Abstract:
Disclosed are optical devices and methods of manufacturing optical devices. An optical device can include a substrate; an optical emitter chip affixed to the front surface of the substrate; and an optical sensor chip affixed to the front surface of the substrate. The optical sensor chip can include a main sensor and a reference sensor. The optical device can include an opaque dam separating the main optical sensor and the reference sensor. The optical device can include a first transparent encapsulation block encapsulating the optical emitter chip and the reference optical sensor and a second transparent encapsulation block encapsulating the main optical sensor. The optical device can include an opaque encapsulation material encapsulating the first transparent encapsulation block and the second transparent encapsulation block with a first opening above the main optical sensor and a second opening above the optical emitter chip.

Description:
CROSS-REFERENCES TO APPLICATIONS 
       [0001]    This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/257,198, filed on Nov. 18, 2015, and titled “OPTICAL DEVICE,” the contents of which are incorporated herein by reference in their entirety. 
         [0002]    The contents of commonly-assigned Patent Cooperation Treaty Application No. PCT/SG2015/050224, filed on Jul. 22, 2015, and titled “OPTOELECTRONIC MODULES INCLUDING AN IMAGE SENSOR HAVING REGIONS OPTICALLY SEPARATED FROM ONE ANOTHER,” are hereby incorporated by reference in their entirety. 
         [0003]    The contents of commonly-assigned U.S. Patent Application No. 62/256,238, filed on Nov. 17, 2015, and titled “THIN OPTOELECTRONIC MODULES WITH APERTURES AND THEIR MANUFACTURE” are hereby incorporated by reference in their entirety. 
     
    
     FIELD OF THE TECHNOLOGY 
       [0004]    The present technology relates generally to optical devices and, more specifically, to packaging for optical devices and methods of manufacture. 
       BACKGROUND 
       [0005]    Optical devices that include one or more optical radiation emitters and one or more optical sensors can be used in a wide range of applications including, for example, distance measurement, proximity sensing, gesture sensing, and imaging. In some applications, such optoelectronic modules can be included in the housings of various consumer electronics, such as mobile computing devices, smart phones, or other devices. 
       SUMMARY 
       [0006]    Accordingly, there is a need for efficient and accurate optical devices and methods of manufacturing the same. In one aspect, there is an optical device. The optical device includes a substrate including a front surface. The optical device includes an optical emitter chip including a front surface and a rear surface, the rear surface of the optical emitter chip affixed to the front surface of the substrate. The optical device includes an optical sensor chip including a front surface and a rear surface, the rear surface of the optical sensor chip affixed to the front surface of the substrate, the optical sensor chip further including at least one main sensor and at least one reference sensor on the front surface of the optical sensor chip. The optical device includes an opaque dam disposed on the front surface of the optical sensor chip and at least a portion of the front face of the substrate, the dam separating the main optical sensor and the reference sensor. The optical device includes a first transparent encapsulation block encapsulating the optical emitter chip and the reference optical sensor. The optical device includes a second transparent encapsulation block encapsulating the main optical sensor. The optical device includes an opaque encapsulation material encapsulating the first transparent encapsulation block and the second transparent encapsulation block, the opaque encapsulation material including a first opening above the main optical sensor and a second opening above the optical emitter chip. The opaque encapsulation material extends between the first transparent encapsulation block and the second transparent encapsulation block and abuts the opaque dam. 
         [0007]    In some embodiments, the opaque dam further includes a channel into which the opaque encapsulation material extends. In some embodiments, the opaque encapsulation material further includes a channel into which the opaque dam extends. In some embodiments, the opaque dam is formed from a first opaque epoxy and the opaque encapsulation material is formed from a second opaque epoxy. In some embodiments, the first opaque epoxy has a first viscosity and the second opaque epoxy has a second viscosity, the second viscosity different from the first viscosity. 
         [0008]    In some embodiments, the optical device includes at least one trench formed in the substrate, wherein the opaque encapsulation material extends into the at least one trench. In some embodiments, a thickness of the opaque dam disposed over the substrate material is different than a second thickness of the opaque dam disposed over the optical sensor chip. In some embodiments, a first portion of the opaque dam disposed on the front surface of the optical sensor has a first thickness, and a second portion of the opaque dam disposed on at least a portion of the front face of the substrate has a second thickness, the first thickness being less than the second thickness. 
         [0009]    In another aspect, there is an optical device. The optical device includes a substrate including a front surface. The optical device includes an optical emitter chip including a front surface and a rear surface, the rear surface of the optical emitter chip affixed to the front surface of the substrate. The optical device includes an optical sensor chip including a front surface and a rear surface, the rear surface of the optical sensor chip affixed to the front surface of the substrate, the optical sensor chip further including at least one main sensor and at least one reference sensor on the front surface of the optical sensor chip. The optical device includes an opaque dam disposed on the front surface of the optical sensor chip and at least a portion of the front face of the substrate, the dam separating the main optical sensor and the reference sensor. The optical device includes a first transparent encapsulation block encapsulating the optical emitter chip and the reference optical sensor, the first transparent encapsulation block including a first passive optical element over the optical emitter chip. The optical device includes a second transparent encapsulation block encapsulating the main optical sensor, the second transparent encapsulation block including a second passive optical element over the main optical sensor. The optical device includes first opaque coating material disposed on the first transparent encapsulation block around the first passive optical element. The optical device includes second opaque coating material disposed on the second transparent encapsulation block around the second passive optical element. The optical device includes an opaque encapsulation material encapsulating the first transparent encapsulation block and the second transparent encapsulation block, the opaque encapsulation material including a first opening aligned with the first passive optical element and a second opening aligned with the second optical element. The opaque encapsulation material extends between the first transparent encapsulation block and the second transparent encapsulation block and abuts the opaque dam. 
         [0010]    In some embodiments, the opaque dam further includes a channel into which the opaque encapsulation material extends. In some embodiments, the opaque encapsulation material further includes a channel into which the opaque dam extends. In some embodiments, the opaque dam is formed from a first opaque epoxy and the opaque encapsulation material is formed from a second epoxy. In some embodiments, the first opaque epoxy has a first viscosity and the second opaque epoxy has a second viscosity, the second viscosity different from the first viscosity. In some embodiments, the optical device includes at least one trench formed in the substrate, wherein the opaque encapsulation material extends into the at least one trench. 
         [0011]    In some embodiments, a thickness of the opaque dam disposed over the substrate material is different than a second thickness of the opaque dam disposed over the optical sensor chip. In some embodiments, a first portion of the opaque dam disposed on the front surface of the optical sensor has a first thickness, and a second portion of the opaque dam disposed on at least a portion of the front face of the substrate has a second thickness, the first thickness being less than the second thickness. In some embodiments, the first passive optical element is a lens element, the second passive optical element is a lens element, or the first and second passive optical elements are lens elements. 
         [0012]    In another aspect, there is an optical device. The optical device includes a substrate including a front surface. The optical device includes an optical emitter chip including a front surface and a rear surface, the rear surface of the optical emitter chip affixed to the front surface of the substrate. The optical device includes an optical sensor chip including a front surface and a rear surface, the rear surface of the optical sensor chip affixed to the front surface of the substrate, the optical sensor chip further including at least one main sensor and at least one reference sensor on the front surface of the optical sensor chip. The optical device includes an opaque dam disposed on the front surface of the optical sensor chip and at least a portion of the front face of the substrate, the dam separating the main optical sensor and the reference sensor. The optical device includes a first transparent encapsulation block encapsulating the optical emitter chip and the reference optical sensor, the first transparent encapsulation block including a first passive optical element over the optical emitter chip. The optical device includes a second transparent encapsulation block encapsulating the main optical sensor, the second transparent encapsulation block including a second passive optical element over the main optical sensor. The optical device includes first opaque coating material disposed on the first transparent encapsulation block around the first passive optical element, the first opaque coating material covering substantially all of a top surface of the first transparent encapsulation block. The optical device includes second opaque coating material disposed on the second transparent encapsulation block around the second passive optical element, the second opaque coating material covering substantially all of a top surface of the second encapsulation block. The optical device includes an opaque encapsulation material encapsulating a plurality of side surfaces of the first transparent encapsulation block and encapsulating a plurality of side surfaces of the second transparent encapsulation block, wherein the opaque encapsulation material extends between the first transparent encapsulation block and the second transparent encapsulation block and abuts the opaque dam, and the opaque encapsulation material abuts the first opaque coating material along one or more edges between the top surface of the first transparent encapsulation block and the one or more side surfaces of the first transparent encapsulation block, and the opaque encapsulation material abuts the second opaque coating material along one or more edges between the top surface of the second transparent encapsulation block and the one or more side surfaces of the second transparent encapsulation block. 
         [0013]    In some embodiments, the opaque dam further includes a channel into which the opaque encapsulation material extends. In some embodiments, the opaque encapsulation material further includes a channel into which the opaque dam extends. In some embodiments, the opaque dam is formed from a first opaque epoxy and the opaque encapsulation material is formed from a second epoxy. In some embodiments, the first opaque epoxy has a first viscosity and the second opaque epoxy has a second viscosity, the second viscosity different from the first viscosity. In some embodiments, the optical device includes at least one trench formed in the substrate, wherein the opaque encapsulation material extends into the at least one trench. In some embodiments, a thickness of the opaque dam disposed over the substrate material is greater than a second thickness of the opaque dam disposed over the optical sensor chip. In some embodiments, first passive optical element is a lens element, the second passive optical element is a lens element, or the first and second passive optical elements are lens elements. 
         [0014]    Other aspects and advantages of the present technology will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating the principles of the technology by way of example only. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    The foregoing and other objects, features, and advantages of the present technology, as well as the technology itself, will be more fully understood from the following description of various embodiments, when read together with the accompanying drawings, in which: 
           [0016]      FIGS. 1-3  depict an optical device. 
           [0017]      FIGS. 4-6  depict an optical device. 
           [0018]      FIGS. 7-9  depict an optical device. 
           [0019]      FIGS. 10A-10F  illustrate a fabrication method for an optical device. 
           [0020]      FIGS. 11A-11F  illustrate a second fabrication method for an optical device. 
           [0021]      FIGS. 12A-12F  illustrate a third fabrication method for an optical device. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]      FIGS. 1-3  illustrate optical device  100 . As shown in  FIGS. 1-3 , exemplary optical device  100  includes substrate  105 . Substrate  105  can be, for example, a PCB chip. Optical sensor chip  110  is attached to the front surface of substrate  105  and can include main optical sensor  117  and reference optical sensor  122 . Optical emitter chip  125  is attached to the front surface of substrate  105 . Optical emitter chip  125  can be, for example, a light emitting diode (LED), infra-red (IR) LED, organic LED (OLED), infra-red (IR) laser, vertical cavity surface emitting laser (VCSEL), or other optical radiation source. Opaque dam  145  is disposed across optical device  100  on a front surface of optical sensor chip  110  and the front surface of substrate  105 . Opaque dam  145  can pass between and separate main optical sensor  117  and reference optical sensor  122 . 
         [0023]    Opaque dam  145  can be integrally formed and have varying thickness.  FIG. 3  illustrates a cross-sectional end view of optical device  100  and opaque dam  145  along line A-A in  FIG. 1B . For example, as shown in  FIG. 3 , the thickness of opaque dam  145  over substrate  105  is greater than the thickness of opaque dam  145  over optical sensor chip  110 . Opaque dam  145  can be substantially opaque to wavelengths of light emitted by optical emitter chip  125 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  125  from passing through opaque dam  145 . Opaque dam  145  can be made of, for example, an opaque epoxy. 
         [0024]    Integrated circuit chip  160  can be attached to the front surface of substrate  105 . Integrated circuit chip  160  can control emissions by optical emitter chip  125  and process information received from main optical sensor  117  and reference optical sensor  122 . In some embodiments, integrated circuit chip  160  can control optical emitter chip  125  and process information received from main optical sensor  117  and reference optical sensor  122  to detect proximity between optical device  100  and an outside object. 
         [0025]    Transparent encapsulation block  130  is disposed over and/or encapsulates optical emitter chip  125  and at least a portion of optical sensor chip  110 , including reference optical sensor  122 . Transparent encapsulation block  130  can be formed by, e.g., hardening or curing a liquid polymeric material or an epoxy. Transparent encapsulation block  130  can be transparent or translucent to at least particular wavelengths of light that are emitted by optical emitter chip  125 . Transparent encapsulation block  132  is disposed over and/or encapsulates at least a portion of optical sensor chip  110 , including main optical sensor  117 . Transparent encapsulation block  132  can be formed by, e.g., hardening or curing a liquid polymeric material or an epoxy. Transparent encapsulation block  132  can be transparent or translucent to at least particular wavelengths of light that are emitted by optical emitter chip  125 . In the illustrated embodiment, transparent encapsulation block  130  and transparent encapsulation block  132  are distinct from each other. 
         [0026]    Transparent encapsulation block  130  can include polished surface  165 , disposed above optical emitter chip  125 . Transparent encapsulation block  132  can include polished surface  167 , disposed over main optical sensor  117 . Polished surfaces  165  and  167  can have a surface roughness that is less than the surface roughness of other surfaces of transparent encapsulation block  130  and transparent encapsulation block  132 . Polished surfaces  165  and  167  can improve the performance of optical device  100 . For example, polished surfaces  165  and  167  can reduce the scattering of incident radiation. The roughness of the other surfaces of transparent encapsulation block  130  and transparent encapsulation block  132  can facilitate better adhesion between opaque encapsulation material  135  and the surfaces of transparent encapsulation block  130  and transparent encapsulation block  132 . 
         [0027]    In some embodiments, optical device  100  can include elements for spectral modification of radiation. In the illustrated embodiment, transparent chip  115  can be placed over main optical sensor  117 . Transparent chip  115  can be encapsulated in transparent encapsulation block  132 . Transparent chip  115  can filter radiation to facilitate controlling the wavelengths of radiation incident on main optical sensor  117 . For example, transparent chip  115  can be an infrared filter. In some embodiments, transparent chip  120  can be placed over reference optical sensor  122 . Transparent chip  120  can be encapsulated in transparent encapsulation block  130 . Transparent chip  120  can facilitate controlling the wavelengths of radiation incident on reference optical sensor  122 , as described above with respect to transparent chip  115 . In some embodiments, the optical device does not include transparent chips and spectral modification materials can be incorporated into other elements of the optical device. Spectral modification materials, e.g., filter and/or dye materials, can be included in one or more of the transparent encapsulation blocks. Spectral modification material can be sprayed, coated on, or otherwise applied to surfaces of the optical device, such as one or more surfaces of one or more of the transparent encapsulation blocks. 
         [0028]    Opaque encapsulation material  135  encapsulates transparent encapsulation block  130  and transparent encapsulation block  132 . Opaque encapsulation material  135  can form an outer layer of optical device  100 , for example by extending across the top of optical device  100  and the sides of optical device  100 . Opaque encapsulation material  135  includes first opening  150  disposed above main optical sensor  117  and second opening  155  disposed above optical emitter chip  125 . In the illustrated embodiment, opening  155  does not extend over reference optical sensor  122 . As shown in  FIGS. 2 and 3 , opaque encapsulation material  135  can extend beyond the front surface of substrate  105 . Trench  190  can be formed in substrate  105 , into which opaque encapsulation material  135  can extend. Opaque encapsulation material  135  can be, for example, an epoxy which is substantially opaque to wavelengths of light emitted by optical emitter chip  125 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  125  from passing through opaque encapsulation material  135 . 
         [0029]    Opaque encapsulation material  135  can include wall portion  140 . In the illustrated example, wall portion  140  is integrally formed in opaque encapsulation material  135 . Wall portion  140  can extend above and abut opaque dam  145 . Wall portion  140  of opaque encapsulation material  135  can be disposed between and/or divide transparent encapsulation block  130  and transparent encapsulation block  132 . In some embodiments, wall portion  140  has a width that is smaller than the width of opaque dam  145 . 
         [0030]    In some embodiments, improved optical isolation between optical emitter chip  125  and main optical sensor  117  can be facilitated by, e.g., interlocking wall portion  140  opaque dam  145 . In some embodiments, opaque dam  145  includes a channel disposed on a side opposite from the optical sensor chip  110 . The channel of opaque dam  145  can receive a portion of wall portion  140  extending therein. In some embodiments, wall portion  140  includes a channel (not shown) that can receive a portion of opaque dam  145 . 
         [0031]    In the illustrated embodiment, opaque dam  145  and opaque encapsulation material  135  are separately formed. In some embodiments, opaque dam  145  and opaque encapsulation material  135  can be formed from the same material, such as an epoxy, having the same viscosity. In some embodiments, opaque dam  145  can be formed from a material having a higher viscosity than opaque encapsulation material  135 . Use of a higher viscosity material for opaque dam  145  advantageously prevents the material from leaking on to sensitive portions of the optical sensor chip  110 , such as main optical sensor  117  and reference optical sensor  122 , during fabrication. 
         [0032]      FIGS. 4-6  depict optical device  400 . Optical device  400  includes substrate  405 . Substrate  405  can be, for example, a PCB chip. Optical sensor chip  410  is attached to the front surface of substrate  405  and can include main optical sensor  417  and reference optical sensor  422 . Optical emitter chip  425  is attached to the front surface of substrate  405 . Optical emitter chip  425  can be, for example, a light emitting diode (LED), infra-red (IR) LED, organic LED (OLED), infra-red (IR) laser, vertical cavity surface emitting laser (VCSEL), or other optical radiation source. Opaque dam  445  is disposed across optical device  400  on a front surface of optical sensor chip  410  and a front surface of substrate  405 . The opaque dam  445  can pass between and separate main optical sensor  417  and reference optical sensor  422 . 
         [0033]    Opaque dam  445  can be integrally formed and have varying thickness.  FIG. 6  illustrates a cross-sectional end view of optical device  400  and opaque dam  445  along line B-B of  FIG. 4B . For example, as shown in  FIG. 6 , the thickness of opaque dam  445  over substrate  405  is greater than the thickness of opaque dam  445  over optical sensor chip  410 . Opaque dam  445  can be substantially opaque to wavelengths of light emitted by optical emitter chip  425 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  425  from passing through opaque dam  445 . Opaque dam  445  can be made of, for example, an opaque epoxy. 
         [0034]    Integrated circuit chip  460  can be attached to the front surface of substrate  405 . Integrated circuit chip  460  can control emissions by optical emitter chip  425  and process information received from main optical sensor  417  and reference optical sensor  422 . In some embodiments, integrated circuit chip  460  can control optical emitter chip  425  and process information received from main optical sensor  417  and reference optical sensor  422  to detect proximity between optical device  400  and an outside object. 
         [0035]    Transparent encapsulation block  430  is disposed over and/or encapsulates optical emitter chip  425  and at least a portion of optical sensor chip  410 , including reference optical sensor  422 . Transparent encapsulation block  430  can be formed by, e.g., hardening or curing a liquid polymeric material or an epoxy. Transparent encapsulation block  430  can be transparent or translucent to at least particular wavelengths of light that are emitted by optical emitter chip  425 . Transparent encapsulation block  432  is disposed over and/or encapsulates at least a portion of optical sensor chip  410 , including main optical sensor  417 . Transparent encapsulation block  432  can be formed by, e.g., hardening or curing a liquid polymeric material or an epoxy. Transparent encapsulation block  432  can be transparent or translucent to at least particular wavelengths of light that are emitted by optical emitter chip  425 . In the illustrated embodiment, transparent encapsulation block  430  and transparent encapsulation block  432  are distinct from each other. 
         [0036]    In some embodiments, transparent chip  415  may be placed over main optical sensor  417 . Transparent chip  415  can be encapsulated in transparent encapsulation block  432 . Transparent chip  415  can filter radiation to facilitate controlling the wavelengths of radiation incident on main optical sensor  417 . For example, transparent chip  415  can be an infrared filter. In some embodiments, transparent chip  420  can be placed over reference optical sensor  422 . Transparent chip  420  can be encapsulated in transparent encapsulation block  430 . Transparent chip  420  can facilitate controlling wavelengths of radiation incident on reference optical sensor  422  as described above with respect to transparent chip  415 . 
         [0037]    In other embodiments, transparent encapsulation blocks  430  and/or  432  can include passive optical elements. Passive optical elements can be integral with or distinct from transparent encapsulation blocks  430  or  432 . Passive optical elements can be formed from the same material as transparent encapsulation blocks  430  or  432 . For example, passive optical elements can be lens elements. As depicted in  FIGS. 4-6 , lens elements  470  and/or  475  can be disposed opposite from substrate  405 . Lens elements  470  and/or  475  can be configured to modify a property of light entering or exiting optical device  400 , including, for instance, by refraction, diffraction, or by partially refracting and diffracting light. Lens elements can be associated with particular elements of optical device  400 . As illustrated in, for example,  FIG. 5 , lens element  470  can be disposed above main optical sensor  417 . Lens element  475  can be configured to modify a property of light passing through lens element  470 . Lens element  475  can be disposed above optical emitter chip  425 . Lens element  475  can be configured to modify a property of light passing through lens element  475  in the same or a different manner than the modification performed by lens element  470 . 
         [0038]    As shown in  FIGS. 4A and 5 , opaque coating  480  can be applied to a surface of transparent encapsulation block  430  (e.g., in an annular shape around lens element  475 ). Opaque coating  480  can define opening  452 . For example, opaque coating  480  can form an apron around passive optical elements on the surface of transparent encapsulation block  430 . Opaque coating  482  can be applied to a surface of transparent encapsulation block  432  (e.g., in an annular shape around lens element  470 ). Opaque coating  482  can define an opening  457 . For example, opaque coating  482  can form an apron around passive optical elements on the surface of transparent encapsulation block  432 . Opaque coating  480  and opaque coating  482  can be substantially opaque to wavelengths of light emitted by optical emitter chip  425 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  425  from passing through opaque coating  480  or opaque coating  482 . Opaque coating  480  and opaque coating  482  can be substantially opaque to wavelengths of light detectable by main optical sensor  417  or reference optical sensor  422 . Opaque coating  480  and opaque coating  482  can be constructed using, for example, a photostructurable material such as, e.g., a resist or photoresist material. Opaque coating  480  and  482  can be applied with high accuracy to facilitate accurate construction of optical device  400 . For example, the application of opaque coating  480  and opaque coating  482  can be controlled to prevent undesired contamination of passive optical elements of optical device  400 . 
         [0039]    Opaque encapsulation material  435  encapsulates transparent encapsulation block  430  and transparent encapsulation block  432 . Opaque encapsulation material  435  can form an outer layer of optical device  400 , for example by extending across the top of optical device  400  and the sides of optical device  400 . Opaque encapsulation material  435  includes first opening  450  disposed above opening  452  and main optical sensor  417 . Opaque encapsulation material  435  includes second opening  455  disposed above opening  457  and optical emitter chip  425 . In the illustrated embodiment, opening  455  does not extend over reference optical sensor  422 . As shown in  FIGS. 5 and 6 , opaque encapsulation material  435  can extend beyond a front surface of substrate  405 . Trench  490  can be formed in substrate  405  into which opaque encapsulation material  435  can extend. Opaque encapsulation material  435  can be, for example, an epoxy which is substantially opaque to wavelengths of light emitted by optical emitter chip  425 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  425  from passing through opaque encapsulation material  435 . In some embodiments, the optical device does not include transparent chips and spectral modification materials can be incorporated into other elements of the optical device. Spectral modification materials, e.g., filter and/or dye materials, can be included in one or more of the transparent encapsulation blocks. Spectral modification material can be sprayed, coated on, or otherwise applied to surfaces of the optical device, such as one or more surfaces of one or more of the transparent encapsulation blocks. 
         [0040]    In some embodiments, opaque encapsulation material  435  at least partially encapsulates opaque coating  480  or opaque coating  482 . Opaque encapsulation material  435  can be disposed on a top surface of opaque coating  480  which is opposite from the surface of opaque coating  480  disposed on the surface of transparent encapsulation block  430 . Opaque encapsulation material  435  can be partially disposed on a top surface of opaque coating  482  which is opposite from the surface of opaque coating  482  disposed on the surface of transparent encapsulation block  432 . Opaque encapsulation material  435  can at least partially overlap opaque coating  480  or opaque coating  482 . 
         [0041]    Opaque encapsulation material  435  can include wall portion  440 . In the illustrated example, wall portion  440  is integrally formed in opaque encapsulation material  435 . Wall portion  440  can extend above and abut opaque dam  445 . Wall portion  440  of opaque encapsulation material  435  can be disposed between and/or divide transparent encapsulation block  430  and transparent encapsulation block  432 . In some embodiments, wall portion  440  has a width that is smaller than the width of opaque dam  445 . 
         [0042]    In some embodiments, improved optical isolation between optical emitter chip  425  and main optical sensor  417  can be facilitated by, e.g., interlocking wall portion  440  opaque dam  445 . In some embodiments, opaque dam  445  includes a channel disposed on a side opposite from the optical sensor chip  410 . The channel of opaque dam  445  can receive a portion of wall portion  440  extending therein. In some embodiments, wall portion  440  includes a channel (not shown) that can receive a portion of opaque dam  445 . 
         [0043]    In the illustrated embodiment, opaque dam  445  and opaque encapsulation material  435  are separately formed. In some embodiments, opaque dam  445  and opaque encapsulation material  435  can be formed from the same material, such as an epoxy, having the same viscosity. In some embodiments, opaque dam  445  can be formed from a material having a higher viscosity than opaque encapsulation material  435 . Use of a higher viscosity material for opaque dam  445  advantageously prevents the material from leaking on to sensitive portions of optical sensor chip  410 , such as main optical sensor  417  and reference optical sensor  422 , during fabrication. 
         [0044]      FIGS. 7-9  depict an optical device. Optical device  700  can include substrate  705 . Substrate  705  can be, for example, a PCB chip. Optical sensor chip  710  is attached to the front surface of substrate  705  and can include main optical sensor  717  and reference optical sensor  722 . Optical emitter chip  725  is attached to a front surface of substrate  705 . Optical emitter chip  725  can be, for example, a light emitting diode (LED), infra-red (IR) LED, organic LED (OLED), infra-red (IR) laser, vertical cavity surface emitting laser (VCSEL), or other optical radiation source. Opaque dam  745  is disposed across optical device  700  on a front surface of optical sensor chip  710  and a front surface of substrate  705 . Opaque dam  745  can pass between and separate main optical sensor  717  and reference optical sensor  722 . 
         [0045]    Opaque dam  745  can be integrally formed and have varying thickness.  FIG. 9  illustrates a cross-sectional end view of optical device  700  and opaque dam  745  along line C-C of  FIG. 7B . For example, as shown in  FIG. 9 , the thickness of opaque dam  745  over substrate  705  is greater than the thickness of opaque dam  745  over optical sensor chip  710 . Opaque dam  745  can be substantially opaque to wavelengths of light emitted by optical emitter chip  725 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  725  from passing through opaque dam  745 . Opaque dam  745  can be made of, for example, an opaque epoxy. 
         [0046]    Integrated circuit chip  760  can be attached to the front surface of substrate  705 . Integrated circuit chip  760  can control emissions by optical emitter chip  725  and process information received from main optical sensor  717  and reference optical sensor  722 . In some embodiments, integrated circuit chip  760  can control optical emitter chip  725  and process information received from main optical sensor  717  and reference optical sensor  722  to detect proximity between optical device  700  and an outside object. 
         [0047]    Transparent encapsulation block  730  is disposed over and/or encapsulates optical emitter chip  725  and at least a portion of optical sensor chip  710 , including reference optical sensor  722 . Transparent encapsulation block  730  can be formed by, e.g., hardening or curing a liquid polymeric material or an epoxy. Transparent encapsulation block  730  can be transparent or translucent to at least particular wavelengths of light that are emitted by optical emitter chip  725 . Transparent encapsulation block  732  is disposed over and/or encapsulates at least a portion of optical sensor chip  710 , including main optical sensor  117 . Transparent encapsulation block  732  can be formed by, e.g., hardening or curing a liquid polymeric material or an epoxy. Transparent encapsulation block  732  can be transparent or translucent to at least particular wavelengths of light that are emitted by optical emitter chip  725 . In the illustrated embodiment, transparent encapsulation block  730  and transparent encapsulation block  732  are distinct from each other. 
         [0048]    In some embodiments, transparent chip  715  may be placed over main optical sensor  717 . Transparent chip  715  can be encapsulated in transparent encapsulation block  732 . Transparent chip  715  can filter radiation to facilitate controlling the wavelengths of radiation incident on main optical sensor  717 . For example, transparent chip  715  can be an infrared filter. In some embodiments, transparent chip  720  can be placed over reference optical sensor  722 . Transparent chip  720  can be encapsulated in transparent encapsulation block  730 . Transparent chip  720  can facilitate controlling wavelengths of radiation incident on reference optical sensor  722  as described above with respect to transparent chip  715 . In some embodiments, the optical device does not include transparent chips and spectral modification materials can be incorporated into other elements of the optical device. Spectral modification materials, e.g., filter and/or dye materials, can be included in one or more of the transparent encapsulation blocks. Spectral modification material can be sprayed, coated on, or otherwise applied to surfaces of the optical device, such as one or more surfaces of one or more of the transparent encapsulation blocks. 
         [0049]    Transparent encapsulation block  730  can include passive optical elements. Passive optical elements can be integral with or distinct from transparent encapsulation materials  730  or  732 . For example, passive optical elements can be lens elements  770  and  775 . Lens element  770  can be disposed above main optical sensor  717 . Lens element  775  can be disposed above optical emitter chip  725 . Other characteristics of lens elements  770  and  775  can be similar to those discussed for lens elements  470  and  475  in  FIGS. 4-6 . 
         [0050]    Opaque coating  780  can be disposed on the surface of transparent encapsulation block  730 . Opaque coating  782  can be disposed on the surface of transparent encapsulation block  732 . Opaque coating  780  and opaque coating  782  are substantially opaque to wavelengths of light emitted by optical emitter chip  725 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  725  from passing through opaque coating  780  and/or opaque coating  782 . Opaque coating  780  and/or opaque coating  782  can be substantially opaque to wavelengths of light detectable by main optical sensor  717  or reference optical sensor  722 . Opaque coating  780  or  782  can be constructed using, for example, a photostructurable material such as, e.g., a resist or photoresist material. Opaque coating  780  and opaque coating  782  can be applied with high accuracy to facilitate accurate construction of optical device  700 . For example, the application of opaque coating  780  and opaque coating  782  can be controlled to prevent undesired contamination of passive optical elements of optical device  700 . 
         [0051]    As depicted in  FIG. 8 , opaque encapsulation material  735  can be disposed on the sides of optical device  700 . Opaque encapsulation material  735  can be configured to optically isolate transparent encapsulation block  730  and transparent encapsulation block  732  on at least one side from wavelengths of light that are detectable by, for example, main optical sensor  717 . Opaque encapsulation material  735  can be, for example, an epoxy which is substantially opaque to wavelengths of light emitted by optical emitter chip  725 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  725  from passing through opaque encapsulation material  735 . 
         [0052]    Opaque encapsulation material  735  can encapsulate a plurality of side surfaces of transparent encapsulation block  730  and can encapsulate a plurality of side surfaces of transparent encapsulation block  732 . In some embodiments, opaque encapsulation material can encapsulate a plurality of side surfaces of transparent block  730  and can encapsulate a plurality of side surfaces of transparent encapsulation block  732 . 
         [0053]    In some embodiments, opaque encapsulation material  735  can include wall portion  740 . Wall portion  740  can extend above and abut opaque dam  745 . Wall portion  740  can be disposed between and or divide transparent encapsulation block  730  and transparent encapsulation block  732 . In some embodiments, wall portion  740  has a width that is smaller than the width of opaque dam  745 . 
         [0054]    In some embodiments, opaque encapsulation material  735  can be in contact with opaque coating  780  and/or opaque coating  782  to facilitate light tightness. In some embodiments, opaque encapsulation material  735  abuts opaque coating  780  along one or more edges between the top surface of transparent encapsulation block  730  and the one or more side surfaces of transparent encapsulation block  730 . In some embodiments, opaque encapsulation material  735  and/or wall portion  740  abut opaque coating  782  along one or more edges between the top surface of transparent encapsulation block  732  and the one or more side surfaces of transparent encapsulation block  732 . 
         [0055]    In some embodiments, improved optical isolation between optical emitter chip  725  and main optical sensor  717  can be facilitated by, e.g., interlocking wall portion  740  opaque dam  745 . In some embodiments, opaque dam  745  includes a channel disposed on a side opposite from the optical sensor chip  710 . The channel of opaque dam  745  can receive a portion of wall portion  740  extending therein. In some embodiments, wall portion  740  includes a channel (not shown) that can receive a portion of opaque dam  745 . 
         [0056]    In the illustrated embodiment, opaque dam  745  and opaque encapsulation material  735  are separately formed. In some embodiments, opaque dam  745  and wall portion  740  can be formed from the same material, such as an epoxy, having the same viscosity. In some embodiments, opaque dam  745  can be formed from a material having a higher viscosity than wall portion  740 . Use of a higher viscosity material for opaque dam  745  advantageously prevents the material from leaking on to sensitive portions of optical sensor chip  710 , such as main optical sensor  717  and reference optical sensor  722 , during fabrication. 
         [0057]    The optical modules described above can be fabricated by various techniques, examples of which are described below. 
         [0058]      FIGS. 10A-10F  illustrate a fabrication method for an optical device. As shown in  FIG. 10A , a plurality of optical components are provided on the front surface of substrate  1005 . In some methods, optical sensor chip  1010 , integrated circuit chip  1060 , and optical emitter chip  1025  can be provided on the front surface of substrate  1005 . 
         [0059]    Opaque dam  1045  is dispensed on the front surface of optical sensor chip  1010  substrate  1005 , passing between and separating main optical sensor  1017  and reference optical sensor  1022 . In some methods, opaque dam  1045  is dispensed using an applicator such as, e.g., a syringe. The thickness of opaque dam  1045  over substrate  1005  is greater than the thickness of opaque dam  1045  over optical sensor chip  1010 . According to some methods, the thickness of opaque dam  1045  can be controlled during fabrication by controlling the rate of application of the dam material. According to some methods, the thickness of opaque dam  1045  can be controlled by slowing or stopping the applicator over a particular region, for example, substrate  1005 , such that an increased volume of opaque dam material is deposited. Opaque dam  1045  can be made of, for example, an opaque epoxy. Opaque dam  1045  can then be hardened or cured. Curing can be accomplished, for example, by applying energy to the material, e.g., in the form of heat and/or radiation. 
         [0060]    Transparent encapsulation material  1028  is dispensed over the front surface of  1005  and optical components thereon. As depicted in  FIG. 10C , transparent encapsulation material  1028  encapsulates exposed portions of substrate  1005 , optical sensor chip  1010 , opaque dam  1045 , integrated circuit chip  1060 , and optical emitter  1025 . Prior to the application of transparent encapsulation material  1028 , transparent chips, such as, e.g. the components associated with reference numerals  115  and  120  in  FIG. 1 , can be optionally placed on top of main optical sensor  1017  and/or reference optical sensor  1022 . Transparent encapsulation material  1028  can be, e.g., a liquid polymeric material or an epoxy, which is transparent or translucent to at least particular wavelengths of light that are emitted by optical emitter chip  1025 . Transparent encapsulation material  1028  can be cured, for example, by applying energy to the material, e.g., in the form of heat and/or radiation. 
         [0061]    As depicted in  FIG. 10D , portions of cured transparent encapsulation material  1028  are removed, forming grooves. Removal of portions of transparent encapsulation material  1028  can be accomplished, for instance, by a dicing process, using, e.g., a dicing saw. The dimensions of the portions of cured transparent encapsulation material  1028  removed can be controlled, for example, by adjusting the depth by which blades of the dicing saw cut, or adjusting the width of the saw blade. According to some methods, dicing can remove a portion of substrate  1005 , forming a trench  1090 . Dicing can also remove a portion of opaque dam  1045 , creating a channel disposed in opaque dam  1045  on a side opposite from optical sensor chip  1010 . Dicing should not cut through opaque dam  1045 , because damage to optical sensor chip  1010  would result. In this manner, opaque dam  1045  can act as a protective layer over optical sensor chip  1010  during the dicing process. The dicing process can define transparent encapsulation block  1030  and transparent encapsulation block  1032 , with grooves disposed between. 
         [0062]    Opaque encapsulation material  1035  is applied to outer surfaces of transparent encapsulation block  1030  and transparent encapsulation block  1032 . Opaque encapsulation material  1035  can form an outer layer on the surface of transparent encapsulation block  1030  and transparent encapsulation block  1032 . During application, opaque encapsulation material  1035  fills the grooves between transparent encapsulation block  1030  and transparent encapsulation block  1032  formed during the dicing process. According to some methods, where the dicing process has formed a channel in opaque dam  1045 , opaque encapsulation material  1035  extends into and fills the channel. In this manner, a light tight barrier can be formed between transparent encapsulation block  1030  and transparent encapsulation block  1032 . In some methods, where the dicing process has formed trench  1090  in substrate  1005 , opaque encapsulation material  1035  substantially fills trench  1090 , facilitating a light tight interface. Opaque encapsulation material  1035  can be, for example, an epoxy which is substantially opaque to wavelengths of light emitted by optical emitter chip  1025 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  1025  from passing through opaque encapsulation material  1035 . 
         [0063]    According to  FIG. 10F , substrate  1005  can be singulated to produce singulated optical device  1000 . Singulation can be accomplished by means of dicing, e.g., using a dicing saw. In some methods, singulation can be accomplished by, e.g., laser cutting. Singulation can be accomplished by dicing completely through substrate  1005  and the portion of opaque encapsulation material  1035  disposed above and abutting substrate  1005 . 
         [0064]    A second fabrication method for an optical device is illustrated in  FIGS. 11A-11F . As shown in  FIG. 11A , a plurality of optical components are provided on the front surface of substrate  1105 . In some methods, optical sensor chip  1110 , integrated circuit chip  1160 , and optical emitter chip  1125  can be provided on the front surface of substrate  1105 . 
         [0065]    Opaque dam  1145  is dispensed on the front surface of optical sensor chip  1110  and substrate  1105 , passing between and separating main optical sensor  1117  and reference optical sensor  1122 . In some methods, opaque dam  1145  is dispensed using an applicator such as, e.g., a syringe. The thickness of opaque dam  1145  over substrate  1105  is greater than the thickness of opaque dam  1145  over optical sensor chip  1110 . According to some methods, the thickness of opaque dam  1145  can be controlled by controlling the rate of application of the dam material. According to some methods, the thickness of opaque dam  1145  can be controlled by slowing or stopping the applicator over a particular region, for example, substrate  1105 , such that an increased volume of opaque dam material is deposited. Opaque dam  1145  can be made of, for example, an opaque epoxy. Opaque dam  1145  can then be hardened or cured. Curing can be accomplished, for example, by applying energy to the material, e.g., in the form of heat and/or radiation. 
         [0066]    Transparent encapsulation material  1128  is dispensed over the front surface of  1105  and optical components thereon. As depicted in  FIG. 11C , transparent encapsulation encapsulates exposed portions of substrate  1105 , optical sensor chip  1110 , opaque dam  1145 , integrated circuit chip  1160 , an optical emitter  1125 . Prior to the application of transparent encapsulation material, transparent chips, such as, e.g. the components associated with reference numerals  415  and  420  in  FIG. 4 , may be placed on top of main optical sensor  1117  and/or reference optical sensor  1122 . Transparent encapsulation material  1128  can be, e.g., a liquid polymeric material or an epoxy, which is transparent or translucent to at least particular wavelengths of light that are emitted by optical emitter chip  1125 . Passive optical elements may be integrally or non-integrally formed from transparent encapsulation material  1128 . For example, passive optical elements can be lens elements  1170  and/or  1175 . In some methods, lens elements  1170  and/or  1175  can be shaped by means of a replication tool such as, e.g., by a mold. Transparent encapsulation material  1128  can be cured, for example, by applying energy to the material, e.g., in the form of heat and/or radiation. 
         [0067]    Opaque coatings  1180  and  1182  are applied to the surfaces of transparent encapsulation material  1128 . According to some embodiments, opaque coating  1180  and  1182  can be applied such that opaque coating  1180  forms an apron around lens element  1170 . Opaque coating  1182  can be applied to form an apron around lens element  1175 . Opaque coating material  1180  and/or  1182  can be a photostructurable material such as, e.g., a resist or photoresist material that is substantially opaque to wavelengths of light emitted by optical emitter chip  1125 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  1125  from passing through opaque coating  1180  or  1182 . Opaque coating  1180  and  1182  can be applied by various methods, including, e.g. spray coating or spin coating. The methods used to apply opaque coatings  1180  and  1182  can be very precise and advantageously increase accurate construction. After application, opaque coating  1180  and  1182  can be developed using, for example, selective illumination means such as laser direct imaging (LDI) or using a mask. 
         [0068]    As depicted in  FIG. 11E , portions of cured transparent encapsulation material  1128  are removed, forming grooves. Removal of portions of transparent encapsulation material  1128  can be accomplished, for instance, by a dicing process, using, e.g., a dicing saw. The dimensions of the portions of cured transparent encapsulation material  1128  removed can be controlled, for example, by adjusting the depth by which blades of the dicing saw cut, or adjusting the width of the saw blade. According to some methods, dicing can remove a portion of substrate  1105 , forming trench  1190 . Dicing can also remove a portion of opaque dam  1145 , creating a channel disposed in opaque dam  1145  on a side opposite from optical sensor chip  1110 . Dicing should not cut through opaque dam  1145 , because damage to optical sensor chip  1110  would result. In this manner, opaque dam  1145  can act as a protective layer over optical sensor chip  1110  during the dicing process. The dicing process can define transparent encapsulation block  1130  and transparent encapsulation block  1132 , with grooves between the blocks. 
         [0069]    Opaque encapsulation material  1135  is applied to outer surfaces of transparent encapsulation block  1130  and transparent encapsulation block  1132 . Opaque encapsulation material  1135  can be dispensed across the top and on the sides of transparent encapsulation block  1130  and transparent encapsulation block  1132 . During application, opaque encapsulation material  1135  fills the grooves between transparent encapsulation block  1130  and transparent encapsulation block  1132  formed during the dicing process. According to some methods, where the dicing process has formed a channel in opaque dam  1145 , opaque encapsulation material  1135  extends into and fills the channel. In this manner, a light tight barrier can be formed between transparent encapsulation block  1130  and transparent encapsulation block  1132 . In some methods, where the dicing process has formed trench  1190  in substrate  1105 , opaque encapsulation material  1135  substantially fills trench  1190 , facilitating a light tight interface. Opaque encapsulation material  1135  can be, for example, an epoxy which is substantially opaque to wavelengths of light emitted by optical emitter chip  1125 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  1125  from passing through opaque encapsulation material  1135 . 
         [0070]    According to some embodiments, opaque encapsulation material  1135  can be applied to an outer surface of at least a part of opaque coating  1180  or  1182 . Opaque encapsulation material  1135  can be applied to encapsulate at least a portion of opaque coating  1180  or  1182 . In some embodiments, opaque encapsulation material can at least partially overlap opaque coating  1180  or  1182 . 
         [0071]    In another step, substrate  1105  can be singulated according to the method described with reference to  FIG. 10F . 
         [0072]      FIGS. 12A-12F  illustrate a third fabrication method for an optical device. As shown in  FIG. 12A , a plurality of optical components are provided on the front surface of substrate  1205 . In some methods, optical sensor chip  1210 , integrated circuit chip  1260 , and optical emitter chip  1225  can be provided on the front surface of substrate  1205 . 
         [0073]    Opaque dam  1245  is dispensed on the front surface of optical sensor chip  1210  substrate  1205 , passing between and separating main optical sensor  1217  and reference optical sensor  1222 . In some methods, opaque dam  1245  is dispensed using an applicator such as, e.g., a syringe. The thickness of opaque dam  1245  over substrate  1205  is greater than the thickness of opaque dam  1245  over optical sensor chip  1210 . According to some methods, the thickness of opaque dam  1245  can be controlled by controlling the rate of application of the dam material. According to some methods, the thickness of opaque dam  1245  can be controlled by slowing or stopping the applicator over a particular region, for example, substrate  1205 , such that an increased volume of opaque dam material is deposited. Opaque dam  1245  can be made of, for example, an opaque epoxy. Opaque dam  1245  can then be hardened or cured. Curing can be accomplished, for example, by applying energy to the material, e.g., in the form of heat and/or radiation. 
         [0074]    Transparent encapsulation material  1228  is dispensed over the front surface of  1205  and optical components thereon. As depicted in  FIG. 12C , transparent encapsulation encapsulates exposed portions of substrate  1205 , optical sensor chip  1210 , opaque dam  1245 , integrated circuit chip  1260 , an optical emitter  1225 . Prior to the application of transparent encapsulation material, transparent chips, such as, e.g. the components associated with reference numerals  715  and  720  in  FIG. 7 , may be placed on top of main optical sensor  1217  and/or reference optical sensor  1222 . Transparent encapsulation material  1228  can be, e.g., a liquid polymeric material or an epoxy, which is transparent or translucent to at least particular wavelengths of light that are emitted by optical emitter chip  1225 . Passive optical elements may be integrally or non-integrally formed from transparent encapsulation material  1228 . For example, passive optical elements can be lens elements  1270  and/or  1275 . In some methods, lens elements  1270  and/or  1275  can be shaped by means of a replication tool such as, e.g., by a mold. Transparent encapsulation material  1228  can be cured, for example, by applying energy to the material, e.g., in the form of heat and/or radiation. 
         [0075]    Opaque coating  1280  and  1282  is applied to the surface of transparent encapsulation material  1228 . Opaque coating  1280  and  1282  defines openings or apertures  1250  and  1255 . Openings or apertures  1250  and  1255  in opaque coating  1280  and  1282  can be associated with passive optical elements, such as, for example, lens elements  1270  and/or  1275 . Openings or apertures  1250  and  1255  in opaque coating  1280  and  1282  can be associated with particular elements of the optical device. According to one method, opaque coating  1280  and  1282  can be applied such that opaque coating  1280  forms an apron around lens element  1270 . Opaque coating  1282  can be applied to substantially the entire top surface of transparent encapsulation blocks  1230  and  1232  other than apertures or openings  1250  and  1250 . Opaque coating material  1280  and/or  1282  can be a photostructurable material such as, e.g., a resist or photoresist material that is substantially opaque to wavelengths of light emitted by optical emitter chip  1225 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  1225  from passing through opaque coating  1280  or  1282 . Opaque coating  1280  and  1282  can be applied by various methods, including, e.g. spray coating or spin coating. The methods used to apply opaque coatings  1280  and  1282  can be very precise and advantageously increase accurate construction. After application, opaque coating  1280  and  1282  can be developed using, for example, selective illumination means such as laser direct imaging (LDI) or using a mask. 
         [0076]    As depicted in  FIG. 12E , portions of cured transparent encapsulation material  1228  are removed, forming grooves. Removal of portions of transparent encapsulation material  1228  can be accomplished, for instance, by a dicing process, using, e.g., a dicing saw. The dimensions of the portions of cured transparent encapsulation material  1228  removed can be controlled, for example, by adjusting the depth by which blades of the dicing saw cut, or adjusting the width of the saw blade. According to some methods, dicing can remove a portion of substrate  1205 , forming trench  1290 . Dicing can also remove a portion of opaque dam  1245 , creating a channel disposed in opaque dam  1245  on a side opposite from the optical sensor chip  1210 . Dicing should not cut through opaque dam  1245 , because damage to optical sensor chip  1210  would result. In this manner, opaque dam  1245  can act as a protective layer over optical sensor chip  1210  during the dicing process. The dicing process can define transparent encapsulation block  1230  and transparent encapsulation block  1232 , with grooves between the blocks. 
         [0077]    Opaque encapsulation material  1235  is applied on the sides of transparent encapsulation blocks  1230  and  1232 . Opaque encapsulation material  1235  can be applied so as to encapsulate a plurality of side surface of transparent encapsulation block  1230  and a plurality of side surfaces of transparent encapsulation block  1232 . During application, opaque encapsulation material  1235  fills the grooves between transparent encapsulation block  1230  and transparent encapsulation block  1232  formed during the dicing process. According to some methods, where the dicing process has formed a channel in opaque dam  1245 , opaque encapsulation material  1235  extends into and fills the channel. In this manner, a light tight barrier can be formed between transparent encapsulation block  1230  and transparent encapsulation block  1232 . In some methods, where the dicing process has formed trench  1290  in substrate  1205 , opaque encapsulation material  1235  substantially fills trench  1290 , facilitating a light tight interface. Opaque encapsulation material  1235  can be, for example, an epoxy which is substantially opaque to wavelengths of light emitted by optical emitter chip  1225 , in order to at least substantially interfere with or prevent light emitted from optical emitter chip  1225  from passing through opaque encapsulation material  1235 . According to certain methods, opaque encapsulation material  1235  can be in contact with opaque coating  1280  or  1282  to facilitate optical light tightness where opaque encapsulation material  1235  is in contact with opaque coating  1280 . In some methods, opaque encapsulation material  1235  abuts opaque coating  1280  along one or more edges between the top surface of transparent encapsulation block  1230  and the one or more side surfaces of transparent encapsulation block  1230 . According to some methods, opaque encapsulation material  1235  abuts opaque coating  1282  along one or more edges between the top surface of transparent encapsulation block  1232  and the one or more side surfaces of transparent encapsulation block  1232 . 
         [0078]    In another step, substrate  1205  can be singulated according to the method described with reference to  FIG. 10F .