Abstract:
A package support including: metal frames connected together; one or more dielectric materials disposed in an inner gap of the metal frames; wherein: the package support has a frame region and a function region; wherein the function region has complete upper and lower surfaces configured to prevent leakage if at least one of the entire upper or lower surfaces is covered with an encapsulant material. A fabrication method allows for manufacturing the package support with a high cell density, relatively low price, high reflectivity, good heat dissipation, and high reliability. The LED package using the package support has a smaller size and improved dissipation properties.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a continuation of and claims priority to Chinese Patent Application Nos. CN 201420075500.7 filed on Feb. 21, 2014, CN 201420695174.X filed on Nov. 19, 2014, and CN 201420822588.4 filed on Dec. 23, 2014. The disclosures of these applications are hereby incorporated by reference in their entirety. 
       BACKGROUND 
       [0002]    Light Emitting Diode (LED) is a semiconductor light-emitting device fabricated by employing P-N junction electroluminescence principles. Advantageous in environmental protection, high luminance, low power consumption, long service life, low working voltage and easy integration, the LED is the fourth-generation new light source following incandescent lamp, fluorescent lamp and high intensity discharge lamp (HID) (e.g., HPSL and metal halide lamp). 
       SUMMARY 
       [0003]    Existing LED package supports have low cell density (only 200-300 cells per support), which wastes material and reduces production efficiency; the holes at the support also impede advanced technologies such as Molding. In addition, the large support cell area is to the disadvantage of luminous efficiency improvement and convenient optical design. Therefore, a new support is needed for LED package to solve the above problems. 
         [0004]    Each cell of the existing support is much larger than the chip, leading to increased consumption of phosphor and package encapsulant by the LED package structure. After the scattering of emitted light and the phosphor, the packaged body has increased consumption. Therefore, it may be necessary to make certain improvements to the existing LED package structure that impedes the shrinkage of the sizes. 
         [0005]    To solve the above problems, the present disclosure provides a package support, fabrication method and LED package, wherein, the package support has such features as high cell density, low price, high reflectivity, good heat dissipation and high reliability. The LED package has smaller size and better heat dissipation. 
         [0006]    According to a first aspect of the present disclosure, a package support having metal frameworks or frames connected and an inner gap filled with dielectric material. The package support has a frame region and a function region. The function region has complete upper and lower surface with no penetrating holes, which prevents leakage when the entire surface is covered with encapsulant material. 
         [0007]    Preferably, the metal framework forms a buckle at vertical direction with the dielectric material. 
         [0008]    Preferably, the support thickness is less than 0.5 mm. 
         [0009]    Preferably, the metal framework is at least two-layer structure and the surface is high-reflectivity material. 
         [0010]    Preferably, the metal framework is high-thermal conductivity material, at least comprising one of Cu and Al. More preferably, the metal material is an at least two-layer structure and the surface is high-thermal conductivity material, at least comprising one of Ag and Al. 
         [0011]    Preferably, the metal framework comprises a front framework and a back framework. The front framework is vertically stacked with the back framework. The back framework is connected and the area is larger than the front framework. 
         [0012]    Preferably, the dielectric material is thermosetting plastic, at least comprising one of SMC, EMC and Polyester. More preferably, the dielectric material is black EMC material and the upper surface is covered with highly reflective insulation layer. The highly reflective insulation layer&#39;s reflectivity to 450 nm wavelength light is more than 90%. 
         [0013]    Preferably, the dielectric material has two-layer structure, in which, the bottom layer is black plastic and the top layer is white plastic. 
         [0014]    Preferably, the package support comprises at least one function region. More preferably, to enhance structure strength, the support is divided into different function regions, which are separately from each other by metal. 
         [0015]    Preferably, the dielectric materials in each function region are connected. 
         [0016]    Preferably, the function region has a series of tightly-arranged cells (at least 500 cells). In some embodiments, each cell area in the function region is not more than 9 mm 2 ; in some embodiments, the upper surface of each cell is square; in some embodiments, each cell has two metal blocks of equal size as the metal framework. The two metal blocks have no metal connection inside the cell. 
         [0017]    Preferably, the frame region has alignment marks and air discharge ducts for half etching cutting. 
         [0018]    Preferably, the frame region has a positioning hole. 
         [0019]    According to a second aspect of the present disclosure, a package support having metal frameworks connected and an inner gap filled with dielectric material. The metal framework is a multi-layer structure, each layer having different patterns. 
         [0020]    Preferably, the metal framework is an at least two-layer structure. The areas of dielectric materials decrease layer by layer from upper layer to bottom layer. In some preferred embodiments, the dielectric material area at bottom layer is not less than 40% of that of the upper layer. 
         [0021]    Preferably, the metal framework is an at least two-layer structure. The dielectric material area ratio of at least two layers is between 0.4:1 and 2.5:1. 
         [0022]    Preferably, the metal framework is an at least two-layer structure. The dielectric material area ratio of top layer and any of lower layers is between 1:2.5 and 1:0.4. 
         [0023]    Preferably, the metal framework is an at least two-layer structure. The dielectric material area ratio of at least two layers is between 0.5 and 1.2. More preferably, at least two layers of dielectric materials are equal in size. Most preferably, dielectric material areas of all layers are equal. 
         [0024]    Preferably, the metal framework has an upper layer and a lower layer, wherein, the dielectric material area of the lower layer is between 0.4 times and 2.5 times of that of the upper layer. In some preferred embodiments, the dielectric material area of the lower layer is between 0.5 times and 1.2 times of that of the upper layer. 
         [0025]    Preferably, the metal framework has an upper layer and a lower layer and the dielectric material appears in “T” and “Inversed-T” shape. 
         [0026]    Preferably, the metal framework is a three-layer structure and the dielectric material appears “H” and “Cross” shape. 
         [0027]    According to a third aspect of the present disclosure, a fabrication method for package support, comprising: providing a metal substrate and determining the front pattern and the back pattern, in which, the back patterns are connected, and the front pattern is smaller than the back pattern; etching the front surface and the back surface of the metal substrate by two times to remove the regions beyond the front pattern and the back pattern; forming gap inside the metal substrate to form a metal framework; filling in dielectric material in the gap, wherein, the metal framework is parallel with the upper surface of the dielectric material. 
         [0028]    The above package support has high cell density and efficiently saves package material; besides, it is easy for light emitting and improves lighting effect; due to small and thin cell, the support has good heat dissipation with application of material like Cu; the function region of the support is free of penetrable holes and the buckle structure is arranged between the metal and the dielectric material, preventing from leakage and facilitating the application of advanced technologies like Molding. 
         [0029]    According to a fourth aspect of the present invention, a LED package, comprising a substrate with complete front and back surfaces, comprising at least two metal blocks and an insulation part, wherein, the metal blocks are inlaid in the insulation part and expose part of upper and lower surfaces. An electrical insulation region is set between the metal blocks; a LED chip over the metal block of the substrate and forms electrical connection with at least two metal blocks; and package encapsulant covering over the LED chip surface and part of the substrate. In this technical proposal, the LED package substrate is the package support. 
         [0030]    Preferably, the metal block has projected connection parts that extend to the substrate edge. 
         [0031]    Preferably, the substrate has at least two metal blocks for electric conduction and heat dissipation. Each metal block has at least three projected connection parts. In some embodiments, two metal blocks are axial symmetric. 
         [0032]    Preferably, the metal block has at least one projected connection part appearing in angle of inclination with the metal block. In some embodiments, two metal blocks are rotational symmetric at 180°. 
         [0033]    Preferably, the electrical insulation region between metal blocks appears in “I” or “H” shape. 
         [0034]    Preferably, the electrical insulation region between metal blocks appears in “S” or inverted-“S” shape. 
         [0035]    Preferably, the metal block forms bucket with the insulation part at vertical direction. 
         [0036]    Preferably, in the substrate, divide the metal blocks into an upper part and a lower part at vertical direction, wherein, the upper part is the front surface of the substrate and the lower part is the back surface of the substrate. The upper part and the lower part have different shapes. In some embodiments, some part of the upper part of the metal block horizontally projects towards the lower part and some part of the lower part of the metal block horizontally projects towards the upper part. In some embodiments, the projected connection part is at the upper part or the lower part of the metal block. 
         [0037]    Preferably, the package encapsulant is 0.2-5 mm thick. In some embodiments, the package encapsulant is 0.2-3 mm thick; in some embodiments, to enlarge the light-emitting angle of the package, the package encapsulant is thicken (preferably: 0.5-5 mm) 
         [0038]    In some embodiments, to further enlarge the light-emitting angle of the package, the light-emitting surface side of the package encapsulant has an arc shape. 
         [0039]    Preferably, the LED package also comprises a wavelength conversion device, which directly adds phosphor in the package encapsulant or directly sets the wavelength conversion material layer over the LED chip surface/package encapsulant surface. 
         [0040]    The upper and lower surfaces of the LED package substrate are flat surfaces. The LED chip is directly located at the metal block of the substrate. Through the electric conduction and heat dissipation of the metal block, the heat dissipation of the package is improved. Wider light-emitting angle and higher light-emitting efficiency are achieved for the light will not be blocked by the support (e.g., bowl cup) side wall; the metal block of the substrate is inlaid in the insulation part. The upper and lower parts of each metal block are different in shape, forming a bucket structure with the insulation part, which improves the soundness of the package. Further, the package support is a multi-layer structure, each layer having different patterns. The support warping can be solved by designing the area ratio of dielectric materials in each layer. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0041]      FIG. 1  is a front view of an LED package support according to some embodiments. 
           [0042]      FIG. 2  is a back view of a LED package support according to some embodiments. 
           [0043]      FIG. 3  is a frame region of the package support as shown in  FIG. 1 . 
           [0044]      FIG. 4  is a front view and back view of frame region of the package support as shown in  FIG. 1 . 
           [0045]      FIG. 5  is an enlarged view of the metal framework of the package support as shown in  FIG. 4 . 
           [0046]      FIG. 6  is a local enlarged back view of the package support as shown in  FIG. 4 . 
           [0047]      FIG. 7  is an enlarged view of any cell of the function region in the package support as shown in  FIG. 4 . 
           [0048]      FIG. 8  is a side sectional view of a first type of cells of the package support as shown in  FIG. 7 ; 
           [0049]      FIG. 9  is a side sectional view of a second type of cells of the package support as shown in  FIG. 7 ; 
           [0050]      FIG. 10  is a side sectional view of a third type of cells of the package support as shown in  FIG. 7 . 
           [0051]      FIG. 11  is a side sectional view of a first type of the support showing only a few cells, where the profile position is the dotted line A--&gt;B in  FIG. 4 ; 
           [0052]      FIG. 12  is a side sectional view of a second type of the support; 
           [0053]      FIG. 13  is a side sectional view of a third type of the support; 
           [0054]      FIG. 14  is a side sectional view of a fourth type of the support. 
           [0055]      FIG. 15  is a sectional view of a first type of LED package according to some embodiments. 
           [0056]      FIG. 16  illustrates the front pattern of the substrate of the LED package as shown in  FIG. 15 . 
           [0057]      FIG. 17  illustrates the back pattern of the substrate of the LED package as shown in  FIG. 15 . 
           [0058]      FIG. 18  illustrates a variation of the LED package as shown in  FIG. 15 . 
           [0059]      FIG. 19  illustrates the back pattern of the substrate of a second type of LED package according to some embodiments. 
           [0060]      FIG. 20  is a sectional view of a second type of LED package according to some embodiments. 
           [0061]      FIG. 21  illustrates a variation of the LED package as shown in  FIG. 20 ; 
           [0062]      FIG. 22  illustrates another variation of the LED package as shown in  FIG. 20 . 
       
    
    
       [0063]    In the drawings:  101 : support function region;  101   a:  front surface of the support function region;  101   b:  back surface of the support function region;  101 - 1 : first function region;  101 - 2 : second function region;  101 - 3 : third function region;  102 : support frame region;  103 : positioning hole;  104 : alignment mark;  105 : air discharge duct;  106 : filling mouth;  107 : structural strength region;  110 : metal framework;  110   a:  front metal framework;  110   b:  back metal framework;  120 : dielectric material;  200 : any cell in the function region;  210 : metal block;  220 : insulation part;  221 : bottom of the insulation part;  222 : top layer of the insulation part;  1100 : package substrate;  1110 : metal block;  1110   a:  upper part of the metal block;  1110   b:  lower part of the metal block;  1111 - 114 : projected connection part;  1120 : insulation part;  1130 : electrical insulation region;  1200 : LED chip;  1300 : package encapsulant. 
       DETAILED DESCRIPTION 
       [0064]    The LED package support, fabrication method and LED package structure will be described in detail with reference to the accompanying drawings and examples, to help understand and practice the disclosed embodiments, regarding how to solve technical problems using technical approaches for achieving the technical effects. 
         [0065]      FIGS. 1 and 2  are front and back views, respectively, of a package support according to some embodiments. A package support comprises a function region  101  and a frame region  102 . Specifically, the function region  101  has no penetrating holes, which prevents leakage when the entire surface is covered with encapsulant. It has complete front surface  101   a  and back surface  101   b,  and the patterns of the front surface  101   a  and the back surface  101   b  are different. Detailed description will be made by referring to other drawings; the frame region  102  has a positioning hole  103  and alignment marks  104 . In some embodiments, the cutting mark  107  of the support appears in “Line” or “Cross” shape. The cutting mark may be approximate to or far from the function region. In some preferred embodiments, an air discharge duct  105  and a filling mouth  106  may be set. As shown in  FIGS. 1-2 , the function region  101  of the package support comprises three regions of same area. In some embodiments, the function region  101  can be a single region or comprise several regions. The areas of different regions can be same or different. If the function region  101  has several regions, it is preferably that each region has same area. To intensifying the support structure, a structure intensive region  107  made of metal may be arranged in the function region. Of course, in the structure intensive region  107 , the front surface is conductive material and the back surface is dielectric material, or the back surface is conductive material and the front surface is dielectric material to ensure that areas of dielectric materials in the front and back surfaces are approximate so as to eliminate the support warping. 
         [0066]      FIG. 3  shows the structure of the frame region  102  of the package support as shown in  FIG. 1 . The frame region  102  is made up of metal.  FIG. 4  shows the front view and back view of a single function region of the package support. Specifically, the function region  101  has a series of tightly-arranged cells (at least 500 cells) and comprises the metal framework or frames  110  and the dielectric material  120 , wherein, the metal framework  110  connects with the metal of the frame region  102  to form an entire package support frame. The pattern region  110  (filled with horizontal line as shown in the front view) is the metal framework. The white pattern region  120  is plastic. As shown in the figure, the plastics in the entire function region are connected together; in the back surface, the white pattern region  110  is the metal framework and the black pattern region  120  is plastic. As shown in the figure, the metal frameworks of the entire function region are connected together. 
         [0067]      FIG. 5  is the enlarged view of the metal framework  110  of the function region  101  as shown in  FIG. 4 , which intercepts four cells in the function region. Specifically, the metal framework  110  comprises the front framework  110   a  and the back framework  110   b,  which are overlapped vertically, wherein, the back frameworks  110   b  are connected and the area is larger than that of the front framework. Inside the metal framework  110  is the gap  130 . The gap is filled with the dielectric material  120 .  FIG. 6  is the local back enlarged view of the function region  101  as shown in  FIG. 4 , which also intercepts four cells in the function region. The white pattern region in the figure is the back metal framework  110   b  of the function region  101  (i.e., the back framework  110   b  as shown in  FIG. 5 ) and the black pattern region is the dielectric material  120 . 
         [0068]      FIG. 7  is the enlarged top view of any cell  200  of the function region  110  as shown in  FIG. 4 . Specifically, the cell  200  comprises two metal block  210  (i.e., the metal framework  110  as shown in  FIG. 5 ) and the insulation part  220  (i.e., the dielectric material  120  as shown in  FIG. 6 ). The two metal blocks  210  have no metal connection inside the cell. In some embodiments, it is preferable that the area of each cell  200  is not more than 9 mm 2 . The upper surface of each cell is square. The metal block  210  is high-thermal conductivity material, at least comprising one of Cu and Al, which can be single-layer structure or multi-layer structure. Two-layer structure is preferred. The surface is high-thermal conductivity material, at least comprising one of Ag and Al; the insulation part  220  is thermosetting plastic, at least comprising one of SMC, EMC and Polyester. In a preferred embodiment of the present disclosure, the metal block  210  is a three-layer structure comprising silvering upper and lower copper surfaces. Only one layer is used for explanation.  FIGS. 8-10  are the three side sectional structures of the cell as shown in  FIG. 7 . The insulation part  220  of the cell  200  as shown in  FIG. 8  is a single-layer structure. The material is high reflectivity layer (reflectivity&gt;90%), which is preferably white EMC or SMC. The insulation part  220  of the cell  200  as shown in  FIG. 9  is a two-layer structure. The bottom part  221  is material with high reliability, mechanical strength and good metal adhesiveness, which is preferably black EMC, The top layer  222  is high-reflectivity and high temperature resistance material, which is preferably high-reflectivity silicone ink. The insulation part  220  of the cell  200  as shown in  FIG. 10  is also a single-layer structure but the material has high reliability, preferably black EMC. 
         [0069]    To avoid support warping, it is preferable that the areas of the dielectric material  120  at support front and the dielectric material  120  at the back surface are not so different. Specifically, the area ratio of the dielectric materials between the front and back surfaces is between 0.4:1 and 2.5:1 and more preferably, between 0.8:1 and 1.2:1. This embodiment also considers heat dissipation and warping problem of the support. The areas of dielectric materials decrease layer by layer from upper layer to bottom layer, wherein, it is preferable that the dielectric material area at bottom layer is not less than 40% of that of the upper layer. Taking the support as shown in  FIG. 1  for example, the entire support is 5000 mm 2 . The dielectric material at front surface is 2000 mm 2  and the dielectric material at back surface is preferably not less than 800 mm 2 . 
         [0070]      FIGS. 11-14  are side sectional views of the supports of different types (only displaying a few cells). The profile position is the dotted line A-&gt;B in  FIG. 4 . Referring to  FIG. 11 , in consideration of approximate areas of the dielectric materials between the upper and lower layers, the dielectric material  120  appears in “T” and “Inversed-T” shape to eliminate the support warping. Referring to  FIG. 12 , the package support is a three-layer structure. To achieve approximate area of the dielectric materials for different layers, the dielectric material  120  appears in “H” and “Cross” shape. It is to be understood that, the dielectric materials  120  can all appear in “H” and “Cross” shape as long as the dielectric materials of the upper and lower layers are approximate to eliminate warping. Preferably, the area ratio of the dielectric materials of the middle layer and the lower layer and the dielectric material of the upper layer is between 0.4-2.5. Most preferably, the area ratio of dielectric materials for the three layers is 1:1:1. In some embodiments, the support surface may not be flat and the dielectric material may project over the surface or the metal framework may project over the surface, as shown in  FIG. 13  and  FIG. 14  respectively. As shown in  FIG. 13 , the package support has three layers, wherein, the top layer only has the dielectric material and has no metal framework, and the middle layer and the lower layer comprise the dielectric material and the metal framework. To eliminate the support warping, the dielectric materials of the middle layer and the lower layer may appear in “T” shape and “Inversed-T” shape. In consideration of the impact of the dielectric material at top layer, the dielectric material area of the middle layer may be a little smaller than that of the lower layer the dielectric material. Preferably, the area ratio is between 0.4:1 and 1:1, and most preferably, 0.8:1.  FIG. 7  adopts same method. The dielectric material may appear in “T” shape and “Inversed-T” shape. 
         [0071]    A simple description will be made for a fabrication method of the package support. A fabrication method for package support, comprising: providing a metal substrate and determining the front pattern and the back pattern, in which, the back patterns are connected, and the front pattern is smaller than the back pattern; etching the front surface and the back surface of the metal substrate by two times to remove the regions beyond the front pattern and the back pattern; forming gap inside the metal substrate to form a metal framework; filling in plastic in the gap, wherein, the metal framework is parallel with the upper surface of the plastic. Transfer molding is used for filling plastic: placing the etched metal substrate in the flat mould (the upper and lower moulds are flat die) and pressing the plastic over the metal substrate; filling plastic from the filling mouth at side of the mould until the plastic is filled up with the etched gap. After transfer molding, take out the support, and remove the burr with Deflash. Level out the plastic surface; heat the support to above flowing temperature Tf for plastic smashing. Lower the temperature to normal temperature to keep the entire support flat with no warping. 
         [0072]      FIGS. 15-17  illustrate a first LED package according to some embodiments, wherein  FIG. 16  and  FIG. 17  are the front pattern and the back surface pattern, respectively, of the substrate of the LED package.  FIG. 15  is the sectional view of the package cut along the Line A-A as shown in  FIG. 17 . 
         [0073]    Referring to  FIG. 15 , a LED package, comprising: a substrate  1100 , a LED chip  1200  and a package encapsulant  1300 . The front and back surfaces of the substrate  1100  are flat and complete surfaces, comprising two metal blocks  1110  and an insulation part  1120 ; the metal block  1110  is inlaid in the insulation part  1120  and expose part of upper and lower surfaces. An electrical insulation region  1130  is set between the metal blocks  1110 ; the LED chip  1200  is over the front surface of the two metal blocks  1110  and forms electrical connection; and the package encapsulant  1300  is over the LED chip  1200  surface and over part of the substrate. 
         [0074]    In this embodiment, the insulation part  1120  of the substrate is white plastic, or thermal plastic (e.g., PPA, PCT, LCP) or thermal setting plastic (e.g., EMC, SMC, Polyester). Specifically, plastics are filled around the metal block  1110 . Upper part and lower part expose part of metal to make the metal block  1110  inlaid in the insulation part  1120 . The front surface of the metal block  1110  is the LED chip die bonding platform of the function region. The two metal blocks have one LED chip each. The two chips are connected by gold thread (or silver, copper and aluminum threads) for electrical conduction. The two chips may be in series or in parallel. Referring to  FIG. 15  again, taking the Reference Plane C as boundary, vertically divide the metal block  1110  into upper part  1110   a  and lower part  1110   b  of different shapes. Specifically, at the place near the electrical insulation region  1130 , the upper part  1110   a  of the metal block horizontally projects over the lower part  1110   b;  and at the place near the substrate edge, the lower part  1110   b  of the metal block horizontally projects over the upper part  1110   a,  thus forming a bucket at vertical direction between the metal block  1110  and the insulation part  1120 . Referring to  FIG. 17 , each metal block  1110  has three projected connection parts  1111 ,  1112  and  1113 , which extend to the substrate edge. Each projected connection part is at the lower part  1110   b  of the metal block (in some embodiments, the projected connection part can be at the upper part of the metal block). 
         [0075]    The package encapsulant  1300  covers the five surfaces (except the bottom) of the chip, part of the surface layer of the metal block and the plastic. The package encapsulant may comprise phosphor for wavelength conversion. The package encapsulant can be 0.2-5 mm thick. 
         [0076]    In the above structure, the metal blocks  1110  are axial symmetric. The electrical insulation region between them appears in “I” shape (or “H” shape, based on the chip shape) for electrical conduction and heat dissipation, wherein, one metal block is positive pole and the other metal block is negative pole. To distinguish the positive and negative poles, the positive and negative pole marks may be formed on the back surface of the substrate. Referring to  FIG. 18 , an indent part may be formed at the inner side of the metal block at right to indicate it is positive (or negative). 
         [0077]      FIGS. 19 and 20  illustrate a second LED package according to some embodiments, wherein,  FIG. 19  is the back surface pattern of the substrate of the LED package and  FIG. 20  is the section view of the package cut along the Centerline B-B as shown in  FIG. 19 . The front pattern of the substrate is same as that in Embodiment 1. 
         [0078]    Referring to  FIG. 19 , the difference between this embodiment and Embodiment 1 is that: the metal blocks are rotational symmetric at 180°. The electrical insulation region between them appears in “S” shape (or Inversed-S shape). Each metal block has four projected connection parts  1111 ,  1112 ,  1113  and  1114 . Taking the metal block  1110  at left as example, the projected connection parts  1111  and  1113  are at the left of the front and back ends of the metal block, the projected part  1112  is at the middle part at the left of the metal block and the projected part  1114  is at the right part of the back of the metal block and appears in angle of inclination with the metal block. In this embodiment, the package encapsulant  1300  is 0.2-3 mm thick, which can be 1 mm. 
         [0079]    Referring to  FIG. 21 , the thickness of the package encapsulant can be increased to enlarge the light emitting angle of the package, which is 0.5-5 mm, and preferably, 2-5 mm. Referring to  FIG. 22 , to further enlarge and light emitting angle of the package, the light-emitting side of the package encapsulant  1300  appears in arc shape. 
         [0080]    Although specific embodiments have been described above in detail, the description is merely for purposes of illustration. It should be appreciated, therefore, that many aspects described above are not intended as required or essential elements unless explicitly stated otherwise. Various modifications of, and equivalent acts corresponding to, the disclosed aspects of the exemplary embodiments, in addition to those described above, can be made by a person of ordinary skill in the art, having the benefit of the present disclosure, without departing from the spirit and scope of the disclosure defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures.