is 73wt% to 83wt%, and more preferably 78wt%.

[0073] Next, a semiconductor light-emitting element 3 made of AlGaN-based material that emits ultraviolet light with a wavelength of 210 nm or more and 310 nm or less is mounted on the electrode 2 of the substrate 1.

[0074] Next, the dome-shaped transparent body 4 is mounted on the substrate 1 in such a way as to cover the semiconductor light-emitting element 3 on the substrate 1, and the position is aligned by overlapping the bonding pattern 5 and the bonding pattern 6.

[0075] Next, a load is applied to the apex of the dome-shaped transparent body 4, and the solder 7 is heated and melted while being pressed against the substrate 1.

[0076] Specifically, firstly, a substrate 1, on which a semiconductor light-emitting element is mounted, and a dome-shaped transparent body 4 are placed inside a bonding apparatus capable of adjusting the sealing gas. The dome-shaped transparent body 4 is positioned with its opening facing upwards, and the substrate is positioned above the dome-shaped transparent body 4 with the side on which the semiconductor light-emitting element is mounted facing downwards. Next, the substrate 1 is heated to a temperature slightly lower than the melting temperature of the solder 7, creating a vacuum state and removing moisture. Then, while purging the bonding apparatus with nitrogen at atmospheric pressure, the top of the dome-shaped transparent body 4 is pushed upwards via a movable part of the bonding apparatus, pressing the dome-shaped transparent body 4 against the substrate 1 from below, thus sealing the space 8. Next, the substrate 1 is heated to the melting temperature of the solder 7, held for a predetermined time, and then cooled, thereby forming a bonding joint and sealing the space 8 airtightly.

[0077] Therefore, as Figure 6As shown in (a), the solder 7 of the straight sections 52 and 62 of the joining pattern 5 melts first and flows toward the corners 51 and 61, and then the solder 7 of the corners 51 and 61 melts. Then, by cooling, the joining patterns 5 and 6 can be joined together by the solder 7.

[0078] Solder 7 melts to form a bonding layer.

[0079] The above method enables the manufacture of semiconductor light-emitting devices that emit ultraviolet light.

[0080] In the manufactured semiconductor light-emitting device, the corner of the bonding pattern 5 is positioned on the outside of the load-bearing base 4c, thereby suppressing the overflow of solder 7 into the space 8. Furthermore, it prevents the formation of voids.

[0081] Furthermore, by covering the semiconductor light-emitting element 3 with a dome-shaped transparent body 4 (quartz glass) with a curved surface to form an airtight space, total internal reflection is not easily generated, and the light extraction efficiency is increased.

[0082] <Comparative Example 1>

[0083] exist Figure 6 In (b), as a comparative example 1, the melting of solder 7 is shown when the bonding patterns 5 and 6 are formed integrally on the base 4c and the flange 4b.

[0084] In the comparative example, the joining patterns 5 and 6 are rectangular rings, with the outer peripheral edges 51a and 61a being approximately rectangular and the inner peripheral edges 51b and 61b being circular. Similar to Embodiment 1, the joining patterns 5 and 6 in the comparative example are configured such that the outer peripheral edges 51a and 61a are located outside the outer peripheral edge 41 of the annular base 4c of the convex cover portion 4a. However, unlike Embodiment 1, in the joining patterns 5 and 6 of the comparative example, the inner peripheral edges 51b and 61b are located inside the outer peripheral edge 41 of the annular base 4c of the convex cover portion 4a throughout the entire circumference.

[0085] In the structure of Comparative Example 1, X-ray transmission observation revealed bubbles in the bonding layer 7a on the bonding patterns 5 and 6. The semiconductor light-emitting device of Comparative Example 1 produced more bubbles than the semiconductor light-emitting device of Embodiment 1. In X-ray transmission observation of a sample of the semiconductor light-emitting device of Embodiment 1, no obvious bubbles were observed forming the bonding layer 7a. This is believed to be because, in the semiconductor light-emitting device of Comparative Example 1, melting began from multiple locations on the load-bearing base 4c, resulting in contact between the bonding portions joined from multiple directions, causing pores to form at the contact points. Furthermore, the locations of these pores were random. Therefore, pores connecting the interior space 8 and the exterior space of the dome-shaped transparent body 4 may be formed.

[0086] <<Implementation Method 2>>

[0087] use Figures 10-14 The semiconductor light-emitting device of Embodiment 2 will be described. Figure 10 (a) and (b) are top and cross-sectional views of the semiconductor light-emitting device b according to Embodiment 2. Figure 11 (a) and (b) are top and cross-sectional views of the substrate 1 of the semiconductor light-emitting device according to Embodiment 2.

[0088] like Figure 10 , Figure 11 and Figure 12 Thus, the semiconductor light-emitting device of Embodiment 2 has the same structure as the device of Embodiment 1. However, the difference from Embodiment 1 is that a protrusion 63 extending toward the semiconductor light-emitting element 3 is provided on the inner periphery edge 62b of the straight portion 62 of the bonding pattern 6 on the substrate 1. In this embodiment, the edge of the protrusion 63 is approximately arc-shaped. The protrusion 63 is provided at the midpoint between the corners 61 and 61. There are four protrusions 63.

[0089] like Figure 10 (a), (b) Figure 12 In this way, the end of the protrusion 63 of the preferred joining pattern 6 extends toward the semiconductor light-emitting element 3 from the inner periphery 42 of the annular base 4c of the dome-shaped transparent body 4.

[0090] The shape of the joining pattern 5 of the dome-shaped transparent body 4 is the same as that in Embodiment 1 (see reference). Figure 5 That is, the bonding pattern 5 on the side of the dome-shaped transparent body 4 does not have a protrusion shape corresponding to the protrusion 63 of the bonding pattern 5 on the side of the substrate 1.

[0091] The metal bonding pattern 6 has a wider protrusion 63. Therefore, during the manufacturing process of bonding the dome-shaped transparent body 4, when the substrate 1 is heated, the temperature of the protrusion 63 is higher than that of the surrounding area. Furthermore, a portion of the bonding patterns 5 and 6 of the straight sections 62 adjacent to the protrusion 63 overlaps with the base 4c of the dome-shaped transparent body 4. Therefore, during bonding, the base 4c presses down, causing the solder 7 at the bonding patterns 5 and 6 of the straight sections 62 adjacent to the protrusion 63 to melt first. Thus, the melting start position is fixed at the bonding patterns 5 and 6 of the straight sections 62 adjacent to the protrusion 63, as shown below. Figure 13 As shown, compared to Embodiment 1, the flow of molten solder from the straight portion 62 toward the corner portion 61 can be generated more clearly, and a stable bonding layer can be formed. Furthermore, the flow of molten solder involves fewer contact points, thus suppressing the formation of porosity. Therefore, the formation of porosity connecting the interior space 8 of the dome-shaped transparent body 4 to the exterior space can be suppressed.

[0092] Furthermore, compared to the semiconductor light-emitting device of Embodiment 1, the semiconductor light-emitting device of Embodiment 2 can suppress the generation of solder balls.

[0093] Here, in the semiconductor light-emitting device of Embodiment 1, sufficient solder 7 needs to be supplied in order to form the bonding layer 7a. However, if the amount of solder 7 is excessive, such as... Figure 7 As shown, the remaining solder 7 overflows from the bonding patterns 5 and 6 and does not wet the surface of the substrate 1. Therefore, it may form solidified spherical solder balls 71. These solder balls 71 may protrude into the space 8 and become visually identifiable, thus becoming an appearance defect. They may also reach the electrodes 2 on the substrate 1, causing a decrease in reliability, such as the light-emitting element not lighting up. Specifically, in... Figure 7 In the CC′ section shown in (a), compared with the DD′ section, the solder ball 71 is more likely to protrude into the space 8.

[0094] In contrast, in the semiconductor light-emitting device of Embodiment 2, when the amount of solder 7 is large, such as Figure 14 As shown, the solder can be wetted and spread on the protrusion 63, and the solder can be held in place by surface tension. Therefore, it is possible to prevent the solder 7 from overflowing from the bonding pattern 6 and forming solder balls. That is, it is possible to increase the design freedom of the solder 7 and form a highly reliable bonding layer 7a.

[0095] Therefore, it is possible to suppress short circuits caused by contact between the solder ball and electrode 2, and to suppress defects.

[0096] The other structures, functions, and effects of the device in Embodiment 2 are the same as those in Embodiment 1, so the description is omitted.

[0097] <Modification 1 of Implementation Method 2>

[0098] Figure 15 Images (a) and (b) show a top view and a cross-sectional view of a semiconductor light-emitting device of Modification 1 of Embodiment 2. In Embodiment 2... Figure 10 In the structures shown in (a) and (b), the end of the protrusion 63 extends towards the semiconductor light-emitting element 3 from the inner edge 42 of the base 4c of the dome-shaped transparent body 4. However, as in Modified Example 1... Figure 15 As with devices (a) and (b), the end of the protrusion 63 can also be located on the outer side of the edge 42 inside the base 4c.

[0099] <Modification 2 of Implementation Method 2>

[0100] Figure 16 Images (a) and (b) show a top view and a cross-sectional view of a semiconductor light-emitting device of Embodiment 2, Modification 2. In Embodiment 2... Figure 10 In the structures shown in (a) and (b), the bonding pattern 6 on the substrate 1 side is provided with a protrusion 63, but the bonding pattern 5 of the dome-shaped transparent body 4 is not provided with a protrusion. (See Modified Example 2) Figure 16 As in (a) and (b), a protrusion 64 may also be provided on the joining pattern 5 of the dome-shaped transparent body 4. The protrusion 64 is provided at a position opposite to the protrusion 63.

[0101] Furthermore, in embodiments 1 and 2, as well as variations 1 and 2, the shape of the convex cover 4a of the dome-shaped transparent body 4 is simply that the internal space 8 is convex relative to the substrate 1. Thus, the space 8 of the convex cover 4a can be hemispherical or semi-elliptical.

[0102] Furthermore, the shape of the convex cover 4a is not limited to a hemispherical or semi-elliptical shape; it can be any shape. For example, the shape of the convex cover 4a can also be a cuboid.

[0103] Furthermore, the base 4c of the convex cover 4a is not limited to being circular, but can also be elliptical.

[0104] <Implementation Method 3>

[0105] As Embodiment 3, a water sterilization apparatus using the semiconductor light-emitting device of Embodiments 1, 2 and Modifications 1, 2 will be described.

[0106] In a water sterilization device, a semiconductor light-emitting device and its driving circuit are arranged in the water supply path. The semiconductor light-emitting device sterilizes the water flowing in the supply path by irradiating it with deep ultraviolet light.

[0107] Furthermore, the semiconductor light-emitting devices of Embodiments 1 and 2 and their variations 1 and 2 can be used as LED packages for sealing deep ultraviolet LEDs, which are semiconductor light-emitting elements 3. They can also be used as laser packages for sealing surface-emitting lasers, which are semiconductor light-emitting elements.

[0108] Label Explanation

[0109] 1: Substrate; 2: Electrode; 3: Semiconductor light-emitting element; 4: Dome-shaped transparent body; 4a: Convex cover; 4b: Flange; 4c: Base; 5, 6: Bonding pattern; 7: Solder; 8: Space; 41: Outer periphery of the base; 42: Inner periphery of the base; 51, 61: Corner of the bonding pattern; 52, 62: Straight part of the bonding pattern; 63, 64: Protrusion.

Claims

1. A semiconductor light-emitting device, characterized in that, The semiconductor light-emitting device has: substrate; A semiconductor light-emitting element, mounted on the substrate; and A dome-shaped transparent body is mounted on the substrate. The dome-shaped transparent body has a convex cover portion that covers the space surrounding the semiconductor light-emitting element and has an annular base portion, and a flange portion that extends outward from the outer periphery of the annular base portion. A first bonding pattern made of metal is formed on the substrate in such a way as to surround the semiconductor light-emitting element. A second joining pattern, corresponding in shape to the first joining pattern, is provided on the base and flange of the dome-shaped transparent body. The first joining pattern and the second joining pattern are joined by solder to seal the space inside the convex cover. When viewed from above, the first bonding pattern and the second bonding pattern are rectangular rings surrounding the semiconductor light-emitting element. At least the inner peripheral edges of the corners of the first bonding pattern and the second bonding pattern are located outside the outer peripheral edge of the annular base of the convex cover. At least the inner peripheral edges of the straight portions of the first bonding pattern and the second bonding pattern that are sandwiched by the corners are located closer to the semiconductor light-emitting element than the outer peripheral edge of the annular base of the convex cover.

2. The semiconductor light-emitting device according to claim 1, characterized in that, The base is circular.

3. The semiconductor light-emitting device according to claim 1 or 2, characterized in that, The width of the second joining pattern is narrower than the width of the first joining pattern.

4. The semiconductor light-emitting device according to claim 1 or 2, characterized in that, A protrusion extending toward the semiconductor light-emitting element is provided on the inner periphery of the straight portion of the first bonding pattern located at the middle part between the corners.

5. The semiconductor light-emitting device according to claim 4, characterized in that, The end of the protrusion of the first bonding pattern extends toward the semiconductor light-emitting element side compared to the inner periphery of the annular base of the convex cover.

6. The semiconductor light-emitting device according to claim 4, characterized in that, The second bonding pattern does not have a protrusion corresponding to the protrusion of the first bonding pattern.

7. The semiconductor light-emitting device according to claim 1 or 2, characterized in that, The flange of the dome-shaped transparent body is rectangular in shape, and the first joining pattern and the second joining pattern are arranged along the shape of the flange.

8. The semiconductor light-emitting device according to claim 1 or 2, characterized in that, The first bonding pattern is formed by any metal selected from Ni, Cr, Au, Cu, Pt, Ti, Pd and W, or by a stack of layers of two or more of the aforementioned metals.

9. The semiconductor light-emitting device according to claim 1, characterized in that, The solder is AuSn solder.

10. The semiconductor light-emitting device according to claim 1 or 2, characterized in that, The convex cover of the dome-shaped transparent body is made of a material that transmits deep ultraviolet light.

11. The semiconductor light-emitting device according to claim 1 or 2, characterized in that, The semiconductor light-emitting element emits ultraviolet light in the wavelength range of 210nm and above to 310nm.

12. The semiconductor light-emitting device according to claim 1 or 2, characterized in that, The semiconductor light-emitting element is a surface-emitting laser.

13. A water sterilization device comprising a light-emitting device and a driving circuit for the light-emitting device, wherein the light-emitting device is disposed in a water supply path and irradiates deep ultraviolet light onto the water flowing in the supply path, characterized in that, The light-emitting device is a semiconductor light-emitting device according to any one of claims 1 to 12.

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