JP2023083387A - Light-emitting device - Google Patents

Abstract

To provide a light-emitting device which reduces color shading and light emission irregularity while suppressing conversion efficiency of a phosphor part from decreasing.SOLUTION: A light-emitting device according to the present invention comprises a semiconductor laser element 10, a light reflection part 20 provided with a light reflection surface 21, and a phosphor part 30 having a light irradiation surface. A region, irradiated with radiant light, of the light reflection surface 21 has a first region 21a and a second region 21b, which are so provided that on the light irradiation surface of the phosphor part 30, radiant light, reflected on a side close to the second region 21b, of radiant light reflected in the first region 21a and radiant light, reflected on a side far away from the first region 21a, of radiant light reflected in the second region 21b overlap each other and radiant light, reflected on a side far away from the second region 21b, of the radiant light reflected in the first region 21a and radiant light, reflected on a side close to the first region 21a, of the radiant light reflected in the second region 21b overlap each other.SELECTED DRAWING: Figure 5

Description

The present invention relates to light emitting devices.

The light emitting device described in Patent Document 1 includes a semiconductor laser element, a mirror member having a total reflection film formed thereon, and a fluorescent portion arranged above the mirror member. The emitted light from the semiconductor laser element is reflected by the total reflecting mirror provided on the mirror member to the fluorescent portion (see, for example, FIG. 3 of Patent Document 1).

JP 2010-251686

In such a light-emitting device, the light intensity of the radiated light applied to the light-irradiating surface of the fluorescent portion is higher in the central portion than in the surroundings. In this case, the amount of heat generated by the fluorescent portion irradiated with the central portion of the radiated light increases, which may reduce the conversion efficiency of the fluorescent portion. In addition, there is a possibility that unevenness in emission intensity and color of light extracted from the fluorescent portion may occur.

A light emitting device according to an aspect of the present invention comprises a semiconductor laser element, a light reflecting portion having a light reflecting surface, a recess in which the semiconductor laser element and the light reflecting portion are arranged, and a semiconductor laser element surrounding the recess. and a substrate having an upper surface positioned above the light reflecting portion, and a first wiring portion and a second wiring portion provided on the upper surface, wherein the semiconductor laser element emits light in a first direction. The light reflecting portion is arranged at a position away from the semiconductor laser element in the first direction when viewed from the top, and the first wiring portion and the second wiring portion are located further from the semiconductor laser element than the semiconductor laser element when viewed from the top. The light-emitting devices are arranged side by side in a second direction perpendicular to the first direction at positions spaced apart in a direction opposite to the first direction.

FIG. 1 is a perspective view of a light emitting device according to the first embodiment. FIG. 2 is a top view of the light emitting device according to the first embodiment. FIG. 3 is a cross-sectional view along III--III in FIG. 4 is a perspective view of an optical element included in the light emitting device according to the first embodiment. FIG. FIG. 5 illustrates the movement of radiated light emitted from the semiconductor laser element in the light emitting device according to the first embodiment, from being reflected by the light reflecting surface to being irradiated to the light irradiating surface of the fluorescent portion. It is a diagram for FIG. 6 is a graph obtained by simulating and measuring the light intensity distribution of radiation reflected by a conventional light reflecting surface. FIG. 7 is a diagram showing the light intensity distribution on the straight line connecting VII-VII in FIG. FIG. 8 is a perspective view for explaining the inside of the concave portion of the base in the light emitting device according to the first embodiment. FIG. 9 is a top view for explaining the inside of the concave portion of the base in the light emitting device according to the first embodiment. FIG. 10 is a diagram obtained by simulating and measuring the light intensity distribution of emitted light on the light irradiation surface of the fluorescent portion in the light emitting device according to the first embodiment. FIG. 11 is a diagram showing the light intensity distribution on the straight line connecting XI-XI in FIG. FIG. 12 is a diagram obtained by simulating and measuring the light intensity distribution of radiation light reflected by the first region on the light irradiation surface of the fluorescent portion in the light emitting device according to the first embodiment. FIG. 13 is a diagram showing the light intensity distribution on the straight line connecting XIII-XIII in FIG. FIG. 14 is a diagram obtained by simulating and measuring the light intensity distribution of the emitted light reflected by the second region on the light irradiation surface of the fluorescent portion in the light emitting device according to the first embodiment. FIG. 15 is a diagram showing the light intensity distribution on the straight line connecting XV-XV in FIG. FIG. 16 is a diagram obtained by simulating and measuring the light intensity distribution of radiation light reflected by the third region on the light irradiation surface of the fluorescent portion in the light emitting device according to the first embodiment. FIG. 17 is a diagram showing the light intensity distribution on the straight line connecting XVII-XVII in FIG. FIG. 18 is a cross-sectional view for explaining the light emitting device according to the second embodiment. FIG. 19 is a perspective view for explaining the inside of the concave portion of the base in the light emitting device according to the third embodiment. FIG. 20 is a top view for explaining the inside of the concave portion of the base in the light emitting device according to the third embodiment. FIG. 21 is a graph obtained by simulating and measuring the light intensity distribution of emitted light on the light irradiation surface of the fluorescent portion in the light emitting device according to the third embodiment. FIG. 22 illustrates movement of radiated light emitted from a semiconductor laser element in a light-emitting device according to a fourth embodiment, from being reflected by a light reflecting surface to being irradiated to a light-irradiating surface of a fluorescent portion. It is a diagram for FIG. 23 illustrates movement of radiated light emitted from a semiconductor laser element in a light-emitting device according to a fifth embodiment, from being reflected by a light reflecting surface to being irradiated onto a light irradiation surface of a fluorescent portion. It is a diagram for

A mode for carrying out the present invention will be described below with reference to the drawings. However, the embodiments shown below are for embodying the technical idea of the present invention, and do not limit the present invention. Note that the sizes and positional relationships of members shown in each drawing may be exaggerated for clarity of explanation.

<First embodiment>
FIG. 1 shows a perspective view of the light emitting device 200 according to the first embodiment, FIG. 2 shows a top view of the light emitting device 200, and FIG. 3 shows a cross-sectional view taken along line III--III of FIG. 4 is a perspective view of the optical element 20 which is the light reflecting portion 20 in the light emitting device 200. FIG. Further, FIG. 5 is for explaining the movement of the emitted light emitted from the semiconductor laser element 10 in the light emitting device 200 until it is reflected by the light reflecting surface 21 and applied to the light emitting surface of the fluorescent portion 30. As shown in FIG. is a diagram.

As shown in FIGS. 1 to 5, the light emitting device 200 includes a semiconductor laser element 10 having an elliptical far field pattern (hereinafter referred to as "FFP (Far Field Pattern)") of emitted light, and a semiconductor laser element 10 that reflects the emitted light. and a light irradiation surface onto which the radiation light reflected by the light reflection surface 21 is irradiated. When the light irradiation surface is irradiated with the radiation light, fluorescence is generated. and a fluorescent part 30 that emits light. In the light-emitting device 200, the area irradiated with the emitted light on the light reflecting surface 21 is a first area 21a corresponding to an area located at one end of the areas obtained by dividing the elliptical FFP into two or more areas in the longitudinal direction; and a second region 21b corresponding to the region located at the other end. In addition, the first region 21a and the second region 21b, on the light irradiation surface of the fluorescent part 30, are the radiation light reflected on the side closer to the second region 21b of the radiation light reflected by the first region 21a, The emitted light reflected on the far side from the first region 21a of the emitted light reflected by the second region 21b overlaps with the emitted light reflected on the far side from the first region 21a. The radiation light reflected on the far side and the radiation light reflected on the side closer to the first region 21a of the radiation light reflected by the second region 21b are provided so as to overlap each other.

According to the light emitting device 200 , it is possible to reduce unevenness in emission intensity and color of the light extracted from the fluorescent portion 30 while reducing deterioration in the conversion efficiency of the fluorescent portion 30 . This point will be described below.

Emitted light from a semiconductor laser element 10 (hereinafter referred to as an "LD (Laser Diode) element 10") travels along a plane parallel to the light-emitting surface of the LD element 10 along the stacking direction of a plurality of semiconductor layers including an active layer. It has an elliptical FFP whose length is longer than the length in the direction perpendicular to it. The FFP here is a measurement of the light intensity distribution of the emitted light on a plane parallel to the light exit surface of the LD element 10, which is some distance away from the light exit surface. e is specified as the shape at an intensity that falls to an arbitrary intensity such as ² . At this time, the emitted light has a higher intensity at the center of the ellipse than at portions far from the center of the ellipse. In a conventional light emitting device, for example, radiation light emitted from an LD element is reflected by a light reflection surface inclined at 45 degrees, and the light irradiation surface of the fluorescent portion is irradiated with the reflected light. In this case, the light irradiation surface of the fluorescent portion is irradiated while maintaining the light intensity distribution of the FFP. This is also clear from the results of simulating and measuring the light intensity distribution of the light irradiation surface in the conventional light emitting device shown in FIGS. FIG. 7 is a diagram showing the light intensity distribution on the straight line connecting VII-VII in FIG. 6, and the light intensity at the center is clearly higher than the light intensity at the ends. When the fluorescent part is irradiated with this light, the amount of heat generated by the fluorescent part in a region of high light intensity is greater than the amount of heat generated in the surrounding area, resulting in a decrease in the conversion efficiency of the fluorescent part. Moreover, due to the difference in the intensity of the radiated light with which the fluorescent portion is irradiated, there is a possibility that the light emitting device will have uneven emission intensity and color unevenness.

Therefore, in the light-emitting device 200 , the area irradiated with the radiated light on the light reflecting surface 21 is adjusted so that the radiated light reflected by the light reflecting surface 21 approaches a uniform light intensity distribution on the light irradiation surface of the fluorescent portion 30 . A first region 21a and a second region 21b are provided. At this time, as shown in FIG. 5, the first region 21a and the second region 21b are radiated light having a low emission intensity among the radiated light reflected by the first region 21a (the light emitted from the first region 21a shown in FIG. 5). radiated light reflected near the left end) and radiated light with high emission intensity among the radiated light reflected by the second region 21b (radiated light reflected near the left end of the second region 21b shown in FIG. 5) , are superimposed on each other, and among the radiant light reflected by the first region 21a, the radiant light having a high emission intensity (the radiant light reflected near the right end of the first region 21a shown in FIG. 5) and the second region 21b The radiation light having a low emission intensity (radiation light reflected in the vicinity of the right end of the second region 21b shown in FIG. 5) of the reflected radiation is provided so as to overlap. As a result, the light intensity distribution of the radiated light irradiated onto the light irradiation surface of the fluorescent portion 30 can be made nearly uniform, so that the deterioration of the conversion efficiency of the fluorescent portion 30 can be reduced while reducing unevenness in emission intensity and color unevenness. can be a light emitting device.

Components of the light emitting device 200 will be described below.

(Base 40)
The base 40 is for mounting the LD element 10 thereon. In FIG. 3, a substrate 40 provided with a recess is used, and the LD element 10 is arranged on the bottom surface of the recess.

Substrates 40 that contain ceramics can be used. Ceramics include, for example, aluminum oxide, aluminum nitride, silicon nitride, or silicon carbide. When the base body 40 and the lid body 80 are fixed by welding, the portion (welded part 43) in contact with the lid body 80 is made of a material containing iron as a main component.

As shown in FIGS. 8 and 9, the substrate 40 provided with the recess includes a body portion 41 made of an insulating material, wiring portions 42a and 42b exposed from the body portion 41 on the upper surface of the substrate 40 and the bottom surface of the recess, and a welding portion 43 in contact with the lid 80 . By exposing the wiring portion 42a electrically connected to the outside from a surface other than the lower surface of the main body portion 41, the entire lower surface of the base 40 can be used as a surface to be mounted on another member such as a heat sink. Heat generated in the device 200 can be easily dissipated to the heat sink.

As the substrate, one having a base portion and a frame portion arranged on the upper surface of the base portion may be used. In this case, the LD element is arranged on the upper surface of the base and inside the frame. At this time, the wiring portion is preferably provided on the upper surface of the base portion outside the frame portion in consideration of the heat dissipation of the light emitting device.

(Semiconductor laser element 10)
The LD element 10 has an FFP whose emitted light is elliptical. The LD element 10 is arranged such that its light emitting surface is perpendicular to the lower surface of the substrate 40 and the longitudinal direction of the elliptical shape of the FFP is perpendicular to the lower surface of the substrate 40 . As a result, the large surface of the LD element 10 can be arranged parallel to the lower surface of the base 40, so that the heat generated in the LD element 10 can be easily dissipated to the base 40 and the heat sink. It should be noted that the term “perpendicular” here includes the inclination due to the degree of misalignment during mounting.

As the LD element 10, one having an emission peak wavelength in the range of 320 nm to 530 nm, typically in the range of 430 nm to 480 nm can be used. Since the LD element 10 within the range described above emits light with relatively high energy, the conversion efficiency of the fluorescent portion 30 is likely to decrease, and the effect of adopting the light reflecting surface 21 and the like of the present embodiment is remarkable. It is for the sake of becoming. As the LD element 10 within the range described above, for example, it is preferable to use a material containing a nitride semiconductor, and examples include those containing at least one of GaN, InGaN, and AlGaN.

The LD element 10 is mounted on the base 40 via the submount 50 . As a result, the distance from the light emitting point on the light emitting surface of the LD element 10 to the mounting surface of the LD element 10 on the substrate 40 (the bottom surface of the recess in the light emitting device 200) can be increased by the thickness of the submount 50. The light radiated from the LD element can be efficiently irradiated onto the light reflecting surface 21 . The LD element 10 can be fixed to the submount 50 using a conductive layer 60 such as Au--Sn.

Submount 50 preferably has a thermal expansion coefficient between that of substrate 40 and that of LD element 10 . As a result, peeling of the LD element 10 and peeling of the submount 50 can be suppressed. When a material containing a nitride semiconductor is used for the LD element 10, the submount 50 is made of aluminum nitride or silicon carbide, for example.

As shown in FIGS. 8 and 9, the LD element 10 is electrically connected to the wiring portion 42b of the substrate 40 by a wire (thin metal wire) 70. As shown in FIG.

(Light reflecting portion 20)
The light reflecting section 20 reflects the emitted light from the LD element 10 toward the fluorescent section 30 . As in the light emitting device 200, the light emitted from the LD element 10 is reflected by the light reflecting portion 20, thereby reducing the thickness of the light emitting device 200 (length in the vertical direction in FIG. 3) compared to the case of using a transmissive lens. The intensity of the radiated light with which the light-irradiated surface of the fluorescent portion 30 is irradiated can be made nearly uniform while reducing the height).

In FIG. 3, an optical element 20 having a light reflecting surface 21 on at least one surface is used as the light reflecting portion 20 . By separating the base 40 and the optical element 20, the structure of the base 40 can be simpler than when a part of the base functions as a light reflecting surface. The base can also be configured such that a part of the base functions as a light reflecting surface. In this case, since it is not necessary to consider the area in which the collet for arranging the optical element moves, the width of the concave portion of the base can be reduced.

In this specification, all surfaces other than the upper and lower surfaces of the optical element 20 are side surfaces. In the light emitting device 200, one of the four side surfaces of the optical element 20, which is closer to the LD element 10, serves as a light reflecting surface 21, as shown in FIGS. By using the side surface closer to the LD element 10 as the light reflecting surface 21, the number of interfaces through which the emitted light passes can be reduced compared to the case where the side surface farther from the LD element 10 is used as the light reflecting surface. , the absorption of light in the optical element can be suppressed.

As the optical element 20, the main material is made of quartz or glass such as BK7, or a heat-resistant material such as metal such as aluminum, and the light reflecting surface 21 is made of a highly reflective material such as metal. can.

In the light-emitting device 200, the light reflecting surface 21 is provided so that only the light intensity distribution in the longitudinal direction of the elliptical shape irradiated to the light irradiation surface is nearly uniform. In other words, the light reflecting surface 21 is provided such that the light intensity distribution in the longitudinal direction approaches uniformity without changing the light intensity distribution in the lateral direction. This is because the FFP of the LD element 10 tends to spread particularly in the longitudinal direction. It should be noted that the light reflecting surface can be made such that the light intensity distribution in the lateral direction is also nearly uniform. It is preferable that only the light intensity distribution in the longitudinal direction of the elliptical shape on the light irradiation surface is provided so as to approach uniformity.

As shown in FIG. 4, the area of the light reflecting surface 21 irradiated with the radiation light (the area surrounded by the dashed line) is the area obtained by dividing the elliptical FFP of the LD element 10 into two or more in the longitudinal direction. Among them, it has a first region 21a corresponding to the region located at one end and a second region 21b corresponding to the region located at the other end. Then, as shown in FIG. 4, the first region 21a and the second region 21b are composed of the radiation light reflected on the side closer to the second region 21b of the radiation reflected by the first region 21a and the second region 21b. The radiation light reflected on the side far from the first region 21a of the radiation reflected by the region 21b overlaps with the radiation light reflected on the side far from the first region 21a, and the radiation light reflected on the first region 21a on the side far from the second region 21b and the radiation light reflected on the side closer to the first region 21a out of the radiation light reflected by the second region 21b are provided so as to overlap each other.

Here, the first region 21a and the second region 21b are respectively the light intensity distribution of the radiation light reflected by the first region 21a and the light intensity distribution of the radiation light reflected by the second region 21b on the light irradiation surface of the fluorescent section 30. The light intensity distribution is provided so as to be line symmetrical with respect to the direction corresponding to the longitudinal direction. That is, on the light irradiation surface, the first region 21a and the second region 21b are provided so as to overlap each other with the same width. This makes it easier to make the light intensity distribution on the light irradiation surface nearly uniform.

For example, as shown in FIG. 5, the area of the first region 21a located closer to the LD element 10 than the second region 21b is made smaller than the area of the second region 21b. Since the first region 21a located closer to the LD element 10 has a longer distance to the light irradiation surface of the fluorescent portion 30 and the emitted light tends to spread, the first region 21a and the second region 21b are overlapped with the same width. easier.

In the light emitting device 200, the area irradiated with the radiation light on the light reflecting surface 21 has the third area 21c located between the first area 21a and the second area 21b. As shown in FIG. 5 , the third region 21c includes, on the light irradiation surface of the fluorescent portion 30, the radiation light reflected on the side closer to the first region 21a of the radiation light reflected by the third region 21c, Of the radiation reflected by the first region 21a, the radiation reflected on the far side from the second region 21b overlaps, and of the radiation reflected by the third region 21c, the radiation is reflected in the second region 21b. The radiation light reflected on the near side and the radiation light reflected on the far side from the first region 21a of the radiation light reflected by the second region 21b are provided so as to overlap each other. That is, light with low emission intensity among the emitted light reflected by the third region 21c (light reflected near the left end and near the right end of the third region 21c in FIG. 5), the first region 21a and the second region Overlapping light with high emission intensity among the emitted light reflected by 21b (light reflected near the right end of the first region 21a and light reflected near the left end of the second region 21b in FIG. 5) can be done. When the light reflecting surface 21 has the third region 21c, it is possible to suppress the spread of the light reflected by the light reflecting surface 21 compared to the case where the light reflecting surface 21 consists only of the first region 21a and the second region 21b. Even if the distance from the light reflecting surface 21 to the light irradiation surface of the fluorescent portion 30 is increased, there is no need to lengthen the longitudinal direction of the light irradiation surface of the fluorescent portion 30 . The area irradiated with the radiation light on the light reflecting surface 21 may have four or more areas.

The first region 21a, the second region 21b, and the third region 21c, in the longitudinal direction of the FFP, the divergence angle of the emitted light reflected by the first region 21a and the second region 21b is reflected by the third region 21c. It is provided so as to be smaller than the divergence angle of the emitted light. That is, in the longitudinal direction of the elliptical FFP, the light with high emission intensity from the third region 21c spreads outward, and the light on the side of the first region 21a and the second region 21b farther from the third region 21c is suppressed from spreading. is provided with a light reflecting surface 21 . This makes it possible to make the light intensity distribution nearly uniform while suppressing the spread of the radiated light irradiated onto the light irradiation surface.

As shown in FIG. 4, the first region 21a, the second region 21b, and the third region 21c are all flat. That is, the light reflecting surface 21 is composed of three planes. This facilitates the design of the optical element 20 . In addition, the first area, the second area, and the third area may each be a curved surface.

FIG. 10 shows a diagram obtained by simulating and measuring the light intensity distribution of emitted light on the light irradiation surface of the fluorescent portion 30 of the light emitting device 200, and FIG. 11 is a diagram showing the light intensity distribution on the straight line connecting XI-XI in FIG. indicates FIG. 12 shows a diagram obtained by simulating and measuring the light intensity distribution of the radiated light reflected by the first region 21a on the light irradiation surface of the fluorescent part 30, and FIG. A diagram representing the distribution is shown. FIG. 14 shows a diagram obtained by simulating and measuring the light intensity distribution of the radiated light reflected by the second region 21b on the light irradiation surface of the fluorescent portion 30, and FIG. A diagram representing the distribution is shown. FIG. 16 shows a diagram obtained by simulating and measuring the light intensity distribution of the radiated light reflected by the third region 21c on the light irradiation surface of the fluorescent part 30, and FIG. A diagram representing the distribution is shown. The simulation conditions will be described below with reference to FIG. The distance from the light emitting point of the LD element 10 to the light reflecting surface (more precisely, the light reflecting point) of the light reflecting surface 21 in the direction parallel to the lower surface of the optical element 20 and the lower surface of the LD element 10 is 0.45 mm. The distance from the light reflection point of the light reflection surface 21 to the light irradiation surface of the fluorescent portion 30 in the direction perpendicular to the lower surface of the fluorescent portion 20 was set to 2.10 mm. At this time, between the light reflecting point and the fluorescent portion 30, the translucent portion 82 with a thickness of 0.5 mm and the radiator 100 with a thickness of 0.43 mm are arranged. The width of the light irradiation surface of the fluorescent portion 30 in the longitudinal direction (the length in the direction parallel to the rectilinear direction from the light emitting point to the light reflecting point) was set to 1 mm, and the width in the short direction was set to 0.5 mm. Furthermore, the angle between the lower surface of the optical element 20 and the first region 21a is 31.5 degrees, the angle between the lower surface of the optical element 20 and the second region 21b is 60 degrees, and the lower surface of the optical element 20 and the third region 21c are The angle between the two was set to 45 degrees. At this time, the length L1 of the first region was 0.14 mm, the length L2 of the second region 21b was 0.36 mm, and the length L3 of the third region 21c was 0.27 mm. As shown in FIG. 11, according to the light emitting device 200, the light intensity distribution of the radiated light on the light irradiation surface of the fluorescent portion 30 can be made nearly uniform.

(Lid body 80)
The lid 80 is combined with the base 40 to form a hermetically sealed space in which the LD element 10 is arranged. As a result, it is possible to suppress collection of dust such as organic matter on the light emitting surface of the LD element 10 . The lid body 80 has a support portion 81 , a light-transmitting portion 82 , and a bonding material 83 that bonds the support portion 81 and the light-transmitting portion 82 . The light reflected by the light reflecting surface 21 passes through the translucent portion 82 and is irradiated onto the light irradiation surface of the fluorescent portion 30 .

In the light-emitting device 200, since the LD element 10 is made of a material containing a nitride semiconductor, the supporting portion 81 of the lid 80 and the base 40 are fixed by welding. In this case, a material containing iron as a main component can be used for the support portion 81 . Further, in the light emitting device 200, the LD element 10 and the optical element 20 are arranged in one space hermetically sealed by the base 40 and the lid 80. As shown in FIG. As a result, it is possible to prevent the light-emitting device 200 from becoming larger than a light-emitting device including an LD device on which an LD element is mounted and an optical element arranged outside the LD device. Glass or sapphire, for example, is used as the light-transmitting portion 82 , and low-melting-point glass or gold-tin solder, for example, is used as the bonding material 83 .

(Fluorescent part 30)
The fluorescent part 30 has a light irradiation surface irradiated with the radiation light reflected by the light reflecting surface 21, and emits fluorescence when the light irradiation surface is irradiated with the radiation light. In FIG. 3, the lower surface of the fluorescent portion 30 is the light irradiation surface, and the upper surface of the fluorescent portion 30 is the light extraction surface. As shown in FIG. 3 , the fluorescent portion 30 is arranged above the translucent portion 82 of the lid 80 .

The fluorescent portion 30 contains a fluorescent substance. Examples of phosphors include YAG phosphors, LAG phosphors, α-sialon phosphors, and the like. Among them, it is preferable to use a YAG phosphor having high heat resistance. The fluorescent part 30 is preferably made of an inorganic material. This makes it more resistant to heat and light than when it contains an organic material, so reliability can be improved. As the phosphor portion 30 made of an inorganic material, phosphor ceramics or a phosphor single crystal can be used. A sintered body of phosphor particles and an additive can be used as the phosphor ceramic. When phosphor ceramics of YAG phosphor are used, aluminum oxide can be used as an additive.

As shown in FIGS. 2 and 3, the light irradiation surface of the fluorescent portion 30 preferably has a shape elongated in one direction. For example, an elliptical shape or a rectangular shape can be used, and a rectangular shape is preferable from the viewpoint of mass production of the fluorescent portion 30 . At this time, the radiant light reflected by the light reflecting surface 21 is irradiated on the light irradiation surface of the fluorescent section 30 in a shape elongated in one direction, and the fluorescent section 30 and the semiconductor laser element 10 are aligned in the longitudinal direction of the fluorescent section 30 and the radiated light. is preferably arranged so that the longitudinal direction of the As a result, the distance from the area on the light-irradiated surface of the fluorescent portion 30 to which the emitted light hits to the outer edge of the light-irradiated surface is reduced, so that the heat generated in the fluorescent portion 30 can be easily dissipated. Therefore, it becomes easy to reduce the deterioration of the conversion efficiency of the fluorescent portion 30 .

(First light shielding part 90)
The first light shielding part 90 is for reducing the emission of light from a region other than the upper surface of the fluorescent part 30, and is arranged on the side of the fluorescent part 30 as shown in FIG. The first light shielding portion 90 is provided in direct contact with the fluorescent portion 30 . When the fluorescent portion 30 contains YAG fluorescent material, it is preferable to use ceramics containing aluminum oxide as a main component as the first light shielding portion 90 . As a result, the light from the fluorescent portion 30 can be blocked while increasing the bonding strength between the fluorescent portion 30 and the first light blocking portion 90 . The aluminum oxide used for the first light shielding part 90 is the same material as sapphire that can be used for the radiator 100 described later, but the region of the first light shielding part 90 near the fluorescent part 30 has a low sintering density. Therefore, voids exist in that region. Even if the material is the same, the light from the fluorescent portion 30 is reflected at the interface between the particles of aluminum oxide or the like and the voids, so the first light shielding portion 90 is difficult to transmit light.

(Radiator 100)
As shown in FIG. 3 , the fluorescent portion 30 and the first light shielding portion 90 are fixed to the lid 80 via the radiator 100 . It is preferable that the upper surface of the radiator 100 and the light irradiation surface of the fluorescent section 30 and the lower surface of the first light shielding section 90 are in direct contact with each other. As a result, the heat radiator 100 can be brought into direct contact with the region of the fluorescent portion 30 that is likely to generate heat when irradiated with the emitted light, so that the heat generated in the fluorescent portion 30 can be easily dissipated. A translucent member can be used as the radiator 100, and for example, sapphire, quartz, or silicon carbide can be used. The fluorescent part 30 may be arranged above the light reflecting surface by fixing the first light shielding part 90 and the radiator 100 with a heat-resistant metal material or the like.

(Second light shielding part 110)
A second light shielding portion 110 is provided on the side surface of the radiator 100 . As a result, it is possible to suppress the escape of light from the sides of the radiator 100 . As the second light shielding part 110, for example, a resin containing scattering particles such as titanium oxide is used.

<Second embodiment>
FIG. 18 shows a cross-sectional view of a light emitting device 300 according to the second embodiment. The light emitting device 300 is substantially the same as the light emitting device 200 except for the items described below.

In the light emitting device 300 , the light reflecting surface of the optical element 20 is provided on the side surface farther from the LD element 10 . That is, the emitted light enters the optical element 20 from the side surface of the optical element 20 closer to the LD element 10 , is reflected by the light reflecting surface 21 , and is extracted from the upper surface of the optical element 20 . Even in this case, the light intensity of the radiated light irradiated on the light irradiation surface of the fluorescent portion 30 can be made nearly uniform. At this time, as the optical element 20, the main material is made of quartz or glass such as BK7, and the light reflecting surface is made of a highly reflective material such as metal.

<Third Embodiment>
FIG. 19 shows a perspective view for explaining the inside of the concave portion of the base 40 in the light emitting device 400 according to the third embodiment, and FIG. 20 shows a top view of FIG. The light emitting device 400 is substantially the same as the light emitting device 200 except for the items described below.

Light emitting device 400 includes two LD elements 10 and two optical elements 20 . The optical elements 20 are arranged so that the radiation light emitted from each LD element 10 is reflected by the light reflection surface 21 of each optical element 20 and is irradiated onto the light irradiation surface of one fluorescent portion 30 . ing. Specifically, the two LD elements 10 are arranged so that their light exit surfaces are parallel, and the two optical elements 20 are arranged so that their facing side surfaces are parallel. A plane parallel to the side surface of the optical element 20 and a plane parallel to the light emitting surface of the LD element 10 are arranged to intersect at an angle other than perpendicular.

FIG. 21 shows a diagram obtained by simulating and measuring the light intensity distribution of the radiated light irradiated onto the light irradiation surface of the fluorescent portion 30 in the light emitting device 400 . As shown in FIG. 21, by using a plurality of LD elements 10, it is possible to increase the intensity of the radiated light with which the light irradiation surface of the fluorescent section 30 is irradiated.

Also in this embodiment, the two opposing side surfaces of the concave portion of the substrate may be used as light reflecting surfaces, and the light emitted from the LD element may be applied to each of the two light reflecting surfaces. Also, the optical elements used in the second embodiment can be used as the two optical elements.

<Fourth Embodiment>
FIG. 22 is a diagram of the radiation light emitted from the semiconductor laser element 10 reflected by the light reflection surface 21 and applied to the light irradiation surface of the fluorescent portion 30 in the light emitting device 500 according to the fourth embodiment. It is a figure for demonstrating a motion. The light emitting device 500 is substantially the same as the light emitting device 200 except for the items described below.

As shown in FIG. 22, in the light emitting device 500, the area irradiated with the emitted light on the light reflecting surface 21 corresponds to the area located at one end of the three areas obtained by dividing the elliptical FFP in the longitudinal direction. a first region 21a, a second region 21b corresponding to a region located at the other end, and a third region 21c located between the first region 21a and the second region 21b. At this time, the first region 21a, on the light irradiation surface of the fluorescent section 30, is the first region 21a or the second region of the radiation light reflected by the third region 21c. It is provided so as to overlap the radiation reflected on the side near one of the regions 21b. In addition, the second region 21b, on the light irradiation surface of the fluorescent section 30, is the first region 21a or the second region 21b of the radiation light reflected by the third region 21c. is provided so as to overlap the radiation reflected on the side closer to the other side. In other words, part of the emitted light reflected by the first region 21a and part of the emitted light reflected by the second region 21b are transferred to a region of low emission intensity among the emitted light reflected by the third region 21c. The first region 21a and the second region 21b are provided so as to overlap each other.

As shown in FIG. 22, in the light-emitting device 500, the first region 21a is such that the radiation light reflected by the first region 21a becomes the radiation light reflected by the third region 21c on the light irradiation surface of the fluorescent portion 30. It is provided so as to overlap the radiant light reflected on the side closer to the second region 21b. Further, the second region 21b is formed on the light irradiation surface of the fluorescent portion 30 so that the emitted light reflected by the second region 21b is closer to the first region 21a than the emitted light reflected by the third region 21c. It is provided so as to overlap with the reflected radiation. That is, the first region 21a and the second region 21a and the second regions 21a and 21b are arranged so that the light irradiation surface of the fluorescent portion 30 is irradiated after the light reflected by the first region 21a and the light reflected by the second region 21b intersect. A region 21b is provided. As a result, light with a low emission intensity (light reflected near the left end of the first region 21a in FIG. 22) among the light reflected by the first region 21a and light reflected by the third region 21c Light with low emission intensity (light reflected in the vicinity of the right end of the third region 21c in FIG. 22) can be superimposed, and light with low emission intensity (light reflected in the second region 21b in FIG. 22) can be superimposed. light reflected near the right end of the second region 21b in FIG. 22) and light with low emission intensity among the light reflected by the third region 21c (light reflected near the left end of the third region 21c in FIG. 22) can be superimposed. Therefore, it is easy to make the light intensity of the radiated light on the light irradiation surface of the fluorescent portion 30 nearly uniform.

In the light-emitting device 500, the radiation reflected by the first region and the radiation that could be reflected by the second region may not intersect. In other words, the light reflecting surface reflects the light reflected on the side closer to the first area out of the light reflected in the third area and the light reflected in the first area on the side closer to the third area. While superimposing the reflected light, the light reflected on the side closer to the second region out of the light reflected in the third region and the light reflected in the second region on the side closer to the third region It may be provided so as to overlap the emitted light. Even in this case, it is possible to superimpose the light with low emission intensity among the emitted light reflected by the third region, the light reflected by the first region, and the light reflected by the second region. A certain effect can be obtained.

<Fifth Embodiment>
FIG. 23 is a diagram of the emission light emitted from the semiconductor laser element 10 reflected by the light reflection surface 21 and applied to the light irradiation surface of the fluorescent portion 30 in the light emitting device 600 according to the fifth embodiment. It is a figure for demonstrating a motion. The light emitting device 600 is substantially the same as the light emitting device 200 except for the items described below.

In light emitting device 600, light reflecting surface 21 of optical element 20 is a curved surface. At this time, the light reflecting surface 21 is arranged so that the intensity distribution of the emitted light on the light irradiation surface of the fluorescent portion 30 approaches uniformity, and the radiation reflected by the regions corresponding to the regions located at both ends in the longitudinal direction of the elliptical FFP It is provided so that the divergence angle of light is smaller than the divergence angle of light reflected in the region corresponding to the region located in the center in the longitudinal direction. In other words, in the longitudinal direction of the elliptical FFP, the light reflection surface 21 is provided so that the light near the center spreads outward and the light near the ends suppresses the spread. Even in this case, the light intensity distribution of the radiated light on the light irradiation surface can be made nearly uniform.

The light-emitting device described in each embodiment can be used for illumination, vehicle lamps, and the like.

DESCRIPTION OF SYMBOLS 10... Semiconductor laser element 20... Light reflection part 21... Light reflection surface 21a... 1st area|region 21b... 2nd area|region 21c... 3rd area|region 30... Fluorescent part 40... Base|substrate 41... Main-body part 42a, 42b... Wiring part 43... Welding Part 50 Submount 60 Conductive layer 70 Wire 80 Lid 81 Supporting part 82 Translucent part 83 Joining material 90 First light shielding part 100 Radiator 110 Second light shielding part 200, 300, 400 , 500, 600... light-emitting device

Claims (11)

a semiconductor laser element;
a light reflecting portion having a light reflecting surface;
a concave portion in which the semiconductor laser element and the light reflecting portion are arranged; an upper surface surrounding the concave portion and positioned higher than the semiconductor laser element and the light reflecting portion; a substrate having a wiring portion, and a third wiring portion and a fourth wiring portion provided in the recess;
one or more first wires electrically connecting the semiconductor laser element to the third wiring portion;
one or more second wires electrically connecting the semiconductor laser element to the fourth wiring portion;
with
The semiconductor laser element emits light in a first direction,
The light reflecting portion is arranged at a position spaced apart in the first direction from the semiconductor laser element when viewed from above,
The first wiring portion and the second wiring portion are arranged side by side in a second direction perpendicular to the first direction at a position apart from the semiconductor laser element in a direction opposite to the first direction when viewed from above,
the first wire is joined to the third wiring portion at a position spaced apart from the semiconductor laser element in the second direction when viewed from above;
The light-emitting device, wherein the second wire is joined to the third wiring portion at a position away from the semiconductor laser element in a direction opposite to the second direction when viewed from above. Further comprising a lid bonded to the base,
The base has a welded portion surrounding the recess,
The lid body is joined to the welded portion,
When viewed from the top, the lid and the first wiring portion and the second wiring portion do not overlap,
2. The light emitting device according to claim 1, wherein the light reflected by said reflecting portion passes through said cover and is emitted upward. 3. The light-emitting device according to claim 2, wherein said weld is made of a material containing iron. The first wiring portion is provided at a position away from the second wiring portion in the second direction,
The length from the farthest position of the first wiring part from the second wiring part in the second direction to the furthest position of the second wiring part from the first wiring part in the direction opposite to the second direction is larger than the width of the recess in the second direction. 5. The light-emitting device according to claim 1, wherein said base comprises a base on which said semiconductor laser element is arranged and a frame which is arranged on said base. 6. The light emitting device according to claim 5, wherein said first wiring portion and said second wiring portion are provided at the base of said base. 7. The light emitting device according to any one of claims 1 to 6, wherein the substrate comprises aluminum nitride ceramics. 7. The light emitting device according to any one of claims 1 to 6, wherein the substrate comprises aluminum oxide ceramics. further comprising a submount to which the semiconductor laser element is fixed;
The semiconductor laser element is mounted on the base via the submount,
the one or more first wires are joined to the submount and the third wiring portion;
9. The light emitting device according to claim 1, wherein said one or more second wires are joined to said semiconductor laser element and said fourth wiring portion. comprising a plurality of the first wires and a plurality of the second wires,
10. The light emitting device according to claim 9, wherein the number of said second wires is greater than the number of said first wires. At least a portion of the first wiring portion and at least a portion of the second wiring portion pass through one end of both ends of the recess in the second direction and are parallel to the first direction when viewed from above. The light-emitting device according to any one of claims 1 to 10, arranged between a straight line and an imaginary straight line passing through the other end of the two ends and parallel to the first direction.

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