Light-emitting device

Abstract

To realize a suitable wiring pattern for electrically connecting multiple light-emitting elements, in a light-emitting device where the multiple light-emitting elements are arranged on one face.SOLUTION: A light-emitting device has multiple semiconductor laser elements placed on the bottom face, a frame part surrounding the multiple semiconductor laser elements placed on the bottom face, a light reflection member for reflecting laser light, progressing from the multiple semiconductor laser elements placed on the bottom face toward the first inside surface of the frame part, a step part formed along the second inside surface of the frame part on the inside of a frame formed by the top face of the frame part, multiple metal films provided on the top face of the step part, multiple wires for electrically connecting the multiple semiconductor laser elements, and a protection element placed on the top face of the step part on the farther light progressing side than a plane including the light emission end face of the semiconductor laser element.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a light emitting device. [Background technology]

[0002] Patent Document 1 discloses a light emitting device package having a bottom where a light emitting element is disposed and a step provided on the outer periphery of the light emitting element. It also discloses providing a wire bonding area on the upper surface of the step, and bonding the wire to this area and the light emitting element for electrical connection. It also discloses providing a Zener diode on the upper surface of the step. This light emitting device package has one cavity for each light emitting element, so that the size of the bonding area increases in proportion to the number of light emitting elements. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2011-254080 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 does not assume a configuration in which multiple light-emitting elements are provided in one cavity. In a light-emitting device in which multiple light-emitting elements are arranged on one surface, it is still necessary to devise a wiring pattern. [Means for solving the problem]

[0005] A light emitting device according to the present invention includes a frame portion having a base having a bottom surface, two first inner side surfaces facing each other in a first direction across the bottom surface, two second inner side surfaces facing each other in a second direction across the bottom surface, a first step portion provided along one of the two second inner side surfaces and a second step portion provided along the other of the two second inner side surfaces, a first semiconductor laser element and a second semiconductor laser element, the frame portion including a plurality of semiconductor laser elements disposed on the bottom surface and emitting laser light traveling toward the first inner side surface, and one or more light reflectors disposed on the bottom surface and reflecting the laser light emitted from the plurality of semiconductor laser elements disposed on the bottom surface. and a plurality of wires joined to an upper surface of the first step portion or an upper surface of the second step portion to electrically connect the plurality of semiconductor laser elements to the frame portion, wherein the first semiconductor laser elements are arranged closer to the first step portion than the second semiconductor laser elements, and the second semiconductor laser elements are arranged closer to the second step portion than the first semiconductor laser elements, and all of the wires electrically connecting the first semiconductor laser elements to the frame portion are not joined to the upper surface of the second step portion, and all of the wires electrically connecting the second semiconductor laser elements to the frame portion are not joined to the upper surface of the first step portion. Effect of the Invention

[0006] According to the present invention, the light reflected by the light reflecting surface can be emitted from the light emitting device without being obstructed by the wire. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view of the light emitting device according to the first embodiment. [Diagram 2] FIG. 2 is a top view of the light emitting device according to the first embodiment. [Diagram 3] FIG. 3 is a perspective view for explaining the internal structure of the light emitting device according to the first embodiment. [Figure 4] FIG. 4 is a top view for explaining the internal structure of the light emitting device according to the first embodiment. [Diagram 5]FIG. 5 is a top view of the base of the light emitting device according to the first embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the light emitting device taken along line VI-VI in FIG. [Figure 7] FIG. 7 is a top view of a light emitting device in which a protective element is connected by a wire. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In this specification and claims, polygons such as triangles and quadrangles are referred to as polygons, including shapes in which the corners of the polygons have been processed, such as by rounding, chamfering, removing the corners, or rounding off the edges. In addition, shapes in which processing has been applied to the middle parts of the sides, not just the corners (edges), are also referred to as polygons. In other words, shapes that have been processed based on a polygon are included in the interpretation of "polygon" described in this specification and claims.

[0009] This is not limited to polygons, but also applies to words expressing specific shapes such as trapezoids, circles, and irregular shapes. The same is true when dealing with each side that forms the shape. In other words, even if the corners or middle part of a side have been processed, the interpretation of "side" includes the processed part. Note that when distinguishing "polygons" or "sides" that have not been intentionally processed from processed shapes, the word "strict" is added, for example, "strict quadrangle."

[0010] Hereinafter, a description will be given of an embodiment of the present invention with reference to the drawings. However, the embodiment shown is an embodiment of the technical idea of ​​the present invention, but does not limit the present invention. In the following description, the same names and symbols indicate the same or similar components, and duplicated descriptions may be omitted as appropriate. The sizes and positional relationships of the components shown in each drawing may be exaggerated to clarify the description.

[0011] First Embodiment FIG. 1 is a perspective view of a light emitting device 1 according to a first embodiment. FIG. 2 is a top view of the light emitting device 1 shown in FIG. 1. FIG. 3 is a perspective view for explaining the internal structure of the light emitting device 1, and is a perspective view in which a cover member 80 is omitted. FIG. 4 is a top view of the light emitting device 1 shown in FIG. 3. FIG. 5 is a top view showing only a base 10 of the light emitting device 1. FIG. 6 is a cross-sectional view of the light emitting device 1 taken along line VI-VI in FIG. 2.

[0012] The light emitting device 1 has a base 10, three semiconductor laser elements 30, a submount 40, a light reflecting member 50, six protective elements 60, nine wires 70, and a lid member 80 as components.

[0013] The base 10 has a rectangular outer shape when viewed from above, with a concave shape recessed on the inside. This concave shape forms a recess that is recessed from the top surface toward the bottom surface. The base 10 has a top surface 11, a bottom surface 12, a bottom surface 13, an inner surface 14, and an outer surface 17. The base 10 also forms a step portion 20 in the recess, which is composed of a top surface and a side surface. The top surface of the step portion 20 is referred to as a step portion top surface 21, and the side surface of the step portion 20 is referred to as a step portion side surface 22.

[0014] Top surface 11 intersects with outer surface 17 and inner surface 14, and bottom surface 13 intersects with outer surface 17. Bottom surface 12 is higher than bottom surface 13 and lower than top surface 11. In the region where step portion 20 is formed, step portion side surface 22 intersects with bottom surface 12, and step portion top surface 21 intersects with inner surface 14. In the region where step portion 20 is not formed, bottom surface 12 intersects with inner surface 14.

[0015] In top view, the recess forms a recessed space inside the frame formed by the top surface 11. This frame has a rectangular outer shape. A step portion 20 is formed inside this rectangular frame. The step portion 20 is provided along the inner surface 14 on each of the inner surfaces 14 relating to two opposing sides of the rectangular outer shape. The step portion 20 is provided over the entire length of the inner surface 14 relating to the two sides, where the inner surface 14 relating to the two sides intersects with the inner surface 14 relating to the two sides. The step portion 20 is not provided on the inner surface 14 relating to the remaining two opposing sides, except at the intersection.

[0016] Here, the intersection is an edge portion where a surface intersects with another surface. The inner surface 14 on the side where the step portion 20 is not provided, excluding the intersection, is referred to as the first inner surface 15, and the inner surface 14 on the side where the step portion 20 is provided is referred to as the second inner surface 16. Similarly, the outer surface 17 on the first inner surface side is referred to as the first outer surface 18, and the outer surface 17 on the second inner surface side is referred to as the second outer surface 19. When distinguishing between the two step portions 20 provided along each inner surface, they are referred to as the first step portion and the second step portion.

[0017] The width of the top surface 11 from the outer surface 17 to the inner surface 14 is the same except for the intersection. The same width here includes a difference of 10%. Also, the distance from the outer surface 17 to the bottom surface 12 in top view is longer from the second outer surface 19 than from the first outer surface 18 by the amount of the step portion 20. In this structure, the base 10 is more resistant to warping that occurs during the manufacturing process in the direction related to the second outer surface 19 than in the direction related to the first outer surface 18.

[0018] In the base 10, the sides relating to the second inner side surface 16 are longer than the sides relating to the first inner side surface 15. Also, the sides relating to the second outer side surface 19 are longer than the sides relating to the first outer side surface 18. In consideration of deformation of the base 10 due to warping, it is preferable that the length of the sides relating to the first inner side surface 15 or the first outer side surface 18 is shorter than the length of the sides relating to the second inner side surface 16 or the second outer side surface 19, which are more resistant to warping. The relationship between the lengths of the sides may be the same or reversed.

[0019] The base 10 can be formed mainly from ceramics. Examples of ceramics used for the base 10 include aluminum nitride, silicon nitride, aluminum oxide, and silicon carbide.

[0020] Further, a plurality of metal films 25 are provided on the lower surface 13 of the base 10 and the stepped portion upper surface 21. The metal film 25 provided on the lower surface 13 of the base 10 and the metal film 25 provided on the stepped portion upper surface 21 are connected via a metal passing through the inside of the base 10, and can be electrically connected.

[0021] A plurality of metal films 25 are provided on each of the step upper surfaces 21 of the first step portion 23 and the second step portion 24. The plurality of metal films 25 provided on each are arranged symmetrically so as to face each other. Note that the first step portion 23 and the second step portion 24 do not necessarily have to have the metal films 25 provided in a symmetrical arrangement.

[0022] Moreover, on the step portion upper surface 21 of the step portion 20 associated with one second inner side surface 16, the multiple metal films 25 are provided in order from one end of the side associated with the second inner side surface 16 to the other end. That is, a straight line parallel to this side intersects with all the metal films 25 provided on the step portion upper surface 21 associated with one second inner side surface 16. Moreover, a straight line perpendicular to this side intersects with one of all the metal films 25 provided on the step portion upper surface 21 associated with one second inner side surface 16.

[0023] The base 10 may be formed by joining the frame and the bottom, with the bottom including the bottom surface 12 and the frame including the inner side surface 14 and the step portion 20 forming a frame surrounding the bottom being made of different main materials. In this case, for example, the main material of the frame may be ceramic, and the main material of the bottom may be metal having a higher thermal conductivity than ceramic.

[0024] The semiconductor laser element 30 has a rectangular outer shape when viewed from above. A side surface intersecting one of the two short sides of the rectangle serves as an emission end surface for light emitted from the semiconductor laser element 30. The upper and lower surfaces of the semiconductor laser element 30 have areas larger than that of the emission end surface.

[0025] Each of the three semiconductor laser elements 30 is a multi-emitter having two emitters. One electrode surface common to the two emitters is provided on the lower surface of the semiconductor laser element 30, and two electrode surfaces corresponding one-to-one to the two emitters are provided on the upper surface.

[0026] The laser light emitted from each emitter has a spreading property and forms an elliptical far-field pattern (FFP) on a plane parallel to the light output facet. FFP is the shape and light intensity distribution of the output light at a position away from the output facet. The light intensity distribution is 1 / e 2 The light having an intensity equal to or greater than this will be referred to as the main portion of the light.

[0027] The three semiconductor laser elements 30 are composed of a semiconductor laser element that emits blue light, a semiconductor laser element that emits green light, and a semiconductor laser element that emits red light. If necessary, the three semiconductor laser elements are distinguished as a first semiconductor laser element, a second semiconductor laser element, and a third semiconductor laser element.

[0028] For example, in one embodiment shown in FIG. 3, the three semiconductor laser elements 30 are composed of a first semiconductor laser element 31 that emits blue light, a second semiconductor laser element 32 that emits green light, and a third semiconductor laser element 33 that emits red light.

[0029] Here, blue light refers to light whose emission peak wavelength is in the range of 420nm to 494nm, green light refers to light whose emission peak wavelength is in the range of 495nm to 570nm, and red light refers to light whose emission peak wavelength is in the range of 605nm to 750nm.

[0030] The first semiconductor laser element 31 and the second semiconductor laser element 32 have rectangular long sides with the same length in the top view. Here, the same length includes a difference of 20%. The third semiconductor laser element 33 has a rectangular long side with a longer length in the top view than either the first semiconductor laser element 31 or the second semiconductor laser element 32. Specifically, the third semiconductor laser element 33 is more than 20% longer than the longer of the first semiconductor laser element 31 or the second semiconductor laser element 32.

[0031] The semiconductor laser element 30 may be a single emitter. Also, single-emitter and multi-emitter semiconductor laser elements 30 may be mixed. The number of semiconductor laser elements is more than one, but is not limited to three. The light emitted by the semiconductor laser element 30 is not limited to those listed here. Also, a plurality of semiconductor laser elements 30 of the same color may be arranged.

[0032] Furthermore, the "first" to "third" used to distinguish the three semiconductor laser elements 30 may refer to different semiconductor laser elements as necessary. For example, the semiconductor laser element emitting red light may be expressed as the first semiconductor laser element, the semiconductor laser element emitting blue light as the second semiconductor laser element, and the semiconductor laser element emitting green light as the third semiconductor laser element.

[0033] Also, for example, the semiconductor laser element with the larger long side of the rectangle in the top view outline may be expressed as the first semiconductor laser element, and the semiconductor laser element with the smaller long side may be expressed as the second semiconductor laser element. The letters "first" and "second" are symbols for distinction and may be used appropriately depending on the manner of distinction.

[0034] The submount 40 is configured in a rectangular parallelepiped shape. The side of the submount 40 in the height direction is the smallest. The submount 40 is formed using, for example, silicon nitride, aluminum nitride, or silicon carbide. However, the submount 40 is not limited to these materials, and other materials may also be used. A metal film 25 is provided on the upper surface of the submount 40.

[0035] The light reflecting member 50 has a light reflecting surface that is inclined with respect to the lower surface. The light reflecting surface is flat and designed to form an angle of 45 degrees with respect to the lower surface. However, this angle does not have to be limited to 45 degrees. The light reflecting surface may also be a curved surface.

[0036] The light reflecting member 50 can be mainly made of glass or metal. The main material is preferably a heat-resistant material, for example, glass such as quartz or BK7 (borosilicate glass), metal such as Al, or Si. Metals such as Ag and Al, and dielectric multilayer films such as Ta2O5 / SiO2, TiO2 / SiO2, and Nb2O5 / SiO2 can be used for the light reflecting surface.

[0037] The light reflecting surface can have a light reflectance of 99% or more for the peak wavelength of the laser light to be reflected. The light reflectance can be 100% or less or less. The protective element 60 is for preventing an excessive current from flowing through a specific element (e.g., the semiconductor laser element 30) and destroying it. An example of the protective element 60 is a Zener diode. Also, a Zener diode made of Si can be used. The wire 70 is, for example, a metal wiring.

[0038] The lid member 80 is configured in a rectangular parallelepiped shape. The side of the lid member 80 in the height direction is the smallest. The lid member 80 is formed using a light-transmitting material as the main material. For example, sapphire can be used as the main material. Sapphire has a relatively high refractive index and is relatively strong. A metal film for bonding is provided on the outer peripheral region of the lower surface of the lid member 80.

[0039] The cover member 80 may have a non-transparent region on a part of the upper surface or the lower surface. For example, a region having high reflectivity or light blocking properties may be provided in a part of the cover member 80. The shape is not limited to a rectangular parallelepiped. The cover member 80 may be mainly made of glass or the like.

[0040] Next, a light emitting device 11 manufactured using these components will be described. First, the protective element 60 is placed on the step upper surface 21. For example, when a Si protective element is to be placed, a ceramic base 10 is more preferable for bonding than a base made of resin. This is because the difference in linear expansion coefficient between the protective element and ceramic is smaller.

[0041] Moreover, one protective element 60 is provided corresponding to one emitter. That is, two protective elements 60 are provided for one semiconductor laser element 30 having two emitters. In this manner, in the light emitting device 1, a greater number of protective elements 60 than the semiconductor laser elements 30 are arranged inside the frame. Providing at least one or more protective elements on the step portion upper surface 21 contributes to miniaturization of the light emitting device 1.

[0042] The two protection elements 60 corresponding to one semiconductor laser element 30 are each connected to two metal films 25 provided on the upper surface 21 of the step portion, thereby connecting one to the cathode electrode and the other to the anode electrode, thereby establishing an electrical connection.

[0043] The protective element 60 is disposed so as to straddle the metal film 25 of the cathode electrode to which it is connected and the anode electrode and metal film 25. In this manner, the protective element 60 can be electrically connected without using the wire 70. Therefore, the protective element 60 is electrically connected to two metal films 25 disposed adjacent to each other.

[0044] Note that, instead of arranging the protective element 60 across the two metal films 25, a separate wire 71 may be used for connection. Fig. 7 shows a light emitting device 1A as an example of a configuration in which a protective element 60 is arranged on one metal film 25 and a wire 71 is bonded to the protective element 60 and the other metal film 25. In this case, after the protective element 60 is arranged, the wire 71 is bonded to the protective element 60 and the metal film 25. Note that when distinguishing from the wire 70 for electrically connecting the semiconductor laser element 30 described later, the wire 71 is expressed as a first wire and a second wire.

[0045] The protective element 60 is provided on the step portion upper surface 21 of the step portion 20 provided over the entire length of the side related to the second inner side surface 16 of the recess, close to the end of this side in top view. Here, two protective elements 60 are arranged close to one end of the side in each of the first step portion 23 and the second step portion 24. Also, one protective element 60 is arranged close to the other end of the side. Although details will be described later, such an arrangement, in conjunction with the arrangement of the semiconductor laser element 30 and the light reflecting member 50, facilitates wire connection of the semiconductor laser element 30.

[0046] Next, the three semiconductor laser elements 30 are arranged side by side on the submount 40. An electrode surface provided on the lower surface of each semiconductor laser element 30 is bonded to a metal film 25 provided on the upper surface of the submount 40. The second semiconductor laser element 32 is arranged next to the first semiconductor laser element 31, and the third semiconductor laser element 33 is arranged next to the second semiconductor laser element 32.

[0047] That is, the first semiconductor laser element 31 and the second semiconductor laser element 32 are adjacent to each other, the second semiconductor laser element 32 and the third semiconductor laser element 33 are adjacent to each other, and the second semiconductor laser element 32 is sandwiched between the first semiconductor laser element 31 and the third semiconductor laser element 33. Note that the third semiconductor laser element 33 may be disposed adjacent to the first semiconductor laser element 31 instead of adjacent to the second semiconductor laser element 32.

[0048] The three semiconductor laser elements 30 are aligned and arranged so that their emission end faces face one side surface of the submount 40. The emission end face is arranged on the same plane as the side surface of the submount 40, or is arranged to protrude outward beyond the side surface of the submount 40. This side surface of the submount 40 is referred to as the side surface on the emission end face side. By arranging them in this manner, it is possible to prevent the emitted light from being directly irradiated onto the upper surface of the submount 40.

[0049] The submount 40 can also play a role in releasing heat generated from the semiconductor laser element 30. Specifically, the submount 40 may be made of a material with better thermal conductivity than the semiconductor laser element 30. Therefore, when the submount 40 plays this role, it can be regarded as a heat dissipation member. By bonding the lower surface, which has a larger area, of the semiconductor laser element to the submount 40 instead of the emission end surface, the heat dissipation can be improved.

[0050] In addition, the submount 40 raises the light emission position of the semiconductor laser element 30. In other words, the submount 40 adjusts the position of the light irradiated on the light reflecting surface by setting the light emission position higher, and therefore may be regarded as an adjustment member. Note that a submount 40 may be provided separately for each semiconductor laser element 30.

[0051] Next, the submount 40 on which the semiconductor laser element 30 is disposed is disposed on the bottom surface 12 of the base 10. The submount 40 is disposed on the bottom surface 12 inside the frame formed by the frame portion of the base 10. The submount 40 is further disposed on the bottom surface 12 inside the step portion 20 of the base 10.

[0052] Moreover, the submount 40 is disposed so that the emission end face of the semiconductor laser element 30 faces the first inner side face 15 of the base 10. The side face opposite the emission end face of the semiconductor laser element is disposed so as to face the first inner side face 15 opposite to the first inner side face 15 with which the emission end face faces. The two side faces intersecting with the emission end face of the semiconductor laser element are disposed so as to face the second inner side face 16 of the base 10 or side faces intersecting with the emission end face of the semiconductor laser element 30 disposed adjacently.

[0053] Therefore, the emitted light from the semiconductor laser element 30 travels in the direction of the first inner surface 15. In particular, in any of the semiconductor laser elements, when light traveling in a direction perpendicular to the emitting end face (hereinafter referred to as light traveling along the optical axis) travels straight, the light hits the first inner surface 15. The emitting end face and the first inner surface 15 on which the light traveling along the optical axis hits are parallel. The second inner surface 16 has an area parallel to both side surfaces that intersect with the emitting end face. Here, "parallel" includes a difference of plus or minus 5 degrees. It is not necessary for the light to be parallel.

[0054] Next, the light reflecting member 50 is placed on the bottom surface 12 of the base 10. The light reflecting member 50 reflects the light emitted from all of the three semiconductor laser elements 30 placed on the bottom surface 12. Therefore, the light reflecting surface is placed so as to face the emission end surface side. When viewed from above, the upper and lower ends of the inclination of the light reflecting surface are parallel to the side surface of the submount 40 on the emission end surface side. The light traveling along the optical axis is reflected by the light reflecting surface and travels vertically upward from the bottom surface 12. Here, vertical includes a difference of plus or minus 5 degrees.

[0055] Incidentally, instead of using one light reflecting member 50 to reflect the light from all of the semiconductor laser elements 30, a light reflecting member 50 may be disposed individually for each semiconductor laser element 30, and each light reflecting member 50 may reflect the light from the corresponding semiconductor laser element.

[0056] In a state where the light reflecting member 50 and the submount 40 are arranged so as to reflect the light emitted from the semiconductor laser element 30, the smallest rectangle that encompasses the light reflecting member 50 and the submount 40 has a width in a direction perpendicular to the direction of the light emitting end face that is longer than the width in this direction. Therefore, the light emitting device 1 is arranged so as to be compact with respect to the base 10 whose side relating to the second inner surface 16 is longer than the side relating to the first inner surface 15.

[0057] Here, the positional relationship between the semiconductor laser element 30, the submount 40, and the light reflecting member 50 and the protective element 60 will be described. In comparing the positional relationship, a side in the direction in which light from the semiconductor laser element 30 travels is referred to as being on the light travelling side, and a side in the opposite direction is referred to as being on the element side. For example, when comparing opposing first inner side surfaces 15, the first inner side surface 15 at the end of the direction in which light emitted from the semiconductor laser element travels is the first inner side surface 15 on the light travelling side, and the first inner side surface 15 on the opposite side is the first inner side surface 15 on the element side.

[0058] In addition, the three protective elements 60 arranged on the step portion upper surface 21 of the step portion 20 provided along one second inner surface 16 will be distinguished and referred to as the first protective element 61, the second protective element 62, and the third protective element 63, in that order from the light traveling side toward the element side.

[0059] The submount 40 is disposed in a position in which the emission end face of the semiconductor laser element 30 is closer to the first inner surface 15 on the light traveling side than the center of the opposing first inner surface 15 in the direction parallel to the second inner surface 16. In other words, the distance from the emission end face of the semiconductor laser element 30 to the first inner surface 15 on the light traveling side is smaller than the distance from the center of the opposing first inner surface 15 to the first inner surface 15 on the light traveling side. Therefore, the light emission end face of the semiconductor laser element 30 is provided on the light traveling side rather than the center in the space within the recess.

[0060] Moreover, in the submount 40, in relation to the direction parallel to the second inner lateral surface 16, the side surface opposite to the emission end surface of the semiconductor laser element 30 is disposed at a position closer to the first inner lateral surface 15 on the element side than to the center of the opposing first inner lateral surface 15. Moreover, all of the first semiconductor laser element 31, the second semiconductor laser element 32, and the third semiconductor laser element 33 satisfy this positional relationship.

[0061] Moreover, in a direction parallel to the second inner surface 16, the side surface of the submount 40 on the emission end surface side is disposed at a position closer to the first inner surface 15 on the light traveling side than the center of the opposing first inner surface 15. Moreover, in a direction parallel to the second inner surface 16, the side surface of the submount 40 opposite the emission end surface side is disposed at a position closer to the first inner surface 15 on the element side than the center of the opposing first inner surface 15. Therefore, the submount 40 is provided in the space within the recess from the light traveling side to the element side rather than the center.

[0062] Moreover, the submount 40 is disposed such that the center of gravity of the submount 40 in a direction parallel to the second inner side surface 16 is closer to the first inner side surface 15 on the element side than the center of the opposing first inner side surface 15. Therefore, the submount 40 as a whole is provided closer to the element side than to the center in the space within the recess.

[0063] Moreover, the submount 40 is disposed in a position where the light emission end face of the semiconductor laser element 30 is closer to the first outer surface 18 on the light traveling side than the center of the opposing first outer surface 18 in relation to the direction parallel to the second inner surface 16 or the second outer surface 19. Therefore, the light emission end face of the semiconductor laser element 30 is provided on the light traveling side from the center based on the outer shape of the base 10 or the outer shape of the light emitting device 1.

[0064] Further, in the direction parallel to the second inner surface 16 or the second outer surface 19, the submount 40 is positioned such that the side opposite the emission end surface of the semiconductor laser element 30 is closer to the first outer surface 18 on the element side than the center of the opposing first outer surface 18.

[0065] Moreover, in a direction parallel to the second inner surface 16 or the second outer surface 19, the side surface of the submount 40 on the emission end surface side is disposed at a position closer to the first outer surface 18 on the light traveling side than the center of the opposing first outer surface 18. Moreover, in a direction parallel to the second inner surface 16 or the second outer surface 19, the side surface of the submount 40 opposite to the emission end surface side is disposed at a position closer to the first outer surface 18 on the element side than the center of the opposing first outer surface 18. Therefore, the submount 40 is provided from the light traveling side to the element side based on the outer shape of the base 10 or the outer shape of the light emitting device 1, relative to its center.

[0066] Further, the submount 40 is disposed such that the center of gravity of the submount 40 is closer to the first outer surface 18 on the element side than to the center of the opposing first outer surface 18 in a direction parallel to the second inner surface 16 or the second outer surface 19. Therefore, the submount 40 as a whole is provided closer to the element side than to the center based on the outer shape of the base 10 or the outer shape of the light emitting device 1.

[0067] The light reflecting member 50 is disposed so as to be contained in an area on the light traveling side of a plane that passes through the center of the opposing first inner side surface 15 and is parallel to the first inner side surface 15. The light reflecting member 50 is also disposed so as to be contained in an area on the light traveling side of a plane that passes through the center of the opposing first outer side surface 18 and is parallel to the first inner side surface 15 or the first outer side surface 18. In the direction parallel to the second inner side surface 16, the length of the light reflecting member 50 is shorter than the length of the submount 40.

[0068] The first protective element 61 is disposed on the light traveling side of a plane including any one of the emission end faces of the three semiconductor laser elements 30 in relation to the semiconductor laser elements 30. Furthermore, in relation to the submount 40, it is disposed on the light traveling side of a plane including a side surface on the emission end face side of the semiconductor laser elements 30. Furthermore, in relation to the light reflecting member 50, it is disposed on the light traveling side of a straight line including a side that is the lower end of the light reflecting surface in a top view. Furthermore, it intersects with a straight line including a side that is the upper end of the light reflecting surface in a top view. It may also be disposed on the element side of this straight line.

[0069] The second protective element 62 is disposed on the light traveling side of a plane including any one of the emission end faces of the three semiconductor laser elements 30 in relation to the semiconductor laser elements 30. Furthermore, in relation to the submount 40, the second protective element 62 is disposed on the light traveling side of a plane including a side surface on the emission end face side of the semiconductor laser elements 30. Furthermore, in relation to the light reflecting member 50, the second protective element 62 intersects with a line including a side that is the lower end of the light reflecting surface in a top view. Furthermore, the second protective element 62 is disposed on the element side of a line including a side that is the upper end of the light reflecting surface in a top view. The second protective element 62 may also be disposed so as to intersect with a plane including any one of the emission end faces of the semiconductor laser elements 30.

[0070] The third protective element 63 is disposed on the element side relative to the semiconductor laser elements 30 from a plane including any one of the emission end faces of the three semiconductor laser elements 30. Furthermore, in relation to the submount 40, the third protective element 63 is disposed on the element side relative to a plane including a side face on the emission end face side of the semiconductor laser elements 30. Furthermore, the third protective element 63 is disposed on the light traveling side relative to a plane including the side face on the emission end face side and the opposite side. Furthermore, in relation to the light reflecting member 50, the third protective element 63 is disposed on the element side relative to a straight line including a side that is the lower end of the light reflecting surface in a top view. The third protective element 63 may also be disposed so as to intersect with a plane including the side face on the emission end face side and the opposite side.

[0071] Moreover, the thickness from the lower surface to the upper surface of the submount 40 is greater than the height from the bottom surface 12 to the side that is the lower end of the light reflecting surface. Moreover, the height from the bottom surface 12 to the upper surface 21 of the stepped portion is greater than the height from the bottom surface 12 to the upper surface of the semiconductor laser element 30. Therefore, the light emission position at the emission end surface of the semiconductor laser element 30 is higher than the lower end of the light reflecting surface, higher than the upper surface of the submount 40, and lower than the upper surface 21 of the stepped portion. Moreover, the height from the bottom surface 12 to the apex of the light reflecting member 50 is greater than the height from the bottom surface 12 to the upper surface 21 of the stepped portion.

[0072] Next, a plurality of wires 70 are joined to electrically connect the semiconductor laser elements 30. One end of the wires 70 is joined to the upper surface of the semiconductor laser element 30 or the upper surface of the submount 40, and the other end is joined to the upper surface 21 of the stepped portion. Here, since electrode surfaces corresponding to the two emitters are provided on the upper surface, one end of each of the two corresponding wires 70 is joined to the electrode surfaces of the different emitters. Also, one end of one wire 70 is joined to the submount 40 which is electrically connected to the electrode surface on the lower surface side.

[0073] Here, three semiconductor laser elements 30 each having two emitters are prepared, and an electric circuit is designed so that the ON / OFF of light emission can be controlled for each emitter. Therefore, the semiconductor laser elements 30 are wired so that the supply of power supply voltage can be controlled for each emitter. In the light emitting device 1, a total of nine wires 70 are bonded to any of the multiple metal films 25, and each of the nine wires is bonded to a different metal film 25 to establish an electrical connection.

[0074] Furthermore, three wires 70 are connected to one semiconductor laser element 30. One semiconductor laser element 30 is connected to one cathode electrode, and two emitters are connected to different anode electrodes. Also, one emitter and one protective element 60 are connected in parallel. That is, there is a cathode electrode for each semiconductor laser element 30, there is an anode electrode for each emitter, and one protective element 60 is connected to one anode electrode.

[0075] It is also possible to control the semiconductor laser element unit, that is, to control the ON / OFF of the multi-emitter collectively. The number of protective elements and wires is appropriately determined according to the mode of control and the number of semiconductor laser elements. For example, when controlling the semiconductor laser element unit, a configuration in which one protective element 60 and two wires 70 correspond to one semiconductor laser element 30 is also conceivable.

[0076] All three wires 70 electrically connecting the first semiconductor laser element 31 are joined to the metal film 25 on the step upper surface 21 of the first step portion 23. All three wires 70 electrically connecting the second semiconductor laser element 32 are joined to the metal film 25 on the step upper surface 21 of the second step portion 24. Therefore, the three wires 70 electrically connecting the first semiconductor laser element 31 are joined to the metal film 25 on one side of the second inner side surface 16, and the three wires 70 electrically connecting the second semiconductor laser element 32 are joined to the metal film 25 on the other side of the second inner side surface 16.

[0077] Moreover, all of the wires 70 electrically connecting the first semiconductor laser element 31 are not joined to the step upper surface 21 of the step portion 20 formed on the second inner side surface 16 on the side where the second semiconductor laser element 32 is closer than the first semiconductor laser element 31. Similarly, all of the wires 70 electrically connecting the second semiconductor laser element 32 are not joined to the step upper surface 21 of the step portion 20 formed on the second inner side surface 16 on the side where the first semiconductor laser element 31 is closer than the second semiconductor laser element 32. In this way, the risk of the wires crossing and coming into contact can be reduced.

[0078] Of the three wires 70 electrically connecting the third semiconductor laser element 33, one is bonded to the metal film 25 on one side of the second inner side surface 16 and two are bonded to the metal film 25 on the other side of the second inner side surface 16. That is, the wires 70 are stretched in a distributed manner over the first step portion 23 and the second step portion 24.

[0079] Moreover, all of the wires 70 electrically connecting the third semiconductor laser element 33 are joined to the third semiconductor laser element 33 at portions protruding toward the element side beyond the first semiconductor laser element 31 and the second semiconductor laser element 32. That is, the third semiconductor laser element 33 has a longer side than the first semiconductor laser element 31 and the second semiconductor laser element 32, and protrudes on the opposite side to the emission end surface. One end of the wire 70 is joined to the upper surface electrode of the third semiconductor laser element 33 at this protruding portion.

[0080] The other ends of the wires 70 bonded to the semiconductor laser elements 30 or the submount 40 are bonded to the metal film 25 of the step portion 20. In relation to the semiconductor laser elements 30, the wires 70 are bonded closer to the element than a plane including any of the emission end faces of the three semiconductor laser elements 30. In relation to the submount 40, the wires 70 are bonded closer to the element than a plane including a side face on the emission end face side of the semiconductor laser elements 30.

[0081] Moreover, the multiple wires 70 joined to the semiconductor laser element 30 or the submount 40 are not joined on the light traveling side of a straight line including a side that becomes the lower end of the light reflecting surface in a top view in relation to the light reflecting member 50. Also, they are not joined on the light traveling side of a straight line including a side that becomes the upper end of the light reflecting surface in a top view. Also, the multiple wires 70 are stretched so as not to overlap the light reflecting surface in a top view.

[0082] One end of the wire 70 is joined to the upper surface of the submount 40 or the upper surface of the semiconductor laser element 30, and the other end is joined to the stepped portion upper surface 21, which is located higher than the upper surface of the submount 40 or the upper surface of the semiconductor laser element 30. Therefore, if the wire 70 overlaps with the light reflecting surface in a top view, it is considered that part of the light reflected by the light reflecting surface will be blocked by the wire 70. Therefore, it is preferable that the wire 70 is not on the path of the light. One method for this is to join the wire 70 on the element side rather than the plane including the light emitting end face, and the wire 70 is joined in this manner in the light emitting device 1. The stepped portion upper surface 21 may be located at a lower position.

[0083] In order to join the wire 70 in this manner, in the light emitting device 1, the protective element 60 is disposed at a position closer to the edge than to the central region of the stepped portion upper surface 21. Specifically, the first protective element 61 and the second protective element 62 are disposed closer to the light traveling side, and the third protective element 63 is disposed closer to the element side. By disposing at least one or more protective elements 60 in a region that is not desirable for joining the wire 70, a wiring pattern with less waste can be realized.

[0084] One of the wires 70 electrically connecting the first semiconductor laser element 31 is bonded to the metal film 25 on which the protection element 60 is disposed. One of the wires 70 electrically connecting the second semiconductor laser element 32 is bonded to the metal film 25 on which the protection element 60 is disposed. Specifically, both are bonded to the metal film 25 on which the second protection element 62 is disposed.

[0085] The three wires 70 electrically connecting the third semiconductor laser element 33 are bonded to the metal film 25 on which the protection element 60 is disposed. In addition, the two wires 70 corresponding to the two emitters are bonded to the metal film 25 on which the protection element 60 is disposed. Specifically, they are bonded to the metal film 25 on which the third protection element 63 is disposed. In other words, among the multiple metal films 25, there is a metal film 25 to which the protection element 60 and the wires 70 are bonded.

[0086] The first protective element 61 and the second protective element 62 arranged on the step upper surface 21 of the step portion 20 (first step portion 23) formed on the second inner side surface 16 to which the wire 70 electrically connecting the first semiconductor laser element 31 is joined protect the first semiconductor laser element 31. The first protective element 61 and the second protective element 62 arranged on the step upper surface 21 of the step portion 20 (second step portion 24) formed on the second inner side surface 16 to which the wire 70 electrically connecting the second semiconductor laser element 32 is joined protect the second semiconductor laser element 32. The two third protective elements 63 arranged on the step upper surface 21 of the step portion 20 (first step portion 23 and second step portion 24) formed on the two second inner side surfaces 16 protect the third semiconductor laser element 33.

[0087] Between the first protective element 61 and the second protective element 62 arranged on the step upper surface 21 of one step portion 20 (either the first step portion 23 or the second step portion 24), there is no region to which the wire 70 bonded to the semiconductor laser element 30 is bonded. Similarly, there is no region between them to which the wire 70 bonded to the submount 40 is bonded.

[0088] In the light emitting device 1 thus arranged, it is possible to draw a straight line that is parallel to the first inner side surface 15 and intersects with the light reflecting member 50 and the first protective element 61 in a top view. In other words, in the light emitting device 1, the light reflecting member 50 and the one or more first protective elements 61 are arranged so as to intersect with a single straight line parallel to the first inner side surface 15. By arranging the first protective element 61 in a region where it is not desirable to join the wire 70, it is possible to realize a wiring pattern that makes effective use of the stepped portion upper surface 21 and contributes to miniaturization.

[0089] Therefore, in the light emitting device 1, the protective element 60 (first protective element 61) disposed on the furthest light traveling side and the light reflecting member 50 are disposed so as to intersect with one straight line parallel to the first inner surface 15. Alternatively, the protective element 60 disposed on the furthest light traveling side intersects with a straight line parallel to the first inner surface 15 and passing through at least somewhere on the light reflecting member 50. The same is true for the step portions 20 formed on the two second inner surfaces 16.

[0090] Furthermore, in the light emitting device 1, it is possible to draw a straight line that is parallel to the first inner side surface 15 in a top view and that intersects with the light reflecting member 50 and the second protective elements 62. In other words, in the light emitting device 1, the light reflecting member 50 and the one or more second protective elements 62 are disposed so as to intersect with one straight line parallel to the first inner side surface 15.

[0091] Therefore, in the light emitting device 1, all of the protection elements 60 arranged on the light traveling side of the center of the opposing first inner side surface 15 in the direction parallel to the second inner side surface 16 and the light reflecting member 50 are arranged so as to intersect with one straight line parallel to the first inner side surface 15. Alternatively, all of the protection elements 60 arranged on the light traveling side of the center of the opposing first inner side surface 15 in the direction parallel to the second inner side surface 16 intersect with a straight line parallel to the first inner side surface 15 and passing at least somewhere on the light reflecting member 50. This also applies to the step portions 20 formed on the two second inner side surfaces 16.

[0092] In this way, based on the positional relationship of the light reflecting member 50, the areas that are not desirable for bonding the wire 70 are symmetrical in the step portions 20 formed on the two second inner sides 16. Therefore, by providing a plurality of metal films symmetrically on the upper surfaces 21 of the respective step portions, a wiring pattern that makes effective use of the area is realized.

[0093] Next, the lid member 80 is bonded to the upper surface of the base 10. Metal films provided in the bonding regions of the lid member 80 and the base 10 are bonded to each other via Au-Sn or the like, and fixed. At this time, the base 10 and the lid member 80 are bonded so that the space in which the semiconductor laser element 30 is disposed becomes a hermetically sealed closed space. By hermetically sealing in this manner, it is possible to suppress the collection of organic matter and the like on the light emitting end face of the semiconductor laser element 30.

[0094] The cover member 80 also serves as a light-transmitting member that transmits light reflected by the light reflecting surface of the light reflecting member 50. Here, the light-transmitting property means that the transmittance of the light emitted from the semiconductor laser element 30 and incident on the light-transmitting member is 80% or more.

[0095] In this way, the light emitting device according to the embodiment can be designed to have a compact outer shape while arranging multiple semiconductor laser elements and multiple protective elements in the cavity of the base that forms the outer shape. In addition, a suitable wiring pattern for this purpose is realized in the base. In addition, since the arrangement of the components is designed with consideration for the optical path, the function as a light emitting device is not impaired.

[0096] Although the light emitting device according to the embodiment has been described above, the light emitting device according to the present invention is not strictly limited to the light emitting device of the embodiment. In other words, the present invention can be realized without being limited to the external shape and structure of the light emitting device disclosed in the embodiment. In addition, the present invention can be applied without necessarily having all the components. For example, if some of the components of the light emitting device disclosed in the embodiment are not described in the claims, the freedom of design by those skilled in the art, such as substitution, omission, modification of the shape, and change of the material, is recognized for those some components, and the invention described in the claims is specified to be applied. [Industrial Applicability]

[0097] The light emitting device described in each embodiment can be used in head mounted displays, projectors, vehicle headlights, lighting, displays, and the like. [Explanation of symbols]

[0098] 1(1A) Light-emitting device 10 base 11 Top side 12 Bottom 13 Bottom side 14 Inner surface 15 1st inner surface 16 Second inner surface 17 External surface 18 First outer surface 19 Second outer surface 20 Step 21 Top surface of step part 22 Side of step part 23 First step 24 Second step 25 Metal Film 30 Semiconductor laser element 31 First semiconductor laser element 32 Second semiconductor laser element 33 Third semiconductor laser element 40 Submount 50 Light reflecting material 60 Protection element 61 First protection element 62 Second protection element 63 Third protection element 70, 71 Wire 80 Lid member

Claims

1. a base having a bottom surface; a frame portion having two first inner side surfaces facing each other in a first direction with the bottom surface in between, two second inner side surfaces facing each other in a second direction with the bottom surface in between, a first step portion provided along one of the two second inner side surfaces, a second step portion provided along the other second inner side surface, a plurality of first metal films provided on the first step portions, and a plurality of second metal films provided on the second step portions; a plurality of semiconductor laser elements including a first semiconductor laser element that emits light traveling in a first direction from an emission end surface toward the first inner side surface, a second semiconductor laser element that is disposed adjacent to the first semiconductor laser element and emits light traveling in the first direction, and a third semiconductor laser element that is disposed adjacent to the second semiconductor laser element and emits light traveling in the first direction; one or more submounts having a metal film on an upper surface thereof, the plurality of semiconductor laser elements being disposed on the metal film; one or more light reflecting members that reflect light emitted from the plurality of semiconductor laser elements; a plurality of wires, each of which is bonded to one of the plurality of metal films, for electrically connecting the one or more semiconductor laser elements to the base; having the first semiconductor laser element is disposed at a position closer to the first step portion than the second semiconductor laser element; the third semiconductor laser element is disposed at a position closer to the second step portion than the second semiconductor laser element, the plurality of wires include a first wire bonded to the third semiconductor laser element and a second wire bonded to the metal film of the submount on which the third semiconductor laser element is disposed, the first wire or the second wire is joined to the metal film provided on the first step portion.

2. The light emitting device according to claim 1 , wherein the first wire is joined to the metal film provided on the first step portion.

3. The light emitting device according to claim 2 , wherein the first wire is longer than the second wire in a top view.

4. The light emitting device according to claim 1 , wherein the first wire is joined to the metal film provided on the second step portion.

5. The light emitting device according to claim 1 , wherein the second wire is joined to the metal film provided on the first step portion.

6. 6. The light-emitting device according to claim 1, wherein the first wire or the second wire is joined to the metal film provided on the first step portion at a position away in a second direction, which is opposite to the first direction, from a plane including a side surface of the first semiconductor laser element opposite the emission end surface.

7. 7. The light emitting device according to claim 1, wherein the first wire is joined to the metal film provided on the first step portion or the second step portion at a position away in a second direction, which is opposite to the first direction, from a plane including a side surface of the third semiconductor laser element opposite the emission end surface.

8. the plurality of wires includes a third wire joined to the first semiconductor laser element, The light emitting device according to claim 1 , wherein the third wire is joined to the metal film provided on the first step portion.

9. The light-emitting device of claim 8, wherein the first wire or the second wire that is joined to the metal film provided on the first step portion is joined to the metal film provided on the first step portion at a position away from the third wire in a second direction, which is the opposite direction to the first direction, when viewed from above.

10. The light emitting device according to claim 1 , wherein the one or more submounts are constituted by a plurality of submounts on which the plurality of semiconductor laser elements are separately arranged.

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