Patent Publication Number: US-2021183839-A1

Title: Semiconductor package device and method of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 15/643,458 filed Jul. 6, 2017, which claims the benefit of and priority to U.S. Provisional Application No. 62/363,102, filed Jul. 15, 2016, the contents of which are incorporated herein by reference in their entirety. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a semiconductor package device, and to a semiconductor package device including one or more light emitting components. 
     2. Description of the Related Art 
     In an optical sensor module, an alignment of an aperture or a housing of a lid and a light emitter or a light detector can affect performance of the sensor module. However, offsets from a desired position may occur during manufacture of the optical sensor module. For example, an offset (e.g. shift) of a die relative to a mounting area of a carrier (an area where the die is mounted or placed) can be approximately in a range of 25 μm to 50 μm, an offset of a panel of a lid or housing relative to the carrier can be approximately 100 μm, and an offset of an aperture of the lid can be approximately 30 μm. Even if the panel of the lid is divided into individual lids, one or more shifts of approximately 50 μm may occur when assembling the die and the individual lid. It can be desirable to reduce such offsets (e.g. offsets generated during the manufacture of the optical sensor module). 
     In addition, a size of an opening (e.g. an opening through which light passes) of the lid or housing (defined by the lid or housing) is important for some optical positioning applications (e.g., proximity sensor) to accurately measure a distance between an object and the optical sensor module. An accuracy of the measurement result can improve as the size of the opening of the lid or housing decreases. However, a minimum size of the opening of the lid achievable for some comparative techniques is approximately 250 μm. Therefore, it can be desirable to develop an optical sensor module having a lid or housing with a small opening (e.g. an opening smaller than approximately 250 μm). 
     SUMMARY 
     In accordance with an aspect of the present disclosure, an optical module includes a carrier, a light emitter disposed on the carrier, a light detector disposed on the carrier, and a housing disposed on the carrier. The housing defines a first opening that exposes the light emitter and a second opening that exposes the light detector. The optical module further includes a first light transmission element disposed on the first opening and a second light transmission element disposed on the second opening. A first opaque layer is disposed on the first light transmission element, the first opaque layer defining a first aperture, and a second opaque layer disposed on the second light transmission element, the second opaque layer defining a second aperture. 
     In accordance another aspect of the present disclosure, a method of manufacturing an optical module includes providing a carrier, placing a light emitter on the carrier, placing a light detector on the carrier, and placing a housing on the carrier, the housing defining a first opening that exposes the light emitter and a second opening that exposes the light detector. The method further includes placing a first light transmission element on the first opening, the first light transmission element including a first opaque layer that defines a first aperture, and placing a second light transmission element on the second opening, the second light transmission element including a second opaque layer that defines a second aperture. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a cross-sectional view of some embodiments of an optical device in accordance with a first aspect of the present disclosure; 
         FIG. 2  illustrates a cross-sectional view of some embodiments of an optical device in accordance with the first aspect of the present disclosure; 
         FIG. 3A  illustrates a cross-sectional view of some embodiments of a semiconductor device in accordance with a second aspect of the present disclosure; 
         FIG. 3B  illustrates a cross-sectional view of some embodiments of a semiconductor device in accordance with the second aspect of the present disclosure; and 
         FIG. 4A ,  FIG. 4B  and  FIG. 4C  illustrate a method for manufacturing an optical device in accordance with some embodiments of the present disclosure. 
     
    
    
     Common reference numerals are used throughout the drawings and the detailed description to indicate the same or similar components. The present disclosure can be best understood from the following detailed description taken in conjunction with the accompanying drawings. 
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a cross-sectional view of some embodiments of an optical device  1  in accordance with a first aspect of the present disclosure. The optical device  1  includes a carrier  10 , a first electronic component  11 , a second electronic component  12 , a first light transmission element  13 , a second light transmission element  14 , a lid  15 , a first opaque layer  16  and a second opaque layer  17 . 
     The carrier  10  may include, for example, a printed circuit board, such as a paper-based copper foil laminate, a composite copper foil laminate, or a polymer-impregnated glass-fiber-based copper foil laminate. The carrier  10  may include an interconnection structure, such as a plurality of conductive traces or a through via. In some embodiments, the carrier  10  includes a ceramic material or a metal plate. In some embodiments, the carrier  10  may include a substrate, such as an organic substrate or a leadframe. In some embodiments, the carrier  10  may include a two-layer substrate which includes a core layer and a conductive material and/or structure disposed on an upper surface and a bottom surface of the carrier  10 . The conductive material and/or structure may include a plurality of traces. 
     The first electronic component  11  is disposed on the carrier  10 . The first electronic component  11  may include an emitting die or other optical die. For example, the first electronic component  11  may include a light-emitting diode (LED), a laser diode, or another device that may include one or more semiconductor layers. The semiconductor layers may include silicon, silicon carbide, gallium nitride, or any other semiconductor materials. The first electronic component  11  can be connected to the carrier  10  by way of flip-chip or wire-bond techniques, for example. In some embodiments, the first electronic component  11  includes an LED die bonded on the carrier  10  via a die bonding material. The LED die includes at least one wire-bonding pad. The LED die is electrically connected to the carrier  10  by a conductive wire, one end of which is bonded to the wire-bonding pad of the LED die and another end of which is bonded to a wire-bonding pad of the carrier  10 . The first electronic component  11  has an active region (or light emitting area)  11   e  facing toward the first light transmission element  13 . 
     The second electronic component  12  is disposed on the carrier  10  and is physically separated from the first electronic component  11 . In some embodiments, the electronic component  12  may include a light detector which is, for example, a PIN diode (a diode including a p-type semiconductor region, an intrinsic semiconductor region, and an n-type semiconductor region) or a photo-diode or a photo-transistor. The electronic component  12  can be connected to the carrier, for example, by way of flip-chip or wire-bond techniques. The first electronic component  12  has an active region (or light detecting area)  12   d  facing toward the second light transmission element  14 . 
     The lid (or housing)  15  is disposed on the carrier  10 . The lid  15  has a wall structure  15   w  disposed between the electronic component  11  and the electronic component  12 . The lid  15  is substantially opaque to prevent undesired light emitted by the electronic component  11  from being directly transmitted to the electronic component  12 . 
     The lid  15  defines a first opening  13   h  above the first electronic component  11  and a second opening  14   h  above the second electronic component  12 . The first opening  13   h  and the second opening  14   h  are physically separated from each other. In some embodiments, a width D 1  of the first opening  13   h  is about equal to or greater than (e.g. is about 10% greater than, about 20% greater than, about 30% greater than, or more than about 30% greater than) an area of the light emitting area  11   e  of the first electronic component  11 , and a width D 3  of the second opening  14   h  is about equal to or greater than (e.g. is about 10% greater than, about 20% greater than, about 30% greater than, or more than about 30% greater than) an area of the light detecting area  12   d  of the second electronic component  12 . For example, an area of a projection of the first opening  13   h  on the carrier  10  is about equal to or larger than the area of the light emitting area  11   e  of the first electronic component  11 , and an area of a projection of the second opening  14   h  on the carrier  10  is about equal to or larger than the area of the light detecting area  12   d  of the second electronic component  12 . For example, the first opening  13   h  is configured such that the light emitting area  11   e  of the first electronic component  11  is exposed (e.g., fully exposed) from the lid  15  by the first opening  13   h , which can help in accurately determining a position of a center of the light emitting area  11   e  of the first electronic component  11  (e.g. during or after manufacture). In addition, the second opening  14   h  is configured such that the light detecting area  12   d  of the second electronic component  12  is exposed (e.g., fully exposed) from the lid  15  by the second opening  14   h , which can help in accurately determining a position of a center of the light detecting area  12   d  of the second electronic component  12  (e.g. during or after manufacture). 
     The lid  15  defines a first cavity  15   h   1  above the first opening  13   h  (e.g. the first opening  13   h  is defined by a portion of the lid  15  that constitutes a bottom of the cavity  15   h   1 ) configured to accommodate the first light transmission element  13  and a second cavity  15   h   2  above the second opening  14   h  (e.g. the second opening  14   h  is defined by a portion of the lid  15  that constitutes a bottom of the cavity  15   h   2 ) configured to accommodate the second light transmission element  14 . In some embodiments, a width D 5  of the first cavity  15   h   1  is greater than (e.g. is about 10% greater than, about 20% greater than, about 30% greater than, or more than about 30% greater than) the width D 1  of the first opening  13   h , and a width D 6  of the second cavity  15   h   2  is greater than (e.g. is about 10% greater than, about 20% greater than, about 30% greater than, or more than about 30% greater than) the width D 3  of the second opening  14   h . The first cavity  15   h   1  and the second cavity  15   h   2  are physically separated from each other. 
     The first light transmission element  13  is disposed within the first cavity  15   h   1  and on the first opening  13   h . The first light transmission element  13  is configured to allow transmission of light emitted from the first electronic component  11 . In some embodiments, the first light transmission element  13  is a lens. In some embodiments a width D 7  of the first light transmission element  13  is greater than the width D 1  of the first opening  13   h  and less than or about equal to the width D 5  of the first cavity  15   h   1 . In some embodiments, an adhesive layer  13   a  is disposed between the first light transmission element  13  and a sidewall of the first cavity  15   h   1  (e.g. in some embodiments in which the width D 7  of the first light transmission element  13  is less than the width D 5  of the first cavity  15   h   1 ). In some embodiments, the adhesive layer  13   a  includes thermal cured materials or optical cured materials. 
     The second light transmission element  14  is disposed within the second cavity  15   h   2  and on the second opening  14   h . The second light transmission element  14  is physically separated from the first light transmission element  13 . The second light transmission element  14  is configured to allow the transmission of the light received by the second electronic component  12 . In some embodiments, the second light transmission element  14  is a lens. In some embodiments a width D 8  of the second light transmission element  14  is greater than the width D 3  of the first opening  14   h  and less than or about equal to the width D 6  of the second cavity  15   h   2 . In some embodiments, an adhesive layer  14   a  is disposed between the second light transmission element  13  and a sidewall of the second cavity  15   h   2  (e.g. in some embodiments in which the width D 8  of the first light transmission element  14  is less than the width D 6  of the second cavity  15   h   2 ). 
     The first opaque layer  16  is disposed on the first light transmission element  13 . In some embodiments, the first opaque layer  16  may include a light absorbing layer, ink, photoresist or a metal layer. In some embodiments, the first opaque layer  16  is recessed from a top surface  151  of the lid  15 . The first opaque layer  16  defines a first aperture  16   h . The light emitted by the first electronic component  11  selectively passes through the first aperture  16   h , and other light emitted by the first electronic component  11  is substantially blocked or absorbed by the first opaque layer  16 . A center of the first aperture  16   h  is substantially aligned with the center of the light emitting area  11   e  of the first electronic component  11 . A width D 2  of the first aperture  16   h  is less than the width D 1  of the first opening  13   h . In some embodiments, the width of the first aperture  16   h  is less than about 250 μm. 
     The second opaque layer  17  is disposed on the second light transmission element  14 . The second opaque layer  17  is physically separated from the first opaque layer  16 . In some embodiments, the second opaque layer  17  may include a light absorbing layer, ink, photoresist or a metal layer. In some embodiments, the second opaque layer  17  is recessed from the top surface  151  of the lid  15 . The second opaque layer  17  defines a second aperture  17   h . The light emitted toward the second electronic component  12  selectively passes through the second aperture  17   h , and other light emitted toward the second electronic component  12  is substantially blocked or absorbed by the second opaque layer  17 . A center of the second aperture  17   h  is substantially aligned with the center of the light detecting area  12   d  of the second electronic component  12 . A width D 4  of the second aperture  17   h  is less than the width D 3  of the second opening  14   h . In some embodiments, the width of the second aperture  17   h  is less than about 250 μm. 
     In a comparative optical module, an aperture is directly formed in a lid by a machine; however, due to constraints of some such processes, the size of the aperture of the lid is not less than about 250 μm. In accordance with some embodiments shown in  FIG. 1 , the first and second opaque layers  16 ,  17  are respectively formed by printing or coating ink on the first and second light transmission elements  13 ,  14 . The first aperture  16   h  and the second aperture  17   h  are formed by lithographic technique, and thus the size of the apertures can be readily scaled down (e.g., to less than about 250 μm). By miniaturizing such apertures, undesired light (e.g., light from an external environment) which may be inadvertently detected by the light detector can be reduced, which can help to reduce a deviation between a measured or detected position and a real position of an object detected by the optical module, thus increasing the accuracy of the optical module. 
     In some embodiments, a panel including a light transmission element and an opaque layer may be placed on the lid to cover both of the light emitter and the light detector. However, since the relative locations of the apertures of the opaque layer may be fixed, it can be difficult to simultaneously control the alignment of the aperture of the opaque layer with the light emitter or the light detector. For example, one aperture of the opaque layer may be aligned with the light emitter, but another aperture may be misaligned with the light detector. In accordance with the embodiments shown in  FIG. 1 , the light transmission elements  13 ,  14  and the opaque layers  16 ,  17  are individually disposed over the first electronic component  11  (e.g. the light emitter) and over the second electronic component  12  (e.g. the light detector). The respective centers of the apertures  16   h ,  17   h  and the centers of the light emitting area  11   e  of the light emitter  11  and the light detecting area  12   d  of the light detector  12  can be individually detected and aligned, which can help to reduce an offset of alignment and to increase the accuracy of the optical device  1 . 
       FIG. 2  illustrates a cross-sectional view of some embodiments of an optical device  2  in accordance with the first aspect of the present disclosure. The optical device  2  is similar to the optical device  1  shown in  FIG. 1  except that first and second light transmission elements  23 ,  24  of the optical device  2  are plano-convex lenses. As shown in  FIG. 2 , a convex surface  23   a  of the first light transmission element  23  faces toward a first electronic component  11 , and a convex surface  24   a  of the second light transmission element  24  faces a second electronic component  12 . The convex surface  23   a  may protrude into an aperture  13   h  defined by the lid  15 . The convex surface  24   a  may protrude into an aperture  14   h  defined by the lid  15 . The plano-convex lenses may increase the density of the light that reaches the electronic components, which can help to improve the performance of the optical device  2 . 
       FIG. 3A  illustrates a cross-sectional view of some embodiments of a semiconductor device  3 A in accordance with a second aspect of the present disclosure. The semiconductor device  3 A includes the optical device  1  as shown in  FIG. 1 , a third opaque layer  31  and a lens  32 . Light cones, depicted by dashed lines, show some possible paths of light that can be transmitted to or from electronic components of the optical device  1 . In some embodiments, the semiconductor device  3 A can be implemented with the optical device  2  shown in  FIG. 2  in place of, or in addition to, the optical device  1 . 
     The third opaque layer  31  is disposed on the optical device  1 . The third opaque layer  31  defines an opening  31   h  that allows light to pass through. The lens  32  is disposed on the third opaque layer  31 . In some embodiments, the lens  32  may include or may be a glass portion (e.g. a glass panel) of a cell phone, a tablet, a notebook, a camera or other electronic devices equipped with a proximity sensor. 
       FIG. 3B  illustrates a cross-sectional view of some embodiments of a semiconductor device  3 B in accordance with the second aspect of the present disclosure. The semiconductor device  3 B is similar to the semiconductor device  3 A shown in  FIG. 3A  except that the second opaque layer  31  is replaced by a light filter layer  33 . Light cones, depicted by dashed lines, show some possible paths of light that can be transmitted to or from electronic components of the optical device  1 . The light filter layer  33  does not define an opening (e.g. is devoid of an opening over the apertures of the optical device  1 ). The light filter layer  33  is configured to allow light with predetermined wavelengths to pass through. In some embodiments, the light filter layer  33  is implemented in conjunction with the third opaque layer  31 . 
       FIG. 4A ,  FIG. 4B  and  FIG. 4C  illustrate a method for manufacturing an optical device  1  as shown in  FIG. 1  in accordance with some embodiments of the present disclosure. Although some processes, operations or steps are described in the following with respect to each of a plurality of components, any of those processes, operations or steps may be selectively performed with respect to one of the plurality of components, or with respect to some number in between one and the full plurality of components. 
     Referring to  FIG. 4A , the carrier  10  is provided. The first electronic component  11  (e.g., a light emitter) and the second electronic component  12  (e.g., a light detector) are placed on the carrier  10 . The first electronic component  11  and the second electronic component  12  are physically separated from each other. 
     The lid (or housing)  15  is placed on the carrier  10 . The lid  15  is arranged so that the wall structure  15   w  of the lid  15  is disposed between the electronic component  11  and the electronic component  12 , the first opening  13   h  of the lid  15  is disposed above the first electronic component  11  and the second opening  14   h  of the lid  15  is disposed above the second electronic component  12 . In some embodiments, the width D 1  of the first opening  13   h  is about equal to or greater than (e.g. is about 10% greater than, about 20% greater than, about 30% greater than, or greater than about 30% greater than) an area of the light emitting area  11   e  of the first electronic component  11 , and the width D 3  of the second opening  14   h  is about equal to or greater than (e.g. is about 10% greater than, about 20% greater than, about 30% greater than, or greater than about 30% greater than) an area of the light detecting area  12   d  of the second electronic component  12 . For example, the first opening  13   h  is configured such that the light emitting area  11   e  of the first electronic component  11  is exposed from the lid  15  by the first opening  13   h , which can help in accurately determining a location of a center of the light emitting area  11   e  of the first electronic component  11  in subsequent operations. In addition, the second opening  14   h  is configured such that the light detecting area  12   d  of the second electronic component  12  is exposed from the lid  15  by the second opening  13   h , which can help in accurately determining a location of a center of the light detecting area  12   d  of the second electronic component  12  in subsequent operations. The first opening  13   h  and the second opening  14   h  are physically separated from each other. 
     The lid  15  has a first cavity  15   h   1  above the first opening  13   h  and a second cavity  15   h   2  above the second opening  14   h . In some embodiments, a width D 5  of the first cavity  15   h   1  is greater than a width D 1  of the first opening  13   h , and a width D 6  of the second cavity  15   h   2  is greater than a width D 3  of the second opening  14   h . The first cavity  15   h   1  and the second cavity  15   h   2  are physically separated from each other. 
     In some manufacturing process embodiments, there is a first offset tolerance for placing the lid  15  (e.g. on the carrier  10 ) and there is a second offset tolerance for placing the first or second electronic components  11 ,  12  (e.g. on the carrier  10 ). At least one of the widths D 1 , D 3  of the first opening  13   h  and the second opening  14   h  is larger than or about equal to a sum of the first offset tolerance, the second offset tolerance and (i) a width of the area of the light emitting area  11   e  of the first electronic component  11  or (ii) a width of the area of the light detecting area  12   d  of the second electronic component  12 . 
     Referring to  FIG. 4B , the first light transmission element  13  and the second light transmission element  14  are provided. In some embodiments, the first and second light transmission elements  13 ,  14  are provided by dividing a panel of a transmission element into multiple individual light transmission elements. In some embodiments the width D 7  of the first light transmission element  13  is greater than the width D 1  of the first opening  13   h  and less than or about equal to the width D 5  of the first cavity  15   h   1  (e.g. is about 10% less than, about 20% less than, about 30% less than, or less than about 30% less than). The width D 8  of the second light transmission element  14  is greater than the width D 3  of the first opening  14   h  and less than or about equal to the width D 6  of the second cavity  15   h   2  (e.g. is about 10% less than, about 20% less than, about 30% less than, or less than about 30% less than). 
     The first and second opaque layers  16 ,  17  are respectively formed on the first and second light transmission elements  13 ,  14 . In some embodiments, the first and second opaque layers  16 ,  17  can be formed by plating or coating ink on the first and second light transmission elements  13 ,  14 . The first and second apertures  16   h ,  17   h  are then formed to penetrate the first and second opaque layers  16 ,  17  and to expose a portion of the first and second light transmission elements  13 ,  14 . In some embodiments, the first and second apertures  16   h ,  17   h  can be formed by photolithography, chemical etching, laser drilling, or other suitable processes. In some embodiments, the width D 2  of the first aperture  16   h  is less than the width D 1  of the first opening  13   h , and the width D 4  of the second aperture  17   h  is less than the width D 3  of the second opening  14   h . In some embodiments, the width of each of the first and second apertures  16   h ,  17   h  is less than about 250 μm. 
     A center C 1  of the first aperture  16   h  and a center C 2  of the second aperture  17   h  can be detected or calculated. The center C 1  or C 2  of the first aperture  16   h  or the second aperture  17   h  is determined by an image capturing device ICD and a processor. Detecting or calculating a center C 3  of the light emitting area  11   e  of the first electronic component  11  and a center C 4  of the light detecting area  12   d  of the second electronic component  12  can be performed in a similar manner. For example, the center C 3  or C 4  of the light emitting area  11   e  of the first electronic component  11  or the light detecting area  12   d  of the second electronic component  12  is determined by an image capturing device ICD and a processor. 
     Referring to  FIG. 4C , the center C 1  of the first aperture  16   h  is aligned with the center C 3  of the light emitting area  11   e  of the first electronic component  11 , and the first light transmission element  13  together with the first opaque layer  16  are disposed within the first cavity  15   h   1  by, for example, a pick and place operation. The center C 2  of the second aperture  17   h  is aligned with the center C 4  of the light detecting area  12   d  of the second electronic component  12 , and the second light transmission element  14  together with the second opaque layer  17  are disposed within the second cavity  15   h   2  by, for example, a pick and place operation. In some embodiments, the first opaque layer  16  and the second opaque layer  17  are recessed from a top surface  151  of the lid  15 . 
     In some embodiments, before the placement of the first and second light transmission elements  13 ,  14 , the adhesive layer  13   a  can be placed adjacent to sidewalls of the first and second cavities  15   h   1 ,  15   h   2 , which can help to secure the first and second light transmission elements  13 ,  14  (e.g. in implementations in which the widths D 7 , D 8  of the first and second light transmission elements  13 ,  14  are less than the widths D 5 , D 6  of the first and second cavities  15   h   1 ,  15   h   2 ). In some embodiments, the adhesive layer  13   a  includes thermal cured materials or optical cured materials. 
     As used herein, the terms “substantially,” “substantial,” “approximately,” and “about” are used to denote and account for small variations. For example, when used in conjunction with a numerical value, the terms can refer to a range of variation of less than or equal to ±10% of that numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. As another example, a thickness of a film or a layer being “substantially uniform” can refer to a standard deviation of less than or equal to ±10% of an average thickness of the film or the layer, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. The term “substantially coplanar” can refer to two surfaces within 50 μm of lying along a same plane, such as within 40 within 30 within 20 within 10 or within 1 μm of lying along the same plane. Two components can be deemed to be “substantially aligned” if, for example, the two components overlap or are within 200 within 150 within 100 within 50 within 40 within 30 within 20 within 10 or within 1 μm of overlapping. Two surfaces or components can be deemed to be “substantially perpendicular” if an angle therebetween is, for example, 90°±10°, such as ±5°, ±4°, ±3°, ±2°, ±1°, ±0.5°, ±0.1°, or ±0.05°. When used in conjunction with an event or circumstance, the terms “substantially,” “substantial,” “approximately,” and “about” can refer to instances in which the event or circumstance occurs precisely, as well as instances in which the event or circumstance occurs to a close approximation. 
     In the description of some embodiments, a component provided “on” another component can encompass cases where the former component is directly on (e.g., in physical contact with) the latter component, as well as cases where one or more intervening components are located between the former component and the latter component. 
     Additionally, amounts, ratios, and other numerical values are sometimes presented herein in a range format. It can be understood that such range formats are used for convenience and brevity, and should be understood flexibly to include not only numerical values explicitly specified as limits of a range, but also all individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly specified. 
     While the present disclosure has been described and illustrated with reference to specific embodiments thereof, these descriptions and illustrations do not limit the present disclosure. It can be clearly understood by those skilled in the art that various changes may be made, and equivalent elements may be substituted within the embodiments without departing from the true spirit and scope of the present disclosure as defined by the appended claims. The illustrations may not necessarily be drawn to scale. There may be distinctions between the artistic renditions in the present disclosure and the actual apparatus, due to variables in manufacturing processes and such. There may be other embodiments of the present disclosure which are not specifically illustrated. The specification and drawings are to be regarded as illustrative rather than restrictive. Modifications may be made to adapt a particular situation, material, composition of matter, method, or process to the objective, spirit and scope of the present disclosure. All such modifications are intended to be within the scope of the claims appended hereto. While the methods disclosed herein have been described with reference to particular operations performed in a particular order, it can be understood that these operations may be combined, sub-divided, or re-ordered to form an equivalent method without departing from the teachings of the present disclosure. Therefore, unless specifically indicated herein, the order and grouping of the operations are not limitations of the present disclosure.