Abstract:
The disclosure discloses an optoelectronic element comprising: an optoelectronic unit comprising a first metal layer, a second metal layer, and an outermost lateral surface; an insulating layer having a first portion overlapping the optoelectronic unit and extending beyond the lateral surface, and a second portion separated from the first portion in a cross-sectional view; and a first conductive layer formed on the insulating layer.

Description:
RELATED APPLICATION 
       [0001]    This application is a continuation application of U.S. patent application Ser. No. 13/205,987, filed on Aug. 9, 2011 that is a continuation-in-part application of U.S. patent application Ser. No. 12/840,848 filed Jul. 21, 2010, which is a continuation-in-part application of U.S. patent application Ser. No. 11/674,371, filed on Feb. 13, 2007, which is a continuation-in-part application of U.S. patent application Ser. No. 11/249,680, filed on Oct. 12, 2005; and that is a continuation-in-part application of Ser. No. 12/840,848, filed Jul. 21, 2010, which is a continuation-in-part application of Ser. No. 10/160,588, filed Jun. 29, 2005, which is a continuation-in-part application of Ser. No. 10/604,245, filed Jul. 4, 2003, and claims the right of priority based on Taiwan application Ser. No. 098124681, filed Jul. 21, 2009, and Taiwan application Ser. No. 098146171, filed Dec. 30, 2009, and the content of which is hereby incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to an optoelectronic element, and more particularly, to an optoelectronic element comprising an insulating layer having a first portion overlapping an optoelectronic unit and extending beyond a lateral surface thereof. 
         [0004]    2. Description of the Related Art 
         [0005]    An optoelectronic element, such as a light-emitting diode (LED) package, has been applied widely in optical display devices, traffic signals, data storing devices, communication devices, illumination devices, and medical apparatuses. Similar to the trend of small and slim commercial electronic product, the development of the optoelectronic element also enters into an era of miniature package. One promising packaging design for semiconductor and optoelectronic element is the Chip-Level Package (CLP). 
       SUMMARY OF THE DISCLOSURE 
       [0006]    The present disclosure discloses an optoelectronic element. 
         [0007]    The optoelectronic element comprises an optoelectronic unit comprising a first metal layer, a second metal layer, and an outermost lateral surface; an insulating layer having a first portion overlapping the optoelectronic unit and extending beyond the lateral surface, and a second portion separated from the first portion in a cross-sectional view; and a first conductive layer formed on the insulating layer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The accompanying drawings are included to provide easy understanding of the application, are incorporated herein and constitute a part of this specification. The drawings illustrate embodiments of the application and, together with the description, serve to illustrate the principles of the application. 
           [0009]      FIGS. 1A-1C  illustrate flow charts of a manufacturing process of optoelectronic elements in accordance with an embodiment of the present application. 
           [0010]      FIG. 2A  illustrates a cross-sectional view of an optoelectronic element in accordance with an embodiment of the present application. 
           [0011]      FIG. 2B  illustrates a cross-sectional view of the optoelectronic unit shown in  FIG. 2A . 
           [0012]      FIG. 2C  illustrates a top view of the optoelectronic element shown in  FIG. 2A . 
           [0013]      FIGS. 3A-3F  illustrate flow charts of a manufacturing process of electroplating an electrode on optoelectronic elements in accordance with an embodiment of the present application. 
           [0014]      FIG. 4  illustrates a cross-sectional view of an optoelectronic element in accordance with another embodiment of the present application. 
           [0015]      FIG. 5  illustrates a cross-sectional view of an optoelectronic element in accordance with another embodiment of the present application. 
           [0016]      FIG. 6  illustrates a cross-sectional view of an optoelectronic element in accordance with another embodiment of the present application. 
           [0017]      FIG. 7  illustrates a cross-sectional view of an optoelectronic element in accordance with another embodiment of the present application. 
           [0018]      FIG. 8  illustrates a cross-sectional view of an optoelectronic element in accordance with another embodiment of the present application. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0019]    To better and concisely explain the disclosure, the same name or the same reference number given or appeared in different paragraphs or figures along the specification should has the same or equivalent meanings while it is once defined anywhere of the disclosure. 
         [0020]    The following shows the description of the embodiments of the present disclosure in accordance with the drawings. 
         [0021]      FIGS. 1A-1C  disclose flow charts of a manufacturing process of optoelectronic elements  1  according to an embodiment of the present application. Referring to  FIG. 1A , there is a wafer including a temporary carrier  10 ; a bonding layer  12  formed on the temporary carrier  10 ; and a plurality of optoelectronic units  14  formed on the bonding layer  12 . Referring to  FIG. 1B , a first transparent structure  16  is formed on the bonding layer  12  and the plurality of optoelectronic units  14 . The first transparent structure  16  can cover more than one surface of at least one of the plurality of optoelectronic units  14 . A second transparent structure  18  is formed on the first transparent structure  16 . Referring to  FIG. 1C , the temporary carrier  10  and the bonding layer  12  are removed, and a plurality of conductive structures  2  is formed on the surfaces of the plurality of optoelectronic units  14  and the first transparent structure  16 . The wafer can be separated to form the plurality of optoelectronic elements  1 . 
         [0022]    The temporary carrier  10  and the second transparent structure  18  can support the optoelectronic unit  14  and the first transparent structure  16 . The material of the temporary carrier  10  includes conductive material such as Diamond Like Carbon (DLC), graphite, carbon fiber, Metal Matrix Composite (MMC), Ceramic Matrix Composite (CMC), Polymer Matrix Composite (PMC), Ni, Cu, Al, Si, ZnSe, GaAs, SiC, GaP, GaAsP, ZnSe, InP, LiGaO 2 , LiAlO 2 , or the combination thereof, or insulating material such as sapphire, diamond, glass, epoxy, quartz, acryl, Al 2 O 3 , ZnO, AlN, or the combination thereof. 
         [0023]    The second transparent structure  18  can be transparent to the light emitted from the optoelectronic unit  14 . The material of the second transparent structure  18  can be transparent material such as sapphire, diamond, glass, epoxy, quartz, acryl, SiO x , Al 2 O 3 , ZnO, silicone, or the combination thereof. In addition, the second transparent structure  18  can also be transparent to the light, like the sunlight, from the environment in another embodiment. A thickness of the second transparent structure  18  is about 300 μm to 500 μm. 
         [0024]    The bonding layer  12  can adhesively connect the temporary carrier  10  with the optoelectronic unit  14 , and be easily removed after the second transparent structure  18  is formed on the first transparent structure  16 . The material of the bonding layer  12  can be insulating material, UV tape, or thermal release tape. The insulating material includes but is not limited to benzocyclobutene (BCB), Sub, epoxy, or spin-on-glass (SOG). 
         [0025]    The first transparent structure  16  covers the optoelectronic units  14  to fix and support the optoelectronic units  14  and enhances the mechanical strength of the optoelectronic elements  1 . The first transparent structure  16  can be transparent to the light emitted from the optoelectronic unit  14 . The material of the first transparent structure  16  and the second transparent structure  18  can be the same or different. The coefficient of thermal expansion (CTE) of the first transparent structure  16  is about 50 ppm/° C.˜400 ppm/° C. The material of the first transparent structure  16  can be transparent material such as epoxy, polyimide (PI), BCB, perfluorocyclobutane (PFCB), Sub, acrylic resin, polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), polycarbonate (PC), polyetherimide, fluorocarbon polymer, glass, Al 2 O 3 , SINR, SOG, or the combination thereof. The refractive indices of the first transparent structure  16  and the second transparent structure  18  can be the same or different. A thickness of the first transparent structure  16  is about 200 μm to 300 μm. In addition, the first transparent structure  16  can be transparent to the light from the environment such as the sunlight as well. 
         [0026]    The optoelectronic unit  14  provides luminous energy, electric energy, or both, such as the LED or the solar cell. A thickness of the optoelectronic unit  14  is about 100 μm. When the optoelectronic unit  14  is the LED for emitting light, the refractive index of the first transparent structure  16  is larger than that of the second transparent structure  18  to increase the probability of extracting the light out of the optoelectronic element  1 . When the optoelectronic unit  14  is the solar cell for absorbing light, the refractive index of the first transparent structure  16  is smaller than that of the second transparent structure  18  to increase the probability of the light entering the optoelectronic element  1 . 
         [0027]    Referring to  FIG. 2A  which shows a cross-sectional view of an optoelectronic element  1  in accordance with an embodiment of the present application, the optoelectronic element  1  includes the second transparent structure  18 ; the first transparent structure  16  on the second transparent structure  18 ; the optoelectronic unit  14  on the first transparent structure  16 ; and the conductive structure  2  on the optoelectronic unit  14  and the first transparent structure  16 . The optoelectronic unit  14  includes a first metal layer  142  and a second metal layer  144  formed on a first top surface  141 ; a first bottom surface  143  opposite to the first top surface  141  and close to the second transparent structure  18 ; and more than one lateral surface  140  between the first top surface  141  and the first bottom surface  143 . The conductive structure  2  includes a first insulating layer  22  formed on the optoelectronic unit  14  and the first transparent structure  16  and covering portions of the first metal layer  142  and the second metal layer  144 ; a reflective layer  24  formed on the first insulating layer  22 ; a second insulating layer  26  formed on the first insulating layer  22  and the reflective layer  24  and covering the reflective layer  24 ; a first opening  212  and a second opening  214  formed in the first insulating layer  22  and the second insulating layer  26  to expose the first metal layer  142  and the second metal layer  144  respectively; and an electrode  28  including a first conductive layer  282  and a second conductive layer  284  which are formed on the second insulating layer  26 , and in the first opening  212  and the second opening  214  to electrically connect with the first metal layer  142  and the second metal layer  144  respectively. 
         [0028]    The first insulating layer  22  can electrically isolate the optoelectronic unit  14  from the reflective layer  24  and protect the optoelectronic unit  14  from being damaged by the element diffused from the material of the reflective layer  24 . The first transparent structure  16  includes a second top surface  162  under the first insulating layer  22  and a second bottom surface  166  close to the second transparent structure  18 . The second top surface  162  is substantially lower than the first top surface  141 . However, the second top surface  162  includes a slope  164  adjacent to the first top surface  141 . It is better that the slope  164  can be located over a region of the first top surface  141  between the first and the second metal layers  142  and  144  and the lateral surface  140 . Moreover, a distance between a portion of the second top surface  162  and the second bottom surface  166  can be the same as that between the second bottom surface  166  and the first top surface  141  in another embodiment. 
         [0029]    The first insulating layer  22  can be adhesive to the first transparent structure  16  and/or to the reflective layer  24 . The transparency of the first insulating layer  22  to the light emitted from the optoelectronic unit  14  and/or from the environment is higher than 85%. The CTE of the first insulating layer  22  is smaller than that of the first transparent structure  16 . The CTE of the first insulating layer  22  can be between that of the first transparent structure  16  and the reflective layer  24  preferably. The CTE of the first insulating layer  22  is about 3 ppm/° C. to 200 ppm/° C., preferably 20 ppm/° C. to 70 ppm/° C. The material of the first insulating layer  22  can be the same as or different from that of the first transparent structure  16 . The material of the first insulating layer  22  can be photoresist material for forming the openings so the first insulating layer  22  needs to be cured in the lithography process. The curing temperature of the first insulating layer  22  is not more than 350° C. to avoid damaging the first transparent structure  16  in high temperature. The photoresist material includes but is not limited to AL-polymer, BCB, SINR, Su8, or SOG. The first insulating layer  22  can include a rough surface with a roughness higher than that of the first top surface  141 . A thickness of the first insulating layer  22  is substantially constant, for example, about 2 μm to 3 μm. 
         [0030]    The reflective layer  24  can reflect the light emitted from the optoelectronic unit  14  or from the environment. A thickness of the reflective layer  24  is substantially constant, for example, about 1 μm to 3 μm. The reflective layer  24  overlaps portions of the first metal layer  142  and the second metal layer  144 . The reflective layer  24  can further include a plurality of sub-layers (not shown). The CTE of the reflective layer  24  is about 5 ppm/° C. to 25 ppm/° C. The reflective layer  24  can have a reflectivity of 70% or above to the light emitted from the optoelectronic unit  14  and/or from the environment. The material of the reflective layer  24  includes but is not limited to metal material such as Cu, Al, Sn, Au, Ag, Ti, Ni, Ag—Ti, Ni—Sn, Au alloy, Ni—Ag, Ti—Al, and so on. The reflective layer  24  can include a rough surface with a roughness higher than that of the first top surface  141 . 
         [0031]    The second insulating layer  26  can electrically isolate the first conductive layer  282  and the second conductive layer  284  from the reflective layer  24 , and protect the reflective layer  24  from being damaged by the first conductive layer  282  and the second conductive layer  284 . The second insulating layer  26  can fix the reflective layer  24  and enhances the mechanical strength of the conductive structure  2  as well. The material of the second insulating layer  26  can be the same as and/or different from that of the first insulating layer  22 . The material of the second insulating layer  26  includes but is not limited to photoresist material such as AL-polymer, BCB, SINR, Su8, SOG, PI, or DLC. The second insulating layer  26  can include a rough surface with a roughness higher than that of the first top surface  141 . A thickness of the second insulating layer  26  is substantially constant, for example, about 4 μm to 5 μm. 
         [0032]    The electrode  28  can be integrally formed by evaporation or electroplating. The ratio of the top surface area of the electrode  28  to that of the second transparent structure  18  is not smaller than 50%. The first conductive and second conductive layers  282  and  284  are for receiving external voltage. The material of the first conductive and second conductive layers  282  and  284  can be metal material. The metal material includes but is not limited to Cu, Sn, Au, Ni, Ti, Pb, Cu—Sn, Cu—Zn, Cu—Cd, Sn—Pb—Sb, Sn—Pb—Zn, Ni—Sn, Ni—Co, Au alloy, Au—Cu—Ni—Au, the combination thereof, and so on. The first conductive layer  282  and/or the second conductive layer  284  can include a plurality of sub-layers (not shown). The first conductive layer  282  and/or the second conductive layer  284  can have a reflectivity of 70% or above to the light emitted from the optoelectronic unit  14  and/or from the environment. A thickness of the first conductive layer  282  is a substantially constant, for example, about 12 μm. A thickness of the second conductive layer  284  is substantially constant, for example, about 12 μm. The ratio of the top surface area of the first conductive layer  282  and the second conductive layer  284  to the area of the second bottom surface  166  is more than 50%. 
         [0033]    The optoelectronic unit  14  can be an LED including a light emitting structure  145 , a first dielectric layer  149   a , a passivation layer  147 , a first bonding pad  146 , a second bonding pad  148 , the first metal layer  142 , the second metal layer  144 , and a second dielectric layer  149   b , as  FIG. 2B  shows. The light emitting structure  145  includes a substrate  145   a , a first conductive layer  145   b , an active layer  145   c , and a second conductive layer  145   d . The active layer  145   c  is disposed on the first conductive layer  145   b  and is a light emitting layer. The second conductive layer  145   d  is disposed on the active layer  145   c . The first bonding pad  146  is disposed on the light emitting structure  145  and is electrically connected to the first conductive layer  145   b . The second bonding pad  148  is disposed on the light emitting structure  145  and is electrically connected to the second conductive layer  145   d . The passivation layer  147  is disposed on the light emitting structure  145  and isolates the first bonding pad  146  from the active layer  145   c  and the second conductive layer  145   d . The first dielectric layer  149   a  is disposed on the light emitting structure  145 . The first metal layer  142  is disposed on the light emitting structure  145  and is electrically connected to the first conductive layer  145   b . A portion of the first metal layer  142  is disposed on the first dielectric layer  149   a . The second metal layer  144  is disposed on the light emitting structure  145  and is electrically connected to the second conductive layer  145   d . A portion of the second metal layer  144  is disposed on the first dielectric layer  149   a . The second dielectric layer  149   b  is disposed on the first dielectric layer  149   a . The first dielectric layer  149   a  and the second dielectric layer  149   b  electrically isolate the first metal layer  142  from the second metal layer  144 . A portion of the first dielectric layer  149   a  is a transparent layer, and a surface of the first dielectric layer  149   a  contacting the first metal layer  142  and/or the second metal layer  144  is for reflecting the light emitted from the light emitting structure  145 . The first dielectric layer  149   a  can include a reflective structure in another embodiment. The reflective structure includes distributed bragg reflector (DBR) and/or a reflective film. The reflective film can includes metal material such as Cu, Al, Sn, Au, Ag, Ti, Ni, Ag—Ti, Ni—Sn, Au alloy, Ni—Ag, Ti—Al, and so on. 
         [0034]    There are a first distance d 1  between the first bonding pad  146  and the second bonding pad  148 , a second distance d 2  between the first metal layer  142  and the second metal layer  144 , and a third distance d 3  between the first conductive layer  282  and the second conductive layer  284 , as  FIG. 2B  shows. The first distance d 1  is larger than the second distance d 2  and the third distance d 3 . The second distance d 2  and the third distance d 3  can be the same or difference. The second distance d 2  is larger than the third distance d 3  in an embodiment. The second distance d 2  can also be smaller than the third distance d 3  in another embodiment. The third distance d 3  is about 100 μm to 300 μm. The second transparent structure  18  contains a first width w 1  and the optoelectronic unit  14  contains a second width w 2 . The ratio of the first width w 1  to the second width w 2  is about 1.5 to 3, preferably 2 to 2.5. 
         [0035]    Referring to  FIG. 2C  which shows a top view of the optoelectronic element  1  shown in  FIG. 2A , the first conductive layer  282  contains a truncated corner  286  at a side far from the second conductive layer  284 . There is a forth distance d 4  between the first opening  212  and the reflective layer  24  that is about 25 μm to 75 μm. 
         [0036]    The optoelectronic element  1  can be bonded to a submount through an adhesive material in another embodiment. The adhesive material can be metal material, transparent material, or an anisotropic conductive film. The metal material includes but is not limited to Cu, Sn, Au, Ni, Ti, Pb, Cu—Sn, Cu—Zn, Cu—Cd, Sn—Pb—Sb, Sn—Pb—Zn, Ni—Sn, Ni—Co, Au alloy, Au—Cu—Ni—Au, or the combination thereof. The transparent material includes but is not limited to BCB, Sub, epoxy, or SOG. 
         [0037]      FIGS. 3A-3F  disclose flow charts of a manufacturing process of electroplating the electrode  28  on the optoelectronic unit  14 . Referring to  FIG. 3A , a seed layer  30  is formed on the optoelectronic units  14  and the first transparent structure  16 . A first photoresist  32  is formed on the seed layer  30  to expose portions of the seed layer  30 , as  FIG. 3B  shows. An electroplating layer  34  is electroplated on the portions of the seed layer  30  where the first photoresist  32  does not cover, as  FIG. 3C  shows. Referring to  FIG. 3D , the first photoresist  32  is removed to expose other portions of the seed layer  30 . A second photoresist  36  is formed on the electroplating layer  34 . Then, the exposed portions of the seed layer  30  are removed, as  FIG. 3E  shows. The second photoresist  36  is removed to expose the electroplating layer  34  for forming the electrode  28 , referring to  FIG. 3F . 
         [0038]    Referring to  FIG. 4  which shows a cross-sectional view of an optoelectronic element  4  in accordance with another embodiment of the present application, the optoelectronic element  4  is similar to the optoelectronic element  1  and further includes a recess  40  formed in the second transparent structure  18  such that the second transparent structure  18 , as an optical element, can process the light emitted from the optoelectronic unit  14  or from the environment. The recess  40  can be further formed in the first transparent structure  16 . The shape of the recess  40  can be triangle in the cross-sectional view in this embodiment. 
         [0039]    Referring to  FIG. 5 , the second transparent structure  18  of an optoelectronic element  5  can be trapezoid in another embodiment. The second transparent structure  18  further includes a third bottom surface  182 . The third bottom surface  182  can be a rough surface with a roughness higher than that of the first top surface  141 , or a flat surface. The shape of the second transparent structure  18  includes but is not limited to triangle, semicircle, quarter circle, trapezoid, pentagon, or rectangle in the cross-sectional view. The first transparent structure  16  can also include the same or different shape of the second transparent structure  18 . The second bottom surface  166  can also be a rough surface with a roughness higher than that of the first top surface  141 , or a flat surface in another embodiment. 
         [0040]    An optoelectronic element  6  is similar to the optoelectronic element  5  and further includes a mirror  60  formed under the third bottom surface  182 , as  FIG. 6  shows. The mirror  60  can reflect the light emitted from the optoelectronic unit  14  or from the environment. Referring to  FIG. 7 , an optoelectronic element  7  includes the optoelectronic unit  14 , the conductive structure  2 , the first transparent structure  16 , and the second transparent structure  18 . The second transparent structure  18  contains a first side  184  which is not parallel to the first top surface  141  and a mirror  70  is formed under the first side  184  to reflect light emitted from the optoelectronic unit  14  or from the environment, in another embodiment. The first side  184  can be parabolic curve, arc, or bevel to the first top surface  141  in the cross-sectional view, for example. In another embodiment, an optoelectronic element  8  is similar to the optoelectronic element  7  and the first transparent structure  16  further includes a second side  168  which is not parallel to the first top surface  141 , as  FIG. 8  shows. A mirror  80  is formed under the first side  184  and the second side  168  to reflect light emitted from the optoelectronic unit  14  or from the environment. 
         [0041]    It will be apparent to those having ordinary skill in the art that various modifications and variations can be made to the devices in accordance with the present disclosure without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the present disclosure covers modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.