JP2011009305A - Light-emitting module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration of luminous intensity or luminance when light is incident on an optical wavelength conversion material from a light-emitting element.SOLUTION: In a light-emitting module 40, an optical wavelength conversion member 50 is formed in a plate shape and arranged such that an incident surface 50a faces a light-emitting surface 48a of a semiconductor light-emitting element 48. The optical wavelength conversion member 50 converts a wavelength of light incident from the incident surface 50a and emits the converted light. Recessed and projecting parts are formed on the incident surface 50a of the optical wavelength conversion member 50. An adhesive layer 52 is formed between the light-emitting surface 48a of the semiconductor light-emitting element 48 and the incident surface 50a of the optical wavelength conversion member 50. The adhesive layer 52 is formed to get into the recessed parts of the incident surface 50a and fixes the semiconductor light-emitting element 48 and the optical wavelength conversion member 50 to each other.

Description

  The present invention relates to a light emitting module, and more particularly, to a light emitting module including a light emitting element and an optical wavelength conversion member that converts the wavelength of light emitted from the light emitting element.

  2. Description of the Related Art Conventionally, a technique for obtaining a light emitting module that emits light of a color different from the color of light emitted by an LED by converting the wavelength of light emitted by an LED (Light Emitting Diode) using a phosphor or the like is known. (For example, refer to Patent Document 1). For example, in order to increase the conversion efficiency, a technique has been proposed in which a ceramic layer containing a wavelength conversion material is disposed in the path of light emitted by a light emitting layer (see, for example, Patent Document 2).

JP 2007-59864 A JP 2006-5367 A

  In recent years, the use of LEDs has been spreading more and more, and for example, it is also expected as a use for vehicle headlamps. However, in order to use in such applications, it is necessary to realize a high-luminance or high-luminance LED. For this purpose, the improvement of the extraction efficiency of the light emitted from the LED is a big problem. In the technique described in the above-mentioned patent document, since light emitted from the light emitting element is emitted through the light wavelength conversion material, the light emitting element is changed from the light emitting element to the light wavelength conversion material. It is necessary to suppress a decrease in luminous intensity or luminance when light enters.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to suppress a decrease in luminous intensity or luminance when light enters a light wavelength conversion material from a light emitting element.

  In order to solve the above problems, a light emitting module according to an aspect of the present invention is arranged such that an incident surface faces a light emitting element and a light emitting surface of the light emitting element, and the light incident from the incident surface is wavelength-converted and emitted. A plate-like light wavelength conversion member. Concavities and convexities are provided on the light emitting surface of the light emitting element or the incident surface of the light wavelength conversion member.

  According to this aspect, it is possible to suppress a decrease in light extraction efficiency when light enters the light wavelength conversion material from the light emitting element. For this reason, it can avoid that the luminous intensity or the brightness | luminance of the light which a light emitting module emits by providing an optical wavelength conversion member falls.

  The light emitting surface of the light emitting element and the incident surface of the light wavelength conversion member may be bonded to each other by direct bonding.

  For example, when both are fixed via an adhesive layer, the light extraction efficiency may decrease when light enters the light wavelength conversion material from the light emitting element due to the influence of the refractive index of the adhesive layer. According to this aspect, it is possible to increase the light extraction efficiency as compared with the case where both are fixed through the adhesive layer. For this reason, it is possible to suppress a decrease in luminous intensity or luminance when light enters the light wavelength conversion material from the light emitting element.

  You may further provide the buffer layer formed in the light emission surface of the light emitting element, or the incident surface of the light wavelength conversion member in order to adhere a light emitting element and a light wavelength conversion member mutually using direct joining. The buffer layer may be formed on the convex portion so that an opening penetrating the concave portion is formed.

  By providing the buffer layer, direct bonding can be more easily performed. However, since the translucency of the buffer layer may be lower than that of the light wavelength conversion member, when the buffer layer is provided, it is necessary to suppress a decrease in light extraction efficiency due to the buffer layer. According to this aspect, by forming the buffer layer on the convex portion to be directly joined, and providing the opening that penetrates the concave portion, it is possible to secure a region through which light can pass without passing through the buffer layer. . For this reason, it is possible to suppress a decrease in light extraction efficiency due to the buffer layer itself.

  Another embodiment of the present invention is also a light emitting module. The light emitting module includes a light emitting element, a plate-shaped light wavelength conversion member that is arranged so that an incident surface faces the light emitting surface of the light emitting element, converts the wavelength of light incident from the incident surface, and emits light. A photonic crystal interposed between the surface and the incident surface of the light wavelength conversion member.

  According to this aspect, it is possible to easily reduce the light extraction efficiency when light is incident on the light wavelength conversion material from the light emitting element by utilizing the characteristic of the photonic crystal that is a structure whose refractive index changes periodically. Can be suppressed. For this reason, it can avoid that the luminous intensity or the brightness | luminance of the light which a light emitting module emits by providing an optical wavelength conversion member falls.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of luminous intensity or a brightness | luminance when light injects into a light wavelength conversion material from a light emitting element can be suppressed.

It is sectional drawing which shows the structure of the vehicle headlamp which concerns on 1st Embodiment. It is a figure which shows the structure of the light emitting module board | substrate which concerns on 1st Embodiment. It is a side view of the light emitting module which concerns on 1st Embodiment. It is a side view of the light emitting module which concerns on 2nd Embodiment. It is a side view of the light emitting module which concerns on 3rd Embodiment. It is a side view of the light emitting module which concerns on 4th Embodiment. It is a side view of the light emitting module which concerns on 5th Embodiment. It is a side view of the light emitting module which concerns on 6th Embodiment. It is a side view of the light emitting module which concerns on 7th Embodiment. It is a side view of the light emitting module which concerns on 8th Embodiment. It is a side view of the light emitting module which concerns on 9th Embodiment. It is a side view of the light emitting module which concerns on 10th Embodiment. It is a side view of the light emitting module which concerns on 11th Embodiment. It is a side view of the light emitting module which concerns on 12th Embodiment.

  Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration of a vehicle headlamp 10 according to the first embodiment. The vehicle headlamp 10 includes a lamp body 12, a front cover 14, and a lamp unit 16. Hereinafter, the left side in FIG. 1 will be described as the front of the lamp, and the right side will be described as the rear of the lamp. Further, the right side of the lamp in front of the lamp is called the right side of the lamp, and the left side is called the left side of the lamp. FIG. 1 shows a cross section of a vehicle headlamp 10 cut by a vertical plane including the optical axis of the lamp unit 16 as viewed from the left side of the lamp. When the vehicle headlamp 10 is mounted on the vehicle, the vehicle headlamps 10 formed symmetrically with each other are provided on the vehicle left front and right front, respectively. FIG. 1 shows the configuration of the left or right vehicle headlamp 10.

  The lamp body 12 is formed in a box shape having an opening. The front cover 14 is formed in a bowl shape with a translucent resin or glass. The front cover 14 has an edge attached to the opening of the lamp body 12. In this way, a lamp chamber is formed in an area covered by the lamp body 12 and the front cover 14.

  A lamp unit 16 is disposed in the lamp chamber. The lamp unit 16 is fixed to the lamp body 12 by an aiming screw 18. The lower aiming screw 18 is configured to rotate when the leveling actuator 20 is operated. For this reason, it is possible to move the optical axis of the lamp unit 16 in the vertical direction by operating the leveling actuator 20.

  The lamp unit 16 includes a projection lens 30, a support member 32, a reflector 34, a bracket 36, a light emitting module substrate 38, and heat radiating fins 42. The projection lens 30 is a plano-convex aspheric lens having a convex front surface and a flat rear surface, and projects a light source image formed on the rear focal plane as a reverse image to the front of the lamp. The support member 32 supports the projection lens 30. A light emitting module 40 is provided on the light emitting module substrate 38. The reflector 34 reflects light from the light emitting module 40 and forms a light source image on the rear focal plane of the projection lens 30. Thus, the reflector 34 and the projection lens 30 function as an optical member that condenses the light emitted from the light emitting module 40 toward the front of the lamp. The radiation fins 42 are attached to the rear surface of the bracket 36 and mainly radiate heat generated by the light emitting module 40.

  The support member 32 is formed with a shade 32a. The vehicle headlamp 10 is used as a low beam light source, and the shade 32a blocks a part of the light emitted from the light emitting module 40 and reflected by the reflector 34, so that the cut-off line in the low beam light distribution pattern in front of the vehicle. Form. Since the low beam light distribution pattern is known, the description thereof is omitted.

  FIG. 2 is a diagram illustrating a configuration of the light emitting module substrate 38 according to the first embodiment. The light emitting module substrate 38 includes a light emitting module 40, a substrate 44, a submount 45, and a transparent cover 46. The light emitting module 40 is attached to a submount 45, and the submount 45 is attached to the substrate 44. The light emitting module 40 is covered with a colorless transparent cover 46, and the inside of the transparent cover 46 is hollow. The light emitting module 40 includes a semiconductor light emitting element 48 and an optical wavelength conversion member 50.

FIG. 3 is a side view of the light emitting module 40 according to the first embodiment. The semiconductor light emitting element 48 is configured by an LED element. In the first embodiment, a blue LED that mainly emits light having a blue wavelength is employed as the semiconductor light emitting element 48. Specifically, the semiconductor light emitting element _{48, Al x In y Ga (1} -x-y) Al a N type semiconductor layer is formed by crystal growth _{x In y Ga (1-x} -y) N based It is comprised by the LED element. The material for forming the semiconductor light emitting element 48 is not limited to this, and may be any one of InN, AlGaN, and AIN, for example.

  The semiconductor light emitting element 48 is formed as a 1 mm square chip, for example, and is provided so that the center wavelength of the emitted blue light is 460 nm. Of course, the configuration of the semiconductor light emitting element 48 and the wavelength of emitted light are not limited to those described above, and the semiconductor light emitting element 48 may be one that mainly emits light of a wavelength other than blue.

  A so-called flip chip type semiconductor light emitting device 48 is employed. Of course, other types of semiconductor light emitting elements 48 may be employed, and for example, a so-called vertical chip type or a so-called face-up type may be employed for the semiconductor light emitting element 48. .

  The semiconductor light emitting device 48 includes a semiconductor layer 54 and a crystal growth substrate 56 used for crystal growth of the semiconductor layer 54. The crystal growth substrate 56 is made of sapphire. Of course, the material of the crystal growth substrate 56 is not limited to sapphire, and other materials used for crystal growth may be employed. Since the semiconductor layer 54 is formed by crystal growth on the crystal growth substrate 56, the semiconductor layer 54 and the crystal growth substrate 56 are fixed to each other. In the semiconductor light emitting device 48, the surface opposite to the surface fixed to the semiconductor layer 54 of the outer surface of the crystal growth substrate 56 is a light emitting surface 48a. The light emitting surface 48a is formed in a planar shape. The semiconductor light emitting device 48 may be a semiconductor light emitting device in which a semiconductor layer is grown on a crystal growth substrate and then the crystal growth substrate is removed.

  The light wavelength conversion member 50 is a so-called luminescent ceramic or fluorescent ceramic, and sinters a ceramic base made of YAG (Yttrium Aluminum Garnet) powder, which is a phosphor excited by blue light. Can be obtained. Since the manufacturing method of such a light wavelength conversion ceramic is well-known, detailed description is abbreviate | omitted. The light wavelength conversion member 50 is not limited to a sintered ceramic, and includes, for example, amorphous, polycrystalline, or single crystal, and is not limited by the crystal structure. The light wavelength conversion member 50 is formed in a plate shape.

  Further, a transparent material is used for the light wavelength conversion member 50. In the first embodiment, “transparent” means that the total light transmittance of light in the conversion wavelength region is 40% or more. As a result of the inventor's earnest research and development, if the total light transmittance of light in the conversion wavelength range is 40% or more in a transparent state, the light wavelength conversion member 50 can appropriately convert the wavelength of light, It has been found that a decrease in the intensity of light passing therethrough can be appropriately suppressed. Therefore, the light emitted from the semiconductor light emitting device 48 can be more efficiently converted by making the light wavelength conversion member 50 transparent.

  Further, the light wavelength conversion member 50 is made of an organic binderless inorganic material, and durability is improved as compared with a case where an organic material such as an organic binder is contained. For this reason, for example, it is possible to input power of 1 W (watt) or more to the light emitting module 40, and it is possible to increase the luminance, luminous intensity, and luminous flux of the light emitted from the light emitting module 40. The light wavelength conversion member 50 may contain a binder.

  The light wavelength conversion member 50 is disposed so that the incident surface 50a faces the light emitting surface 48a of the semiconductor light emitting device 48, and the light incident from the incident surface 50a is wavelength-converted and emitted. The light wavelength conversion member 50 converts the wavelength of blue light mainly emitted from the semiconductor light emitting element 48 and emits yellow light. For this reason, the light emitting module 40 emits white light that is a combined light of the blue light that has passed through the light wavelength conversion member 50 and the yellow light that has been wavelength-converted by the light wavelength conversion member 50 and emitted.

  In the first embodiment, the incident surface 50 a of the light wavelength conversion member 50 is provided with unevenness. By providing such irregularities, light reflected by the incident surface 50a can be suppressed, and a decrease in light extraction efficiency due to the provision of the light wavelength conversion member 50 can be suppressed.

  An adhesive layer 52 is provided between the light emitting surface 48 a of the semiconductor light emitting device 48 and the incident surface 50 a of the light wavelength conversion member 50. The adhesive layer 52 is made of, for example, a silicon or organic material, and fixes the semiconductor light emitting element 48 and the light wavelength conversion member 50 to each other. At this time, the adhesive layer 52 is provided so as to enter the concave portion of the incident surface 50a.

  Of course, the concave and convex shape is not limited to the shape shown in FIG. 3, and a concave or convex portion having a triangular cross section may be provided, and a concave or convex portion whose bottom is a curved surface is curved. The convex part which becomes may be provided.

  Further, a photonic crystal may be provided on the incident surface 50a instead of the unevenness. Also in this case, the adhesive layer 52 may be provided between the light emitting surface 48a and the incident surface 50a. Thereby, a photonic crystal can be interposed between the light emitting surface 48 a of the semiconductor light emitting device 48 and the incident surface 50 a of the light wavelength conversion member 50. A photonic crystal is a structure whose refractive index changes periodically. Since the photonic crystal is well-known, the description about the formation method etc. is abbreviate | omitted. Providing the photonic crystal in this manner can also suppress the reflection of light from the incident surface 50a, and suppress the decrease in light extraction efficiency when light enters the light wavelength conversion member 50 from the semiconductor light emitting element 48. can do.

(Second Embodiment)
FIG. 4 is a side view of the light emitting module 60 according to the second embodiment. The configuration of the vehicular headlamp 10 is the same as that of the first embodiment except that a light emitting module 60 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  The light emitting module 60 includes a semiconductor light emitting element 62 and an optical wavelength conversion member 64. In the second embodiment, the semiconductor light emitting device 62 also includes a semiconductor layer 68 and a crystal growth substrate 70 used for crystal growth of the semiconductor layer 68. In the semiconductor light emitting element 62, the surface opposite to the surface fixed to the semiconductor layer 68 among the outer surfaces of the crystal growth substrate 70 is the light emitting surface 62a. The semiconductor light emitting element 62 may be used in which a semiconductor layer is grown on a crystal growth substrate and then the crystal growth substrate is removed.

  The materials of the semiconductor layer 68 and the crystal growth substrate 70 are the same as those of the semiconductor layer 54 and the crystal growth substrate 56 according to the first embodiment. For this reason, the semiconductor light emitting element 62 is also provided so as to emit mainly blue light.

  The light wavelength conversion member 64 is disposed so that the incident surface 64a faces the light emitting surface 62a of the semiconductor light emitting element 62, and the light incident from the incident surface 64a is wavelength-converted and emitted. The incident surface 64a is formed in a flat shape. The material of the light wavelength conversion member 64 is also the same as that of the light wavelength conversion member 50 according to the first embodiment. Therefore, the light wavelength conversion member 64 is also provided so as to emit blue light by converting the wavelength of blue light. Therefore, the semiconductor light emitting element 62 also emits white light that is a combined light of blue light and yellow light.

  The light emitting module 60 is a so-called flip chip type as in the first embodiment. However, it is of course not limited to this, and for example, a vertical chip type or a so-called face-up type may be employed.

  In the second embodiment, irregularities are provided on the light emitting surface 62 a of the semiconductor light emitting element 62, that is, on the outer surface of the crystal growth substrate 70. When the crystal growth substrate is removed, the outer surface of the semiconductor layer 68, that is, the epi layer may be provided with unevenness. By providing the light emitting surface 62a with irregularities in this way, it is possible to suppress a decrease in light extraction efficiency when light enters the light incident surface 64a of the light wavelength conversion member 64 from the light emitting surface 62a of the semiconductor light emitting element 62. .

  An adhesive layer 66 is provided between the light emitting surface 62 a of the semiconductor light emitting element 62 and the incident surface 64 a of the light wavelength conversion member 64. The material of the adhesive layer 66 is the same as that of the semiconductor layer 54 according to the first embodiment. The adhesive layer 66 fixes the semiconductor light emitting element 62 and the light wavelength conversion member 64 to each other. At this time, the adhesive layer 66 is provided so as to enter the concave portion of the light emitting surface 62a.

  Further, a photonic crystal may be provided on the light emitting surface 62a instead of the unevenness. Also in this case, the adhesive layer 66 may be provided between the light emitting surface 62a and the incident surface 64a. Light is incident on the light wavelength conversion member 64 from the semiconductor light emitting device 62 by interposing a photonic crystal between the light emitting surface 62a of the semiconductor light emitting device 62 and the incident surface 64a of the light wavelength conversion member 64 in this manner. Sometimes it is possible to suppress a decrease in light extraction efficiency.

(Third embodiment)
FIG. 5 is a side view of the light emitting module 80 according to the third embodiment. The configuration of the vehicular headlamp 10 is the same as that of the first embodiment except that a light emitting module 80 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The light emitting module 80 includes a semiconductor light emitting element 82 and an optical wavelength conversion member 84. In the third embodiment, the semiconductor light emitting device 82 also includes a semiconductor layer 88 and a crystal growth substrate 90 used for crystal growth of the semiconductor layer 88. In the semiconductor light emitting element 82, the surface opposite to the surface fixed to the semiconductor layer 88 among the outer surfaces of the crystal growth substrate 90 is the light emitting surface 82a. The semiconductor light-emitting element 82 may be used in which a semiconductor layer is grown on a crystal growth substrate and then the crystal growth substrate is removed.

  The materials of the semiconductor layer 88 and the crystal growth substrate 90 are the same as those of the semiconductor layer 54 and the crystal growth substrate 56 according to the first embodiment. Therefore, the semiconductor light emitting element 82 is also provided so as to emit mainly blue light.

  The light wavelength conversion member 84 is disposed so that the incident surface 84a faces the light emitting surface 82a of the semiconductor light emitting element 82, and the light incident from the incident surface 84a is wavelength-converted and emitted. The material of the light wavelength conversion member 84 is also the same as that of the light wavelength conversion member 50 according to the first embodiment. For this reason, the light wavelength conversion member 84 is also provided so as to emit yellow light by converting the wavelength of blue light. Therefore, the semiconductor light emitting element 82 also emits white light that is a combined light of blue light and yellow light.

  As in the first embodiment, a so-called flip chip type light emitting module 80 is employed. However, it is of course not limited to this, and for example, a vertical chip type or a so-called face-up type may be employed.

  In the third embodiment, irregularities are provided on both the incident surface 84 a of the light wavelength conversion member 84 and the light emitting surface 82 a of the semiconductor light emitting element 82, that is, the outer surface of the crystal growth substrate 90. In the case where the substrate for crystal growth is removed, the outer surface of the semiconductor layer 88, that is, the epi layer may be provided with unevenness. As described above, by providing irregularities on both the light emitting surface 82 a of the semiconductor light emitting element 82 and the incident surface 84 a of the light wavelength converting member 84, the light emitting surface 82 a of the semiconductor light emitting element 82 is changed to the incident surface 84 a of the light wavelength converting member 84. It is possible to suppress a reduction in light extraction efficiency when light enters.

  An adhesive layer 86 is provided between the light emitting surface 82 a of the semiconductor light emitting element 82 and the incident surface 84 a of the light wavelength conversion member 84. The material of the adhesive layer 86 is the same as that of the semiconductor layer 54 according to the first embodiment. The adhesive layer 86 fixes the semiconductor light emitting element 82 and the light wavelength conversion member 84 to each other. At this time, the adhesive layer 86 is provided so as to enter the recesses of both the light emitting surface 82 a of the semiconductor light emitting element 82 and the incident surface 84 a of the light wavelength conversion member 84.

  Further, in place of the unevenness, a photonic crystal may be provided on both the light emitting surface 82 a of the semiconductor light emitting element 82 and the incident surface 84 a of the light wavelength conversion member 84. Also in this case, an adhesive layer 86 may be provided between the light emitting surface 82a and the incident surface 84a. By interposing a photonic crystal between the light emitting surface 82a of the semiconductor light emitting element 82 and the incident surface 84a of the light wavelength conversion member 84 in this manner, reflection of light by the incident surface 84a can be suppressed, and the semiconductor When light enters the light wavelength conversion member 84 from the light emitting element 82, a decrease in light extraction efficiency can be suppressed.

(Fourth embodiment)
FIG. 6 is a side view of the light emitting module 100 according to the fourth embodiment. The configuration of the vehicle headlamp 10 is the same as that of the first embodiment except that the light emitting module 100 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the light emitting module 100, instead of the adhesive layer 52, the light emitting surface 48a of the semiconductor light emitting element 48 and the light incident surface 50a of the light wavelength conversion member 50 are mutually connected by the adhesive 102 applied so as to enter the concave portion of the incident surface 50a. Except for being fixed, it is configured in the same manner as the light emitting module 60 according to the first embodiment. The material of the adhesive 102 is the same as that of the adhesive layer 52 according to the first embodiment.

  Thereby, the light wavelength conversion member 50 and the semiconductor light emitting element 48 can be fixed to each other in a state where the tip of the convex portion provided on the incident surface 50a is in contact with the light emitting surface 48a. The adhesive 102 is generated from a material having a lower refractive index than the crystal growth substrate 56 and the light wavelength conversion member 50. For this reason, the light incident on the adhesive 102 is less likely to enter the light wavelength conversion member 50 having a higher refractive index than the adhesive 102. As described above, the light emitting surface 48 a is brought into contact with the tip of the convex portion of the incident surface 50 a, so that the portion where the light wavelength conversion member 50 and the semiconductor light emitting device 48 come into contact with each other without using the adhesive 102. The light emitted by 48 can enter the light wavelength conversion member 50. For this reason, compared with the case where an adhesive bond layer is provided between the semiconductor light emitting element 48 and the light wavelength conversion member 50, light can be incident on the light wavelength conversion member 50 with higher efficiency.

(Fifth embodiment)
FIG. 7 is a side view of the light emitting module 120 according to the fifth embodiment. The configuration of the vehicle headlamp 10 is the same as that of the first embodiment except that the light emitting module 120 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the light emitting module 120, the light emitting surface 62 a of the semiconductor light emitting element 62 and the light wavelength conversion member 64 are made incident by the adhesive 122 applied so as to enter the recess of the light emitting surface 62 a of the semiconductor light emitting element 62 instead of the adhesive layer 66. Except that the surface 64a is fixed to each other, the light emitting module 60 according to the second embodiment is configured in the same manner. The material of the adhesive 122 is the same as that of the adhesive layer 52 according to the first embodiment.

  Also by this, the light emitted from the semiconductor light emitting element 62 can be incident on the light wavelength converting member 64 without using the adhesive 122 at the portion where the light wavelength converting member 64 and the semiconductor light emitting element 62 abut. For this reason, compared with the case where an adhesive bond layer is provided between the semiconductor light emitting element 62 and the light wavelength conversion member 64, light can be incident on the light wavelength conversion member 64 with higher efficiency.

(Sixth embodiment)
FIG. 8 is a side view of the light emitting module 140 according to the sixth embodiment. The configuration of the vehicle headlamp 10 is the same as that of the first embodiment except that the light emitting module 140 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The semiconductor light emitting element 82 and the light wavelength conversion member 84 are formed with concavities and convexities so that the tips of the convex portions provided on each of the semiconductor light emitting element 82 and the light wavelength conversion member 84 abut each other. Accordingly, the recesses of both the semiconductor light emitting element 82 and the light wavelength conversion member 84 communicate with each other.

  In the light emitting module 140, the semiconductor light emitting element 82 is replaced by the adhesive 142 applied so as to enter the recesses of both the incident surface 84 a of the light wavelength conversion member 84 and the light emitting surface 82 a of the semiconductor light emitting element 82 instead of the adhesive layer 86. The light emitting surface 82a and the light incident surface 84a of the light wavelength conversion member 84 are configured in the same manner as the light emitting module 80 according to the third embodiment except that they are fixed to each other. The material of the adhesive 142 is the same as that of the adhesive layer 52 according to the first embodiment.

  Also by this, the light emitted from the semiconductor light emitting element 82 can be incident on the light wavelength converting member 84 without using the adhesive 142 in the portion where the light wavelength converting member 84 and the semiconductor light emitting element 82 abut. For this reason, compared with the case where an adhesive bond layer is provided between the semiconductor light-emitting element 82 and the light wavelength conversion member 84, light can be incident on the light wavelength conversion member 84 with higher efficiency.

(Seventh embodiment)
FIG. 9 is a side view of the light emitting module 160 according to the seventh embodiment. The configuration of the vehicle headlamp 10 is the same as that of the first embodiment except that a light emitting module 160 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The light emitting module 160 is the same as the light emitting module 100 according to the fourth embodiment, except that the light emitting surface 48a of the semiconductor light emitting element 48 and the incident surface 50a of the light wavelength conversion member 50 are joined to each other by direct joining instead of an adhesive. Configured.

  As a result of experiments conducted by the inventors, it was confirmed that the semiconductor light emitting device 48 and the light wavelength conversion member 50 can be directly bonded by surface activated bonding. It has also been confirmed that both can be directly bonded by plasma bonding. In this way, for example, by bonding the semiconductor light emitting element 48 and the light wavelength conversion member 50 to each other using direct bonding without using a silicon-based or organic-based adhesive, deterioration of the fixed portion can be avoided. Further, it is possible to avoid a reduction in the extraction efficiency of light emitted from the semiconductor light emitting device 48.

(Eighth embodiment)
FIG. 10 is a side view of the light emitting module 180 according to the eighth embodiment. The configuration of the vehicle headlamp 10 is the same as that of the first embodiment except that a light emitting module 180 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The light emitting module 180 is the same as the light emitting module 120 according to the fifth embodiment except that the light emitting surface 62a of the semiconductor light emitting element 62 and the incident surface 64a of the light wavelength conversion member 64 are bonded to each other by direct bonding instead of an adhesive. Configured. The direct bonding method, the material of the semiconductor light emitting element 62 and the light wavelength conversion member 64 are the same as those in the seventh embodiment.

  Also by this, the light emitted from the semiconductor light emitting element 62 can be incident on the light wavelength conversion member 64 without using an adhesive. For this reason, compared with the case where an adhesive bond layer is provided between the semiconductor light emitting element 62 and the light wavelength conversion member 64, light can be incident on the light wavelength conversion member 64 with higher efficiency.

(Ninth embodiment)
FIG. 11 is a side view of a light emitting module 200 according to the ninth embodiment. The configuration of the vehicle headlamp 10 is the same as that of the first embodiment except that the light emitting module 200 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The light emitting module 200 is the same as the light emitting module 140 according to the sixth embodiment, except that the light emitting surface 82a of the semiconductor light emitting element 82 and the incident surface 84a of the light wavelength conversion member 84 are bonded to each other by direct bonding instead of an adhesive. Configured. Further, the direct bonding method, the materials of the semiconductor light emitting element 82 and the light wavelength conversion member 84 are the same as those in the seventh embodiment.

  Also by this, the light emitted from the semiconductor light emitting element 82 can be incident on the light wavelength conversion member 84 without using an adhesive. For this reason, compared with the case where an adhesive bond layer is provided between the semiconductor light-emitting element 82 and the light wavelength conversion member 84, light can be incident on the light wavelength conversion member 84 with higher efficiency.

(Tenth embodiment)
FIG. 12 is a side view of the light emitting module 220 according to the tenth embodiment. The configuration of the vehicular headlamp 10 is the same as that of the first embodiment except that a light emitting module 220 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The light emitting module 220 includes a semiconductor light emitting element 222 and an optical wavelength conversion member 224. The semiconductor light emitting device 222 includes a semiconductor layer 228 and a crystal growth substrate 230. Each of the semiconductor layer 228 and the crystal growth substrate 230 is configured similarly to the semiconductor layer 54 and the crystal growth substrate 56 according to the first embodiment. Therefore, the semiconductor light emitting element 222 is also provided so as to emit mainly blue light.

  The light wavelength conversion member 224 is disposed such that the incident surface 224a faces the light emitting surface 222a of the semiconductor light emitting element 222, and the light incident from the incident surface 224a is wavelength-converted and emitted. The material of the light wavelength conversion member 224 is also the same as that of the light wavelength conversion member 50 according to the first embodiment. For this reason, the light wavelength conversion member 224 is also provided so as to convert the wavelength of blue light and emit yellow light. Therefore, the semiconductor light emitting element 222 also emits white light that is a combined light of blue light and yellow light.

  As in the first embodiment, a so-called flip chip type light emitting module 220 is employed. However, it is of course not limited to this, and for example, a vertical chip type or a so-called face-up type may be employed.

In the tenth embodiment, the incident surface 224a of the light wavelength conversion member 224 is provided with irregularities. Further, a buffer layer 226 is formed between the incident surface 224a and the light emitting surface 222a so that the semiconductor light emitting element 222 and the light wavelength conversion member 224 are fixed to each other using direct bonding. By providing the buffer layer 226, direct bonding can be more easily performed. The material forming the buffer layer 226 may be YAG or SiO ₂ .

  The buffer layer 226 is formed as a thin film on the light emitting surface 222a of the semiconductor light emitting element 222 by sputtering. Instead of sputtering, vapor deposition, MOCVD (Metal Organic Chemical Vapor Deposition), or MBE (Molecular Beam Epitaxy) may be used. The buffer layer 226 has a light-transmitting property that transmits at least part of the light emitted from the semiconductor light emitting element 222.

Next, the buffer layer 226 and the light emitting surface 222a of the semiconductor light emitting element 222 are bonded together by direct bonding. As a result of experiments conducted by the inventors, it was confirmed that both surface activated bonding and plasma bonding can be directly bonded. Note that it has been confirmed that, even if the material forming the buffer layer 226 is YAG or SiO ₂ , both can be fixed by these bonding methods. Therefore, also by such an aspect, the semiconductor light emitting element 222 and the light wavelength conversion member 224 can be fixed to each other using direct bonding.

  The buffer layer 226 is formed on the convex portion so that an opening penetrating the concave portion is formed. As a result, the buffer layer 226 is formed on the convex portion to be directly bonded, and an opening that penetrates the concave portion is provided, so that a region through which light can pass without passing through the buffer layer 226 can be secured. Depending on the material of the buffer layer 226, the light transmittance may be lower than that of the light wavelength conversion member 224 or the like. By providing the opening in the buffer layer 226 in this manner, it is possible to suppress a decrease in light extraction efficiency due to the buffer layer 226 itself.

(Eleventh embodiment)
FIG. 13 is a side view of the light emitting module 240 according to the eleventh embodiment. The configuration of the vehicular headlamp 10 is the same as that of the first embodiment except that a light emitting module 240 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The light emitting module 240 includes a semiconductor light emitting element 242 and an optical wavelength conversion member 244. The semiconductor light emitting device 242 includes a semiconductor layer 248 and a crystal growth substrate 250. Each of the semiconductor layer 248 and the crystal growth substrate 250 is configured similarly to the semiconductor layer 54 and the crystal growth substrate 56 according to the first embodiment. For this reason, the semiconductor light emitting element 242 is also provided so as to emit mainly blue light.

  The light wavelength conversion member 244 is disposed so that the incident surface 244a faces the light emitting surface 242a of the semiconductor light emitting element 242, and the light incident from the incident surface 244a is wavelength-converted and emitted. The material of the light wavelength conversion member 244 is also the same as that of the light wavelength conversion member 50 according to the first embodiment. Therefore, the light wavelength conversion member 244 is also provided so as to convert the wavelength of blue light and emit yellow light. Therefore, the semiconductor light emitting element 242 also emits white light that is a combined light of blue light and yellow light.

  As in the first embodiment, a so-called flip chip type light emitting module 240 is employed. However, it is of course not limited to this, and for example, a vertical chip type or a so-called face-up type may be employed.

  In the eleventh embodiment, the light emitting surface 242 a of the semiconductor light emitting element 242, that is, the outer surface of the crystal growth substrate 250 is provided with irregularities. Note that when the substrate for crystal growth is removed, unevenness may be provided on the outer surface of the semiconductor layer 248, that is, the epi layer. Further, a buffer layer 246 is formed on the light emitting surface 242a in order to fix the semiconductor light emitting element 242 and the light wavelength conversion member 244 to each other using direct bonding. By providing the buffer layer 246, direct bonding can be more easily performed. The material of the buffer layer 246, the method of forming the light emitting surface 242a, and the method of directly bonding the light wavelength conversion member 244 to the incident surface 244a are the same as those of the buffer layer 226 according to the tenth embodiment.

  The buffer layer 246 is formed on the convex portion so that an opening penetrating the concave portion is formed. Accordingly, even when the buffer layer 246 is formed on the light emitting surface 242a, it is possible to suppress a decrease in light extraction efficiency due to the buffer layer 246 itself.

  Note that after the buffer layer 246 is formed on the entire surface of the light emitting surface 242a of the semiconductor light emitting element 242, the light emitting surface 242a is processed from above the buffer layer 246 so that a recess is formed. Accordingly, the buffer layer 246 can be easily formed on the convex portion of the light emitting surface 242a so that an opening penetrating the concave portion of the light emitting surface 242a is formed.

(Twelfth embodiment)
FIG. 14 is a side view of the light emitting module 260 according to the twelfth embodiment. The configuration of the vehicular headlamp 10 is the same as that of the first embodiment except that a light emitting module 260 is provided instead of the light emitting module 40. Hereinafter, the same parts as those in the above-described embodiment are denoted by the same reference numerals and description thereof is omitted.

  The light emitting module 260 includes a semiconductor light emitting element 262 and an optical wavelength conversion member 264. The semiconductor light emitting device 262 includes a semiconductor layer 268 and a crystal growth substrate 270. Each of the semiconductor layer 268 and the crystal growth substrate 270 is configured similarly to the semiconductor layer 54 and the crystal growth substrate 56 according to the first embodiment. For this reason, the semiconductor light emitting element 262 is also provided so as to emit mainly blue light.

  The light wavelength conversion member 264 is disposed so that the incident surface 264a faces the light emitting surface 262a of the semiconductor light emitting element 262, and the light incident from the incident surface 264a is wavelength-converted and emitted. The material of the light wavelength conversion member 264 is also the same as that of the light wavelength conversion member 50 according to the first embodiment. For this reason, the light wavelength conversion member 264 is also provided to emit blue light by converting the wavelength of blue light. Therefore, the semiconductor light emitting element 262 also emits white light that is a combined light of blue light and yellow light.

  The light emitting module 260 is a so-called flip chip type as in the first embodiment. However, it is of course not limited to this, and for example, a vertical chip type or a so-called face-up type may be employed.

  In the twelfth embodiment, the light emitting surface 262a of the semiconductor light emitting element 262, that is, the outer surface of the crystal growth substrate 270 is provided with irregularities. Note that when the substrate for crystal growth is removed, unevenness may be provided on the outer surface of the semiconductor layer 268, that is, the epi layer.

  Further, a buffer layer 266 is formed on the light emitting surface 262a so that the semiconductor light emitting element 262 and the light wavelength conversion member 264 are fixed to each other using direct bonding. The buffer layer 266 is directly bonded to the incident surface 264a. The buffer layer 266 may be formed on the incident surface 264a of the light wavelength conversion member 264 and directly bonded to the light emitting surface 262a. By providing the buffer layer 266, direct bonding can be performed more easily. The material, formation method, and direct bonding method of the buffer layer 266 are the same as those of the buffer layer 226 according to the tenth embodiment.

  The semiconductor light emitting element 262 and the light wavelength conversion member 264 are formed with concavities and convexities so that the tips of the convex portions provided in each face each other. The buffer layer 266 is formed on the convex portion so that an opening penetrating the concave portion is formed. Accordingly, the recesses of both the semiconductor light emitting element 262 and the light wavelength conversion member 264 communicate with each other. For this reason, also by such an aspect, the light extraction efficiency fall by the buffer layer 266 itself can be suppressed.

  Note that after the buffer layer 266 is formed on the entire surface of the light emitting surface 262a of the semiconductor light emitting element 262, the light emitting surface 262a is processed from above the buffer layer 266 so that a recess is formed. Thus, the buffer layer 266 can be easily formed on the convex portion of the light emitting surface 262a so that an opening penetrating the concave portion of the light emitting surface 262a is formed.

  The present invention is not limited to the above-described embodiments, and an appropriate combination of the elements of each embodiment is also effective as an embodiment of the present invention. Various modifications such as design changes can be added to each embodiment based on the knowledge of those skilled in the art, and embodiments to which such modifications are added can also be included in the scope of the present invention. Here are some examples.

  In a modification, a semiconductor light emitting element that mainly emits ultraviolet light is used. The light wavelength conversion member is formed by laminating a plurality of light wavelength conversion layers that convert ultraviolet light into light of different colors. For example, a light wavelength conversion layer that converts ultraviolet light into blue light and a light wavelength conversion layer that converts ultraviolet light into yellow light may be laminated. Alternatively, a light wavelength conversion layer that converts ultraviolet light into blue light, a light wavelength conversion layer that converts ultraviolet light into green light, and a light wavelength conversion layer that converts ultraviolet light into red light may be laminated. Good. Thus, the light emitting module which emits white light can also be obtained by configuring the semiconductor light emitting element and the light wavelength conversion member.

  The light wavelength conversion member may include a plurality of types of phosphors that convert ultraviolet light into light of different colors. For example, a phosphor that converts ultraviolet light into blue light and a phosphor that converts ultraviolet light into yellow light may be included in the light wavelength conversion member. Alternatively, a phosphor that converts ultraviolet light into blue light, a phosphor that converts ultraviolet light into green light, and a phosphor that converts ultraviolet light into red light may be included in the light wavelength conversion member. Thus, the light emitting module which emits white light can also be obtained by configuring the semiconductor light emitting element and the light wavelength conversion member.

  40 light emitting module, 48a light emitting surface, 50 light wavelength converting member, 50a incident surface, 60 light emitting module, 62a light emitting surface, 64 light wavelength converting member, 64a light incident surface, 80 light emitting module, 82a light emitting surface, 84 light wavelength converting member, 84a Incident surface.

Claims (4)

A light emitting element;
A plate-shaped light wavelength conversion member that is arranged so that an incident surface faces the light emitting surface of the light emitting element, and that converts the wavelength of light incident from the incident surface and emits the light;
With
An unevenness is provided on the light emitting surface of the light emitting element or the incident surface of the light wavelength conversion member.   The light emitting module according to claim 1, wherein the light emitting surface of the light emitting element and the incident surface of the light wavelength conversion member are bonded to each other by direct bonding. A buffer layer formed on the light emitting surface of the light emitting device or the incident surface of the light wavelength converting member to fix the light emitting device and the light wavelength converting member to each other using direct bonding;
The light emitting module according to claim 1, wherein the buffer layer is formed on the convex portion so that an opening penetrating the concave portion is formed. A light emitting element;
A plate-shaped light wavelength conversion member that is arranged so that an incident surface faces the light emitting surface of the light emitting element, and that converts the wavelength of light incident from the incident surface and emits the light;
A photonic crystal interposed between a light emitting surface of the light emitting element and an incident surface of the light wavelength conversion member;
A light emitting module comprising:

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