Patent Publication Number: US-10309612-B2

Title: Light source module having lens with support posts

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority and benefit of Korean Patent Application No. 10-2014-0190519 filed on Dec. 26, 2014, with the Korean Intellectual Property Office, the inventive concept of which is incorporated herein by reference. 
     BACKGROUND 
     The present inventive concept relates to a light source module. 
     Among lenses used in light source modules, a lens having wide beam angle may be used to spread light laterally from a center portion across a large area using the refraction of light. However, when a lens is attached to a substrate in a process of fabricating a light source module, an adhesive may be spread and partly stuck to the lens. Due to the presence of the adhesive on the lens, light emitted by the light source may move along a changed optical path. Accordingly, light emitted externally from the lens may not uniformly spread. In addition, the non-uniform distribution of light may result in poor optical uniformity, such as generation of speckles or mura, in lighting apparatuses or display devices. 
     In addition, since a lens attachment process is required in addition to a light-source attachment process, manufacturing costs and time may be increased. 
     SUMMARY 
     An aspect of the present inventive concept may provide a method of preventing generation of speckles to uniformize light distribution. 
     Another aspect of the present inventive concept may provide a method of simplifying processes of fabricating a light source. 
     According to an aspect of the present inventive concept, a light source module may include a substrate, a light source mounted on the substrate, and an optical device disposed on the light source. The optical device may include a first plane surface facing the light source, a second plane surface disposed opposite to the first plane surface and through which light generated in the light source is emitted externally, and a support disposed on the first plane surface and fixed to the substrate. The support may include a protrusion protruding around a side surface thereof. 
     The protrusion may have a structure extending from a portion spaced apart from the first plane surface in a lateral direction perpendicular to a longitudinal direction of the support. 
     The protrusion may be spaced apart from an upper surface of the substrate and disposed above the substrate. 
     The protrusion may be formed of the same material as the support and formed integrally with the support. 
     The protrusion may have a ring shape including a through-hole, and may be inserted into and fixed to the support through the through-hole. 
     The first plane surface may include a groove depression recessed in a light-emitting direction in a center portion thereof through which an optical axis of the light source passes. 
     The groove depression may be disposed to face the light source above the light source, and a cross-sectional area of the groove depression exposed on the first plane surface may be greater than an area of a light-emitting plane of the light source. 
     The second plane surface may convexly protrude in a moving direction of light, and a central portion thereof through which an optical axis of the light source passes may be concavely recessed toward the light source to have an inflection point. 
     The second plane surface may include a first curved surface having a concavely curved surface recessed along an optical axis toward the light source, and a second curved surface having a convexly curved surface extending continuously from an edge of the first curved surface to the edge of the first plane surface. 
     According to another aspect of the present inventive concept, a light source module may include a substrate, a light source mounted on the substrate, and an optical device disposed on the light source. The optical device may include a first plane surface facing the light source, a second plane surface disposed opposite to the first plane surface and through which light generated in the light source is emitted externally, and a first support disposed on the first plane surface and a second support disposed on an end portion of the first support and fixed to the substrate by an adhesive. The second support may include a protrusion protruding around a side surface thereof. 
     The protrusion may have a structure extending from an end portion of the second support in contact with the first support in a lateral direction perpendicular to a longitudinal direction of the second support, and prevents the adhesive coated on the end portion of the second support from spreading into the first plane surface along the first support. 
     The second support may include a fastening hollow into which the first support is partially inserted and fastened, on a surface in contact with the first support. 
     The second support may be formed of a resin or a metal. 
     The adhesive may include an epoxy adhesive or a solder cream. 
     The light source may be a light-emitting diode (LED) chip or an LED package in which the LED chip is mounted. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above and other aspects, features and advantages of the present inventive concept will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIGS. 1A and 1B  are respectively a cross-sectional view and a plan view schematically illustrating a light source module according to an exemplary embodiment of the present inventive concept; 
         FIG. 2  is a perspective view schematically illustrating a substrate, and a light source and an optical device mounted on the substrate; 
         FIG. 3  is an enlarged cross-sectional view schematically illustrating a light source; 
         FIG. 4  is a perspective view schematically illustrating an optical device of  FIG. 1 ; 
         FIG. 5  is a cross-sectional view of  FIG. 4 ; 
         FIG. 6  is a bottom view of  FIG. 4 ; 
         FIG. 7  is a cross-sectional view schematically illustrating a state in which an optical device is attached to a substrate by an adhesive; 
         FIGS. 8A-8C  schematically illustrates modified examples of a support of the optical device in  FIG. 4 ; 
         FIG. 9  is a perspective view schematically illustrating an optical device according to another exemplary embodiment of the present inventive concept; 
         FIGS. 10A and 10B  are respectively a perspective view and a cross-sectional view schematically illustrating a support of  FIG. 9 ; 
         FIG. 11  is a CIE 1931 coordinate system for explaining a wavelength conversion material employable in an exemplary embodiment of the present inventive concept; 
         FIG. 12  is a flowchart schematically illustrating a method of fabricating a light source module according to an exemplary embodiment of the present inventive concept; 
         FIGS. 13 to 15  are cross-sectional views illustrating various examples of an LED chip usable as a light source according to an exemplary embodiment of the present inventive concept; 
         FIG. 16  is an exploded perspective view schematically illustrating a (bulb type) lighting apparatus according to an exemplary embodiment of the present inventive concept; 
         FIG. 17  is an exploded perspective view schematically illustrating a (L-lamp type) lighting apparatus according to an exemplary embodiment of the present inventive concept; and 
         FIG. 18  is an exploded perspective view schematically illustrating a (plate type) lighting apparatus according to an exemplary embodiment of the present inventive concept. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments will now be described more fully with reference to the accompanying drawings in which some embodiments are shown. The present disclosure may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure is thorough and complete and fully conveys the present disclosure to those skilled in the art. In the drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. 
     It will be understood that when an element or layer is referred to as being “on,” “connected to” or “coupled to” another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present. Like numerals refer to like elements throughout. As used herein, the term. “and/or” includes any and all combinations of one or more of the associated listed items. 
     It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present disclosure. 
     Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element&#39;s or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Meanwhile, when an embodiment can be implemented differently, functions or operations described in a particular block may occur in a different way from a flow described in the flowchart. For example, two consecutive blocks may be performed simultaneously, or the blocks may be performed in reverse according to related functions or operations. 
     A light source module according to an exemplary embodiment of the present inventive concept will be described with reference to  FIGS. 1 and 2 .  FIGS. 1A and 1B  are respectively a cross-sectional view and a plan view schematically illustrating a light source module according to an exemplary embodiment of the present inventive concept, and  FIG. 2  is a perspective view schematically illustrating a substrate, and a light source and an optical device mounted on the substrate. 
     Referring to  FIGS. 1 and 2 , a light source module  100  according to an exemplary embodiment of the present inventive concept may include a substrate  10 , a light source  20  mounted on the substrate  10 , and an optical device  30  disposed on the light source  20 . 
     The substrate  10  may be an FR4-type printed circuit board (PCB) or a flexible PCB, and may be formed of organic resin including an epoxy, triazine, silicone, polyimide, or the like, or another type of organic resin. In addition, the substrate  10  may be formed of a ceramic material, such as silicon nitride, AlN, Al 2 O 3 , or a metal or metal compound, such as MCPCB or MCCL. 
     The substrate  10  may have a bar-type structure having a rectangular shape elongated in a longitudinal direction. However, such a structure of substrate  10  is only an example, and the present inventive concept may not be limited thereto. The substrate  10  may have various structures corresponding to structures of products mounted thereto. 
     Referring to  FIG. 2 , the substrate  10  may include a fiducial mark  11  and a light source mounting area  12 . The fiducial mark  11  and the light source mounting area  12  may guide positions at which the optical device  30  and the light source  20  to be described later are mounted. A plurality of fiducial marks  11  may be arranged around each light source mounting area  12 . 
     In addition, the substrate  10  may include a circuit pattern (not illustrated) electrically connected to the light source  20 . 
     A plurality of light sources  20  may be mounted on a surface of the substrate  10  and arranged in the longitudinal direction. The light source  20  may be a photoelectric device that generates light having a predetermined wavelength by an external applied driving power. For example, the light source  20  may include a semiconductor light-emitting diode (LED) having an n-type semiconductor layer, a p-type semiconductor layer, and an active layer disposed therebetween. 
     The light source  20  may emit blue light, green light, or red light depending on a material contained therein or a combination with a phosphor, or emit white light, UV light, or the like. 
     As the light source  20 , a light-emitting diode (LED) chip having a variety of structures or a light-emitting diode package including the light-emitting diode chip mounted therein may be used. 
       FIG. 3  schematically illustrates the light source  20 . As illustrated in  FIG. 3 , the light source  20  may have, for example, a package structure in which an LED chip  210  is mounted in a package body  220  including a reflective cup  221 . In addition, the LED chip  210  may be covered by an encapsulant  230  containing a phosphor. In the exemplary embodiment of the present inventive concept, the light source  20  is illustrated as an LED package, but is not limited thereto. 
     The package body  220  may correspond to a base member on which the LED chip  210  is mounted and supported, and may be formed of a white molding compound having high level of reflectance. The white molding compound may function to reflect light emitted from the LED chip  210  to increase an amount of light emitted to an exterior. 
     The white molding compound may include a thermosetting resin-based material or a silicone resin-based material, having a high degree of thermal resistance. In addition, a white pigment and filler, a curing agent, a release agent, an antioxidant, an adhesion-improving agent, and the like, may be added to a thermoplastic resin-based material. In addition, the white molding compound may be formed of FR-4, CEM-3, an epoxy material, a ceramic material, or the like. Further, the white molding compound may be formed of a metal such as aluminum (Al). 
     The package body  220  may include a lead frame  222  for forming an electrical connection to an external power source. The lead frame  222  may be formed of a material having excellent electrical conductivity, for example, a metal, such as Al or Cu. When the package body  220  is formed of a metal, an insulating material may be interposed between the package body  220  and the lead frame  222 . 
     In the reflective cup  221  of the package body  220 , the lead frame  222  may be exposed on a bottom surface on which the LED chip  210  is mounted. In addition, the LED chip  210  may be electrically connected to the exposed lead frame  222 . 
     A cross-sectional area of the reflective cup  221  exposed on a top surface of the package body  220  may be greater than an area of the bottom surface of the reflective cup  221 . Here, the cross-section of the reflective cup  221  exposed on the top surface of the package body  220  may define a light-emitting plane of the light source  20 . 
     The LED chip  210  may be encapsulated by the encapsulant  230  formed in the reflective cup  221  of the package body  220 . The encapsulant  230  may include a wavelength-converting material. 
     The wavelength-converting material may include, for example, at least one type of phosphor excited by light generated by the LED chip  210  and emitting light having a wavelength different from the light generated by the LED chip  210 . Through the wavelength-converting material, various colors of light including white light may be emitted. 
     For example, when the LED chip  210  emits blue light, white light may be emitted through a combination thereof with yellow, green, red, and/or orange phosphors. Also, the LED chip  210  may be configured to include at least one of LED chips emitting purple, blue, green, red, and infrared light. In this case, the LED chip  210  may control a color rendering index (CRI) in a range from about 40 to about 100, and may generate a variety of white light having a color temperature in a range of about 2,000K to about 20,000K. In addition, the LED chip  210  may emit visible light having a purple, blue, green, red, or orange color, or infrared light as needed, and control the color according to an environment or mood. In addition, the LED chip  210  may emit light having a specific wavelength to promote plant growth. 
     White light generated by combining yellow, green, and red phosphors with a blue LED and/or combining at least one of green LED and red LED therewith may have two or more peak wavelengths, and may be located on the line connecting (x, y) coordinates of (0.4476, 0.4074), (0.3484, 0.3516), (0.3101, 0.3162), (0.3128, 0.3292), (0.3333, 0.3333) in the CIE 1931 chromaticity diagram illustrated in  FIG. 11 . Alternatively, the white light may be located in a zone surrounded by the line and a black body radiation spectrum. The color temperature of the white light may be in a range of about 2,000K to about 20,000K. 
     Phosphors may have a compositional formula and colors as follows. 
     Oxide group: yellow and green Y 3 Al 5 O 12 :Ce, Tb 3 A 1   5 O 12 :Ce, Lu 3 Al 5 O 12 :Ce 
     Silicate group: yellow and green (Ba, Sr) 2 SiO 4 :Eu, yellow and orange (Ba, Sr) 3 SiO 5 :Ce 
     Nitride group: green β-SiAlON:Eu, yellow La 3 Si 6 N 11 :Ce, orange α-SiAlON:Eu, red CaAlSiN 3 :Eu, Sr 2 Si 5 N 8 :Eu, SrSiAl 4 N 7 :Eu, SrLiAl 3 N 4 :Eu, Ln 4−x (Eu z M 1−z ) x Si 12−y Al y O 3+x+ N 18−x−y  (0.5≤x≤3, 0&lt;z&lt;0.3, and 0&lt;y≤4) (Here, Ln is at least one element selected from the group consisting of a group IIIa element and a rare earth element, and M is at least one element selected from the group consisting of Ca, Ba, Sr, and Mg.) 
     Fluoride group: KSF-based red K 2 SiF 6 :Mn 4+ , K 2 TiF 6 :Mn 4+ , NaYF 4 :Mn 4+ , NaGdF 4 :Mn 4+   
     The compositions of phosphor need to conform to stoichiometric requirements, and each element may be substituted with a different element within a corresponding group in the periodic table. For example, Sr may be substituted with Ba, Ca, or Mg in the alkaline-earth (II) group and Y may be substituted with Tb, Lu, Sc, or Gd in the lanthanide group. In addition, an activator, Eu, may be substituted with Ce, Tb, Pr, Er, or Yb depending on a preferred energy level. The activator may be used alone, or a co-activator may be additionally used to change characteristics thereof. 
     In addition, a material such as a quantum dot (QD) may be used as an alternative material for phosphor, and the phosphor and the QD may be used in combination or alone. 
     The QD may have a structure consisting of a core (having a radius of about 3 nm to 10 nm), such as CdSe and InP, a shell (having a thickness of about 0.5 nm to 2 nm), such as ZnS and ZnSe, and a ligand for stabilizing the core and shell, and implement a variety of colors according to sizes thereof. 
     Referring to  FIG. 1  and  FIG. 2 , the optical device  30  may be mounted on the substrate  10 , and may cover the plurality of light sources  20 . The number of the optical devices  30  may correspond to the number of the light sources  20 . In addition, the optical device  30  may be mounted on the substrate  10  so as to cover each light source  20  through the fiducial mark  11  corresponding to each light source mounting area  12 . 
     Meanwhile, the substrate  10  may further include a connector  50  for connecting the light source  20  to an external power source, in addition to the plurality of light sources  20  and optical devices  30 . The connector  50  may be mounted on an end portion of the substrate  10 . 
     Hereinafter, various exemplary embodiments of an optical device used in the light source module will be described in more detail. 
     An optical device applicable to a light source module according to an exemplary embodiment of the present inventive concept will be described with reference to  FIGS. 4 to 6 .  FIG. 4  is a perspective view schematically illustrating the optical device,  FIG. 5  is a cross-sectional view of  FIG. 4 , and  FIG. 6  is a bottom view of  FIG. 4 . 
     Referring to  FIGS. 4 to 6 , an optical device  30  may be disposed on a light source  20  to control beam angle of light emitted by the light source  20 . Here, the light source  20  may include, for example, a light-emitting device package. In addition, the optical device  30  may include a wide beam angle lens spreading light emitted from a light-emitting device package to implement a wide beam angle. 
     As illustrated in  FIGS. 4 and 5 , the optical device  30  may include a first plane surface  31  disposed on or above the light source  20 , a second plane surface  32  disposed opposite to the first plane surface  31 , and a support  34  disposed on the first plane surface  31 . 
     The first plane surface  31  may be a surface disposed on or above the light source  20  and facing the light source  20 , and may correspond to a bottom surface of the optical device  30 . The first plane surface  31  may have a flat circular-shaped cross-sectional structure overall in plan view. 
     The first plane surface  31  may include a groove depression  33  recessed in a light-emitting direction in the center portion through which an optical axis Z of the light source  20  passes. The groove depression  33  may have a structure rotationally symmetrical with respect to the optical axis Z, and a surface of the groove depression  33  thereof may be defined as a plane of incidence on which light emitted by the light source  20  is incident. Accordingly, light generated by the light source  20  may pass through the groove depression  33  to proceed to the inside of the optical device  30 . 
     The groove depression  33  may be open to the exterior through the first plane surface  31 . A cross-sectional area of the groove depression  33  thereof exposed to the first plane surface  31  may be greater than an area of the light-emitting plane of the light source  20 . In addition, the groove depression  33  may be disposed above the light source  20  to face the light source  20  and cover the light source  20 . 
     The second plane surface  32  may be disposed opposite to the first plane surface  31 . The second plane surface  32  may define a light-emitting plane in which light entered through the groove depression  33  is emitted to the exterior, and corresponds to an upper surface of the optical device  30 . An optical axis Z may pass through a central portion of the second plane surface  32 . The second plane surface  32  may have an overall dome shape, bulged upwardly, that is, in the light-emitting direction, from an edge connected to the first plane surface  31 , and the central portion is concavely recessed toward the groove depression  33  to have an inflection point. 
     As illustrated in  FIG. 5 , the second plane surface  32  may include a first curved surface  32   a  recessed along the optical axis Z toward the groove depression  33  to have a concavely curved surface, and a second curved surface  32   b  extending continuously from an edge of the first curved surface  32   a  to the edge of the first plane surface  31  to have a convexly curved surface. 
     The support  34  may protrude from the first plane surface  31  toward the substrate  10 , and at least two supports  34  may be included. In addition, the support  34  may be arranged around the groove depression  33 . In the exemplary embodiment of the present disclosure, three supports  34  may be arranged, but the number of the support  34  may vary as needed. A plurality of the supports  34  may be arranged around the groove depression  33  or the light source  20 . The plurality of the supports  34  may be fixed at the points that will keep the optical device in a stable state. In one embodiment, the support  34  may be formed of the same material as the optical device  30 . In another embodiment, the support  34  may be formed of a metal, which may refer to the support  34  made of metal or coated with a metal. 
       FIG. 7  schematically illustrates a state in which the optical device  30  is attached to the substrate  10  by an adhesive P. 
     As illustrated in  FIG. 7 , the support  34  may be fixed to a top surface  14  of the substrate  10  by the adhesive P, when the optical device  30 , for example, is mounted on the substrate  10 . In addition, the first plane surface  31  may be disposed on or above the light source  20 , and the groove depression  33  may face the light source  20 . 
     The support  34  may have a bar-shaped structure, and extend in a longitudinal direction parallel to the optical axis Z. In some embodiments, the support  34  may include a lower portion  38  having a bar-shaped structure with a lower end  38   a  mounted to the top surface  14  of the substrate and an upper portion  39  having a bar-shaped structure with an upper end  39   a  disposed on the first plane surface  31 . The support  34  may include a protrusion  35  radially protruding from a side surface thereof. The protrusion  35  may be in a middle portion between the lower portion  38  and the upper portion  39 . In some embodiments, the protrusion  35  may be located in a substantially central position of the support  34  in a longitudinal direction. In some embodiments, the protrusion  35  may be located away from the central position of the support  34  in the longitudinal direction. A cross section of the lower portion  38  and the upper portion  39  may be of any suitable shapes such as circular, square, rectangular, or hexagonal. A cross-sectional area of the lower portion  38  and the upper portion  39  may be the same or different. An edge portion of the protrusion  35  may be of any suitable shapes such as circular, square, rectangular, or hexagonal shape. 
     The protrusion  35  may be spaced apart from the first plane surface  31  by a first predetermined distance and spaced apart from the top surface  14  of the substrate  10  by a second predetermined distance. The first predetermined distance and the second predetermined distance may be the same or different. The protrusion  35  may extend in a lateral direction, that is, perpendicular to a longitudinal direction of the support  34 . For example, the protrusion  35  may extend in a disc shape, concentric with an axis passing through a center of the bar-shaped structure of the support  34 . 
     The protrusion  35  may have a structure such as an engaging shoulder in a substantially central position of the support  34  in a longitudinal direction, and function as a sort of stopper blocking movement of the adhesive P coated on an end portion or the lower end of the support  34 . The movement or spreading of the adhesive P may occur during a reflow process which will be described later. In some embodiments, the support  34  may be configured to have a structure or a dimension according to a reflow process. For example, the size and the location of the protrusion  35  of the support  34  may be determined according to the movement or moving path of the adhesive during the reflow process. For example, an area of protrusion in plan view and a distance of the protrusion to the top surface  14  of the substrate or a length of the lower portion  38  of the support  34  may be determined based on the reflow process such that the adhesive P coated on the end portion of the support  34  may be prevented from spreading to the first plane surface  31 . 
     The protrusion  35  may be formed of the same material as the support  34  and integrated with the support  34 . However, the material of the protrusion  35  may not be limited thereto. 
     In one embodiment as illustrated in  FIG. 8A , a protrusion  37  may be formed as a separate component from a support  36 . 
     The protrusion  37  may have a ring shape including a through-hole  37   a . In addition, the protrusion  37  may be inserted to the support  36  through the through-hole  37   a  to be fixed. In this case, the location at which the protrusion  37  is fixed may be optionally adjusted according to a designed structure and/or the reflow process 
     In another embodiment as shown in  FIGS. 8B and 8C , the protrusion  37 - 1  may be a cone shape with a surface sloped toward the top surface of the substrate  10 . That is, the protrusion may have an inclined surface  37 - 1   b  toward the top surface  14  of the substrate or may be formed having an angle to the top surface  14  of the substrate. 
     It should be appreciated that the protrusion may be any suitable shape that blocks the spreading of the adhesive toward the first plane surface  31  of the optical device  30 . 
     The optical device  30  may be formed of a resin material having translucency, for example, polycarbonate (PC), polymethylmethacrylate (PMMA), and acrylic. In addition, the optical device  30  may be formed of a glass material, but is not limited thereto. 
     The optical device  30  may include a light-spreading material in the range of 3% to 15%, approximately. As the light-spreading material, for example, at least one material selected from the group consisting of SiO 2 , TiO 2 , and Al 2 O 3  may be included. When the content of the light-spreading material is less than 3%, there may be a problem in that a light-spreading effect is not obtained since light is not sufficiently spread. In addition, when the content of the light-spreading material is more than 15%, the amount of light emitted externally through the optical device  30  may be reduced, and thus light extraction efficiency may be decreased. 
     The optical device  30  may be formed by injecting a fluidal solvent into a mold and solidifying the fluidal solvent. For example, the optical device  30  may be formed by injection molding, transfer molding, compression molding, or the like. 
     An optical device according to another exemplary embodiment of the present inventive concept will be described with reference to  FIGS. 9 and 10 .  FIG. 9  is a cross-sectional view schematically illustrating an optical device according to another exemplary embodiment of the present inventive concept, and  FIGS. 10A and 10B  are respectively a perspective view and a cross-sectional view schematically illustrating a support of  FIG. 9 . 
     A basic configuration of the optical device  40  according to the exemplary embodiment illustrated in  FIGS. 9 and 10  may be substantially the same as that of the optical device  30  according to the exemplary embodiment illustrated in  FIGS. 4 to 8 . However, since a structure of a support  44  is different from the support  34  according to the exemplary embodiment illustrated in  FIGS. 4  to  8 , duplicated descriptions will be omitted and the structure of the support will be mainly described hereinafter. 
     Referring to  FIGS. 9 and 10 , the optical device  40  according to the exemplary embodiment of the present inventive concept may include a first plane surface  41  disposed on a light source  20 , a second plane surface  42  disposed opposite to the first plane surface  41 , and a first support  44  and a second support  45  disposed on the first plane surface  41 . 
     The first plane surface  41  may be a surface disposed on or above the light source  20  and facing the light source  20 , and may correspond to a bottom surface of the optical device  40 . 
     The first plane surface  41  may include a groove depression  43  recessed in a light-emitting direction in a center portion thereof. The groove depression  43  may have a structure rotationally symmetrical with respect to the optical axis Z passing the center portion of the optical device  40 , and a surface thereof may be defined as a plane of incidence on which light emitted by the light source  20  is incident. 
     The second plane surface  42  may be disposed opposite to the first plane surface  41 . The second plane surface  42  may define a light-emitting plane in which light entered through the groove depression  43  is emitted externally, and corresponds to an upper surface of the optical device  40 . 
     The second plane surface  42  may include a first curved surface  42   a  recessed along the optical axis Z toward the groove depression  43  to have a concavely curved surface, and a second curved surface  42   b  extending continuously from an edge of the first curved surface  42   a  to the edge of the first plane surface  41  to have a convexly curved surface. 
     Basic structures of the first plane surface  41  and the second plane surface  42  may be substantially the same as those of the first plane surface  31  and the second plane surface  32  described with reference to  FIGS. 4 and 5 . Accordingly, detailed descriptions thereof will be omitted. 
     The first support  44  may protrude toward the light source  20  and may be disposed on the first plane surface  41 . At least two first supports  44  may be disposed on the first plane surface  41 . In addition, the first supports  44  may be arranged around the groove depression  43  which is in the center portion of the first plane surface  41 . 
     The first support  44  may have a bar-shaped structure and extend parallel to the optical axis Z. The first support  44  may be formed of the same material as the optical device  40 , and integrated with the optical device  40 . 
     The second support  45  may be disposed on an end portion of the first support  44 . In addition, the second support  45  may extend in a longitudinal direction to be aligned with the first support  44 . When the optical device  40  is mounted on the substrate  10 , the second support  45  may be fixed to the substrate  10  by an adhesive P. 
     The second support  45  may include a fastening hollow  47  on a surface in contact with the first support  44 . The first support  44  may be partially inserted into the fastening hollow  47  and fastened to the second support  45 . The second support  45  may be fixed in combination with the first support  44  through the fastening hollow  47 . 
     The second support  45  may include a protrusion  46  radially protruding from a side surface thereof. The protrusion  46  may have a structure laterally extending in a direction perpendicular to a longitudinal direction of the second support  45  at an end portion of the second support  45  in contact with the first support  44 . For example, the protrusion  46  may extend in a disc shape, with the second support  45  as a center. In addition, the second support  45  may form a T-shaped structure overall, together with the protrusion  46 . The protrusion  46  may form a structure such as an engaging shoulder between the first support  44  and the second support  45 , and function to prevent the adhesive P coated on the end portion of the second support  45  from spreading to the first plane surface  41  along the first support  44 . 
     The second support  45  may be formed of the same material as the first support  44 . In addition, the second support  45  may be formed of a metal. In this case, the second support  45  may be formed at an end of the first support  44  through metal coating. 
     It will be appreciated that a support is not limited to the exemplary embodiments. The support can be any configuration that functions to support an optical device and prevent or reduce the spreading of the adhesive attaching to a lower end of the support to the optical device during amounting and/or a reflow processes. For example, the support may include an elongated portion substantially parallel to an optical axis Z and a protrusion extending away from the elongated portion. In one example, the protrusion may have a surface parallel to the top surface of the substrate, and is formed around the elongated portion and symmetrically relative to the elongated portion. In another example, the protrusion may be formed asymmetrically relative to the elongated portion. 
     Thus, since the optical device  30  according to the exemplary embodiment of the present inventive concept, unlike normal optical devices, includes the protrusion  35  having an engaging shoulder structure protruding from the central position of the support  34 , the adhesive P may be prevented from spreading to a bottom surface of the optical device  30 , that is, the first plane surface  31 . Accordingly, the adhesive P may be prevented from attaching to the first plane surface  31  (please refer to  FIG. 7 ). 
     The adhesive P may be an epoxy adhesive. In addition, the adhesive P may include a solder cream. In particular, when the second support  45  is formed of a metal, the optical device  40  may be attached to the substrate  10  using the solder cream as an adhesive, similar to a case in which a normal electronic device is mounted. 
     Hereinafter, a method of fabricating a light source module according to an exemplary embodiment of the present disclosure will be described with reference to  FIG. 12  together with  FIGS. 1 and 2 .  FIG. 12  is a schematic flowchart illustrating a method of fabricating a light source module according to an exemplary embodiment of the present disclosure. 
     First, an adhesive P may be coated on a substrate  10  (S 10 ). The adhesive P may be coated on a light source mounting area  12  and a fiducial mark  11  disposed on the substrate  10  using screen printing. The adhesive P may include an epoxy adhesive or a solder cream. 
     Next, a light source  20  and an optical device  30  may be mounted on the substrate  10  (S 20 ). The light source  20  and the optical device  30  may be respectively mounted on the light source mounting area  12  and fiducial mark  11  of the substrate  10 . In addition, circuit components, such as a connector  50  and a capacitor (not illustrated) may be further mounted on the substrate  10 . 
     Next, a reflow process may be performed at a predetermined temperature (S 30 ). Through such a reflow process, the light source  20  and the optical device  30  may be tightly fixed to the substrate  10  by the adhesive P. 
     Next, visual inspection to examine whether the light source module is defective or not may be performed (S 40 ). The visual inspection may be performed using an inspection apparatus or directly performed by an operator. The light source module  100  determined as being non-defective may be shipped as a product through a packaging process. 
     Thus, in the method of fabricating a light source module according to the exemplary embodiment of the present disclosure, the light source and the optical device are simultaneously mounted on the substrate, and attached through a single reflow process. Accordingly, compared to a normal method in which the light source and the optical device are mounted respectively through separate processes, the method may have an advantage in that time and costs for fabricating the light source module are reduced. 
     That is, a normal method of fabricating a light source module may include mounting circuit components including a light source on a substrate, performing a reflow process, and then performing a visual inspection to examine whether the light source module is defective or not. The method may further include coating the light source module determined as being non-defective with an adhesive, mounting an optical device, performing a reflow process, and then performing a visual inspection before shipping a final product. 
     Thus, since a lens attachment process is required in addition to a light-source attachment process, manufacturing costs and time may increase due to an epoxy adhesive injection apparatus, a hardening and reflowing apparatus, and the additional process. 
     According to the exemplary embodiment of the present disclosure, since a light source and an optical device are simultaneously mounted on a substrate, such problems may be solved. In particular, since a support fixing the optical device on the substrate may be partly formed of a metal, a solder cream may be used as an adhesive such as in the case of the light source. Accordingly, additional processes and apparatuses for attaching the optical device to the substrate may be omitted. In addition, since the support includes a protrusion having an engaging shoulder structure, the adhesive may be prevented from spreading into a bottom of the optical device and being stuck thereto. 
     LED chips according to various exemplary embodiments of the present disclosure will be described with reference to  FIGS. 13 to 15 .  FIGS. 13 to 15  are cross-sectional views illustrating various examples of an LED chip usable as a light source. 
     Referring to  FIG. 13 , an LED chip  210  may include a first conductivity-type semiconductor layer  212 , an active layer  213 , and a second conductivity-type semiconductor layer  214 , sequentially stacked on a growth substrate  211 . 
     The first conductivity-type semiconductor layer  212  stacked on the growth substrate  211  may be an n-type nitride semiconductor layer doped with n-type impurities. In addition, the second conductivity-type semiconductor layer  214  may be a p-type nitride semiconductor layer doped with p-type impurities. However, in some embodiments, the first and second conductivity-type semiconductor layers  212  and  214  may be stacked interchangeably. Such first and second conductivity-type semiconductor layers  212  and  214  may have a compositional formula of Al x In y Ga (1−x−y) N (here, 0≤x&lt;1, 0≤y&lt;1, and 0≤x+y&lt;1), for example, GaN, AlGaN, InGaN, or AlInGaN. 
     The active layer  213  disposed between the first and second conductivity-type semiconductor layers  212  and  214  may emit light having a predetermined energy, generated by electron-hole recombination. The active layer  213  may include a material having a smaller energy bandgap than the first and second conductivity-type semiconductor layers  212  and  214 . For example, when the first and second conductivity-type semiconductor layers  212  and  214  are GaN-based compound semiconductors, the active layer  213  may include an InGaN-based compound semiconductor having a smaller energy bandgap than GaN. In addition, the active layer  213  may have a multiple quantum well (MQW) structure, for example, an InGaN/GaN structure, in which quantum well layers and quantum barrier layers are alternately stacked. However, the active layer  213  may not be limited thereto, and may have a single quantum well (SQW) structure. 
     The LED chip  210  may include first and second electrode pads  215  and  216  electrically connected to the first and second conductivity-type semiconductor layers  212  and  214 , respectively. The first and second electrode pads  215  and  216  may be exposed and disposed in the same direction. In addition, the first and second electrode pads  215  and  216  may be electrically connected to a substrate by a wire bonding method or a flip-chip bonding method. 
     An LED chip  310  illustrated in  FIG. 14  may include a semiconductor laminates formed on a growth substrate  311 . The semiconductor laminates may include a first conductivity-type semiconductor layer  312 , an active layer  313 , and a second conductivity-type semiconductor layer  314 . 
     The LED chip  310  may include first and second electrode pads  315  and  316  respectively connected to the first and second conductivity-type semiconductor layers  312  and  314 . 
     The first electrode pad  315  may include a conductive via  315   a  passing through the second conductivity-type semiconductor layer  314  and the active layer  313  to be connected to the first conductivity-type semiconductor layer  312 , and an electrode extension portion  315   b  connected to the conductive via  315   a . The conductive via  315   a  may be surrounded by an insulating layer  317  to be electrically isolated from the active layer  313  and the second conductivity-type semiconductor layer  314 . The conductive via  315   a  may be disposed on an area where the semiconductor laminates is etched. The number, shape, or pitch of the conductive via  315   a , or a contact area with the first conductivity-type semiconductor layer  312  may be appropriately designed to reduce contact resistance. In addition, the conductive via  315   a  may be arranged in rows and columns on the semiconductor laminates to improve current flow. 
     The second electrode pad  316  may include an ohmic contact layer  316   a  and an electrode extension portion  316   b  on the second conductivity-type semiconductor layer  314 . 
     An LED chip  410  illustrated in  FIG. 15  may include a growth substrate  411 , a first conductivity-type semiconductor base layer  412  formed on the growth substrate  411 , and a plurality of light-emitting nanostructures  413  formed on the first conductivity-type semiconductor base layer  412 . In addition, the LED chip  410  may further include an insulating layer  414  and a filling part  417 . 
     The light-emitting nanostructure  413  may include a first conductivity-type semiconductor core  413   a , an active layer  413   b  and a second conductivity-type semiconductor layer  413   c , sequentially formed as shell layers on a surface of the first conductivity-type semiconductor core  413   a . In the present exemplary embodiment, it is illustrated that each of the light-emitting nanostructures  413  has a core-shell structure, but the structure of the light-emitting nanostructures  413  is not limited thereto and each of the light-emitting nanostructures  413  may have any other structure such as a pyramid structure. 
     The first conductivity-type semiconductor base layer  412  may be a layer providing a growth plane for the light-emitting nanostructure  413 . The insulating layer  414  may provide an open area for growing the light-emitting nanostructure  413 , and may be a dielectric material, such as SiO 2  or SiN x . The filling part  417  may structurally stabilize the light-emitting nanostructure  413  and function to transmit or reflect light. Meanwhile, when the filling part  417  includes a light-transmitting material, the filling part  417  may be formed of a transparent material, such as SiO 2 , SiNx, an elastic resin, silicone, an epoxy resin, a polymer, or plastic. As needed, when the filling part  417  includes a reflective material, the filling part  417  may be formed of a polymer material such as polyphthalamide (PPA), and a high reflective metal powder or a ceramic powder. The high reflective ceramic powder may be at least one selected from the group consisting of TiO 2 , Al 2 O 3 , Nb 2 O 5 , Al 2 O 3 , and ZnO. The high reflective metal may be Al or silver Ag. 
     The first and second electrode pads  415  and  416  may be disposed on a lower surface of the light-emitting nanostructure  413 . The first electrode pad  415  may be disposed on an exposed surface of the first conductivity-type base layer  412 , and the second electrode pad  416  may include an ohmic contact layer  416   a  and an electrode extension portion  416   b , formed under the light-emitting nanostructure  413  and the filling part  417 . Otherwise, the ohmic contact layer  416   a  and the electrode extension portion  416   b  may be formed integrally. 
     Various lighting apparatuses including a light source module according to an exemplary embodiment of the present disclosure will be described with reference to  FIGS. 16 to 18 . 
       FIG. 16  schematically illustrates a lighting apparatus according to an exemplary embodiment of the present disclosure. 
     Referring to  FIG. 16 , a lighting apparatus  1000  according to the exemplary embodiment of the present disclosure may be a bulb-type lamp, and may be used as an indoor lighting device, for example, a downlight. 
     The lighting apparatus  1000  may include a housing  1020  having an electrical connection structure  1030 , and a light source module  1010  mounted on the housing  1020 . In addition, the lighting apparatus  1000  may further include a cover  1040  mounted on the housing  1020  and covering the light source module  1010 . 
     The light source module  1010  may be substantially the same as the light source module  100  described with reference to  FIG. 1 . Accordingly, detailed descriptions thereof will be omitted. The light source module  1010  may include a plurality of light sources  20  and a plurality of optical devices  30  mounted on a substrate  1011 . 
     The housing  1020  may function as a frame supporting the light source module  1010 , and a heat sink emitting heat generated in the light source module  1010  to the outside. For this, the housing  1020  may be formed of a rigid material having a high thermal conductivity, for example, a metal such as Al, a heat-dissipating resin, or the like. 
     A plurality of heat-dissipating fins  1021  for increasing a surface area in contact with ambient air to improve a heat-dissipating efficiency may be formed on an outer side surface of the housing  1020 . 
     An electrical connection structure  1030  electrically connected to the light source module  1010  may be disposed on the housing  1020 . The electrical connection structure  1030  may include a terminal  1031 , and a driver  1032  supplying driving power received through the terminal  1031  to the light source module  1010 . 
     The terminal  1031  may install the lighting apparatus  1000  in a socket, for example, to be fixed and electrically connected thereto. In the exemplary embodiment of the present disclosure, the terminal  1031  is described as having a sliding pin-type structure, but is not limited thereto. As needed, the terminal  1031  may have an Edison-type structure installed by turning a screw thread. 
     The driver  1032  may function to convert external driving power into an appropriate current source for driving the light source module  1010  and supply the converted current source. The driver  1032  may include, for example, an AC-DC converter, parts for a rectifier circuit, a fuse, or the like. In addition, the driver  1032  may further include a communication module implementing a remote control function, as needed. 
     The cover  1040  may be installed in the housing  1020  to cover the light source module  1010 , and may have a convex lens shape or a bulb shape. The cover  1040  may be formed of a light-transmitting material, and include a light-spreading material. 
       FIG. 17  is an exploded perspective view schematically illustrating a lighting apparatus according to another exemplary embodiment of the present disclosure. Referring to  FIG. 17 , a lighting apparatus  1100  may be, for example, a bar-type lamp, and include a light source module  1110 , a housing  1120 , a terminal  1130 , and a cover  1140 . 
     The light source module  1110  may be substantially the same as the light source module  100  illustrated in  FIG. 1 . Accordingly, detailed descriptions thereof will be omitted. The light source module  1110  may include a plurality of light sources  20  and a plurality of optical devices  30  mounted and arranged along a substrate  1111 . 
     The housing  1120  may have the light source module  1110  mounted on and fixed to one surface  1122  thereof, and release heat generated in the light source module  1110  to the outside. In this regard, the housing  1120  may be formed of a material having a high thermal conductivity, for example, a metal, and a plurality of heat dissipating fins  1121  may be formed to protrude on both side surfaces thereof. 
     The cover  1140  may be fastened to a fastening hollow  1123  of the housing  1120  to cover the light source module  1110 . 
     In addition, the cover  1140  may have a semi-circularly curved surface so that light generated in the light source module  1110  is uniformly emitted externally overall. An overhanging  1141  engaged with the fastening hollow  1123  of the housing  1120  may be formed in a longitudinal direction on a bottom surface of the cover  1140 . 
     The terminal  1130  may be disposed at least open one of two end portions of the housing  1120  in the longitudinal direction to supply power to the light source module  1110 . The terminal  1130  may further include an electrode pin  1133  protruding outwardly. 
       FIG. 18  is an exploded perspective view schematically illustrating a lighting apparatus according to another exemplary embodiment of the present disclosure. Referring to  FIG. 18 , a lighting apparatus  1200  may have, for example, a surface light source type structure, and include a light source module  1210 , a housing  1220 , a cover  1240 , and a heat sink  1250 . 
     The light source module  1210  may be substantially the same as the light source module  100  illustrated in  FIG. 1 . 
     Accordingly, detailed descriptions thereof will be omitted. The light source module  1210  may include a plurality of light sources  20  and a plurality of optical devices  30  mounted and arranged along a substrate  1211 . 
     The housing  1220  may have a box-type structure including one surface  1222  on which the light source module  1210  is mounted, and a side surface  1224  extending from edges of the one surface  1222 . The housing  1220  may be formed of a material having a high thermal conductivity, for example, a metal, so as to release heat generated in the light source module  1210  to the outside. 
     A hole  1226  to which a heat sink  1250 , to be described later, is to be inserted and engaged may be formed to pass through the one surface  1222  of the housing  1220 . In addition, the substrate  1211  of the light source module  1210  mounted on the one surface  1222  may be partly engaged on the hole  1226  to be exposed to the outside. 
     The cover  1240  may be fastened to the housing  1220  to cover the light source module  1210 . In addition, the cover  1240  may have a flat structure overall. 
     The heat sink  1250  may be engaged with the hole  1226  through the other surface  1225  of the housing  1220 . In addition, the heat sink  1250  may be in contact with the light source module  1210  through the hole  1226  to release heat generated in the light source module  1210  to the outside. In order to increase heat dissipating efficiency, the heat sink  1250  may include a plurality of heat dissipating fins  1251 . The heat sink  1250 , like the housing  1220 , may be formed of a material having a high thermal conductivity. 
     Lighting apparatuses using light emitting devices may be roughly divided into indoor lighting apparatuses and outdoor lighting apparatuses according to purposes thereof. The indoor LED lighting apparatuses may be bulb-type lamps, fluorescent lamps (LED-tubes), or flat-type lighting apparatuses, and mainly for retrofitting existing lighting apparatuses. The outdoor LED lighting apparatuses may be street lights, guard lamps, floodlights, decorative lights, or traffic lights. 
     In addition, such an LED lighting apparatus may be utilized as interior or exterior light sources for vehicles. As interior light sources, the LED lighting apparatuses may be used as various light sources for vehicle interior lights, such as reading lamps, and instrument panels. As exterior light sources, the LED lighting apparatuses may be used as all types of light sources, such as headlights, brake lights, turn indicators, fog lights, and running lights. 
     Further, the LED lighting apparatuses may be used as light sources for robots or various types of mechanical equipment. In particular, an LED lighting apparatus using light within a particular wavelength band may promote the growth of plants, or stabilize the mood of a person or cure diseases as an emotional lighting apparatus. 
     As set forth above, according to the exemplary embodiments of the present disclosure, a light source module capable of preventing generation of speckles, uniformizing light distribution, and simplifying manufacturing processes thereof, can be provided. 
     While exemplary embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the invention as defined by the appended claims.