Abstract:
The present invention relates to a new method, system and apparatus for light emitting diode (LED) packages. An object of the present invention is to provide an LED package having reduced components, a superior heat dissipation property and a compact structure, does not largely restrict use of conventional equipment for its manufacture, and is compatible with implementation within present illumination devices packaging.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to co-pending U.S. Provisional patent application Ser. No. 61/725,191 titled “LED Spirit System”, filed on Nov. 12, 2012 the disclosure of which is herein incorporated by reference in its entirety, U.S. Provisional patent application Ser. No. 61/725,196 titled “LED Spirit Connector System”, filed on Nov. 12, 2012, U.S. Provisional patent application Ser. No. 61/737,422 titled “LED Stick, Strings, Straw and/or Chain Manufacturing Method”, filed on Dec. 14, 2012, U.S. Provisional patent application Ser. No. 61/737,437 titled “LED Fluid Cooling Assembly”, filed on Dec. 14, 2012, and U.S. Provisional patent application Ser. No. 61/737,459 titled “LED Stick, Strings, Straw and/or Chain Phosphor Coating System and Method” filed on Dec. 14, 2012. 
     
    
     PATENTS CITED 
       [0002]    The following documents and references are incorporated by reference in their entirety, Ogawa et al (U.S. Pat. No. 7,714,346), Kang et al (U.S. Pat. No. 7,642,563), Mok et al (U.S. Pat. No. 7,262,438) and Zykin (U.S. patent application Ser. No. 13/313,129). 
       FIELD OF THE INVENTION 
       [0003]    The present invention relates to Light Emitting Diodes (LEDs) mounting within electrical and mechanical structures, and in particular to devices, systems and methods for the efficient and inexpensive removal of heat from the LEDs in LED light fixtures. 
       DESCRIPTION OF THE RELATED ART 
       [0004]    LEDs promise to revolutionize illumination, through their ultra efficient conversion of energy into visible light. Within a decade, we have gone from illumination provided by a 60 W incandescent light bulb being replaced by a 13 W Compact Fluorescent Light bulb (CFL) to a 3 W LED light bulb. In effect, reducing by over 90% the consumption required for similar illumination. The above is not only important because it saves energy, but also because now we can illuminate the world without the need to electrify the world. 
         [0005]    An LED is an element in which electrons and holes are combined in a P-N semiconductor junction structure by application of current thereby emitting certain types of light. LEDs are typically formed to have a package structure, in which an LED chip is mounted on a mechanical carrier, frequently referred to as an “LED package.” Such an LED package is generally mounted on a printed circuit board (PCB) and receives current applied from electrodes formed on the PCB to thereby emit light. 
         [0006]    In general illumination applications, engineers have discovered the importance of generating light in a 360 deg. envelope, not unlike the way in which an incandescent filament illuminates. To accomplish such goals, a new type of package termed an LED sticks or LED straw has been created. In it, individual LEDs are serially placed along a thin sleeve or slice of material, typically made of a sapphire or ceramic material. The stick is powered from each end, creating a stick of light. 
         [0007]    In an LED package, heat generated from the LED chip has a direct influence on the light emitting performance and life span of the LED package. When heat generated from the LED chip is not effectively removed, dislocation and mismatch occur in a crystal structure of the LED chip. In effect, brightness is related to power applied, so a large amount of heat is generated in an LED chip due to the high currents, heat that must be typically transferred to a heat sink, typically, a separate device for effectively dissipating the generated heat is required. 
         [0008]    LEDs are typically mounted on printed circuit boards (PCBs), which are used to mechanically support and electrically connect the LEDs to electronic drivers (power supplies, amplifiers, etc.) using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. This substrate is typically a dielectric or insulator. Some of these dielectrics include Teflon, FR-4, FR-1, CEM-1 or CEM-3. 
         [0009]    The above has a significant limitation, the thermal transfer from the LED package to the heat sink, is going through a plastic, not the optimal way in which to efficiently transfer heat. What is needed, is a way in which to mechanically support and electrically connect the LED package to a heat sink with the highest efficiency possible. 
       SUMMARY OF THE INVENTION 
       [0010]    This section is for the purpose of summarizing some aspects of the present invention and to briefly introduce some preferred embodiments. Simplifications or omissions may be made to avoid obscuring the purpose of the section. Such simplifications or omissions are not intended to limit the scope of the present invention. 
         [0011]    In one aspect the invention is about an LED light source system comprising two or more LED packages connected in series forming an LED chain so that each individual LED package within said chain has one or more electrical contacts formed along opposite sides of said package side, said electrical contacts electrically and mechanically connected along the length of said chain between neighboring LED. In another aspect one or more of the LED packages forming said chain has said package upper and/or lower LED lead bent and formed as a clip, clamp or spring along all or portion of said lead length. In yet another aspect the initial LED package located at said chain near end, and the final LED package located at said chain distal end are connectable to a power source. In another aspect said LED chain is inserted into a container shaped as a tube and secured within said tube by said LED leads. In yet another aspect, said LED leads are secured to slots within said tube interior. In another aspect said LED chain is inserted into a container shaped as a bulb or lamp. 
         [0012]    In one aspect, two or more of said LED chains are concatenated to form a supra chain. In another aspect, said supra chain is inserted into a container shaped as a tube and secured within said tube by said LED leads. In one aspect, said LED leads are secured to slots within said tube interior. In yet another aspect, said LED chain is inserted into a container shaped as a bulb or lamp. 
         [0013]    In one aspect the invention is about an LED light source matrix comprising two or more LED packages connected in series forming an LED chain so that each individual LED package within said chain has one or more electrical contacts formed along opposite sides of said package side, said electrical contacts electrically and mechanically connected along the length of said chain between neighboring LED and within two or more neighboring rows of said LED chains, wherein at least one said LED package occupying the same respective column position within said matrix has at least one of said package upper and/or lower LED lead connected to its respective counterpart above or below it within said matrix. In another aspect, said LED matrix is inserted into a container shaped as a bulb or lamp. In yet another aspect one or more of the LED leads from said LED matrix first and last rows are appropriately shaped and inserted into a container shaped as a bulb so that said LED leads can secure said matrix within said bulb interior. In another aspect said LED matrix is inserted into a container shaped as a tube and secured within said tube by said LED leads. In yet another aspect said LED leads are secured to slots within said tube interior. In another aspect one or more of the LED leads from said LED matrix first and last rows are appropriately shaped and thermally connected to a heat sink, then inserted into a container shaped as a tube so that said LED leads can secure said matrix within said tube interior. 
         [0014]    In one aspect, the invention is about a method for manufacturing an LED light source system, said method comprising configuring two or more LED packages connected in series forming an LED chain so that each individual LED package within said chain has one or more electrical contacts formed along opposite sides of said package side, said electrical contacts electrically and mechanically connected along the length of said chain between neighboring LED and ensuring that one or more of the LED packages forming said chain has said package upper and/or lower LED lead bent and formed as a clip, clamp or spring along all or portion of said lead length. In another aspect it further comprises configuring the initial LED package located at said chain near end, and the final LED package located at said chain distal end are connectable to a power source. In one aspect, the invention comprised inserting said LED chain into a container shaped as a tube and secured within said tube by said LED leads. In one aspect the method comprises ensuring said LED chain when inserted into a container shaped as a tube and secured within said tube by said LED leads. In one aspect the method further comprises inserting said LED leads securely to slots within said tube interior. 
         [0015]    Other features and advantages of the present invention will become apparent upon examining the following detailed description of an embodiment thereof, taken in conjunction with the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIGS. 1-4  show some prior art illustrations for LED technology. 
           [0017]      FIGS. 5-11  show illustrations of the improved LED mechanical/electrical packaging options, according to exemplary embodiments of the invention. 
           [0018]      FIGS. 12-15  show illustrations of LED packaging options, according to exemplary embodiments of the invention. 
           [0019]      FIGS. 16-41  show illustrations of improved mechanical/electrical/heat dissipation options, according to exemplary embodiments of the invention. 
       
    
    
       [0020]    The above-described and other features will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0021]    To provide an overall understanding of the invention, certain illustrative embodiments and examples will now be described. However, it will be understood by one of ordinary skill in the art that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the disclosure. The compositions, apparatuses, systems and/or methods described herein may be adapted and modified as is appropriate for the application being addressed and that those described herein may be employed in other suitable applications, and that such other additions and modifications will not depart from the scope hereof. 
         [0022]    Simplifications or omissions may be made to avoid obscuring the purpose of the section. Such simplifications or omissions are not intended to limit the scope of the present invention. All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinence of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art. 
         [0023]    As used in the specification and claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a transaction” may include a plurality of transaction unless the context clearly dictates otherwise. As used in the specification and claims, singular names or types referenced include variations within the family of said name unless the context clearly dictates otherwise. 
         [0024]    Certain terminology is used in the following description for convenience only and is not limiting. The words “lower,” “upper,” “bottom,” “top,” “front,” “back,” “left,” “right” and “sides” designate directions in the drawings to which reference is made, but are not limiting with respect to the orientation in which the modules or any assembly of them may be used. 
         [0025]    It is acknowledged that the term ‘comprise’ may, under varying jurisdictions, be attributed with either an exclusive or an inclusive meaning. For the purpose of this specification, and unless otherwise noted, the term ‘comprise’ shall have an inclusive meaning—i.e. that it will be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components or elements. This rationale will also be used when the term ‘comprised’ or ‘comprising’ is used in relation to one or more steps in a method or process. 
         [0026]    Referring to  FIGS. 1-4 , we see the traditional lead frames or lead LED frames  100 , which are used today to distribute and ship LED packages  102  (said packages comprised of both lensed LED packages and non-lensed ones) throughout the industry. These frames consist of a lattice  106  having one or more orthogonal horizontal  108  and vertical  110  members that hold the LEDs in place, and are used for shipping from LED mfr. to the LED light fixture assembly mfr. 
         [0027]    At the light fixture mfr. site, the LEDs  102  are cut off from the frame strips lattice members  108 ,  110  and become loose, independent, individual light-emitting diodes LEDs  102 . During manufacturing, the LEDs  102  are then soldered onto a printed-circuit board (PCB)  402 . 
         [0028]    The above has a large number of disadvantages, one of the primary ones being the fact that the already aligned and prepositioned LEDs  102  are loosened, before being re-attached to the PCB  402 . This step requires machinery to align and position the LEDs  102 . The proposed solution described here is to completely eliminate the PCB  402  used to position the LEDs  102  by making certain changes to the Lead LED Frame (LLF)  100  when manufacturing the LEDs  102 . In the traditional method the LEDs  102  are first stamped out, pressed from plastic, electrical and other holders made, crossing points, etc. cut off and then the LEDs are created, then cut off from the frame  100 , sorted, aligned and then soldered to PCB. 
         [0029]    Referring to  FIGS. 5-11 , we see the present lead frame arrangement  502  vs. the proposed new  602  LED connector or chain and manufacturing method in a proposed embodiment. In the present method (intended for a PCB line), one or more LED  102  electrical contacts are formed on either side of the LED package  102  (side one  504  and side two  506 ). These are the electrical leads used to power the LED, which are later bent for surface mount attachment to the PCB). The LED is held to the frame by the LED holders  508 ,  510  which are usually on two remaining sides of the LED package. These are used to hold the LED package to the lead frame, and are later cut-off after the LED  102  is manufactured. 
         [0030]    In one embodiment of the present invention  602 , the LEDs  102  are rotated 90 degrees in the design for the forming machine, so that the one or more electrical contacts  604 ,  606 ,  608 ,  610 ,  612 ,  614  are formed along each side forming the rows of the lead frame (and between neighboring LEDs), and the LED holders  508 ,  510  (not electrically connected to the LED) are extended along the column to provide support for the inner members. In one embodiment, the LEDs  102  are connected as a long single-pearl string  902 , by a joint  904  between each LED  102 . 
         [0031]    Power is applied at one end, and flows along the row to power each LED  102  by a suitable power source. After so many LEDs, the LED chain may require electrical ending. However a light fixture formed by a chain of LED chains (say a supra chain) formed by the mechanical linkage of two or more LED chains, with separate electrical power connections going to the various LED chains integrating the supra chain. If required, resistors and other components may be stamped along each or every so many of the LEDs  102  joints  904 . 
         [0032]    In another embodiment, the individual LEDs  102  are assembled or stamped into a two dimensional matrix  702  in which the rows  704 ,  706 ,  708  share the power connections (an LED matrix formed of LED chains). As before, the connections between neighbors along the rows are connected through traditional metal stamping techniques, and may include resistors and other components placed at either the ends or after a number of LEDs. The electrical power connection is attached at either end of a number of LEDs on a column, and daisy chained along the row of the matrix. Resistors such as these are typically used as current limiters to prevent against overdriving of the electronics. Within the columns (i.e. up/down), the LED leads are left uncut, so that within two or more neighboring rows of said LED chains, at least one said LED package occupying the same respective column position within said matrix has at least one of said package upper and/or lower LED lead connected to its respective counterpart above or below it within said matrix. 
         [0033]    As before, for electrical reasons the above matrix may be powered column-wise (with the power supply connected along the LED&#39;s occupying the first and last columns), or as a supra chain (where the end of each matrix row) is electrically connected to the beginning of another row within the column. Said LED matrix may then be bent into tube, squares or any other suitable shape. 
         [0034]    In one embodiment, the LED holder leads  508 ,  510  (described as upper and lower in reference to the left/right of the power connectors within each LED package) are not cut or clipped, but instead formed as clips, clamps and/or springs along its length or at/near their end  710 ,  712  so as to mechanically and thermally attach the LEDs to the heat sink  1000 . While electrically isolated through either special coatings or encapsulation, they are thermally connected to the LED  102  package, so that efficient, metal-to-metal heat transfer channels are provided. Note a further advantage of this approach, is that these holder leads  508 ,  510  act as radiating heat sinks. 
         [0035]    For non-open collector diodes, the above allows for the voltage connections  602  (as well as  604 ,  606 ,  608 ,  610 ,  612 ,  614  and any others) to be held above the datum plane of any heat sink, allowing for the insulation of air to keep voltages from mixing or short-circuiting. Such an approach affords the opportunity to build an electrically connected electrical lead frame with no PCB that is capable of operating in a similar way. In an alternate embodiment, the electrical insulation of the voltage channels ( 714 , 716 ) is accomplished by elevating these above the datum of the heat sink  402 . 
         [0036]    In alternate embodiments ( FIGS. 12-13 ) such a linear ‘necklace’ or LED strip  1202  is formed when all LEDs  102  are connected through traditional technological interconnectors and holders capable of manufacturer through traditional precise micro-molding injection. In one such embodiment, an encapsulated electrical connection  1204  instead of the PCB carries out the electrical interconnections and mechanical holders between LEDs  102 . In such a connection there is no soldering, and all connections represent monolithic, isolated electrical links within an insulated housing. 
         [0037]    The plastic housing  1302  of the LED  102  may be configured so that the snap-on of the plastic creates the electrical connections between LEDs  102 , which greatly increases reliability and durability of contacts between packages  1304 ,  1306 ,  1308 , transitional electro resistance decreases because of no soldering points. 
         [0038]    Referring to  FIGS. 14-15 , we see the difference between the LED  102  package attached to the PCB or heat sink  402  by solder  1402 , versus the new approach wherein in one embodiment, the connection between the various LED packages  102  is accomplished by wires  1502 . Of critical importance is the fold in the connection between LEDs, which is formed as a S or Z or fold in one embodiment, allowing flexible bending of the connection between LEDs. 
         [0039]    Referring to  FIGS. 16-17  we illustrate a PCB-less system as part of a fluorescent bulb replacement for the T-5 and T-8 bulb standards. As can be seen, the LEDs may be arranged linearly or in matrix form. It should be noted that the lack of a PCB provides for a much wider angle of light (as the PCB does not cause a shadow). 
         [0040]    Referring to  FIGS. 18-21 , we see an embodiment where three or more parallel strips  1802  of LEDs are formed into an LED matrix that may be then shaped cylindrical form or LED roll  1902  and powered from one end to the other. The flexibility stated before, can be appreciated in an embodiment where the LED roll  1902  is fitted inside the body of a traditional light bulb or lamp volume  2202  ( FIG. 22 ) is used to provide Omni-directional light. In an alternate embodiment ( FIGS. 23-24 ), the LED roll is shaped as a tapered cone, improving the light distribution. 
         [0041]    In an alternate embodiment ( FIG. 25 ), a flexible matrix lattice arrangement  2502  is curved to fit within the contour of the bulb, lamp or a linear package. Note the driving electronics may be located within the base of the bulb  2504 . 
         [0042]    In an alternate embodiment ( FIG. 26 ), the LED roll  1902  is formed and inserted within a tube (such as a T-5/T-8 or other similar extended tube), so that they may replace a fluorescent tube within such a light fixture. In one an alternate embodiment ( FIG. 27 ), one or more strips  1802  are inserted within one or more slots  2702  built into said tube  2704  or they may be formed into a LED tube or cylinder  1902  and then inserted into the enclosure tube  2704 . 
         [0043]    Said enclosure tube may have the aforementioned slots  2702 . Note that in all enclosure cases, i.e. bulbs, lamps or the T-5/T-8 tubes  2704 , there could be introduced into the enclosure space a gas mix. Besides a gas mix, the complete lighting package may be immersed in a cooling fluid, which may be a dielectric to preserve electrical integrity while providing cooling. Such fluids may include inert gases. 
         [0044]    Referring to  FIGS. 28-29 , we see a single strand LED chain  1202  which in one embodiment we mount to a mechanical strip  2802  with a series of openings that match those of the string  902 . The strip acts as both a mechanical holder, and a heat transfer device for the LED packages. 
         [0045]    When used in a T-5 or T-8 fluorescent bulb replacement fixture, the ends of the strip  2802  are bent (in one embodiment as an ‘S’, ‘Z’, or any other “spring” form  3002 , in order to form a compression spring insert, so that when the strip  2802  is slid within the housing of said tube  2704  it forms a constant and efficient metal-to-metal heat transfer medium to the housing, which acts here as the heat sink. Note that in effect, as mentioned before, the strip  2802 , the spring  3402  and insert legs  3404  act themselves as radiators. 
         [0046]    When using open-emitter LEDs, it becomes necessary to electrically insulate the bottom of the LED package  904  making contact with the heat sink  3002 . One solution would be the addition of a simple FR4 sheet or other electrical insulator ‘sandwiched’ between the bottom of the LED and the heat sink. The different heat transfer rates would be accounted for by the sliding, as there would be no wave solder joints at the LED to crack. 
         [0047]    In another solution, as discussed in Zykin (U.S. patent application Ser. No. 13/313,129) and incorporate herein in its entirety trough reference, a base  2902  incorporating a layer of a material such as CERATOM  912  could be used. Acting as an efficient heat conducting dielectric, this would ensure efficient heat transfer to the heat sink  3002  and any fins or radiators attached thereto. 
         [0048]    In another embodiment  FIGS. 32-33 , the LED matrix or grid is held above the heat sink, using only the edge  3202  connections to transfer the heat, resulting in an inexpensive, non-PCB solution. In all cases, the complete lighting package may be immersed in a cooling fluid, which may be a dielectric to preserve electrical integrity while providing cooling. This may include inert gases. 
         [0049]    Referring to  FIG. 34  we see an alternate embodiment where two or more LED strips  1802  are placed one over the other (forming a bottom LED strips  3406 , in one embodiment with lensed LEDs, although in an alternate embodiment they may not need the lensing), the strips of LEDs may then be inserted into a suitably modified T-5, T-8 or other suitable enclosure tube  2704 . Said enclosure tube may have the aforementioned slots  2702  or be smooth and have the leads  3402  from the LED strips  1802  bent so they extend outside of the strips without significantly occluding the light emitted from the LEDs. Thus in addition to serving as a thermal radiator, they mechanically support the LED strips  1802  within the enclosure tube  2704 . 
         [0050]    Referring to  FIGS. 35-37 , the coating of yellowing phosphor described above may be applied near the periphery of the encapsulation  3502 , above the actual LED die area  3602  or directly above the LED die on a traditional package  3702 . 
       Example 1 
       [0051]    An LED light emitting bar, pole, filament, or candle could have a size of bar that is plastic covered in length of 30 mm, diameter of 2.5 to 3.5 mm, having a size of bar with connectors of 38-40 mm. In such an example, the quantity of light chips  200  within a single candle could be 26 pcs, in the 465-475 nm, having a serial connection. 
         [0052]    It could be mfd. using flip chip technology, having a working voltage of 70-90 Volts, with current up to 30 mA, with a pulse of up to 100 mA. The LED chip size(s) 10×18, 10×20, 10×23, 10×26 mm, depending on the pad size being used. Some additional LEDs could be 10×18 or 20×20 mm with ESP. Thickness of LED die sapphire substrate in the 200 -430 micron (0.2-0.43 mm). Thicker may be better (say −0.43 mm) as a standard for sapphire wafer. Each chip seats on it&#39;s own pad —“leg”, having no reflector on the pad. 
         [0053]    Top attach, using an eutectic placement, wire bonding: Au or Al with Au plated-chipper. Wire bonding: could be done by 1 wire to LED die, or by 2 wires on same LED die “Leg” size of L 5.0×W 0.7×T 0.7 or L 5.0×W 0.5×T 0.5 mm. LED die “Leg” goes throughout of plastic for 3.0-4.0 mm. 
         [0054]    Type of plastic (Epoxy) cover: LED compatible, phosphor compatible, no need for weather protection, bar will be insulated inside and protected Plastic (Epoxy): mixed with phosphor, molded over metal “legs” with LED dies Plastic (Epoxy). Especially shaped for better light output and distribution, cylindrical stars. Microscopic view: bar inside, single wire bonding, eutectic die attach, die thickness ˜10 mil 
         [0055]    In one embodiment, the system could be used as replacement for incandescent light bulbs filaments, since due to its shape it could also be used as replacement for “gas discharge line” in T8, T5 fluorescent tubes. There is no need for PCB (Printed Circuit Board), and the separated, independent heat sink for every LED die (chip) in a bar would provide one of the best heat dissipation ability for LED dies, due to the ratio of sizes between LED die and size of the heat sink. 
         [0056]    Very low thermal resistance between LED die and heat sink, to ambient, due to eutectic bonding process. Very wide angle of light distribution, due to a shape of pad for die attach, of plastic (epoxy) lens. No needs for secondary optics, lens are molded at the same time of production. Possibility to make heat sink electrically insulated, by using different die attachment methods. 
       CONCLUSION 
       [0057]    In concluding the detailed description, it should be noted that it would be obvious to those skilled in the art that many variations and modifications can be made to the preferred embodiment without substantially departing from the principles of the present invention. Also, such variations and modifications are intended to be included herein within the scope of the present invention as set forth in the appended claims. Further, in the claims hereafter, the structures, materials, acts and equivalents of all means or step-plus function elements are intended to include any structure, materials or acts for performing their cited functions. 
         [0058]    It should be emphasized that the above-described embodiments of the present invention, particularly any “preferred embodiments” are merely possible examples of the implementations, merely set forth for a clear understanding of the principles of the invention. Any variations and modifications may be made to the above-described embodiments of the invention without departing substantially from the spirit of the principles of the invention. All such modifications and variations are intended to be included herein within the scope of the disclosure and present invention and protected by the following claims. 
         [0059]    The present invention has been described in sufficient detail with a certain degree of particularity. The utilities thereof are appreciated by those skilled in the art. It is understood to those skilled in the art that the present disclosure of embodiments has been made by way of examples only and that numerous changes in the arrangement and combination of parts may be resorted without departing from the spirit and scope of the invention as claimed. Accordingly, the scope of the present invention is defined by the appended claims rather than the forgoing description of embodiments.