Patent Publication Number: US-11390047-B2

Title: Optical component, method of manufacturing same, and light emitting device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 16/596,251, filed on Oct. 8, 2019, which claims priority to Japanese Patent Application No. 2018-191403, filed on Oct. 10, 2018, the disclosures of which are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     The present disclosure relates to an optical component, a method of manufacturing the optical component, and a light emitting device including the optical component. 
     A method has been known in which glass is molded into a predetermined shape with a mold, and a plurality of pieces of glass identical in shape are divided from one another to manufacture a plurality of glass components identical in shape (for example Japanese Patent Publication No. 2011-178576). A glass component manufactured in this way may be provided with a reflective film on its surface, then the glass component can be used as an optical component having reflectivity. 
     SUMMARY 
     When a shape is formed with a mold using the method described in the Japanese Patent Publication No. 2011-178576, there are cases in which the component is formed with a shape insufficient to a desired degree of accuracy. This may affect the mounting accuracy at the time of mounting an optical component in manufacturing of a light emitting device. 
     According to one embodiment, a method of manufacturing an optical component includes: providing a base, the base including a projection which has an upper surface, a plurality of lateral surfaces, a first light control region positioned on at least one of the lateral surfaces, a first non-light-control region continued from the first light control region, and a second non-light-control region on a side closer to the upper surface than the first light control region, the first light control region being present between the first non-light-control region and the second non-light-control region in a direction perpendicularly extending from the upper surface of the projection; forming a lower surface of the optical component by processing a lower surface of the base such that the first non-light-control region in the base remains; and forming an upper surface of the optical component by processing an upper surface of the base to remove the second non-light-control region before or after forming the lower surface of the optical component. The optical component manufactured by the method has the first light control region and the first non-light-control region on the at least one lateral surface. 
     According to another embodiment, an optical component having an upper surface, a lower surface, a plurality of lateral surfaces, and a light reflecting surface provided on at least one of the lateral surfaces, comprising: a first light control region provided on the light reflecting surface, and a first non-light-control region continuous with the first light control region between the first light control region and the lower surface in a direction extending perpendicularly from the upper surface of the projection. The optical component has an angular boundary between the upper surface and the light reflecting surface. 
     According to another embodiment, a light emitting device includes: a base member having a first upper surface; a semiconductor laser element disposed on the first upper surface; and the light reflecting member described above, which is disposed on the first upper surface and configured to reflect light from the semiconductor laser element. 
     According to the optical component and the method of manufacturing the optical component of the present disclosure, it is possible to provide an optical component with a high degree of accuracy. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an optical component according to an embodiment. 
         FIG. 2  is a perspective diagram showing a state of optical component in one of the steps in the manufacturing method thereof. 
         FIG. 3  is a sectional view taken along line in  FIG. 2 . 
         FIG. 4  is a schematic diagram for illustrating a shape of a base formed to match a mold. 
         FIG. 5  is a schematic diagram for illustrating a shape of a base molded with a mold. 
         FIG. 6  is a schematic sectional view showing a state of the optical component in one of the steps in the manufacturing method thereof. 
         FIG. 7  is a schematic sectional view showing a state of the optical component in one of the steps on the manufacturing method thereof. 
         FIG. 8  is a schematic sectional view showing a state of the optical component in one of the steps in the manufacturing method thereof. 
         FIG. 9  is a perspective diagram showing a state of the optical component in one of the steps according to the manufacturing method thereof. 
         FIG. 10  is a perspective diagram showing a state of the optical component in one of the steps according to the manufacturing method thereof. 
         FIG. 11  is a perspective view showing one example of a light emitting device in which the optical component according to the embodiment is mounted. 
         FIG. 12  is a perspective view for illustrating an internal arrangement in the light emitting device in which the optical component according to the embodiment is mounted. 
         FIG. 13  is a top view for illustrating an arrangement of the optical component in the light emitting device in which the optical component according to the embodiment is mounted. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure will be described below with reference to the drawings. It is to be noted that the embodiments shown below are intended to embody the technical ideas of the present invention, and are not intended to limit the present invention. The same names and the same reference numerals represent the same or substantially the same components, and repeated descriptions of such components will be omitted. The sizes and positional relations of members shown in the drawings may be exaggerated for clarification of explanation. 
       FIG. 1  is a schematic view of an optical component  100  according to the embodiment of the present disclosure. The optical component  100  has an upper surface  120 , a lower surface  130  and lateral surfaces  140 , and a light reflecting surface  110  is formed at some of the lateral surfaces  140 . The upper surface  120  and the lower surface  130  include flat surfaces parallel to each other. The upper surface  120  and the lower surface  130  are not required to be parallel to each other. Further, the upper surface  130  and the lower surface  120  are rectangular flat surfaces, the lower surface  130  has an area larger than that of the upper surface  120 . In a top view, the boundary between the upper surface  120  and the light reflecting surface  110  is present within a region surrounded by the outer periphery of the lower surface, and positioned between a side of the lower surface  130  crossing the light reflecting surface  110 , and a side on the opposite side. The term “rectangular” in the present specification may include a square. 
     Except for the light reflecting surface  110 , the lateral surfaces  140  include a plurality of flat surfaces meeting the upper surface  120  and the lower surface  130 . Among these lateral surfaces  140 , two lateral surfaces  140  meeting the light reflecting surface  110  include flat surfaces parallel to each other. Further, the two lateral surfaces  140  include flat surfaces perpendicular to the lower surface  130  and the upper surface  120 . The two lateral surfaces are not required to be parallel to each other. The two lateral surfaces are not required to be perpendicular to the lower surface  130  or the upper surface  120 . 
     A lateral surface  140  on a side opposite to the light reflecting surface  110  is inclined as extending from the upper surface  120  to the lower surface  130 . This lateral surface may be perpendicular to the upper or lower surfaces. This lateral surface  140  is inclined at a draft angle which facilitates release from a mold. The angle formed by this lateral surface  140  with the lower surface  130  is preferably 82 degrees to 90 degrees, more preferably 85 degrees to 87 degrees. 
     The light reflecting surface  110  has a first light control region  111  and a second light control region  112 . Further, the light reflecting surface  110  has a first non-light-control region  113 . In the present specification, the light control region is a region designed to intentionally control the advancing direction of light so that light radiated from a semiconductor laser element as described later is reflected at the region to advance toward a specific location. The non-light-control region is a region which is not intended to intentionally control the advancing direction of light regardless of whether or not the region has light-reflectivity and regardless of whether or not the region is irradiated with light. 
     The optical component  100  has two flat surfaces different in angle with respect to the lower surface  130  at the light reflecting surface  110 , and these flat surfaces correspond to the first light control region  111  and the second light control region  112 . Of these flat surfaces, a flat surface on a side closer to the lower surface  130  is the first light control region  111 , and a flat surface on a side closer to the upper surface  120  is the second light control region  112 . The first light control region  111  or the second light control region  112  is not required to be the flat surface, but may be the curved surface. In the present embodiment, the angle with respect to the lower surface  130  is an angle formed by the lower surface  130  with a straight line connecting both ends of the region or a flat surface connecting the four corners of the region. 
     Further, the first non-light-control region  113  continued from the first light control region  111  is present between the lower surface  130  and the first light control region  111 . The first non-light-control region  113  is a curved surface, which is not intentionally formed into curved surface but is a region formed as a result of forming the first light control region  111  in a process of manufacturing the optical component  100 . As described in detail later, a second non-light-control region  114  is also generated as a result of forming the second light control region  112  in the process of manufacturing the optical component  100 , but the second non-light-control region  114  is removed. 
     In the optical component  100 , the upper surface  120  and the second light control region  112  meet each other. Further, the second light control region  112  meets the first light control region  111  on a side opposite to a side on which the second light control region  112  meets the upper surface  120 . That is, the first light control region  111  and the second light control region  112  are connected to each other. Rather than being connected, another region (i.e. an intermediate region) may be provided between these regions. For example, a third light control region may be further present as an intermediate region. The light reflecting surface  110  may have three or more light control regions. The light reflecting surface  110  may have a structure in which only one light control region is present. For example, only the first light control region  111  may be present as a light control region. 
     The optical component  100  is prepared using borosilicate glass as a principal material. For example, an outer shape of the optical component  100  as shown in  FIG. 1  is formed by molding glass, and a reflecting film is provided in a region to be the light reflecting surface  110 , thereby providing the optical component  100 . The optical component  100  may have a metal film provided on the lower surface. As the principal material of the optical component  100 , for example, optical glass containing additives or the like can be used besides borosilicate glass. 
     A method of manufacturing the optical component  100  will now be described with reference to  FIGS. 2 to 10 . 
       FIG. 2  is a perspective diagram showing a state in which a base  200  is molded using a mold in manufacturing of the optical component  100 . The base  200  is formed using a principal material for the optical component  100  as described above. As shown in  FIG. 2 , the base  200  has a component region  210  as a region which is processed to manufacture the optical component  100 , and an outer peripheral region  220  surrounding the component region  210 . 
     In the component region  210 , a projection  211  having a shape corresponding to a lateral surface on a side on which the light reflecting surface  110  of the optical component  100  is formed and a lateral surface on the opposite side is provided. The projection  211  is provided in a shape extending to the outer peripheral region  220  from one lateral surface of the base  200  toward a lateral surface on the opposite side. Further, a plurality of projections  211  is arranged side by side at equal intervals, and adjacent projections  211  are arranged parallel to each other so as to ensure constant intervals. The projections are not required to be arranged at equal intervals, and may be arranged at predetermined intervals.  FIG. 3  is a diagram for illustrating the shape of a plurality of projections  211  provided in the component region  210 , and is a partial sectional view taken along line in  FIG. 2 . 
     In the projection  211 , a lateral surface on a side corresponding to the light reflecting surface  110  has the first light control region  111 , the second light control region  112 , the first non-light-control region  113  and the second non-light-control region  114 . Further, the first non-light-control region  113  continued from the first light control region  111  is formed, and the first light control region  111  is present between the first non-light-control region  113  and the second light control region  112  in a direction perpendicularly extending from the upper surface of the projection. Similarly, the second non-light-control region  114  continued from the second light control region  112  is formed, and the second light control region  112  is present between the second non-light-control region  114  and the first light control region  111 . 
     Therefore, the regions are formed such that the second non-light-control region  114 , the second light control region  112 , the first light control region  111  and the first non-light-control region  113  are arranged in this order from the side close to the upper surface. The first non-light-control region  113  further reaches the adjacent projection  211 . That is, at this time, a plurality of projections  211  is connected in the component region  210  regardless of connection with the outer peripheral region  220 . The projections may be connected to each other via the outer peripheral region  220 . At this time, the projections may be connected to each other only via the outer peripheral region  220 . 
     An intermediate region may be present between the first light control region  111  and the second light control region  112  as described above, but there is no intermediate region between the first light control region  111  and the first non-light-control region  113 . Also, there is no intermediate region between the second light control region  112  and the second non-light-control region  114 . This is because the first non-light-control region  113  is provided as a result of formation of the first light control region  111 , and the second non-light-control region  114  is provided as a result of formation of the second light control region  112 . This point will be described in further detail with reference to  FIGS. 4 and 5 . 
       FIG. 4  is a diagram showing the shape of the projections  211  formed using the mold assuming the projection  211  is exactly fitted in the mold.  FIG. 5  is a diagram showing a comparison of the shape of the mold with the shape of the projection  211  where the projection  211  is molded using the mold. In  FIG. 5 , the broken line indicates the shape of the mold in  FIG. 4 , and the solid line indicates the shape of the projection  211  molded. 
     As shown in  FIG. 4 , if the projection  211  is formed by being exactly fitted in the mold, a second light control region  213  meets an uppermost surface  216 , and meets a first light control region  212  at a side on the opposite side. At a side on a side opposite to the side meeting the second light control region  213 , the first light control region  212  meets an adjustment surface  214  for adjusting the height from the lower surface of the optical component  100  to the first light control region  212 . At a side on a side opposite to the side meeting the first light control region  212 , the adjustment surface  214  meets a connection surface  215  which is a flat surface connecting adjacent projections  211 . At a side on a side opposite to the side meeting the adjustment surface  214 , the connection surface  215  meets a lateral surface  217  on a side opposite to the surface of the neighbor projection  211  on which the light reflecting surface is formed. The connection surface  215  is provided under the uppermost surface  216  of the projection  211  and above the lower surface of the base  200 . 
     Further, the boundary between the first light control region  212  and the second light control region  213 , the boundary between the first light control region  212  and the adjustment surface  214 , the boundary between the adjustment surface  214  and the connection surface  215 , the boundary between the connection surface  215  and the lateral surface  217  of the neighbor projection  211 , the boundary between the second light control region  213  and the uppermost surface  216 , and the boundary between the uppermost surface  216  and the lateral surface  217  of the projection  211  are all angular. In the present embodiment, the phrase “the boundary is angular” means that the boundary has an angle and no roundness. However, the shape of the projection  211  is formed by being exactly fitted in the mold, the boundary is angular within the bounds of following the shape of the mold. 
     As shown in  FIG. 5 , a shape of the projection  211  actually molded from the mold is not the same as the shape of the projection  211  exactly fitted in the mold. Comparison between these shapes shows that the actually molded shape of the projection  211  has a roundness at and near the boundary. When the shape of the mold has such roundness, the roundness of the actually formed projection is larger than the roundness of the mold. 
     Therefore, with regard to a portion formed in conformity to the mold, the first light control region  111 , the second light control region  112 , an adjustment surface  115 , a connection surface  116 , an uppermost surface  117  and a lateral surface  118  on a side opposite to a surface at which a light reflecting surface is to be formed are respectively smaller in size than the first light control region  212 , the second light control region  213 , the adjustment surface  214 , the connection surface  215 , the uppermost surface  216  and the lateral surface  217 . 
     This is attributed to such a nature that it is difficult to correctly transfer fine shapes of the mold due to the viscosity of glass, and the like. Consequently, the first non-light-control region  113  is formed between the first light control region  111  and the adjustment surface  115  in a region corresponding to the boundary between the first light control region  212  and the adjustment surface  214  and the vicinity of the boundary. Similarly, the second non-light-control region  114  is formed between the second light control region  112  and the uppermost surface  117  in a region corresponding to the boundary between the second light control region  213  and the uppermost surface  216  and the vicinity of the boundary. 
     This roundness becomes larger as the angle formed by two meeting surfaces decreases. An angle less than 180 degrees is more likely to be rounded. Therefore, a roundness generated at the boundary between the first light control region  212  and the second light control region  213  is smaller than a roundness generated at the boundary between the first light control region  212  and the adjustment surface  214  and/or at the boundary between the second light control region  213  and the uppermost surface  216 . Hence, a roundness generated between the first light control region  111  and the second light control region  112  is not shown in the drawings. 
     This fact does not indicate that a roundness is not generated between the first light control region  111  and the second light control region  112 . The present disclosure disclosed on the basis of the optical component  100  according to the embodiment is applicable regardless of whether or not the optical component  100  is absolutely required to have a roundness between the first light control region  111  and the second light control region  112 . 
     The rounded shape in the first non-light-control region  113  is smoothly continued from the first light control region  111 , and also smoothly continued from the adjustment surface  115 . The rounded shape in the second non-light-control region  114  is smoothly continued from the second light control region  112 , and also smoothly continued from the uppermost surface  117  of the projection  211 . The term “smoothly continued” refers to a state of being free from an angle, as opposed to an angular state. 
     Therefore, when the first light control region  111  and the second light control region  112  are to be provided in a desired size, a mold is designed on the premise that a non-light-control region is formed. The roundness is generated under the influence of the viscosity of glass, or the like. Thus, depending on the degree of the influence, the first non-light-control region  113  and the second non-light-control region  114  formed on a projection  211  molded in a base  200  is not necessarily identical in shape to the first non-light-control region  113  and the second non-light-control region  114  formed on another projection  211  molded in the base  200 . 
     When only the first light control region  111  is present as a light control region on the light reflecting surface  110 , the second non-light-control region  114  is smoothly continued from the first light control region  111 , and smoothly continued from the uppermost surface  117 . That is, from the first light control region  111 , the first non-light-control region  113  and the second non-light-control region  114  are respectively smoothly continued to the adjustment surface side and the uppermost surface side. 
     After projection  211  of the base  200  is formed with the mold in this way, a reflecting film is deposited by a method such as vapor deposition or sputtering on a lateral surface on a side on which the light reflecting surface  110  of the optical component  100  is to be formed. 
     Specifically, the light reflecting surface  110  can be formed by depositing a multilayer film of Ta 2 O 5  and SiO 2 , a multilayer film of TiO 2  and SiO 2 , or the like. In addition, a metallic material having a high reflectivity, such as silver may be used as a reflecting film to form the light reflecting surface  110 . 
     In the base  200 , a plurality of projections  211  is arranged such that the first light control regions  111  of the light reflecting surfaces  110  of the respective projections  211  are parallel to one another, and similarly, the second light control regions  112  are parallel to one another. A plurality of projections  211  is formed so as to face in the same direction as described above, thus thickness unevenness is less likely to occur in deposition of the reflecting film. Therefore, among a plurality of optical components  100  manufactured from the same base  200 , the uniformity of the light reflecting surface  110  is improved, and a high reflectivity can be obtained at the entire light reflecting surface  110 . 
     After the light reflecting surface  110  is formed, a sheet material  900  is bonded to the uppermost surface  117  of the projection  211 , and the lower surface of the base  200  is ground. For the sheet material  900 , for example, an ultraviolet ray-curable dicing tape can be used. Besides the method using a sheet material, for example, an adhesive such as a wax can be used to fix the projections  211 . 
       FIG. 6  shows a state of the projections  211  after the lower surface of the base  200  is ground. As shown in  FIG. 6 , in this step, the connection surface  116  connecting a plurality of projections  211  in the component region  210  is removed. The component region  210  and the outer peripheral region  220  are connected to each other in the base  200 , thus arrangement of a plurality of projections  211  is maintained. 
     The lower surface  130  of the optical component  100  is formed by the grinding. How much thickness is cut in this step depends on how much height is secured between the lower surface  130  and the first light control region  111  in the optical component  100 . In the present embodiment, grinding is performed such that at least a part of first non-light-control regions  113  remain. When it is not necessary to secure the height from the lower surface  130  to the first light control region  111 , grinding can be performed such that the first non-light-control region  113  does not remain. In contrary, grinding may be performed such that part of the adjustment surface  115  remains in addition to the first non-light-control region  113 . 
     The method for forming the lower surface  130  of the optical component  100  is not required to be grinding. A method other than grinding can be used as long as processing for forming the lower surface  130  of the optical component  100  can be performed. For example, using a method such as etching by which a surface is dissolved with hydrogen fluoride or the like, or polishing such as sand blasting by which sand is sprayed to grind a surface, processing may be performed by which part of the base  200  is removed from the lower surface side until reaching the lower surface  130  of the optical component  100 . 
     After the lower surface  130  of the optical component  100  is formed, the sheet material  900  is bonded to the lower surface  130  of the optical component  100 , and the uppermost surface  117  of the projection  211  is ground. In the present embodiment, for the sheet material  900 , for example, an ultraviolet ray-curable dicing tape can be used. Further, instead of the sheet material, an adhesive such as a wax can be used. 
     The sheet material  900  bonded to the uppermost surface  117  is removed before the uppermost surface  117  of the projection  211  is ground.  FIG. 7  shows a state in which the uppermost surface  117  of the projection  211  is ground. How much thickness is cut from the uppermost surface  117  is determined by measuring the thickness of the projection  211 . 
     The thicknesses of individual projections  211  are measured because there is a variance in the thickness. From the results of the measurements, the thickness of the component region  210  to be ground is determined. For example, an average of grinding thicknesses determined from individual projections  211  can be determined as a grinding thickness for a plurality of projections  211 . Further, the grinding thickness for individual projections  211  can be determined from the measurement results of individual projections  211 . 
     By the grinding, the second non-light-control region  114  is removed. Grinding is performed such that the second light control region  112  remains. Consequently, the upper surface  120  of the optical component  100  is formed, and the upper surface  120  and the second light control region  112  meet each other such that the boundary therebetween is angular. At least as compared to a state in which the first light control region  111  and the first non-light-control region  113  are smoothly continued, the boundary between the upper surface  120  and the second light control region  112  is angular. While the thickness to be ground varies depending on the size and the thickness of the projection  211 , the size of the second non-light-control region  114 , and the like, for example, a thickness of 100 μm to 2000 μm is ground. 
     Further, by the step of forming the upper surface  120  of the optical component  100 , and the step of forming the lower surface  130  of the optical component  100 , the light reflecting surface  110  of the optical component  100 , and the lateral surface  140  on a side opposite to the light reflecting surface  110  are formed. 
     Even when a reflecting film is partially deposited on the uppermost surface  117  of the projection  211  in the above-described step of depositing a reflecting film, this grinding step produces a state in which there is no reflecting film formed on and the material of the base  200  is exposed at the upper surface  120  of the optical component  100 . Therefore, by accurately performing grinding such that the surface roughness of the ground surface decreases, the lower surface  130  can be seen through the upper surface  120  of an optical component in the case in which the base  200  has high transparency. Thus, it is preferable to perform grinding such that the surface has an arithmetic average roughness Ra of 0.1 μm at most. 
     In the present embodiment, processing for forming the upper surface  120  of the optical component  100  may be performed using a method other than the grinding such as etching. These methods may be combined. For example, a method may be employed in which the upper surface  120  and the lower surface  130  of the optical component  100  are formed by removing the surface to a certain degree by sand blasting, and performing grinding for reducing the surface roughness. 
     The step of grinding the lower surface of the base  200  may be carried out after the step of grinding the uppermost surface  117  of the projection  211 . In this case, a sheet material is bonded to the lower surface of the base  200 , and the uppermost surface  117  of the projection  211  is ground to form the upper surface  120  of the optical component  100 , followed by bonding a sheet material to the upper surface of the optical component  100 , and grinding the lower surface of the base  200  to form the lower surface  130  of the optical component  100 . With regard to the order, the sheet material may be bonded first to a surface having a smaller degree of warpage with consideration for the degree of warpage of the base provided with the projection  211 . With this order, effect of the warpage caused by grinding can be reduced. Therefore, the lower surface of a base  200  having a large degree of warpage may be ground first. 
     After the upper surface of the optical component  100  is formed, a metal film  150  is provided on the lower surface  130  of the optical component  100 . The sheet material bonded to the lower surface  130  of the optical component  100  is removed.  FIG. 8  shows a state in which the metal film  150  is provided on the lower surface  130  of the optical component  100 .  FIG. 9  shows a state of the base  200  at the time when the metal film  150  is provided on the lower surface  130  of the optical component  100 . The metal film  150  can be formed by depositing a metal such as Au or AuSn by a method such as vapor deposition or sputtering while a region on which the metal film  150  is not intended to be provided is covered with a mask. 
     Subsequently, in a state in which a sheet material bonded to the lower surface  130  of the optical component  100 , the base  200  is cut to divide projections  211  from one another, so that individual optical components  100  are formed. For the sheet material, for example, an ultraviolet ray-curable dicing tape can be used.  FIG. 10  shows a state in which the base  200  is cut. Cut surfaces obtained by cutting form two lateral surfaces  140  of the optical component  100 , where the lateral surfaces  140  are each different from a lateral surface  140  forming the light reflecting surface  110 , and meet the lateral surface  140  forming the light reflecting surface  110 . When the base has high transparency, the metal film provided on the lower surface  130  is visible from the upper surface side of the optical component  100 , and therefore cutting can be performed while the position of the metal film is checked from the upper surface side. 
     The method for dividing the base into optical components  100  is not limited to cutting. A method other than cutting can be used as long as processing for forming two lateral surfaces  140  of the optical component  100  which meet the light reflecting surface  110  can be performed. For example, a method can also be used in which the base is scribed by a diamond scribing cutter or laser irradiation, and then cleaved by breaking. 
     In this way, a plurality of optical components  100  is manufactured from the base  200 . With this manufacturing method, a large number of optical components  100 , for example 10 or more optical components  100  can be manufactured from one base  200 . When manufacturing the same size of the optical components  100 , as the size of the base  200  increases, the size of the component region  210  increases. This can increase the number of optical components  100  manufactured from one base  200 . On the other hand, when the size of the component region  210  increases, there may be an effect such as reduction in the accuracy of the optical component  100  manufactured. For example, when the number of optical components  100  manufactured from one base  200  is 3000 or less, mass productivity can be improved while maintaining accuracy. However, it depends on the size of the optical components  100 . 
     Light Emitting Device  300   
     A light emitting device  300  in which the optical component  100  according to the embodiment is arranged will now be described with reference of  FIGS. 11 to 13 .  FIG. 11  is a perspective view of the light emitting device  300 .  FIG. 12  is a perspective view of the light emitting device  300 , where some of constituent elements are not shown and some of constituent elements are seen through for illustrating the arrangement of the optical component  100  in the light emitting device  300 . The seen-through constituent elements are indicated by broken lines, and the extension lines of these constituent elements are indicated by broken lines.  FIG. 13  is a top view of the light emitting device  300  shown in  FIG. 12 . The constituent elements not shown and the constituent elements seen through in  FIG. 12  are both not shown in  FIG. 13 . 
     The light emitting device  300  includes a base member  310 , a semiconductor laser element  320 , a light reflecting member  330  as the optical component  100  according to the embodiment, a lid  340 , a fluorescent portion  350 , a first light shielding portion  360 , a second light shielding portion  370 , a sub-mount  380 , a wire  381 , a thermistor  382 , and a Zener diode  383 . Further, two semiconductor laser elements  320 , and two light reflecting members  330  corresponding to the respective semiconductor laser elements  320  are present. 
     The base member  310  is provided with a recess depressed at a central portion thereof. The recess of the base member  310  has a first upper surface  311 , a second upper surface  312  positioned above the first upper surface  311 , and one or more step surfaces  313  positioned above the upper surface  311  and under the second upper surface  312 . That is, the recess has one or more step surfaces  313  provided stepwise from the first upper surface  311  in such a manner as to reach the second upper surface  312  at the tip of the step. The first upper surface  311  is surrounded by the second upper surface  312 . The first upper surface  311 , the second upper surface  312  and the upper surface in the step surfaces  313  are substantially parallel to the lower surface of the base member  310 . 
     The base member  310  has a plurality of wiring portions  314  provided in some regions of the first upper surface  311  and the second upper surface  312  of the recess formed of an insulating material. Providing the wiring portion  314  on surfaces other than the lower surface of the base member  310  can widen a region of the lower surface, which can be connected to a heat dissipation member such as a heat sink, thereby improving the effect of heat dissipation from the lower surface. 
     The recess of the base member  310  can be formed using a material containing a ceramic as a main component. Examples of the ceramic include aluminum oxide, aluminum nitride, silicon nitride and silicon carbide, and aluminum nitride is preferable from the viewpoint of heat dissipation. For the wiring portion  314 , a metallic material such as gold, silver, aluminum, palladium or tungsten can be used. The base member  310  may have a base portion forming the first upper surface  311 , and a frame portion, separately, the base member  310  being formed by providing the frame portion on the upper surface of the base portion. 
     Light radiated from the semiconductor laser element  320  has an elliptic far-field pattern (FFP) in which a length in a stacking direction of a plurality of semiconductor layers including an active layer is greater than a length in a direction perpendicular to the stacking direction on a surface parallel to a light emitting end surface of the semiconductor laser element  320 . The FFP refers to a shape and a light intensity distribution of radiated light at a sufficient distance from the light emitting end surface of the semiconductor laser element  320 . The FFP is utilized for, for example, measuring a light intensity distribution at a certain distance from the light emitting end surface using an angle with respect to an optical axis as a parameter, and showing a correlation between the light intensity and the angle as a graph to measure the properties of the semiconductor laser element  320 . 
     As the semiconductor laser element  320 , one having a peak emission wavelength within the range of 320 nm to 530 nm, typically within the range of 430 nm to 480 nm can be used. The semiconductor laser element  320  emits radiated light with relatively high energy. The semiconductor laser element  320  is preferably formed using a material containing, for example, a nitride semiconductor. Examples of the material including nitride semiconductor include those containing at least one of GaN, InGaN and AlGaN. 
     The lid  340  has a lower surface, an upper surface and lateral surfaces. Further, the lid  340  includes a light-transmissive inorganic material, and has, for example, a rectangular solid shape. The lid  340  may be formed using a material composed of sapphire which is relatively easily transmitting radiated light, has high physical strength and high heat conductivity. The lid  340  may be formed using a light-transmissive material containing quartz, silicon carbide, glass or the like. 
     The fluorescent portion  350  has a lower surface, an upper surface serving as a light extraction surface, and lateral surfaces. Further, the upper surface of the fluorescent portion  350  has a shape elongated in one direction, and the lower surface of the fluorescent portion  350  has a shape elongated in one direction. From the viewpoint of mass productivity, the upper surface and the lower surface of the fluorescent portion  350  each have a rectangular shape, but may have an elliptic shape. The fluorescent portion  350  has light-transmissivity, and contains a fluorescent material such as a YAG fluorescent material, a LAG fluorescent material or an a-sialon fluorescent material. In particular, it is preferable to use a YAG fluorescent material which has high heat resistance. 
     Further, the fluorescent portion  350  is composed of an inorganic material. Accordingly, as compared to a fluorescent portion containing an organic material, the fluorescent portion  350  is less affected by heat and light, thereby improving its reliability. As the fluorescent portion  350  composed of an inorganic material, a fluorescent material ceramic or a single crystal fluorescent material can be used. As the fluorescent material ceramic, a sintered body of fluorescent material particles and a binding agent serving as a binder can be used. In the case in which a fluorescent material ceramic of a YAG fluorescent material is used, aluminum oxide may be used as an additive material. A fluorescent material including an organic material may be used. 
     The first light shielding portion  360  has a lower surface, an upper surface, outer lateral surfaces and inner lateral surfaces. Further, a space surrounded by the inner lateral surface extends through the first light shielding portion from the upper surface to the lower surface. The first light shielding portion  360  can be formed using a ceramic containing aluminum oxide as a main component. Further, aluminum nitride or the like may be used other than aluminum oxide. 
     The second light shielding portion  370  can be formed of, for example, a resin containing light absorbing particles of carbon or the like. The sub-mount  380  has a lower surface, an upper surface and lateral surfaces, and has a rectangular solid shape. The sub-mount  380  can be formed using, for example, aluminum nitride or silicon carbide. The upper surface and the lower surface of the sub-mount  380  can be plated with copper to improve it heat dissipation. The wire  381  is metallic wiring, and is used for electrical connection. The thermistor  382  can be, for example, a ceramic. The Zener diode  383  can be, for example, a silicon diode. 
     The configuration of the light emitting device  300  will now be described. 
     In the light emitting device  300 , two semiconductor laser elements  320  are each disposed on the first upper surface  311  of the base member  310  with the sub-mount  380  interposed therebetween. Further, two light reflecting members  330  are arranged on the first upper surface  311  of the base member  310  to reflect light radiated from the respective semiconductor laser elements  320 . Further, the thermistor  382  and the Zener diode  383  are arranged on the first upper surface  311  of the base member  310 . A plurality of wires  381  is each bonded to the semiconductor laser element  320 , the thermistor  382  or the Zener diode  383  at one end, and bonded to the wiring portion  314  of the first upper surface  311  at the other end. 
     The semiconductor laser element  320  is disposed such that the light emitting surface of the semiconductor laser element is perpendicular to the first upper surface  311  of the base member  310 , and the longitudinal direction of the FFP having an elliptic shape is perpendicular to the first upper surface  311  of the base member  310 . This ensures that a surface of the semiconductor laser element  320 , which has a larger area, can be bonded to the upper surface of the sub-mount  380 , so that heat generated by the semiconductor laser element  320  is easily dissipated to the base member  310  through the sub-mount  380 . The term “perpendicular” encompasses an inclination allowing for a shift during manufacturing. Such inclination encompasses, for example, an inclination of about ±10 degrees. 
     Interposition of the sub-mount  380  can increase the distance (i.e., height) between the first upper surface  311  of the base member  310  and the light emitting point of the light emitting surface of the semiconductor laser element  320  by an amount equivalent to the thickness of the sub-mount  380 . Accordingly, the light reflecting member  330  can be efficiently irradiated with light emitted from the semiconductor laser element  320 . 
     Thus, with respect to the first upper surface  311 , the boundary between the first non-light-control region  113  and the first light control region  111  is positioned above the lower surface of the sub-mount  380 , and it is desirable that the height from the lower surface of the light reflecting member  330  to the boundary between the first non-light-control region  113  and the first light control region  111  be smaller than the thickness from the lower surface to the upper surface of the sub-mount  380 . That is, it is desirable that the boundary between the first non-light-control region  113  and the first light control region  111  be positioned above the lower surface and under the upper surface of the sub-mount  380 . 
     Further, the thickness from the lower surface to the upper surface of the sub-mount  380  is preferably smaller than the height from the lower surface to the upper surface of the light reflecting member  330 . Further, the thickness from the lower surface to the upper surface of the sub-mount  380  is more preferably equal to the height up to the boundary between the first light control region  111  and the second light control region  112 . 
     The sub-mount  380  is preferably a sub-mount having a thermal expansion coefficient between the thermal expansion coefficient of the base member  310  and the thermal expansion coefficient of the semiconductor laser element  320 . This can alleviate delamination of the semiconductor laser element  320  or the sub-mount  380 . When a material containing a nitride semiconductor is used for the semiconductor laser element  320 , it is preferable to use aluminum nitride or silicon carbide for the sub-mount  380 . 
     The light reflecting member  330  is disposed such that the light reflecting surface  110  is irradiated with light emitted from the semiconductor laser element  320 . Further, the semiconductor laser element  320  is closer to the first light control region  111  than to the second light control region  112  side. Of two light reflecting members  330 , a first light reflecting member  331  reflects a major part of light from a first semiconductor laser element  321 , and a second light reflecting member  332  reflects a major part of light from a second semiconductor laser element  322  of two semiconductor laser elements  320 . 
     In this specification, a major part of light from the semiconductor laser element  320  may be light having a light intensity equal to or greater than 1/e 2  of the peak intensity value. In the light emitting device  300 , a major part of the light may be preferably light having a light intensity equal to or greater than 5% of the peak intensity value. A major part of the light may be more preferably light having a light intensity equal to or greater than 1% of the peak intensity value. 
     That is, in the light emitting device  300 , the first light control region  111  and the second light control region  112  of the light reflecting member  330  are regions which are irradiated with at least a major part of light in light emitted from the semiconductor laser element  320 . Further, the first non-light-control region  113  is a region which is not irradiated with at least a major part of light in light emitted from the semiconductor laser element  320 . Therefore, the first non-light-control region  113  may be irradiated with light other than a major part of light. 
     An angle A formed by the lower surface of the light reflecting member  330  with the first light control region  111  is smaller than an angle B formed by the lower surface of the light reflecting member  330  with the second light control region  112 . For example, the angle A is larger than 15 degrees and smaller than 45 degrees, and the angle B is larger than 45 degrees and smaller than 75 degrees. 
     As shown in  FIG. 13 , the first semiconductor laser element  321  and the second semiconductor laser element  322  are arranged such that the light emitting end surfaces of the semiconductor laser elements are parallel to each other. Further, in a top view, a straight line perpendicular to the emitting end surface of the first semiconductor laser element  321  is neither perpendicular nor parallel to a straight line passing through the boundary between the first light control region  111  and the second light control region  112  of the first light reflecting member  331 . In other words, in a top view, the first semiconductor laser element  321  and the first light reflecting member  331  are inclined to each other. Similarly, the second semiconductor laser element  322  and the second light reflecting member  332  are inclined to each other. The arrangement relation of the first light reflecting member  331  to the first semiconductor laser element  321  is the same as the arrangement relation of the second light reflecting member  332  to the second semiconductor laser element  322 . 
     In a top view, an angle α is formed by a straight line perpendicular to the emitting end surface of the first semiconductor laser element  321  and a straight line passing through the boundary between the first light control region  111  and the second light control region  112  of the first light reflecting member  331 . The angle α which is on the first light control region  111  and first semiconductor laser element  321  side is preferably in the range of 30 degrees to 80 degrees. The same applies to the second semiconductor laser element  322  and the second light reflecting member  332 . When the angle α is within this range, excessive expansion of light reflected by the light reflecting member  330  can be alleviated. It is more effective to set the angle α within the range of 30 degrees to 40 degrees. 
     Further, the first light reflecting member  331  and the second light reflecting member  332  are arranged such that the boundary lines of the first light control region  111  and the second light control region  112  are parallel to each other. Such arrangement enables one fluorescent portion  350  is irradiated with light from two semiconductor laser elements  320 . The term, “parallel” includes an inclination equivalent to a shift during manufacturing, for example an inclination of about ±10 degrees. 
     The wires  381  and the thermistor  382  are bonded to a plurality of wiring portions  314  provided on the first upper surface  311  of the base member  310 . Parts of a plurality of wiring portions  314  on the first upper surface  311  are respectively electrically connected to parts of a plurality of wiring portions  314  on the second upper surface  312  through an electrically conductive member provided in the base member  310 . This enables the semiconductor laser elements  320  and the thermistors  382  to be electrically connected to the outside through a plurality of wiring portions  314  on the second upper surface  312  of the base member  310 . By providing the thermistor  382 , the temperature of the semiconductor laser element  320  can be measured, and a current passing through the semiconductor laser element  320  can be adjusted in response to a temperature change. 
     The lid  340  is disposed on the upper surface of the step surface  313  of the base member  310 . A metal film is formed on each of bonding regions in the lower surface of the lid  340  and the upper surface of the step surface  313  of the base member  310 , and the metal films are fixed together with solder. The lid  340  is bonded over the entire periphery of the upper surface of the step surface  313  of the base member  310  to form a hermetically sealed space. The semiconductor laser element  320  and the like are disposed in this space. Forming such a hermetically sealed space can alleviate collection of organic substances and the like on the light emitting surface of the semiconductor laser element  320 . As the base member  310 , one having no step surface  313  may be used, and in this case, the lid  340  is disposed on a surface corresponding to the second upper surface  312  of the base member  310 . 
     The fluorescent portion  350  is disposed on the upper surface of the lid  340 . Light emitted from the semiconductor laser element  320  is reflected by the light reflecting member  330 , and passes through the lid  340  to enter the fluorescent portion  350 . Light incident to the fluorescent portion  350  passes through the fluorescent portion  350  to exit the light emitting device  300 . Therefore, the fluorescent portion  350  is a light extraction surface of the light emitting device  300 . 
     On the lower surface of the fluorescent portion  350 , a major part of light emitted from the semiconductor laser element  320  is applied in a shape elongated in one direction. The fluorescent portion  350  is disposed such that the longitudinal-direction size of the irradiated region on the lower surface of the fluorescent portion  350  is within the longitudinal-direction size of the lower surface of the fluorescent portion  350 . For example, the fluorescent portion  350  is disposed such that the longitudinal direction of the fluorescent portion  350  is perpendicular to the boundary line between the first light control region  111  and the second light control region  112  in a top view. Therefore, the first light control region  111  and the second light control region  112  of the light reflecting member  330  allow a major part of light from the semiconductor laser element  320  to advance toward the light extraction surface in the light emitting device  300 . 
     Further, the center of the fluorescent portion  350  is positioned within a range surrounded by a straight line passing through each of the boundary lines between the upper surfaces  120  and the second light control regions  112  in two light reflecting members  330  and lateral surfaces which meet both the boundary lines and is closer to the fluorescent portion  350 , in a top view. The fluorescent portion  350  may have a fluorescent portion having a width-direction size smaller than the longitudinal-direction size of the irradiated region on the lower surface of the fluorescent portion  350 . Further, heat generated at the fluorescent portion  350  can be dissipated to the base member  310  through the lid  340 . 
     The first light shielding portion  360  is provided so as to surround the lateral side of the fluorescent portion  350 . That is, the first light shielding portion  360  is provided such that the fluorescent portion  350  is provided within a through-hole defined by the inner lateral surfaces of the first light shielding portion  360  as seen from the upper surface side of the fluorescent portion  350 . By surrounding the lateral surfaces of the fluorescent portion  350  by the first light shielding portion  360 , light is less likely to emit from parts other than the upper surface of the fluorescent portion  350 . 
     In the case in which the fluorescent portion  350  contains a YAG fluorescent material, it is preferable that a ceramic containing aluminum oxide as a main component is used for the first light shielding portion  360 . The fluorescent portion  350  may be directly joined to the first light shielding portion  360  by a sintering method. At that time, an opening is generated in a region close to the fluorescent portion  350  of the first light shielding portion  360 . Light from the fluorescent portion  350  is reflected at the interface between a particle of aluminum oxide or the like and the opening, so that the first light shielding portion  360  hardly transmits light. 
     The second light shielding portion  370  is provided so as to cover part of the upper surface of the lid  340  and the lateral surfaces of the lid  340 . This can alleviate leakage of emitted light and fluorescent light from the lateral side of the lid  340 . 
     Effects of the optical component  100  according to the embodiment in the light emitting device  300  will now be described. The optical effect of the second light reflecting member  332  on a major part of light from the second semiconductor laser element  322  is the same as the optical effect of the first light reflecting member  331  on a major part of light from the first semiconductor laser element  321 . Thus the optical effects of these members will be described on the basis of the first semiconductor laser element  321  and the first light reflecting member  331 . 
     The first light reflecting member  331  changes a relative light distribution before reflection and after reflection by the first light control region  111  and the second light control region  112  such that a major part of light emitted from the first semiconductor laser element  321  exits from the fluorescent portion  350  as more uniform light. 
     For example, the first light reflecting member  331  is formed such that light reflected on a region of the first light control region  111  at a side close to the second light control region  112  and light reflected on a region of the second light control region  112  at a side close to the first light control region  111  meet each other before reaching the lower surface of the fluorescent portion  350 , and both end portions of the irradiated region on the lower surface of the fluorescent portion  350  are irradiated with the light. 
     The first light reflecting member  331  is formed such that, for example, in the irradiated region on the lower surface of the fluorescent portion  350 , the light intensity at each of both end portions in the longitudinal direction is higher than the light intensity at the central portion positioned away from both ends by equal distances. 
     Further, the first light reflecting member  331  is formed such that, for example, in a major part of light applied to the first light reflecting member  331 , a part of light having a relatively low light intensity overlaps the other part of light on the lower surface of the fluorescent portion  350 , and a part of light having a relatively high light intensity does not overlaps the other part of light on the lower surface of the fluorescent portion  350 . 
     A method of mounting the optical component  100  according to the embodiment in the light emitting device  300  will now be described. 
     A plurality of optical components  100  divided from the base  200  with a sheet material bonded to the optical components  100  is aligned on the sheet material as shown in  FIG. 10 . In this state, an ultraviolet ray is applied to make the adhesiveness of the sheet material ineffective, so that the optical components  100  are released from the sheet material. A plurality of aligned optical components  100  is mounted one by one. Thus, the optical components  100  are efficiently picked up and mounted. 
     Further, the optical component  100  is picked up by, for example, suctioning the upper surface  120  of the optical component  100  in vacuum using a mounter such as a die bonder. Here, the upper surface  120  of the optical component  100 , which is accurately ground so as to reduce the surface roughness of the ground surface, has an advantage of facilitating maintenance of vacuum and having a good adsorption property. Thus, it is preferable to grind the upper surface  120  such that the surface roughness is 1.0 μm or less in terms of an arithmetic average roughness Ra. 
     In the light reflecting member  330 , which is the optical component  100  according to the embodiment, the second non-light-control region  114  is ground, such that the boundary between the upper surface  120  and the second light control region  112  is angular. Thus the boundary line can be utilized for adjustment of the mounting position in the mounting step of disposing the light reflecting member  330  on the base member  310 . 
     That is, if the second non-light-control region  114  remains, the upper surface  120  and the second light control region  112  are smoothly continued, and therefore it is difficult to define a unified boundary with the upper surface in a plurality of optical components  100 . Thus, by grinding the second non-light-control region  114  so that the boundary between the upper surface and the second light control region  112  is angular, boundary lines can be accurately defined in a plurality of optical components  100 , and utilized for position adjustment during mounting. 
     Although the optical component  100  according to the embodiment has been described above, optical components applicable to the disclosure in the present embodiment are not limited to those that reflect light. The disclosure in the present embodiment can be applied to, for example, optical components which transmit or refract light. Examples of such optical components include prisms. Therefore, optical components described in the present disclosure are not limited to those that reflect light unless otherwise specified. 
     The structure of a light emitting device having the optical component according to the present disclosure is not limited to the structure of the light emitting device  300  described above. The concepts described in the present disclosure can be applied to, for example, a light emitting device having a constituent element that is not included in the light emitting device  300 , and presence of a difference between such a light emitting device and the light emitting device  300  does not give the reason why the present disclosure cannot be applied. 
     That is, applicability of the present disclosure to a light emitting device does not necessarily require that this light emitting device necessarily and sufficiently has all the constituent elements of the light emitting device  300  disclosed above. For example, when some of the constituent elements of the light emitting device  300  of the embodiment are not described in the claims, those constituent elements are given a degree of freedom of design by those skilled in the art in substitution, omission, modification of shapes, change of materials and the like, without being limited to the constituent elements disclosed in the embodiment, and the claims may still apply to such a device. 
     The optical components described in the embodiments can be used for on-vehicle headlights, projectors, illuminations, backlights for displays, and the like.