JP2017188651A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device capable of achieving miniaturization, higher luminance, and improved heat dissipation.SOLUTION: The light-emitting device includes: a substrate; a laser element arranged on a mounting surface of the substrate; a fluorescent member which has a first main surface and a second main surface opposite to each other and of which the second main surface side is fixed to the mounting surface of the substrate; a first optical member which changes the traveling direction of a laser beam emitted from the laser element to a direction toward the first main surface of the fluorescent member; and a lid which transmits light from the fluorescent member, is connected to the substrate, and seals the laser element, the fluorescent member, and the first optical member.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a light emitting device.

  2. Description of the Related Art A light emitting device that includes a laser element and a fluorescent member on a base, makes laser light incident on a side surface or an upper surface of the fluorescent member, and extracts light from the upper surface of the fluorescent member is known (for example, Patent Documents 1 and 2). .

JP 2010-251686A JP 2013-16567 A

  However, for example, in the light emitting device according to Patent Document 1, laser light is incident from the side surface of the fluorescent member, and light is extracted from the upper surface of the fluorescent member. That is, light is absorbed or scattered inside the fluorescent member before the light incident on the side surface of the fluorescent member is emitted from the upper surface of the fluorescent member, so that the light utilization efficiency is lowered.

  In the light emitting device according to Patent Document 2, a laser element is mounted on a slope of a substrate that is higher than the upper surface of the fluorescent member so that laser light is incident from the upper surface of the fluorescent member and light is extracted from the same surface. In this case, even if the lower surface of the light emitting device is connected to the heat sink, it is difficult to efficiently dissipate the heat generated in the laser element to the heat sink because there is a relatively long distance between the laser element and the heat sink. Moreover, since it is necessary to form the inclined surface of the substrate at a position higher than the upper surface of the fluorescent member, the light emitting device tends to be large. Furthermore, since the surface on which the laser element is mounted is inclined, it is difficult to mount the laser element with high accuracy.

  The present disclosure includes the following inventions. A base, a laser element disposed on the mounting surface of the base, and a first main surface and a second main surface on opposite sides, the second main surface being fixed to the mounting surface of the base A fluorescent member, a first optical member that changes a traveling direction of laser light emitted from the laser element to a direction toward the first main surface of the fluorescent member, and transmits light from the fluorescent member, A light emitting device comprising: a lid body connected and sealing the laser element, the fluorescent member, and the first optical member.

  According to the above light emitting device, the light emitting device can be reduced in size, increased in brightness, and improved in heat dissipation.

1 is a schematic plan view showing a light emitting device according to Embodiment 1. FIG. It is sectional drawing in the AA line in FIG. It is sectional drawing in the BB line in FIG. FIG. 6 is a schematic cross-sectional view showing a modification of the light emitting device according to Embodiment 1. 1 is a schematic perspective view showing a cylindrical lens according to Embodiment 1. FIG. 6 is a schematic cross-sectional view showing a light emitting device according to Embodiment 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a configuration for embodying the technical idea of the present invention, and does not specify the present invention. Furthermore, in the following description, the same name and symbol indicate the same or the same members, and detailed description thereof will be omitted as appropriate.

[Embodiment 1]
In the light emitting device 100 according to the first embodiment, as shown in FIGS. 1 to 3, the laser element 2 is disposed on the mounting surface of the base 1 and has a first main surface and a second main surface on opposite sides. 4 is fixed to the mounting surface of the base body 1 on the second main surface side. The first optical member 3 is arranged so as to change the traveling direction of the laser light emitted from the laser element 2 to a direction toward the first main surface of the fluorescent member 4. Here, the lid 5 is used to transmit light from the fluorescent member 4 and is connected to the base 1 so as to seal the laser element 2, the fluorescent member 4, and the first optical member 3.

  In the light emitting device 100, as shown in FIG. 2, the laser light emitted from the laser element 2 is changed in the traveling direction by the first optical member 3, and enters the first main surface of the fluorescent member 4 obliquely from above. In the present embodiment, a prism is used as the first optical member 3. The fluorescent member 4 is excited by incident laser light and emits light having a wavelength different from that of the laser light. This wavelength-converted light is emitted mainly upward from the first main surface, passes through the lid 5 together with a part of the reflected light reflected without exciting the fluorescent member 4, and is taken out of the light emitting device 100. Thereby, for example, white light can be extracted from the upper surface of the light emitting device 100. Here, the upper surface of the light emitting device 100 refers to the surface on the side from which light is extracted, in other words, the surface on the side where the lid 5 is provided. When the light emission of the light emitting device 100 is white light, the laser light is, for example, blue light, and the wavelength converted light is, for example, yellow light. A part of the reflected light travels inside the base body 1 without passing through the lid 5.

  The 1st optical member 3 is a member which can change the advancing direction of a laser beam. Therefore, by using the first optical member 3, the laser light is emitted from the laser element 2 in a direction in which the laser light is emitted substantially parallel to the mounting surface of the base 1, that is, so that the laser light passes above the fluorescent member 4. Even if the laser beam is emitted, the laser beam can be incident on the first main surface of the fluorescent member 4 obliquely from above. Thereby, since the height of the base 1 can be reduced as compared with, for example, the case where the surface on which the laser element 2 is disposed is inclined without using the first optical member 3, the light emitting device 100 can be reduced in size. Can do. Furthermore, since the distance between the laser element 2 and the heat sink can be shortened when the lower surface of the light emitting device 100 is connected to the heat sink, heat can be efficiently radiated.

  By irradiating the first main surface of the fluorescent member 4 obliquely from above, the laser light is emitted mainly on the surface of the fluorescent member 4 and in the vicinity thereof. The light extraction surface of the light emitting device 100 is above the fluorescent member 4. Thereby, compared with the case where the first main surface of the fluorescent member 4 irradiated with the laser light and the light extraction surface of the light emitting device 100 are not on the same surface side, the light extraction efficiency from the light emitting device 100 is improved, Brightness can be increased. In addition, since it is mainly the surface of the fluorescent member 4 and the vicinity thereof that is excited by the laser light, as compared with the case where the laser light is incident on one surface of the fluorescent member 4 and light is extracted from the other surface, Since the fluorescent member 4 can be made thin, the light emitting device 100 can be reduced in size.

  Hereinafter, each member will be described in detail.

(Laser element 2)
Although any number of various laser elements can be used for the laser element 2, the light emitting device 100 uses one GaN-based semiconductor laser element. The GaN-based semiconductor laser element can have an oscillation wavelength of, for example, 350 nm to 600 nm, preferably 430 nm to 460 nm. The output of the laser element 2 can be set to 2 W to 4 W, for example.

  The laser element 2 is preferably junction-down mounted on the mounting surface of the substrate 1. Here, junction down mounting refers to mounting the main surface of the laser element 2 closer to the active layer on the mounting surface of the substrate 1. For example, the active layer of the laser element 2 is half the thickness of the laser element 2. It means that it is mounted on the lower side. Thereby, the heat generated by the laser element 2 can be effectively radiated to the base 1.

  In the light emitting device 100, as shown in FIG. 2, the submount 7 is disposed on the mounting surface of the base 1, and the laser element 2 is disposed on the submount 7. Thereby, compared with the case where the laser element 2 is directly arranged on the mounting surface of the base body 1, the light emitting surface of the laser element 2 can be separated from the mounting surface of the base body 1. As a result, it is possible to suppress the laser light from hitting the mounting surface of the substrate 1 and to easily irradiate the laser light to the first main surface of the fluorescent member 4 from obliquely above. As the submount 7, for example, aluminum nitride or silicon carbide can be used. In the light emitting device 100, silicon carbide having high thermal conductivity is used as a submount. The thickness of the submount 7 can be set to 0.2 mm to 0.5 mm, for example. The laser element 2 can also be directly arranged on the mounting surface of the substrate 1.

(First optical member 3)
The 1st optical member 3 is a member which can change the advancing direction of a laser beam. The first optical member 3 is preferably a prism having a light incident surface 3a on which laser light is incident and a light emitting surface 3b from which laser light is emitted. The prism refers to a transparent polyhedron and is made of an inorganic material such as quartz, glass, or sapphire. In the light emitting device 100, a polygonal columnar glass is used as the first optical member 3 as shown in FIG. 2, and one surface thereof is mounted on the mounting surface of the substrate 1. Further, the first optical member 3 does not contain a phosphor or a filler. The first optical member 3 can change the traveling direction of light by refracting, totally reflecting, and / or birefringing light. For this reason, by using the first optical member 3, the traveling direction of the laser light can be easily changed to the direction toward the first main surface of the fluorescent member 4.

  When the first optical member 3 is disposed between the laser element 2 and the fluorescent member 4 when viewed from the top, the first optical member 3 includes the bottom surface of the first optical member 3 and the light of the first optical member 3. It is preferable that the exit surface 3b has an acute angle. In the light emitting device 100, the angle of the first optical member 3 is 55 degrees, but may be, for example, 50 degrees to 70 degrees. As a result, the laser light incident on the first optical member 3 can be refracted downward and emitted from the light emitting surface 3 b toward the first main surface of the fluorescent member 4. Further, by setting the angle within this range, when the fluorescent member 4 is excited and emits light upward, the light from the fluorescent member 4 hardly hits the first optical member 3, so that part of the light is the first optical member. It is possible to reduce the possibility that a shadow hits 3. As a result, a decrease in light extraction efficiency can be suppressed. Furthermore, laser light can be made incident on the fluorescent member 4 at a relatively short distance from the laser element 2. Thereby, the fall of the utilization efficiency of a laser beam can be suppressed. Further, it is possible to reduce the influence of the displacement of each member with respect to the laser light. In addition, since the laser light can enter the fluorescent member 4 at a short distance, the light emitting device 100 can be downsized.

  As shown in FIG. 1, the first optical member 3 is preferably arranged at a position that does not overlap the fluorescent member 4 in a top view. Thereby, when the fluorescent member 4 is excited and emits light upward, it is possible to reduce the possibility that a part of the light hits the first optical member 3 and is shaded. That is, with such an arrangement, the light from the fluorescent member 4 is less likely to hit the first optical member 3, so that it is possible to suppress a decrease in light extraction efficiency.

  When the 1st optical member 3 is arrange | positioned between the laser element 2 and the fluorescence member 4, the light-incidence surface 3a and the light-projection surface 3b of the 1st optical member 3 are AR as shown in FIG.1 and FIG.2. It is preferable to have an (Anti-Reflective) coat 14. As a result, the transmittance of the laser light is improved, so that the efficiency of light incidence and emission at the first optical member 3 can be improved.

The first optical member 3 preferably has a flat upper surface so that the upper surface can be vacuum-sucked when mounted on the mounting surface of the substrate 1. Further, as shown in FIGS. 1 and 2, it is preferable to form a light shielding film 15 on the upper surface of the first optical member 3. Thereby, stray light can be reduced. That is, a part of the laser beam incident on the first optical member 3 is emitted from the upper surface of the first optical member 3 and may be transmitted to the outside through the lid 5, but the light shielding film 15 is provided. That can be suppressed. Specifically, the width of one side on the upper surface of the first optical member 3 can be set to 0.3 mm to 0.8 mm. The area of the upper surface of the first optical member 3 ^may be a 0.2mm ² ~1.6mm 2. Further, since the bottom surface of the first optical member 3 and the Au metallized surface of the mounting surface of the substrate 1 can be bonded with a bonding material such as Au nanoparticles or Au—Sn, the bottom surface of the first optical member 3 is Au It is preferably metallized with.

  The light incident surface 3a of the first optical member 3 is preferably substantially perpendicular to the optical axis of the incident laser light. By setting it as such a structure, the 1st optical member 3 can be manufactured easily.

  In the light emitting device 100, an error from the design value of the height of the laser element 2 and / or the second optical member 6 can be corrected by adjusting the mounting position of the first optical member 3. That is, first, the laser element 2 and the second optical member 6 are fixed to the base 1, and the first optical member 3 is placed on the base 1 in a temporarily placed state where the first optical member 3 is movable. The laser element 2 and the second optical member 6 are adjusted between straight lines connecting the fluorescent member 4. At this time, the laser element 2 is energized to cause laser oscillation, and while observing the laser beam, the position of the first optical member 3 is adjusted so that the laser beam is irradiated to a predetermined position, and the first optical member 3 is positioned and fixed. . Thereby, even if the height of the laser element 2 and / or the second optical member 6 is different from the design value, the laser light can be corrected to be incident on the first main surface of the fluorescent member 4. For this reason, the 1st optical member 3 can be arrange | positioned so that a laser beam may advance by the path | route with little fall of the utilization efficiency of a laser beam. The second optical member 6 may be omitted, but it is preferable to arrange the second optical member 6.

  As shown in FIG. 4, the laser element 2, the fluorescent member 4, and the first optical member 3 can be sequentially and linearly arranged on the mounting surface of the base 1 in a top view. In this case, the laser light passes above the fluorescent member 4 and enters the first optical member 3, and is reflected by the first optical member 3 and then enters the fluorescent member 4. However, as in the light emitting device 100 shown in FIG. 1 and the like, the laser element 2, the first optical member 3, and the fluorescent member 4 are arranged in order and linearly on the mounting surface of the base 1, thereby providing a laser. Light can be incident on the fluorescent member 4 at a relatively short distance from the laser element 2. Thereby, it becomes possible to make it small.

(Second optical member 6)
It is preferable to arrange the second optical member 6 between the laser element 2 and the first optical member 3. In the light emitting device 100, as shown in FIGS. 1 and 2, the second optical member 6 has a rectangular parallelepiped frame portion and a lens portion 6a, and the lens portion 6a has a shape protruding from the rectangular parallelepiped frame portion. The lens portion 6a is preferably one that condenses laser light or that makes parallel light. As a result, of the laser light emitted from the laser element 2, the light traveling toward the outside of the first optical member 3 is collected or converted into parallel light and incident on the first optical member 3. Can do. As a result, it is possible to suppress a decrease in utilization efficiency of laser light. Further, when the submount 7 is disposed under the laser element 2, the submount 7 can be thinned. That is, in order to make the light traveling downward from the first optical member 3 incident on the first optical member 3, it is not necessary to increase the light emitting point of the laser element 2 by increasing the thickness of the submount 7. Therefore, the submount 7 can be made thin. As a result, the heat generated by the laser element 2 can be effectively radiated to the base 1 and the light emitting device 100 can be made thin.

  As the lens portion 6a, it is preferable to use a cylindrical lens having a lens curvature in a direction in which the divergence angle of the laser beam is large. An example of such a cylindrical lens is shown in FIG. By using this, it is possible to collect the light that spreads in the vertical direction among the laser light. That is, the laser light emitted from the semiconductor laser element normally has a property of spreading in the vertical direction as compared with the horizontal direction, so that the laser light is efficiently condensed and incident on the first optical member 3. Can be made. Here, the horizontal direction is a direction parallel to the main surface of the laser element 2, and the vertical direction is a direction perpendicular thereto. Further, even if the laser beam traveling in the horizontal direction is not condensed, even if the path of the laser beam is deviated from the design value in the horizontal direction, the laser beam due to the positional deviation of the second optical member 6 will be described. Can be less affected. In the light emitting device 100, the cylindrical lens is arranged at the center of the rectangular parallelepiped frame. This facilitates not only making the optical axis of the cylindrical lens coincide with the optical axis of the laser light, but also making it easier to mount on the mounting surface of the substrate 1. Moreover, since the frame is a rectangular parallelepiped, the possibility that the cylindrical lens is inclined can be reduced.

  The curved surface of the lens portion 6a may be an aspherical surface or a spherical surface. The light incident surface of the lens unit 6a may be a flat surface. The curved surface of the lens portion 6a preferably has an AR coat.

  The second optical member 6 preferably has a flat upper surface so that the upper surface can be vacuum-sucked when mounted on the mounting surface of the substrate 1. In addition, since the lower surface of the second optical member 6 and the Au metallized surface of the mounting surface of the substrate 1 can be bonded with a bonding material such as Au nanoparticles or Au—Sn, the lower surface of the second optical member 6 is Au It is preferably metallized with.

[Fluorescent member 4]
The fluorescent member 4 is a member containing a phosphor. As the fluorescent member 4, for example, a phosphor obtained by sintering the phosphor itself may be used, or a phosphor obtained by adding a sintering aid to the phosphor material may be used.

  The fluorescent member 4 is preferably one that emits fluorescence so that white light can be obtained when combined with the laser element 2. Thereby, it can use as light sources, such as a vehicle headlamp and another illumination. For example, when blue light is emitted from the laser element 2, a phosphor that emits yellow light using the emitted light of the laser element 2 as excitation light can be used. Examples of the phosphor that emits yellow light include YAG phosphors. In addition, when light having a shorter wavelength than blue light (for example, ultraviolet light) is emitted from the laser element 2, phosphors that emit blue, green, and red colors can be used.

  When using a sintering aid, silicon oxide, aluminum oxide, or the like can be used as the sintering aid. Among these, it is particularly preferable to use aluminum oxide. This is because aluminum oxide has a high melting point and high resistance to heat and light.

  In the light emitting device 100, the fluorescent member 4 can be subjected to a light diffusion process. As the light diffusion treatment, for example, a rough surface treatment may be performed on the upper surface of the fluorescent member 4 or a scattering layer in which a filler is dispersed may be provided. Further, a filler may be dispersed inside the fluorescent member 4. Thereby, since the laser beam is scattered and then irradiated to the fluorescent member 4, the directivity of the reflected light can be reduced as compared with the case where the fluorescent member 4 is not subjected to the light diffusion process. As a result, the directivity of the reflected light and the wavelength converted light can be brought closer. Specifically, when the reflected light is, for example, blue light and the wavelength-converted light is, for example, yellow light, the color unevenness of white light extracted outside the light emitting device can be reduced by bringing these directivities close to each other. it can.

  The upper surface of the fluorescent member 4 is preferably closer to the mounting surface side of the substrate 1 than the light emitting point of the laser element 2. Thereby, it becomes easy to make a laser beam enter into the 1st main surface of the fluorescent member 4 from diagonally upward. The thickness of the fluorescent member 4 is preferably 0.05 mm to 0.5 mm, and more preferably 0.1 mm to 0.2 mm.

The shape of the fluorescent member 4 can be, for example, a rectangular parallelepiped, preferably having a width (W shown in FIG. 1) of 1 mm or less and a length (L shown in FIG. 1) of 1 mm or less. More preferably, the width is 0.5 mm or less and the length is 0.5 mm or less. If it is this range, the light emission area of the fluorescent member 4 can be made smaller and the brightness | luminance of the light-emitting device 100 can be made higher. In addition, as the light emitting area of the fluorescent member 4 is reduced, the light density of the light emitting surface when the fluorescent member 4 emits light is increased, and as the light density is increased, dust is easily collected on the light emitting surface of the fluorescent member 4. However, since the fluorescent member 4 is hermetically sealed in the light emitting device 100, the occurrence of dust collection on the light emitting surface of the fluorescent member 4 can be suppressed. Further, by setting the width of the fluorescent member 4 to 0.1 mm or more and the length to 0.1 mm or more, even if the position of the fluorescent member 4 is shifted on the mounting surface of the base body 1, the laser light is emitted from the fluorescent member 4. The possibility of detachment can be reduced. Thereby, it is possible to prevent the laser light from being directly taken out of the light emitting device 100 without passing through the fluorescent member 4. In the light emitting device 100, the shape of the fluorescent member 4 when viewed from above is substantially square, but may be a shape other than a square.
When the first optical member 3 is disposed between the laser element 2 and the fluorescent member 4, the laser element 2 and the fluorescent member 4 that are likely to be relatively hotter than other members can be separated from each other. The heat radiation efficiency of each of 2 and the fluorescent member 4 can be improved. The distance between the laser element 2 and the fluorescent member 4 is preferably 1 mm or more and 5 mm or less. By setting the thickness to 1 mm or more, heat interference between the laser element 2 and the fluorescent member 4 can be suppressed. By setting it to 5 mm or less, the laser light can be incident on the fluorescent member 4 at a relatively short distance from the laser element 2. As a result, it is possible not only to suppress a decrease in the utilization efficiency of the laser beam, but also to reduce the influence of the displacement of each member with respect to the laser beam. In addition, the light emitting device 100 can be downsized.

(Substrate 1)
As shown in FIG. 2, the base 1 can have a first recess 1 a that opens upward. In this case, since the laser element 2 and the like are mounted on the bottom surface of the first recess 1a, the bottom surface of the first recess 1a becomes the mounting surface of the base 1. As will be described later, the bottom surface of the first recess 1a can have a second recess 1b. In this case, the bottom surface of the second recess 1b is also used as the mounting surface of the substrate 1.

  The substrate 1 can be formed of ceramic and / or metal such as aluminum nitride or aluminum oxide. It is preferable to be composed mainly of aluminum nitride because the thermal conductivity and corrosion resistance can be improved. Further, when mainly composed of a ceramic having a laminated structure, as shown in FIG. 3, an internal wiring 10 that electrically connects a connection surface 9 and an external electrode 11 described later can be embedded in the substrate 1. By forming the internal wiring 10 on the base body 1, the inside and outside of the sealing space can be electrically connected, so that no lead terminal that penetrates the base body 1 is required, and airtight sealing is facilitated. The internal wiring 10 can be formed mainly from tungsten or molybdenum, for example.

  As shown in FIG. 2, a metal portion 13 to which the lid 5 is connected can be disposed on the upper surface of the base 1. The metal part 13 can have, for example, iron or Kovar as a main component, and Ni plating or Au plating may be applied to the surface. The metal part 13 is fixed to the upper surface of the base 1 with Ag brazing or the like. When the base body 1 is mainly composed of ceramic, the metal part 13 is disposed on the upper surface of the base body 1 so that the lid 5 can be fixed to the base body 1 by welding such as seam welding. Therefore, the hermetic sealing of the light emitting device 100 is facilitated.

  It is preferable that the bottom surface of the first concave portion 1a serving as the mounting surface of the substrate 1 is flat. Furthermore, the mounting surface of the base body 1 is preferably substantially parallel to the lower surface of the base body 1. By flattening, the heat dissipation efficiency of each member on the mounting surface of the substrate 1 can be made higher and more uniform by the heat sink that can be arranged on the lower surface of the substrate 1. The side surface of the first recess 1a of the substrate 1 can be a light shielding surface. In this case, it is preferable that all the side surfaces of the first recess 1a are light shielding surfaces. Thereby, even when the fluorescent member 4 is displaced and the laser light travels in the first recess 1a without hitting the fluorescent member 4, the laser light can be prevented from being emitted to the outside. In addition, generation of stray light can be suppressed. In addition, when the cover 5 comprises the side surface of the light-emitting device 100, it is preferable that the side surface of the cover 5 is also a light shielding surface. Thereby, the same effect is acquired.

  When the first optical member 3 is disposed between the laser element 2 and the fluorescent member 4, the base 1 is directly transmitted through the lid 5 in the first recess 1 a as shown in FIG. 2. It is preferable to have the light shielding part 12 that prevents the light from being emitted to the outside. The light-shielding portion 12 is preferably formed on the opposite side of the laser element 2 with the fluorescent member 4 in the top view, and is preferably formed above the upper surface of the fluorescent member 4. Furthermore, it is preferable that the light shielding portion 12 be a surface substantially parallel to the mounting surface of the substrate 1. Thereby, even when the fluorescent member 4 is displaced and the laser light travels in the first recess 1 a without hitting the fluorescent member 4, the laser light hits the light shielding portion 12 formed on the opposite side of the laser element 2. As a result, the possibility that the laser light is directly emitted to the outside of the light emitting device 100 can be reduced, so that the safety of the light emitting device 100 can be improved.

  As shown in FIGS. 1 and 3, the base body 1 preferably has a connection surface 9 electrically connected to an external electrode 11 described later in the first recess 1 a. The connection surface 9 is preferably a surface substantially parallel to the mounting surface of the base body 1 and is formed at a height above the mounting surface of the base body 1 and at the same level as the upper surface of the laser element 2. In the light emitting device 100, the laser element 2 and the submount 7 and the connection surface 9 are connected by four wires 8, respectively. The material of the wire 8 can be Au. When the substrate 1 is mainly made of ceramic, it is preferable to arrange a wiring layer such as a metal film on the connection surface 9. In this case, the wire 8 is connected to the wiring layer. The metal film can be configured to include a metal such as Au, Ag, Al, Ti, Pt, Ni, and Pd.

  As shown in FIG. 1, the base 1 can have an external electrode 11 on the upper side for electrical connection with the outside. The external electrode 11 is electrically connected to the connection surface 9 by the internal wiring 10. In the light emitting device 100, the external electrode 11 and the connection surface 9 are arranged close to each other across the inner edge of the first recess 1 a of the base 1 in a top view.

  For example, a metal film can be used as the external electrode 11. The metal film can be configured to include, for example, Au, Ag, Al, Ti, Pt, Ni, and Pd. The metal film as the external electrode 11 can be made of the same material as the metal film disposed on the connection surface.

(Cover 5)
As shown in FIG. 2, the lid 5 is connected to the upper surface of the base 1 so as to close the opening of the first recess 1a, and the laser element 2, the fluorescent member 4 and the first optical member 3 are placed in the first recess 1a. Is sealed. The lid 5 is preferably joined to the base 1 so as to hermetically seal the base 1. That is, for example, if the laser element 2 is a GaN-based semiconductor laser element, the light emission surface 3b of the laser element 2 and the vicinity thereof have a particularly high light density and easily collect organic matter and the like. Can be effectively prevented. In addition, the influence of external moisture on the fluorescent member 4 can be reduced. Further, by airtightly sealing each member in the first recess 1a that is one space, for example, the light emitting device 100 can be reduced in size as compared with the case where only the laser element 2 is hermetically sealed.

  The lid 5 has a translucent member 5 a that transmits light from the fluorescent member 4. As the translucent member 5a, it is preferable to select a member having a linear expansion coefficient similar to that of a holding member 5b described later, since the airtightness of the base 1 can be improved. Specifically, glass or the like can be used as the translucent member 5a. In the light emitting device 100, borosilicate glass is used as the translucent member 5a. Moreover, it is preferable that the translucent member 5a has AR coating on both surfaces. Thereby, the transmittance | permeability of a laser beam can be improved and the fall of light extraction efficiency can be suppressed. In the light emitting device 100, the translucent member 5a does not contain a phosphor.

  The distance between the lower surface of the lid 5 and the upper surface of the fluorescent member 4 is preferably 5 mm or less. Thereby, the light extraction efficiency from the light emitting device 100 can be improved. That is, since the light from the fluorescent member 4 spreads away from the fluorescent member 4, the light from the fluorescent member 4 can strike other than the translucent member 5a by bringing the lower surface of the lid 5 close to the upper surface of the fluorescent member 4. The light extraction efficiency can be improved.

The lid 5 preferably has a holding member 5b having a through hole. In the light emitting device 100, as shown in FIG. 1, the through hole is circular, but the shape is not particularly limited. As shown in FIGS. 1 and 2, the translucent member 5a is fixed so as to close the through hole of the holding member 5b. In addition, since the portion other than the through hole of the holding member 5b has light shielding properties, it is possible to reduce the possibility that the laser light is emitted directly to the outside of the light emitting device 100 without hitting the fluorescent member 4. The safety of the light emitting device 100 can be improved. In other words, when viewed from above, the entire area of the mounting surface of the substrate 1 other than the area overlapping with the through hole is covered with the light-shielding holding member 5b, so that the fluorescent member 4 is displaced, and the laser light is applied to the fluorescent member 4. Even when the light travels in the first recess 1a without hitting it, the laser light can be prevented from being directly emitted to the outside. In addition, generation of stray light can be suppressed. The holding member 5b can be made of a metal such as Kovar, and the surface thereof may be plated with Ni or Au. The holding member 5b and the translucent member 5a can be joined with, for example, low-melting glass.
As shown in FIG. 2, it is preferable that the through hole of the holding member 5 b is arranged at a position where the laser beam regularly reflected by the first main surface of the fluorescent member 4 is not irradiated. That is, the light from the laser element 2 is refracted by the first optical member 3 and enters the fluorescent member 4 at a predetermined angle, but the laser light that is regularly reflected by the first main surface of the fluorescent member 4 out of the incident light. It is preferable that a through-hole is arrange | positioned in the position which is not irradiated. Thereby, even if it is a case where the position of the fluorescent member 4 has shifted | deviated, possibility that a laser beam will be radiate | emitted directly outside can be reduced.

  When the lid 5 has the translucent member 5a and the holding member 5b, the base body 1 and the holding member 5b can be connected by welding such as seam welding. Since the holding member 5b and the base body 1 can be more firmly fixed by welding, the light-emitting device 100 in which the lid 5 is difficult to be detached from the base body 1 even when the light-emitting device 100 is subjected to an impact such as vibration. Can do.

  It is preferable that the holding member 5 b has a recess and is connected to the upper surface of the base 1 so that a part of the recess of the holding member 5 b is located in the first recess 1 a of the base 1. In this case, the through hole of the holding member 5b is provided on the bottom surface of the concave portion of the holding member 5b, and the translucent member 5a is disposed in the concave portion of the holding member 5b. Thereby, since the member arrange | positioned outside the light-emitting device 100 becomes difficult to contact the translucent member 5a, the possibility of damage to the translucent member 5a can be reduced. Moreover, since the fluorescent member 4 and the translucent member 5a can be brought close to each other, the light from the fluorescent member 4 that transmits the translucent member 5a can be increased, and the light extraction efficiency from the fluorescent member 4 can be increased. .

  In the light emitting device 100, the holding member 5 b has a shape that extends toward the center of the substrate 1, then bends and extends downward, and further bends and extends toward the center of the substrate 1. A recess 5b is formed. As a result, the stress caused by the difference in thermal expansion coefficient between the base 1 and the holding member 5b can be reduced in the region extending below the holding member 5b, so that the plastic deformation of the holding member 5b and the breakage of the translucent member 5a are prevented. Can be suppressed.

  The light emitting device 100 has a substantially rectangular shape when viewed from above. The length of one side of the light emitting device 100 is preferably 5 mm or more, and more preferably 10 mm or more, for heat dissipation. On the other hand, the length of one side of the light emitting device 100 is preferably 25 mm or less and more preferably 20 mm or less in order to reduce the size of the light emitting device 100. In addition, when the base 1 has the first concave portion 1a that is rectangular when viewed from the top surface, the length of the upper end of the concave portion, that is, the length of one side of the inner edge of the top surface of the base 1 is set to place a member such as the laser element 2 or the like. It is preferably 1 mm or more, and more preferably 2 mm or more. On the other hand, the length of one side of the inner edge of the upper surface of the substrate 1 is preferably 15 mm or less, and more preferably 10 mm or less, in order to suppress an increase in the size of the light emitting device 100. The thickness of the light emitting device 100 is preferably 6 mm or less. Here, the thickness of the light emitting device 100 refers to the length from the lower surface of the substrate 1 to the upper surface of the lid 5.

[Embodiment 2]
The light emitting device 200 according to the second embodiment is different from the first embodiment in that the fluorescent member 4 is disposed in the second concave portion 1b formed in the first concave portion 1a, and the first optical member 3 is located above the fluorescent member 4. It differs in that it is arranged. The rest is the same as in the first embodiment.

  In the light emitting device 200 according to the second embodiment, as shown in FIG. 6, the fluorescent member 4 is disposed in the second concave portion 1 b formed in the first concave portion 1 a of the base 1, and the first optical member 3 is fluorescent. It is arranged above the member 4. A second optical member 6 is disposed between the first optical member 3 and the laser element 2. Here, the first optical member 3 has a bottom surface facing the mounting surface of the substrate 1 and an inclined surface 3 c, and the bottom surface and the inclined surface 3 c of the first optical member 3 are incident on the first optical member 3. When the laser beam is totally reflected by the inclined surface 3c in the direction toward the first main surface of the fluorescent member 4, and the light from the fluorescent member 4 is incident on the bottom surface of the first optical member 3, the light is incident on the inclined surface 3c. The angle is refracted by. As a result, the laser light is condensed on the second optical member 6 and incident on the first optical member 3, and the laser light is once totally reflected by the inclined surface 3 c of the first optical member 3, so that the first of the fluorescent member 4. The main surface is irradiated from the bottom surface of the first optical member 3 to excite the fluorescent member 4. The excited fluorescent member 4 emits wavelength-converted light mainly upward, and enters the bottom surface of the first optical member 3 together with the reflected light reflected by the fluorescent member 4 without exciting the fluorescent member 4. After being refracted by the inclined surface 3 c of the optical member 3, it is taken out of the light emitting device 200. In the light emitting device 200, the bottom surface of the first recess 1a and the bottom surface of the second recess 1b are both flat and parallel to each other.

  According to this configuration, since the laser light can be incident on the fluorescent member 4 at an incident angle near vertical, more of the reflected light (for example, blue light) can travel upward, and the light from the light emitting device 200 can be extracted. Efficiency can be improved. In addition, since the ratio at which the laser light is reflected from the upper surface of the fluorescent member 4 can be reduced as compared with the case where the laser light is incident on the fluorescent member 4 at an incident angle closer to the horizontal, the fluorescent member 4 is reduced. The excitation efficiency of can be improved. Further, by adjusting the angle formed between the bottom surface of the first optical member 3 and the inclined surface 3c of the first optical member 3, the angle at which light is emitted to the top surface can be adjusted according to the design of the light emitting device 200. Therefore, the light extraction efficiency can be improved. Specifically, the angle formed between the bottom surface of the first optical member 3 and the inclined surface 3c is preferably set to 30 degrees to 40 degrees. Further, in the second embodiment, similarly to the first embodiment, the laser light can be incident on the fluorescent member 4 at a short distance from the laser element 2, so that a decrease in the utilization efficiency of the laser light can be reduced. Further, it is possible to reduce the influence of the displacement of each member with respect to the laser light. Furthermore, the light emitting device 200 can be reduced in size.

  Since the fluorescent member 4 is disposed in the second concave portion 1b formed in the first concave portion 1a and the first optical member 3 is disposed thereon, the fluorescent member 4 is fixed to the mounting surface of the base body 1. The possibility that the fluorescent member 4 will shift later can be reduced. Thereby, since possibility that a laser beam will be radiate | emitted outside the light-emitting device 200, without hitting the fluorescent member 4, the safety | security of the light-emitting device 200 can be improved. Further, when the fluorescent member 4 is bonded to the bottom surface and the side surface of the second recess 1b, the fluorescent member bonded to the base body 1 is compared with the case where the fluorescent member 4 is bonded only to the mounting surface of the base body 1. The surface area of 4 can be increased. Thereby, the heat dissipation efficiency from the fluorescent member 4 to the base | substrate 1 can be improved. In addition, joining with the mounting surface etc. of the base | substrate 1 with the fluorescent member 4 includes the case where it joins via an adhesive agent.

DESCRIPTION OF SYMBOLS 100 Light-emitting device 200 Light-emitting device 1 Base | substrate 1a 1st recessed part 1b 2nd recessed part 2 Laser element 3 1st optical member 3a Light incident surface 3b Light-emitting surface 3c Inclined surface 4 Fluorescent member 5 Cover body 5a Translucent member 5b Holding member 6 Second optical member 6a Lens portion 7 Submount 8 Wire 9 Connection surface 10 Internal wiring 11 External electrode 12 Light shielding portion 13 Metal portion 14 AR coating 15 Light shielding film W Fluorescent member width L Fluorescent member length

Claims (8)

A substrate;
A laser element disposed on the mounting surface of the substrate;
A fluorescent member having a first main surface and a second main surface opposite to each other, the second main surface side being fixed to the mounting surface of the substrate;
A first optical member that changes a traveling direction of laser light emitted from the laser element to a direction toward the first main surface of the fluorescent member;
A lid that transmits light from the fluorescent member and is connected to the base and seals the laser element, the fluorescent member, and the first optical member;
A light emitting device comprising:   The light emitting device according to claim 1, wherein a mounting surface of the base is flat.   3. The light emitting device according to claim 1, wherein the laser element, the first optical member, and the fluorescent member are sequentially arranged on a mounting surface of the base body.   4. The second optical member according to any one of claims 1 to 3, wherein a second optical member that condenses laser light emitted from the laser element or converts it into parallel light is disposed between the laser element and the first optical member. The light-emitting device described in 1.   The light emitting device according to any one of claims 1 to 4, wherein the first optical member is a prism. The prism has a bottom surface facing the mounting surface of the base and a light emitting surface for emitting the laser light,
The light emitting device according to claim 5, wherein a bottom surface of the prism and a light emitting surface form an acute angle.   The light-emitting device according to claim 5, wherein the prism has an AR coat on a light incident surface and a light emitting surface on which the laser light is incident.   The said base | substrate has the light-shielding part which shielded the said laser beam and was provided in the other side of the said laser element on both sides of the said fluorescent member and spaced apart from the mounting surface of the said base | substrate. The light emitting device according to any one of claims 4 to 7.

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