Ultraviolet light emitting device and method of manufacturing the same

Abstract

Provided is an ultraviolet light emitting device that seals an ultraviolet light emitting element and achieves improved light extraction efficiency. The ultraviolet light emitting device (100) has a substrate (110), an ultraviolet light emitting element (120), and a fluororesin layer (140). The fluororesin layer (140) has an element covering portion (141) that covers a second surface (120b) of the ultraviolet light emitting element (120), and a substrate covering portion (142) that covers a mounting surface (110a) of the substrate (110). The substrate covering portion (142) has a flat portion (FS1) that has a flat surface (FS1a). A distance (H1) from a point (Q1) in the element covering portion (141) that is farthest from the second surface (120b) of the ultraviolet light emitting element (120) to the second surface (120b) of the ultraviolet light emitting element (120) is 1.3 times or more and 5 times or less of a distance (H2) from the flat surface (FS1a) of the flat portion (FS1) of the substrate covering portion (142) to the mounting surface (110a) of the substrate (110).

Description

TECHNICAL FIELD

[0001] The technical field of the present application relates to an ultraviolet light emitting device having an ultraviolet light emitting element and a manufacturing method thereof. BACKGROUND

[0002] In a light emitting device that emits visible light, a semiconductor light emitting element mounted on a substrate is sealed with a resin. The sealing resin is, for example, a silicone resin, an epoxy resin. The refractive index of these resins is larger than the refractive index of the atmosphere. Therefore, reflection at the interface of the semiconductor light emitting element and the sealing resin is suppressed. That is, the light extraction efficiency is high.

[0003] In recent years, a light emitting device using an ultraviolet light emitting element has been researched and developed. For example, in Patent Literature 1, a light emitting device in which a coating film 5 of glass or the like is provided on an ultraviolet light emitting element 2, and a sealing resin 4 of silicone or the like is provided on the coating film 5 is disclosed (paragraphs

[0020] -

[0029] of Patent Literature 1).

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2019-114741

[0005] However, ultraviolet light denatures silicone resins and epoxy resins. The resin that is cured or deteriorated due to ultraviolet light becomes a cause of cracking. Therefore, a light emitting device that does not use a silicone resin or an epoxy resin has been developed.

[0006] However, it is not necessarily easy to seal an ultraviolet light emitting element without using a resin suitable for sealing such as a silicone resin or an epoxy resin. In addition, in the case where a silicone resin or the like is not used, there is a tendency that the surface of the sealing member becomes flat and the light extraction efficiency decreases. SUMMARY

[0007] The technology of the present specification aims to provide an ultraviolet light emitting device that seals an ultraviolet light emitting element and achieves an increase in light extraction efficiency.

[0008] The ultraviolet light emitting device in the first aspect has a substrate, an ultraviolet light emitting element, and a fluororesin layer. The substrate has a mounting surface. The ultraviolet light emitting element includes a first surface having an electrode, a second surface on the opposite side of the first surface, and a side surface. The electrode of the first surface of the ultraviolet light emitting element is joined to the mounting surface of the substrate. The fluororesin layer has an element covering portion that covers the second surface of the ultraviolet light emitting element, and a substrate covering portion that covers the mounting surface of the substrate. The substrate covering portion has a flat portion having a flat surface on the opposite side of the mounting surface. The distance from the point in the element covering portion that is farthest from the second surface of the ultraviolet light emitting element to the second surface of the ultraviolet light emitting element is 1.3 times or more and 5 times or less of the distance from the flat surface of the flat portion of the substrate covering portion to the mounting surface of the substrate.

[0009] In the ultraviolet light emitting device, the fluororesin layer has an element covering portion and a substrate covering portion. The element covering portion is sufficiently raised compared with the film thickness of the substrate covering portion. Therefore, light emitted from the second surface of the ultraviolet light emitting element is less likely to be reflected when emitted to the outside of the ultraviolet light emitting device. The ultraviolet light emitting device has a high light extraction efficiency.

[0010] In the present specification, an ultraviolet light emitting device that seals an ultraviolet light emitting element and achieves an improvement in light extraction efficiency can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a schematic configuration view of an ultraviolet light emitting device 100 of the first embodiment.

[0012] Figure 2 is a view showing the shape of the ultraviolet light emitting device 100 of the first embodiment.

[0013] Figure 3 is a view for explaining a manufacturing method of the ultraviolet light emitting device 100 of the first embodiment (one of).

[0014] Figure 4 is a view for explaining a manufacturing method of the ultraviolet light emitting device 100 of the first embodiment (two of).

[0015] Figure 5 is a view for explaining a manufacturing method of the ultraviolet light emitting device 100 of the first embodiment (three of).

[0016] Figure 6 is a view for explaining a manufacturing method of the ultraviolet light emitting device 100 of the first embodiment (four of).

[0017] Figure 7 is a schematic configuration view of an ultraviolet light emitting device 200 in a modification example of the first embodiment.

[0018] Figure 8 is a schematic configuration view of an ultraviolet light emitting device 300 in a modification example of the first embodiment.

[0019] Figure 9 is a schematic configuration view of an ultraviolet light emitting device 400 in a modification example of the first embodiment.

[0020] EXPLANATION OF REFERENCE NUMERALS

[0021] 100... ultraviolet light emitting device; 110... substrate; 120... ultraviolet light emitting element; 130... bonding layer; 140... fluororesin layer; 150... air layer DETAILED DESCRIPTION

[0022] The following describes specific embodiments with reference to the drawings, taking an ultraviolet light emitting device and a manufacturing method thereof as an example. However, the technology of the present specification is not limited to these embodiments. An embodiment different from the embodiments can also be possible. Furthermore, the ratio of the thickness of each layer in each drawing is schematically shown and does not necessarily represent the actual ratio of the thickness.

[0023] (First Embodiment) 1. Ultraviolet light emitting device

[0024] Figure 1 is a schematic configuration diagram of an ultraviolet light emitting device 100 of the first embodiment. As shown in Figure 1 , the ultraviolet light emitting device 100 has a substrate 110, an ultraviolet light emitting element 120, a bonding layer 130, a fluororesin layer 140, and an air layer 150. The ultraviolet light emitting device 100 emits ultraviolet light.

[0025] The substrate 110 is a substrate for mounting the ultraviolet light emitting element 120. The substrate 110 has a mounting surface 110a. The mounting surface 110a is a surface for mounting the ultraviolet light emitting element 120. The substrate 110 has a base material 111, circuit patterns 112, 113, and a through-hole 114. The circuit pattern 112 is a pattern on the mounting surface 110a side of the substrate 110. The circuit pattern 113 is a pattern on the opposite side of the mounting surface 110a of the substrate 110. The through-hole 114 electrically connects the circuit pattern 112 and the circuit pattern 113. The through-hole 114 is filled with metal. The mounting surface 110a is the surface of the circuit pattern 112.

[0026] The ultraviolet light emitting element 120 is a semiconductor light emitting element that emits ultraviolet light. The light emitting wavelength of the ultraviolet light emitting element 120 is, for example, 200 nm or more and 320 nm or less. The ultraviolet light emitting element 120 has a first surface 120a, a second surface 120b, and a side surface 120c. The first surface 120a has an electrode. The first surface 120a opposes the mounting surface 110a of the substrate 110. The electrode of the first surface 120a of the ultraviolet light emitting element 120 is bonded to the mounting surface 110a of the substrate 110 via the bonding layer 130. The second surface 120b is a surface on the opposite side of the first surface 120a. The second surface 120b is a light extraction surface that extracts light to the outside of the ultraviolet light emitting element 120. The second surface 120b opposes the fluororesin layer 140. The side surface 120c is a surface other than the first surface 120a and the second surface 120b.

[0027] The bonding layer 130 is a layer for mounting the ultraviolet light emitting element 120 to the substrate 110. The bonding layer 130 bonds the electrode of the first surface 120a of the ultraviolet light emitting element 120 and the circuit pattern 112 of the mounting surface 110a of the substrate 110. The material of the bonding layer 130 is, for example, Au-Sn solder.

[0028] The fluororesin layer 140 is a light-transmissive fluororesin for appropriately extracting ultraviolet light emitted from the ultraviolet light emitting element 120 to the outside. The fluororesin layer 140 of course transmits ultraviolet light. The fluororesin layer 140 is fixed to the ultraviolet light emitting element 120 and the substrate 110.

[0029] The air layer 150 is a sealed space between the substrate 110 and the ultraviolet light emitting element 120. In the air layer 150, a gas is filled. The gas is, for example, the atmosphere. The air layer 150 is between the mounting surface 110a of the substrate 110 and the first surface 120a of the ultraviolet light emitting element 120. In addition, there is almost no air layer between the second surface 120b and the side surface 120c of the ultraviolet light emitting element 120 and the fluororesin layer 140.

[0030] 2. Material of fluororesin layer

[0031] The material of the fluororesin layer 140 is a fluororesin. The fluororesin is a polymer having a CF bond. The fluororesin is, for example, FEP. The refractive index of the fluororesin layer 140 is larger than the refractive index of the atmosphere. The refractive index of the fluororesin layer 140 is, for example, 1.2 or more and 1.6 or less.

[0032] 2-2. Region of fluororesin layer

[0033] As shown in FIG. 1, the fluororesin layer 140 has an element covering portion 141 and a substrate covering portion 142. Figure 1

[0034] The element covering portion 141 is a region occupying the vicinity of the center of the ultraviolet light emitting device 100. The element covering portion 141 covers the second surface 120b of the ultraviolet light emitting element 120. The element covering portion 141 is in contact with the second surface 120b of the ultraviolet light emitting element 120. The element covering portion 141 occupies a region higher than the second surface 120b of the ultraviolet light emitting element 120. The second surface 120b of the ultraviolet light emitting element 120 is rectangular, so the shape of a projection region obtained by projecting the element covering portion 141 toward the substrate 110 is also rectangular.

[0035] The substrate covering portion 142 is a region occupying the vicinity of the outer edge of the ultraviolet light emitting device 100. The substrate covering portion 142 covers the mounting surface 110a of the substrate 110. The substrate covering portion 142 is in contact with the mounting surface 110a of the substrate 110. The substrate covering portion 142 occupies a region outside the side surface 120c of the ultraviolet light emitting element 120. The substrate covering portion 142 is a region other than the element covering portion 141. The substrate covering portion 142 surrounds the periphery of the element covering portion 141. The substrate covering portion 142 is a region close to a ring shape.

[0036] 2-3. Shape of fluororesin layer

[0037] Figure 2 ​is a view showing the shape of the ultraviolet light emitting device 100 of the first embodiment. As shown in Figure 2 The surface extending from the side surface 120c of the ultraviolet light emitting element 120 is the boundary surface of the element covering portion 141 and the substrate covering portion 142.

[0038] The element covering portion 141 has a convex shape portion PR1 from the side of the ultraviolet light emitting element 120. The convex shape portion PR1 is a dome shape.

[0039] The point Q1 is the point farthest from the second surface 120b of the ultraviolet light emitting element 120 in the element covering portion 141. The point Q2 is the point obtained by orthogonally projecting the point Q1 toward the second surface 120b of the ultraviolet light emitting element 120. The point Q2 is located near the center of the second surface 120b of the ultraviolet light emitting element 120. The distance H1 is the distance between the point Q1 and the point Q2. The distance H1 is the film thickness of the thickest portion in the element covering portion 141.

[0040] The substrate covering portion 142 has a flat portion FS1 and a connecting portion JC1. The flat portion FS1 has a flat surface FS1a and a flat surface FS1b. The flat surface FS1a is the surface opposite to the mounting surface 110a of the substrate 110. The flat surface FS1b is the surface in contact with the mounting surface 110a of the substrate 110. The distance H2 is the distance between the flat surface FS1a and the flat surface FS1b. The distance H2 is the film thickness of the flat portion FS1.

[0041] The distance H1 is, for example, 200 μm or more and 500 μm or less. The distance H2 is, for example, 100 μm or more and 200 μm or less. The width W1 of the ultraviolet light emitting element 120, that is, the length of one side of the second surface 120b of the ultraviolet light emitting element 120 is, for example, 0.5 mm or more and 2 mm or less. The height of the ultraviolet light emitting element 120 is, for example, 0.3 mm or more and 0.7 mm or less.

[0042] The distance H1 from the point farthest from the second surface 120b of the ultraviolet light emitting element 120 in the element covering portion 141 to the second surface 120b of the ultraviolet light emitting element 120 is 1.3 times or more and 5 times or less of the distance H2 from the flat surface FS1a of the flat portion FS1 of the substrate covering portion 142 to the mounting surface 110a of the substrate 110. That is, the distance H1 is 1.3 times or more and 5 times or less of the distance H2. It is preferable that it be 1.4 times or more and 4 times or less. It is more preferable that it be 1.5 times or more and 3 times or less.

[0043] The distance H1 is, for example, 0.15 times or more and 0.8 times or less of the width W1. It is preferable that it be 0.2 times or more and 0.7 times or less. It is more preferable that it be 0.2 times or more and 0.6 times or less.

[0044] The connection portion JC1 is a region surrounding the element covering portion 141. The thickness of the connection portion JC1 increases toward the element covering portion 141. Therefore, the thickness of the connection portion JC1 is thicker than that of the flat portion FS1.

[0045] The fluororesin layer 140 does not fill the gap between the mounting surface 110 a of the substrate 110 and the first surface 120 a of the ultraviolet light emitting element 120 . This unfilled gap serves as an air layer 150 .

[0046] 3. Refractive index

[0047] The refractive index of the ultraviolet light-emitting element 120 is approximately 1.7. The refractive index of the fluororesin layer 140 is approximately 1.2 to 1.6. The refractive index of the atmosphere is 1. The refractive index of the ultraviolet light-emitting element 120, the fluororesin layer 140, and the atmosphere are higher in that order. In this case, total internal reflection is less likely to occur at the boundary between the materials.

[0048] In the first embodiment, the second surface 120b and side surface 120c of the ultraviolet light-emitting element 120 do not contact the air layer 150. As described above, the refractive index of the ultraviolet light-emitting element 120 is sufficiently greater than that of the air layer 150. Since the second surface 120b and side surface 120c of the ultraviolet light-emitting element 120, which extract light to the outside, do not contact the air layer 150 with a lower refractive index, light from the ultraviolet light-emitting element 120 is easily emitted outside the element. Consequently, the ultraviolet light-emitting device 100 achieves high light extraction efficiency.

[0049] 4. Manufacturing Method 4-1. Component Mounting Process

[0050] like Figure 3 As shown, an ultraviolet light-emitting element 120 is mounted on the mounting surface 110a of the substrate 110. For example, Au-Sn solder is placed on the mounting surface 110a of the substrate 110. The ultraviolet light-emitting element 120 is placed on the Au-Sn solder so that the electrodes on the first surface 120a of the ultraviolet light-emitting element 120 are in contact with the Au-Sn solder. Furthermore, the ultraviolet light-emitting element 120 is mounted on the substrate 110, for example, by reflow. This bonds the first surface 120a of the ultraviolet light-emitting element 120 to the mounting surface 110a of the substrate 110.

[0051] 4-2. Fluororesin sheet placement step

[0052] like Figure 4As shown, a fluororesin sheet F1 is placed on the second surface 120b of the ultraviolet light-emitting element 120. The fluororesin sheet F1 is a fluororesin having a size approximately equal to that of the ultraviolet light-emitting device 100. The width of the fluororesin sheet F1 is approximately equal to the width W1 of the ultraviolet light-emitting element 120. The fluororesin sheet F1 is made of, for example, FEP. The fluororesin sheet F1 has a first surface F1a and a second surface F1b. The second surface F1b is the surface opposite the first surface F1a. The first surface F1a of the fluororesin sheet F1 is in contact with the second surface 120b of the ultraviolet light-emitting element 120. The number of fluororesin sheets F1 is the same as the number of ultraviolet light-emitting elements 120. In other words, a fluororesin sheet F1 is placed on each ultraviolet light-emitting element 120.

[0053] 4-3. Fluororesin film placement step

[0054] like Figure 5 As shown, a fluororesin film F2 is placed on a fluororesin sheet F1. The material of the fluororesin sheet F1 and the fluororesin film F2 are the same. The thickness of the fluororesin film F2 is thinner than that of the fluororesin sheet F1. The fluororesin film F2 has a first surface F2a and a second surface F2b. The second surface F2b is the surface opposite to the first surface F2a. The first surface F2a of the fluororesin film F2 is in contact with the second surface F1b of the fluororesin sheet F1. Nothing is placed on the second surface F2b of the fluororesin film F2.

[0055] 4-4. Decompression process

[0056] Next, we will Figure 5 The stacked structure is placed in a vacuum heating device. The vacuum heating device is decompressed. The internal pressure of the vacuum heating device is, for example, 1 Pa or more and 100 Pa or less.

[0057] 4-5. Decompression and heating process

[0058] Next, the laminate is heated under the reduced pressure. The heating temperature is, for example, 100°C to 500°C. The heating temperature can be adjusted according to the melting points of the fluororesin sheet F1 and the fluororesin film F2. As a result, the fluororesin sheet F1 and the fluororesin film F2 melt almost simultaneously (see Figure 6 Thus, when the fluororesin film F2 is melted, the fluororesin sheet F1 is melted, and the fluororesin sheet F1 and the fluororesin film F2 are fused together. The holding time is, for example, 1 minute to 10 minutes.

[0059] 4-6. Re-pressing process

[0060] like Figure 6As shown, an element covering portion 141 is formed on the second face 120b of the ultraviolet light emitting element 120, and a substrate covering portion 142 is formed on the mounting face 110a of the substrate 110. Thus, the inside of the vacuum heating device is returned to the atmospheric pressure while maintaining the heating temperature. From the reduced pressure heating process to the pressure restoration process, the fluororesin sheet F1 and the fluororesin film F2 are fixed to the ultraviolet light emitting element 120 and the substrate 110.

[0061] 4-7. Placement Process

[0062] The laminate is left in the inside of the vacuum heating device for a while. Thus, the inside of the vacuum heating device is lowered to the room temperature. Alternatively, the inside of the vacuum heating device can be cooled to the room temperature.

[0063] 4-8. Other Process

[0064] The substrate 110 is cut into individual ultraviolet light emitting devices 100. Alternatively, other processes can be performed.

[0065] 5. Effects of the First Embodiment

[0066] The fluororesin layer 140 of the ultraviolet light emitting device 100 of the first embodiment has the element covering portion 141 and the substrate covering portion 142. The element covering portion 141 has the convex shape portion PR1 protruding from the second face 120b of the ultraviolet light emitting element 120. The convex shape portion PR1 is sufficiently high, and is a curved surface different from a flat surface. Thus, light incident to the fluororesin layer 140 from the second face 120b of the ultraviolet light emitting element 120 is less likely to be reflected when emitted from the convex shape portion PR1 to the outside of the ultraviolet light emitting device 100. That is, the light extraction efficiency of this ultraviolet light emitting device 100 is high.

[0067] 6. Modified Example 6-1. Fluororesin Layer (One)

[0068] Figure 7 is a schematic configuration view of an ultraviolet light emitting device 200 in a modified example of the first embodiment. As shown, an element covering portion 141 is formed on the second face 120b of the ultraviolet light emitting element 120, and a substrate covering portion 142 is formed on the mounting face 110a of the substrate 110. Thus, the inside of the vacuum heating device is returned to the atmospheric pressure while maintaining the heating temperature. From the reduced pressure heating process to the pressure restoration process, the fluororesin sheet F1 and the fluororesin film F2 are fixed to the ultraviolet light emitting element 120 and the substrate 110. Figure 7As shown, the ultraviolet light-emitting device 200 includes a substrate 110, an ultraviolet light-emitting element 120, a bonding layer 130, and a fluororesin layer 240. The fluororesin layer 240 includes an element covering portion 241 and a substrate covering portion 242. The element covering portion 241 includes a first layer 241a and a second layer 241b. The first layer 241a is formed from a fluororesin sheet F1. The second layer 241b is formed from a fluororesin film F2. The fluororesin sheet F1 and the fluororesin film F2 are made of different fluororesins. The melting point of the fluororesin sheet F1 is higher than that of the fluororesin film F2. Therefore, the fluororesin sheet F1 does not melt within the vacuum heating device and remains as the first layer 241a. In other words, the first layer 241a and the second layer 241b do not fuse. The first layer 241a covers the second surface 120b of the ultraviolet light-emitting element 120. The second layer 241b covers the side surface 120c of the ultraviolet light-emitting element 120 and the first layer 241a.

[0069] 6-2. Fluororesin layer (Part 2)

[0070] Figure 8 FIG is a schematic structural diagram of an ultraviolet light emitting device 300 in a modified example of the first embodiment. Figure 8 As shown, the ultraviolet light-emitting device 300 includes a substrate 110, an ultraviolet light-emitting element 120, a bonding layer 130, and a fluororesin layer 340. The fluororesin layer 340 includes an element covering portion 341 and a substrate covering portion 342. The element covering portion 341 includes a first layer 341a and a second layer 341b. The first layer 341a is a layer derived from the fluororesin sheet F1. The second layer 341b is a layer derived from the fluororesin film F2. The fluororesin sheet F1 and the fluororesin film F2 are made of different fluororesins. Inside the vacuum heating device, the fluororesin sheet F1 and the fluororesin film F2 melt. Then, the fluororesin sheet F1 becomes the dome-shaped first layer 341a, and the fluororesin film F2 becomes the second layer 341b covering the first layer 341a. The first layer 341a and the second layer 341b are fused. Here, the refractive index of the first layer 341a only needs to be greater than the refractive index of the second layer 341b.

[0071] 6-3. Fluororesin layer (part 3)

[0072] Figure 9 FIG is a schematic structural diagram of an ultraviolet light emitting device 400 in a modified example of the first embodiment. Figure 9As shown, the ultraviolet light emitting device 400 has the substrate 110, the ultraviolet light emitting element 120, the bonding layer 130, and the fluororesin layer 440. The fluororesin layer 440 has an element covering portion 441 and a substrate covering portion 442. The element covering portion 441 has a first layer 441a and a second layer 441b. The first layer 441a is a layer derived from the fluororesin sheet Fl. The second layer 441b is a layer derived from the fluororesin film F2. The fluororesin sheet Fl and the fluororesin film F2 are different fluororesins. The second layer 441b covers the side surface 120c of the ultraviolet light emitting element 120. Here, the width of the fluororesin sheet Fl is larger than the width Wl of the ultraviolet light emitting element 120. Therefore, when the fluororesin sheet Fl is melted, the side surface 120c of the ultraviolet light emitting element 120 is covered.

[0073] 6-4. Material

[0074] The material of the fluororesin layer 140 is, for example, FEP, PFA, PTFE, ETFE, PVDF, PCTFE, or ECTFE.

[0075] 6-5. Film thickness of fluororesin film

[0076] The film thickness of the fluororesin film F2 can also be thicker than the film thickness of the fluororesin sheet Fl.

[0077] 6-6. Air layer

[0078] The air layer 150 can also be filled by underfilling.

[0079] 6-7. Combination

[0080] The above-described modifications can also be freely combined.

[0081] (Evaluation Test) 1. Production of Samples

[0082] Three kinds of samples were produced. Sample 1 was a light emitting device in which only the ultraviolet light emitting element 120 was mounted on the substrate 110. Sample 2 was a light emitting device in which the ultraviolet light emitting element 120 of Sample 1 was covered with a fluororesin film of FEP. Sample 3 was a light emitting device in which the fluororesin sheet Fl of FEP was loaded on Sample 1, the fluororesin film F2 of FEP was loaded thereon and melted. In Sample 3, the fluororesin layer directly above the ultraviolet light emitting element 120 was raised in a lens shape.

[0083] 2. Test Results

[0084] Table 1 is a table showing the test results. In addition, the luminance was normalized by the luminance of Sample 1. As shown in Table 1, Sample 3, which corresponds to the ultraviolet light emitting device 100 of the first embodiment, was about 20% brighter than Sample 1 without the fluororesin film. Sample 3 was about 10% brighter than Sample 2.

[0085] [Table 1]

[0086]

[0087] (Notes)

[0088] The ultraviolet light emitting device in the first aspect has a substrate, an ultraviolet light emitting element, and a fluororesin layer. The substrate has a mounting surface. The ultraviolet light emitting element has a first surface having an electrode, a second surface on the opposite side of the first surface, and a side surface. The electrode of the first surface of the ultraviolet light emitting element is joined to the mounting surface of the substrate. The fluororesin layer has an element covering portion covering the second surface of the ultraviolet light emitting element, and a substrate covering portion covering the mounting surface of the substrate. The substrate covering portion has a flat portion having a flat surface on the opposite side of the mounting surface. A distance from a point in the element covering portion farthest from the second surface of the ultraviolet light emitting element to the second surface of the ultraviolet light emitting element is 1.3 times or more and 5 times or less of a distance from a flat surface of the flat portion of the substrate covering portion to the mounting surface of the substrate.

[0089] In the ultraviolet light emitting device in the second aspect, the element covering portion has a first layer covering the second surface of the ultraviolet light emitting element, and a second layer covering the first layer. The first layer and the second layer are fluororesin.

[0090] In the ultraviolet light emitting device in the third aspect, the first layer and the second layer are fused.

[0091] In the ultraviolet light emitting device in the fourth aspect, the first layer and the second layer are not fused.

[0092] In the manufacturing method of the ultraviolet light emitting device in the fifth aspect, a fluororesin sheet is placed on the second surface of the ultraviolet light emitting element having the first surface mounted to the substrate, a fluororesin film is placed on the fluororesin sheet, and the fluororesin film is fused by heating under reduced pressure to fix the fluororesin film to the ultraviolet light emitting element and the substrate.

[0093] In the manufacturing method of the ultraviolet light emitting device in the sixth aspect, the fluororesin sheet and the fluororesin film are the same material. When the fluororesin film is fused, the fluororesin sheet is fused and the fluororesin sheet and the fluororesin film are fused.

[0094] In the manufacturing method of the ultraviolet light emitting device in the seventh aspect, the fluororesin sheet and the fluororesin film are different materials. When the fluororesin film is fused, the fluororesin sheet is not fused.

[0095] In the manufacturing method of the ultraviolet light emitting device in the eighth aspect, the fluororesin sheet and the fluororesin film are different materials. When the fluororesin film is fused, the fluororesin sheet is fused and the fluororesin sheet and the fluororesin film are fused.

Claims

1. An ultraviolet light emitting device, characterized in that: It has a substrate, an ultraviolet light emitting element and a fluororesin layer, The substrate has a mounting surface, The ultraviolet light emitting element includes: a first surface having an electrode, a second surface opposite to the first surface, and a side surface. The electrode on the first surface of the ultraviolet light emitting element is bonded to the mounting surface of the substrate. The fluororesin layer has: an element covering portion, covering the second surface of the ultraviolet light emitting element; and a substrate covering portion covering the mounting surface of the substrate, The substrate covering portion has a flat portion having a flat surface located on the opposite side of the mounting surface. The distance from the point of the element covering portion that is farthest from the second surface of the ultraviolet light emitting element to the second surface of the ultraviolet light emitting element is not less than 1.3 times and not more than 5 times the distance from the flat surface of the flat portion of the substrate covering portion to the mounting surface of the substrate. The component covering portion has: a first layer covering the second surface of the ultraviolet light emitting element; and The second layer covers the first layer, The first layer and the second layer are made of fluororesin. The substrate covering portion is formed of only the second layer of the first layer and the second layer, The second layer directly covers the side surface of the ultraviolet light emitting element.

2. The ultraviolet light emitting device according to claim 1, characterized in that The first layer and the second layer are fused.

3. The ultraviolet light emitting device according to claim 1, characterized in that The first layer and the second layer are not fused.

Images