Patent Publication Number: US-8113687-B2

Title: Modular LED lighting fixture

Description:
PRIORITY STATEMENT 
     This non-provisional patent application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 60/817,110, filed Jun. 29, 2006, the entire contents of which are hereby incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Field 
     Example embodiments in general relate to a modular light emitting diode (LED) lighting fixture. 
     2. Description of the Related Art 
     Light emitting diodes (LEDs) are widely used in consumer lighting applications. In consumer applications, one or more LED dies (or chips) are mounted within a LED package or on an LED module, which may make up part of a lighting fixture which includes one or more power supplies to power the LEDs. The package or module in a lighting fixture includes a packaging material with metal leads (to the LED dies from outside circuits), a protective housing for the LED dies, a heat sink, or a combination of leads, housing and heat sink. Various implementations of the LED lighting fixtures including one or more LED modules are available in the marketplace to fill a wide range of applications, such as area lighting, indoor lighting, backlighting for consumer electronics, etc. 
     Conventional area lighting such as roadway lights uses high pressure sodium (HPS) bulbs which provide omni-directional light. Reflectors are used to direct some of this light, but much of the light is lost illuminating unintended spaces. For example with HPS bulbs, the typical lumen amount will be in the tens of thousands of lumens, but all of that output does not illuminate the intended area, such as a roadway area for example. 
     LEDs offer improved light efficiency, a longer lifetime, lower energy consumption and reduced maintenance costs, as compared to HPS light sources. Conventional HPS bulbs are susceptible to maintenance loss and surface, dirt and other losses. Conventional area lighting fixtures are attached on poles, include omni-directional HPS bulbs, and employ reflectors to illuminate the roadway in different patterns based on different situations. 
       FIGS. 7A to 7G  show types of roadway illumination. The Illuminating Engineering Society of North America (IESNA) is the recognized technical authority on illumination and puts out specifications for the five primary types of roadway illumination. As shown in  FIGS. 7A to 7G , there are five primary types of roadway illumination. Type I illumination is a direct illumination in two directions along the direction of the roadway (if the road is a single road) and/or in a straight directional pattern at a cross section as shown in  FIG. 7B .  FIG. 7C  shows an Omni directional lighting pattern across the entire intersection, and Fig. shows a lighting fixture which directs light at an angle to normal in either two directions, or in four directions as shown in  FIG. 7E . 
     Type III illumination in  FIG. 7F  shows a different angled illumination from normal as compared to Type II in  FIG. 7D , where the angle of illumination from normal is narrower to reflect a smaller coverage area. Type IV illumination ( FIG. 7G ) has an even narrower angle of illumination from normal to create a different, smaller illumination area than either Type III or Type II. 
     Conventionally, these HPS lighting fixtures must be replaced with a completely different fixture to change the lighting pattern at a given location. In order to change the shape and brightness of light output from the HPS fixture, there is no way to alter the pattern other than replacing the entire fixture. Similarly for LED lighting fixtures mounted on poles for area lighting applications, the entire fixture must be replaced in order to change the shape and brightness. 
     SUMMARY 
     An example embodiment is directed to a modular light emitting diode (LED) fixture. The fixture includes a housing, a modular, removable LED module attached within the housing, and at least one modular, removable power supply attached to the housing for powering the LED module. 
     Another example embodiment is directed to a modular LED fixture which includes a housing and a plurality of individually removable PCB strips attached within the housing. Each strip has one or more LEDs thereon. The fixture includes at least one modular, removable power supply attached to the housing for powering the LEDs on the PCB strips. 
     Another example embodiment is directed to a modular LED fixture having a housing, a removable array of LEDs within the housing, and at least one modular, removable power supply attached within the housing for powering the LED array. The LED array and power supply are arranged in side-by-side relation within the housing. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Example embodiments will become more fully understood from the detailed description given herein below and the accompanying drawings, wherein like elements are represented by like reference numerals, which are given by way of illustration only and thus are not limitative of the example embodiments. 
         FIG. 1  is a bottom view of an example modular LED lighting fixture with power supplies. 
         FIG. 2  is a top view of the modular LED fixture in  FIG. 1  to illustrate visible heat spreading components. 
         FIGS. 3 and 4  illustrate side views of the modular LED fixture to illustrate the thin footprint from the LED fixture on a suitable support. 
         FIG. 5  is a detailed bottom view of the modular LED lighting fixture showing the LED light module in more detail. 
         FIG. 6  is a cross sectional view of a given LED module. 
         FIGS. 7A to 7G  illustrate types of roadway illumination. 
         FIG. 8  is a top view of an LED lighting package in accordance with an example embodiment. 
         FIG. 9  is a perspective view of the backing shown in  FIG. 8 . 
         FIGS. 10A-10F  show top views of alternative shapes for a cell shown in  FIG. 9 . 
         FIG. 11  shows a perspective view of the backing with a bottom flat panel attached thereon. 
         FIG. 12  shows a perspective view of a portion of the backing shown in  FIG. 11 . 
         FIG. 13  illustrates an LED module in accordance with another example embodiment. 
         FIG. 14  illustrates a slider bracket assembly used in the LED module of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     As used herein, the term “lens” or “window” may be understood as a device for either concentrating or diverging light, typically formed from a piece of shaped glass, polymer or plastic. For example, a lens as described herein may be embodied as a generally semi-spherical piece of shaped glass, polymer or plastic for concentrating or diverging light emitted from a light emitting die or LED assembly. A “flextape” as used herein may be understood as a polymer like film which in one high temperature example may be composed of a polyimide, i.e., a flexible polyimide circuit having at least one polyimide layer and at least one conductive layer within a flexible plastic resin. The conductive layer forms a metal trace connected to LED or LED assembly or array. 
     An LED package can be synonymous with an LED module for the following discussion. Additionally, the modular LED fixture including replaceable LED modules and power supplies may be applicable in general to area lighting applications, inclusive but not limited to street lighting, parking lot lighting and security lighting. 
     Example embodiments illustrating various aspects of the present invention will now be described with reference to the figures. As illustrated in the figures, sizes of structures and/or portions of structures may be exaggerated relative to other structures or portions for illustrative purposes only and thus are provided merely to illustrate general structures in accordance with the example embodiments. 
     Furthermore, various aspects of the example embodiments may be described with reference to a structure or a portion being formed on other structures, portions, or both. For example, a reference to a structure being formed “on” or “above” another structure or portion contemplates that additional structures, portions or both may intervene there between. References to a structure or a portion being formed “on” another structure or portion without an intervening structure or portion may be described herein as being formed “directly on” the structure or portion. 
     Additionally, relative terms such as “on” or “above” are used to describe one structure&#39;s or portion&#39;s relationship to another structure or portion as illustrated in the figures. Further, relative terms such as “on” or “above” are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if a device or assembly in the figures is turned over, a structure or portion described as “above” other structures or portions would be oriented “below” the other structures or portions. Likewise, if a device or assembly in the figures is rotated along an axis, a structure or portion described as “above” other structures or portions would be oriented “next to”, “left of” or “right of” the other structures or portions. 
     An example embodiment of the present invention is directed to a modular LED lighting fixture, where the shape and brightness of light output from the fixture can be altered by changing LED modules within the fixture and/or power supplies powering the modules in the fixture. In an example, a given LED module within the fixture includes one or more LEDs mounted on a carrier. Secondary optics or reflectors can be provided over and around the LEDs within the module to shape the total light output of the LED module. Different modules having different LEDs, optics and/or reflector arrangements for different light shapes can be interchangeable within a particular modular LED lighting fixture. 
     In another example, the light fixture includes interchangeable power supplies that drive the LED modules. The power supplies can be replaced (swapped out) in an effort to alter and/or adjust the brightness and/or performance characteristics of the fixture, depending on a desired application. 
     In one example, the modular LED lighting fixture is applicable to area lighting applications such as roadway street lights, parking lot lights and security lighting. However, the example embodiments are not so limited, as it would evident to one of skill in the art to use the example modular LED lighting fixtures in other lighting applications, such as within an office building, home, park or any place where it is desired to use most or all of the light output to illuminate an intended area, and not just a general area of interest. Roadway lights typically are located between 20-40 feet above a road and can be classified as any of Type I, II, III, IV or V, according to the shape of the light output. Accordingly, the example embodiments can provide a single modular LED lighting fixture mounted on a suitable structure above the area of interest which is easily alterable between the various types of lighting by swapping out the different LED modules. The brightness and/or performance of the modular LED lighting fixture can be adjusted by adding, subtracting and/or replacing power supplies therein. 
       FIG. 1  is a bottom view to illustrate an example modular LED lighting fixture with power supplies. These interchangeable power supplies include constant current drivers which supply a constant but adjustable current with a varying voltage. The voltage may vary depending on the number of LEDs used in giving LED modules of the lighting fixture. As the power supplies may also by modular, additional power supplies may be added, subtracted and/or replaced to modify the light output (brightness) and performance of the modular LED lighting fixture. 
     Referring now to  FIG. 1 , the modular LED lighting fixture  100  includes a fixture housing  110  which houses a power supply unit  120  and a removably attached LED module  130 . Specific details of the LED module  130  are not shown in  FIG. 1  for purposes of clarity. The fixture housing  110  may include a protective door  140  for protecting the power supply unit  120  from the environmental conditions. The door  140  may be made of a suitable metal such as aluminum and is connected at a set of hinges  145  to the fixture housing  110  via suitable fasteners, such as rivets or screws for example. 
     The LED module  130  is protected by a hinge able window  150  which may be made suitable glass or opaque material rimmed by an outer metal frame  155  and hinged at  157  to the fixture housing  110 . The fixture housing  110  includes an opening  160  for receiving a support  170 . An example of the support  170  may be a street light pole, or any other supporting structure to secure the modular LED fixture  100  in place. 
     The power supply unit  120  may be secured to an interior surface of the fixture housing  110  with suitable fasteners such as screws, so as to be easily removable. The power supply unit  120  may be switched out and replaced with any other power supply unit, of any size, so long as it fits within the footprint of the space available within the fixture housing  110 . 
     The power supplies may be constant current drivers which supply constant but adjustable current with variable voltage, depending on the number of LEDs. For example, a suitable power supply may be a switch mode, switching LP 1090 series power supply manufactured by MAGTECH, such as the MAGTECH LP 1090-XXYZ-E series switchmode LED driver, for example. The driver has an adjustable voltage range and the type of driver depends on the voltage drop of each of the LEDs in series in the LED matrix. 
       FIG. 2  is a top view of the fixture  100  with visible heat spreading components. Referring to  FIG. 2  and looking at a top side of the fixture  100 , a plurality of fins  165  also known as heat spreading T-bars may be provided with channel spacings there between to facilitate thermal dissipation. In one example, these fins  165  may be formed as part of a single cast modular fixture housing  110 . The fixture housing  110  may be made of a suitable material providing a heat sinking or heat spreading capability, such as aluminum, ceramic and/or other materials. 
       FIGS. 3 and 4  illustrate side views of the modular LED fixture to illustrate the thin footprint from the LED fixture on a suitable support  170 . As shown in  FIGS. 3 and 4 , the widest portion at junction  180  where the support  170  meets the fixture housing  110  has a thickness of 3 inches. The fins  165  have a height of 1 inch and the thin portion  168  of the fixture housing  110  has a width cross sectional height of 1 inch, for a total thickness of two inches. The cross sectional thickness at the widest part of fixture housing is 3′. The fins  165  have a thermal surface area of 240 in 2 , and the remainder of fixture housing  110  provides another 120 in 2  thermal surface area to dissipate heat generated by the LEDs  135 . In an example, the LED module  130  consumes at least 90 W of power. The thin cross-section provides a fixture  100  that has a small, narrow footprint, but which is capable of high-power, high-performance lighting applications. 
       FIG. 5  is a detailed bottom view of the modular LED lighting fixture  100  showing the LED light module  130  in more detail. In  FIG. 5  the door  140  and window  150  have been removed for purposes of clarity. As shown in  FIG. 5 , the LED module  130  includes one or more LED lamps  135 . The LEDs  135  are mounted on printed circuit board (PCB) strips  138 , which in turn are attached to a suitable backing plate (not shown), which may be made of a suitable thermally conducted material such as copper, for example. The strips  138  of LEDs  135  may be secured to an interior surface of the fixture housing  110  with suitable fasteners such as screws, so as to be easily removable. One, some or all strips  138  may be switched out and replaced with any other strips  138 , of any size, so long as it fits within the footprint of the space available for the LED module  130  within the fixture housing  110 . In an alternative, a backing plate supporting all strips  138  of the module  130  may be may be secured to an interior surface of the fixture housing  110  with suitable fasteners such as screws, so as to be easily removable. The entire LED module  130  may be switched out and replaced with another LED module  130 , of any size, so long as it fits within the footprint of the space available within the fixture housing  110 . 
     The LEDs  135  may be configured to emit any desired color of light. The LEDs may be blue LEDs, green LEDs, red LEDs, different color temperature white LEDs such as warm white or cool or soft white LEDs, and/or varying combinations of one or more of blue, green, red and white LEDs  135 . In an example, white light is typically used for area lighting such as street lights. White LEDs may include a blue LED chip phosphor for wavelength conversion. 
     One, some or all LEDs  135  in LED module  130  may be fitted with a secondary optic that shapes the light output in a desired shape, such as circle, ellipse, trapezoid or other pattern. The embodiment in  FIG. 5  illustrates a fixture  100  which may be operate in the 70 to 150 watt range with a total of 90 individual LEDs  135  on eighteen (18) PCBs  138  of the module  130 . Also, shown in  FIG. 5  are the power supply unit  120  and the opening  160  for receiving the support  170 . 
     In an example, the mounting surface area for LED module  130  within fixture housing  110  can be up to about 90 in 2 , based on the dimensions of the example fixture  100 . The average lumen output depends on the rating of LEDs  135  within LED module  130 . In an example, each of the LEDs  135  can have an average light output in a range of between 70-90 lumens, which enables the fixture  100  to be able to generate a total lumen output in a range between about 6300 to 8100 lumens. For the LED module  130 , the light output per square inch of module  130  surface area can be in a range of about 70 to 90 lumens/in 2 . However, it would be evident to the skilled artisan that the fixture  100  could be configured to generate a total light output less than 6300 lumens or greater than 8100 lumens, based on the configuration of LEDs  135  in the LED module  130  therein. 
       FIG. 6  is a cross sectional view of a given LED module  130 . In  FIG. 6  two LEDs  135  are shown, it being understood that any number of LEDs may be provided in a array of LEDs for example (i.e., serial columns in parallel). The LEDs  135  may be mounted on a printed circuit board  138  that is mounted onto a copper backing (plate or sheet)  139 . The backing  139  may be used to help spread heat generated by the LEDs  135  and to compensate for thermal resistance between components of the LED module  130 . It is understood that materials with good thermal conductivity other than copper may also be used such as silver, alloys of copper or silver or other metal materials having high thermal conduction properties. In  FIG. 6 , each group of five (5) LEDs  135  can be mounted to a five-inch long PCB strip  138 , with each PCB strip  138  adhered to the removable copper sheet via a suitable thermal epoxy or paste. 
     Referring to  FIG. 5 , the shape of the module  130  is irrelevant; it can be trapezoidal, oval, square, rectangular, circular, etc. so long as it fits within the footprint of the fixture housing  110 . Additionally, the type of power supply used does not matter, and a suitable variable power supply such as the LP 1090 may be automatically variable between 90 and 240 volts depending on the particular application of the modular LED lighting fixture  100 . 
     As for the individual LEDs  135  of the module  130 , the LEDs  135  may be slanted at different angles, at the same angles, in groups of angles which differ from group to group, etc. For example, in an area lighting application, the shape of the light output may be varied by the angle of the LEDs from normal, the shape or orientation of the module  130  with LEDs thereon so as to provide a single modular LED lighting fixture  100  which may be altered from any of Types I, II, III, IV or V roadway classifications by swapping out differently configured LED modules  130 . 
     Accordingly, for a given LED module  130 , one, some, or all strips  138  or groups of strips  138  having LEDs  135  thereon can be mounted at different angles to the planar, bottom surface of the fixture housing  110 . Additionally, a given strip  138  may be straight or curved, and may be angled with respect to one or more dimensions. In another example, each LED  135 , groups or strips  138  of LEDs  135  constituting the LED module  130  may include the same or different secondary optics and/or reflectors. In other examples, the groups or strips  138  of LEDs  135  for a given LED module  130  may be mounted at varying ranges of angles, and different optical elements or no optical elements may be used with the groups or strips  138  of LEDs  135  mounted at differing ranges of angles. The angles of the LED strips  138  and/or LEDs  135  with or without optical elements can be fixed or varied in multiple dimensions. Therefore, one or more strips  138  of LEDs  135  constituting LED module  130  can be set at selected angles (which may be the same or different for given strips  138 ) to the bottom surface of the fixture housing  110 , so as to produce any of IESNA-specified Type I, Type II, Type III, Type IV and Type V roadway illumination patterns. 
     Example configurations of angled LEDs  135  or angled strips  138  of an LED module  130  are described in detail in co-pending and commonly assigned U.S. patent application Ser. No. 11/519,058, to VILLARD et al, filed Sep. 12, 2006 and entitled “LED LIGHTING FIXTURE”, the relevant portions describing the various mounting angles of strips  138  and/or LEDs  135  being hereby incorporated in its entirety by reference herein. 
     Further as discussed above, brightness and performance of the LED lighting fixture  100  may also be adjusted by adding, subtracting or replacing its power supply unit  120 . In a particular example, the LED module  130  may have a trapezoidal shape with 15 LEDs  135  on each side except the backside, and oriented at a 25° angle from normal utilizing oval optics. This provides a 50° angle from normal for a desired lighting application 
     In another example, the LEDs  135  may be mounted to a flextape with a bond wire electrically connecting the flextape to each of the LEDs  135 . The flextape may be adhered to the copper backing  139  in  FIG. 6  or directly to the housing  110 . This permits orientations or shapes of the copper backing  139  or housing  110  other than flat or planar, which may also facilitate desired angles of inclination of the LEDs  135  from normal for desired light output from fixture  100 . Details of the flextape are described in commonly-assigned U.S. patent application Ser. No. 11/476,836, filed Jun. 29, 2006 to Peter Andrews and entitled “LED PACKAGE WITH FLEXIBLE POLYIMIDE CIRCUIT AND METHOD OF MANUFACTURING LED PACKAGE”, the relevant portions describing the flextape being hereby incorporated in their entirety by reference herein. 
     The flextape may include multiple layers, such as a metal trace (conductive layer) between two polyimid layers. The layers may include a polyimid layer of flexible plastic resin. Polyimid material is a synthetic polymeric resin of a class that is resistant to high temperatures, wear and corrosion. Polyimid materials have been used primarily as a coating or film on a substrate substance and are electrically insulating materials. 
     The metal trace may be formed of copper, silver, alloys thereof of copper or silver or other metal materials having high electrical conduction properties. The flextape may be coated with SnPb or Pb to facilitate soldering of the bond wire to the LED to the flextape. A high temperature solder such as Sn, AgSn, AuSn, etc. may be used as the soldering agent, for example. Another way to connect the flextape may be by wirebonding. 
     The use of flextape may facilitate the manufacturing process as compared to conventional manufacturing techniques. The flextape, due to its constituent component construction, can withstand relatively high temperatures (i.e., 300° C.) without damage. Accordingly, during the manufacturing process, a high temperature solder (such as Sn, AgSn, AuSn, etc.) can be applied to flextape, copper plate, LED, or to any combination of these components. 
     The flextape may include multiple, intricate circuitry and metal trace patterns for applications where it may be desirable to use multiple, different LEDs  135  of the module  130  (e.g., multiple colors such as red, green, and blue). Furthermore, these complex patterns may be relatively easy and cost effective to implement using existing flextape techniques. A flextape having complex patterns may enable the manufacture of LED modules  130  having sophisticated functions at a minimal increase in cost. This may be due in part to the fact that flextape may be manufactured in mass using a reel-to-reel production technique, for example. 
     In another example, the modular LED lighting fixture  100  may include a backing sheet of thermally conductive material and an array of LEDs  135  to form a LED module or package as described in co-pending and commonly assigned U.S. patent application Ser. No. 11/379,726 to Russ Villard, filed Apr. 21, 2006 and entitled “LED LIGHTING FIXTURE WITH IMPROVED HEATSINK”, the relevant portions of which are hereby incorporated in their entirety by reference herein. 
     The term “array of LEDs” as used herein means a module  130  of one or more LEDs  135  in various configurations and arrangements. The backing plate includes a cell structure. The cell structure includes a plurality of hollow cells contiguously positioned in a side by side manner. The array of LEDs  135  is mounted to a printed circuit board (PCB). The PCBs for the two or more arrays may be attached to the cell structure to balance heat dissipation and color uniformity of the LEDs. 
       FIG. 8  shows a top view of a light emitted diode (LED) lighting package  200  described in the in accordance with the present invention. The LED lighting package  200  may be used in the fixture  100  and includes a backing  210  of thermally conductive material such as aluminum due to its abundance and inexpensive cost, although other thermally conductive materials such as copper, ceramics, plastics, and the like may be utilized. In this example, the LED lighting package  200  includes four columns of LEDs  135 . Each column in this example may include at least two printed circuit boards (PCB) such as PCB  220 A and  220 B. On each PCB, at least five LEDs, such as LED  135  are mounted and electrically connected in series with each other, it being understood that more or less LEDs could be serially mounted. In this example, the total number of LEDs  135  in LED lighting package  200  is forty. 
     Each PCB  220 A/B includes a positive voltage terminal and a negative voltage terminal (not shown). The negative voltage terminal of PCB  220 A is electrically connected to the positive voltage terminal of PCB  220 B so that the ten LEDs defining a column are electrically connected in serial. Although two PCBs are shown to construct one column of LEDs, a single PCB may also be utilized for a particular column of LEDs. Each column of ten LEDs is electrically connected in parallel to its adjacent column over wires  230 A-D and are equally spaced at a distance d measured in the horizontal direction from the center of adjacent LEDs. For example, the distance, d, in  FIG. 8  may be approximately 2.4 inches, although other dimensions are possible. In the vertical direction, the LEDs are equally spaced at a distance, v, where v may be approximately 1 inch, although other dimensions are possible. The backing  210  may be anodized white aluminum to reflect the light emitted from the LEDs. 
       FIG. 9  is a perspective view of one embodiment for the backing  210  shown in  FIG. 8  in accordance with the present invention. Backing  210  includes an aluminum panel  405  fixedly attached to a cell structure  415 . The cell structure  415  is composed of a plurality of hexagonally shaped hollow cells such as cell  410  contiguously positioned in a side by side manner. Cell structure  415  has substantially the same length and width dimensions as the aluminum panel  405 , so as to align the edges of aluminum panel  405  with the edges of cell structure  415 . 
     The aluminum panel  405  may be suitably attached to cell structure  415  utilizing a thermal epoxy such as Loctite® 384. Although aluminum is the example thermally conductive material, that other thermally conductive material such as graphite may also be utilized. When light is emitted from LEDs  420  affixed to the printed circuit boards (PCBs) PCBs  220 A and  220 B, heat is dissipated through the aluminum panel  405  and the surface area of the hexagonally shaped cells. 
       FIGS. 10A-10F  show top views of alternative shapes for cell  410  according to the present invention.  FIG. 10A  shows a top view of a circular cell  510 .  FIG. 10B  shows a top view of an elliptical cell  520 .  FIG. 10C  shows a top view of a square cell  530 .  FIG. 10D  shows a top view of a pentagonal cell  540 .  FIG. 10E  shows a top view of an octagonal cell  550 . It is recognized that other cell shapes may be utilized for cell structure  415 .  FIG. 10F  shows a top view of a cell  560  composed of concentric circles. It is recognized that other cell shapes may be utilized for cell structure  415 . The cell shapes of  FIGS. 10A-F  may be contiguously arranged on a side-by-side basis to form a cell structure suitable for an alternative cell structure  415 . 
       FIG. 11  shows a perspective view of an alternative backing arrangement  600  in accordance with the present invention which may be suitably employed as the backing  210  in  FIG. 8 . Backing arrangement  600  includes a top flat panel  605  attached to a cell structure  615  in a manner similar to  FIG. 9 . Optional bottom flat panel  620  is attached to the bottom of cell structure  615 . The optional bottom flat panel  620  has substantially the same dimensions as flat panel  605  and is fixedly attached to the cell structure  615 . Bottom flat panel  620  may be employed to address lighting applications requiring a flat surface in back of a lighting package such as display models where the bottom flat panel  620  of a lighting package such as lighting package  300  is utilized when mounting the lighting package to a structure such as a wall or stanchion. 
       FIG. 12  shows a perspective view of a portion of an alternative backing  700  in accordance with the present invention. In backing  700 , cell structure  705  is composed of a plurality of hexagonally shaped hollow cells. Cell structure  705  includes a series of ten bores drilled in both the x and y direction transverse to the hexagonally shaped hollow cells. Each bore such as bore  710  has a given diameter, such as a ⅛ inch diameter. The separation between adjacent bores may be approximately 1 inch on center, for example. It is recognized the number of bores which are drilled are dependent on the diameter of each bore. Consequently, more bores may be drilled that have smaller diameters. Additionally, it is recognized that varied diameters of bores may alternatively be utilized. 
       FIG. 13  illustrates an LED module  130  in accordance with another example embodiment, and  FIG. 14  illustrates a slider bracket assembly  1400  used in the LED module  130  of  FIG. 13 . The LED module  130  may be attached within the fixture housing  110  as shown in  FIGS. 1 and 5 , for example. The LED module  130  comprises a plurality of LEDs  135  mounted on PCB strips  138 ′, which in turn adhere or are mechanically coupled to a plurality of slider bracket assemblies  1400 . Each slider bracket assembly  1400  comprises a movable slider bracket  1410 , which in an example has an inverted U-shape, and a fixed slider bracket support  1420 , which in an example has a corresponding inverted U-shape. 
     The slider bracket assembly  1400  may be mounted on a surface of fixture housing  110  with a thermal epoxy, for example, or by mechanical means. Thermal grease may be utilized in the slider mechanism between the movable bracket  1410  and fixed bracket  1420  shown in  FIG. 14  to facilitate the sliding movement of movable bracket  1410  on the fixed bracket  1420 . With the LEDs  135  mounted on PCB strips  138 ′, which in turn are affixed to corresponding movable brackets  1410 , the sets of LEDs  135  can be unplugged and slipped out for ease of replacement or upgrade. 
     In an example, up to 10 LEDs  135  can be serially mounted on a PCB strip  138 ′ affixed to a top surface of a movable bracket  1410 , up to at least approximately a 45° with the planar surface of fixture housing  110 . This is due to the U-shape of the sliding mechanism of the bracket assembly  1400 . In an example, the bracket assembly  1400  can be a SIOUX CHIEF™ 12-19 inch long slider bracket made of copper clad galvanized materials. However, other materials could be used as is known in the art. 
     The example embodiments of the present invention being thus described, it will be obvious that the same may be varied in many ways. For example, the flextape may be embodied other than as a polyimid polymer film. In one example, the application of a polyimid such as PYROLUX® by DuPont may be sprayed on a metal substrate (backing) of a suitable thickness, (such as 2 μm thick). A leadframe such as copper (Cu) may be used for the metal traces and die attach platform. The top of the flextape could be insulated or not depending on needs/desires of the application or LED. Additionally, the polyimid could be etched as desired into a “flex-print” type lead configuration and applied to a heat sink. 
     Such variations are not to be regarded as departure from the spirit and scope of the example embodiments of the present invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.